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Sample records for gram-negative sepsis melioidosis

  1. Overexpression of the endothelial protein C receptor is detrimental during pneumonia-derived gram-negative sepsis (Melioidosis.

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    Liesbeth M Kager

    Full Text Available The endothelial protein C receptor (EPCR enhances anticoagulation by accelerating activation of protein C to activated protein C (APC and mediates anti-inflammatory effects by facilitating APC-mediated signaling via protease activated receptor-1. We studied the role of EPCR in the host response during pneumonia-derived sepsis instigated by Burkholderia (B. pseudomallei, the causative agent of melioidosis, a common form of community-acquired Gram-negative (pneumosepsis in South-East Asia.Soluble EPCR was measured in plasma of patients with septic culture-proven melioidosis and healthy controls. Experimental melioidosis was induced by intranasal inoculation of B. pseudomallei in wild-type (WT mice and mice with either EPCR-overexpression (Tie2-EPCR or EPCR-deficiency (EPCR(-/-. Mice were sacrificed after 24, 48 or 72 hours. Organs and plasma were harvested to measure colony forming units, cellular influxes, cytokine levels and coagulation parameters. Plasma EPCR-levels were higher in melioidosis patients than in healthy controls and associated with an increased mortality. Tie2-EPCR mice demonstrated enhanced bacterial growth and dissemination to distant organs during experimental melioidosis, accompanied by increased lung damage, neutrophil influx and cytokine production, and attenuated coagulation activation. EPCR(-/- mice had an unremarkable response to B. pseudomallei infection as compared to WT mice, except for a difference in coagulation activation in plasma.Increased EPCR-levels correlate with accelerated mortality in patients with melioidosis. In mice, transgenic overexpression of EPCR aggravates outcome during Gram-negative pneumonia-derived sepsis caused by B. pseudomallei, while endogenous EPCR does not impact on the host response. These results add to a better understanding of the regulation of coagulation during severe (pneumosepsis.

  2. Multiplex identification of sepsis-causing Gram-negative pathogens from the plasma of infected blood.

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    Chung, Boram; Park, Chulmin; Cho, Sung-Yeon; Shin, Juyoun; Shin, Sun; Yim, Seon-Hee; Lee, Dong-Gun; Chung, Yeun-Jung

    2018-02-01

    Early and accurate detection of bacterial pathogens in the blood is the most crucial step for sepsis management. Gram-negative bacteria are the most common organisms causing severe sepsis and responsible for high morbidity and mortality. We aimed to develop a method for rapid multiplex identification of clinically important Gram-negative pathogens and also validated whether our system can identify Gram-negative pathogens with the cell-free plasm DNA from infected blood. We designed five MLPA probe sets targeting the genes specific to major Gram-negative pathogens (uidA and lacY for E. coli, ompA for A. baumannii, phoE for K. pneumoniae, and ecfX for P. aeruginosa) and one set targeting the CTX-M group 1 to identify the ESBL producing Gram-negative pathogens. All six target-specific peaks were clearly separated without any non-specific peaks in a multiplex reaction condition. The minimum detection limit was 100 fg of pathogen DNA. When we tested 28 Gram-negative clinical isolates, all of them were successfully identified without any non-specific peaks. To evaluate the clinical applicability, we tested seven blood samples from febrile patients. Three blood culture positive cases showed E. coli specific peaks, while no peak was detected in the other four culture negative samples. This technology can be useful for detection of major sepsis-causing, drug-resistant Gram-negative pathogens and also the major ESBL producing Gram-negatives from the blood of sepsis patients in a clinical setting. This system can help early initiation of effective antimicrobial treatment against Gram-negative pathogens for sepsis patients, which is very crucial for better treatment outcomes. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. VIP as a potential therapeutic agent in gram negative sepsis.

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    Ibrahim, Hiba; Barrow, Paul; Foster, Neil

    2012-12-01

    Gram negative sepsis remains a high cause of mortality and places a great burden on public health finance in both the developed and developing world. Treatment of sepsis, using antibiotics, is often ineffective since pathology associated with the disease occurs due to dysregulation of the immune system (failure to return to steady state conditions) which continues after the bacteria, which induced the immune response, have been cleared. Immune modulation is therefore a rational approach to the treatment of sepsis but to date no drug has been developed which is highly effective, cheap and completely safe to use. One potential therapeutic agent is VIP, which is a natural peptide and is highly homologous in all vertebrates. In this review we will discuss the effect of VIP on components of the immune system, relevant to gram negative sepsis, and present data from animal models. Furthermore we will hypothesise on how these studies could be improved in future and speculate on the possible different ways in which VIP could be used in clinical medicine.

  4. Cytokine profile in severe gram-positive and gram-negative abdominal sepsis

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    Surbatovic, Maja; Popovic, Nada; Vojvodic, Danilo; Milosevic, Ivan; Acimovic, Gordana; Stojicic, Milan; Veljovic, Milic; Jevdjic, Jasna; Djordjevic, Dragan; Radakovic, Sonja

    2015-01-01

    Sepsis is a principal cause of death in critical care units worldwide and consumes considerable healthcare resources. The aim of our study was to determine whether the early cytokine profile can discriminate between Gram-positive and Gram-negative bacteraemia (GPB and GNB, respectively) and to assess the prognostic value regarding outcome in critically ill patients with severe abdominal sepsis. The outcome measure was hospital mortality. Blood samples were obtained from 165 adult patients with confirmed severe abdominal sepsis. Levels of the proinflammatory mediators TNF-α, IL-8, IL-12 and IFN-γ and the anti-inflammatory mediators IL-1ra, IL-4, IL-10 and TGF-β1 were determined and correlated with the nature of the bacteria isolated from the blood culture and outcome. The cytokine profile in our study indicated that the TNF-α levels were 2-fold, IL-8 were 3.3-fold, IFN-γ were 13-fold, IL-1ra were 1.05-fold, IL-4 were 1.4-fold and IL-10 were 1.83-fold higher in the GNB group compared with the GPB group. The TNF-α levels were 4.7-fold, IL-8 were 4.6-fold, IL-1ra were 1.5-fold and IL-10 were 3.3-fold higher in the non-survivors compared with the survivors. PMID:26079127

  5. Case of a lung mass due to melioidosis in Mexico.

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    Truong, Kimberly K; Moghaddam, Samer; Al Saghbini, Samer; Saatian, Bahman

    2015-05-06

    Melioidosis, an infection caused by the gram-negative bacterium Burkholderia pseudomallei, is an important cause of pneumonia, skin infection, sepsis, and death in Southeast Asia and Australia, but is exceedingly rare in North America. Pulmonary melioidosis typically presents as acute bacterial pneumonia or cavitary lung lesions resembling tuberculosis. We report melioidosis in a 70-year-old active smoker from Mexico with no history of travel to disease-endemic areas. The patient presented with a left supraclavicular abscess and a non-cavitary, left lung mass encasing a pulmonary vein. Incision and drainage of the patient's subcutaneous abscess isolated B. pseudomallei, and fine-needle aspiration of enlarged mediastinal lymph nodes revealed the presence of intracellular gram-negative bacilli with no evidence of malignancy. Biochemical tests determined that the strain the patient acquired from Mexico is identical to only 1 other isolate from Thailand. This report highlights the blurring epidemiological borders of this organism, its rare presentation mimicking lung malignancy, and an aggressive antimicrobial treatment that resulted in resolution of the patient's symptoms.

  6. Long-term survival and function after suspected gram-negative sepsis.

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    Perl, T M; Dvorak, L; Hwang, T; Wenzel, R P

    1995-07-26

    To determine the long-term (> 3 months) survival of septic patients, to develop mathematical models that predict patients likely to survive long-term, and to measure the health and functional status of surviving patients. A large tertiary care university hospital and an associated Veterans Affairs Medical Center. From December 1986 to December 1990, a total of 103 patients with suspected gram-negative sepsis entered a double-blind, placebo-controlled efficacy trial of monoclonal antiendotoxin antibody. Of these, we followed up 100 patients for 7667 patient-months. Beginning in May 1992, we reviewed hospital records and contacted all known survivors. We measured the health status of all surviving patients. The determinants of long-term survival (up to 6 years) were identified through two Cox proportional hazard regression models: one that included patient characteristics identified at the time of sepsis (bedside model) and another that included bedside, infection-related, and treatment characteristics (overall model). Of the 60 patients in the cohort who died at a median interval of 30.5 days after sepsis, 32 died within the first month of the septic episode, seven died within 3 months, and four more died within 6 months. In the bedside multivariate model constructed to predict long-term survival, large hazard ratios (HRs) were associated with severity of underlying illness as classified by McCabe and Jackson criteria (for rapidly fatal disease, HR = 30.4, P respiratory distress syndrome (HR = 2.3; P = .02) predicted patients most likely to die. The Acute Physiology and Chronic Health Evaluation II score was not a significant predictor of outcome when either model included the simpler McCabe and Jackson classification of underlying disease severity. We compared the health status scores with norms for the general population and found that patients with resolved sepsis reported more physical dysfunction (P bedridden), suggesting that the patients' physical function

  7. Sinonasal Melioidosis in a Returned Traveller Presenting with Nasal Cellulitis and Sinusitis

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    Rebecca Sin Mei Lim

    2013-01-01

    Full Text Available We illustrate a case involving a 51-year-old man who presented to a tertiary hospital with sepsis secondary to an abscess of the nasal vestibule and pustular eruptions of the nasal mucosa. Associated cellulitis extended across the face to the eye, and mucosal thickening of the sinuses was seen on computed tomography. The patient underwent incision and drainage and endoscopic sinus surgery. Blood cultures and swabs were positive for a gram-negative bacillus, Burkholderia pseudomallei. He had multiple risk factors including travel to an endemic area. The patient received extended antibiotic therapy in keeping with published national guidelines. Melioidosis is caused by Burkholderia pseudomallei, found in the soil in Northern Australia and Asia. It is transmitted via cutaneous or inhaled routes, leading to pneumonia, skin or soft tissue abscesses, and genitourinary infections. Risk factors include diabetes, chronic lung disease, and alcohol abuse. It can exist as a latent, active, or reactivated infection. A high mortality rate has been identified in patients with sepsis. Melioidosis is endemic in tropical Northern Australia and northeastern Thailand where it is the most common cause of severe community-acquired sepsis. There is one other report of melioidosis in the literature involving orbital cellulitis and sinusitis.

  8. Radiological manifestations of melioidosis

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    Lim, K.S.; Chong, V.H.

    2010-01-01

    Melioidosis is a serious infection that is associated with high mortality. It is due to a Gram-negative bacterium, Burkholderia pseudomallei which is an environmental saprophyte found in wet soils. Melioidosis is endemic to northern Australia and the Southeast Asia. However, there is now increasing number of reports of imported cases to regions where this infection has not been previously encountered. Almost any organ can be affected. Like many other conditions, radiological imaging is an integral part of the diagnostic workup of melioidosis. Awareness of the various radiological manifestations can help direct appropriate investigations to achieve early diagnosis and the initiation of appropriate treatment. Generally, there are no known characteristic features on imaging that can specifically differentiate melioidosis from other infections. However, the 'honeycomb' appearance has been described to be characteristic for large melioidosis liver abscesses. Simultaneous involvement of various organs is also characteristics. To date, there are few data available on the radiological manifestations of melioidosis. The present pictorial essay describes melioidosis affecting the various organs.

  9. Marine Compounds with Therapeutic Potential in Gram-Negative Sepsis

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    Irina Yermak

    2013-06-01

    Full Text Available This paper concerns the potential use of compounds, including lipid A, chitosan, and carrageenan, from marine sources as agents for treating endotoxemic complications from Gram-negative infections, such as sepsis and endotoxic shock. Lipid A, which can be isolated from various species of marine bacteria, is a potential antagonist of bacterial endotoxins (lipopolysaccharide (LPSs. Chitosan is a widespread marine polysaccharide that is derived from chitin, the major component of crustacean shells. The potential of chitosan as an LPS-binding and endotoxin-neutralizing agent is also examined in this paper, including a discussion on the generation of hydrophobic chitosan derivatives to increase the binding affinity of chitosan to LPS. In addition, the ability of carrageenan, which is the polysaccharide of red alga, to decrease the toxicity of LPS is discussed. We also review data obtained using animal models that demonstrate the potency of carrageenan and chitosan as antiendotoxin agents.

  10. Common TNF-alpha, IL-1 beta, PAI-1, uPA, CD14 and TLR4 polymorphisms are not associated with disease severity or outcome from Gram negative sepsis

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    Jessen, Kirstine Marie; Lindboe, Sarah Bjerre; Petersen, Anncatrine Luisa

    2007-01-01

    consecutive adult patients with culture proven Gram negative bacteremia admitted to a Danish hospital between 2000 and 2002. Analysis for commonly described SNPs of tumor necrosis-alpha, (TNF-alpha), interleukin-1 beta (IL-1 beta), plasminogen activator-1 (PAI-1), urokinase plasminogen activator (uPA), CD14...... hazard regression analysis, increasing age, polymicrobial infection and haemoglobin levels were associated with in-hospital mortality. CONCLUSION: We did not find any association between TNF-alpha, IL-1 beta, PAI-1, uPA, CD14 and TLR4 polymorphisms and outcome of Gram negative sepsis. Other host factors...... appear to be more important than the genotypes studied here in determining the severity and outcome of Gram negative sepsis....

  11. Common TNF-α, IL-1β, PAI-1, uPA, CD14 and TLR4 polymorphisms are not associated with disease severity or outcome from Gram negative sepsis

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    Eugen-Olsen Jesper

    2007-09-01

    Full Text Available Abstract Background Several studies have investigated single nucleotide polymorphisms (SNPs in candidate genes associated with sepsis and septic shock with conflicting results. Only few studies have combined the analysis of multiple SNPs in the same population. Methods Clinical data and DNA from consecutive adult patients with culture proven Gram negative bacteremia admitted to a Danish hospital between 2000 and 2002. Analysis for commonly described SNPs of tumor necrosis-α, (TNF-α, interleukin-1β (IL-1β, plasminogen activator-1 (PAI-1, urokinase plasminogen activator (uPA, CD14 and toll-like receptor 4 (TLR4 was done. Results Of 319 adults, 74% had sepsis, 19% had severe sepsis and 7% were in septic shock. No correlation between severity or outcome of sepsis was observed for the analyzed SNPs of TNF-α, IL-1β, PAI-1, uPA, CD14 or TLR-4. In multivariate Cox proportional hazard regression analysis, increasing age, polymicrobial infection and haemoglobin levels were associated with in-hospital mortality. Conclusion We did not find any association between TNF-α, IL-1β, PAI-1, uPA, CD14 and TLR4 polymorphisms and outcome of Gram negative sepsis. Other host factors appear to be more important than the genotypes studied here in determining the severity and outcome of Gram negative sepsis.

  12. Melioidosis: reactivation during radiation therapy

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    Jegasothy, B.V.; Goslen, J.B.; Salvatore, M.A.

    1980-01-01

    Melioidosis is caused by Pseudomonas pseudomallei, a gram-negative, motile bacillus which is a naturally occurring soil saprophyte. The organism is endemic in Southeast Asia, the Philippines, Australia, and parts of Central and South America. Most human disease occurs from infection acquired in these countries. Infection with P pseudomallei may produce no apparent clinical disease. Acute pneumonitis or septicemia may result from inhalation of the organism, and inoculation into sites of trauma may cause localized skin abscesses, or the disease may remain latent and be reactivated months or years later by trauma, burns, or pneumococcal pneumonia, diabetic ketoacidosis, influenza, or bronchogenic carcinoma. The last is probably the commonest form of melioidosis seen in the United States. We present the first case of reactivation of melioidosis after radiation therapy for carcinoma of the lung, again emphasizing the need to consider melioidosis in a septic patient with a history of travel, especially to Southeast Asia

  13. Comparison of flomoxef with latamoxef in the treatment of sepsis and/or Gram-negative bacteremia in adult patients.

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    Chen, Y C; Hung, C C; Lin, S F; Chang, S C; Hsieh, W C

    1996-05-01

    The safety and efficacy of flomoxef and latamoxef were compared in the treatment of hospitalized patients with sepsis and/or Gram-negative bacteremia in a prospective, open-labelled clinical trial. Patients were randomized to receive 1 to 2 g intravenous doses of either flomoxef every 6 to 12 h, or latamoxef every 8 to 12 h. Data from 21 patients given flomoxef and 23 patients given latamoxef were included in the evaluation of efficacy. Flomoxef produced clinical cure and satisfactory microbiological responses in 85.7% and 100% of patients, respectively. These results were similar to those obtained with latamoxef (87% and 100%, respectively). In addition, no significant difference was found in mean age, sex, severity of infection, distribution of pathogens and focus of infection between the two groups. However, the flomoxef group included more patients with ultimately fatal diseases. Six patients given flomoxef and two patients given latamoxef developed superinfections caused by yeast, enterococci and Pseudomonas aeruginosa in the urinary tract. Mild and reversible adverse reactions probably related to flomoxef and latamoxef were noted in 14.3% and 13% of patients, respectively. The results of this study demonstrated that flomoxef is a safe and effective antimicrobial agent in the treatment of patients with sepsis and/or Gram-negative bacteremia.

  14. Establishment of a novel whole animal HTS technology platform for melioidosis drug discovery.

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    Lakshmanan, Umayal; Yap, Amelia; Fulwood, Justina; Yichun, Li; Hoon, Sim Siew; Lim, Jolander; Ting, Audrey; Sem, Xiao Hui; Kreisberg, Jason F; Tan, Patrick; Tan, Gladys; Flotow, Horst

    2014-01-01

    Melioidosis is a serious emerging endemic infectious disease caused by Burkholderia pseudomallei, a gram-negative pathogen. Septicemic melioidosis has a mortality rate of 50% even with treatment. Like other gram-negative bacteria, B. pseudomallei is resistant to a number of antibiotics and multi-drug resistant B. pseudomallei is beginning to be encountered in hospitals. There is a clear medical need to develop new treatment options to manage this disease. We used Burkholderia thailandensis (a BSL-2 class organism) to infect Caenorhabditis elegans and set up a surrogate whole animal infection model of melioidosis that we could run in a 384 microtitre plate and establish a whole animal HTS assay. We have optimized and validated this assay in a fluorescence-based format that can be run on our automated screening platforms. This assay has now been used to screen over 300,000 compounds from our small molecule library and we are in the process of characterizing the hits obtained and select compounds for further studies. We have thus established a biologically relevant assay technology platform to screen for antibacterial compounds and used this platform to identify new compounds that may find application in treating melioidosis infections.

  15. The TFPI-2 derived peptide EDC34 improves outcome of gram-negative sepsis.

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    Praveen Papareddy

    Full Text Available Sepsis is characterized by a dysregulated host-pathogen response, leading to high cytokine levels, excessive coagulation and failure to eradicate invasive bacteria. Novel therapeutic strategies that address crucial pathogenetic steps during infection are urgently needed. Here, we describe novel bioactive roles and therapeutic anti-infective potential of the peptide EDC34, derived from the C-terminus of tissue factor pathway inhibitor-2 (TFPI-2. This peptide exerted direct bactericidal effects and boosted activation of the classical complement pathway including formation of antimicrobial C3a, but inhibited bacteria-induced activation of the contact system. Correspondingly, in mouse models of severe Escherichia coli and Pseudomonas aeruginosa infection, treatment with EDC34 reduced bacterial levels and lung damage. In combination with the antibiotic ceftazidime, the peptide significantly prolonged survival and reduced mortality in mice. The peptide's boosting effect on bacterial clearance paired with its inhibiting effect on excessive coagulation makes it a promising therapeutic candidate for invasive Gram-negative infections.

  16. The TFPI-2 derived peptide EDC34 improves outcome of gram-negative sepsis.

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    Papareddy, Praveen; Kalle, Martina; Sørensen, Ole E; Malmsten, Martin; Mörgelin, Matthias; Schmidtchen, Artur

    2013-01-01

    Sepsis is characterized by a dysregulated host-pathogen response, leading to high cytokine levels, excessive coagulation and failure to eradicate invasive bacteria. Novel therapeutic strategies that address crucial pathogenetic steps during infection are urgently needed. Here, we describe novel bioactive roles and therapeutic anti-infective potential of the peptide EDC34, derived from the C-terminus of tissue factor pathway inhibitor-2 (TFPI-2). This peptide exerted direct bactericidal effects and boosted activation of the classical complement pathway including formation of antimicrobial C3a, but inhibited bacteria-induced activation of the contact system. Correspondingly, in mouse models of severe Escherichia coli and Pseudomonas aeruginosa infection, treatment with EDC34 reduced bacterial levels and lung damage. In combination with the antibiotic ceftazidime, the peptide significantly prolonged survival and reduced mortality in mice. The peptide's boosting effect on bacterial clearance paired with its inhibiting effect on excessive coagulation makes it a promising therapeutic candidate for invasive Gram-negative infections.

  17. Prognostic factors and monomicrobial necrotizing fasciitis: gram-positive versus gram-negative pathogens

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    Hsu Wei-Hsiu

    2011-01-01

    Full Text Available Abstract Background Monomicrobial necrotizing fasciitis is rapidly progressive and life-threatening. This study was undertaken to ascertain whether the clinical presentation and outcome for patients with this disease differ for those infected with a gram-positive as compared to gram-negative pathogen. Methods Forty-six patients with monomicrobial necrotizing fasciitis were examined retrospectively from November 2002 to January 2008. All patients received adequate broad-spectrum antibiotic therapy, aggressive resuscitation, prompt radical debridement and adjuvant hyperbaric oxygen therapy. Eleven patients were infected with a gram-positive pathogen (Group 1 and 35 patients with a gram-negative pathogen (Group 2. Results Group 2 was characterized by a higher incidence of hemorrhagic bullae and septic shock, higher APACHE II scores at 24 h post-admission, a higher rate of thrombocytopenia, and a higher prevalence of chronic liver dysfunction. Gouty arthritis was more prevalent in Group 1. For non-survivors, the incidences of chronic liver dysfunction, chronic renal failure and thrombocytopenia were higher in comparison with those for survivors. Lower level of serum albumin was also demonstrated in the non-survivors as compared to those in survivors. Conclusions Pre-existing chronic liver dysfunction, chronic renal failure, thrombocytopenia and hypoalbuminemia, and post-operative dependence on mechanical ventilation represent poor prognostic factors in monomicrobial necrotizing fasciitis. Patients with gram-negative monobacterial necrotizing fasciitis present with more fulminant sepsis.

  18. Expression and function of macrophage migration inhibitory factor (MIF in melioidosis.

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    W Joost Wiersinga

    2010-02-01

    Full Text Available Macrophage migration inhibitory factor (MIF has emerged as a pivotal mediator of innate immunity and has been shown to be an important effector molecule in severe sepsis. Melioidosis, caused by Burkholderia pseudomallei, is an important cause of community-acquired sepsis in Southeast-Asia. We aimed to characterize the expression and function of MIF in melioidosis.MIF expression was determined in leukocytes and plasma from 34 melioidosis patients and 32 controls, and in mice infected with B. pseudomallei. MIF function was investigated in experimental murine melioidosis using anti-MIF antibodies and recombinant MIF. Patients demonstrated markedly increased MIF mRNA leukocyte and MIF plasma concentrations. Elevated MIF concentrations were associated with mortality. Mice inoculated intranasally with B. pseudomallei displayed a robust increase in pulmonary and systemic MIF expression. Anti-MIF treated mice showed lower bacterial loads in their lungs upon infection with a low inoculum. Conversely, mice treated with recombinant MIF displayed a modestly impaired clearance of B. pseudomallei. MIF exerted no direct effects on bacterial outgrowth or phagocytosis of B. pseudomallei.MIF concentrations are markedly elevated during clinical melioidosis and correlate with patients' outcomes. In experimental melioidosis MIF impaired antibacterial defense.

  19. Usefulness of gram staining of blood collected from total parenteral nutrition catheter for rapid diagnosis of catheter-related sepsis.

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    Moonens, F; el Alami, S; Van Gossum, A; Struelens, M J; Serruys, E

    1994-01-01

    The accuracy of Gram staining of blood drawn from catheters used to administer total parenteral nutrition was compared with paired quantitative blood cultures for the diagnosis of catheter-related sepsis. Gram staining was positive in 11 of 18 episodes of catheter-related sepsis documented by quantitative culture (sensitivity, 61%) but in none of the 5 episodes of fever unrelated to catheter infection. Thus, this procedure enabled the rapid presumptive diagnosis and guidance of antimicrobial therapy for total parenteral nutrition catheter sepsis, with a positive predictive value of 100% and a negative predictive value of 42%. PMID:7521359

  20. [Antimicrobial therapy in severe infections with multidrug-resistant Gram-negative bacterias].

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    Duszyńska, Wiesława

    2010-01-01

    Multidrug-resistant Gram-negative bacteria pose a serious and rapidly emerging threat to patients in healthcare settings, and are especially prevalent and problematic in intensive therapy units. Recently, the emergence of pandrug-resistance in Gram-negative bacteria poses additional concerns. This review examines the clinical impact and epidemiology of multidrug-resistant Gram-negative bacteria as a cause of increased morbidity and mortality among ITU patients. Beta-lactamases, cephalosporinases and carbapenemases play the most important role in resistance to antibiotics. Despite the tendency to increased resistance, carbapenems administered by continuous infusion remain the most effective drugs in severe sepsis. Drug concentration monitoring, albeit rarely used in practice, is necessary to ensure an effective therapeutic effect.

  1. Melioidosis in Malaysia: A Review of Case Reports

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    Kingsley, Paul Vijay; Leader, Mark; Nagodawithana, Nandika Suranjith; Tipre, Meghan; Sathiakumar, Nalini

    2016-01-01

    Background Melioidosis is a tropical infectious disease associated with significant mortality due to early onset of sepsis. Objective We sought to review case reports of melioidosis from Malaysia. Methods We conducted a computerized search of literature resources including PubMed, OVID, Scopus, MEDLINE and the COCHRANE database to identify published case reports from 1975 to 2015. We abstracted information on clinical characteristics, exposure history, comorbid conditions, management and outc...

  2. Acute disseminated melioidosis giving rise to pneumonia and renal abscesses complicated with thrombotic thrombocytopenic purpura in a post partum woman: a case report.

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    Wijewickrama, Piyumi Sachindra Alwis; Weerakoon, Rohini

    2017-11-29

    Melioidosis is an established endemic infection in Sri Lanka, caused by Burkholderia pseudomallei, a gram negative bacterium distributed in saprophytes in soil and surface water. Main mode of transmission is via percutaneous inoculation. Pneumonia is the most common presentation in acute disease. We report a 33 year old previously healthy Sinhalese female with an occupational exposure to surface water in paddy fields, who was on postpartum day 6 following an uncomplicated pregnancy and delivery via an elective caesarian section. She presented with a 1 day history of breathlessness, preceded by a brief episode of fever. She had occasional right side coarse crackles and pitting oedema of both lower limbs. Shortly after admission, she developed type one respiratory failure needing invasive mechanical ventilation. Initial chest x-ray revealed slight obliteration of right medial diaphragmatic border while echocardiogram revealed moderate pulmonary hypertension. Computed tomography pulmonary angiogram excluded a pulmonary embolism, but revealed bilateral multi-lobar consolidation. Abdominal computed tomography demonstrated bilateral pyelonephritis with renal abscesses. As initial cultures were inconclusive, melioidosis antibody levels were done due to high degree of suspicion, which was found to be positive with a titer of 1:2560. A diagnosis of melioidosis was made based on the suggestive clinical picture, exposure history and the highly positive antibody level. She developed left side focal seizures together with thrombocytopenia and microangiopathic haemolytic anemia, suggestive of thrombotic thrombocytopenic purpura. Magnetic resonance imaging of brain was negative for cerebral abscesses but revealed extensive minute haemorrhagic foci throughout the cerebrum. Thus, the final diagnosis was acute melioidosis causing pneumonia and renal abscesses, complicated with thrombotic thrombocytopenic purpura and sepsis. She demonstrated dramatic response to high dose meropenem

  3. Unrevealing culture-negative severe sepsis

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    de Prost, Nicolas; Razazi, Keyvan; Brun-Buisson, Christian

    2013-01-01

    Sepsis involves a wide array of sources and microorganisms, only a fraction of which are microbiologically documented. Culture-negative sepsis poses special diagnostic challenges to both clinicians and microbiologists and further questions the validity of sepsis definitions.

  4. Altered glucose kinetics in diabetic rats during Gram-negative infection

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    Lang, C.H.; Dobrescu, C.; Bagby, G.J.; Spitzer, J.J.

    1987-01-01

    The present study examined the purported exacerbating effect of sepsis on glucose metabolism in diabetes. Diabetes was induced in rats by an intravenous injection of 70 or 45 mg/kg streptozotocin. The higher dose produced severe diabetes, whereas the lower dose of streptozotocin produced a miler, latent diabetes. After a chronic diabetic state had developed for 4 wk, rats had catheters implanted and sepsis induced by intraperitoneal injections of live Escherichia coli. After 24 h of sepsis the blood glucose concentration was unchanged in nondiabetics and latent diabetics, but glucose decreased from 15 to 8 mM in the septic severe diabetic group. This decrease in blood glucose was not accompanied by alterations in the plasma insulin concentration. Glucose turnover, assessed by the constant intravenous infusion of [6- 3 H]- and [U- 14 C]glucose, was elevated in the severe diabetic group, compared with either latent diabetics or nondiabetics. Sepsis increased the rate of glucose disappearance in nondiabetic rats but had no effect in either group of diabetic animals. Sepsis also failed to alter the insulinogenic index, used to estimate the insulin secretory capacity, in diabetic rats. Thus the present study suggests that the imposition of nonlethal Gram-negative sepsis on severe diabetic animals does not further impair glucose homeostasis and that the milder latent diabetes was not converted to a more severe diabetic state by the septic challenge

  5. Thrombocytopenia impairs host defense in gram-negative pneumonia-derived sepsis in mice

    NARCIS (Netherlands)

    de Stoppelaar, Sacha F.; van 't Veer, Cornelis; Claushuis, Theodora A. M.; Albersen, Bregje J. A.; Roelofs, Joris J. T. H.; van der Poll, Tom

    2014-01-01

    Thrombocytopenia is a common finding in sepsis and associated with a worse outcome. We used a mouse model of pneumonia-derived sepsis caused by the human pathogen Klebsiella pneumoniae to study the role of platelets in host response to sepsis. Platelet counts (PCs) were reduced to less than a median

  6. Extended spectrum beta-lactamases in urinary gram-negative bacilli and their susceptibility pattern

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    Mumtaz, S.

    2008-01-01

    Beta-lactamases of gram-negative bacteria are the most important mechanism of resistance against beta lactams. Two types of beta-lactamases can confer resistance against third generation cephalosporins inducible Chromosomal beta -lactamases and extended-spectrum beta-lactamases. The extended-spectrum beta lactamases producing Strains of Enterobacteriaceae have emerged as a major problem in hospitalized as well as community based infections resulting in range of infections from uncomplicated urinary tract infection to life threatening sepsis. The study was conducted at the Microbiology Department of Fauji Foundation Hospital, Rawalpindi over a period of two years (April 2004-March 2006). Multidrug resistance and extended spectrum beta-lactamases production was studied in 111 enteric Gram-negative bacilli isolated from urine of symptomatic patients (1- 70 years) including males and females from indoor and outdoor patients by using double disc diffusion technique. Prevalence of extended-spectrum beta-lactamases production was seen in 71 (61.2%) enteric gram-negative organisms, the most prevalent gram-negative organism was Klebsiella pneumoniae 40 (71.4%) followed by Escherichia coli 27 (62.8%) and Pseudomonas aeruginosa 3 (25%). The extended-spectrum beta-lactamases producers were more prevalent in indoor patients 63 (88.7%) compared to outdoor patients 8 (11.3%), more in females 43 (60.6%) than males, 28 (39.4%). The extended-spectrum beta-lactamases producing gram-negative rods had more antibiotic-resistant profile than non-producers. All enteric gram negative rods should be tested for the production of extended-spectrum beta-lactamases in routine microbiology laboratory. (author)

  7. Severe coinfection of melioidosis and dengue fever in northeastern Brazil: first case report

    Directory of Open Access Journals (Sweden)

    Rafael Nogueira Macedo

    2012-02-01

    Full Text Available This report focuses on a fatality involving severe dengue fever and melioidosis in a 28-year-old truck driver residing in Pacoti in northeastern Brazil. He exhibited long-term respiratory symptoms (48 days and went through a wide-ranging clinical investigation at three hospitals, after initial clinical diagnoses of pneumonia, visceral leishmaniasis, tuberculosis, and fungal sepsis. After death, Burkholderia pseudomallei was isolated in a culture of ascitic fluid. Dengue virus type 1 was detected by polymerase chain reaction in cerebrospinal fluid (CSF; this infection was the cause of death. This description reinforces the need to consider melioidosis among the reported differential diagnoses of community-acquired infections where both melioidosis and dengue fever are endemic.

  8. Procalcitonin levels in gram-positive, gram-negative, and fungal bloodstream infections.

    Science.gov (United States)

    Leli, Christian; Ferranti, Marta; Moretti, Amedeo; Al Dhahab, Zainab Salim; Cenci, Elio; Mencacci, Antonella

    2015-01-01

    Procalcitonin (PCT) can discriminate bacterial from viral systemic infections and true bacteremia from contaminated blood cultures. The aim of this study was to evaluate PCT diagnostic accuracy in discriminating Gram-positive, Gram-negative, and fungal bloodstream infections. A total of 1,949 samples from patients with suspected bloodstream infections were included in the study. Median PCT value in Gram-negative (13.8 ng/mL, interquartile range (IQR) 3.4-44.1) bacteremias was significantly higher than in Gram-positive (2.1 ng/mL, IQR 0.6-7.6) or fungal (0.5 ng/mL, IQR 0.4-1) infections (P Gram-negatives from Gram-positives at the best cut-off value of 10.8 ng/mL and an AUC of 0.944 (95% CI 0.919-0.969, P Gram-negatives from fungi at the best cut-off of 1.6 ng/mL. Additional results showed a significant difference in median PCT values between Enterobacteriaceae and nonfermentative Gram-negative bacteria (17.1 ng/mL, IQR 5.9-48.5 versus 3.5 ng/mL, IQR 0.8-21.5; P Gram-negative from Gram-positive and fungal bloodstream infections. Nevertheless, its utility to predict different microorganisms needs to be assessed in further studies.

  9. A Case of Constrictive Pericarditis Associated with Melioidosis in an Immunocompetent Patient Treated by Pericardiectomy

    Science.gov (United States)

    Lu, Hou Tee; Ramsamy, Gunasekaran; Lee, Chuey Yan; Syed Hamid, Syed Rasul G.; Kan, Foong Kee; Nordin, Rusli Bin

    2018-01-01

    Patient: Male, 38 Final Diagnosis: Constrictive pericarditis Symptoms: Shortness of breath Medication: — Clinical Procedure: Pericardiocentesis • pericardiectomy Specialty: Cardiology Objective: Unusual clinical course Background: Melioidosis is a rare tropical bacterial infection caused by the Gram-negative soil saprophyte, Burkholderia pseudomallei. Melioidosis can mimic a variety of diseases due to its varied presentation, and unless it is treated rapidly, it can be fatal. A rare case of melioidosis, with pericarditis and pericardial effusion, is described, which demonstrates the value of early diagnosis with echocardiography and pericardiocentesis. Case Report: A 38-year-old native (Iban) East Malaysian man presented with shortness of breath and tachycardia. Transthoracic echocardiography (TTE) showed cardiac tamponade. Urgent pericardiocentesis drained a large amount of purulent pericardial fluid that grew Burkholderia pseudomallei. Despite appropriate dose and duration of intravenous treatment with ceftazidime followed by meropenem, the patient developed recurrent pericardial effusion and right heart failure due to constrictive pericarditis. The diagnosis of constrictive pericarditis was confirmed by computed tomography (CT) and surgical exploration. Following pericardiectomy, his symptoms resolved, but patient follow-up was recommended for possible sequelae of constrictive pericarditis. Conclusions: After the onset of melioidosis pericarditis, the authors recommend follow-up and surveillance for possible complication of constrictive pericarditis. PMID:29551765

  10. Molecular investigations of a locally acquired case of melioidosis in Southern AZ, USA.

    Directory of Open Access Journals (Sweden)

    David M Engelthaler

    2011-10-01

    Full Text Available Melioidosis is caused by Burkholderia pseudomallei, a Gram-negative bacillus, primarily found in soils in Southeast Asia and northern Australia. A recent case of melioidosis in non-endemic Arizona was determined to be the result of locally acquired infection, as the patient had no travel history to endemic regions and no previous history of disease. Diagnosis of the case was confirmed through multiple microbiologic and molecular techniques. To enhance the epidemiological analysis, we conducted several molecular genotyping procedures, including multi-locus sequence typing, SNP-profiling, and whole genome sequence typing. Each technique has different molecular epidemiologic advantages, all of which provided evidence that the infecting strain was most similar to those found in Southeast Asia, possibly originating in, or around, Malaysia. Advancements in new typing technologies provide genotyping resolution not previously available to public health investigators, allowing for more accurate source identification.

  11. A STUDY OF LABORATORY PROFILE OF NEONATAL SEPSIS AT NICU (SNCU, WARANGAL

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    Sudhakar

    2016-05-01

    Full Text Available BACKGROUND Of the 130 million babies born worldwide each year, 26 million are born in India alone. Four million babies die with in first 30 days of birth and another four million are stillborn. Newborn mortality represents 40% of all deaths of children less than five years of age. Of the four million deaths each year, nearly 98% occur in developing countries. Globally major causes of neonatal deaths are due to preterm births (28%, sepsis or pneumonia (26% and birth asphyxia (23%. Neonatal sepsis is one of the commonest causes of neonatal deaths in the developing world accounting to 30-50% of all neonatal deaths per year. The present study is intended to help the practising paediatrician to accurately diagnose the sepsis early using the specific laboratory tests and avert the progression of the disease. METHODS It is an observational cross-sectional study in NICU, Mahatma Gandhi Memorial Hospital. The study was conducted in the period November 2013 to October 2014. After admission, detailed history and thorough clinical examination was done. Required data was entered in a pre-set proforma and statistical analysis was done. Blood culture was sent. Bacterial culture and sensitivity was checked. RESULTS In proven sepsis, 50.25% were Gram-positive, 43.65% were Gram-negative and 6.09% were fungal sepsis Candida. Klebsiella (32.48% was the most common organism followed by Coagulase positive Staphylococcus (25.38% and CONS (20.81%. In this study, Gram-negative sepsis was more common in preterm and Gram-positive sepsis was more common in term neonates. Early onset sepsis was the common presentation of proven sepsis, Klebsiella was common organism causing EOS. Whereas CONS was commonest causing late onset sepsis. Among Gram-negative organisms, 58.1% and 27.9% were resistant to cefotaxime and ampicillin+sulbactam respectively. Among Gram-positive isolates, 35% and 22% were resistant to cefotaxime and ampicillin+sulbactam respectively. Klebsiella, most

  12. Procalcitonin Levels in Gram-Positive, Gram-Negative, and Fungal Bloodstream Infections

    Directory of Open Access Journals (Sweden)

    Christian Leli

    2015-01-01

    Full Text Available Procalcitonin (PCT can discriminate bacterial from viral systemic infections and true bacteremia from contaminated blood cultures. The aim of this study was to evaluate PCT diagnostic accuracy in discriminating Gram-positive, Gram-negative, and fungal bloodstream infections. A total of 1,949 samples from patients with suspected bloodstream infections were included in the study. Median PCT value in Gram-negative (13.8 ng/mL, interquartile range (IQR 3.4–44.1 bacteremias was significantly higher than in Gram-positive (2.1 ng/mL, IQR 0.6–7.6 or fungal (0.5 ng/mL, IQR 0.4–1 infections (P<0.0001. Receiver operating characteristic analysis showed an area under the curve (AUC for PCT of 0.765 (95% CI 0.725–0.805, P<0.0001 in discriminating Gram-negatives from Gram-positives at the best cut-off value of 10.8 ng/mL and an AUC of 0.944 (95% CI 0.919–0.969, P<0.0001 in discriminating Gram-negatives from fungi at the best cut-off of 1.6 ng/mL. Additional results showed a significant difference in median PCT values between Enterobacteriaceae and nonfermentative Gram-negative bacteria (17.1 ng/mL, IQR 5.9–48.5 versus 3.5 ng/mL, IQR 0.8–21.5; P<0.0001. This study suggests that PCT may be of value to distinguish Gram-negative from Gram-positive and fungal bloodstream infections. Nevertheless, its utility to predict different microorganisms needs to be assessed in further studies.

  13. Environmental management procedures following fatal melioidosis in a captive chimpanzee (Pan troglodytes).

    Science.gov (United States)

    Sommanustweechai, Angkana; Kasantikul, Tanit; Somsa, Wachirawit; Wongratanacheewin, Surasakdi; Sermswan, Rasana W; Kongmakee, Piyaporn; Thomas, Warissara; Kamolnorranath, Sumate; Siriaroonrat, Boripat; Bush, Mitchell; Banlunara, Wijit

    2013-06-01

    A 40-yr-old male captive chimpanzee (Pan troglodytes) presented with depression and anorexia for 7 days. The tentative diagnosis, following a physical examination under anesthesia, was pneumonia with sepsis. Despite antibiotic treatment and supportive care the chimpanzee died a week following presentation. Gross pathology confirmed severe purulent pneumonia and diffuse hepatosplenic abscesses. Detected in serum at the time of the initial examination, the melioidosis serum antibody titer was elevated (> 1:512). Soil samples were collected from three sites in the exhibit at three depths of 5, 15, and 30 cm. By direct and enrichment culture, positive cultures for Burkholderia pseudomallei were found at 5 and 15 cm in one site. The other two sites were positive by enrichment culture at the depth of 5 cm. To prevent disease in the remaining seven troop members, they were relocated to permit a soil treatment with calcium oxide. The exhibit remained empty for approximately 1 yr before the chimpanzees were returned. During that period, the soil in the exhibit area was again cultured as before and all samples were negative for B. pseudomallei. Following the soil treatment in the exhibit, all chimpanzees have remained free of clinical signs consistent with melioidosis.

  14. Gram-negative, but not Gram-positive, bacteria elicit strong PGE2 production in human monocytes.

    Science.gov (United States)

    Hessle, Christina C; Andersson, Bengt; Wold, Agnes E

    2003-12-01

    Gram-positive and Gram-negative bacteria induce different cytokine patterns in human mononuclear cells. We have seen that Gram-positives preferentially induce IL-12 and TNF-alpha, whereas Gram-negatives induce more IL-10, IL-6, and IL-8. In this study, we compared the capacity of these two groups of bacteria to induce PGE2. Monocytes stimulated with Gram-negative bacterial species induced much more PGE2 than did Gram-positive bacteria (5600 +/- 330 vs. 1700 +/- 670 pg/mL, p Gram-positive and Gram-negative bacteria. We suggest that Gram-positive and Gram-negative bacteria may stimulate different innate effector functions; Gram-positive bacteria promoting cell-mediated effector functions whereas Gram-negative bacteria inducing mediators inhibiting the same.

  15. Fatal Septicemic Melioidosis in a Young Military Person Possibly Co-Infected With Leptospira Interrogans and Orientia Tsutsugamushi

    Directory of Open Access Journals (Sweden)

    Po-Liang Lu

    2005-04-01

    Full Text Available Concurrent melioidosis, leptospirosis, and scrub typhus after rural activities is rarely reported. A 19-year-old previously healthy man had fever onset after 2 weeks of military training. Pneumonia became evident on the fifth day of fever under intravenous penicillin and oral minocycline therapy. Acute respiratory failure developed the next day with shock and acute renal and liver function deterioration, which resulted in death. Blood cultures on the third and fifth days grew Burkholderia pseudomallei. Serology revealed leptospirosis and scrub typhus. The emergence of melioidosis in Taiwan and this death without antibiotic treatment for melioidosis alert us that B. pseudomallei should be included as a possible pathogen of pneumonia and sepsis, especially after rural activities.

  16. Melioidosis in acute cholangitis of diabetic patient: a forgotten diagnosis

    Directory of Open Access Journals (Sweden)

    Mohamad N

    2012-08-01

    Full Text Available Nasir Mohamad,1 Suresh Ponnusamy,2 Sunita Devi,3 Rishya Manikam,4 Ilya Irinaz Idrus,1 Nor Hidayah Abu Bakar51Department of Emergency Medicine, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Malaysia; 2AIMST University, Bedong, Malaysia; 3Hospital Sultan Abdul Halim, Sungai Petani, Malaysia; 4University Malaya Medical Centre, Kuala Lumpur, Malaysia; 5Department of Pathology, Hospital Raja Perempuan Zainab II, Kota Bharu, MalaysiaAbstract: Melioidosis presents with a wide range of clinical presentations, which include severe community-acquired pneumonia, septicemia, central nervous system infection, and less severe soft tissue infection. Hence, its diagnosis depends heavily on the clinical microbiology laboratory for culture. In this case report, we describe an atypical presentation of melioidosis in a 52-year-old man who had fever, right upper-abdominal pain, and jaundice for 15 days. Melioidosis caused by Burkholderia pseudomallei was subsequently diagnosed from blood culture. As a primary care physician, high suspicion index is of great importance. High suspicion index of melioidosis in a high-risk group patient, such as the patient with diabetes mellitus and diabetic foot, is crucial in view of atypical presentations of pseudomonas sepsis. A correct combination of antibiotic administration in the early phase of therapy will determine its successful outcome.Keywords: Burkholderia pseudomallei, atypical, high suspicion, primary care

  17. Rapid and reliable identification of Gram-negative bacteria and Gram-positive cocci by deposition of bacteria harvested from blood cultures onto the MALDI-TOF plate.

    Science.gov (United States)

    Barnini, Simona; Ghelardi, Emilia; Brucculeri, Veronica; Morici, Paola; Lupetti, Antonella

    2015-06-18

    Rapid identification of the causative agent(s) of bloodstream infections using the matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) methodology can lead to increased empirical antimicrobial therapy appropriateness. Herein, we aimed at establishing an easier and simpler method, further referred to as the direct method, using bacteria harvested by serum separator tubes from positive blood cultures and placed onto the polished steel target plate for rapid identification by MALDI-TOF. The results by the direct method were compared with those obtained by MALDI-TOF on bacteria isolated on solid media. Identification of Gram-negative bacilli was 100 % concordant using the direct method or MALDI-TOF on isolated bacteria (96 % with score > 2.0). These two methods were 90 % concordant on Gram-positive cocci (32 % with score > 2.0). Identification by the SepsiTyper method of Gram-positive cocci gave concordant results with MALDI-TOF on isolated bacteria in 87 % of cases (37 % with score > 2.0). The direct method herein developed allows rapid identification (within 30 min) of Gram-negative bacteria and Gram-positive cocci from positive blood cultures and can be used to rapidly report reliable and accurate results, without requiring skilled personnel or the use of expensive kits.

  18. Veillonella, Firmicutes: Microbes disguised as Gram negatives

    DEFF Research Database (Denmark)

    Vesth, Tammi Camilla; Ozen, Asli; Andersen, Sandra Christine

    2013-01-01

    Negativicutes, including the genus Veillonella, stain Gram negative. Veillonella are among the most abundant organisms of the oral and intestinal microflora of animals and humans, in spite of being strict anaerobes. In this work, the genomes of 24 Negativicutes, including eight Veillonella spp., are compared......, with the exception of a shared LPS biosynthesis pathway. The clade within the class Negativicutes to which the genus Veillonella belongs exhibits unique properties, most of which are in common with Gram-positives and some with Gram negatives. They are only distantly related to Clostridia, but are even less closely...... related to Gram-negative species. Though the Negativicutes stain Gram-negative and possess two membranes, the genome and proteome analysis presented here confirm their place within the (mainly) Gram positive phylum of the Firmicutes. Further studies are required to unveil the evolutionary history...

  19. The Causes of Post-Operative Meningitis: The Comparison Of Gram-Negative and Gram-Positive Pathogens.

    Science.gov (United States)

    Kurtaran, Behice; Kuscu, Ferit; Ulu, Aslihan; Inal, Ayse Seza; Komur, Suheyla; Kibar, Filiz; Cetinalp, Nuri Eralp; Ozsoy, Kerem Mazhar; Arslan, Yusuf Kemal; Aksu, Hasan Salih; Tasova, Yesim

    2017-06-20

    In this study, we aim to determine the microbiological etiology in critically ill neurosurgical patients with nosocomial meningitis (NM) and show the impact of Gram-negative rods and differences of patient's characteristics, clinical and prognostic measures between Gram-negative and Gram-positive meningitis. In this prospective, one center study we reviewed all adult patients hospitalized during a 12-year period and identified pathogens isolated from post-neurosurgical cases of NM. Demographic, clinical, and treatment characteristics were noted from the medical records. Of the 134 bacterial NM patients, 78 were male and 56 were female, with a mean age of 46±15.9 and median age of 50 (18-80) years. 141 strains isolated; 82 (58.2%) were Gram negative, 59 (41.8%) were Gram positive. Most common isolated microorganism was Acinetobacter baumannii (%34.8). In comparison of mortality data shows that the patients who have meningitis with Gram-negative pathogens have higher mortality than with Gram positives (p=0.034). The duration between surgery and meningitis was shorter in Gram negative meningitis cases compared to others (p=0.045) but the duration between the diagnosis and death was shorter in Gram-positive meningitis cases compared to Gram negatives (p= 0.017). CSF protein and lactate level were higher and glucose level was lower in cases of NM with Gram negatives (p value were respectively, 0.022, 0.039 and 0.049). As conclusions; in NM, Gram-negative pathogens were seen more frequently; A.baumanni was the predominant pathogen; and NM caused by Gram negatives had worse clinical and laboratory characteristic and prognostic outcome than Gram positives.

  20. Pulmonary dynamics of radiolabelled erythrocytes and leucocytes in early gram-negative sepsis in pigs

    International Nuclear Information System (INIS)

    Walther, Sten; Wenyao, Shi; Lennquist, Sten

    1999-01-01

    objective: to study the pulmonary dynamic of erythrocytes and leucocytes in vivo in early experimental sepsis. design: open, experimental study. setting: academic research laboratory, Sweden. material: 10 adolescent, domestic pigs. interventions: technetium (Tc 99) labelling of erythrocytes (n=5) and indium (In 111) labelling of autologous leucocytes (n=10). sepsis was induced by endotoxin (n=4) or live Escherichia Coli (n=3), given intravenously. major outcome measures: regional pulmonary scintigraphy, central haemodynamics and gas exchange followed for 180 minutes. results: septic animals developed arterial hypoxia, pulmonary hypertension and systemic hypotension. They also had an early increase in mean (SD) regional pulmonary erythrocyte and leucocyte counts (+10.3(7.7%) and + 12.0 (3.5%) respectively) with simultaneous maximum 27-32 minutes after the start of the septic insult. Conclusions: The immediate sepsis-induced pulmonary accumulation of leucocytes as detected by external scintigraphy can be ascribed at least in part, to a simultaneous sepsis-induced increase in pulmonary blood volume. 3 figs., 1 tab., 19 refs

  1. Successful liver transplantation from donor with Plesiomonas shigelloides sepsis after freshwater drowning: case report and review of literature on gram-negative bacterial aspiration during drowning and utilization of organs from bacteremic donors.

    Science.gov (United States)

    Bonatti, Hugo; Sifri, Costi; Sawyer, Robert G

    2012-04-01

    Plesiomonas shigelloides is a freshwater, non-fermentative gram-negative bacillus associated with diarrheal disease. Rare cases of invasive infection in human beings usually involve immunosuppressed individuals. We report a patient who underwent successful liver transplantation (LT) using a graft from a 14-year-old boy who had drowned in a freshwater lake. PUBMED was searched for both reported drowning victims with sepsis and outcomes of LT using organs from infected donors. Our patient received prophylactic piperacillin-tazobactam, which was switched to cefepime one day after transplantation when gram-negative bacteria grew in blood cultures of the donor. The next day, the organism was identified as P. shigelloides resistant to third- and fourth-generation cephalosporins; ciprofloxacin was given for seven days, and surveillance cultures remained negative. After an uneventful course the patient was discharged on day 10 after LT without signs of infection and is alive with a well-functioning graft. Literature review revealed one case of P. shigelloides in a potential allograft, in which the organism was isolated from heart valves of a drowning victim; the organs were discarded. Reports of freshwater drowning show that bacteremia is universally found post-mortem. Isolated pathogens correspond to specimens from the drowning site, with Aeromonas spp. being the most common and many other microorganisms described anecdotally. Livers from infected donors have been used, in most cases with good results if the recipient and, when possible, donor were treated appropriately; however, cases of fatal pathogen transmission have been reported. This is the first reported case of a LT using a graft from a donor with P. shigelloides sepsis. Drowning victims should be considered potentially infected with rare pathogens and therefore represent extended-criteria donors.

  2. Distribution of multi-resistant Gram-negative versus Gram-positive bacteria in the hospital inanimate environment.

    Science.gov (United States)

    Lemmen, S W; Häfner, H; Zolldann, D; Stanzel, S; Lütticken, R

    2004-03-01

    We prospectively studied the difference in detection rates of multi-resistant Gram-positive and multi-resistant Gram-negative bacteria in the inanimate environment of patients harbouring these organisms. Up to 20 different locations around 190 patients were surveyed. Fifty-four patients were infected or colonized with methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant enterococci (VRE) and 136 with multi-resistant Gram-negative bacteria. The environmental detection rate for MRSA or VRE was 24.7% (174/705 samples) compared with 4.9% (89/1827 samples) for multi-resistant Gram-negative bacteria (PGram-positive bacteria were isolated more frequently than Gram-negatives from the hands of patients (PGram-positive and Gram-negative isolates. Our results suggest that the inanimate environment serves as a secondary source for MRSA and VRE, but less so for Gram-negative bacteria. Thus, strict contact isolation in a single room with complete barrier precautions is recommended for MRSA or VRE; however, for multi-resistant Gram-negative bacteria, contact isolation with barrier precautions for close contact but without a single room seems sufficient. This benefits not only the patients, but also the hospital by removing some of the strain placed on already over-stretched resources.

  3. Gram-negative diabetic foot osteomyelitis: risk factors and clinical presentation.

    Science.gov (United States)

    Aragón-Sánchez, Javier; Lipsky, Benjamin A; Lázaro-Martínez, Jose L

    2013-03-01

    Osteomyelitis frequently complicates infections in the feet of patients with diabetes. Gram-positive cocci, especially Staphylococcus aureus, are the most commonly isolated pathogens, but gram-negative bacteria also cause some cases of diabetic foot osteomyelitis (DFO). These gram-negatives require different antibiotic regimens than those commonly directed at gram-positives. There are, however, few data on factors related to their presence and how they influence the clinical picture. We conducted a retrospective study to determine the variables associated with the isolation of gram-negative bacteria from bone samples in cases of DFO and the clinical presentation of these infections. Among 341 cases of DFO, 150 had a gram-negative isolate (alone or combined with a gram-positive isolate) comprising 44.0% of all patients and 50.8% of those with a positive bone culture. Compared with gram-positive infections, wounds with gram-negative organisms more often had a fetid odor, necrotic tissue, signs of soft tissue infection accompanying osteomyelitis, and clinically severe infection. By multivariate analysis, the predictive variables related to an increased likelihood of isolating gram-negatives from bone samples were glycated hemoglobin gram-negatives had a statistically significantly higher prevalence of leukocytosis and higher white blood cell counts than those without gram-negatives. In conclusion, gram-negative organisms were isolated in nearly half of our cases of DFO and were associated with more severe infections, higher white blood cell counts, lower glycated hemoglobin levels, and wounds of traumatic etiology.

  4. Drug-resistant gram-negative uropathogens: A review.

    Science.gov (United States)

    Khoshnood, Saeed; Heidary, Mohsen; Mirnejad, Reza; Bahramian, Aghil; Sedighi, Mansour; Mirzaei, Habibollah

    2017-10-01

    Urinary tract infection(UTI) caused by Gram-negative bacteria is the second most common infectious presentation in community medical practice. Approximately 150 million people are diagnosed with UTI each year worldwide. Drug resistance in Gram-negative uropathogens is a major global concern which can lead to poor clinical outcomes including treatment failure, development of bacteremia, requirement for intravenous therapy, hospitalization, and extended length of hospital stay. The mechanisms of drug resistance in these bacteria are important due to they are often not identified by routine susceptibility tests and have an exceptional potential for outbreaks. Treatment of UTIs depends on the access to effective drugs, which is now threatened by antibiotic resistant Gram-negative uropathogens. Although several effective antibiotics with activity against highly resistant Gram-negatives are available, there is not a unique antibiotic with activity against the high variety of resistance. Therefore, antimicrobial susceptibility tests, correlation between clinicians and laboratories, development of more rapid diagnostic methods, and continuous monitoring of drug resistance are urgent priorities. In this review, we will discuss about the current global status of drug-resistant Gram-negative uropathogens and their mechanisms of drug resistance to provide new insights into their treatment options. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  5. Epidemic microclusters of blood-culture proven sepsis in very-low-birth weight infants: experience of the German Neonatal Network.

    Science.gov (United States)

    Härtel, Christoph; Faust, Kirstin; Avenarius, Stefan; Bohnhorst, Bettina; Emeis, Michael; Gebauer, Corinna; Groneck, Peter; Heitmann, Friedhelm; Hoehn, Thomas; Hubert, Mechthild; Kribs, Angela; Küster, Helmut; Laux, Reinhard; Mögel, Michael; Müller, Dirk; Olbertz, Dirk; Roll, Claudia; Siegel, Jens; Stein, Anja; Vochem, Matthias; Weller, Ursula; von der Wense, Axel; Wieg, Christian; Wintgens, Jürgen; Hemmelmann, Claudia; Simon, Arne; Herting, Egbert; Göpel, Wolfgang

    2012-01-01

    We evaluated blood culture-proven sepsis episodes occurring in microclusters in very-low-birth-weight infants born in the German Neonatal Network (GNN) during 2009-2010. Thirty-seven centers participated in GNN; 23 centers enrolled ≥50 VLBW infants in the study period. Data quality was approved by on-site monitoring. Microclusters of sepsis were defined as occurrence of at least two blood-culture proven sepsis events in different patients of one center within 3 months with the same bacterial species. For microcluster analysis, we selected sepsis episodes with typically cross-transmitted bacteria of high clinical significance including gram-negative rods and Enterococcus spp. In our cohort, 12/2110 (0.6%) infants were documented with an early-onset sepsis and 235 late-onset sepsis episodes (≥72 h of age) occurred in 203/2110 (9.6%) VLBW infants. In 182/235 (77.4%) late-onset sepsis episodes gram-positive bacteria were documented, while coagulase negative staphylococci were found to be the most predominant pathogens (48.5%, 95%CI: 42.01-55.01). Candida spp. and gram-negative bacilli caused 10/235 (4.3%, 95%CI: 1.68% -6.83%) and 43/235 (18.5%) late-onset sepsis episodes, respectively. Eleven microclusters of blood-culture proven sepsis were detected in 7 hospitals involving a total 26 infants. 16/26 cluster patients suffered from Klebsiella spp. sepsis. The median time interval between the first patient's Klebsiella spp. sepsis and cluster cases was 14.1 days (interquartile range: 1-27 days). First patients in the cluster, their linked cases and sporadic sepsis events did not show significant differences in short term outcome parameters. Microclusters of infection are an important phenomenon for late-onset sepsis. Most gram-negative cluster infections occur within 30 days after the first patient was diagnosed and Klebsiella spp. play a major role. It is essential to monitor epidemic microclusters of sepsis in surveillance networks to adapt clinical practice

  6. Neutrophil extracellular traps in the host defense against sepsis induced by Burkholderia pseudomallei (melioidosis)

    NARCIS (Netherlands)

    de Jong, Hanna K.; Koh, Gavin C. K. W.; Achouiti, Ahmed; van der Meer, Anne J.; Bulder, Ingrid; Stephan, Femke; Roelofs, Joris J. T. H.; Day, Nick P. J.; Peacock, Sharon J.; Zeerleder, Sacha; Wiersinga, W. Joost

    2014-01-01

    Neutrophil extracellular traps (NETs) are a central player in the host response to bacteria: neutrophils release extracellular DNA (nucleosomes) and neutrophil elastase to entrap and kill bacteria. We studied the role of NETs in Burkholderia pseudomallei infection (melioidosis), an important cause

  7. Endotoxin dosage in sepsis

    Directory of Open Access Journals (Sweden)

    Vincenzo Rondinelli

    2012-03-01

    Full Text Available Introduction. Endotoxin, a component of the cell wall of Gram-negative bacteria is a major contributor to the pathogenesis of septic shock and multiple organ failure (MOF. Its entry into the bloodstream stimulates monocytes/macrophages which once activated produce and release cytokines, nitric oxide and other mediators that induce systemic inflammation, endothelial damage, organ dysfunction, hypotension (shock and MOF.The aim of this study is to evaluate the usefulness of a quantitative test for the dosage of endotoxin to determine the risk of severe Gram-negative sepsis. Materials and methods. In the period January 2009 - June 2011 we performed 897 tests for 765 patients, mostly coming from the emergency room and intensive care, of which 328 (43% women (mean age 53 and 437 (57% male (mean age 49. Fifty-nine patients, no statistically significant difference in sex, were monitored by an average of two determinations of EA.All patients had procalcitonin values significantly altered.The kit used was EAA (Endotoxin Activity Assay Estor Company, Milan, which has three ranges of endotoxin activity (EA: low risk of sepsis if <0.40 units, medium if between 0.40 and 0.59; high if 0.60. Results. 78 out of 765 patients (10% had a low risk, 447 (58% a medium risk and 240 (32% a high risk.The dosage of EA, combined with that of procalcitonin, has allowed a more targeted antibiotic therapy. Six patients in serious clinical conditions were treated by direct hemoperfusion with Toraymyxin, a device comprising a housing containing a fiber polypropylene and polystyrene with surface-bound polymyxin B, an antibiotic that removes bacterial endotoxins from the blood. Conclusions.The test is useful in risk stratification as well as Gram negative sepsis, to set and monitor targeted therapies, also based on the neutralization of endotoxin.

  8. Emergence of Melioidosis in Indonesia.

    Science.gov (United States)

    Tauran, Patricia M; Sennang, Nurhayana; Rusli, Benny; Wiersinga, W Joost; Dance, David; Arif, Mansyur; Limmathurotsakul, Direk

    2015-12-01

    Melioidosis is known to be highly endemic in parts of southeast Asia and northern Australia; however, cases are rarely reported in Indonesia. Here we report three cases of melioidosis in Makassar, South Sulawesi, Indonesia occurring between 2013 and 2014. Two patients died and the other was lost to follow-up. Burkholderia pseudomallei isolates from all three cases were identified by the VITEK2 Compact installed in the hospital in 2012. None of the three patients reported received antimicrobials recommended for melioidosis because of the delayed recognition of the organism. We reviewed the literature and found only seven reports of melioidosis in Indonesia. Five were reported before 1960. We suggest that melioidosis is endemic throughout Indonesia but currently under-recognized. Training on how to identify B. pseudomallei accurately and safely in all available microbiological facilities should be provided, and consideration should be given to making melioidosis a notifiable disease in Indonesia. © The American Society of Tropical Medicine and Hygiene.

  9. Melioidosis Cases and Selected Reports of Occupational Exposures to Burkholderia pseudomallei--United States, 2008-2013.

    Science.gov (United States)

    Benoit, Tina J; Blaney, David D; Gee, Jay E; Elrod, Mindy G; Hoffmaster, Alex R; Doker, Thomas J; Bower, William A; Walke, Henry T

    2015-07-03

    Melioidosis is an infection caused by the Gram-negative bacillus Burkholderia pseudomallei, which is naturally found in water and soil in areas endemic for melioidosis. Infection can be severe and sometimes fatal. The federal select agent program designates B. pseudomallei as a Tier 1 overlap select agent, which can affect both humans and animals. Identification of B. pseudomallei and all occupational exposures must be reported to the Federal Select Agent Program immediately (i.e., within 24 hours), whereas states are not required to notify CDC's Bacterial Special Pathogens Branch (BSPB) of human infections. 2008-2013. The passive surveillance system includes reports of suspected (human and animal) melioidosis cases and reports of incidents of possible occupational exposures. Reporting of suspected cases to BSPB is voluntary. BSPB receives reports of occupational exposure in the context of a request for technical consultation (so that the system does not include the full complement of the mandatory and confidential reporting to the Federal Select Agent Program). Reporting sources include state health departments, medical facilities, microbiologic laboratories, or research facilities. Melioidosis cases are classified using the standard case definition adopted by the Council of State and Territorial Epidemiologists in 2011. In follow up to reports of occupational exposures, CDC often provides technical assistance to state health departments to identify all persons with possible exposures, define level of risk, and provide recommendations for postexposure prophylaxis and health monitoring of exposed persons. During 2008-2013, BSPB provided technical assistance to 20 U.S. states and Puerto Rico involving 37 confirmed cases of melioidosis (34 human cases and three animal cases). Among those with documented travel history, the majority of reported cases (64%) occurred among persons with a documented travel history to areas endemic for melioidosis. Two persons did not

  10. Gram positive and Gram negative bacteria differ in their sensitivity to cold plasma

    Science.gov (United States)

    Mai-Prochnow, Anne; Clauson, Maryse; Hong, Jungmi; Murphy, Anthony B.

    2016-12-01

    Cold atmospheric-pressure plasma (CAP) is a relatively new method being investigated for antimicrobial activity. However, the exact mode of action is still being explored. Here we report that CAP efficacy is directly correlated to bacterial cell wall thickness in several species. Biofilms of Gram positive Bacillus subtilis, possessing a 55.4 nm cell wall, showed the highest resistance to CAP, with less than one log10 reduction after 10 min treatment. In contrast, biofilms of Gram negative Pseudomonas aeruginosa, possessing only a 2.4 nm cell wall, were almost completely eradicated using the same treatment conditions. Planktonic cultures of Gram negative Pseudomonas libanensis also had a higher log10 reduction than Gram positive Staphylococcus epidermidis. Mixed species biofilms of P. aeruginosa and S. epidermidis showed a similar trend of Gram positive bacteria being more resistant to CAP treatment. However, when grown in co-culture, Gram negative P. aeruginosa was more resistant to CAP overall than as a mono-species biofilm. Emission spectra indicated OH and O, capable of structural cell wall bond breakage, were present in the plasma. This study indicates that cell wall thickness correlates with CAP inactivation times of bacteria, but cell membranes and biofilm matrix are also likely to play a role.

  11. Melioidosis in Malaysia: A Review of Case Reports.

    Science.gov (United States)

    Kingsley, Paul Vijay; Leader, Mark; Nagodawithana, Nandika Suranjith; Tipre, Meghan; Sathiakumar, Nalini

    2016-12-01

    Melioidosis is a tropical infectious disease associated with significant mortality due to early onset of sepsis. We sought to review case reports of melioidosis from Malaysia. We conducted a computerized search of literature resources including PubMed, OVID, Scopus, MEDLINE and the COCHRANE database to identify published case reports from 1975 to 2015. We abstracted information on clinical characteristics, exposure history, comorbid conditions, management and outcome. Overall, 67 cases were reported with 29 (43%) deaths; the median age was 44 years, and a male preponderance (84%) was noted. Forty-one cases (61%) were bacteremic, and fatal septic shock occurred in 13 (19%) within 24-48 hours of admission; nine of the 13 cases were not specifically treated for melioidosis as confirmatory evidence was available only after death. Diabetes mellitus (n = 36, 54%) was the most common risk factor. Twenty-six cases (39%) had a history of exposure to contaminated soil/water or employment in high-risk occupations. Pneumonia (n = 24, 36%) was the most common primary clinical presentation followed by soft tissue abscess (n = 22, 33%). Other types of clinical presentations were less common-genitourinary (n = 5), neurological (n = 5), osteomyelitis/septic arthritis (n = 4) and skin (n = 2); five cases had no evidence of a focus of infection. With regard to internal foci of infection, abscesses of the subcutaneous tissue (n = 14, 21%) was the most common followed by liver (18%); abscesses of the spleen and lung were the third most common (12% each). Seven of 56 males were reported to have prostatic abscesses. Mycotic pseudoaneurysm occurred in five cases. Only one case of parotid abscess was reported in an adult. Of the 67 cases, 13 were children (≤ 18 years of age) with seven deaths; five of the 13 were neonates presenting primarily with bronchopneumonia, four of whom died. Older children had a similar presentation as adults; no case of parotid abscess was reported among

  12. Melioidosis in Malaysia: A Review of Case Reports

    Science.gov (United States)

    Kingsley, Paul Vijay; Leader, Mark; Nagodawithana, Nandika Suranjith; Tipre, Meghan; Sathiakumar, Nalini

    2016-01-01

    Background Melioidosis is a tropical infectious disease associated with significant mortality due to early onset of sepsis. Objective We sought to review case reports of melioidosis from Malaysia. Methods We conducted a computerized search of literature resources including PubMed, OVID, Scopus, MEDLINE and the COCHRANE database to identify published case reports from 1975 to 2015. We abstracted information on clinical characteristics, exposure history, comorbid conditions, management and outcome. Results Overall, 67 cases were reported with 29 (43%) deaths; the median age was 44 years, and a male preponderance (84%) was noted. Forty-one cases (61%) were bacteremic, and fatal septic shock occurred in 13 (19%) within 24–48 hours of admission; nine of the 13 cases were not specifically treated for melioidosis as confirmatory evidence was available only after death. Diabetes mellitus (n = 36, 54%) was the most common risk factor. Twenty-six cases (39%) had a history of exposure to contaminated soil/water or employment in high-risk occupations. Pneumonia (n = 24, 36%) was the most common primary clinical presentation followed by soft tissue abscess (n = 22, 33%). Other types of clinical presentations were less common—genitourinary (n = 5), neurological (n = 5), osteomyelitis/septic arthritis (n = 4) and skin (n = 2); five cases had no evidence of a focus of infection. With regard to internal foci of infection, abscesses of the subcutaneous tissue (n = 14, 21%) was the most common followed by liver (18%); abscesses of the spleen and lung were the third most common (12% each). Seven of 56 males were reported to have prostatic abscesses. Mycotic pseudoaneurysm occurred in five cases. Only one case of parotid abscess was reported in an adult. Of the 67 cases, 13 were children (≤ 18 years of age) with seven deaths; five of the 13 were neonates presenting primarily with bronchopneumonia, four of whom died. Older children had a similar presentation as adults; no case of

  13. Melioidosis in Malaysia: A Review of Case Reports.

    Directory of Open Access Journals (Sweden)

    Paul Vijay Kingsley

    2016-12-01

    Full Text Available Melioidosis is a tropical infectious disease associated with significant mortality due to early onset of sepsis.We sought to review case reports of melioidosis from Malaysia.We conducted a computerized search of literature resources including PubMed, OVID, Scopus, MEDLINE and the COCHRANE database to identify published case reports from 1975 to 2015. We abstracted information on clinical characteristics, exposure history, comorbid conditions, management and outcome.Overall, 67 cases were reported with 29 (43% deaths; the median age was 44 years, and a male preponderance (84% was noted. Forty-one cases (61% were bacteremic, and fatal septic shock occurred in 13 (19% within 24-48 hours of admission; nine of the 13 cases were not specifically treated for melioidosis as confirmatory evidence was available only after death. Diabetes mellitus (n = 36, 54% was the most common risk factor. Twenty-six cases (39% had a history of exposure to contaminated soil/water or employment in high-risk occupations. Pneumonia (n = 24, 36% was the most common primary clinical presentation followed by soft tissue abscess (n = 22, 33%. Other types of clinical presentations were less common-genitourinary (n = 5, neurological (n = 5, osteomyelitis/septic arthritis (n = 4 and skin (n = 2; five cases had no evidence of a focus of infection. With regard to internal foci of infection, abscesses of the subcutaneous tissue (n = 14, 21% was the most common followed by liver (18%; abscesses of the spleen and lung were the third most common (12% each. Seven of 56 males were reported to have prostatic abscesses. Mycotic pseudoaneurysm occurred in five cases. Only one case of parotid abscess was reported in an adult. Of the 67 cases, 13 were children (≤ 18 years of age with seven deaths; five of the 13 were neonates presenting primarily with bronchopneumonia, four of whom died. Older children had a similar presentation as adults; no case of parotid abscess was reported among

  14. Veillonella, Firmicutes: Microbes disguised as Gram negatives.

    Science.gov (United States)

    Vesth, Tammi; Ozen, Aslı; Andersen, Sandra C; Kaas, Rolf Sommer; Lukjancenko, Oksana; Bohlin, Jon; Nookaew, Intawat; Wassenaar, Trudy M; Ussery, David W

    2013-12-20

    The Firmicutes represent a major component of the intestinal microflora. The intestinal Firmicutes are a large, diverse group of organisms, many of which are poorly characterized due to their anaerobic growth requirements. Although most Firmicutes are Gram positive, members of the class Negativicutes, including the genus Veillonella, stain Gram negative. Veillonella are among the most abundant organisms of the oral and intestinal microflora of animals and humans, in spite of being strict anaerobes. In this work, the genomes of 24 Negativicutes, including eight Veillonella spp., are compared to 20 other Firmicutes genomes; a further 101 prokaryotic genomes were included, covering 26 phyla. Thus a total of 145 prokaryotic genomes were analyzed by various methods to investigate the apparent conflict of the Veillonella Gram stain and their taxonomic position within the Firmicutes. Comparison of the genome sequences confirms that the Negativicutes are distantly related to Clostridium spp., based on 16S rRNA, complete genomic DNA sequences, and a consensus tree based on conserved proteins. The genus Veillonella is relatively homogeneous: inter-genus pair-wise comparison identifies at least 1,350 shared proteins, although less than half of these are found in any given Clostridium genome. Only 27 proteins are found conserved in all analyzed prokaryote genomes. Veillonella has distinct metabolic properties, and significant similarities to genomes of Proteobacteria are not detected, with the exception of a shared LPS biosynthesis pathway. The clade within the class Negativicutes to which the genus Veillonella belongs exhibits unique properties, most of which are in common with Gram-positives and some with Gram negatives. They are only distantly related to Clostridia, but are even less closely related to Gram-negative species. Though the Negativicutes stain Gram-negative and possess two membranes, the genome and proteome analysis presented here confirm their place within the

  15. Revisiting the Gram-negative lipoprotein paradigm.

    Science.gov (United States)

    LoVullo, Eric D; Wright, Lori F; Isabella, Vincent; Huntley, Jason F; Pavelka, Martin S

    2015-05-01

    The processing of lipoproteins (Lpps) in Gram-negative bacteria is generally considered an essential pathway. Mature lipoproteins in these bacteria are triacylated, with the final fatty acid addition performed by Lnt, an apolipoprotein N-acyltransferase. The mature lipoproteins are then sorted by the Lol system, with most Lpps inserted into the outer membrane (OM). We demonstrate here that the lnt gene is not essential to the Gram-negative pathogen Francisella tularensis subsp. tularensis strain Schu or to the live vaccine strain LVS. An LVS Δlnt mutant has a small-colony phenotype on sucrose medium and increased susceptibility to globomycin and rifampin. We provide data indicating that the OM lipoprotein Tul4A (LpnA) is diacylated but that it, and its paralog Tul4B (LpnB), still sort to the OM in the Δlnt mutant. We present a model in which the Lol sorting pathway of Francisella has a modified ABC transporter system that is capable of recognizing and sorting both triacylated and diacylated lipoproteins, and we show that this modified system is present in many other Gram-negative bacteria. We examined this model using Neisseria gonorrhoeae, which has the same Lol architecture as that of Francisella, and found that the lnt gene is not essential in this organism. This work suggests that Gram-negative bacteria fall into two groups, one in which full lipoprotein processing is essential and one in which the final acylation step is not essential, potentially due to the ability of the Lol sorting pathway in these bacteria to sort immature apolipoproteins to the OM. This paper describes the novel finding that the final stage in lipoprotein processing (normally considered an essential process) is not required by Francisella tularensis or Neisseria gonorrhoeae. The paper provides a potential reason for this and shows that it may be widespread in other Gram-negative bacteria. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  16. Silver enhances antibiotic activity against gram-negative bacteria.

    Science.gov (United States)

    Morones-Ramirez, J Ruben; Winkler, Jonathan A; Spina, Catherine S; Collins, James J

    2013-06-19

    A declining pipeline of clinically useful antibiotics has made it imperative to develop more effective antimicrobial therapies, particularly against difficult-to-treat Gram-negative pathogens. Silver has been used as an antimicrobial since antiquity, yet its mechanism of action remains unclear. We show that silver disrupts multiple bacterial cellular processes, including disulfide bond formation, metabolism, and iron homeostasis. These changes lead to increased production of reactive oxygen species and increased membrane permeability of Gram-negative bacteria that can potentiate the activity of a broad range of antibiotics against Gram-negative bacteria in different metabolic states, as well as restore antibiotic susceptibility to a resistant bacterial strain. We show both in vitro and in a mouse model of urinary tract infection that the ability of silver to induce oxidative stress can be harnessed to potentiate antibiotic activity. Additionally, we demonstrate in vitro and in two different mouse models of peritonitis that silver sensitizes Gram-negative bacteria to the Gram-positive-specific antibiotic vancomycin, thereby expanding the antibacterial spectrum of this drug. Finally, we used silver and antibiotic combinations in vitro to eradicate bacterial persister cells, and show both in vitro and in a mouse biofilm infection model that silver can enhance antibacterial action against bacteria that produce biofilms. This work shows that silver can be used to enhance the action of existing antibiotics against Gram-negative bacteria, thus strengthening the antibiotic arsenal for fighting bacterial infections.

  17. Melioidosis in Thailand: Present and Future

    Directory of Open Access Journals (Sweden)

    Soawapak Hinjoy

    2018-04-01

    Full Text Available A recent modelling study estimated that there are 2800 deaths due to melioidosis in Thailand yearly. The Thailand Melioidosis Network (formed in 2012 has been working closely with the Ministry of Public Health (MoPH to investigate and reduce the burden of this disease. Based on updated data, the incidence of melioidosis is still high in Northeast Thailand. More than 2000 culture-confirmed cases of melioidosis are diagnosed in general hospitals with microbiology laboratories in this region each year. The mortality rate is around 35%. Melioidosis is endemic throughout Thailand, but it is still not uncommon that microbiological facilities misidentify Burkholderia pseudomallei as a contaminant or another organism. Disease awareness is low, and people in rural areas neither wear boots nor boil water before drinking to protect themselves from acquiring B. pseudomallei. Previously, about 10 melioidosis deaths were formally reported to the National Notifiable Disease Surveillance System (Report 506 each year, thus limiting priority setting by the MoPH. In 2015, the formally reported number of melioidosis deaths rose to 112, solely because Sunpasithiprasong Hospital, Ubon Ratchathani province, reported its own data (n = 107. Melioidosis is truly an important cause of death in Thailand, and currently reported cases (Report 506 and cases diagnosed at research centers reflect the tip of the iceberg. Laboratory training and communication between clinicians and laboratory personnel are required to improve diagnosis and treatment of melioidosis countrywide. Implementation of rapid diagnostic tests, such as a lateral flow antigen detection assay, with high accuracy even in melioidosis-endemic countries such as Thailand, is critically needed. Reporting of all culture-confirmed melioidosis cases from every hospital with a microbiology laboratory, together with final outcome data, is mandated under the Communicable Diseases Act B.E.2558. By enforcing this

  18. Mid-infrared spectroscopic assessment of nanotoxicity in gram-negative vs. gram-positive bacteria.

    Science.gov (United States)

    Heys, Kelly A; Riding, Matthew J; Strong, Rebecca J; Shore, Richard F; Pereira, M Glória; Jones, Kevin C; Semple, Kirk T; Martin, Francis L

    2014-03-07

    Nanoparticles appear to induce toxic effects through a variety of mechanisms including generation of reactive oxygen species (ROS), physical contact with the cell membrane and indirect catalysis due to remnants from manufacture. The development and subsequent increasing usage of nanomaterials has highlighted a growing need to characterize and assess the toxicity of nanoparticles, particularly those that may have detrimental health effects such as carbon-based nanomaterials (CBNs). Due to interactions of nanoparticles with some reagents, many traditional toxicity tests are unsuitable for use with CBNs. Infrared (IR) spectroscopy is a non-destructive, high throughput technique, which is unhindered by such problems. We explored the application of IR spectroscopy to investigate the effects of CBNs on Gram-negative (Pseudomonas fluorescens) and Gram-positive (Mycobacterium vanbaalenii PYR-1) bacteria. Two types of IR spectroscopy were compared: attenuated total reflection Fourier-transform infrared (ATR-FTIR) and synchrotron radiation-based FTIR (SR-FTIR) spectroscopy. This showed that Gram-positive and Gram-negative bacteria exhibit differing alterations when exposed to CBNs. Gram-positive bacteria appear more resistant to these agents and this may be due to the protection afforded by their more sturdy cell wall. Markers of exposure also vary according to Gram status; Amide II was consistently altered in Gram-negative bacteria and carbohydrate altered in Gram-positive bacteria. ATR-FTIR and SR-FTIR spectroscopy could both be applied to extract biochemical alterations induced by each CBN that were consistent across the two bacterial species; these may represent potential biomarkers of nanoparticle-induced alterations. Vibrational spectroscopy approaches may provide a novel means of fingerprinting the effects of CBNs in target cells.

  19. Acute Disseminated Melioidosis Presenting with Septic Arthritis and Diffuse Pulmonary Consolidation in an Otherwise Healthy Adult: A Case Report

    Directory of Open Access Journals (Sweden)

    Hai Sherng Lee

    2015-03-01

    Full Text Available Background: Melioidosis is an infectious disease caused by Burkholderia pseudomallei. It is most prevalent in South-East Asia, northern Australia, and the Indian subcontinent. Septic arthritis is a rare manifestation of melioidosis. Melioidosis is usually found in patients with diabetes, heavy alcohol use, or chronic lung disease. Results: We report a case of melioidosis in an otherwise healthy 44-year-old male, who presented with acute painful left knee swelling, high-grade fever associated with chills, rigors and night sweats, and a productive cough. Examination revealed active synovitis with effusion involving his left knee, ankle and elbow joints and scattered crackles over both lung fields. Chest X-ray showed diffuse pulmonary consolidation. Abdominal ultrasound showed splenic micro-abscesses. The diagnosis was made based on a positive blood culture for Burkholderia pseudomallei. He was started on appropriate antibiotics and responded well, becoming afebrile after 48 hours, while his joint effusions disappeared after one week. A repeat chest X-ray after two weeks of intensive antibiotic therapy showed marked improvement. At the time of writing, he was under uneventful outpatient follow-up and still had 12 weeks to complete his course of antibiotics. Conclusion: Septic arthritis only occurs in 4% of patients with melioidosis. When there is diffuse pulmonary involvement, melioidosis may mimic disseminated tuberculosis, other acute disseminated or focal sepsis syndromes, and systemic vasculitis syndromes. This case is relevant for medical literature as melioidosis is emerging and is expanding its known territories worldwide. It should be considered early in the differential diagnoses of patients presenting with constitutional symptoms in endemic areas, so that treatment can be started early to reduce its high mortality and morbidity.

  20. Sulphonylurea usage in melioidosis is associated with severe disease and suppressed immune response.

    Directory of Open Access Journals (Sweden)

    Xiang Liu

    2014-04-01

    Full Text Available BACKGROUND: Melioidosis is a problem in the developing tropical regions of Southeast Asia and Northern Australia where the the Gram negative saprophytic bacillus Burkholderia pseudomallei is endemic with the risk of fulminant septicaemia. While diabetes mellitus is a well-established risk factor for melioidiosis, little is known if specific hypoglycemic agents may differentially influence the susceptibility and clinical course of infection with B. pseudomallei (Bp. METHODOLOGY/PRINCIPAL FINDINGS: In this cohort study, patients with pre-existing diabetes and melioidosis were retrospectively studied. OUTCOME MEASURES: mortality, length of stay and development of complications (namely hypotension, intubation, renal failure and septicaemia were studied in relation to prior diabetic treatment regimen. Peripheral blood mononuclear cells (PBMC from diabetic patients and healthy PBMC primed with metformin, glyburide and insulin were stimulated with purified Bp antigens in vitro. Immune response and specific immune pathway mediators were studied to relate to the clinical findings mechanistically. Of 74 subjects, 44 (57.9% had sulphonylurea-containing diabetic regimens. Patient receiving sulphonylureas had more severe septic complications (47.7% versus 16.7% p = 0.006, in particular, hypotension requiring intropes (p = 0.005. There was also a trend towards increased mortality in sulphonylurea-users (15.9% versus 3.3% p = 0.08. In-vitro, glyburide suppressed inflammatory cytokine production in a dose-dependent manner. An effect of the drug was the induction of IL-1R-associated kinase-M at the level of mRNA transcription. CONCLUSION/SIGNIFICANCE: Sulphonylurea treatment results in suppression of host inflammatory response and may put patients at higher risk for adverse outcomes in melioidosis.

  1. Procalcitonin levels in patients with positive blood culture, positive body fluid culture, sepsis, and severe sepsis: a cross-sectional study.

    Science.gov (United States)

    Yu, Ying; Li, Xia-Xi; Jiang, Ling-Xiao; Du, Meng; Liu, Zhan-Guo; Cen, Zhong-Ran; Wang, Hua; Guo, Zhen-Hui; Chang, Ping

    2016-01-01

    Numerous investigations on procalcitonin (PCT) have been carried out, although few with large sample size. To deal with the complexity of sepsis, an understanding of PCT in heterogeneous clinical conditions is required. Hospitalized patients aged 10-79 years were included in this retrospective and cross-sectional study. PCT tests were assayed within 2 days of blood culture. A total of 2952 cases (from 2538 patients) were enrolled in this study, including 440 cases in the 'positive BC' group, 123 cases in the 'positive body fluid culture' group, and 2389 cases in the 'negative all culture' group. Median PCT values were 4.53 ng/ml, 2.95 ng/ml, and 0.49 ng/ml, respectively. Median PCT values in the gram-negative BC group and gram-positive BC group, respectively, were 6.99 ng/ml and 2.96 ng/ml. Median PCT values in the 'positive hydrothorax culture' group, 'positive ascites culture' group, 'positive bile culture' group, and 'positive cerebrospinal fluid culture' group, respectively, were 1.39 ng/ml, 8.32 ng/ml, 5.98 ng/ml, and 0.46 ng/ml. In all, 357 cases were classified into the 'sepsis' group, 150 of them were classified into the 'severe sepsis' group. Median PCT values were 5.63 ng/ml and 11.06 ng/ml, respectively. PCT could be used in clinical algorithms to diagnose positive infections and sepsis. Different PCT levels could be related to different kinds of microbemia, different infection sites, and differing severity of sepsis.

  2. Analysis of neonatal sepsis in one neonatal intensive care unit for 6 years

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    Peter Chun

    2010-04-01

    Full Text Available Purpose : Sepsis is a significant cause of morbidity and mortality in the newborn, particularly in preterm. The objective of this study was to analyze the incidence rate, causative pathogens and clinical features of neonatal sepsis in one neonatal intensive care unit (NICU for 6 years. Methods : This study was retrospectively performed to review the clinical and laboratory characteristics including sex, gestational age, birth weight, Apgar score, length of hospitalization, length of total parenteral nutrition, presence of central venous catheter, underlying diseases, laboratory findings, microorganisms isolated from blood culture, complications and mortality in 175 patients between January 2003 and December 2008. Results : 1 Sepsis was present in 175 of 3,747 infants for 6 years. There were more gram-positive organisms. 2 The gram-negatives were more prevalent in preterm. There were no significant differences of other clinical features between two groups. 3 Underlying diseases were found in 73.7%, and the most common disease was cardiovascular disease. The most common organisms of gram-positives and gram-negatives were methicillin resistant Staphylococcus aureus (MRSA and Serratia marcescens. 4 There was statistically significant difference on platelet counts between two groups (P&lt;0.05. 5 Complications were found in 18.3% and septic shock was the most common. MRSA was the most common pathogen in sepsis with complication. 6 The mortality rate was 7.4%. 7 There were differences in monthly blood stream infection/ 1,000 patient-days. Conclusion : The studies about the factors that can influence neonatal sepsis will contribute to decrease the infection rates in NICUs.

  3. Melioidosis: An emerging infectious disease

    Directory of Open Access Journals (Sweden)

    Raja N

    2005-01-01

    Full Text Available Infectious diseases account for a third of all the deaths in the developing world. Achievements in understanding the basic microbiology, pathogenesis, host defenses and expanded epidemiology of infectious diseases have resulted in better management and reduced mortality. However, an emerging infectious disease, melioidosis, is becoming endemic in the tropical regions of the world and is spreading to non-endemic areas. This article highlights the current understanding of melioidosis including advances in diagnosis, treatment and prevention. Better understanding of melioidosis is essential, as it is life-threatening and if untreated, patients can succumb to it. Our sources include a literature review, information from international consensus meetings on melioidosis and ongoing discussions within the medical and scientific community.

  4. Pulmonary infiltrates during community acquired Gram-negative bacteremia

    DEFF Research Database (Denmark)

    Fjeldsøe-Nielsen, Hans; Gjeraa, Kirsten; Berthelsen, Birgitte G

    2013-01-01

    The primary aim of this study was to describe the frequency of pulmonary infiltrates on chest X-ray (CXR) during community acquired Gram-negative bacteremia at a single centre in Denmark.......The primary aim of this study was to describe the frequency of pulmonary infiltrates on chest X-ray (CXR) during community acquired Gram-negative bacteremia at a single centre in Denmark....

  5. Comparative activity of ceftobiprole against Gram-positive and Gram-negative isolates from Europe and the Middle East: the CLASS study.

    Science.gov (United States)

    Rossolini, Gian M; Dryden, Matthew S; Kozlov, Roman S; Quintana, Alvaro; Flamm, Robert K; Läuffer, Jörg M; Lee, Emma; Morrissey, Ian; CLASS Study Group

    2011-01-01

    to assess the in vitro activity of ceftobiprole and comparators against a recent collection of Gram-positive and Gram-negative pathogens, in order to detect potential changes in susceptibility patterns, and to evaluate the Etest assay for ceftobiprole susceptibility testing. contemporary Gram-positive and Gram-negative isolates (excluding extended-spectrum β-lactamase-producing isolates) from across Europe and the Middle East were collected, and their susceptibility to ceftobiprole, vancomycin, teicoplanin, linezolid, ceftazidime and cefepime was assessed using the Etest method. Quality testing [using Etest and broth microdilution (BMD)] was conducted at a central reference laboratory. some 5041 Gram-positive and 4026 Gram-negative isolates were included. Against Gram-positive isolates overall, ceftobiprole had the lowest MIC50 (0.5 mg/L), compared with 1 mg/L for its comparators (vancomycin, teicoplanin and linezolid). Against methicillin-resistant Staphylococcus aureus, all four agents had a similar MIC90 (2 mg/L), but ceftobiprole had a 4-fold better MIC90 (0.5 mg/L) against methicillin-susceptible strains. Only 38 Gram-positive isolates were confirmed as ceftobiprole resistant. Among Gram-negative strains, 86.9%, 91.7% and 95.2% were susceptible to ceftobiprole, ceftazidime and cefepime, respectively. Pseudomonas aeruginosa was less susceptible to all three antimicrobials than any other Gram-negative pathogen. There was generally good agreement between local Etest results and those obtained at the reference laboratory (for ceftobiprole: 86.8% with Gram-negatives; and 94.7% with Gram-positives), as well as between results obtained by BMD and Etest methods (for ceftobiprole: 98.2% with Gram-negatives; and 98.4% with Gram-positives). ceftobiprole exhibits in vitro activity against a wide range of Gram-positive and Gram-negative pathogens, including multidrug-resistant strains. No changes in its known susceptibility profile were identified.

  6. Prediction of lipoprotein signal peptides in Gram-negative bacteria.

    Science.gov (United States)

    Juncker, Agnieszka S; Willenbrock, Hanni; Von Heijne, Gunnar; Brunak, Søren; Nielsen, Henrik; Krogh, Anders

    2003-08-01

    A method to predict lipoprotein signal peptides in Gram-negative Eubacteria, LipoP, has been developed. The hidden Markov model (HMM) was able to distinguish between lipoproteins (SPaseII-cleaved proteins), SPaseI-cleaved proteins, cytoplasmic proteins, and transmembrane proteins. This predictor was able to predict 96.8% of the lipoproteins correctly with only 0.3% false positives in a set of SPaseI-cleaved, cytoplasmic, and transmembrane proteins. The results obtained were significantly better than those of previously developed methods. Even though Gram-positive lipoprotein signal peptides differ from Gram-negatives, the HMM was able to identify 92.9% of the lipoproteins included in a Gram-positive test set. A genome search was carried out for 12 Gram-negative genomes and one Gram-positive genome. The results for Escherichia coli K12 were compared with new experimental data, and the predictions by the HMM agree well with the experimentally verified lipoproteins. A neural network-based predictor was developed for comparison, and it gave very similar results. LipoP is available as a Web server at www.cbs.dtu.dk/services/LipoP/.

  7. Protamine-induced permeabilization of cell envelopes of gram-positive and gram-negative bacteria

    DEFF Research Database (Denmark)

    Johansen, Charlotte; Verheul, A.; Gram, Lone

    1997-01-01

    carboxyfluorescein and ATP after 2 to 5 min. Maximum antibacterial activity was reached at alkaline pH and in the absence of divalent cations. The efficient permeabilization of cell envelopes of both gram-positive and gram-negative bacteria suggests that protamine causes a general disruption of the cell envelope...

  8. Retrospective Analysis of Blood Stream Infections and Antibiotic Susceptibility Pattern of Gram Negative Bacteria in a Tertiary Care Cancer Hospital

    Directory of Open Access Journals (Sweden)

    Radha Rani D

    2017-12-01

    Full Text Available Background: Bacterial bloodstream infections are important causes of morbidity and mortality globally. The aim of the present study was to determine the bacterial profile of bloodstream infections and their antibiotic susceptibility pattern among the clinically diagnosed cases of sepsis in cancer patients. Methods: In the present study, etiological and antimicrobial susceptibility profile of blood cultures over a period of 1 year at a tertiary cancer care hospital was done. Blood culture positive isolates were identified using standard microbiological methods and by Fully automated BD Phoenix 100. The antibiotic susceptibility pattern of the organisms was performed by Kirby-Bauer disc diffusion method and MIC (Minimum inhibitory concentration was done by Fully automated BD Phoenix 100. Results: There were 1178 blood culture samples, of which 327 (27.7% were identified to be culture positive. Out of 327 positive cultures, 299 (91.4% showed bacterial growth, Gram negative were 161 (53.8% and Gram positive were 138 (46.1%. Candida species were isolated from 13 (3.97% of positive samples and 15 samples showed contamination. The most common Gram-negative isolate was. Escherichia coli (37.80% and Gram-positive isolate was coagulasenegative staphylococci (52.80%. Escherichia coli showed highest sensitivity to amikacin (83.60% and sensitivity to piperacillin+ tazobactum and cefaperazone+sulbactam was 54.09% and 52.45% respectively. High degree of resistance was found to cephalosporins and levofloxacin. Conclusion: The results indicate high level of antimicrobial resistance among Gram negative bacilli in septicemic patients. The results warrant continuous monitoring of antimicrobial pattern so as to build geographical epidemiological data.

  9. An optimized staining technique for the detection of Gram positive and Gram negative bacteria within tissue.

    Science.gov (United States)

    Becerra, Sandra C; Roy, Daniel C; Sanchez, Carlos J; Christy, Robert J; Burmeister, David M

    2016-04-12

    Bacterial infections are a common clinical problem in both acute and chronic wounds. With growing concerns over antibiotic resistance, treatment of bacterial infections should only occur after positive diagnosis. Currently, diagnosis is delayed due to lengthy culturing methods which may also fail to identify the presence of bacteria. While newer costly bacterial identification methods are being explored, a simple and inexpensive diagnostic tool would aid in immediate and accurate treatments for bacterial infections. Histologically, hematoxylin and eosin (H&E) and Gram stains have been employed, but are far from optimal when analyzing tissue samples due to non-specific staining. The goal of the current study was to develop a modification of the Gram stain that enhances the contrast between bacteria and host tissue. A modified Gram stain was developed and tested as an alternative to Gram stain that improves the contrast between Gram positive bacteria, Gram negative bacteria and host tissue. Initially, clinically relevant strains of Pseudomonas aeruginosa and Staphylococcus aureus were visualized in vitro and in biopsies of infected, porcine burns using routine Gram stain, and immunohistochemistry techniques involving bacterial strain-specific fluorescent antibodies as validation tools. H&E and Gram stain of serial biopsy sections were then compared to a modification of the Gram stain incorporating a counterstain that highlights collagen found in tissue. The modified Gram stain clearly identified both Gram positive and Gram negative bacteria, and when compared to H&E or Gram stain alone provided excellent contrast between bacteria and non-viable burn eschar. Moreover, when applied to surgical biopsies from patients that underwent burn debridement this technique was able to clearly detect bacterial morphology within host tissue. We describe a modification of the Gram stain that provides improved contrast of Gram positive and Gram negative microorganisms within host

  10. Probing interaction of Gram-positive and Gram-negative bacterial cells with ZnO nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Aanchal; Bhargava, Richa; Poddar, Pankaj, E-mail: p.poddar@ncl.res.in

    2013-04-01

    In the present work, the physiological effects of the ZnO nanorods on the Gram positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Escherichia coli and Aerobacter aerogenes) bacterial cells have been studied. The analysis of bacterial growth curves for various concentrations of ZnO nanorods indicates that Gram positive and Gram negative bacterial cells show inhibition at concentrations of ∼ 64 and ∼ 256 μg/mL respectively. The marked difference in susceptibility towards nanorods was also validated by spread plate and disk diffusion methods. In addition, the scanning electron micrographs show a clear damage to the cells via changed morphology of the cells from rod to coccoid etc. The confocal optical microscopy images of these cells also demonstrate the reduction in live cell count in the presence of ZnO nanorods. These, results clearly indicate that the antibacterial activity of ZnO nanorods is higher towards Gram positive bacterium than Gram negative bacterium which indicates that the structure of the cell wall might play a major role in the interaction with nanostructured materials and shows high sensitivity to the particle concentration. Highlights: ► Effect of ZnO nanorods on the growth cycles of four bacterial strains. ► A relation has been established between growth rate of bacteria and concentration. ► Serious damage in the morphology of bacterial cells in the presence of ZnO nanorods. ► Microscopic studies to see the time dependent effect on bacterial cells.

  11. Epidemiology of Adult-population Sepsis in India: A Single Center 5 Year Experience.

    Science.gov (United States)

    Chatterjee, Sharmila; Bhattacharya, Mahuya; Todi, Subhash Kumar

    2017-09-01

    Sepsis is a major worldwide cause of morbidity and mortality. Most sepsis epidemiologic data are from the Western literature. Sparse data from India describe the epidemiology of infection rather than sepsis which is a host response to infection. This study describes the epidemiology of sepsis in the Intensive Care Unit (ICU) of an Indian tertiary care hospital. A prospective study conducted between June 2006 and May 2011. All consecutively admitted patients during the 5 year study >=18 years of age were included and data obtained from hospital in-patient records. Variables measured were the incidence of severe sepsis, ICU, hospital, and 28-day mortality, the median length of ICU stay, median Acute Physiology and Chronic Health Evaluation II (APACHE II) score, infection site, and microbial profile. There were 4711 admissions during the study with 282 (6.2%, 95% confidence interval 2.3, 13.1) admissions with severe sepsis. ICU mortality, hospital mortality, and 28-day mortality were 56%, 63.6%, and 62.8%, respectively. Predominant infection site was respiratory tract. The most common organisms were Gram-negative microbes. The most common microbe was Acinetobacter baumanni. Median APACHE II score on admission was 22 (interquartile range 16-28) and median length of ICU stay was 8 days. Severe sepsis attributable mortality was 85%. Severe sepsis is common in Indian ICUs and is mainly due to Gram-negative organisms. ICU mortality is high in this group and care is resource intensive due to increased length of stay.

  12. Antimicrobial Activity of Carbon Nanoparticles Isolated from Natural Sources against Pathogenic Gram-Negative and Gram-Positive Bacteria

    International Nuclear Information System (INIS)

    Varghese, S.; Jose, S.; Varghese, S.; Kuriakose, S.; Jose, S.

    2013-01-01

    This paper describes the isolation of carbon nanoparticles (CNPs) from kitchen soot, characterization of the CNPs by UV/visible spectroscopy, SEM and XRD, and their antimicrobial action. The antibacterial activity of the isolated carbon nanoparticles was tested against various pathogenic bacterial strains such as Gram-negative Proteus refrigere and Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus and Streptococcus haemolyticus. The inhibition zones were measured, and it was found that the carbon nanoparticles isolated from natural sources are active against these Gram-negative and Gram-positive bacterial strains

  13. Potential strategies for the eradication of multidrug-resistant Gram-negative bacterial infections.

    Science.gov (United States)

    Huwaitat, Rawan; McCloskey, Alice P; Gilmore, Brendan F; Laverty, Garry

    2016-07-01

    Antimicrobial resistance is one of the leading threats to society. The increasing burden of multidrug-resistant Gram-negative infection is particularly concerning as such bacteria are demonstrating resistance to nearly all currently licensed therapies. Various strategies have been hypothesized to treat multidrug-resistant Gram-negative infections including: targeting the Gram-negative outer membrane; neutralization of lipopolysaccharide; inhibition of bacterial efflux pumps and prevention of protein folding. Silver and silver nanoparticles, fusogenic liposomes and nanotubes are potential strategies for extending the activity of licensed, Gram-positive selective, antibiotics to Gram-negatives. This may serve as a strategy to fill the current void in pharmaceutical development in the short term. This review outlines the most promising strategies that could be implemented to solve the threat of multidrug-resistant Gram-negative infections.

  14. Macrophage migration inhibitory factor deficiency is associated with impaired killing of gram-negative bacteria by macrophages and increased susceptibility to Klebsiella pneumoniae sepsis.

    Science.gov (United States)

    Roger, Thierry; Delaloye, Julie; Chanson, Anne-Laure; Giddey, Marlyse; Le Roy, Didier; Calandra, Thierry

    2013-01-15

    The cytokine macrophage migration inhibitory factor (MIF) is an important component of the early proinflammatory response of the innate immune system. However, the antimicrobial defense mechanisms mediated by MIF remain fairly mysterious. In the present study, we examined whether MIF controls bacterial uptake and clearance by professional phagocytes, using wild-type and MIF-deficient macrophages. MIF deficiency did not affect bacterial phagocytosis, but it strongly impaired the killing of gram-negative bacteria by macrophages and host defenses against gram-negative bacterial infection, as shown by increased mortality in a Klebsiella pneumonia model. Consistent with MIF's regulatory role of Toll-like 4 expression in macrophages, MIF-deficient cells stimulated with lipopolysaccharide or Escherichia coli exhibited reduced nuclear factor κB activity and tumor necrosis factor (TNF) production. Addition of recombinant MIF or TNF corrected the killing defect of MIF-deficient macrophages. Together, these data show that MIF is a key mediator of host responses against gram-negative bacteria, acting in part via a modulation of bacterial killing by macrophages.

  15. Tracing melioidosis back to the source: using whole-genome sequencing to investigate an outbreak originating from a contaminated domestic water supply.

    Science.gov (United States)

    McRobb, Evan; Sarovich, Derek S; Price, Erin P; Kaestli, Mirjam; Mayo, Mark; Keim, Paul; Currie, Bart J

    2015-04-01

    Melioidosis, a disease of public health importance in Southeast Asia and northern Australia, is caused by the Gram-negative soil bacillus Burkholderia pseudomallei. Melioidosis is typically acquired through environmental exposure, and case clusters are rare, even in regions where the disease is endemic. B. pseudomallei is classed as a tier 1 select agent by the Centers for Disease Control and Prevention; from a biodefense perspective, source attribution is vital in an outbreak scenario to rule out a deliberate release. Two cases of melioidosis within a 3-month period at a residence in rural northern Australia prompted an investigation to determine the source of exposure. B. pseudomallei isolates from the property's groundwater supply matched the multilocus sequence type of the clinical isolates. Whole-genome sequencing confirmed the water supply as the probable source of infection in both cases, with the clinical isolates differing from the likely infecting environmental strain by just one single nucleotide polymorphism (SNP) each. For the first time, we report a phylogenetic analysis of genomewide insertion/deletion (indel) data, an approach conventionally viewed as problematic due to high mutation rates and homoplasy. Our whole-genome indel analysis was concordant with the SNP phylogeny, and these two combined data sets provided greater resolution and a better fit with our epidemiological chronology of events. Collectively, this investigation represents a highly accurate account of source attribution in a melioidosis outbreak and gives further insight into a frequently overlooked reservoir of B. pseudomallei. Our methods and findings have important implications for outbreak source tracing of this bacterium and other highly recombinogenic pathogens. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  16. Novel insights in preventing Gram-negative bacterial infection in cirrhotic patients: review on the effects of GM-CSF in maintaining homeostasis of the immune system.

    Science.gov (United States)

    Xu, Dong; Zhao, Manzhi; Song, Yuhu; Song, Jianxin; Huang, Yuancheng; Wang, Junshuai

    2015-01-01

    Cirrhotic patients with dysfunctional and/or low numbers of leukocytes are often infected with bacteria, especially Gram-negative bacteria, which is characterized by producing lipopolysaccharide (LPS). Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a pleiotropic cytokine that influences the production, maturation, function, and survival of various immune cells. In this paper, we reviewed not only Toll-like receptors 4 (TLR4) signaling pathway and its immunological effect, but also the specific stimulating function and autocrine performance of GM-CSF on hematopoietic cells, as well as the recent discovery of innate response activator-B cells in protection against microbial sepsis and the direct LPS-TLR4 signaling on hematopoiesis. Thus we concluded that GM-CSF might play important roles in preventing Gram-negative bacterial infections in cirrhotic patients through maintaining immune system functions and homeostasis.

  17. Emergence of Melioidosis in Indonesia and Today’s Challenges

    Directory of Open Access Journals (Sweden)

    Patricia M. Tauran

    2018-03-01

    Full Text Available A recent modeling study estimated that there could be as many as 20,000 human melioidosis cases per year in Indonesia, with around 10,000 potential deaths annually. Nonetheless, the true burden of melioidosis in Indonesia is still unknown. The Indonesia Melioidosis Network was formed during the first melioidosis workshop in 2017. Here, we reviewed 101 melioidosis cases (99 human and two animal cases previously reported and described an additional 45 human melioidosis cases. All 146 culture-confirmed cases were found in Sumatra (n = 15, Java (n = 104, Kalimantan (n = 15, Sulawesi (n = 11 and Nusa Tenggara (n = 1. Misidentification of Burkholderia pseudomallei was not uncommon, and most cases were only recently identified. We also evaluated clinical manifestations and outcome of recent culture-confirmed cases between 2012 and 2017 (n = 42. Overall, 15 (36% cases were children (age <15 years and 27 (64% were adults (age ≥15 years. The overall mortality was 43% (18/42. We conducted a survey and found that 57% (327/548 of healthcare workers had never heard of melioidosis. In conclusion, melioidosis is endemic throughout Indonesia and associated with high mortality. We propose that top priorities are increasing awareness of melioidosis amongst all healthcare workers, increasing the use of bacterial culture, and ensuring accurate identification of B. pseudomalleiand diagnosis of melioidosis.

  18. Will new antimicrobials overcome resistance among Gram-negatives?

    Science.gov (United States)

    Bassetti, Matteo; Ginocchio, Francesca; Mikulska, Małgorzata; Taramasso, Lucia; Giacobbe, Daniele Roberto

    2011-10-01

    The spread of resistance among Gram-positive and Gram-negative bacteria represents a growing challenge for the development of new antimicrobials. The pace of antibiotic drug development has slowed during the last decade and, especially for Gram-negatives, clinicians are facing a dramatic shortage in the availability of therapeutic options to face the emergency of the resistance problem throughout the world. In this alarming scenario, although there is a shortage of compounds reaching the market in the near future, antibiotic discovery remains one of the keys to successfully stem and maybe overcome the tide of resistance. Analogs of already known compounds and new agents belonging to completely new classes of antimicrobials are in early stages of development. Novel and promising anti-Gram-negative antimicrobials belong both to old (cephalosporins, carbapenems, β-lactamase inhibitors, monobactams, aminoglycosides, polymyxin analogues and tetracycline) and completely new antibacterial classes (boron-containing antibacterial protein synthesis inhibitors, bis-indoles, outer membrane synthesis inhibitors, antibiotics targeting novel sites of the 50S ribosomal subunit and antimicrobial peptides). However, all of these compounds are still far from being introduced into clinical practice. Therefore, infection control policies and optimization in the use of already existing molecules are still the most effective approaches to reduce the spread of resistance and preserve the activity of antimicrobials.

  19. Revisiting the gram-negative lipoprotein paradigm

    Science.gov (United States)

    The processing of lipoproteins (lpps) in Gram-negative bacteria is generally considered to be an essential pathway. Mature lipoproteins in these bacteria are triacylated, with the final fatty acid addition performed by Lnt, an apolipoprotein n-acyltransferase. The mature lipoproteins are then sorted...

  20. Effect of sepsis on VLDL kinetics: responses in basal state and during glucose infusion

    International Nuclear Information System (INIS)

    Wolfe, R.R.; Shaw, J.H.; Durkot, M.J.

    1985-01-01

    The effect of gram-negative sepsis on the kinetics and oxidation of very low-density lipoprotein (VLDL) fatty acids was assessed in conscious dogs in the normal state and 24 h after infusion of live Escherichia coli. VLDL, labeled with [2- 3 H]glycerol and [1- 14 C]palmitic acid, was used to trace VLDL kinetics and oxidation, and [1- 13 C]palmitic acid bound to albumin was infused simultaneously to quantify kinetics and oxidation of free fatty acid (FFA) in plasma. Sepsis caused a fivefold increase in the rate of VLDL production (RaVLDL). In the control dogs, the direct oxidation of VLDL-fatty acids was not an important contributor to their overall energy metabolism, but in dogs with sepsis, 17% of the total rate of CO2 production could be accounted for by VLDL-fatty acid oxidation. When glucose was infused into dogs with insulin and glucagon levels clamped at basal levels (by means of infusion of somatostatin and replacement of the hormones), RaVLDL increased significantly in the control dogs, but it did not increase further in dogs with sepsis. The authors conclude that the increase in triglyceride concentration in fasting dogs with gram-negative sepsis is the result of an increase in VLDL production and that the fatty acids in VLDL can serve as an important source of energy in sepsis

  1. Antimicrobial Photodynamic Therapy to Kill Gram-negative Bacteria

    Science.gov (United States)

    Sperandio, Felipe F; Huang, Ying-Ying; Hamblin, Michael R

    2013-01-01

    Antimicrobial photodynamic therapy (PDT) or photodynamic inactivation (PDI) is a new promising strategy to eradicate pathogenic microorganisms such as Gram-positive and Gram-negative bacteria, yeasts and fungi. The search for new approaches that can kill bacteria but do not induce the appearance of undesired drug-resistant strains suggests that PDT may have advantages over traditional antibiotic therapy. PDT is a non-thermal photochemical reaction that involves the simultaneous presence of visible light, oxygen and a dye or photosensitizer (PS). Several PS have been studied for their ability to bind to bacteria and efficiently generate reactive oxygen species (ROS) upon photostimulation. ROS are formed through type I or II mechanisms and may inactivate several classes of microbial cells including Gram-negative bacteria such as Pseudomonas aeruginosa, which are typically characterized by an impermeable outer cell membrane that contains endotoxins and blocks antibiotics, dyes, and detergents, protecting the sensitive inner membrane and cell wall. This review covers significant peer-reviewed articles together with US and World patents that were filed within the past few years and that relate to the eradication of Gram-negative bacteria via PDI or PDT. It is organized mainly according to the nature of the PS involved and includes natural or synthetic food dyes; cationic dyes such as methylene blue and toluidine blue; tetrapyrrole derivatives such as phthalocyanines, chlorins, porphyrins, chlorophyll and bacteriochlorophyll derivatives; functionalized fullerenes; nanoparticles combined with different PS; other formulations designed to target PS to bacteria; photoactive materials and surfaces; conjugates between PS and polycationic polymers or antibodies; and permeabilizing agents such as EDTA, PMNP and CaCl2. The present review also covers the different laboratory animal models normally used to treat Gram-negative bacterial infections with antimicrobial PDT. PMID

  2. Dustborne and airborne gram-positive and gram-negative bacteria in high versus low ERMI homes

    Science.gov (United States)

    The study aimed at investigating Gram-positive and Gram-negative bacteria in moldy and non-moldy homes, as defined by the home's Environmental Relative Moldiness Index (ERMI) value. The ERMI values were determined from floor dust samples in 2010 and 2011 and homes were classified...

  3. How bacterial cell division might cheat turgor pressure - a unified mechanism of septal division in Gram-positive and Gram-negative bacteria.

    Science.gov (United States)

    Erickson, Harold P

    2017-08-01

    An important question for bacterial cell division is how the invaginating septum can overcome the turgor force generated by the high osmolarity of the cytoplasm. I suggest that it may not need to. Several studies in Gram-negative bacteria have shown that the periplasm is isoosmolar with the cytoplasm. Indirect evidence suggests that this is also true for Gram-positive bacteria. In this case the invagination of the septum takes place within the uniformly high osmotic pressure environment, and does not have to fight turgor pressure. A related question is how the V-shaped constriction of Gram-negative bacteria relates to the plate-like septum of Gram-positive bacteria. I collected evidence that Gram-negative bacteria have a latent capability of forming plate-like septa, and present a model in which septal division is the basic mechanism in both Gram-positive and Gram-negative bacteria. © 2017 WILEY Periodicals, Inc.

  4. Peritoneal Dialysis-Related Peritonitis Due to Melioidosis: A Potentially Devastating Condition.

    Science.gov (United States)

    Kanjanabuch, Talerngsak; Lumlertgul, Nuttha; Pearson, Lachlan J; Chatsuwan, Tanittha; Pongpirul, Krit; Leelahavanichkul, Asada; Thongbor, Nisa; Nuntawong, Gunticha; Praderm, Laksamon; Wechagama, Pantiwa; Narenpitak, Surapong; Wechpradit, Apinya; Punya, Worauma; Halue, Guttiga; Naka, Phetpailin; Jeenapongsa, Somboon; Eiam-Ong, Somchai

    2017-01-01

    ♦ BACKGROUND: Melioidosis, an infectious disease caused by Burkholderia pseudomallei , is endemic in Southeast Asia and Northern Australia. Although a wide range of clinical manifestations from this organism are known, peritonitis associated with peritoneal dialysis (PD) has rarely been reported. ♦ PATIENTS AND METHODS: Peritoneal dialysis patients from all regions in Thailand were eligible for the study if they had peritonitis and either peritoneal fluid or effluent culture positive for B. pseudomallei . Patient data obtained included baseline characteristics, laboratory investigations, treatments, and clinical outcomes. When possible, PD fluid and removed Tenckhoff (TK) catheters were submitted for analyses of minimal inhibitory concentration (MIC) and microbial biofilm, respectively. ♦ RESULTS: Twenty-six patients were identified who were positive for peritoneal B. pseudomallei infection. The recorded mean age was 50 ± 15 (24 - 75) years, and the majority (58%) were female. Most of the cases were farmers living in Northeastern and Northern Thailand. Almost half of the cases had diabetes. Infections were reported commonly during the monsoon season and winter. The clinical presentations of peritonitis were similar to the manifestations from other microorganisms. Nine patients (41%) died (7 from sepsis), 6 fully recovered, and 7 switched to permanent hemodialysis. The mortality was potentially associated with sepsis ( p = 0.007), infection during the monsoon season ( p = 0.017), high initial dialysate neutrophils ( p = 0.045), and high hematocrit ( p = 0.045). Although no antibiotic resistance to ceftazidime and carbapenems was detected, approximately 50% of patients died with this treatment. Microbial biofilms were identified on the luminal surface of 4 out of 5 TK catheters, but the removal of the catheter did not alter the outcomes. ♦ CONCLUSION: Peritoneal dialysis-related peritonitis due to melioidosis is uncommon but highly fatal. Increased awareness

  5. Immunotherapy in the management of sepsis.

    Science.gov (United States)

    Sikora, Janusz Piotr

    2002-01-01

    This work presents the role of Gram-negative bacteria endotoxins, pro- and anti-inflammatory cytokines and reactive oxygen species (ROS) in the complex and not fully explained pathogenesis of sepsis. The so-called "respiratory burst" of neutrophils and the antioxidant mechanisms of the host are also discussed. The work focuses on possible approaches to the management of sepsis connected with immunotherapy. Neutralization of endotoxin lipopolysaccharide (LPS), anti-tumor necrosis factor alpha (TNF-alpha) therapy with monoclonal antibodies or pentoxifylline (PTXF), as well as soluble recombinant cytokine agonists and antagonists used in clinical trials are taken into consideration. In addition, cytokine manipulation therapy, anti-adhesion techniques, glucocorticoides and antioxidant barrier interference are also described. So far there has been no immunotherapy of sepsis in children of proven clinical efficacy, which prompts an aggressive examination of the immune system aimed at affecting its function.

  6. Association of different types of milk feeding with blood culture positive neonatal sepsis

    International Nuclear Information System (INIS)

    Anwar, M.; Waheed, K.A.I.; Rehman, A.

    2014-01-01

    To ascertain and compare microbial growth pattern in blood culture of septic neonates who were either totally breast or formula fed. Study Design: Cross sectional study. Place and Duration of Study: The Children's Hospital Lahore, Pakistan from Feb 2012 to Dec 2012. Methodology: All clinically septic neonates, who were either exclusively breast fed or formula fed, were enrolled in the study. They were divided into two groups and studied for the type of organisms grown on blood culture. Group-A were breast fed and group-B were formula fed. Neonates who were blood culture negative or had growth of multiple organisms or had incomplete data or who died / left against medical advice before completing the required data or babies receiving milk feeding from multiple sources or no feeding at all were excluded. BACTEC technique was used for obtaining bacterial growth. SPSS version 19 was used for statistical analysis. Results: A total of 380 clinically septic neonates were enrolled. Each group consisted of 190 subjects. Incidence of culture positive sepsis in breast fed and in formula fed was 6.7% and 15.7% respectively (p-value = 0.0001). Overall, gram-negative organisms constituted the majority (16.1%). Thirty seven percent cultures grew coagulase negative Staphylococcus (CoNS) followed by Klebsiella spp (23.4%). In group A, gram-negative and gram-positive organisms were equally distributed whilst in group-B, gram-negative organisms were three times more frequent than gram-positive organisms. Predominant pattern of organisms was also different in the two groups. In group-A, CoNS was predominant while in group-B, Klebsiella spp. was most frequent. Conclusion: Culture positive sepsis is more than two times greater in formula fed babies and is caused predominantly by gram-negative organisms whilst in breast fed babies, CoNS is the commonest organism. (author)

  7. The etiology of neonatal sepsis and patterns of antibiotic resistance

    International Nuclear Information System (INIS)

    Waheed, M.; Laeeq, A.; Maqbool, S.

    2003-01-01

    Objective: To study the patterns of causative bacteria and antibiotic resistance in neonatal sepsis. Results: Among 228 cases included in the study, the male to female ratio was 2.1 to 1. The gestational age was less than 36 weeks in 68 (30%) cases and low birth weight babies were 143 (62.6%). History of birth asphyxia was present in 103 (45%) cases. There were 142 (62.3%) cases of early onset ( 7 days). Out of 233 positive blood cultures Escherichia coli was found to be commonest (47.8%, n =111, p<0.05) both in early onset (47.8%, n=68, p <0.05) and late onset sepsis (47.3%,n=43, p<0.05). Staphylococcus aureus was the most common among gram positive organism. Resistance to cefotaxime, ceftazidime and amikacin was 34% to 80% and to ciprofloxacin 13% to 72%. A total of 64 cases (28%) died. Mortality was four times higher in early onset sespis. Conclusion: Gram negative bacteria are the commenst cause of neonatal sepsis. The resistance to the commonly used antibiotics is alarmingly high. Mortality is four times higher in early one set sepsis. (author)

  8. Clinical characteristics and outcomes of bacteraemic melioidosis in a teaching hospital in a northeastern state of Malaysia: a five-year review.

    Science.gov (United States)

    Deris, Zakuan Zainy; Hasan, Habsah; Siti Suraiya, Mohd Noor

    2010-08-04

    Melioidosis is an important public health problem causing community acquired sepsis in the northeastern part of Malaysia. From January 2001 to December 2005, we reviewed case reports of all bacteraemic melioidosis admitted to a tertiary teaching hospital, Hospital Universiti Sains Malaysia. Thirty-five patients had positive blood culture for meliodosis and 27 case reports were traceable for further analysis. The mean age was 46.8 + 20.0 years. Twenty patients (74.1%) were male. The main clinical presentation was fever that occurred in 23 (85.2%) patients. Eighteen patients (66.7%) had lung involvement and three patients had liver abscess. Two patients presented with scrotal swelling, one of whom further developed Fournier's Gangrene. Nineteen (70.4%) patients had underlying diabetes, five of whom were newly diagnosed during the admission. Thirteen (48.1%) patients were treated with high-dose ceftazidime and six (22.2%) patients were treated with imipenem. Eight (29.6%) patients were not given anti-melioidosis therapy because the causative agents were not identified until after the patients died. The patients were admitted 16.8 days + 18.1. Seventeen patients (63.0%) died in this series, 13 patients of whom died within four days of admission. The wide range of clinical presentations and the fatal outcomes of melioidosis require a high level of suspicion among physicians to develop an early appropriate therapy and reduce the mortality rate.

  9. Risk factors for multidrug-resistant Gram-negative infection in burn patients.

    Science.gov (United States)

    Vickers, Mark L; Dulhunty, Joel M; Ballard, Emma; Chapman, Paul; Muller, Michael; Roberts, Jason A; Cotta, Menino O

    2018-05-01

    Infection with multidrug-resistant (MDR) Gram-negative organisms leads to poorer outcomes in the critically ill burn patient. The aim of this study was to identify the risk factors for MDR Gram-negative pathogen infection in critically ill burn patients admitted to a major tertiary referral intensive care unit (ICU) in Australia. A retrospective case-control study of all adult burn patients admitted over a 7-year period was conducted. Twenty-one cases that cultured an MDR Gram-negative organism were matched with 21 controls of similar age, gender, burn size and ICU stay. Multivariable conditional logistic regression was used to individually assess risk factors after adjusting for Acute Burn Severity Index. Adjusted odds ratios (ORs) were reported. P-values negative infection included superficial partial thickness burn size (OR: 1.08; 95% confidence interval (CI): 1.01-1.16; P-value: 0.034), prior meropenem exposure (OR: 10.39; 95% CI: 0.96-112.00; P-value: 0.054), Gram-negative colonization on admission (OR: 9.23; 95% CI: 0.65-130.15; P-value: 0.10) and escharotomy (OR: 2.66; 95% CI: 0.52-13.65; P-value: 0.24). For cases, mean age was 41 (SD: 13) years, mean total body surface area burned was 47% (SD: 18) and mean days in ICU until MDR specimen collection was 17 (SD: 10) days. Prior meropenem exposure, Gram-negative colonization on admission, escharotomy and superficial partial thickness burn size may be potentially important factors for increasing the risk of MDR Gram-negative infection in the critically ill burn patient. © 2017 Royal Australasian College of Surgeons.

  10. Bacteriological profile of neonatal sepsis in a secondary care hospital in rural Tamil Nadu, Southern India.

    Science.gov (United States)

    Pavan Kumar, Doniparthi Venkata; Mohan, Jesinth; Rakesh, P S; Prasad, Jasmine; Joseph, Lenikumar

    2017-01-01

    Neonatal sepsis is a leading cause of neonatal mortality and morbidity in the world. The objective of the current study was to detect the common causative microorganisms of neonatal sepsis and their antimicrobial resistance patterns in a rural secondary hospital in Tamil Nadu, India. Neonates (0-28 days) admitted to this newborn care unit from October 2013 to September 2015, with a diagnosis of probable sepsis were studied. All the enrolled babies had blood cultures taken and were followed up till final outcome, which was discharge or death, irrespective of culture result. Univariate analysis was performed for factors associated with culture positivity, generating odds ratios, and confidence intervals. Among the 107 babies with a diagnosis of probable sepsis, 28 (26.2%) had shown bacteria in culture. The majority (94.4%) were of early-onset sepsis. The predominant organisms were Staphylococcus aureus (10/28) and Klebsiella (6/28). 100% of Gram-negative bacilli and 90% of Staphylococcus were resistant to Ampicillin. Gentamicin resistance among Gram-negative bacilli and Staphylococcus was 52.9% and 20%, respectively, while third-generation cephalosporin resistance was 31.2% and 20%, respectively. Among the neonates diagnosed as probable sepsis, idiopathic prematurity ( P = 0.007) was found to have a statistically significant association with culture-positive sepsis. The culture positivity rate among the neonates with probable sepsis in the current study was 26%. An alarmingly high degree of antibiotic resistance observed calls for robust infection control practices and an urgent evaluation and development of individual and national antibiotic policies for neonatal sepsis.

  11. Severe Cystic Periventricular Leukomalacia in a Premature Infant with Capnocytophaga Sepsis

    Directory of Open Access Journals (Sweden)

    W. Thomas Bass

    2014-11-01

    Full Text Available Capnocytophaga is an opportunistic gram-negative anaerobic bacillus found in the oropharyngeal cavity of mammals and is associated with periodontal disease in humans. Sepsis, osteomyelitis, lung abscess, endocarditis, and meningitis have been reported in humans following animal bites. Perinatal infection with Capnocytophaga is infrequent and is generally considered to have a low risk of morbidity to the mother and fetus. We report a case of neonatal Capnocytophaga sepsis associated with the development of severe cystic periventricular leukomalacia

  12. An eight-year review of blood culture and susceptibility among sepsis cases in an emergency department in Northeastern Malaysia.

    Science.gov (United States)

    Hashairi, F; Hasan, H; Azlan, K; Deris, Z Z

    2011-12-01

    An understanding of common pathogens and their antibiotic sensitivity patterns is critical for proper management of sepsis in Emergency Department (ED). The goal of the study was to identify common organisms isolated from blood cultures of patients attended to ED and their antimicrobial susceptibility. Beginning from 2002, all cases of positive blood culture collected by the ED, Hospital Universiti Sains Malaysia (HUSM) were recorded and analysed. Over the period of eight years, we documented 995 cases of positive blood cultures. Of these samples, 549 (55.2%) were Gram-negative bacteria; 419 (42.1%) were Gram-positive bacteria; 10 (1.0%) were anaerobic organisms; 10 (1.0%) were fungus; and 7 (0.7%) cases were mixed organisms. Gram-negative bacteria were observed to develop more resistance to antimicrobial agents, especially those commonly used in an outpatient setting with less than 80% sensitivity to ampicillin, cotrimoxazole and ciprofloxacin. By contrast, there has been no marked change in the sensitivity trends of Gram-positive bacteria over the same period. In conclusion, ED physicians are more equipped to initiate empirical antimicrobial therapy especially when dealing with possibility of Gram-negative sepsis.

  13. Predictors of positive blood culture and deaths among neonates with suspected neonatal sepsis in a tertiary hospital, Mwanza- Tanzania

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    Jeremiah Seni

    2010-06-01

    Full Text Available Abstract Background Neonatal sepsis is a significant cause of morbidity and mortality in neonates. Appropriate clinical diagnosis and empirical treatment in a given setting is crucial as pathogens of bacterial sepsis and antibiotic sensitivity pattern can considerably vary in different settings. This study was conducted at Bugando Medical Centre (BMC, Tanzania to determine the prevalence of neonatal sepsis, predictors of positive blood culture, deaths and antimicrobial susceptibility, thus providing essential information to formulate a policy for management of neonatal sepsis. Methods This was a prospective cross sectional study involving 300 neonates admitted at BMC neonatal unit between March and November 2009. Standard data collection form was used to collect all demographic data and clinical characteristics of neonates. Blood culture was done on Brain Heart Infusion broth followed by identification of isolates using conventional methods and testing for their susceptibility to antimicrobial agents using the disc diffusion method. Results Among 770 neonates admitted during the study period; 300 (38.9% neonates were diagnosed to have neonatal sepsis by WHO criteria. Of 300 neonates with clinical neonatal sepsis 121(40% and 179(60% had early and late onset sepsis respectively. Positive blood culture was found in 57 (47.1% and 92 (51.4% among neonates with early and late onset neonatal sepsis respectively (p = 0.466. Predictors of positive blood culture in both early and late onset neonatal sepsis were inability to feed, lethargy, cyanosis, meconium stained liquor, premature rupture of the membrane and convulsion. About 49% of gram negatives isolates were resistant to third generation cephalosporins and 28% of Staphylococcus aureus were found to be Methicillin resistant Staphylococcus aureus (MRSA. Deaths occurred in 57 (19% of neonates. Factors that predicted deaths were positive blood culture (p = 0.0001, gram negative sepsis (p = 0.0001 and

  14. Antibacterial Activity of Silver-Graphene Quantum Dots Nanocomposites Against Gram-Positive and Gram-Negative Bacteria

    Science.gov (United States)

    Habiba, Khaled (Inventor); Makarov, Vladimir (Inventor); Weiner, Brad R (Inventor); Morell, Gerardo (Inventor)

    2018-01-01

    The invention provides a composite of silver nanoparticles decorated with graphene quantum dots (Ag-GQDs) using pulsed laser synthesis. The nanocomposites were functionalized with polyethylene glycol (PEG). A concentration of 150 .mu.g/mL of Ag-GQDs, a non-toxic level for human cells, exhibits strong antibacterial activity against both Gram-Positive and Gram-Negative Bacteria.

  15. Combating multidrug-resistant Gram-negative bacterial infections.

    Science.gov (United States)

    Xu, Ze-Qi; Flavin, Michael T; Flavin, John

    2014-02-01

    Multidrug-resistant (MDR) bacterial infections, especially those caused by Gram-negative pathogens, have emerged as one of the world's greatest health threats. The development of novel antibiotics to treat MDR Gram-negative bacteria has, however, stagnated over the last half century. This review provides an overview of recent R&D activities in the search for novel antibiotics against MDR Gram-negatives. It provides emphasis in three key areas. First, the article looks at new analogs of existing antibiotic molecules such as β-lactams, tetracyclines, and aminoglycoside as well as agents against novel bacterial targets such as aminoacyl-tRNA synthetase and peptide deformylase. Second, it also examines alternative strategies to conventional approaches including cationic antimicrobial peptides, siderophores, efflux pump inhibitors, therapeutic antibodies, and renewed interest in abandoned treatments or those with limited indications. Third, the authors aim to provide an update on the current clinical development status for each drug candidate. The traditional analog approach is insufficient to meet the formidable challenge brought forth by MDR superbugs. With the disappointing results of the genomics approach for delivering novel targets and drug candidates, alternative strategies to permeate the bacterial cell membrane, enhance influx, disrupt efflux, and target specific pathogens via therapeutic antibodies are attractive and promising. Coupled with incentivized business models, governmental policies, and a clarified regulatory pathway, it is hoped that the antibiotic pipeline will be filled with an effective armamentarium to safeguard global health.

  16. Volatile metabolites from some gram-negative bacteria

    DEFF Research Database (Denmark)

    Schöller, Charlotte; Molin, Søren; Wilkins, Ken

    1997-01-01

    A survey of volatile organic compounds (VOCs) excreted from various Gram-negative bacteria (Pseudomonas spp., Serratia spp. and Enterobacter spp.) was carried out. Compounds were identified by gas chromatography-mass spectrometry. VOCs identified included dimethyl disulphide, dimethyl trisulphide...

  17. Gram negative wound infection in hospitalised adult burn patients--systematic review and metanalysis-.

    Science.gov (United States)

    Azzopardi, Ernest A; Azzopardi, Elayne; Camilleri, Liberato; Villapalos, Jorge; Boyce, Dean E; Dziewulski, Peter; Dickson, William A; Whitaker, Iain S

    2014-01-01

    Gram negative infection is a major determinant of morbidity and survival. Traditional teaching suggests that burn wound infections in different centres are caused by differing sets of causative organisms. This study established whether Gram-negative burn wound isolates associated to clinical wound infection differ between burn centres. Studies investigating adult hospitalised patients (2000-2010) were critically appraised and qualified to a levels of evidence hierarchy. The contribution of bacterial pathogen type, and burn centre to the variance in standardised incidence of Gram-negative burn wound infection was analysed using two-way analysis of variance. Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter baumanni, Enterobacter spp., Proteus spp. and Escherichia coli emerged as the commonest Gram-negative burn wound pathogens. Individual pathogens' incidence did not differ significantly between burn centres (F (4, 20) = 1.1, p = 0.3797; r2 = 9.84). Gram-negative infections predominate in burn surgery. This study is the first to establish that burn wound infections do not differ significantly between burn centres. It is the first study to report the pathogens responsible for the majority of Gram-negative infections in these patients. Whilst burn wound infection is not exclusive to these bacteria, it is hoped that reporting the presence of this group of common Gram-negative "target organisms" facilitate clinical practice and target research towards a defined clinical demand.

  18. Disease: H00317 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available H00317 Melioidosis Melioidosis is an infection caused by the gram-negative soil-dw...elling bacillus Burkholderia pseudomallei. It predominantly affects people in regular contact with soil and

  19. Lymphocytic Pleural Effusion in Acute Melioidosis

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    Kuo-Mou Chung

    2007-10-01

    Full Text Available An endemic outbreak of melioidosis developed in southern Taiwan following a flood caused by a typhoon in July 2005. A total of 27 patients were diagnosed with the acute and indigenous form of pulmonary melioidosis. Parapneumonic pleural effusions were noted on chest X-rays in six patients. Thoracentesis was done in three patients and all revealed lymphocyte predominance in differential cell count. Burkholderia pseudomallei was isolated in the pleural effusion in one of them. All three patients survived after antibiotic treatment. Lymphocytic pleural effusion is generally seen in tuberculosis or malignancy. However, our findings suggest that melioidosis should be considered in the differential diagnosis of lymphocytic pleural effusion.

  20. Incidence of carbapenem-resistant gram negatives in Italian transplant recipients: a nationwide surveillance study.

    Science.gov (United States)

    Lanini, Simone; Costa, Alessandro Nanni; Puro, Vincenzo; Procaccio, Francesco; Grossi, Paolo Antonio; Vespasiano, Francesca; Ricci, Andrea; Vesconi, Sergio; Ison, Michael G; Carmeli, Yehuda; Ippolito, Giuseppe

    2015-01-01

    Bacterial infections remain a challenge to solid organ transplantation. Due to the alarming spread of carbapenem-resistant gram negative bacteria, these organisms have been frequently recognized as cause of severe infections in solid organ transplant recipients. Between 15 May and 30 September 2012 we enrolled 887 solid organ transplant recipients in Italy with the aim to describe the epidemiology of gram negative bacteria spreading, to explore potential risk factors and to assess the effect of early isolation of gram negative bacteria on recipients' mortality during the first 90 days after transplantation. During the study period 185 clinical isolates of gram negative bacteria were reported, for an incidence of 2.39 per 1000 recipient-days. Positive cultures for gram negative bacteria occurred early after transplantation (median time 26 days; incidence rate 4.33, 1.67 and 1.14 per 1,000 recipient-days in the first, second and third month after SOT, respectively). Forty-nine of these clinical isolates were due to carbapenem-resistant gram negative bacteria (26.5%; incidence 0.63 per 1000 recipient-days). Carbapenems resistance was particularly frequent among Klebsiella spp. isolates (49.1%). Recipients with longer hospital stay and those who received either heart or lung graft were at the highest risk of testing positive for any gram negative bacteria. Moreover recipients with longer hospital stay, lung recipients and those admitted to hospital for more than 48h before transplantation had the highest probability to have culture(s) positive for carbapenem-resistant gram negative bacteria. Forty-four organ recipients died (0.57 per 1000 recipient-days) during the study period. Recipients with at least one positive culture for carbapenem-resistant gram negative bacteria had a 10.23-fold higher mortality rate than those who did not. The isolation of gram-negative bacteria is most frequent among recipient with hospital stays >48 hours prior to transplant and in those

  1. Incidence of carbapenem-resistant gram negatives in Italian transplant recipients: a nationwide surveillance study.

    Directory of Open Access Journals (Sweden)

    Simone Lanini

    Full Text Available Bacterial infections remain a challenge to solid organ transplantation. Due to the alarming spread of carbapenem-resistant gram negative bacteria, these organisms have been frequently recognized as cause of severe infections in solid organ transplant recipients.Between 15 May and 30 September 2012 we enrolled 887 solid organ transplant recipients in Italy with the aim to describe the epidemiology of gram negative bacteria spreading, to explore potential risk factors and to assess the effect of early isolation of gram negative bacteria on recipients' mortality during the first 90 days after transplantation. During the study period 185 clinical isolates of gram negative bacteria were reported, for an incidence of 2.39 per 1000 recipient-days. Positive cultures for gram negative bacteria occurred early after transplantation (median time 26 days; incidence rate 4.33, 1.67 and 1.14 per 1,000 recipient-days in the first, second and third month after SOT, respectively. Forty-nine of these clinical isolates were due to carbapenem-resistant gram negative bacteria (26.5%; incidence 0.63 per 1000 recipient-days. Carbapenems resistance was particularly frequent among Klebsiella spp. isolates (49.1%. Recipients with longer hospital stay and those who received either heart or lung graft were at the highest risk of testing positive for any gram negative bacteria. Moreover recipients with longer hospital stay, lung recipients and those admitted to hospital for more than 48h before transplantation had the highest probability to have culture(s positive for carbapenem-resistant gram negative bacteria. Forty-four organ recipients died (0.57 per 1000 recipient-days during the study period. Recipients with at least one positive culture for carbapenem-resistant gram negative bacteria had a 10.23-fold higher mortality rate than those who did not.The isolation of gram-negative bacteria is most frequent among recipient with hospital stays >48 hours prior to transplant

  2. Glycosaminoglycans are involved in pathogen adherence to corneal epithelial cells differently for Gram-positive and Gram-negative bacteria

    Directory of Open Access Journals (Sweden)

    Beatriz García

    2016-11-01

    Full Text Available The epithelium of the cornea is continuously exposed to pathogens, and adhesion to epithelial cells is regarded as an essential first step in bacterial pathogenesis. In this article, the involvement of glycosaminoglycans in the adhesion of various pathogenic bacteria to corneal epithelial cells is analyzed. All microorganisms use glycosaminoglycans as receptors, but arranged in different patterns depending on the Gram-type of the bacterium. The heparan sulfate chains of syndecans are the main receptors, though other molecular species also seem to be involved, particularly in Gram-negative bacteria. Adherence is inhibited differentially by peptides, including heparin binding sequences, indicating the participation of various groups of Gram-positive and -negative adhesins. The length of the saccharides produces a major effect, and low molecular weight chains inhibit the binding of Gram-negative microorganisms but increase the adherence of Gram-positives. Pathogen adhesion appears to occur preferentially through sulfated domains, and is very dependent on N- and 6-O-sulfation of the glucosamine residue and, to a lesser extent, 2-O sulfation of uronic acid. These data show the differential use of corneal receptors, which could facilitate the development of new anti-infective strategies.

  3. Neonatal sepsis in rural India: timing, microbiology and antibiotic resistance in a population-based prospective study in the community setting.

    Science.gov (United States)

    Panigrahi, P; Chandel, D S; Hansen, N I; Sharma, N; Kandefer, S; Parida, S; Satpathy, R; Pradhan, L; Mohapatra, A; Mohapatra, S S; Misra, P R; Banaji, N; Johnson, J A; Morris, J G; Gewolb, I H; Chaudhry, R

    2017-08-01

    To examine the timing and microbiology of neonatal sepsis in a population-based surveillance in the Indian community setting. All live born infants in 223 villages of Odisha state were followed at home for 60 days. Suspect sepsis cases were referred to study hospitals for further evaluation including blood culture. Of 12 622 births, 842 were admitted with suspected sepsis of whom 95% were 4 to 60 days old. Culture-confirmed incidence of sepsis was 6.7/1000 births with 51% Gram negatives (Klebsiella predominating) and 26% Gram positives (mostly Staphylococcus aureus). A very high level of resistance to penicillin and ampicillin, moderate resistance to cephalosporins and extremely low resistance to Gentamicin and Amikacin was observed. The bacterial burden of sepsis in the Indian community is not high. Judicious choice of empiric antibiotics, antibiotic stewardship and alternate modalities should be considered for the management or prevention of neonatal sepsis in India.

  4. Type I and Type II mechanisms of antimicrobial photodynamic therapy: an in vitro study on gram-negative and gram-positive bacteria.

    Science.gov (United States)

    Huang, Liyi; Xuan, Yi; Koide, Yuichiro; Zhiyentayev, Timur; Tanaka, Masamitsu; Hamblin, Michael R

    2012-08-01

    Antimicrobial photodynamic therapy (APDT) employs a non-toxic photosensitizer (PS) and visible light, which in the presence of oxygen produce reactive oxygen species (ROS), such as singlet oxygen ((1) O(2), produced via Type II mechanism) and hydroxyl radical (HO(.), produced via Type I mechanism). This study examined the relative contributions of (1) O(2) and HO(.) to APDT killing of Gram-positive and Gram-negative bacteria. Fluorescence probes, 3'-(p-hydroxyphenyl)-fluorescein (HPF) and singlet oxygen sensor green reagent (SOSG) were used to determine HO(.) and (1) O(2) produced by illumination of two PS: tris-cationic-buckminsterfullerene (BB6) and a conjugate between polyethylenimine and chlorin(e6) (PEI-ce6). Dimethylthiourea is a HO(.) scavenger, while sodium azide (NaN(3)) is a quencher of (1) O(2). Both APDT and killing by Fenton reaction (chemical generation of HO(.)) were carried out on Gram-positive bacteria (Staphylococcus aureus and Enterococcus faecalis) and Gram-negative bacteria (Escherichia coli, Proteus mirabilis, and Pseudomonas aeruginosa). Conjugate PEI-ce6 mainly produced (1) O(2) (quenched by NaN(3)), while BB6 produced HO(.) in addition to (1) O(2) when NaN(3) potentiated probe activation. NaN(3) also potentiated HPF activation by Fenton reagent. All bacteria were killed by Fenton reagent but Gram-positive bacteria needed a higher concentration than Gram-negatives. NaN(3) potentiated Fenton-mediated killing of all bacteria. The ratio of APDT killing between Gram-positive and Gram-negative bacteria was 2 or 4:1 for BB6 and 25:1 for conjugate PEI-ce6. There was a NaN(3) dose-dependent inhibition of APDT killing using both PEI-ce6 and BB6 against Gram-negative bacteria while NaN(3) almost failed to inhibit killing of Gram-positive bacteria. Azidyl radicals may be formed from NaN(3) and HO(.). It may be that Gram-negative bacteria are more susceptible to HO(.) while Gram-positive bacteria are more susceptible to (1) O(2). The differences in Na

  5. Gram negative wound infection in hospitalised adult burn patients--systematic review and metanalysis-.

    Directory of Open Access Journals (Sweden)

    Ernest A Azzopardi

    Full Text Available BACKGROUND: Gram negative infection is a major determinant of morbidity and survival. Traditional teaching suggests that burn wound infections in different centres are caused by differing sets of causative organisms. This study established whether Gram-negative burn wound isolates associated to clinical wound infection differ between burn centres. METHODS: Studies investigating adult hospitalised patients (2000-2010 were critically appraised and qualified to a levels of evidence hierarchy. The contribution of bacterial pathogen type, and burn centre to the variance in standardised incidence of Gram-negative burn wound infection was analysed using two-way analysis of variance. PRIMARY FINDINGS: Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter baumanni, Enterobacter spp., Proteus spp. and Escherichia coli emerged as the commonest Gram-negative burn wound pathogens. Individual pathogens' incidence did not differ significantly between burn centres (F (4, 20 = 1.1, p = 0.3797; r2 = 9.84. INTERPRETATION: Gram-negative infections predominate in burn surgery. This study is the first to establish that burn wound infections do not differ significantly between burn centres. It is the first study to report the pathogens responsible for the majority of Gram-negative infections in these patients. Whilst burn wound infection is not exclusive to these bacteria, it is hoped that reporting the presence of this group of common Gram-negative "target organisms" facilitate clinical practice and target research towards a defined clinical demand.

  6. Bioengineered nisin A derivatives with enhanced activity against both Gram positive and Gram negative pathogens.

    Directory of Open Access Journals (Sweden)

    Des Field

    Full Text Available Nisin is a bacteriocin widely utilized in more than 50 countries as a safe and natural antibacterial food preservative. It is the most extensively studied bacteriocin, having undergone decades of bioengineering with a view to improving function and physicochemical properties. The discovery of novel nisin variants with enhanced activity against clinical and foodborne pathogens has recently been described. We screened a randomized bank of nisin A producers and identified a variant with a serine to glycine change at position 29 (S29G, with enhanced efficacy against S. aureus SA113. Using a site-saturation mutagenesis approach we generated three more derivatives (S29A, S29D and S29E with enhanced activity against a range of Gram positive drug resistant clinical, veterinary and food pathogens. In addition, a number of the nisin S29 derivatives displayed superior antimicrobial activity to nisin A when assessed against a range of Gram negative food-associated pathogens, including E. coli, Salmonella enterica serovar Typhimurium and Cronobacter sakazakii. This is the first report of derivatives of nisin, or indeed any lantibiotic, with enhanced antimicrobial activity against both Gram positive and Gram negative bacteria.

  7. Bioengineered Nisin A Derivatives with Enhanced Activity against Both Gram Positive and Gram Negative Pathogens

    Science.gov (United States)

    Field, Des; Begley, Maire; O’Connor, Paula M.; Daly, Karen M.; Hugenholtz, Floor; Cotter, Paul D.; Hill, Colin; Ross, R. Paul

    2012-01-01

    Nisin is a bacteriocin widely utilized in more than 50 countries as a safe and natural antibacterial food preservative. It is the most extensively studied bacteriocin, having undergone decades of bioengineering with a view to improving function and physicochemical properties. The discovery of novel nisin variants with enhanced activity against clinical and foodborne pathogens has recently been described. We screened a randomized bank of nisin A producers and identified a variant with a serine to glycine change at position 29 (S29G), with enhanced efficacy against S. aureus SA113. Using a site-saturation mutagenesis approach we generated three more derivatives (S29A, S29D and S29E) with enhanced activity against a range of Gram positive drug resistant clinical, veterinary and food pathogens. In addition, a number of the nisin S29 derivatives displayed superior antimicrobial activity to nisin A when assessed against a range of Gram negative food-associated pathogens, including E. coli, Salmonella enterica serovar Typhimurium and Cronobacter sakazakii. This is the first report of derivatives of nisin, or indeed any lantibiotic, with enhanced antimicrobial activity against both Gram positive and Gram negative bacteria. PMID:23056510

  8. Bacteriological profile of neonatal sepsis in a secondary care hospital in rural Tamil Nadu, Southern India

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    Doniparthi Venkata Pavan Kumar

    2017-01-01

    Full Text Available Introduction: Neonatal sepsis is a leading cause of neonatal mortality and morbidity in the world. The objective of the current study was to detect the common causative microorganisms of neonatal sepsis and their antimicrobial resistance patterns in a rural secondary hospital in Tamil Nadu, India. Materials and Methods: Neonates (0–28 days admitted to this newborn care unit from October 2013 to September 2015, with a diagnosis of probable sepsis were studied. All the enrolled babies had blood cultures taken and were followed up till final outcome, which was discharge or death, irrespective of culture result. Univariate analysis was performed for factors associated with culture positivity, generating odds ratios, and confidence intervals. Results: Among the 107 babies with a diagnosis of probable sepsis, 28 (26.2% had shown bacteria in culture. The majority (94.4% were of early-onset sepsis. The predominant organisms were Staphylococcus aureus (10/28 and Klebsiella (6/28. 100% of Gram-negative bacilli and 90% of Staphylococcus were resistant to Ampicillin. Gentamicin resistance among Gram-negative bacilli and Staphylococcus was 52.9% and 20%, respectively, while third-generation cephalosporin resistance was 31.2% and 20%, respectively. Among the neonates diagnosed as probable sepsis, idiopathic prematurity (P = 0.007 was found to have a statistically significant association with culture-positive sepsis. Conclusion: The culture positivity rate among the neonates with probable sepsis in the current study was 26%. An alarmingly high degree of antibiotic resistance observed calls for robust infection control practices and an urgent evaluation and development of individual and national antibiotic policies for neonatal sepsis.

  9. Gram-positive and gram-negative bacteria induce different patterns of cytokine production in human mononuclear cells irrespective of taxonomic relatedness.

    Science.gov (United States)

    Skovbjerg, Susann; Martner, Anna; Hynsjö, Lars; Hessle, Christina; Olsen, Ingar; Dewhirst, Floyd E; Tham, Wilhelm; Wold, Agnes E

    2010-01-01

    Upon bacterial stimulation, tissue macrophages produce a variety of cytokines that orchestrate the immune response that clears the infection. We have shown that Gram-positives induce higher levels of interleukin-12 (IL-12), interferon-gamma (IFN-gamma), and tumor necrosis factor (TNF) from human peripheral blood mononuclear cells (PBMCs) than do Gram-negatives, which instead induce more of IL-6, IL-8, and IL-10. Here, we study whether these patterns follows or crosses taxonomic borders. PBMCs from blood donors were incubated with UV-inactivated bacteria representing 37 species from five phyla. IL-12, TNF, IL-1beta, IL-6, IL-8, and IL-10 were measured in the supernatants after 24 h and IFN-gamma after 5 days. Irrespective of phylogenetic position, Gram-positive bacteria induced much more IL-12 (nine times more on average) and IFN-gamma (seven times), more TNF (three times), and slightly more IL-1beta (1.5 times) than did Gram-negatives, which instead induced more IL-6 (1.5 times), IL-8 (1.9 times), and IL-10 (3.3 times) than did Gram-positives. A notable exception was the Gram-positive Listeria monocytogenes, which induced very little IL-12, IFN-gamma, and TNF. The results confirm the fundamental difference in innate immune responses to Gram-positive and Gram-negative bacteria, which crosses taxonomic borders and probably reflects differences in cell wall structure.

  10. Pleural effusion adenosine deaminase: a candidate biomarker to discriminate between Gram-negative and Gram-positive bacterial infections of the pleural space

    Directory of Open Access Journals (Sweden)

    Ruolin Li

    2016-05-01

    Full Text Available OBJECTIVES: Delay in the treatment of pleural infection may contribute to its high mortality. In this retrospective study, we aimed to evaluate the diagnostic accuracy of pleural adenosine deaminase in discrimination between Gram-negative and Gram-positive bacterial infections of the pleural space prior to selecting antibiotics. METHODS: A total of 76 patients were enrolled and grouped into subgroups according to Gram staining: 1 patients with Gram-negative bacterial infections, aged 53.2±18.6 years old, of whom 44.7% had empyemas and 2 patients with Gram-positive bacterial infections, aged 53.5±21.5 years old, of whom 63.1% had empyemas. The pleural effusion was sampled by thoracocentesis and then sent for adenosine deaminase testing, biochemical testing and microbiological culture. The Mann-Whitney U test was used to examine the differences in adenosine deaminase levels between the groups. Correlations between adenosine deaminase and specified variables were also quantified using Spearman’s correlation coefficient. Moreover, receiver operator characteristic analysis was performed to evaluate the diagnostic accuracy of pleural effusion adenosine deaminase. RESULTS: Mean pleural adenosine deaminase levels differed significantly between Gram-negative and Gram-positive bacterial infections of the pleural space (191.8±32.1 U/L vs 81.0±16.9 U/L, p<0.01. The area under the receiver operator characteristic curve was 0.689 (95% confidence interval: 0.570, 0.792, p<0.01 at the cutoff value of 86 U/L. Additionally, pleural adenosine deaminase had a sensitivity of 63.2% (46.0-78.2%; a specificity of 73.7% (56.9-86.6%; positive and negative likelihood ratios of 2.18 and 0.50, respectively; and positive and negative predictive values of 70.6% and 66.7%, respectively. CONCLUSIONS: Pleural effusion adenosine deaminase is a helpful alternative biomarker for early and quick discrimination of Gram-negative from Gram-positive bacterial infections of the

  11. The structures of lipopolysaccharides from plant-associated gram-negative bacteria

    DEFF Research Database (Denmark)

    Molinaro, Antonio; Newman, Mari-Anne; Lanzetta, Rosa

    2009-01-01

    Gram-negative bacterial lipopolysaccharides (LPSs) have multiple roles in plant-microbe interactions. LPSs contribute to the low permeabilities of bacterial outer membranes, which act as barriers to protect bacteria from plant-derived antimicrobial substances. Conversely, perception of LPSs...... is an important prerequisite for any further understanding of the biological processes in plant-microbe interactions. Moreover, the LPSs from Gram-negative bacteria - especially those originating from plant-associated bacteria - are a great source of novel monosaccharides with unusual and occasionally astounding...

  12. Clinical and microbiological features of melioidosis in northern Vietnam.

    Science.gov (United States)

    Phuong, Doan Mai; Trung, Trinh Thanh; Breitbach, Katrin; Tuan, Nguyen Quang; Nübel, Ulrich; Flunker, Gisela; Khang, Dinh Duy; Quang, Nguyen Xuan; Steinmetz, Ivo

    2008-12-01

    Sporadic cases of melioidosis have been reported from Vietnam for decades, but clinical and epidemiological data for the indigenous population are still scarce. In this study, we reviewed clinical and demographic data of patients with culture-proven melioidosis diagnosed at a single large referral hospital in Hanoi between November 1997 and December 2005. We found that the clinical manifestations of melioidosis (with fatal septicaemia as the most common presentation), a high rate of underlying diseases, and a peak of cases admitted during the wet season, were similar to studies from other endemic areas. The geographical origin of patients with melioidosis showed that melioidosis existed in at least 18 northern provinces. The characterization of clinical Burkholderia pseudomallei strains by multilocus sequence typing identified 17 different sequence types (STs), 11 of which have (as yet) not been found outside Vietnam. Several of these STs presumably were generated through recent evolutionary events in this rapidly diversifying bacterial species, and thus, restricted geographic distribution may be a consequence of limited time passed since emergence. To our knowledge, this is the first report on a series of cases describing clinical and epidemiological features of melioidosis and corresponding B. pseudomallei strains from northern Vietnam.

  13. Different Use of Cell Surface Glycosaminoglycans As Adherence Receptors to Corneal Cells by Gram Positive and Gram Negative Pathogens

    Science.gov (United States)

    García, Beatriz; Merayo-Lloves, Jesús; Rodríguez, David; Alcalde, Ignacio; García-Suárez, Olivia; Alfonso, José F.; Baamonde, Begoña; Fernández-Vega, Andrés; Vazquez, Fernando; Quirós, Luis M.

    2016-01-01

    The epithelium of the cornea is continuously exposed to pathogens, and adhesion to epithelial cells is regarded as an essential first step in bacterial pathogenesis. In this article, the involvement of glycosaminoglycans in the adhesion of various pathogenic bacteria to corneal epithelial cells is analyzed. All microorganisms use glycosaminoglycans as receptors, but arranged in different patterns depending on the Gram-type of the bacterium. The heparan sulfate chains of syndecans are the main receptors, though other molecular species also seem to be involved, particularly in Gram-negative bacteria. Adherence is inhibited differentially by peptides, including heparin binding sequences, indicating the participation of various groups of Gram-positive, and -negative adhesins. The length of the saccharides produces a major effect, and low molecular weight chains inhibit the binding of Gram-negative microorganisms but increase the adherence of Gram-positives. Pathogen adhesion appears to occur preferentially through sulfated domains, and is very dependent on N- and 6-O-sulfation of the glucosamine residue and, to a lesser extent, 2-O sulfation of uronic acid. These data show the differential use of corneal receptors, which could facilitate the development of new anti-infective strategies. PMID:27965938

  14. Blood culture gram stain, acridine orange stain and direct sensitivity-based antimicrobial therapy of bloodstream infection in patients with trauma.

    Science.gov (United States)

    Behera, B; Mathur, P; Gupta, B

    2010-01-01

    The purpose of this study was to ascertain if the simple practice of Gram stain, acridine orange stain and direct sensitivity determination of positive blood culture bottles could be used to guide early and appropriate treatment in trauma patients with clinical suspicion of sepsis. The study also aimed to evaluate the error in interpreting antimicrobial sensitivity by direct method when compared to standard method and find out if specific antibiotic-organism combination had more discrepancies. Findings from consecutive episodes of blood stream infection at an Apex Trauma centre over a 12-month period are summarized. A total of 509 consecutive positive blood cultures were subjected to Gram staining. AO staining was done in BacT/ALERT-positive Gram-stain negative blood cultures. Direct sensitivity was performed from 369 blood culture broths, showing single type of growth in Gram and acridine orange staining. Results of direct sensitivity were compared to conventional sensitivity for errors. No 'very major' discrepancy was found in this study. About 5.2 and 1.8% minor error rates were noted in gram-positive and gram-negative bacteria, respectively, while comparing the two methods. Most of the discrepancies in gram-negative bacteria were noted in beta lactam - beta lactamase inhibitor combinations. Direct sensitivity testing was not reliable for reporting of methicillin and vancomycin resistance in Staphylococci. Gram stain result together with direct sensitivity testing is required for optimizing initial antimicrobial therapy in trauma patients with clinical suspicion of sepsis. Gram staining and AO staining proved particularly helpful in the early detection of candidaemia.

  15. Rationalizing the permeation of polar antibiotics into Gram-negative bacteria

    International Nuclear Information System (INIS)

    Scorciapino, Mariano Andrea; Acosta-Gutierrez, Silvia; Benkerrou, Dehbia; D’Agostino, Tommaso; Malloci, Giuliano; Samanta, Susruta; Bodrenko, Igor; Ceccarelli, Matteo

    2017-01-01

    The increasing level of antibiotic resistance in Gram-negative bacteria, together with the lack of new potential drug scaffolds in the pipeline, make the problem of infectious diseases a global challenge for modern medicine. The main reason that Gram-negative bacteria are particularly challenging is the presence of an outer cell-protecting membrane, which is not present in Gram-positive species. Such an asymmetric bilayer is a highly effective barrier for polar molecules. Several protein systems are expressed in the outer membrane to control the internal concentration of both nutrients and noxious species, in particular: (i) water-filled channels that modulate the permeation of polar molecules and ions according to concentration gradients, and (ii) efflux pumps to actively expel toxic compounds. Thus, besides expressing specific enzymes for drugs degradation, Gram-negative bacteria can also resist by modulating the influx and efflux of antibiotics, keeping the internal concentration low. However, there are no direct and robust experimental methods capable of measuring the permeability of small molecules, thus severely limiting our knowledge of the molecular mechanisms that ultimately control the permeation of antibiotics through the outer membrane. This is the innovation gap to be filled for Gram-negative bacteria. This review is focused on the permeation of small molecules through porins, considered the main path for the entry of polar antibiotics into Gram-negative bacteria. A fundamental understanding of how these proteins are able to filter small molecules is a prerequisite to design/optimize antibacterials with improved permeation. The level of sophistication of modern molecular modeling algorithms and the advances in new computer hardware has made the simulation of such complex processes possible at the molecular level. In this work we aim to share our experience and perspectives in the context of a multidisciplinary extended collaboration within the IMI

  16. Rationalizing the permeation of polar antibiotics into Gram-negative bacteria

    Science.gov (United States)

    Scorciapino, Mariano Andrea; Acosta-Gutierrez, Silvia; Benkerrou, Dehbia; D'Agostino, Tommaso; Malloci, Giuliano; Samanta, Susruta; Bodrenko, Igor; Ceccarelli, Matteo

    2017-03-01

    The increasing level of antibiotic resistance in Gram-negative bacteria, together with the lack of new potential drug scaffolds in the pipeline, make the problem of infectious diseases a global challenge for modern medicine. The main reason that Gram-negative bacteria are particularly challenging is the presence of an outer cell-protecting membrane, which is not present in Gram-positive species. Such an asymmetric bilayer is a highly effective barrier for polar molecules. Several protein systems are expressed in the outer membrane to control the internal concentration of both nutrients and noxious species, in particular: (i) water-filled channels that modulate the permeation of polar molecules and ions according to concentration gradients, and (ii) efflux pumps to actively expel toxic compounds. Thus, besides expressing specific enzymes for drugs degradation, Gram-negative bacteria can also resist by modulating the influx and efflux of antibiotics, keeping the internal concentration low. However, there are no direct and robust experimental methods capable of measuring the permeability of small molecules, thus severely limiting our knowledge of the molecular mechanisms that ultimately control the permeation of antibiotics through the outer membrane. This is the innovation gap to be filled for Gram-negative bacteria. This review is focused on the permeation of small molecules through porins, considered the main path for the entry of polar antibiotics into Gram-negative bacteria. A fundamental understanding of how these proteins are able to filter small molecules is a prerequisite to design/optimize antibacterials with improved permeation. The level of sophistication of modern molecular modeling algorithms and the advances in new computer hardware has made the simulation of such complex processes possible at the molecular level. In this work we aim to share our experience and perspectives in the context of a multidisciplinary extended collaboration within the IMI

  17. Neither Single nor a Combination of Routine Laboratory Parameters can Discriminate between Gram-positive and Gram-negative Bacteremia

    Science.gov (United States)

    Ratzinger, Franz; Dedeyan, Michel; Rammerstorfer, Matthias; Perkmann, Thomas; Burgmann, Heinz; Makristathis, Athanasios; Dorffner, Georg; Loetsch, Felix; Blacky, Alexander; Ramharter, Michael

    2015-01-01

    Adequate early empiric antibiotic therapy is pivotal for the outcome of patients with bloodstream infections. In clinical practice the use of surrogate laboratory parameters is frequently proposed to predict underlying bacterial pathogens; however there is no clear evidence for this assumption. In this study, we investigated the discriminatory capacity of predictive models consisting of routinely available laboratory parameters to predict the presence of Gram-positive or Gram-negative bacteremia. Major machine learning algorithms were screened for their capacity to maximize the area under the receiver operating characteristic curve (ROC-AUC) for discriminating between Gram-positive and Gram-negative cases. Data from 23,765 patients with clinically suspected bacteremia were screened and 1,180 bacteremic patients were included in the study. A relative predominance of Gram-negative bacteremia (54.0%), which was more pronounced in females (59.1%), was observed. The final model achieved 0.675 ROC-AUC resulting in 44.57% sensitivity and 79.75% specificity. Various parameters presented a significant difference between both genders. In gender-specific models, the discriminatory potency was slightly improved. The results of this study do not support the use of surrogate laboratory parameters for predicting classes of causative pathogens. In this patient cohort, gender-specific differences in various laboratory parameters were observed, indicating differences in the host response between genders. PMID:26522966

  18. Host defense peptides of thrombin modulate inflammation and coagulation in endotoxin-mediated shock and Pseudomonas aeruginosa sepsis

    DEFF Research Database (Denmark)

    Kalle, Martina; Papareddy, Praveen; Kasetty, Gopinath

    2012-01-01

    Gram-negative sepsis is accompanied by a disproportionate innate immune response and excessive coagulation mainly induced by endotoxins released from bacteria. Due to rising antibiotic resistance and current lack of other effective treatments there is an urgent need for new therapies. We here...... present a new treatment concept for sepsis and endotoxin-mediated shock, based on host defense peptides from the C-terminal part of human thrombin, found to have a broad and inhibitory effect on multiple sepsis pathologies. Thus, the peptides abrogate pro-inflammatory cytokine responses to endotoxin...

  19. Antimicrobial activity of metal oxide nanoparticles against Gram-positive and Gram-negative bacteria: a comparative study

    Directory of Open Access Journals (Sweden)

    Azam A

    2012-12-01

    Full Text Available Ameer Azam,1,2 Arham S Ahmed,2 Mohammad Oves,3 Mohammad S Khan,3 Sami S Habib,1 Adnan Memic11Centre of Nanotechnology, King Abdulaziz University, Jeddah, Saudi Arabia; 2Centre of Excellence in Materials Science (Nanomaterials, 3Department of Agricultural Microbiology, Aligarh Muslim University, Aligarh, IndiaBackground: Nanomaterials have unique properties compared to their bulk counterparts. For this reason, nanotechnology has attracted a great deal of attention from the scientific community. Metal oxide nanomaterials like ZnO and CuO have been used industrially for several purposes, including cosmetics, paints, plastics, and textiles. A common feature that these nanoparticles exhibit is their antimicrobial behavior against pathogenic bacteria. In this report, we demonstrate the antimicrobial activity of ZnO, CuO, and Fe2O3 nanoparticles against Gram-positive and Gram-negative bacteria.Methods and results: Nanosized particles of three metal oxides (ZnO, CuO, and Fe2O3 were synthesized by a sol–gel combustion route and characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, and transmission electron microscopy techniques. X-ray diffraction results confirmed the single-phase formation of all three nanomaterials. The particle sizes were observed to be 18, 22, and 28 nm for ZnO, CuO, and Fe2O3, respectively. We used these nanomaterials to evaluate their antibacterial activity against both Gram-negative (Escherichia coli and Pseudomonas aeruginosa and Gram-positive (Staphylococcus aureus and Bacillus subtilis bacteria.Conclusion: Among the three metal oxide nanomaterials, ZnO showed greatest antimicrobial activity against both Gram-positive and Gram-negative bacteria used in this study. It was observed that ZnO nanoparticles have excellent bactericidal potential, while Fe2O3 nanoparticles exhibited the least bactericidal activity. The order of antibacterial activity was demonstrated to be the following: ZnO > CuO > Fe2O3

  20. In vitro susceptibility of gram-negative bacterial isolates to chlorhexidine gluconate.

    Science.gov (United States)

    Mengistu, Y; Erge, W; Bellete, B

    1999-05-01

    To investigate the susceptibility of clinical isolates of gram-negative bacteria to chlorhexidine gluconate. Prospective laboratory study. Tikur Anbessa Hospital, Addis Ababa, Ethiopia. Clinical specimens from 443 hospital patients. Significant number of gram negative bacteria were not inhibited by chlorhexidine gluconate (0.02-0.05%) used for antisepsis. Four hundred and forty three strains of gram-negative bacteria were isolated from Tikur Anbessa Hospital patients. Escherichia coli (31.6%) and Klebsiella pneumoniae (23%) were the most frequently isolated bacteria followed by Proteus species (13.3%), Pseudomonas species (9.2%), and Citrobacter species (6.1%). Each organism was tested to chlorhexidine gluconate (CHG), minimum inhibitory concentration (MIC) ranging from 0.0001% to 1%w/v. All Salmonella species and E. coli were inhibited by CHG, MIC or = 0.1%). Our results showed that a significant number of the gram-negative bacterial isolates were not inhibited by CHG at the concentration used for disinfection of wounds or instruments (MIC 0.02-0.05% w/v). It is therefore important to select appropriate concentration of this disinfectant and rationally use it for disinfection and hospital hygiene. Continuing follow up and surveillance is also needed to detect resistant bacteria to chlorhexidine or other disinfectants in time.

  1. Mechanistic antimicrobial approach of extracellularly synthesized silver nanoparticles against gram positive and gram negative bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Tamboli, Dhawal P.; Lee, Dae Sung, E-mail: daesung@knu.ac.kr

    2013-09-15

    Highlights: • Bacterial extracelluar enzymes stabilized the silver nanoparticles (AgNPs). • AgNPs formation was characterized by analytical techniques such as UV–vis, TEM, and FTIR. • AgNPs showed obvious antimicrobial activity against both gram positive and gram negative microorganisms. • A mechanism of AgNPs’ antimicrobial activity was proposed. -- Abstract: The development of eco-friendly and reliable processes for the synthesis of nanoparticles has attracted considerable interest in nanotechnology. In this study, an extracellular enzyme system of a newly isolated microorganism, Exiguobacterium sp. KNU1, was used for the reduction of AgNO{sub 3} solutions to silver nanoparticles (AgNPs). The extracellularly biosynthesized AgNPs were characterized by UV–vis spectroscopy, Fourier transform infra-red spectroscopy and transmission electron microscopy. The AgNPs were approximately 30 nm (range 5–50 nm) in size, well-dispersed and spherical. The AgNPs were evaluated for their antimicrobial effects on different gram negative and gram positive bacteria using the minimum inhibitory concentration method. Reasonable antimicrobial activity against Salmonella typhimurium, Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus was observed. The morphological changes occurred in all the microorganisms tested. In particular, E. coli exhibited DNA fragmentation after being treated with the AgNPs. Finally, the mechanism for their bactericidal activity was proposed according to the results of scanning electron microscopy and single cell gel electrophoresis.

  2. Mechanistic antimicrobial approach of extracellularly synthesized silver nanoparticles against gram positive and gram negative bacteria

    International Nuclear Information System (INIS)

    Tamboli, Dhawal P.; Lee, Dae Sung

    2013-01-01

    Highlights: • Bacterial extracelluar enzymes stabilized the silver nanoparticles (AgNPs). • AgNPs formation was characterized by analytical techniques such as UV–vis, TEM, and FTIR. • AgNPs showed obvious antimicrobial activity against both gram positive and gram negative microorganisms. • A mechanism of AgNPs’ antimicrobial activity was proposed. -- Abstract: The development of eco-friendly and reliable processes for the synthesis of nanoparticles has attracted considerable interest in nanotechnology. In this study, an extracellular enzyme system of a newly isolated microorganism, Exiguobacterium sp. KNU1, was used for the reduction of AgNO 3 solutions to silver nanoparticles (AgNPs). The extracellularly biosynthesized AgNPs were characterized by UV–vis spectroscopy, Fourier transform infra-red spectroscopy and transmission electron microscopy. The AgNPs were approximately 30 nm (range 5–50 nm) in size, well-dispersed and spherical. The AgNPs were evaluated for their antimicrobial effects on different gram negative and gram positive bacteria using the minimum inhibitory concentration method. Reasonable antimicrobial activity against Salmonella typhimurium, Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus was observed. The morphological changes occurred in all the microorganisms tested. In particular, E. coli exhibited DNA fragmentation after being treated with the AgNPs. Finally, the mechanism for their bactericidal activity was proposed according to the results of scanning electron microscopy and single cell gel electrophoresis

  3. Extended-spectrum ß-lactamases in gram negative bacteria

    Directory of Open Access Journals (Sweden)

    Deepti Rawat

    2010-01-01

    Full Text Available Extended-spectrum ß-lactamases (ESBLs are a group of plasmid-mediated, diverse, complex and rapidly evolving enzymes that are posing a major therapeutic challenge today in the treatment of hospitalized and community-based patients. Infections due to ESBL producers range from uncomplicated urinary tract infections to life-threatening sepsis. Derived from the older TEM is derived from Temoniera, a patient from whom the strain was first isolated in Greece. ß-lactamases, these enzymes share the ability to hydrolyze third-generation cephalosporins and aztreonam and yet are inhibited by clavulanic acid. In addition, ESBL-producing organisms exhibit co-resistance to many other classes of antibiotics, resulting in limitation of therapeutic option. Because of inoculum effect and substrate specificity, their detection is also a major challenge. At present, however, organizations such as the Clinical and Laboratory Standards Institute (formerly the National Committee for Clinical Laboratory Standards provide guidelines for the detection of ESBLs in Klebsiella pneumoniae, K. oxytoca, Escherichia coli and Proteus mirabilis. In common to all ESBL-detection methods is the general principle that the activity of extended-spectrum cephalosporins against ESBL-producing organisms will be enhanced by the presence of clavulanic acid. Carbapenems are the treatment of choice for serious infections due to ESBL-producing organisms, yet carbapenem-resistant isolates have recently been reported. ESBLs represent an impressive example of the ability of gram-negative bacteria to develop new antibiotic-resistance mechanisms in the face of the introduction of new antimicrobial agents. Thus there is need for efficient infection-control practices for containment of outbreaks; and intervention strategies, e.g., antibiotic rotation to reduce further selection and spread of these increasingly resistant pathogens.

  4. The epidemiology and clinical features of melioidosis in Far North Queensland: Implications for patient management.

    Directory of Open Access Journals (Sweden)

    James D Stewart

    2017-03-01

    Full Text Available The epidemiology, clinical presentation and management of melioidosis vary around the world. It is essential to define the disease's local features to optimise its management.Between 1998 and 2016 there were 197 cases of culture confirmed melioidosis in Far North Queensland; 154 (78% presented in the December-April wet season. 145 (74% patients were bacteraemic, 58 (29% were admitted to the Intensive Care Unit and 27 (14% died; nine (33% of these deaths occurred within 48 hours of presentation. Pneumonia was the most frequent clinical finding, present in 101 (61% of the 166 with available imaging. A recognised risk factor for melioidosis (diabetes, hazardous alcohol use, chronic renal disease, chronic lung disease, immunosuppression or malignancy was present in 148 (91% of 162 patients with complete comorbidity data. Despite representing only 9% of the region's population, Aboriginal and Torres Strait Island (ATSI people comprised 59% of the cases. ATSI patients were younger than non-ATSI patients (median (interquartile range: 46 (38-56 years versus 59 (43-69 years (p<0.001 and had a higher case-fatality rate (22/117 (19% versus 5/80 (6.3% (p = 0.01. In the 155 patients surviving the initial intensive intravenous phase of treatment, eleven (7.1% had disease recurrence, despite the fact that nine (82% of these patients had received prolonged intravenous therapy. Recurrence was usually due to inadequate source control or poor adherence to oral eradication therapy. The case fatality rate declined from 12/44 (27% in the first five years of the study to 7/76 (9% in the last five (p = 0.009, reflecting national improvements in sepsis management.Melioidosis in Far North Queensland is a seasonal, opportunistic infection of patients with specific comorbidities. The ATSI population bear the greatest burden of disease. Although the case-fatality rate is declining, deaths frequently occur early after hospitalisation, reinforcing the importance of prompt

  5. Transmission Modes of Melioidosis in Taiwan

    Directory of Open Access Journals (Sweden)

    Pei-Tan Hsueh

    2018-02-01

    Full Text Available In Taiwan, melioidosis is an emerging disease that suddenly increased in the Er-Ren River Basin, beginning in 2005 and in the Zoynan region during 2008–2012, following a typhoon. Additionally, the disease sporadically increased in a geography-dependent manner in 2016. Subcutaneous inoculation, ingestion, and the inhalation of soil or water contaminated with Burkholderia pseudomallei are recognized as the transmission modes of melioidosis. The appearance of environmental B. pseudomallei positivity in northern, central and southern Taiwan is associated with disease prevalence (cases/population: 0.03/100,000 in the northern region, 0.29/100,000 in the central region and 1.98/100,000 in the southern region. However, melioidosis-clustered areas are confined to 5 to 7.5 km2 hot spots containing high-density populations, but B. pseudomallei-contaminated environments are located >5 km northwestern of the periphery of these hot spots. The observation that the concentration of B. pseudomallei-specific DNA in aerosols was positively correlated with the incidence of melioidosis and the appearance of a northwesterly wind in a hot spot indicated that airborne transmission had occurred in Taiwan. Moreover, the isolation rate in the superficial layers of a contaminated crop field in the northwest was correlated with PCR positivity in aerosols collected from the southeast over a two-year period. The genotype ST58 was identified by multilocus sequence typing in human and aerosol isolates. The genotype ST1001 has increased in prevalence but has been sporadically distributed elsewhere since 2016. These data indicate the transmission modes and environmental foci that support the dissemination of melioidosis are changing in Taiwan.

  6. Human melioidosis reported by ProMED.

    Science.gov (United States)

    Nasner-Posso, Katherinn Melissa; Cruz-Calderón, Stefania; Montúfar-Andrade, Franco E; Dance, David A B; Rodriguez-Morales, Alfonso J

    2015-06-01

    There are limited sources describing the global burden of emerging diseases. A review of human melioidosis reported by ProMED was performed and the reliability of the data retrieved assessed in comparison to published reports. The effectiveness of ProMED was evaluated as a source of epidemiological data by focusing on melioidosis. Using the keyword 'melioidosis' in the ProMED search engine, all of the information from the reports and collected data was reviewed using a structured form, including the year, country, gender, occupation, number of infected individuals, and number of fatal cases. One hundred and twenty-four entries reported between January 1995 and October 2014 were identified. A total of 4630 cases were reported, with death reported in 505 cases, suggesting a misleadingly low overall case fatality rate (CFR) of 11%. Of 20 cases for which the gender was reported, 12 (60%) were male. Most of the cases were reported from Australia, Thailand, Singapore, Vietnam, and Malaysia, with sporadic reports from other countries. Internet-based reporting systems such as ProMED are useful to gather information and synthesize knowledge on emerging infections. Although certain areas need to be improved, ProMED provided good information about melioidosis. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  7. The public health implications of melioidosis

    Directory of Open Access Journals (Sweden)

    Timothy J.J. Inglis

    Full Text Available Melioidosis, which is caused by the bacterium Burkholderia pseudomallei, is a potentially fatal tropical infection, little known outside its main endemic zone of Southeast Asia and northern Australia. Though it has received more attention in recent years on account of its claimed suitability as a biological weapon agent, the principal threat from melioidosis is a result of naturally occurring events. Occasional case clusters, sporadic cases outside the known endemic zone and infections in unusual demographic groups highlight a changing epidemiology. As melioidosis is the result of an environmental encounter and not person-to-person transmission, subtle changes in its epidemiology indicate a role environmental factors, such as man-made disturbances of soil and surface water. These have implications for travel, occupational and tropical medicine and in particular for risk assessment and prevention. Practical problems with definitive laboratory diagnosis, antibiotic treatment and the current lack of a vaccine underline the need for prevention through exposure avoidance and other environmental health measures. It is likely that the increasing population burden of the tropical zone and extraction of resources from the humid tropics will increase the prevalence of melioidosis. Climate change-driven extreme weather events will both increase the prevalence of infection and gradually extend its main endemic zone.

  8. Antimicrobial-resistant Gram-negative bacteria in febrile neutropenic patients with cancer: current epidemiology and clinical impact.

    Science.gov (United States)

    Trecarichi, Enrico M; Tumbarello, Mario

    2014-04-01

    In the recent years, several studies involving cancer patients have demonstrated a clear trend in the epidemiology of bacterial infections showing a shift in the prevalence from Gram-positive to Gram-negative bacteria and the extensive emergence of antimicrobial-resistant strains among Gram-negatives isolated from the blood. The aim of this systematic review was to examine the recent trends in epidemiology and antimicrobial resistance in Gram-negatives recovered from neutropenic cancer patients, with particular emphasis on the impact of antimicrobial resistance on the clinical outcome of severe infections caused by such microorganisms. Overall, from 2007 to date, the rate of Gram-negative bacteria recovery ranged from 24.7 to 75.8% (mean 51.3%) in cancer patient cohorts. Escherichia coli represented the most common species (mean frequency of isolation 32.1%) among the Gram-negatives, followed by Pseudomonas aeruginosa (mean frequency of isolation 20.1%). An increasing frequency of Acinetobacter spp. and Stenotrophomonas maltophilia was also reported. Increased rates of multidrug-resistant Gram-negative strains have been highlighted among Enterobacteriaceae and nonfermenting Gram-negative rods, despite discontinuation of fluoroquinolone-based antibacterial prophylaxis for neutropenic patients. In addition, antimicrobial resistance and/or the inadequacy of empirical antibiotic treatment have been frequently linked to a worse outcome in cancer patients with bloodstream infections caused by Gram-negative isolates. Sound knowledge of the local distribution of pathogens and their susceptibility patterns and prompt initiation of effective antimicrobial treatment for severe infections caused by Gram-negative bacteria are essential in cancer patients.

  9. Procalcitonin, C-reactive protein and serum lactate dehydrogenase in the diagnosis of bacterial sepsis, SIRS and systemic candidiasis.

    Science.gov (United States)

    Miglietta, Fabio; Faneschi, Maria Letizia; Lobreglio, Giambattista; Palumbo, Claudio; Rizzo, Adriana; Cucurachi, Marco; Portaccio, Gerolamo; Guerra, Francesco; Pizzolante, Maria

    2015-09-01

    The aim of this study was to evaluate procalcitonin (PCT), C-reactive protein (CRP), platelet count (PLT) and serum lactate dehydrogenase (LDH) as early markers for diagnosis of SIRS, bacterial sepsis and systemic candidiasis in intensive care unit (ICU) patients. Based on blood culture results, the patients were divided into a sepsis group (70 patients), a SIRS group (42 patients) and a systemic candidiasis group (33 patients). PCT, CRP, LDH and PLT levels were measured on day 0 and on day 2 from the sepsis symptom onset. PCT levels were higher in Gram negative sepsis than those in Gram positive sepsis, although the P value between the two subgroups is not significant (P=0.095). Bacterial sepsis group had higher PCT and CRP levels compared with the systemic candidiasis group, whereas PLT and LDH levels showed similar levels in these two subgroups. The AUC for PCT (AUC: 0.892, P candidiasis groups (P=0.093 N.S.). In conclusion, PCT can be used as a preliminary marker in the event of clinical suspicion of systemic candidiasis; however, low PCT levels (candidiasis and SIRS groups.

  10. The target of daptomycin is absent from Escherichia coli and other gram-negative pathogens.

    Science.gov (United States)

    Randall, Christopher P; Mariner, Katherine R; Chopra, Ian; O'Neill, Alex J

    2013-01-01

    Antistaphylococcal agents commonly lack activity against Gram-negative bacteria like Escherichia coli owing to the permeability barrier presented by the outer membrane and/or the action of efflux transporters. When these intrinsic resistance mechanisms are artificially compromised, such agents almost invariably demonstrate antibacterial activity against Gram negatives. Here we show that this is not the case for the antibiotic daptomycin, whose target appears to be absent from E. coli and other Gram-negative pathogens.

  11. Effectiveness of oral antibiotics for definitive therapy of Gram-negative bloodstream infections.

    Science.gov (United States)

    Kutob, Leila F; Justo, Julie Ann; Bookstaver, P Brandon; Kohn, Joseph; Albrecht, Helmut; Al-Hasan, Majdi N

    2016-11-01

    There is paucity of data evaluating intravenous-to-oral antibiotic switch options for Gram-negative bloodstream infections (BSIs). This retrospective cohort study examined the effectiveness of oral antibiotics for definitive treatment of Gram-negative BSI. Patients with Gram-negative BSI hospitalised for antibiotics were included in this study. The cohort was stratified into three groups based on bioavailability of oral antibiotics prescribed (high, ≥95%; moderate, 75-94%; and low, antibiotics were prescribed to 106, 179 and 77 patients, respectively, for definitive therapy of Gram-negative BSI. Mean patient age was 63 years, 217 (59.9%) were women and 254 (70.2%) had a urinary source of infection. Treatment failure rates were 2%, 12% and 14% in patients receiving oral antibiotics with high, moderate and low bioavailability, respectively (P = 0.02). Risk of treatment failure in the multivariate Cox model was higher in patients receiving antibiotics with moderate [adjusted hazard ratio (aHR) = 5.9, 95% CI 1.6-38.5; P = 0.005] and low bioavailability (aHR = 7.7, 95% CI 1.9-51.5; P = 0.003) compared with those receiving oral antimicrobial agents with high bioavailability. These data demonstrate the effectiveness of oral antibiotics with high bioavailability for definitive therapy of Gram-negative BSI. Risk of treatment failure increases as bioavailability of the oral regimen declines. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  12. Widespread Fosfomycin Resistance in Gram-Negative Bacteria Attributable to the Chromosomal fosA Gene

    Directory of Open Access Journals (Sweden)

    Ryota Ito

    2017-08-01

    Full Text Available Fosfomycin is a decades-old antibiotic which is being revisited because of its perceived activity against many extensively drug-resistant Gram-negative pathogens. FosA proteins are Mn2+ and K+-dependent glutathione S-transferases which confer fosfomycin resistance in Gram-negative bacteria by conjugation of glutathione to the antibiotic. Plasmid-borne fosA variants have been reported in fosfomycin-resistant Escherichia coli strains. However, the prevalence and distribution of fosA in other Gram-negative bacteria are not known. We systematically surveyed the presence of fosA in Gram-negative bacteria in over 18,000 published genomes from 18 Gram-negative species and investigated their contribution to fosfomycin resistance. We show that FosA homologues are present in the majority of genomes in some species (e.g., Klebsiella spp., Enterobacter spp., Serratia marcescens, and Pseudomonas aeruginosa, whereas they are largely absent in others (e.g., E. coli, Acinetobacter baumannii, and Burkholderia cepacia. FosA proteins in different bacterial pathogens are highly divergent, but key amino acid residues in the active site are conserved. Chromosomal fosA genes conferred high-level fosfomycin resistance when expressed in E. coli, and deletion of chromosomal fosA in S. marcescens eliminated fosfomycin resistance. Our results indicate that FosA is encoded by clinically relevant Gram-negative species and contributes to intrinsic fosfomycin resistance.

  13. Moraxella catarrhalis sepsis

    Directory of Open Access Journals (Sweden)

    Paola Gualdi

    2008-06-01

    Full Text Available Moraxella catarrhalis is a Gram-negative aerobic diplococcus, commensal of the oro-pharingeal cavity, actually playing an emerging role in the upper respiratory tract infections together with Streptococcus pneumoniae and Haemophilus influenzae. This study reports the case of a twoyearold child who was admitted into hospital with fever, headache and vomit. The chest radiograph showed signs of basal lung involvementmaking the clinical suspicion of bacterial infectionlikely. From blood culture a Moraxella catarrhalis strain was isolated. In young children M. catarrhalis is known to cause otitis media and sinusitis, but only rarely bacteremia. In this case the child showed a clinical picture of lung infection and consequent sepsis due to M. catarrhalis.

  14. Emergence of pediatric melioidosis in Siem Reap, Cambodia.

    Science.gov (United States)

    Pagnarith, Yos; Kumar, Varun; Thaipadungpanit, Janjira; Wuthiekanun, Vanaporn; Amornchai, Premjit; Sin, Lina; Day, Nicholas P; Peacock, Sharon J

    2010-06-01

    We describe the first cases of pediatric melioidosis in Cambodia. Thirty-nine cases were diagnosed at the Angkor Hospital for Children, Siem Reap, between October 2005 and December 2008 after the introduction of microbiology capabilities. Median age was 7.8 years (range = 1.6-16.2 years), 15 cases were male (38%), and 4 cases had pre-existing conditions that may have pre-disposed the patient to melioidosis. Infection was localized in 27 cases (69%) and disseminated in 12 cases (31%). Eleven cases (28%) were treated as outpatients, and 28 (72%) cases were admitted. Eight children (21%) died a median of 2 days after admission; seven deaths were attributable to melioidosis, all of which occurred in children receiving suboptimal antimicrobial therapy and before bacteriological culture results were available. Our findings indicate the need for heightened awareness of melioidosis in Cambodia, and they have led us to review microbiology procedures and antimicrobial prescribing of suspected and confirmed cases.

  15. Raman Spectroscopy of Xylitol Uptake and Metabolism in Gram-Positive and Gram-Negative Bacteria▿

    Science.gov (United States)

    Palchaudhuri, Sunil; Rehse, Steven J.; Hamasha, Khozima; Syed, Talha; Kurtovic, Eldar; Kurtovic, Emir; Stenger, James

    2011-01-01

    Visible-wavelength Raman spectroscopy was used to investigate the uptake and metabolism of the five-carbon sugar alcohol xylitol by Gram-positive viridans group streptococcus and the two extensively used strains of Gram-negative Escherichia coli, E. coli C and E. coli K-12. E. coli C, but not E. coli K-12, contains a complete xylitol operon, and the viridans group streptococcus contains an incomplete xylitol operon used to metabolize the xylitol. Raman spectra from xylitol-exposed viridans group streptococcus exhibited significant changes that persisted even in progeny grown from the xylitol-exposed mother cells in a xylitol-free medium for 24 h. This behavior was not observed in the E. coli K-12. In both viridans group streptococcus and the E. coli C derivative HF4714, the metabolic intermediates are stably formed to create an anomaly in bacterial normal survival. The uptake of xylitol by Gram-positive and Gram-negative pathogens occurs even in the presence of other high-calorie sugars, and its stable integration within the bacterial cell wall may discontinue bacterial multiplication. This could be a contributing factor for the known efficacy of xylitol when taken as a prophylactic measure to prevent or reduce occurrences of persistent infection. Specifically, these bacteria are causative agents for several important diseases of children such as pneumonia, otitis media, meningitis, and dental caries. If properly explored, such an inexpensive and harmless sugar-alcohol, alone or used in conjunction with fluoride, would pave the way to an alternative preventive therapy for these childhood diseases when the causative pathogens have become resistant to modern medicines such as antibiotics and vaccine immunotherapy. PMID:21037297

  16. Combinatorial events of insertion sequences and ICE in Gram-negative bacteria.

    Science.gov (United States)

    Toleman, Mark A; Walsh, Timothy R

    2011-09-01

    The emergence of antibiotic and antimicrobial resistance in Gram-negative bacteria is incremental and linked to genetic elements that function in a so-called 'one-ended transposition' manner, including ISEcp1, ISCR elements and Tn3-like transposons. The power of these elements lies in their inability to consistently recognize one of their own terminal sequences, while recognizing more genetically distant surrogate sequences. This has the effect of mobilizing the DNA sequence found adjacent to their initial location. In general, resistance in Gram-negatives is closely linked to a few one-off events. These include the capture of the class 1 integron by a Tn5090-like transposon; the formation of the 3' conserved segment (3'-CS); and the fusion of the ISCR1 element to the 3'-CS. The structures formed by these rare events have been massively amplified and disseminated in Gram-negative bacteria, but hitherto, are rarely found in Gram-positives. Such events dominate current resistance gene acquisition and are instrumental in the construction of large resistance gene islands on chromosomes and plasmids. Similar combinatorial events appear to have occurred between conjugative plasmids and phages constructing hybrid elements called integrative and conjugative elements or conjugative transposons. These elements are beginning to be closely linked to some of the more powerful resistance mechanisms such as the extended spectrum β-lactamases, metallo- and AmpC type β-lactamases. Antibiotic resistance in Gram-negative bacteria is dominated by unusual combinatorial mistakes of Insertion sequences and gene fusions which have been selected and amplified by antibiotic pressure enabling the formation of extended resistance islands. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  17. Prevalence of Gram-negative Pathogens and their antimicrobial ...

    African Journals Online (AJOL)

    The present study was conducted to find out the prevalence and spectrum of Gram negative pathogens causing bacterial meningitis and their antimicrobial susceptibility pattern in a tertiary care hospital. The cerebrospinal fluid (CSF) (3-5 ml) was collected from 638 admitted children clinically suspected of septic meningitis.

  18. Sinus surgery postpones chronic gram-negative lung infection

    DEFF Research Database (Denmark)

    Alanin, M C; Aanaes, K; Høiby, N

    2016-01-01

    Background: In patients with cystic fibrosis (CF) the sinuses are a bacterial reservoir for Gram-negative bacteria (GNB). From the sinuses the GNB can repeatedly migrate to the lungs. In a one-year follow-up study, endoscopic sinus surgery (ESS) with adjuvant therapy reduced the frequency...

  19. Black-pigmented gram-negative anaerobes in endodontic infections.

    Science.gov (United States)

    Haapasalo, M

    1993-03-01

    Necrotic dental root canal infections are polymicrobial infections dominated by anaerobic bacteria. The number of different species in one canal is usually low, approx. 4-7 species. The species isolated most frequently belong to the genera Prevotella, Porphyromonas, Fusobacterium, Peptostreptococcus, Eubacterium and Streptococcus. The frequency of isolation of black-pigmented Gram-negative anaerobes in endodontic infections varies from 25% to > 50%. Pr. intermedia is the most commonly found pigmented species, followed by Pr. denticola and two Porphyromonas species, P. gingivalis and P. endodontalis. Several studies have shown that P. gingivalis and P. endodontalis are closely related to the presence of acute symptoms in endodontic infections, whereas other black-pigmented Gram-negative anaerobes are not. However, several other species may also be involved in acute infections. Moreover, Porphyromonas species have occasionally been isolated from cases with no symptoms. Although Porphyromonas spp. are clearly related to symptoms at the beginning of therapy, they are not important for the prognosis of the treatment.

  20. Breaking barriers: expansion of the use of endolysins as novel antibacterials against Gram-negative bacteria.

    Science.gov (United States)

    Briers, Yves; Lavigne, Rob

    2015-01-01

    The emergence and spread of antibiotic-resistant bacteria drives the search for novel classes of antibiotics to replenish our armamentarium against bacterial infections. This is particularly critical for Gram-negative pathogens, which are intrinsically resistant to many existing classes of antibiotics due to the presence of a protective outer membrane. In addition, the antibiotics development pipeline is mainly oriented to Gram-positive pathogens such as methicillin-resistant Staphylococcus aureus. A promising novel class of antibacterials is endolysins. These enzymes encoded by bacterial viruses hydrolyze the peptidoglycan layer with high efficiency, resulting in abrupt osmotic lysis and cell death. Their potential as novel antibacterials to treat Gram-positive bacteria has been extensively demonstrated; however, the Gram-negative outer membrane has presented a formidable barrier for the use of endolysins against Gram-negatives until recently. This review reports on the most recent advances in the development of endolysins to kill Gram-negative species with a special focus on endolysin-engineered Artilysins(®).

  1. Inhaled Antibiotics for Gram-Negative Respiratory Infections

    Science.gov (United States)

    Fraidenburg, Dustin R.; Scardina, Tonya

    2016-01-01

    SUMMARY Gram-negative organisms comprise a large portion of the pathogens responsible for lower respiratory tract infections, especially those that are nosocomially acquired, and the rate of antibiotic resistance among these organisms continues to rise. Systemically administered antibiotics used to treat these infections often have poor penetration into the lung parenchyma and narrow therapeutic windows between efficacy and toxicity. The use of inhaled antibiotics allows for maximization of target site concentrations and optimization of pharmacokinetic/pharmacodynamic indices while minimizing systemic exposure and toxicity. This review is a comprehensive discussion of formulation and drug delivery aspects, in vitro and microbiological considerations, pharmacokinetics, and clinical outcomes with inhaled antibiotics as they apply to disease states other than cystic fibrosis. In reviewing the literature surrounding the use of inhaled antibiotics, we also highlight the complexities related to this route of administration and the shortcomings in the available evidence. The lack of novel anti-Gram-negative antibiotics in the developmental pipeline will encourage the innovative use of our existing agents, and the inhaled route is one that deserves to be further studied and adopted in the clinical arena. PMID:27226088

  2. Resistance trends in gram-negative bacteria: surveillance results from two Mexican hospitals, 2005–2010

    Directory of Open Access Journals (Sweden)

    Morfin-Otero Rayo

    2012-06-01

    Full Text Available Abstract Background Hospital-acquired infections caused by multiresistant gram-negative bacteria are difficult to treat and cause high rates of morbidity and mortality. The analysis of antimicrobial resistance trends of gram-negative pathogens isolated from hospital-acquired infections is important for the development of antimicrobial stewardship programs. The information obtained from antimicrobial resistant programs from two hospitals from Mexico will be helpful in the selection of empiric therapy for hospital-acquired gram-negative infections. Findings Two thousand one hundred thirty two gram-negative bacteria collected between January 2005 and December 2010 from hospital-acquired infections occurring in two teaching hospitals in Mexico were evaluated. Escherichia coli was the most frequently isolated gram-negative bacteria, with >50% of strains resistant to ciprofloxacin and levofloxacin. Klebsiella spp. showed resistance rates similar to Escherichia coli for ceftazidime (33.1% vs 33.2%, but exhibited lower rates for levofloxacin (18.2% vs 56%. Of the samples collected for the third most common gram-negative bacteria, Pseudomonas aeruginosa, >12.8% were resistant to the carbapenems, imipenem and meropenem. The highest overall resistance was found in Acinetobacter spp. Enterobacter spp. showed high susceptibility to carbapenems. Conclusions E. coli was the most common nosocomial gram-negative bacilli isolated in this study and was found to have the second-highest resistance to fluoroquinolones (>57.9%, after Acinetobacter spp. 81.2%. This finding represents a disturbing development in a common nosocomial and community pathogen.

  3. A Synthetic Dual Drug Sideromycin Induces Gram-Negative Bacteria To Commit Suicide with a Gram-Positive Antibiotic.

    Science.gov (United States)

    Liu, Rui; Miller, Patricia A; Vakulenko, Sergei B; Stewart, Nichole K; Boggess, William C; Miller, Marvin J

    2018-05-10

    Many antibiotics lack activity against Gram-negative bacteria because they cannot permeate the outer membrane or suffer from efflux and, in the case of β-lactams, are degraded by β-lactamases. Herein, we describe the synthesis and studies of a dual drug conjugate (1) of a siderophore linked to a cephalosporin with an attached oxazolidinone. The cephalosporin component of 1 is rapidly hydrolyzed by purified ADC-1 β-lactamase to release the oxazolidinone. Conjugate 1 is active against clinical isolates of Acinetobacter baumannii as well as strains producing large amounts of ADC-1 β-lactamase. Overall, the results are consistent with siderophore-mediated active uptake, inherent activity of the delivered dual drug, and in the presence of β-lactamases, intracellular release of the oxazolidinone upon cleavage of the cephalosporin to allow the freed oxazolidinone to inactivate its target. The ultimate result demonstrates that Gram-positive oxazolidinone antibiotics can be made to be effective against Gram-negative bacteria by β-lactamase triggered release.

  4. [Influence of serious infections due to Gram-negative bacteria on the hospital economy].

    Science.gov (United States)

    Martínez, B; Gómez, J; Gómez Vargas, J; Guerra, B; Ruiz Gómez, J; Simarro, E; Baños, V; Canteras, M; Valdes, M

    2000-12-01

    Nosocomial infections due to Gram-negative bacteria are very important since they are associated with high morbidity and high hospital costs. A prospective study of 250 inpatients was carried out, 200 of whom had Gram-negative bacterial infections. Patients were divided into groups of 50 according to the localization of the infection (urinary, surgical wound, respiratory tract and bacteremia), with a control group of 50 patients with similar characteristics but no infection. We calculated the cost for the different groups by multiplying the average length of hospital stay in days by the daily cost of the stay. Significant differences were observed in the average length of stay per patient according to the type of infection and how it was acquired. In terms of cost, nosocomial infection due to Gram-negative bacteria was 1,049,139 pesetas more expensive than community-acquired infection. The cost of the stay for patients with postsurgical infection due to Gram-negative bacteria was 1,108, 252 pesetas more expensive than for the group of control patients. Nosocomial infection due to Gram-negative bacteria is associated with a prolongation in hospital stay of 9 to 28 days, which is the factor that most reflects the cost that can be attributed to nosocomial infection. Consensual and protocolized measures which allow for better clinical management need to be developed.

  5. Changing epidemiology of central venous catheter-related bloodstream infections: increasing prevalence of Gram-negative pathogens.

    Science.gov (United States)

    Marcos, Miguel; Soriano, Alex; Iñurrieta, Amaia; Martínez, José A; Romero, Alberto; Cobos, Nazaret; Hernández, Cristina; Almela, Manel; Marco, Francesc; Mensa, Josep

    2011-09-01

    Gram-positive microorganisms have been the predominant pathogens in central venous catheter-related bloodstream infections (CRBSIs). Recent guidelines recommend empirical therapy according to this and restrict coverage for Gram-negatives to specific circumstances. This study aimed to analyse the epidemiological changes in CRBSIs over the 1991-2008 period and to analyse predictors of Gram-negative CRBSIs. A prospectively collected cohort of patients with confirmed CRBSIs was analysed. Strains isolated and antimicrobial susceptibility, as well as clinical and demographic variables were recorded. Differences observed during the study period were analysed by means of a χ² trend test and factors associated with Gram-negative CRBSIs by means of multivariable analysis. Between 1991 and 2008, 1129 episodes of monomicrobial CRBSIs were recorded. There was an increase in the incidence of CRBSIs, from 0.10 (1991-92) to 0.31 (2007-08) episodes/1000 patient-days. A significant increase in the number of Gram-negative strains among the total isolates was also found, from 3 (4.7%) in 1991-92 to 70 (40.23%) in 2007-08, with a parallel decrease in the percentage of Gram-positives. Solid organ transplantation, prior use of penicillins and hospital stay longer than 11 days were independently associated with a significantly higher risk of Gram-negative CRBSIs, while cirrhosis, diabetes and use of quinolones were associated with a higher risk of Gram-positives. Gram-negative strains are an increasing cause of CRBSIs, reaching a prevalence of 40% in the 2007-08 period in our hospital. If this trend is confirmed in other centres, a broad-spectrum empirical therapy should be considered in managing these infections.

  6. Community-acquired multidrug-resistant Gram-negative bacterial infective endocarditis.

    Science.gov (United States)

    Naha, Sowjanya; Naha, Kushal; Acharya, Vasudev; Hande, H Manjunath; Vivek, G

    2014-08-05

    We describe two cases of bacterial endocarditis secondary to multidrug-resistant Gram-negative organisms. In both cases, the diagnosis was made in accordance with the modified Duke's criteria and confirmed by histopathological analysis. Furthermore, in both instances there were no identifiable sources of bacteraemia and no history of contact with hospital or other medical services prior to the onset of symptoms. The patients were managed in similar fashion with prolonged broad-spectrum antibiotic therapy and surgical intervention and made complete recoveries. These cases highlight Gram-negative organisms as potential agents for endocarditis, as well as expose the dissemination of such multidrug-resistant bacteria into the community. The application of an integrated medical and surgical approach and therapeutic dilemmas encountered in managing these cases are described. 2014 BMJ Publishing Group Ltd.

  7. Gram-negative folliculitis. A rare problem or is it underdiagnosed? Case report and literature review

    Directory of Open Access Journals (Sweden)

    Sierra-Téllez Daniela, Ponce-Olivera Rosa María, Tirado-Sánchez Andrés

    2011-07-01

    Full Text Available AbstractGram-negative folliculitis may be the result of prolonged antibacterial treatments in patients with acne and rosacea. It is caused by alteration of facial skin flora and the nasal mucous, a decrease of Gram-positive bacteria and a proliferation of Gram-negative bacteria (for example Escherichia coli, Pseudomonas aeruginosa, Serratia marcescens, Klebsiella sp. and Proteus mirabilis. It should be considered in patients with acne who have not had a clinical improvement after 3-6 months of treatment with tetracyclines. The disease is underestimated, probably because bacteriological studies are rarely requested and the increased use of oral isotretinoin for acne management. One of the most effective treatments for Gram-negative folliculitis is oral isotretinoin (0.5-1 mg / kg / day for 4-5 months. We report the case of Gram negative folliculitis successfully treated with oral isotretinoin.

  8. Challenges in the Prevention of Coagulase-Negative Staphylococcal Sepsis in Neonates

    NARCIS (Netherlands)

    V. Hira (Vishal)

    2013-01-01

    textabstractCoagulase-negative staphylococci (CoNS) are the leading cause of late-onset sepsis (LOS) worldwide. As antibiotic resistance is dramatically increasing in these organisms, prevention is becoming more and more important. CoNS that are isolated from blood cultures of neonates with LOS on

  9. Rapid and cost-effective identification and antimicrobial susceptibility testing in patients with Gram-negative bacteremia directly from blood-culture fluid.

    Science.gov (United States)

    Sakarikou, Christina; Altieri, Anna; Bossa, Maria Cristina; Minelli, Silvia; Dolfa, Camilla; Piperno, Micol; Favalli, Cartesio

    2018-03-01

    Rapid pathogen identification (ID) and antimicrobial susceptibility testing (AST) in bacteremia cases or sepsis could improve patient prognosis. Thus, it is important to provide timely reports, which make it possible for clinicians to set up appropriate antibiotic therapy during the early stages of bloodstream infection (BSI). This study evaluates an in-house microbiological protocol for early ID as well as AST on Gram negative bacteria directly from positive monomicrobial and polymicrobial blood cultures (BCs). A total of 102 non-duplicated positive BCs from patients with Gram-negative bacteremia were tested. Both IDs and ASTs were performed from bacterial pellets extracted directly from BCs using our protocol, which was applied through the combined use of a MALDI-TOF MS and Vitek2 automated system. The results of our study showed a 100% agreement in bacterial ID and 98.25% categorical agreement in AST when compared to those obtained by routine conventional methods. We recorded only a 0.76% minor error (mE), 0.76% major error (ME) and a 0.20% very major error (VME). Moreover, the turnaround time (TAT) regarding the final AST report was significantly shortened (ΔTAT = 8-20 h, p patient management, by early and appropriate antimicrobial treatment and could potentially optimize antimicrobial stewardship programs. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Epidemiology of infections caused by multiresistant gram-negatives: ESBLs, MBLs, panresistant strains.

    Science.gov (United States)

    Rossolini, Gian Maria; Mantengoli, Elisabetta; Docquier, Jean-Denis; Musmanno, Rosa Anna; Coratza, Grazietta

    2007-07-01

    Microbial drug resistance is a growing problem of global magnitude. In gram-negative pathogens, the most important resistance problems are encountered in Enterobacteriaceae, Pseudomonas aeruginosa and Acinetobacter, with increasing trends observed for all major anti-gram-negative agents (beta-lactams, fluoroquinolones and aminoglycosides). A matter of major concern is the emergence of new beta-lactamases capable of degrading the expanded-spectrum cephalosporins and/or carbapenems, such as the extended-spectrum beta-lactamases (ESBLs) and the carbapenemases. These beta-lactamase genes are often associated with resistance determinants to non-beta-lactam agents (e.g. aminoglycosides and fluoroquinolones), and strains producing ESBLs or carbapenemases often exhibit complex multidrug resistant phenotypes and sometimes are panresistant. The problem is worsened by the dearth of new agents active on multidrug-resistant Gram-negatives in the pipeline. The importance to develop better strategies to control resistance is underscored.

  11. STUDY ON SURGICAL SITE INFECTIONS CAUSED BY ESBL PRODUCING GRAM NEGATIVE BACTERIA

    Directory of Open Access Journals (Sweden)

    Rambabu

    2015-09-01

    Full Text Available Surgical site infections have been a major problem, because of the emergence of drug resistant bacteria, in particular B - lactamase producing bacteria. Extended spectrum beta lactamase producing gram negative organisms pose a great challenge in treatment o f SSI present study is aimed at determining multiple drug resistance in gram negative bacteria & to find out ESBL producers, in correlation with treatment outcome. A total of 120 wound infected cases were studied. Staphylococcus aureus was predominant bact erium - 20.Among gram negative bacteria, Pseudomonas species is predominant (14 followed by Escherichia coli (13 , Klebsiella species (12 , Proteus (9 Citrobacter (4 Providencia (2 & Acinetobacter species (2 . Out of 56 gramnegative bacteria isolated, 20 were i dentified as ESBL producers, which was statistically significant. Delay in wound healing correlated with infection by ESBL producers, which alarms the need of abstinence from antibiotic abuse

  12. Quorum sensing in gram-negative bacteria

    DEFF Research Database (Denmark)

    Wu, H.; Song, Z.J.; Høiby, N.

    2004-01-01

    Bacteria can communicate with each other by means of signal molecules to coordinate the behavior of the entire community, and the mechanism is referred to as quorum sensing (QS). Signal systems enable bacteria to sense the size of their densities by monitoring the concentration of the signal...... molecules. Among Gram-negative bacteria N-acyl-L-homoserine lactone (acyl-HSL)-dependent quorum sensing systems are particularly widespread. These systems are used to coordinate expression of phenotypes that are fundamental to the interaction of bacteria with each other and with their environment...

  13. Intrinsic, adaptive and acquired antimicrobial resistance in Gram-negative bacteria.

    Science.gov (United States)

    Arzanlou, Mohsen; Chai, Wern Chern; Venter, Henrietta

    2017-02-28

    Gram-negative bacteria are responsible for a large proportion of antimicrobial-resistant infections in humans and animals. Among this class of bacteria are also some of the most successful environmental organisms. Part of this success is their adaptability to a variety of different niches, their intrinsic resistance to antimicrobial drugs and their ability to rapidly acquire resistance mechanisms. These mechanisms of resistance are not exclusive and the interplay of several mechanisms causes high levels of resistance. In this review, we explore the molecular mechanisms underlying resistance in Gram-negative organisms and how these different mechanisms enable them to survive many different stress conditions. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  14. Organo-Selenium Coatings Inhibit Gram-Negative and Gram-Positive Bacterial Attachment to Ophthalmic Scleral Buckle Material.

    Science.gov (United States)

    Tran, Phat; Arnett, Avery; Jarvis, Courtney; Mosley, Thomas; Tran, Khien; Hanes, Rob; Webster, Dan; Mitchell, Kelly; Dominguez, Leo; Hamood, Abdul; Reid, Ted W

    2017-09-01

    Biofilm formation is a problem for solid and sponge-type scleral buckles. This can lead to complications that require removal of the buckle, and result in vision loss due to related ocular morbidity, primarily infection, or recurrent retinal detachment. We investigate the ability of a covalent organo-selenium coating to inhibit biofilm formation on a scleral buckle. Sponge and solid Labtican brand scleral buckles were coated with organo-selenium coupled to a silyation reagent. Staphylococcus aureus biofilm formation was monitored by a standard colony-forming unit assay and the confocal laser scanning microscopy, while Pseudomonas aeruginosa biofilm formation was examined by scanning electron microscopy. Stability studies were done, by soaking in phosphate buffer saline (PBS) at room temperature for 2 months. Toxicity against human corneal epithelial cell was examined by growing the cells in the presence of organo-selenium-coated scleral buckles. The organo-selenium coating inhibited biofilm formation by gram-negative and gram-positive bacteria. The buckle coatings also were shown to be fully active after soaking in PBS for 2 months. The organo-selenium coatings had no effect on the viability of human corneal epithelial cells. Organo-selenium can be used to covalently coat a scleral buckle, which is stable and inhibits biofilm formation for gram-negative and gram-positive bacteria. The organo-selenium buckle coating was stable and nontoxic to cell culture. This technology provides a means to inhibit bacterial attachment to devices attached to the eye, without damage to ocular cells.

  15. [Diagnostic and therapeutic management of Gram-negative infections].

    Science.gov (United States)

    Bassetti, Matteo; Repetto, Ernestina

    2008-04-01

    Among Gram negative bacteria, Pseudomonas aeruginosa, the extended spectrum beta-lactamases (ESBL)-producing strains, Acinetobacter spp, in particular the multiresistant Acinetobacter baumannii, and Stenotrophomonas maltophilia are the most implicated micrororganisms in the ever more increasing problem of bacterial resistance. Possible solutions have to be searched, on one hand, in the use of new drugs but, on the other hand, in the re-evaluation of those already available drugs, possibly considering a new role for old drugs such as colistine and fosfomycin. Concerning ESBL-producing strains, the most recent data provided by EARSS report, in Italy, an incidence rate of 10-25 percent. The insurgence of an infection sustained by an ESBL+ve strain is strictly related to some well known risk factors, like the hospital stay itself, the disease severity, the length of stay in ICU, intubation and mechanical ventilation, catheterization, urinary or artery, and the past exposure to antibiotics. The raise in ESBL producing strains is closely related to the increasing use of cephalosporins. In the setting of a Gram negative infection, the combination therapy guarantees a higher coverage by reducing insurgence of possible resistance mechanisms, possibly resulting synergistic, and allowing a de-escalation therapy, although to this latter other problems, such as tolerability, costs and compliance, can be related. Another basic aspect to take into account of, in order to achieve the maximal efficacy of the antibiotic treatment, is the right dosage. In the idea to look for the best approach for the antibiotic treatment of a severe infection in a hospital setting, when a Gram negative aetiology is implicated, it can be possibly presumed that the right way consists in avoiding inappropriate antibiotic therapies, making therapeutic choices based on guidelines resulted from local epidemiological data, initiating the therapy promptly, avoiding excessive use of antibiotics, possibly

  16. Bacteremias in liver transplant recipients: shift toward gram-negative bacteria as predominant pathogens.

    Science.gov (United States)

    Singh, Nina; Wagener, Marilyn M; Obman, Asia; Cacciarelli, Thomas V; de Vera, Michael E; Gayowski, Timothy

    2004-07-01

    During the 1990s, gram-positive bacteria emerged as major pathogens after liver transplantation. We sought to determine whether the pathogens associated with bacteremias in liver transplant recipients have changed. Patients included 233 liver transplant recipients transplanted between 1989 and 2003. The proportion of all infections due to bacteremias increased significantly over time (P gram-negatives increased from 25% in the period of 1989-1993 to 51.8% in 1998-03, that of gram-positive bacteria decreased from 75% in the period of 1989-93 to 48.2% in the period of 1998-2003. Methicillin-resistant Staphylococcus aureus (MRSA), Klebsiella pneumoniae, and Pseudomonas aeruginosa were the most frequent pathogens in bacteremic patients. The incidence of bacteremias due to MRSA and Pseudomonas aeruginosa has remained unchanged (P gram-negative bacteria, particularly Klebsiella pneumoniae has increased (P =.02). Klebsiella pneumoniae isolates in the current quartile were not clonally related. In conclusion, bacteremias as a proportion of all infections in liver transplant recipients have increased significantly over time, due in part to a decline in infections due to other major pathogens, e.g., fungi, primarily Candida species, and CMV. Gram-negative bacteria have emerged as predominant pathogens in bacteremic liver transplant recipients.

  17. Physico-Chemical-Managed Killing of Penicillin-Resistant Static and Growing Gram-Positive and Gram-Negative Vegetative Bacteria

    Science.gov (United States)

    Richmond, Robert Chaffee (Inventor); Schramm, Jr., Harry F. (Inventor); Defalco, Francis G. (Inventor); Farris, III, Alex F. (Inventor)

    2012-01-01

    Systems and methods for the use of compounds from the Hofmeister series coupled with specific pH and temperature to provide rapid physico-chemical-managed killing of penicillin-resistant static and growing Gram-positive and Gram-negative vegetative bacteria. The systems and methods represent the more general physico-chemical enhancement of susceptibility for a wide range of pathological macromolecular targets to clinical management by establishing the reactivity of those targets to topically applied drugs or anti-toxins.

  18. Prediction of lipoprotein signal peptides in Gram-negative bacteria

    DEFF Research Database (Denmark)

    Juncker, Agnieszka; Willenbrock, Hanni; Von Heijne, G.

    2003-01-01

    A method to predict lipoprotein signal peptides in Gram-negative Eubacteria, LipoP, has been developed. The hidden Markov model (HMM) was able to distinguish between lipoproteins (SPaseII-cleaved proteins), SPaseI-cleaved proteins, cytoplasmic proteins, and transmembrane proteins. This predictor ...

  19. Multidrug resistance in enteric and other gram-negative bacteria.

    Science.gov (United States)

    George, A M

    1996-05-15

    In Gram-negative bacteria, multidrug resistance is a term that is used to describe mechanisms of resistance by chromosomal genes that are activated by induction or mutation caused by the stress of exposure to antibiotics in natural and clinical environments. Unlike plasmid-borne resistance genes, there is no alteration or degradation of drugs or need for genetic transfer. Exposure to a single drug leads to cross-resistance to many other structurally and functionally unrelated drugs. The only mechanism identified for multidrug resistance in bacteria is drug efflux by membrane transporters, even though many of these transporters remain to be identified. The enteric bacteria exhibit mostly complex multidrug resistance systems which are often regulated by operons or regulons. The purpose of this review is to survey molecular mechanisms of multidrug resistance in enteric and other Gram-negative bacteria, and to speculate on the origins and natural physiological functions of the genes involved.

  20. Clinical, Bacteriologic, and Geographic Stratification of Melioidosis Emerges from the Sri Lankan National Surveillance Program.

    Science.gov (United States)

    Sathkumara, Harindra D; Merritt, Adam J; Corea, Enoka M; Krishnananthasivam, Shivankari; Natesan, Mohan; Inglis, Timothy J J; De Silva, Aruna Dharshan

    2018-02-01

    Melioidosis, a potentially fatal tropical infection, is said to be underdiagnosed in low-income countries. An increase in melioidosis cases in Sri Lanka allowed us to analyze the relationship among clinical outcome, bacteriology, epidemiology, and geography in the first 108 laboratory-confirmed cases of melioidosis from a nationwide surveillance program. The additional 76 cases of laboratory-confirmed melioidosis confirmed further associations between Burkholderia pseudomallei multilocus sequence typing (MLST) and infection phenotype; ST1137/unifocal bacteremic infection (χ 2 = 3.86, P national genotyping-supported melioidosis registry will improve melioidosis diagnosis, treatment, and prevention where underdiagnosis and mortality rates remain high.

  1. [Current aspects of the definition and diagnosis of sepsis and antibiotic resistance].

    Science.gov (United States)

    Brunkhorst, Frank M; Gastmeier, Petra; Abu Sin, Muna

    2018-05-01

    Hospital mortality of patients with secondary sepsis remains high at around 40%. Because of the methodological deficiencies of the definitions used so far, valid epidemiological data on secondary sepsis that allow for national and international comparisons are lacking. Since 2016, new clinical diagnostic tools that are also suitable for sepsis screening outside of intensive care units have been available. To counteract the high mortality of nosocomial sepsis, new approaches to the early identification of at-risk patients are needed. An adequate blood culture sampling rate and a high preanalytical quality should be established as a basis for quality assurance, especially in the field of nosocomial bloodstream infections; otherwise, there is a risk of surveillance bias. Data from laboratory-based antibiotic resistance surveillance on MRSA in blood culture isolates have shown a downward trend over the last 4 years. In Gram-negative pathogens, a relatively stable resistance situation has been observed over this period for many of the pathogen-antibiotic combinations.

  2. Carbapenem-Resistant Non-Glucose-Fermenting Gram-Negative Bacilli: the Missing Piece to the Puzzle

    Science.gov (United States)

    Gniadek, Thomas J.; Carroll, Karen C.

    2016-01-01

    The non-glucose-fermenting Gram-negative bacilli Pseudomonas aeruginosa and Acinetobacter baumannii are increasingly acquiring carbapenem resistance. Given their intrinsic antibiotic resistance, this can cause extremely difficult-to-treat infections. Additionally, resistance gene transfer can occur between Gram-negative species, regardless of their ability to ferment glucose. Thus, the acquisition of carbapenemase genes by these organisms increases the risk of carbapenemase spread in general. Ultimately, infection control practitioners and clinical microbiologists need to work together to determine the risk carried by carbapenem-resistant non-glucose-fermenting Gram-negative bacilli (CR-NF) in their institution and what methods should be considered for surveillance and detection of CR-NF. PMID:26912753

  3. Association of late-onset neonatal sepsis with late neurodevelopment in the first two years of life of preterm infants with very low birth weight.

    Science.gov (United States)

    Hentges, Cláudia Regina; Silveira, Rita C; Procianoy, Renato Soibelmann; Carvalho, Clarissa Gutierrez; Filipouski, Gabriela Ribeiro; Fuentefria, Rubia Nascimento; Marquezotti, Fernanda; Terrazan, Ana Carolina

    2014-01-01

    To establish the influence of late-onset sepsis on neurodevelopment of preterm infants with very low birth weight (VLBW), according to the etiologic agent. This was a cohort of newborns with birth weight<1,500 g and gestational age less than 32 weeks, admitted to the institutional intensive care unit (ICU) with up to 48 hours of life, and followed-up at the outpatient follow-up clinic for preterm infants with VLBW until 2 years of corrected age. death within the first 72 hours of life, congenital malformations and genetic syndromes, children with congenital infection by the human immunodeficiency virus (HIV), congenital infection (STORCH), presence of early-onset sepsis and cases with more than one pathogen growth in blood cultures. Septic and non-septic infants were compared regarding neonatal outcomes and mortality. Neurodevelopment was assessed using the Bayley Scale (BSDI-II) at 18 to 24 months of corrected age. 411 preterm infants with VLBW were eligible; the mean gestational age was 29 ± 2.2 weeks and mean birth weight was 1,041 ± 281 grams. Late-onset sepsis occurred in 94 preterm infants with VLBW (22.8%). VLBW infants with Gram-positive infection showed motor deficit when compared to the non-septic group, 68.8% vs. 29.3%, respectively (OR 6; 1.6-21.8, p=0.006); the cognitive development was similar between the groups. The overall mortality rate from infection was 26.7%; considering the pathogens, the rates were 18.7% for coagulase-negative Staphylococcus, 21.8% for Gram-positive bacteria, and 50% for Gram-negative bacteria and fungi. Neonatal sepsis has a significant influence on late neurodevelopment at 2 years of corrected age in preterm infants with VLBW, and Gram-positive infections are associated with motor deficit. Copyright © 2013 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  4. Clinical guideline for diagnosis and management of melioidosis

    Directory of Open Access Journals (Sweden)

    Inglis Timothy J.J.

    2006-01-01

    Full Text Available Melioidosis is an emerging infection in Brazil and neighbouring South American countries. The wide range of clinical presentations include severe community-acquired pneumonia, septicaemia, central nervous system infection and less severe soft tissue infection. Diagnosis depends heavily on the clinical microbiology laboratory for culture. Burkholderia pseudomallei, the bacterial cause of melioidosis, is easily cultured from blood, sputum and other clinical samples. However, B. pseudomallei can be difficult to identify reliably, and can be confused with closely related bacteria, some of which may be dismissed as insignificant culture contaminants. Serological tests can help to support a diagnosis of melioidosis, but by themselves do not provide a definitive diagnosis. The use of a laboratory discovery pathway can help reduce the risk of missing atypical B. pseudomallei isolates. Recommended antibiotic treatment for severe infection is either intravenous Ceftazidime or Meropenem for several weeks, followed by up to 20 weeks oral treatment with a combination of trimethoprim-sulphamethoxazole and doxycycline. Consistent use of diagnostic microbiology to confirm the diagnosis, and rigorous treatment of severe infection with the correct antibiotics in two stages; acute and eradication, will contribute to a reduction in mortality from melioidosis.

  5. False-Negative Rate of Gram-Stain Microscopy for Diagnosis of Septic Arthritis: Suggestions for Improvement

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    Paul Stirling

    2014-01-01

    Full Text Available We quantify the false-negative diagnostic rate of septic arthritis using Gram-stain microscopy of synovial fluid and compare this to values reported in the peer-reviewed literature. We propose a method of improving the diagnostic value of Gram-stain microscopy using Lithium Heparin containers that prevent synovial fluid coagulation. Retrospective study of the Manchester Royal Infirmary microbiology database of patients undergoing synovial fluid Gram-stain and culture between December 2003 and March 2012 was undertaken. The initial cohort of 1896 synovial fluid analyses for suspected septic arthritis was reduced to 143 after exclusion criteria were applied. Analysis of our Gram-stain microscopy yielded 111 false-negative results from a cohort size of 143 positive synovial fluid cultures, giving a false-negative rate of 78%. We report a false-negative rate of Gram-stain microscopy for septic arthritis of 78%. Clinicians should therefore avoid the investigation until a statistically significant data set confirms its efficacy. The investigation's value could be improved by using Lithium Heparin containers to collect homogenous synovial fluid samples. Ongoing research aims to establish how much this could reduce the false-negative rate.

  6. Gram-negative and -positive bacteria differentiation in blood culture samples by headspace volatile compound analysis.

    Science.gov (United States)

    Dolch, Michael E; Janitza, Silke; Boulesteix, Anne-Laure; Graßmann-Lichtenauer, Carola; Praun, Siegfried; Denzer, Wolfgang; Schelling, Gustav; Schubert, Sören

    2016-12-01

    Identification of microorganisms in positive blood cultures still relies on standard techniques such as Gram staining followed by culturing with definite microorganism identification. Alternatively, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry or the analysis of headspace volatile compound (VC) composition produced by cultures can help to differentiate between microorganisms under experimental conditions. This study assessed the efficacy of volatile compound based microorganism differentiation into Gram-negatives and -positives in unselected positive blood culture samples from patients. Headspace gas samples of positive blood culture samples were transferred to sterilized, sealed, and evacuated 20 ml glass vials and stored at -30 °C until batch analysis. Headspace gas VC content analysis was carried out via an auto sampler connected to an ion-molecule reaction mass spectrometer (IMR-MS). Measurements covered a mass range from 16 to 135 u including CO2, H2, N2, and O2. Prediction rules for microorganism identification based on VC composition were derived using a training data set and evaluated using a validation data set within a random split validation procedure. One-hundred-fifty-two aerobic samples growing 27 Gram-negatives, 106 Gram-positives, and 19 fungi and 130 anaerobic samples growing 37 Gram-negatives, 91 Gram-positives, and two fungi were analysed. In anaerobic samples, ten discriminators were identified by the random forest method allowing for bacteria differentiation into Gram-negative and -positive (error rate: 16.7 % in validation data set). For aerobic samples the error rate was not better than random. In anaerobic blood culture samples of patients IMR-MS based headspace VC composition analysis facilitates bacteria differentiation into Gram-negative and -positive.

  7. Antimicrobial Activities of Leaf Extracts of Guava (Psidium guajava L.) on Two Gram-Negative and Gram-Positive Bacteria

    Science.gov (United States)

    Biswas, Bipul; Rogers, Kimberly; McLaughlin, Fredrick; Yadav, Anand

    2013-01-01

    Aim. To determine the antimicrobial potential of guava (Psidium guajava) leaf extracts against two gram-negative bacteria (Escherichia coli and Salmonella enteritidis) and two gram-positive bacteria (Staphylococcus aureus and Bacillus cereus) which are some of foodborne and spoilage bacteria. The guava leaves were extracted in four different solvents of increasing polarities (hexane, methanol, ethanol, and water). The efficacy of these extracts was tested against those bacteria through a well-diffusion method employing 50 μL leaf-extract solution per well. According to the findings of the antibacterial assay, the methanol and ethanol extracts of the guava leaves showed inhibitory activity against gram-positive bacteria, whereas the gram-negative bacteria were resistant to all the solvent extracts. The methanol extract had an antibacterial activity with mean zones of inhibition of 8.27 and 12.3 mm, and the ethanol extract had a mean zone of inhibition of 6.11 and 11.0 mm against B. cereus and S. aureus, respectively. On the basis of the present finding, guava leaf-extract might be a good candidate in the search for a natural antimicrobial agent. This study provides scientific understanding to further determine the antimicrobial values and investigate other pharmacological properties. PMID:24223039

  8. Antimicrobial Activities of Leaf Extracts of Guava (Psidium guajava L. on Two Gram-Negative and Gram-Positive Bacteria

    Directory of Open Access Journals (Sweden)

    Bipul Biswas

    2013-01-01

    Full Text Available Aim. To determine the antimicrobial potential of guava (Psidium guajava leaf extracts against two gram-negative bacteria (Escherichia coli and Salmonella enteritidis and two gram-positive bacteria (Staphylococcus aureus and Bacillus cereus which are some of foodborne and spoilage bacteria. The guava leaves were extracted in four different solvents of increasing polarities (hexane, methanol, ethanol, and water. The efficacy of these extracts was tested against those bacteria through a well-diffusion method employing 50 μL leaf-extract solution per well. According to the findings of the antibacterial assay, the methanol and ethanol extracts of the guava leaves showed inhibitory activity against gram-positive bacteria, whereas the gram-negative bacteria were resistant to all the solvent extracts. The methanol extract had an antibacterial activity with mean zones of inhibition of 8.27 and 12.3 mm, and the ethanol extract had a mean zone of inhibition of 6.11 and 11.0 mm against B. cereus and S. aureus, respectively. On the basis of the present finding, guava leaf-extract might be a good candidate in the search for a natural antimicrobial agent. This study provides scientific understanding to further determine the antimicrobial values and investigate other pharmacological properties.

  9. First case report of sepsis caused by Rhizobium pusense in Japan.

    Science.gov (United States)

    Kuchibiro, Tomokazu; Hirayama, Katsuhisa; Houdai, Katsuyuki; Nakamura, Tatsuya; Ohnuma, Kenichirou; Tomida, Junko; Kawamura, Yoshiaki

    2018-01-01

    Species of the genus Rhizobium are opportunistic, usually saprophytic, glucose-non-fermenting, Gram-negative bacilli found in agricultural soil. Rhizobium pusense infections are the least common Rhizobium infections and have low incidence. Herein, we report the first case of sepsis with R. pusense in Japan in a 67-year-old Japanese woman with a history of hyperlipidaemia, hypertension, diabetes, hypothyroidism and osteoporosis. She had undergone cerebrovascular treatment because she was diagnosed with a subarachnoid haemorrhage. The results of postoperative blood culture showed oxidase-positive, urease-positive, non-lactose-fermenting Gram-stain-negative rods. Using the Vitek2 system, the isolate was distinctly identified as Rhizobium radiobacter . However, 16S rRNA gene sequencing showed 99.93 % similarity with the type strain of R. pusense and 99.06 % similarity with the type strain of R. radiobacter . Additional gene sequencing analysis using recA (97.2 %) and atpD (96.2 %) also showed that the isolated strain is most closely related to R. pusense . The patient was cured by treatment using intravenous meropenem (3 g/d) for 4 weeks and was discharged safely. The definite source of sepsis was unknown. However, the possibility of having been infected through the catheter during the cerebrovascular operation was speculated.

  10. Characterisation and antimicrobial resistance of sepsis pathogens in neonates born in tertiary care centres in Delhi, India: a cohort study.

    Science.gov (United States)

    2016-10-01

    Sepsis is one of the most common causes of neonatal deaths globally. Most sepsis-related deaths occur in low-income and middle-income countries, where the epidemiology of neonatal sepsis remains poorly understood. Most of these countries lack proper surveillance networks, hampering accurate assessment of the burden of sepsis, implementation of preventive measures, and investment in research. We report results of neonates born in hospital from a multicentre collaboration on neonatal sepsis. In this cohort study, dedicated research teams prospectively followed up neonates born in one of three tertiary care centres in Delhi, India (Vardhaman Mahavir Medical College, Maulana Azad Medical College, and All India Institute of Medical Sciences [coordinating centre]) and subsequently admitted to the intensive care unit. Neonates were followed up daily until discharge or death. On clinical suspicion, neonates underwent sepsis work-up including blood cultures. The isolated organisms were identified and tested for antimicrobial susceptibility. We defined Gram-negative isolates resistant to any three of five antibiotic classes (extended-spectrum cephalosporins, carbapenems, aminoglycosides, fluoroquinolones, and piperacillin-tazobactam) as multidrug resistant. 13 530 neonates of 88 636 livebirths were enrolled between July 18, 2011, and Feb 28, 2014. The incidence of total sepsis was 14·3% (95% CI 13·8-14·9) and of culture-positive sepsis was 6·2% (5·8-6·6). Nearly two-thirds of total episodes occurred at or before 72 h of life (defined as early onset; 1351 [83%] of 1980). Two-thirds (645 [64%]) of 1005 isolates were Gram-negative including, Acinetobacter spp (22%), Klebsiella spp (17%), and Escherichia coli (14%). The pathogen mix in early-onset sepsis did not differ from that of late-onset sepsis (ie, after 72 h). High rates of multidrug resistance were observed in Acinetobacter spp (181/222, 82%), Klebsiella spp (91/169, 54%), and Escherichia coli (52/137, 38

  11. Dual beta-lactam therapy for serious Gram-negative infections: is it time to revisit?

    Science.gov (United States)

    Rahme, Christine; Butterfield, Jill M; Nicasio, Anthony M; Lodise, Thomas P

    2014-12-01

    We are rapidly approaching a crisis in antibiotic resistance, particularly among Gram-negative pathogens. This, coupled with the slow development of novel antimicrobial agents, underscores the exigency of redeploying existing antimicrobial agents in innovative ways. One therapeutic approach that was heavily studied in the 1980s but abandoned over time is dual beta-lactam therapy. This article reviews the evidence for combination beta-lactam therapy. Overall, in vitro, animal and clinical data are positive and suggest that beta-lactam combinations produce a synergistic effect against Gram-negative pathogens that rivals that of beta-lactam-aminoglycoside or beta-lactam-fluoroquinolone combination therapy. Although the precise mechanism of improved activity is not completely understood, it is likely attributable to an enhanced affinity to the diverse penicillin-binding proteins found among Gram negatives. The collective data indicate that dual beta-lactam therapy should be revisited for serious Gram-negative infections, especially in light of the near availability of potent beta-lactamase inhibitors, which neutralize the effect of problematic beta-lactamases. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Bovine mastitis caused by gram negative bacteria in Mosul

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    S. Y. A. Al-Dabbagh

    2012-01-01

    Full Text Available A total of 90 milk samples were collected from cows with clinical and subclinical mastitis from different areas in Mosul city, in a period from October 2009 to June 2010, for the detection of gram negative bacteriological causative agents. The bacteria were identified using morphological, cultural and biochemical characteristics. thirty tow (35.3% gram negative bacterial isolates were obtained from the total count which included 14 isolates (15.5% for Escherichia coli, 7 isolates (7.7% for Klebsiella spp, 4 isolates (4.4% for Pseudomonas aeruginosa, 3 isolates (3.3% for Enterobacter aerogenes ,2 isolates for Serratia marcescens and one isolates (1.1% for each of Aeromonas hydrophila and Pasteurella multocida. Results of antibiotic sensitivity test indicated that most of these isolates were sensitive to Ciprofloxacin following by Gentamycin and Cotrimoxazole, while most of these organisms were resistant to Ampicillin, the isolates showed different percentages of sensitivity to Doxycycline, Tetracycline, Neomycin and Chloramphenicol.

  13. Antibiotic-Resistant Gram Negative Bacilli in Meals Delivered at a General Hospital, Italy

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    Maria Rosa Anna Plano

    2009-01-01

    Full Text Available This study aimed at detecting the presence of antibiotic-resistant Gram-negatives in samples of meals delivered at the University General Hospital of Palermo, Italy. Antibiotic resistant Gram negatives were isolated in July—September 2007 ffrom cold dishes and food contact surfaces and utensils. Bacterial strains were submitted to susceptibility test and subtyped by random amplification of polymorphic DNA (RAPD. Forty-six of 55 (83.6% food samples and 14 of 17 (82.3% environmental swabs were culture positive for Gram negative bacilli resistant to at least one group of antibacterial drugs. A total of 134 antibiotic resistant strains, 51 fermenters and 83 non-fermenters, were recovered. Fermenters and non-fermenters showed frequencies as high as 97.8% of resistance to two or more groups of antibiotics and non fermenters were 28.9% resistant to more than three groups. Molecular typing detected 34 different profiles among the fermenters and 68 among the non-fermenters. Antibiotic resistance was very common among both fermenters and non-fermenters. However, the wide heterogeneity of RAPD patterns seems to support a prominent role of cross-contamination rather than a clonal expansion of a few resistant isolates. A contribution of commensal Gram negatives colonizing foods to a common bacterial resistance pool should not been overlooked.

  14. Antibiotic-resistant gram negative bacilli in meals delivered at a general hospital, Italy.

    Science.gov (United States)

    Plano, Maria Rosa Anna; Di Noto, Anna Maria; Firenze, Alberto; Sciortino, Sonia; Mammina, Caterina

    2009-01-01

    This study aimed at detecting the presence of antibiotic-resistant Gram-negatives in samples of meals delivered at the University General Hospital of Palermo, Italy. Antibiotic resistant Gram negatives were isolated in July-September 2007 ffrom cold dishes and food contact surfaces and utensils. Bacterial strains were submitted to susceptibility test and subtyped by random amplification of polymorphic DNA (RAPD). Forty-six of 55 (83.6%) food samples and 14 of 17 (82.3%) environmental swabs were culture positive for Gram negative bacilli resistant to at least one group of antibacterial drugs. A total of 134 antibiotic resistant strains, 51 fermenters and 83 non-fermenters, were recovered. Fermenters and non-fermenters showed frequencies as high as 97.8% of resistance to two or more groups of antibiotics and non fermenters were 28.9% resistant to more than three groups. Molecular typing detected 34 different profiles among the fermenters and 68 among the non-fermenters. Antibiotic resistance was very common among both fermenters and non-fermenters. However, the wide heterogeneity of RAPD patterns seems to support a prominent role of cross-contamination rather than a clonal expansion of a few resistant isolates. A contribution of commensal Gram negatives colonizing foods to a common bacterial resistance pool should not been overlooked.

  15. Outcomes of single organism peritonitis in peritoneal dialysis: gram negatives versus gram positives in the Network 9 Peritonitis Study.

    Science.gov (United States)

    Bunke, C M; Brier, M E; Golper, T A

    1997-08-01

    The use of the "peritonitis rate" in the management of patients undergoing peritoneal dialysis is assuming importance in comparing the prowess of facilities, care givers and new innovations. For this to be a meaningful outcome measure, the type of infection (causative pathogen) must have less clinical significance than the number of infections during a time interval. The natural history of Staphylococcus aureus, pseudomonas, and fungal peritonitis would not support that the outcome of an episode of peritonitis is independent of the causative pathogen. Could this concern be extended to other more frequently occurring pathogens? To address this, the Network 9 Peritonitis Study identified 530 episodes of single organism peritonitis caused by a gram positive organism and 136 episodes caused by a single non-pseudomonal gram negative (NPGN) pathogen. Coincidental soft tissue infections (exit site or tunnel) occurred equally in both groups. Outcomes of peritonitis were analyzed by organism classification and by presence or absence of a soft tissue infection. NPGN peritonitis was associated with significantly more frequent catheter loss, hospitalization, and technique failure and was less likely to resolve regardless of the presence or absence of a soft tissue infection. Hospitalization and death tended to occur more frequently with enterococcal peritonitis than with other gram positive peritonitis. The outcomes in the NPGN peritonitis group were significantly worse (resolution, catheter loss, hospitalization, technique failure) compared to coagulase negative staphylococcal or S. aureus peritonitis, regardless of the presence or absence of a coincidental soft tissue infection. Furthermore, for the first time, the poor outcomes of gram negative peritonitis are shown to be independent of pseudomonas or polymicrobial involvement or soft tissue infections. The gram negative organism appears to be the important factor. In addition, the outcome of peritonitis caused by S. aureus

  16. Association between sepsis and Rocky Mountain spotted fever.

    Science.gov (United States)

    Bacci, Marcelo Rodrigues; Namura, José Jorge

    2012-12-06

    Rocky Mountain spotted fever (RMSF) is a disease caused by the Gram-negative coccobacillus Rickettsia ricketsii which has been on the rise since the last decade in the USA. The symptoms are common to the many viral diseases, and the classic triad of fever, rash and headache is not always present when RMSF is diagnosed. It may progress to severe cases such as renal failure, disseminated intravascular coagulation and septicaemia. This report aims to present a fulminant case of RMSF associated with sepsis. It describes a female patient's case that quickly progressed to sepsis and death. The patient showed non-specific symptoms for 5 days before being admitted to a hospital. The fact that she lived in an area highly infested with Amblyomma aureolatum ticks was unknown to the medical staff until the moment she died.

  17. Detection and Antibiotic Susceptibility Pattern of Biofilm Producing Gram Positive and Gram Negative Bacteria Isolated From a Tertiary Care Hospital of Pakistan

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    Iqbal, M.

    2011-01-01

    Full Text Available Microorganisms adhere to non-living material or living tissue, and form biofilms made up of extracellular polymers/slime. Biofilm-associated microorganisms behave differently from free-floating bacteria with respect to growth rates and ability to resist antimicrobial treatments and therefore pose a public health problem. The objective of this study is to detect the prevalence of biofilm producers among Gram positive and Gram negative bacteria isolated from clinical specimens, and to study their antimicrobial susceptibility pattern. The study was carried out from October 2009 to March 2010, at the Department of Microbiology, Army Medical College/ National University of Sciences and Technology (NUST, Rawalpindi, Pakistan. Clinical specimens were received from various wards of a tertiary care hospital. These were dealt by standard microbiological procedures. Gram positive and Gram negative bacteria isolated were subjected to biofilm detection by congo red agar method (CRA. Antimicrobial susceptibility testing of those isolates, which showed positive results (slime production, was done according to the Kirby-Bauer disc diffusion technique. A total of 150 isolates were tested for the production of biofilm/slime. Among them, 81 isolates showed positive results. From these 81, 51 were Gram positive and 30 were Gram negative. All the 81(54% slime producers showed reduced susceptibility to majority of antibiotics. Bacterial biofilms are an important virulence factor associated with chronic nosocomial infection. Detection of biofilm forming organisms can help in appropriate antibiotic choice.

  18. Multi-location gram-positive and gram-negative bacterial protein subcellular localization using gene ontology and multi-label classifier ensemble.

    Science.gov (United States)

    Wang, Xiao; Zhang, Jun; Li, Guo-Zheng

    2015-01-01

    It has become a very important and full of challenge task to predict bacterial protein subcellular locations using computational methods. Although there exist a lot of prediction methods for bacterial proteins, the majority of these methods can only deal with single-location proteins. But unfortunately many multi-location proteins are located in the bacterial cells. Moreover, multi-location proteins have special biological functions capable of helping the development of new drugs. So it is necessary to develop new computational methods for accurately predicting subcellular locations of multi-location bacterial proteins. In this article, two efficient multi-label predictors, Gpos-ECC-mPLoc and Gneg-ECC-mPLoc, are developed to predict the subcellular locations of multi-label gram-positive and gram-negative bacterial proteins respectively. The two multi-label predictors construct the GO vectors by using the GO terms of homologous proteins of query proteins and then adopt a powerful multi-label ensemble classifier to make the final multi-label prediction. The two multi-label predictors have the following advantages: (1) they improve the prediction performance of multi-label proteins by taking the correlations among different labels into account; (2) they ensemble multiple CC classifiers and further generate better prediction results by ensemble learning; and (3) they construct the GO vectors by using the frequency of occurrences of GO terms in the typical homologous set instead of using 0/1 values. Experimental results show that Gpos-ECC-mPLoc and Gneg-ECC-mPLoc can efficiently predict the subcellular locations of multi-label gram-positive and gram-negative bacterial proteins respectively. Gpos-ECC-mPLoc and Gneg-ECC-mPLoc can efficiently improve prediction accuracy of subcellular localization of multi-location gram-positive and gram-negative bacterial proteins respectively. The online web servers for Gpos-ECC-mPLoc and Gneg-ECC-mPLoc predictors are freely accessible

  19. [Characteristic of clinical strains of gram-negative obligate anaerobes].

    Science.gov (United States)

    Kadzielska, Joanna; Kierzkowska, Marta; Sawicka-Grzelak, Anna; Rokosz, Alicja; Łuczak, Mirosław

    2007-01-01

    The aim of the study was to assess prevalence and antibiotic susceptibility profiles ofGram-negative strictly anaerobic bacteria isolated from clinical specimens taken from hospitalized patients in 2005-2006. Biochemical identification and antibiotic susceptibility were done in an automated system ATB Expression (bioMerieux sa). From 12262 specimens examined 867 strains of obligate anaerobes were isolated. Gram-negative strictly anaerobic bacteria were cultured in number of 138 strains (15,9%). All cultures were performed on Columbia agar and Schaedler agar media (bioMerieux sa) supplemented with 5% sheep blood and incubated at 37 degrees C for 48-120 h in 85% N2, 10% H2, 5% CO2. Most frequently isolated was Bacteroides spp. (41,3%). For this group beta-lactamase activity was evaluated by using nitrocefin disc test (Cefinase BBL, Becton Dickinson and Co., Cockeysville, MD, USA). Production of ESBLs was detected with the use of two disc diffusion methods: the double-disc synergy test (DDST) according to Jarlier et al. and the diagnostic disc (DD) test according to Appleton. ESBLs were produced by 5,3% strains of Bacteroides spp. For all Bacteroides spp. strains MIC values were determined by gradient diffusion method Etest (AB BIODISK, Sweden). ESBLs and MIC were performed on Wilkins-Chalgren solid medium supplemented with 5% sheep blood (Difco Lab., USA) and all plates were incubated at 35 degrees C for 48 hours in 85% N2, 10% H2, 5% CO2. Most Gram-negative obligate anaerobes isolated from clinical specimens are still susceptible to imipenem (100%), metronidazole (99,3%) and beta-lactam antibiotics with beta-lactamase inhibitors: piperacillin/tazobactam (99,3%), ticarcillin/clavulanate (99.3%), amoxicillin/clavulanate (97.8%).

  20. Guillain Barre syndrome as a manifestation of neurological melioidosis

    Directory of Open Access Journals (Sweden)

    Rajesh Krovvidi

    2013-01-01

    Full Text Available Neurological melioidosis is a very rare and very few cases have been reported from India. Presentation is an extremely varied and as this disease is associated with high mortality, high index of suspicion is needed to diagnose and treat. In this context, we report a patient presenting as Guillain Barre syndrome evaluated as melioidosis.

  1. Melioidosis in the Lao People’s Democratic Republic

    Directory of Open Access Journals (Sweden)

    David A.B. Dance

    2018-02-01

    Full Text Available Melioidosis is clearly highly endemic in Laos, although the disease has only been diagnosed regularly in humans (1359 cases since 1999, and only a single animal case has been microbiologically confirmed. Burkholderia pseudomallei is extensively and abundantly present in soil and surface water in central and southern Laos, but the true distribution of the disease across the country remains to be determined. Surveillance is almost non-existent and diagnostic microbiology services are not yet well established, whilst awareness of melioidosis is low amongst policy-makers, healthcare providers, and the public. It is hoped that this situation will improve over the next decade as the country rapidly develops, especially as this is likely to be accompanied by a further increase in the prevalence of diabetes, meaning that more people in this predominantly agricultural population will be at risk of contracting melioidosis.

  2. Rapid, highly sensitive detection of Gram-negative bacteria with lipopolysaccharide based disposable aptasensor.

    Science.gov (United States)

    Zhang, Jian; Oueslati, Rania; Cheng, Cheng; Zhao, Ling; Chen, Jiangang; Almeida, Raul; Wu, Jayne

    2018-07-30

    Gram-negative bacteria are one of the most common microorganisms in the environment. Their differential detection and recognition from Gram-positive bacteria has been attracting much attention over the years. Using Escherichia coli (E. coli) as a model, we demonstrated on-site detection of Gram-negative bacteria by an AC electrokinetics-based capacitive sensing method using commercial microelectrodes functionalized with an aptamer specific to lipopolysaccharides. Dielectrophoresis effect was utilized to enrich viable bacteria to the microelectrodes rapidly, achieving a detection limit of 10 2 cells/mL within a 30 s' response time. The sensor showed a negligible response to Staphylococcus aureus (S. aureus), a Gram-positive species. The developed sensor showed significant advantages in sensitivity, selectivity, cost, operation simplicity, and response time. Therefore, this sensing method has shown great application potential for environmental monitoring, food safety, and real-time diagnosis. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. A pathway closely related to the (D)-tagatose pathway of gram-negative enterobacteria identified in the gram-positive bacterium Bacillus licheniformis.

    Science.gov (United States)

    Van der Heiden, Edwige; Delmarcelle, Michaël; Lebrun, Sarah; Freichels, Régine; Brans, Alain; Vastenavond, Christian M; Galleni, Moreno; Joris, Bernard

    2013-06-01

    We report the first identification of a gene cluster involved in d-tagatose catabolism in Bacillus licheniformis. The pathway is closely related to the d-tagatose pathway of the Gram-negative bacterium Klebsiella oxytoca, in contrast to the d-tagatose 6-phosphate pathway described in the Gram-positive bacterium Staphylococcus aureus.

  4. A Pathway Closely Related to the d-Tagatose Pathway of Gram-Negative Enterobacteria Identified in the Gram-Positive Bacterium Bacillus licheniformis

    OpenAIRE

    Van der Heiden, Edwige; Delmarcelle, Michaël; Lebrun, Sarah; Freichels, Régine; Brans, Alain; Vastenavond, Christian M.; Galleni, Moreno; Joris, Bernard

    2013-01-01

    We report the first identification of a gene cluster involved in d-tagatose catabolism in Bacillus licheniformis. The pathway is closely related to the d-tagatose pathway of the Gram-negative bacterium Klebsiella oxytoca, in contrast to the d-tagatose 6-phosphate pathway described in the Gram-positive bacterium Staphylococcus aureus.

  5. Associations Between Enteral Colonization With Gram-Negative Bacteria and Intensive Care Unit-Acquired Infections and Colonization of the Respiratory Tract.

    Science.gov (United States)

    Frencken, Jos F; Wittekamp, Bastiaan H J; Plantinga, Nienke L; Spitoni, Cristian; van de Groep, Kirsten; Cremer, Olaf L; Bonten, Marc J M

    2018-02-01

    Enteral and respiratory tract colonization with gram-negative bacteria may lead to subsequent infections in critically ill patients. We aimed to clarify the interdependence between gut and respiratory tract colonization and their associations with intensive care unit (ICU)-acquired infections in patients receiving selective digestive tract decontamination (SDD). Colonization status of the rectum and respiratory tract was determined using twice-weekly microbiological surveillance in mechanically ventilated subjects receiving SDD between May 2011 and June 2015 in a tertiary medical-surgical ICU in the Netherlands. Acquisition of infections was monitored daily by dedicated observers. Marginal structural models were used to determine the associations between gram-negative rectal colonization and respiratory tract colonization, ICU-acquired gram-negative infection, and ICU-acquired gram-negative bacteremia. Among 2066 ICU admissions, 1157 (56.0%) ever had documented gram-negative carriage in the rectum during ICU stay. Cumulative incidences of ICU-acquired gram-negative infection and bacteremia were 6.0% (n = 124) and 2.1% (n = 44), respectively. Rectal colonization was an independent risk factor for both respiratory tract colonization (cause-specific hazard ratio [CSHR], 2.93 [95% confidence interval {CI}, 2.02-4.23]) and new gram-negative infection in the ICU (CSHR, 3.04 [95% CI, 1.99-4.65]). Both rectal and respiratory tract colonization were associated with bacteremia (CSHR, 7.37 [95% CI, 3.25-16.68] and 2.56 [95% CI, 1.09-6.03], respectively). Similar associations were observed when Enterobacteriaceae and glucose nonfermenting gram-negative bacteria were analyzed separately. Gram-negative rectal colonization tends to be stronger associated with subsequent ICU-acquired gram-negative infections than gram-negative respiratory tract colonization. Gram-negative rectal colonization seems hardly associated with subsequent ICU-acquired gram-negative respiratory tract

  6. A Pathway Closely Related to the d-Tagatose Pathway of Gram-Negative Enterobacteria Identified in the Gram-Positive Bacterium Bacillus licheniformis

    Science.gov (United States)

    Van der Heiden, Edwige; Lebrun, Sarah; Freichels, Régine; Brans, Alain; Vastenavond, Christian M.; Galleni, Moreno; Joris, Bernard

    2013-01-01

    We report the first identification of a gene cluster involved in d-tagatose catabolism in Bacillus licheniformis. The pathway is closely related to the d-tagatose pathway of the Gram-negative bacterium Klebsiella oxytoca, in contrast to the d-tagatose 6-phosphate pathway described in the Gram-positive bacterium Staphylococcus aureus. PMID:23524682

  7. Non-oral gram-negative facultative rods in chronic periodontitis microbiota

    NARCIS (Netherlands)

    van Winkelhoff, Arie J; Rurenga, Patrick; Wekema-Mulder, Gepke J; Singadji, Zadnach; Rams, Thomas E

    OBJECTIVE: The subgingival prevalence of gram-negative facultative rods not usually inhabiting or indigenous to the oral cavity (non-oral GNFR), as well as selected periodontal bacterial pathogens, were evaluated by culture in untreated and treated chronic periodontitis patients. METHODS:

  8. A Melioidosis Case in Arizona

    Centers for Disease Control (CDC) Podcasts

    2011-10-03

    David Blaney, Medical Officer, Bacterial Special Pathogens Branch, discusses an unusual melioidosis case in Arizona.  Created: 10/3/2011 by National Center for Emerging Zoonotic and Infectious Diseases (NCEZID).   Date Released: 10/5/2011.

  9. Curative Treatment of Severe Gram-Negative Bacterial Infections by a New Class of Antibiotics Targeting LpxC.

    Science.gov (United States)

    Lemaître, Nadine; Liang, Xiaofei; Najeeb, Javaria; Lee, Chul-Jin; Titecat, Marie; Leteurtre, Emmanuelle; Simonet, Michel; Toone, Eric J; Zhou, Pei; Sebbane, Florent

    2017-07-25

    The infectious diseases caused by multidrug-resistant bacteria pose serious threats to humankind. It has been suggested that an antibiotic targeting LpxC of the lipid A biosynthetic pathway in Gram-negative bacteria is a promising strategy for curing Gram-negative bacterial infections. However, experimental proof of this concept is lacking. Here, we describe our discovery and characterization of a biphenylacetylene-based inhibitor of LpxC, an essential enzyme in the biosynthesis of the lipid A component of the outer membrane of Gram-negative bacteria. The compound LPC-069 has no known adverse effects in mice and is effective in vitro against a broad panel of Gram-negative clinical isolates, including several multiresistant and extremely drug-resistant strains involved in nosocomial infections. Furthermore, LPC-069 is curative in a murine model of one of the most severe human diseases, bubonic plague, which is caused by the Gram-negative bacterium Yersinia pestis Our results demonstrate the safety and efficacy of LpxC inhibitors as a new class of antibiotic against fatal infections caused by extremely virulent pathogens. The present findings also highlight the potential of LpxC inhibitors for clinical development as therapeutics for infections caused by multidrug-resistant bacteria. IMPORTANCE The rapid spread of antimicrobial resistance among Gram-negative bacilli highlights the urgent need for new antibiotics. Here, we describe a new class of antibiotics lacking cross-resistance with conventional antibiotics. The compounds inhibit LpxC, a key enzyme in the lipid A biosynthetic pathway in Gram-negative bacteria, and are active in vitro against a broad panel of clinical isolates of Gram-negative bacilli involved in nosocomial and community infections. The present study also constitutes the first demonstration of the curative treatment of bubonic plague by a novel, broad-spectrum antibiotic targeting LpxC. Hence, the data highlight the therapeutic potential of Lpx

  10. Curative Treatment of Severe Gram-Negative Bacterial Infections by a New Class of Antibiotics Targeting LpxC

    Energy Technology Data Exchange (ETDEWEB)

    Lemaître, Nadine; Liang, Xiaofei; Najeeb, Javaria; Lee, Chul-Jin; Titecat, Marie; Leteurtre, Emmanuelle; Simonet, Michel; Toone, Eric J.; Zhou, Pei; Sebbane, Florent; Nacy, Carol A.

    2017-07-25

    ABSTRACT

    The infectious diseases caused by multidrug-resistant bacteria pose serious threats to humankind. It has been suggested that an antibiotic targeting LpxC of the lipid A biosynthetic pathway in Gram-negative bacteria is a promising strategy for curing Gram-negative bacterial infections. However, experimental proof of this concept is lacking. Here, we describe our discovery and characterization of a biphenylacetylene-based inhibitor of LpxC, an essential enzyme in the biosynthesis of the lipid A component of the outer membrane of Gram-negative bacteria. The compound LPC-069 has no known adverse effects in mice and is effectivein vitroagainst a broad panel of Gram-negative clinical isolates, including several multiresistant and extremely drug-resistant strains involved in nosocomial infections. Furthermore, LPC-069 is curative in a murine model of one of the most severe human diseases, bubonic plague, which is caused by the Gram-negative bacteriumYersinia pestis. Our results demonstrate the safety and efficacy of LpxC inhibitors as a new class of antibiotic against fatal infections caused by extremely virulent pathogens. The present findings also highlight the potential of LpxC inhibitors for clinical development as therapeutics for infections caused by multidrug-resistant bacteria.

    IMPORTANCEThe rapid spread of antimicrobial resistance among Gram-negative bacilli highlights the urgent need for new antibiotics. Here, we describe a new class of antibiotics lacking cross-resistance with conventional antibiotics. The compounds inhibit LpxC, a key enzyme in the lipid A biosynthetic pathway in Gram-negative bacteria, and are activein vitroagainst a broad panel of clinical isolates of Gram-negative bacilli involved in nosocomial and community infections. The present study also constitutes the first demonstration of the curative treatment of bubonic plague by a novel, broad

  11. Metabolomic Profiling of Plasma from Melioidosis Patients Using UHPLC-QTOF MS Reveals Novel Biomarkers for Diagnosis

    Directory of Open Access Journals (Sweden)

    Susanna K. P. Lau

    2016-02-01

    Full Text Available To identify potential biomarkers for improving diagnosis of melioidosis, we compared plasma metabolome profiles of melioidosis patients compared to patients with other bacteremia and controls without active infection, using ultra-high-performance liquid chromatography-electrospray ionization-quadruple time-of-flight mass spectrometry. Principal component analysis (PCA showed that the metabolomic profiles of melioidosis patients are distinguishable from bacteremia patients and controls. Using multivariate and univariate analysis, 12 significant metabolites from four lipid classes, acylcarnitine (n = 6, lysophosphatidylethanolamine (LysoPE (n = 3, sphingomyelins (SM (n = 2 and phosphatidylcholine (PC (n = 1, with significantly higher levels in melioidosis patients than bacteremia patients and controls, were identified. Ten of the 12 metabolites showed area-under-receiver operating characteristic curve (AUC >0.80 when compared both between melioidosis and bacteremia patients, and between melioidosis patients and controls. SM(d18:2/16:0 possessed the largest AUC when compared, both between melioidosis and bacteremia patients (AUC 0.998, sensitivity 100% and specificity 91.7%, and between melioidosis patients and controls (AUC 1.000, sensitivity 96.7% and specificity 100%. Our results indicate that metabolome profiling might serve as a promising approach for diagnosis of melioidosis using patient plasma, with SM(d18:2/16:0 representing a potential biomarker. Since the 12 metabolites were related to various pathways for energy and lipid metabolism, further studies may reveal their possible role in the pathogenesis and host response in melioidosis.

  12. Metabolomic Profiling of Plasma from Melioidosis Patients Using UHPLC-QTOF MS Reveals Novel Biomarkers for Diagnosis.

    Science.gov (United States)

    Lau, Susanna K P; Lee, Kim-Chung; Lo, George C S; Ding, Vanessa S Y; Chow, Wang-Ngai; Ke, Tony Y H; Curreem, Shirly O T; To, Kelvin K W; Ho, Deborah T Y; Sridhar, Siddharth; Wong, Sally C Y; Chan, Jasper F W; Hung, Ivan F N; Sze, Kong-Hung; Lam, Ching-Wan; Yuen, Kwok-Yung; Woo, Patrick C Y

    2016-02-27

    To identify potential biomarkers for improving diagnosis of melioidosis, we compared plasma metabolome profiles of melioidosis patients compared to patients with other bacteremia and controls without active infection, using ultra-high-performance liquid chromatography-electrospray ionization-quadruple time-of-flight mass spectrometry. Principal component analysis (PCA) showed that the metabolomic profiles of melioidosis patients are distinguishable from bacteremia patients and controls. Using multivariate and univariate analysis, 12 significant metabolites from four lipid classes, acylcarnitine (n = 6), lysophosphatidylethanolamine (LysoPE) (n = 3), sphingomyelins (SM) (n = 2) and phosphatidylcholine (PC) (n = 1), with significantly higher levels in melioidosis patients than bacteremia patients and controls, were identified. Ten of the 12 metabolites showed area-under-receiver operating characteristic curve (AUC) >0.80 when compared both between melioidosis and bacteremia patients, and between melioidosis patients and controls. SM(d18:2/16:0) possessed the largest AUC when compared, both between melioidosis and bacteremia patients (AUC 0.998, sensitivity 100% and specificity 91.7%), and between melioidosis patients and controls (AUC 1.000, sensitivity 96.7% and specificity 100%). Our results indicate that metabolome profiling might serve as a promising approach for diagnosis of melioidosis using patient plasma, with SM(d18:2/16:0) representing a potential biomarker. Since the 12 metabolites were related to various pathways for energy and lipid metabolism, further studies may reveal their possible role in the pathogenesis and host response in melioidosis.

  13. An 11-Year Analysis of Emergency Presentations of Melioidosis in Northeastern Malaysia.

    Science.gov (United States)

    Yazid, Mohd Boniami; Fauzi, Mohd Hashairi; Hasan, Habsah; Md Noh, Abu Yazid; Deris, Zakuan Zainy

    2017-06-01

    A neglected tropical disease, melioidosis is known to have variability in clinical presentations. Here, we described clinical features that should alert the physicians on the possibility of melioidosis. In this review of 86 cases from 2001 to 2011, the common presentations of melioidosis in the Emergency Department (ED), Hospital Universiti Sains Malaysia were; male gender (79.1 %), in working age group (47.8 ± 15.2 year-old), worked in contact with soil (73.3 %), presented with fever (91.9 %), in rainy season (55.8 %), have underlying diabetes mellitus (79.1 %), have leukocytosis (67.4 %) and high blood glucose (62.8 %) during presentation. In 34.9 % of cases, the antimicrobials were initiated at the ED and only 10.5 % include antimelioid drugs. Thirty-one patients (36.0 %) died due to melioidosis and 51.6 % of this were within 48 h of admission. Despite high mortality rate, the clinical awareness on the possibility of melioidosis among emergency physicians is still low and need to be strengthened.

  14. Development and transmission of antimicrobial resistance among Gram-negative bacteria in animals and their public health impact.

    Science.gov (United States)

    Mukerji, Shewli; O'Dea, Mark; Barton, Mary; Kirkwood, Roy; Lee, Terence; Abraham, Sam

    2017-02-28

    Gram-negative bacteria are known to cause severe infections in both humans and animals. Antimicrobial resistance (AMR) in Gram-negative bacteria is a major challenge in the treatment of clinical infections globally due to the propensity of these organisms to rapidly develop resistance against antimicrobials in use. In addition, Gram-negative bacteria possess highly efficient mechanisms through which the AMR can be disseminated between pathogenic and commensal bacteria of the same or different species. These unique traits of Gram-negative bacteria have resulted in evolution of Gram-negative bacterial strains demonstrating resistance to multiple classes of antimicrobials. The evergrowing resistance issue has not only resulted in limitation of treatment options but also led to increased treatment costs and mortality rates in humans and animals. With few or no new antimicrobials in production to combat severe life-threatening infections, AMR has been described as the one of the most severe, long-term threats to human health. Aside from overuse and misuse of antimicrobials in humans, another factor that has exacerbated the emergence of AMR in Gram-negative bacteria is the veterinary use of antimicrobials that belong to the same classes considered to be critically important for treating serious life-threatening infections in humans. Despite the fact that development of AMR dates back to before the introduction of antimicrobials, the recent surge in the resistance towards all available critically important antimicrobials has emerged as a major public health issue. This review thus focuses on discussing the development, transmission and public health impact of AMR in Gram-negative bacteria in animals. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  15. Surface-Exposed Lipoproteins: An Emerging Secretion Phenomenon in Gram-Negative Bacteria.

    Science.gov (United States)

    Wilson, Marlena M; Bernstein, Harris D

    2016-03-01

    Bacterial lipoproteins are hydrophilic proteins that are anchored to a cell membrane by N-terminally linked fatty acids. It is widely believed that nearly all lipoproteins produced by Gram-negative bacteria are either retained in the inner membrane (IM) or transferred to the inner leaflet of the outer membrane (OM). Lipoproteins that are exposed on the cell surface have also been reported but are generally considered to be rare. Results from a variety of recent studies, however, now suggest that the prevalence of surface-exposed lipoproteins has been underestimated. In this review we describe the evidence that the surface exposure of lipoproteins in Gram-negative bacteria is a widespread phenomenon and discuss possible mechanisms by which these proteins might be transported across the OM. Published by Elsevier Ltd.

  16. In vitro activity of XF-73, a novel antibacterial agent, against antibiotic-sensitive and -resistant Gram-positive and Gram-negative bacterial species.

    Science.gov (United States)

    Farrell, David J; Robbins, Marion; Rhys-Williams, William; Love, William G

    2010-06-01

    The antibacterial activity of XF-73, a dicationic porphyrin drug, was investigated against a range of Gram-positive and Gram-negative bacteria with known antibiotic resistance profiles, including resistance to cell wall synthesis, protein synthesis, and DNA and RNA synthesis inhibitors as well as cell membrane-active antibiotics. Antibiotic-sensitive strains for each of the bacterial species tested were also included for comparison purposes. XF-73 was active [minimum inhibitory concentration (MIC) 0.25-4 mg/L] against all of the Gram-positive bacteria tested, irrespective of the antibiotic resistance profile of the isolates, suggesting that the mechanism of action of XF-73 is unique compared with the major antibiotic classes. Gram-negative activity was lower (MIC 1 mg/L to > 64 mg/L). Minimum bactericidal concentration data confirmed that the activity of XF-73 was bactericidal. Time-kill kinetics against healthcare-associated and community-associated meticillin-resistant Staphylococcus aureus isolates demonstrated that XF-73 was rapidly bactericidal, with > 5 log(10) kill obtained after 15 min at 2 x MIC, the earliest time point sampled. The post-antibiotic effect (PAE) for XF-73 under conditions where the PAE for vancomycin was 5.4 h. XF-73 represents a novel broad-spectrum Gram-positive antibacterial drug with potentially beneficial characteristics for the treatment and prevention of Gram-positive bacterial infections. 2010. Published by Elsevier B.V.

  17. Amplifiable DNA from Gram-negative and Gram-positive bacteria by a low strength pulsed electric field method

    Science.gov (United States)

    Vitzthum, Frank; Geiger, Georg; Bisswanger, Hans; Elkine, Bentsian; Brunner, Herwig; Bernhagen, Jürgen

    2000-01-01

    An efficient electric field-based procedure for cell disruption and DNA isolation is described. Isoosmotic suspensions of Gram-negative and Gram-positive bacteria were treated with pulsed electric fields of Pulses had an exponential decay waveform with a time constant of 3.4 µs. DNA yield was linearly dependent on time or pulse number, with several thousand pulses needed. Electrochemical side-effects and electrophoresis were minimal. The lysates contained non-fragmented DNA which was readily amplifiable by PCR. As the method was not limited to samples of high specific resistance, it should be applicable to physiological fluids and be useful for genomic and DNA diagnostic applications. PMID:10734214

  18. Comparative activity of tigecycline and tetracycline on Gram-negative and Gram-positive bacteria revealed by a multicentre study in four North European countries

    DEFF Research Database (Denmark)

    Nilsson, Lennart E; Frimodt-Møller, Niels; Vaara, Martti

    2011-01-01

    This study involves a multicentre surveillance of tigecycline and tetracycline activity against Gram-negative and Gram-positive bacteria from primary care centres (PCCs), general hospital wards (GHWs) and intensive care units (ICUs) in Denmark (n = 9), Finland (n = 10), Norway (n = 7) and Sweden (n...

  19. Prevalence of AmpC β-lactamase among Gram-negative bacteria ...

    African Journals Online (AJOL)

    Purpose: Infections caused by AmpC-positive bacteria results in high patient morbidity and mortality making their detection clinically important as they cannot be detected in routine susceptibility testing. This study aim to determine the prevalence of AmpC β-lactamase among Gram negative bacteria recovered from clinical ...

  20. Effect of plasmapheresis on the immune system in endotoxin-induced sepsis

    DEFF Research Database (Denmark)

    Toft, P; Schmidt, R; Broechner, A C

    2008-01-01

    BACKGROUND: It has been proposed that plasmapheresis is most effective when applied early in Gram-negative sepsis. We therefore studied the effect of early plasmapheresis on immunity in experimental Escherichia coli endotoxin-induced sepsis. METHODS: 20 pigs received 30 microg/kg of E. coli...... endotoxin. 40 min later, half of the pigs were treated with plasmapheresis which lasted 4 h. The adhesion molecules, the oxidative burst, the number of neutrophils in blood and lungs, and cytokines were measured. RESULTS: Infusion of endotoxin was associated with activation of adhesion molecules increased...... oxidative burst, increased concentration of cytokine, and accumulation of granulocytes in lung tissue. Plasmapheresis reduced the oxidative burst, and there was a tendency towards a reduced accumulation of granulocytes in the lung. CONCLUSION: Though plasmapheresis was initiated early after the endotoxin...

  1. Restriction of cephalosporins and control of extended spectrum beta-lactamase producing gram negative bacteria in a neonatal intensive care unit.

    Science.gov (United States)

    Murki, Srinivas; Jonnala, Sravanthi; Mohammed, Faheemuddin; Reddy, Anupama

    2010-09-01

    This interventional study with historical controls was conducted to study the effect of cephalosporin restriction on the incidence of extended spectrum beta-lactamase (ESBL) gram negative infections in neonates admitted to intensive care unit. All gram negative isolates from the blood were evaluated for beta lactamase production. The incidence of ESBL production was compared before (year 2007) and after cephalosporin restriction (year 2008). Thirty two neonates (3% of NICU admissions) in the year 2007 and fifty six (5.2%) in the year 2008, had gram negative septicemia. The incidence of ESBL gram negatives decreased by 22% (47% to 25%, P=0.03). Restriction of all class of cephalosporins significantly decreased the incidence of ESBL gram negative infections.

  2. Gram staining.

    Science.gov (United States)

    Coico, Richard

    2005-10-01

    Named after Hans Christian Gram who developed the method in 1884, the Gram stain allows one to distinguish between Gram-positive and Gram-negative bacteria on the basis of differential staining with a crystal violet-iodine complex and a safranin counterstain. The cell walls of Gram-positive organisms retain this complex after treatment with alcohol and appear purple, whereas gram-negative organisms decolorize following such treatment and appear pink. The method described here is useful for assessing bacterial contamination of tissue culture samples or for examining the Gram stain status and morphological features of bacteria isolated from mixed or isolated bacterial cultures.

  3. Functional characterisation of Burkholderia pseudomallei biotin protein ligase: A toolkit for anti-melioidosis drug development.

    Science.gov (United States)

    Bond, Thomas E H; Sorenson, Alanna E; Schaeffer, Patrick M

    2017-06-01

    Burkholderia pseudomallei (Bp) is the causative agent of melioidosis. The bacterium is responsible for 20% of community-acquired sepsis cases and 40% of sepsis-related mortalities in northeast Thailand, and is intrinsically resistant to aminoglycosides, macrolides, rifamycins, cephalosporins, and nonureidopenicillins. There is no vaccine and its diagnosis is problematic. Biotin protein ligase (BirA) which is essential for fatty acid synthesis has been proposed as a drug target in bacteria. Very few bacterial BirA have been characterized, and a better understanding of these enzymes is necessary to further assess their value as drug targets. BirA within the Burkholderia genus have not yet been investigated. We present for the first time the cloning, expression, purification and functional characterisation of the putative Bp BirA and orthologous B. thailandensis (Bt) biotin carboxyl carrier protein (BCCP) substrate. A GFP-tagged Bp BirA was produced and applied for the development of a high-throughput (HT) assay based on our differential scanning fluorimetry of GFP-tagged proteins (DSF-GTP) principle as well as an electrophoretic mobility shift assay. Our biochemical data in combination with the new HT DSF-GTP and biotinylation activity assay could facilitate future drug screening efforts against this drug-resistant organism. Copyright © 2017 Elsevier GmbH. All rights reserved.

  4. NDM 1 Gene Carrying Gram negative Bacteria Isolated from Rats ...

    African Journals Online (AJOL)

    In this study, we screened 56 Gram negative bacteria comprising: 3 isolates of Enterobacter ludwigii, 30 Pseudomonas aeruginosa, 22 Proteus mirabilis, and 1 Aeromonas caviae isolated from oral cavity and rectum of rats captured from commercial poultry houses in Ibadan, Oyo State, Nigeria that were resistant to at least ...

  5. Human melioidosis reported by ProMED

    Directory of Open Access Journals (Sweden)

    Katherinn Melissa Nasner-Posso

    2015-06-01

    Conclusions: Internet-based reporting systems such as ProMED are useful to gather information and synthesize knowledge on emerging infections. Although certain areas need to be improved, ProMED provided good information about melioidosis.

  6. The Growing Threat of Multidrug-Resistant Gram-Negative Infections in Patients with Hematologic Malignancies

    Science.gov (United States)

    Baker, Thomas M.; Satlin, Michael J.

    2016-01-01

    Prolonged neutropenia and chemotherapy-induced mucositis render patients with hematologic malignancies highly vulnerable to Gram-negative bacteremia. Unfortunately, multidrug-resistant (MDR) Gram-negative bacteria are increasingly encountered globally, and current guidelines for empirical antibiotic coverage in these patients may not adequately treat these bacteria. This expansion of resistance, coupled with traditional culturing techniques requiring 2-4 days for bacterial identification and antimicrobial susceptibility results, have grave implications for these immunocompromised hosts. This review characterizes the epidemiology, risk factors, resistance mechanisms, recommended treatments, and outcomes of the MDR Gram-negative bacteria that commonly cause infections in patients with hematologic malignancies. We also examine infection prevention strategies in hematology patients, such as infection control practices, antimicrobial stewardship, and targeted decolonization. Finally, we assess strategies to improve outcomes of infected patients, including gastrointestinal screening to guide empirical antibiotic therapy, new rapid diagnostic tools for expeditious identification of MDR pathogens, and use of two new antimicrobial agents, ceftolozane/tazobactam and ceftazidime/avibactam. PMID:27339405

  7. Integrating rapid diagnostics and antimicrobial stewardship improves outcomes in patients with antibiotic-resistant Gram-negative bacteremia.

    Science.gov (United States)

    Perez, Katherine K; Olsen, Randall J; Musick, William L; Cernoch, Patricia L; Davis, James R; Peterson, Leif E; Musser, James M

    2014-09-01

    An intervention for Gram-negative bloodstream infections that integrated mass spectrometry technology for rapid diagnosis with antimicrobial stewardship oversight significantly improved patient outcomes and reduced hospital costs. As antibiotic resistance rates continue to grow at an alarming speed, the current study was undertaken to assess the impact of this intervention in a challenging patient population with bloodstream infections caused by antibiotic-resistant Gram-negative bacteria. A total of 153 patients with antibiotic-resistant Gram-negative bacteremia hospitalized prior to the study intervention were compared to 112 patients treated post-implementation. Outcomes assessed included time to optimal antibiotic therapy, time to active treatment when inactive, hospital and intensive care unit length of stay, all-cause 30-day mortality, and total hospital expenditures. Integrating rapid diagnostics with antimicrobial stewardship improved time to optimal antibiotic therapy (80.9 h in the pre-intervention period versus 23.2 h in the intervention period, P Gram-negatives. The intervention decreased hospital and intensive care unit length of stay, total hospital costs, and reduced all-cause 30-day mortality. Copyright © 2014. Published by Elsevier Ltd.

  8. Performance of Gram staining on blood cultures flagged negative by an automated blood culture system.

    Science.gov (United States)

    Peretz, A; Isakovich, N; Pastukh, N; Koifman, A; Glyatman, T; Brodsky, D

    2015-08-01

    Blood is one of the most important specimens sent to a microbiology laboratory for culture. Most blood cultures are incubated for 5-7 days, except in cases where there is a suspicion of infection caused by microorganisms that proliferate slowly, or infections expressed by a small number of bacteria in the bloodstream. Therefore, at the end of incubation, misidentification of positive cultures and false-negative results are a real possibility. The aim of this work was to perform a confirmation by Gram staining of the lack of any microorganisms in blood cultures that were identified as negative by the BACTEC™ FX system at the end of incubation. All bottles defined as negative by the BACTEC FX system were Gram-stained using an automatic device and inoculated on solid growth media. In our work, 15 cultures that were defined as negative by the BACTEC FX system at the end of the incubation were found to contain microorganisms when Gram-stained. The main characteristic of most bacteria and fungi growing in the culture bottles that were defined as negative was slow growth. This finding raises a problematic issue concerning the need to perform Gram staining of all blood cultures, which could overload the routine laboratory work, especially laboratories serving large medical centers and receiving a large number of blood cultures.

  9. Association of late-onset neonatal sepsis with late neurodevelopment in the first two years of life of preterm infants with very low birth weight

    Directory of Open Access Journals (Sweden)

    Claudia Regina Hentges

    2014-01-01

    Full Text Available OBJECTIVE: To establish the influence of late-onset sepsis on neurodevelopment of preterm infants with very low birth weight (VLBW, according to the etiologic agent METHOD: This was a cohort of newborns with birth weight < 1,500 g and gestational age less than 32 weeks, admitted to the institutional intensive care unit (ICU with up to 48 hours of life, and followed-up at the outpatient follow-up clinic for preterm infants with VLBW until 2 years of corrected age. Exclusion criteria: death within the first 72 hours of life, congenital malformations and genetic syndromes, children with congenital infection by the human immunodeficiency virus (HIV, congenital infection (STORCH, presence of early-onset spesis and cases with more than one pathogen growth in blood cultures. Septic and non-septic infants were compared regarding neonatal outcomes and mortality. Neurodevelopment was assessed using the Bayley Scale (BSDI-II at 18 to 24 months of corrected age. RESULTS: 411 preterm infants with VLBW were eligible; the mean gestational age was 29 ± 2.2 weeks and mean birth weight was 1,041 ± 281grams. Late-onset sepsis occurred in 94 preterm infants with VLBW (22.8%. VLBW infants with Gram-positive infection showed motor deficit when compared to the non-septic group, 68.8% vs. 29.3%, respectively (OR 6; 1.6-21.8, p = 0.006; the cognitive development was similar between the groups. The overall mortality rate from infection was 26.7%; considering the pathogens, the rates were 18.7% for coagulase-negative Staphylococcus, 21.8% for Gram-positive bacteria, and 50% for Gram-negative bacteria and fungi. CONCLUSION: Neonatal sepsis has a significant influence on late neurodevelopment at 2 years of corrected age in preterm infants with VLBW, and Gram-positive infections are associated with motor deficit.

  10. Pediatric melioidosis in Sarawak, Malaysia: Epidemiological, clinical and microbiological characteristics.

    Science.gov (United States)

    Mohan, Anand; Podin, Yuwana; Tai, Nickson; Chieng, Chae-Hee; Rigas, Vanessa; Machunter, Barbara; Mayo, Mark; Wong, Desiree; Chien, Su-Lin; Tan, Lee-See; Goh, Charles; Bantin, Reginal; Mijen, Alexander; Chua, Wen-Yi; Hii, King-Ching; Wong, See-Chang; Ngian, Hie-Ung; Wong, Jin-Shyan; Hashim, Jamilah; Currie, Bart J; Ooi, Mong-How

    2017-06-01

    Melioidosis is a serious, and potentially fatal community-acquired infection endemic to northern Australia and Southeast Asia, including Sarawak, Malaysia. The disease, caused by the usually intrinsically aminoglycoside-resistant Burkholderia pseudomallei, most commonly affects adults with predisposing risk factors. There are limited data on pediatric melioidosis in Sarawak. A part prospective, part retrospective study of children aged Sarawak between 2009 and 2014. We examined epidemiological, clinical and microbiological characteristics. Forty-two patients were recruited during the 6-year study period. The overall annual incidence was estimated to be 4.1 per 100,000 children Sarawak has a very high incidence of pediatric melioidosis, caused predominantly by gentamicin-susceptible B. pseudomallei strains. Children frequently presented with disseminated disease and had an alarmingly high death rate, despite the absence of any apparent predisposing risk factor.

  11. Curative Treatment of Severe Gram-Negative Bacterial Infections by a New Class of Antibiotics Targeting LpxC

    Directory of Open Access Journals (Sweden)

    Nadine Lemaître

    2017-07-01

    Full Text Available The infectious diseases caused by multidrug-resistant bacteria pose serious threats to humankind. It has been suggested that an antibiotic targeting LpxC of the lipid A biosynthetic pathway in Gram-negative bacteria is a promising strategy for curing Gram-negative bacterial infections. However, experimental proof of this concept is lacking. Here, we describe our discovery and characterization of a biphenylacetylene-based inhibitor of LpxC, an essential enzyme in the biosynthesis of the lipid A component of the outer membrane of Gram-negative bacteria. The compound LPC-069 has no known adverse effects in mice and is effective in vitro against a broad panel of Gram-negative clinical isolates, including several multiresistant and extremely drug-resistant strains involved in nosocomial infections. Furthermore, LPC-069 is curative in a murine model of one of the most severe human diseases, bubonic plague, which is caused by the Gram-negative bacterium Yersinia pestis. Our results demonstrate the safety and efficacy of LpxC inhibitors as a new class of antibiotic against fatal infections caused by extremely virulent pathogens. The present findings also highlight the potential of LpxC inhibitors for clinical development as therapeutics for infections caused by multidrug-resistant bacteria.

  12. Extended spectrum β-lactamases, carbapenemases and mobile genetic elements responsible for antibiotics resistance in Gram-negative bacteria.

    Science.gov (United States)

    El Salabi, Allaaeddin; Walsh, Timothey R; Chouchani, Chedly

    2013-05-01

    Infectious diseases due to Gram-negative bacteria are a leading cause of morbidity and mortality worldwide. Antimicrobial agents represent one major therapeutic tools implicated to treat these infections. The misuse of antimicrobial agents has resulted in the emergence of resistant strains of Gram-negatives in particular Enterobacteriaceae and non-fermenters; they have an effect not only on a human but on the public health when bacteria use the resistance mechanisms to spread in the hospital environment and to the community outside the hospitals by means of mobile genetic elements. Gram-negative bacteria have become increasingly resistant to antimicrobial agents. They have developed several mechanisms by which they can withstand to antimicrobials, these mechanisms include the production of Extended-spectrum β-lactamases (ESBLs) and carbapenemases, furthermore, Gram-negative bacteria are now capable of spreading such resistance between members of the family Enterobacteriaceae and non-fermenters using mobile genetic elements as vehicles for such resistance mechanisms rendering antibiotics useless. Therefore, addressing the issue of mechanisms of antimicrobial resistance is considered one of most urgent priorities. This review will help to illustrate different resistance mechanisms; ESBLs, carbapenemases encoded by genes carried by mobile genetic elements, which are used by Gram-negative bacteria to escape antimicrobial effect.

  13. Lipoproteins/peptides are sepsis-inducing toxins from bacteria that can be neutralized by synthetic anti-endotoxin peptides.

    Science.gov (United States)

    Martinez de Tejada, Guillermo; Heinbockel, Lena; Ferrer-Espada, Raquel; Heine, Holger; Alexander, Christian; Bárcena-Varela, Sergio; Goldmann, Torsten; Correa, Wilmar; Wiesmüller, Karl-Heinz; Gisch, Nicolas; Sánchez-Gómez, Susana; Fukuoka, Satoshi; Schürholz, Tobias; Gutsmann, Thomas; Brandenburg, Klaus

    2015-09-22

    Sepsis, a life-threatening syndrome with increasing incidence worldwide, is triggered by an overwhelming inflammation induced by microbial toxins released into the bloodstream during infection. A well-known sepsis-inducing factor is the membrane constituent of Gram-negative bacteria, lipopolysaccharide (LPS), signalling via Toll-like receptor-4. Although sepsis is caused in more than 50% cases by Gram-positive and mycoplasma cells, the causative compounds are still poorly described. In contradicting investigations lipoproteins/-peptides (LP), lipoteichoic acids (LTA), and peptidoglycans (PGN), were made responsible for eliciting this pathology. Here, we used human mononuclear cells from healthy donors to determine the cytokine-inducing activity of various LPs from different bacterial origin, synthetic and natural, and compared their activity with that of natural LTA and PGN. We demonstrate that LP are the most potent non-LPS pro-inflammatory toxins of the bacterial cell walls, signalling via Toll-like receptor-2, not only in vitro, but also when inoculated into mice: A synthetic LP caused sepsis-related pathological symptoms in a dose-response manner. Additionally, these mice produced pro-inflammatory cytokines characteristic of a septic reaction. Importantly, the recently designed polypeptide Aspidasept(®) which has been proven to efficiently neutralize LPS in vivo, inhibited cytokines induced by the various non-LPS compounds protecting animals from the pro-inflammatory activity of synthetic LP.

  14. ClubSub-P: Cluster-Based Subcellular Localization Prediction for Gram-Negative Bacteria and Archaea

    Science.gov (United States)

    Paramasivam, Nagarajan; Linke, Dirk

    2011-01-01

    The subcellular localization (SCL) of proteins provides important clues to their function in a cell. In our efforts to predict useful vaccine targets against Gram-negative bacteria, we noticed that misannotated start codons frequently lead to wrongly assigned SCLs. This and other problems in SCL prediction, such as the relatively high false-positive and false-negative rates of some tools, can be avoided by applying multiple prediction tools to groups of homologous proteins. Here we present ClubSub-P, an online database that combines existing SCL prediction tools into a consensus pipeline from more than 600 proteomes of fully sequenced microorganisms. On top of the consensus prediction at the level of single sequences, the tool uses clusters of homologous proteins from Gram-negative bacteria and from Archaea to eliminate false-positive and false-negative predictions. ClubSub-P can assign the SCL of proteins from Gram-negative bacteria and Archaea with high precision. The database is searchable, and can easily be expanded using either new bacterial genomes or new prediction tools as they become available. This will further improve the performance of the SCL prediction, as well as the detection of misannotated start codons and other annotation errors. ClubSub-P is available online at http://toolkit.tuebingen.mpg.de/clubsubp/ PMID:22073040

  15. Protein secretion and membrane insertion systems in gram-negative bacteria.

    Science.gov (United States)

    Saier, Milton H

    2006-01-01

    In contrast to other organisms, gram-negative bacteria have evolved numerous systems for protein export. Eight types are known that mediate export across or insertion into the cytoplasmic membrane, while eight specifically mediate export across or insertion into the outer membrane. Three of the former secretory pathway (SP) systems, type I SP (ISP, ABC), IIISP (Fla/Path) and IVSP (Conj/Vir), can export proteins across both membranes in a single energy-coupled step. A fourth generalized mechanism for exporting proteins across the two-membrane envelope in two distinct steps (which we here refer to as type II secretory pathways [IISP]) utilizes either the general secretory pathway (GSP or Sec) or the twin-arginine targeting translocase for translocation across the inner membrane, and either the main terminal branch or one of several protein-specific export systems for translocation across the outer membrane. We here survey the various well-characterized protein translocation systems found in living organisms and then focus on the systems present in gram-negative bacteria. Comparisons between these systems suggest specific biogenic, mechanistic and evolutionary similarities as well as major differences.

  16. Metallo- β-lactamases among Multidrug Resistant (MDR Gram Negative Bacteria Isolated from Clinical Specimens during 2009 in Sanandaj, Kurdistan Province

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    Himen Salimizand

    2012-08-01

    Full Text Available Background: Today, there are numerous reports about emerging multi drug resistant gram negative bacteria all around the world, especially in ICUs. Rarely, Metallo-β-lactamase (MBL enzymes are responsible for these cases. Study of MBLs for diagnosing and preventing distribution of the origin of infection are critical issues. In addition, we would like to compare the efficacy of Iranian and foreign- made antibiotic disks. Materials and Methods: During 2009 all entered clinical specimens to the laboratory tested for detecting gram negative bacteria. Isolated bacteria were tested by Kirby-Bauer method to antibiotic susceptibility test by Iranian and foreign (MAST disks. For gram negative carbapenem resistant isolates, PCR technique used to detect VIM, GIM, and SIM variants of MBLs.Results: During one year, 17890 clinical specimens referred Besat laboratory. The most specimen was Urine (8172 followed by blood culture (5190 that in which 1110 gram negative and positives isolated. Out of which, 778 (70% of isolates were gram negatives. MDR gram negatives were 157 (20.2%. Imipenem and meropenem were the most efficient antibiotics (all susceptible and ceftriaxone was the least (19 % susceptible. E. coli was the most prevalent isolate. 79 Gram negative isolates (10.1% were resistant to Iranian-made discs but all susceptible for foreign ones. All 79 isolates were tested by PCR for MBL genes, that, all were negative. Besides, Iranian imipenem and cefepime disks have had distinguishable difference in susceptibility of isolates.Conclusion: Fortunately, none of gram negative isolates were MBL producer, which revealed no colonization of MBL producing bacteria. Iranian-made disks appear efficient except for imipenem and cefepime.

  17. Risk factors for carbapenem resistant bacteraemia and mortality due to gram negative bacteraemia in a developing country

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    Kalam, K.; Kumar, S.; Ali, S.; Baqi, S.; Qamar, F.

    2014-01-01

    Objective: To identify the risk factors for carbapenem resistant bacteraemia and mortality due to gram negative bacteraemia in a developing country. Methods: A prospective cohort study was conducted at the Sindh Institute of Urology and Transplantation (SIUT) from June to October 2012. Hospitalized patients > 15 years of age with gram negative bacteraemia were included and followed for a period of 2 weeks for in hospital mortality. Data was collected and analyzed for 243 subjects. Multivariate analysis was used to determine the risk factors for carbapenem resistant bacteraemia and mortality due to gram negative bacteraemia. Crude and adjusted odds ratio and 95% CI are reported. Results: A total of 729 out of 1535 (47.5%) cultures were positive for gram negative isolates. Out of 243 subjects, 117 (48%) had an MDR isolate. Having an MDR isolate on culture (AOR, 2.33; 95% CI, 1.35 -4.0), having multiple positive cultures (AOR, 1.8; 95% CI, 0.94 -3.4) and stay in ICU >48 hours (AOR, 2.0 ; 95% CI, 1.12 -3.78) were identified as significant risk factors for mortality due to gram negative organisms. Risk factors for carbapenem resistant bacteraemia were age >50 years (AOR, 1.83; 95% CI, 1.0-3.5), septic shock on presentation (AOR 2.53; 95% CI, 1.03 -6.2) , ICU stay of >72 hours (AOR 2.40; 95% CI, 1.14-5.0) and receiving immunosuppressant medications (AOR 2.23; 95% CI, 0.74 - 6.7). Conclusion: There is a high burden of MDR and carbapenem resistant gram negative bacteraemia, with a high mortality rate. (author)

  18. Subcellular localization for Gram positive and Gram negative bacterial proteins using linear interpolation smoothing model.

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    Saini, Harsh; Raicar, Gaurav; Dehzangi, Abdollah; Lal, Sunil; Sharma, Alok

    2015-12-07

    Protein subcellular localization is an important topic in proteomics since it is related to a protein׳s overall function, helps in the understanding of metabolic pathways, and in drug design and discovery. In this paper, a basic approximation technique from natural language processing called the linear interpolation smoothing model is applied for predicting protein subcellular localizations. The proposed approach extracts features from syntactical information in protein sequences to build probabilistic profiles using dependency models, which are used in linear interpolation to determine how likely is a sequence to belong to a particular subcellular location. This technique builds a statistical model based on maximum likelihood. It is able to deal effectively with high dimensionality that hinders other traditional classifiers such as Support Vector Machines or k-Nearest Neighbours without sacrificing performance. This approach has been evaluated by predicting subcellular localizations of Gram positive and Gram negative bacterial proteins. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Airborne Transmission of Melioidosis to Humans from Environmental Aerosols Contaminated with B. pseudomallei.

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    Chen, Pei-Shih; Chen, Yao-Shen; Lin, Hsi-Hsun; Liu, Pei-Ju; Ni, Wei-Fan; Hsueh, Pei-Tan; Liang, Shih-Hsiung; Chen, Chialin; Chen, Ya-Lei

    2015-06-01

    Melioidosis results from an infection with the soil-borne pathogen Burkholderia pseudomallei, and cases of melioidosis usually cluster after rains or a typhoon. In an endemic area of Taiwan, B. pseudomallei is primarily geographically distributed in cropped fields in the northwest of this area, whereas melioidosis cases are distributed in a densely populated district in the southeast. We hypothesized that contaminated cropped fields generated aerosols contaminated with B. pseudomallei, which were carried by a northwesterly wind to the densely populated southeastern district. We collected soil and aerosol samples from a 72 km2 area of land, including the melioidosis-clustered area and its surroundings. Aerosols that contained B. pseudomallei-specific TTSS (type III secretion system) ORF2 DNA were well distributed in the endemic area but were rare in the surrounding areas during the rainy season. The concentration of this specific DNA in aerosols was positively correlated with the incidence of melioidosis and the appearance of a northwesterly wind. Moreover, the isolation rate in the superficial layers of the contaminated cropped field in the northwest was correlated with PCR positivity for aerosols collected from the southeast over a 2-year period. According to pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) analyses, PFGE Type Ia (ST58) was the predominant pattern linking the molecular association among soil, aerosol and human isolates. Thus, the airborne transmission of melioidosis moves from the contaminated soil to aerosols and/or to humans in this endemic area.

  20. The Role of Monitoring Gentamicin Levels in Patients with Gram-Negative Peritoneal Dialysis-Associated Peritonitis

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    Tang, Wen; Cho, Yeoungjee; Hawley, Carmel M.; Badve, Sunil V.; Johnson, David W.

    2014-01-01

    ♦ Background: There is limited available evidence regarding the role of monitoring serum gentamicin concentrations in peritoneal dialysis (PD) patients receiving this antimicrobial agent in gram-negative PD-associated peritonitis. ♦ Methods: Using data collected in all patients receiving PD at a single center who experienced a gram-negative peritonitis episode between 1 January 2005 and 31 December 2011, we investigated the relationship between measured serum gentamicin levels on day 2 following initial empiric antibiotic therapy and subsequent clinical outcomes of confirmed gram-negative peritonitis. ♦ Results: Serum gentamicin levels were performed on day 2 in 51 (77%) of 66 first gram-negative peritonitis episodes. Average serum gentamicin levels on day 2 were 1.83 ± 0.84 mg/L with levels exceeding 2 mg/L in 22 (43%) cases. The overall cure rate was 64%. No cases of ototoxicity were observed. Day-2 gentamicin levels were not significantly different between patients who did and did not have a complication or cure. Using multivariable logistic regression analysis, failure to cure peritonitis was not associated with either day-2 gentamicin level (adjusted odds ratio (OR) 0.96, 95% confidence interval (CI) 0.25 - 3.73) or continuation of gentamicin therapy beyond day 2 (OR 0.28, 0.02 - 3.56). The only exception was polymicrobial peritonitis, where day-2 gentamicin levels were significantly higher in episodes that were cured (2.06 ± 0.41 vs 1.29 ± 0.71, p = 0.01). In 17 (26%) patients receiving extended gentamicin therapy, day-5 gentamicin levels were not significantly related to peritonitis cure. ♦ Conclusion: Day-2 gentamicin levels did not predict gentamicin-related harm or efficacy during short-course gentamicin therapy for gram-negative PD-related peritonitis, except in cases of polymicrobial peritonitis, where higher levels were associated with cure. PMID:24385334

  1. Antimicrobial resistance pattern of Gramnegative bacilli isolated of Vali-Asr Hospital wards in Arak

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    Farshid Didgar

    2014-11-01

    Full Text Available Background: Infectious diseases are of the most important causes of mortality all around the world particular in developing countries. Recently, the most important thing that has worried medical society is antibiotic resistance. Multi-resistant gram_negative rods are important pathogens in hospitals, causing high rate of mortality.The main goal of this study was to investigate the antimicrobial resistance patterns among common gram-negative bacilli isolated from patients of Vali-Asr Hospital. Material and Methods: This is a cross-sectional descriptive study conducted between the years 2010-2012 in Vali-Asr hospital in Arak. In this study 1120 specimen were examined. Bacterial strains were isolated by conventional methods from various clinical samples of patients including: blood, urine, wound, sputum, CSF, andetc.All isolates were examined for antimicrobial resistance using disc diffusion method. Results: In this study 737 specimen were positive cultures. A total of 332 isolates of Gram-negative bacilli were identified. The most frequent gram negative bacteria were isolated from urine, wound, blood, respiratory secretion and catheter. The most frequent pathogens were E.coli followed by k.pneumonia, entrobacter, p.oaeruginosa, Acinetobacter spp, citrobacter and proteus. High rate of resistance to third generation of cephalospoins & carbapenems observed amang isolates of Acintobacter spp.Prodution of extended spectrum beralactamases (ESBLS was found in 51.4% of all Gram negative bacteria. Conclusion: Antibiotic resistance, particularly multi-drug resistance is frequent among microorganisms of ValiAsr Hospital. Resistance in our country, like other countries have been shown to be increased, so it is highly recommended to prohibit unnecessary prescription of antibiotics.

  2. Imported melioidosis in Japan: a review of cases

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    Hadano Y

    2018-01-01

    Full Text Available Yoshiro Hadano Department of Infectious Diseases, St. Mary’s Hospital, Kurume, Fukuoka, Japan Abstract: Fourteen cases of reported melioidosis in Japan were reviewed. The mean age was 52.4 years (33–69 years, and all patients were male. All of the presumed exposures originated in Southeast Asia. The most common underlying disease was diabetes mellitus, including those patients with impaired glucose tolerance (n=8. As for mode of onset, 13 patients had acute infections and one had chronic infection. Of these 14 patients, the most common infection site on admission was lung (n=8, followed by bone (n=5, skin (n=4, gastrointestinal abscess formation (n=3, urinary tract (n=3, aorta (n=2, mediastinal lymph node swelling (n=1, and central nervous system (n=1. Bacteremia was observed in nine patients, and Burkholderia pseudomallei isolates were mostly susceptible to ceftazidime and carbapenem. Overall mortality was 14.3%. Melioidosis is a rare infection in Japan, with all known cases to date having been imported from Southeast Asia. Diabetes was a common risk factor. Keywords: melioidosis, Burkholderia pseudomallei, Japan, Southeast Asia 

  3. Effect of Linezolid on the 50% Lethal Dose and 50% Protective Dose in Treatment of Infections by Gram-Negative Pathogens in Naive and Immunosuppressed Mice and on the Efficacy of Ciprofloxacin in an Acute Murine Model of Septicemia

    Science.gov (United States)

    Marra, Andrea; Lamb, Lucinda; Medina, Ivette; George, David; Gibson, Glenn; Hardink, Joel; Rugg, Jady; Van Deusen, Jeffrey

    2012-01-01

    Murine models of infection were used to study the effect of linezolid on the virulence of Gram-negative bacteria and to assess potential pharmacodynamic interactions with ciprofloxacin in the treatment of these infections, prompted by observations from a recent clinical trial. Naive and immunosuppressed mice were challenged with Klebsiella pneumoniae 53A1109, K. pneumoniae GC6658, and Pseudomonas aeruginosa UC12120 in acute sepsis and pulmonary infection models, using different serial dilutions of these pathogens (groups of 8 animals each). Linezolid (100 mg/kg/dose) was administered orally at 0.5 and 4.0 h postchallenge in the sepsis model and at 4 h postchallenge followed by 2 days of twice-daily treatment in the pulmonary model. Further, ciprofloxacin alone and in combination with oral linezolid was investigated in the sepsis model. Survival was assessed for 4 and 10 days postchallenge in the systemic and respiratory models, respectively. The data were fitted to a nonlinear regression analysis to determine 50% lethal doses (LD50s) and 50% protective doses (PD50s). A clinically relevant, high-dose regimen of linezolid had no significant effect on LD50 in these models. This lack of effect was independent of immune status. A combination of oral ciprofloxacin with linezolid yielded lower PD50s than oral ciprofloxacin alone (ciprofloxacin in combination, 8.4 to 32.7 mg/kg; oral ciprofloxacin, 39.4 to 88.3 mg/kg). Linezolid did not improve the efficacy of subcutaneous ciprofloxacin (ciprofloxacin in combination, 2.0 to 2.4 mg/kg; subcutaneous ciprofloxacin, 2.0 to 2.8 mg/kg). In conclusion, linezolid does not seem to potentiate infections caused by Gram-negative pathogens or to interact antagonistically with ciprofloxacin. PMID:22710118

  4. ClubSub-P: Cluster-based subcellular localization prediction for Gram-negative bacteria and Archaea.

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    Nagarajan eParamasivam

    2011-11-01

    Full Text Available The subcellular localization of proteins provides important clues to their function in a cell. In our efforts to predict useful vaccine targets against Gram-negative bacteria, we noticed that misannotated start codons frequently lead to wrongly assigned subcellular localizations. This and other problems in subcellular localization prediction, such as the relatively high false positive and false negative rates of some tools, can be avoided by applying multiple prediction tools to groups of homologous proteins. Here we present ClubSub-P, an online database that combines existing subcellular localization prediction tools into a consensus pipeline from more than 600 proteomes of fully sequenced microorganisms. On top of the consensus prediction at the level of single sequences, the tool uses clusters of homologous proteins from Gram-negative bacteria and from Archaea to eliminate false positive and false negative predictions. ClubSub-P can assign the subcellular localization of proteins from Gram-negative bacteria and Archaea with high precision. The database is searchable, and can easily be expanded using either new bacterial genomes or new prediction tools as they become available. This will further improve the performance of the subcellular localization prediction, as well as the detection of misannotated start codons and other annotation errors. ClubSub-P is available online at http://toolkit.tuebingen.mpg.de/clubsubp/

  5. Development and characterization of a caprine aerosol infection model of melioidosis.

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    Carl Soffler

    Full Text Available Infection with Burkholderia pseudomallei causes the disease melioidosis, which often presents as a serious suppurative infection that is typically fatal without intensive treatment and is a significant emerging infectious disease in Southeast Asia. Despite intensive research there is still much that remains unknown about melioidosis pathogenesis. New animal models of melioidosis are needed to examine novel aspects of pathogenesis as well as for the evaluation of novel therapeutics. The objective of the work presented here was to develop a subacute to chronic caprine model of melioidosis and to characterize the progression of disease with respect to clinical presentation, hematology, clinical microbiology, thoracic radiography, and gross and microscopic pathology. Disease was produced in all animals following an intratracheal aerosol of 10(4 CFU delivered, with variable clinical manifestations indicative of subacute and chronic disease. Bronchointerstitial pneumonia was apparent microscopically by day 2 and radiographically and grossly apparent by day 7 post infection (PI. Early lesions of bronchopneumonia soon progressed to more severe bronchointerstitial pneumonia with pyogranuloma formation. Extrapulmonary dissemination appeared to be a function of pyogranuloma invasion of pulmonary vasculature, which peaked around day 7 PI. Histopathology indicated that leukocytoclastic vasculitis was the central step in dissemination of B. pseudomallei from the lungs as well as in the establishment of new lesions. While higher doses of organism in goats can produce acute fatal disease, the dose investigated and resulting disease had many similarities to human melioidosis and may warrant further development to provide a model for the study of both natural and bioterrorism associated disease.

  6. Determination the bacterial etiologies for sepsis in premature newborns admitted in neonatal intensive care unit

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    Nastaran Khosravi

    2017-02-01

    Full Text Available Background: Bacterial sepsis is a main cause of mortality and morbidity especially in preterm newborns. The aim of this study was to search the bacterial etiologies of neonatal sepsis in NICU admitted preterm neonates. Methods: A descriptive cross-sectional study had done in NICU of Ali Asghar Hospital, Tehran, Iran from March 2007 to March 2009. Seventy septicemic preterm newborns (<37 weeks were studied. At admission day, for blood culture, 1-2 ml of venous blood was drawn after swabbing the venipuncture site with alcohol. After centrifugation of blood samples, deposits were cultured on sheep blood agar and incubated in a candle jar at 37 °C for 48 h and followed by subcultured. Isolates were identified using standard techniques (Nima pouyesh, Iran. Type of isolated bacterial organisms determined. Its correlation with gestational age, birth weight, premature rupture of membranes (PROM and other variables determined we used the nonparametric two independent sample test, Mann-Whitney U test. Chi-square values (CI 95%, P< 0.05 were calculated for all categorical variables. P-value less than 0.05 considered statistically significant. Results: Of 70 studied septicemic preterm cases, 17 (10.6% cases had positive blood culture. Overall gram-negative organisms were more frequent than gram-positive organisms, Klebsiella (K. pneumoniae, Escherichia (E. coli and Staphylococcus (S. aureus organisms were the 3 common causes of bacterial sepsis in studied cases. Early onset sepsis produced by K. pneumonia (40%, E. coli (20% and S. aureus (20%. K. pneumonia, E. coli, S. aureus had equal incidence in late onset sepsis (26.8%. K. pneumonia was more frequent in early onset sepsis (P= 0.05, and in low birth weight (< 1500 g neonates (P= 0.005, and PROM (P= 0.05. Conclusion: Three causes for sepsis in premature newborns were determined: K. pneumonia, E. coli and S. aureus, it is so important for initial antibiotic treatment in admission day. Low birth weight

  7. Pediatric melioidosis in Sarawak, Malaysia: Epidemiological, clinical and microbiological characteristics.

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    Anand Mohan

    2017-06-01

    Full Text Available Melioidosis is a serious, and potentially fatal community-acquired infection endemic to northern Australia and Southeast Asia, including Sarawak, Malaysia. The disease, caused by the usually intrinsically aminoglycoside-resistant Burkholderia pseudomallei, most commonly affects adults with predisposing risk factors. There are limited data on pediatric melioidosis in Sarawak.A part prospective, part retrospective study of children aged <15 years with culture-confirmed melioidosis was conducted in the 3 major public hospitals in Central Sarawak between 2009 and 2014. We examined epidemiological, clinical and microbiological characteristics.Forty-two patients were recruited during the 6-year study period. The overall annual incidence was estimated to be 4.1 per 100,000 children <15 years, with marked variation between districts. No children had pre-existing medical conditions. Twenty-three (55% had disseminated disease, 10 (43% of whom died. The commonest site of infection was the lungs, which occurred in 21 (50% children. Other important sites of infection included lymph nodes, spleen, joints and lacrimal glands. Seven (17% children had bacteremia with no overt focus of infection. Delays in diagnosis and in melioidosis-appropriate antibiotic treatment were observed in nearly 90% of children. Of the clinical isolates tested, 35/36 (97% were susceptible to gentamicin. Of these, all 11 isolates that were genotyped were of a single multi-locus sequence type, ST881, and possessed the putative B. pseudomallei virulence determinants bimABp, fhaB3, and the YLF gene cluster.Central Sarawak has a very high incidence of pediatric melioidosis, caused predominantly by gentamicin-susceptible B. pseudomallei strains. Children frequently presented with disseminated disease and had an alarmingly high death rate, despite the absence of any apparent predisposing risk factor.

  8. The Toll pathway underlies host sexual dimorphism in resistance to both Gram-negative and Gram-positive bacteria in mated Drosophila.

    Science.gov (United States)

    Duneau, David F; Kondolf, Hannah C; Im, Joo Hyun; Ortiz, Gerardo A; Chow, Christopher; Fox, Michael A; Eugénio, Ana T; Revah, J; Buchon, Nicolas; Lazzaro, Brian P

    2017-12-21

    Host sexual dimorphism is being increasingly recognized to generate strong differences in the outcome of infectious disease, but the mechanisms underlying immunological differences between males and females remain poorly characterized. Here, we used Drosophila melanogaster to assess and dissect sexual dimorphism in the innate response to systemic bacterial infection. We demonstrated sexual dimorphism in susceptibility to infection by a broad spectrum of Gram-positive and Gram-negative bacteria. We found that both virgin and mated females are more susceptible than mated males to most, but not all, infections. We investigated in more detail the lower resistance of females to infection with Providencia rettgeri, a Gram-negative bacterium that naturally infects D. melanogaster. We found that females have a higher number of phagocytes than males and that ablation of hemocytes does not eliminate the dimorphism in resistance to P. rettgeri, so the observed dimorphism does not stem from differences in the cellular response. The Imd pathway is critical for the production of antimicrobial peptides in response to Gram-negative bacteria, but mutants for Imd signaling continued to exhibit dimorphism even though both sexes showed strongly reduced resistance. Instead, we found that the Toll pathway is responsible for the dimorphism in resistance. The Toll pathway is dimorphic in genome-wide constitutive gene expression and in induced response to infection. Toll signaling is dimorphic in both constitutive signaling and in induced activation in response to P. rettgeri infection. The dimorphism in pathway activation can be specifically attributed to Persephone-mediated immune stimulation, by which the Toll pathway is triggered in response to pathogen-derived virulence factors. We additionally found that, in absence of Toll signaling, males become more susceptible than females to the Gram-positive Enterococcus faecalis. This reversal in susceptibility between male and female Toll

  9. Doripenem: an expected arrival in the treatment of infections caused by multidrug-resistant Gram-negative pathogens.

    Science.gov (United States)

    Poulakou, Garyphallia; Giamarellou, Helen

    2008-05-01

    Potent new drugs against multidrug-resistant Gram-negative bacteria, namely Pseudomonas aeruginosa and Acinetobacter spp. and pan-drug-resistant Klebsiella pneumoniae, which constitute an increasing medical threat, are almost absent from the future pharmaceutical pipeline. This drug evaluation focuses on the position of doripenem, a novel forthcoming carbapenem. Mechanisms of resistance and new drugs with anti-Gram-negative activity are also briefly reviewed. Literature search was performed for new carbapenems, new antibiotics, doripenem, metallo-beta-lactamase inhibitors, multidrug-resistant pathogens, antipseudomonal antibiotics and multidrug-resistant epidemiology. Doripenem possesses a broad spectrum of activity against Gram-negative bacteria, similar to that of meropenem, while retaining the spectrum of imipenem against Gram-positive pathogens. Against P. aeruginosa, doripenem exhibits rapid bactericidal activity with 2 - 4-fold lower MIC values, compared to meropenem. Exploitation of pharmacokinetic/pharmacodynamic applications could offer a treatment opportunity against strains exhibiting borderline resistance to doripenem. Stability against numerous beta-lactamases, low adverse event potential and more potent in vitro antibacterial activity against P. aeruginosa and A. baumanni compared to the existing carbapenems, are its principal features.

  10. Characterization of carbapenem-resistant Gram-negative bacteria from Tamil Nadu.

    Science.gov (United States)

    Nachimuthu, Ramesh; Subramani, Ramkumar; Maray, Suresh; Gothandam, K M; Sivamangala, Karthikeyan; Manohar, Prasanth; Bozdogan, Bülent

    2016-10-01

    Carbapenem resistance is disseminating worldwide among Gram-negative bacteria. The aim of this study was to identify carbapenem-resistance level and to determine the mechanism of carbapenem resistance among clinical isolates from two centres in Tamil Nadu. In the present study, a total of 93 Gram-negative isolates, which is found to be resistant to carbapenem by disk diffusion test in two centres, were included. All isolates are identified at species level by 16S rRNA sequencing. Minimal inhibitory concentrations (MICs) of isolates for Meropenem were tested by agar dilution method. Presence of blaOXA, blaNDM, blaVIM, blaIMP and blaKPC genes was tested by PCR in all isolates. Amplicons were sequenced for confirmation of the genes. Among 93 isolates, 48 (%52) were Escherichia coli, 10 (%11) Klebsiella pneumoniae, nine (%10) Pseudomonas aeruginosa. Minimal inhibitory concentration results showed that of 93 suspected carbapenem-resistant isolates, 27 had meropenem MICs ≥ 2 μg/ml. The MIC range, MIC50 and MIC90 were 128 μg/ml, 0.12 and 16 μg/ml, respectively. Fig. 1 . Among meropenem-resistant isolates, E. coli were the most common (9/48, 22%), followed by K. pneumoniae (7/9, 77%), P. aeruginosa (6/10, 60%), Acinetobacter baumannii (2/2, 100%), Enterobacter hormaechei (2/3, 67%) and one Providencia rettgeri (1/1, 100%). PCR results showed that 16 of 93 carried blaNDM, three oxa181, and one imp4. Among blaNDM carriers, nine were E. coli, four Klebsiella pneumoniae, two E. hormaechei and one P. rettgeri. Three K. pneumoniae were OXA-181 carriers. The only imp4 carrier was P. aeruginosa. A total of seven carbapenem-resistant isolates were negatives by PCR for the genes studied. All carbapenem-resistance gene-positive isolates had meropenem MICs >2 μg/ml. Our results confirm the dissemination of NDM and emergence of OXA-181 beta-lactamase among Gram-negative bacteria in South India. This study showed the emergence of NDM producer in clinical isolates of E

  11. Resistant gram-negative bacilli and antibiotic consumption in zarqa, jordan

    International Nuclear Information System (INIS)

    Bataineh, H.A.; Alrashed, K.M.

    2007-01-01

    To investigate the prevalence of antibiotic resistance among gram-negative bacteria in relation to antibiotic use in Prince Hashem Hospital (PHH), Jordan. One hundred consecutive gram-negative bacterial isolates from different sites were collected from patients admitted to the ICU at PHH. The susceptibilities of the strains to 12 antibiotics were performed and interpreted. The quantities and the numbers of the patients discharged on antibiotics and the quantities consumed were obtained from the hospital pharmacy records. The most common isolate was P. aeruginosa (n=21) The most common site of isolation was the respiratory tract (65%), The highest susceptibility was to piperacillin/ tazobactam(78%), and the lowest was to cefuroxime(34%). The aminoglycosides gentamicin and amikacin were active against 71% and 73% of the isolates respectively, Ciprofloxacin was active against 75% of the isolates. The most frequently used antibiotics were the third-generation cephalosporins ceftriaxone and ceftazidime, followed by imipenem and amikacin. Antibiotic resistance surveillance programs associated with registration of antibiotic consumption are necessary to promote optimal use of antibiotics. Rational prescribing of antibiotics should be encouraged through educational programs, surveillance and audit. Proper infection control measures should be practiced to prevent horizontal transfer of drug-resistant organisms. (author)

  12. Neuropilin-1highCD4+CD25+ Regulatory T Cells Exhibit Primary Negative Immunoregulation in Sepsis

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    Yu-Lei Gao

    2016-01-01

    Full Text Available Regulatory T cells (Tregs appear to be involved in sepsis-induced immune dysfunction; neuropilin-1 (Nrp-1 was identified as a surface marker for CD4+CD25+Tregs. In the current study, we investigated the negative immunoregulation of Nrp-1highCD4+CD25+Tregs and the potential therapeutic value of Nrp-1 in sepsis. Splenic CD4+CD25+Tregs from cecal ligation and puncture (CLP mouse models were further segregated into Nrp-1highTregs and Nrp-1lowTregs; they were cocultured with CD4+CD25−  T cells. The expression of forkhead/winged helix transcription factor-3 (Foxp-3, cytotoxic T-lymphocyte associated antigen-4 (CTLA-4, membrane associated transforming growth factor-β (TGF-βm+, apoptotic rate, and secretive ability [including TGF-β and interleukin-10 (IL-10] for various types of Tregs, as well as the immunosuppressive ability of Tregs on CD4+CD25−  T cells, were determined. Meanwhile, the impact of recombinant Nrp-1 polyclonal antibody on the demethylation of Foxp-3-TSDR (Treg-specific demethylated region was measured in in vitro study. Sepsis per se markedly promoted the expression of Nrp-1 of CD4+CD25+Tregs. Foxp-3/CTLA-4/TGF-βm+ of Nrp-1highTregs were upregulated by septic challenge. Nrp-1highTregs showed strong resilience to apoptosis and secretive ability and the strongest immunosuppressive ability on CD4+CD25−  T cells. In the presence of lipopolysaccharide (LPS, the recombinant Nrp-1 polyclonal antibody reduced the demethylation of Foxp-3-TSDR. Nrp-1highTregs might reveal primary negative immunoregulation in sepsis; Nrp-1 could represent a new potential therapeutic target for the study of immune regulation in sepsis.

  13. Comparison of the Cathra Repliscan II, the AutoMicrobic system Gram-Negative General Susceptibility-Plus Card, and the Micro-Media System Fox Panel for dilution susceptibility testing of gram-negative bacilli.

    Science.gov (United States)

    Reiber, N E; Kelly, M T; Latimer, J M; Tison, D L; Hysmith, R M

    1985-06-01

    A comparative evaluation was done to test the accuracy of the Cathra Repliscan II agar dilution system (Diagnostic Equipment, Inc., St. Paul, Minn.), the AutoMicrobic system with Gram-Negative General Susceptibility-Plus Card (Vitek Systems, Inc., Hazelwood, Mo.), and the Micro-Media Fox Panel micro broth dilution system (Micro-Media Systems, Inc., San Jose, Calif.) in determining MICs of 12 antibiotics for 200 gram-negative bacilli. Of the 200 strains tested, 12 isolates did not grow in one of the three systems. The 188 remaining organisms included 158 members of the family Enterobacteriaceae, 20 Pseudomonas spp., 5 Acinetobacter sp., 3 Aeromonas spp., and 2 Vibrio spp. A total of 2,256 organism-antibiotic combinations were analyzed for each system. An MIC was considered correct if two of the three systems were in agreement. When disagreements occurred, correct MICs were determined by the standard agar dilution method. With this criterion, overall agreements of the Cathra Repliscan II system, AutoMicrobic system, and Micro-Media Fox Panel system were 94.7, 94.9, and 95.5%, respectively. Tetracycline (20%), nitrofurantoin (20%), and ampicillin (16%) accounted for 56% of the discrepancies observed. These results indicate that all three systems perform with a high degree of accuracy for susceptibility testing of gram-negative bacilli.

  14. Trojan Horse Antibiotics-A Novel Way to Circumvent Gram-Negative Bacterial Resistance?

    Science.gov (United States)

    Tillotson, Glenn S

    2016-01-01

    Antibiotic resistance has been emerged as a major global health problem. In particular, gram-negative species pose a significant clinical challenge as bacteria develop or acquire more resistance mechanisms. Often, these bacteria possess multiple resistance mechanisms, thus nullifying most of the major classes of drugs. Novel approaches to this issue are urgently required. However, the challenges of developing new agents are immense. Introducing novel agents is fraught with hurdles, thus adapting known antibiotic classes by altering their chemical structure could be a way forward. A chemical addition to existing antibiotics known as a siderophore could be a solution to the gram-negative resistance issue. Siderophore molecules rely on the bacterial innate need for iron ions and thus can utilize a Trojan Horse approach to gain access to the bacterial cell. The current approaches to using this potential method are reviewed.

  15. Gram-negative bacteria account for main differences between faecal microbiota from patients with ulcerative colitis and healthy controls

    DEFF Research Database (Denmark)

    Vigsnæs, Louise Kristine; Brynskov, J.; Steenholdt, C.

    2012-01-01

    process of the gut mucosa. The aim of this study was to investigate the faecal microbiota in patients either with UC in remission (n=6) or with active disease (n=6), and in healthy controls (n=6). The composition of Gram-negative bacteria and Gram-positive bacteria was examined. Antigenic structures...... of Gram-negative bacteria such as lipopolysaccharides have been related to the inflammatory responses and pathogenesis of inflammatory bowel disease. Dice cluster analysis and principal component analysis of faecal microbiota profiles obtained by denaturing gradient gel electrophoresis and quantitative...... PCR, respectively, revealed that the composition of faecal bacteria from UC patients with active disease differed from the healthy controls and that this difference should be ascribed to Gram-negative bacteria. The analysis did not show any clear grouping of UC patients in remission. Even...

  16. DMPD: Gram-negative endotoxin: an extraordinary lipid with profound effects oneukaryotic signal transduction. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 1916089 Gram-negative endotoxin: an extraordinary lipid with profound effects oneuk...ep;5(12):2652-60. (.png) (.svg) (.html) (.csml) Show Gram-negative endotoxin: an extraordinary lipid with profound effects...tive endotoxin: an extraordinary lipid with profound effects oneukaryotic signal transduction. Authors Raetz

  17. [Development and Evaluation of a New Selective Culture Medium, KBM Anaero RS-GNR, for Detection of Anaerobic Gram Negative Rods].

    Science.gov (United States)

    Narita, Taeko; Kato, Kyohei; Hanaiwa, Hiroki; Harada, Tetsuhiro; Funashima, Yumiko; Akiwa, Makoto; Sekiguchi, Jun-Ichiro; Nagasawa, Zenzo; Umemura, Tsukuru

    2017-03-22

    The laboratory culture methods for isolating drug-resistant pathogens has been the gold standard in medical microbiology, and play pivotal roles in the overall management of infectious diseases. Recently, several reports have emphasized the development of antibiotics-resistance among anaerobic gram-negative rods, especially Genus Bacteroides and Prevotella . Therefore, a selective culture method to detect these pathogens is needed. We developed here the new selective culture medium, termed "KBM Anaero RS-GNR," for detecting anaerobic Gram-negative rods. Growth capability and selectivity of the agar medium were assessed by using the pure culture suspensions of more than 100 bacterial strains as well as the 13 samples experimentally contaminated with these bacterial strains. This new medium, "KBM Anaero RS-GNR," successfully showed the selective isolation of anaerobic Gram-negative rods. Compared with commercially available medium, "PV Brucella HK Agar, " which is also designed to detect anaerobic Gram-negative rods, there was no significant difference of the overall detection efficiency between two media. However, "KBM Anaero RS-GNR" showed superior to selectivity for anaerobic Gram-negative rods, especially from the samples contaminated with Candida species. Thus, the culture method using KBM Anaero RS-GNR is relevant for isolation of anaerobic Gram-negative rods especially from clinical specimens.

  18. Higher order structure in the 3'-minor domain of small subunit ribosomal RNAs from a gram negative bacterium, a gram positive bacterium and a eukaryote

    DEFF Research Database (Denmark)

    Douthwaite, S; Christensen, A; Garrett, R A

    1983-01-01

    of additional higher order structure in the renatured free RNA. It can be concluded that a high level of conservation of higher order structure has occurred during the evolution of the gram negative and gram positive eubacteria and the eukaryote in both the double helical regions and the "unstructured" regions...

  19. Gram-Negative Infections in Adult Intensive Care Units of Latin America and the Caribbean

    Directory of Open Access Journals (Sweden)

    Carlos M. Luna

    2014-01-01

    Full Text Available This review summarizes recent epidemiology of Gram-negative infections in selected countries from Latin American and Caribbean adult intensive care units (ICUs. A systematic search of the biomedical literature (PubMed was performed to identify articles published over the last decade. Where appropriate, data also were collected from the reference list of published articles, health departments of specific countries, and registries. Independent cohort data from all countries (Argentina, Brazil, Chile, Colombia, Cuba, Mexico, Trinidad and Tobago, and Venezuela signified a high rate of ICU infections (prevalence: Argentina, 24%; Brazil, 57%. Gram-negative pathogens, predominantly Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Escherichia coli, accounted for >50% of ICU infections, which were often complicated by the presence of multidrug-resistant strains and clonal outbreaks. Empirical use of antimicrobial agents was identified as a strong risk factor for resistance development and excessive mortality. Infection control strategies utilizing hygiene measures and antimicrobial stewardship programs reduced the rate of device-associated infections. To mitigate the poor health outcomes associated with infections by multidrug-resistant Gram-negative bacteria, urgent focus must be placed on infection control strategies and local surveillance programs.

  20. Synergistic antibacterial effect of silver and ebselen against multidrug-resistant Gram-negative bacterial infections.

    Science.gov (United States)

    Zou, Lili; Lu, Jun; Wang, Jun; Ren, Xiaoyuan; Zhang, Lanlan; Gao, Yu; Rottenberg, Martin E; Holmgren, Arne

    2017-08-01

    Multidrug-resistant (MDR) Gram-negative bacteria account for a majority of fatal infections, and development of new antibiotic principles and drugs is therefore of outstanding importance. Here, we report that five most clinically difficult-to-treat MDR Gram-negative bacteria are highly sensitive to a synergistic combination of silver and ebselen. In contrast, silver has no synergistic toxicity with ebselen on mammalian cells. The silver and ebselen combination causes a rapid depletion of glutathione and inhibition of the thioredoxin system in bacteria. Silver ions were identified as strong inhibitors of Escherichia coli thioredoxin and thioredoxin reductase, which are required for ribonucleotide reductase and DNA synthesis and defense against oxidative stress. The bactericidal efficacy of silver and ebselen was further verified in the treatment of mild and acute MDR E. coli peritonitis in mice. These results demonstrate that thiol-dependent redox systems in bacteria can be targeted in the design of new antibacterial drugs. The silver and ebselen combination offers a proof of concept in targeting essential bacterial systems and might be developed for novel efficient treatments against MDR Gram-negative bacterial infections. © 2017 The Authors. Published under the terms of the CC BY 4.0 license.

  1. Mucositis and oral infections secondary to gram negative rods in patients with prolonged neutropenia

    Directory of Open Access Journals (Sweden)

    Mindy M. Sampson

    2017-01-01

    Full Text Available Patients with prolonged neutropenia are at risk for a variety of complications and infections including the development of mucositis and oral ulcers. The changes in oral flora during chemotherapy and its effects on the development of infections of the oral cavity have been studied with inconsistent results. However, there is evidence that supports the colonization of gram negative rods in patients undergoing chemotherapy. In this report, we present two leukemic patients who developed oral ulcers secondary to multi-drug resistant Pseudomonas aeruginosa. It is important to suspect multi-drug resistant gram negative rods in patients with prolonged neutropenia who develop gum infections despite appropriate antibiotic coverage.

  2. Glucocorticosteroids for sepsis

    DEFF Research Database (Denmark)

    Volbeda, M; Wetterslev, J; Gluud, C

    2015-01-01

    INTRODUCTION: Glucocorticosteroids (steroids) are widely used for sepsis patients. However, the potential benefits and harms of both high and low dose steroids remain unclear. A systematic review of randomised clinical trials with meta-analysis and trial sequential analysis (TSA) might shed light...... for sepsis patients (systemic inflammatory response syndrome, sepsis, severe sepsis or septic shock) aged >18 years. Cochrane Central Register of Controlled Trials (CENTRAL), PubMed/Medline, Embase, Web of Science and Cinahl were searched until 18 February 2015. No language restrictions were applied. Primary......-adjusted CI 0.7-1.48). The effects did not vary according to the degree of sepsis. TSA showed that many more randomised patients are needed before definitive conclusions may be drawn. CONCLUSION: Evidence to support or negate the use of steroids in any dose in sepsis patients is lacking. The results...

  3. Bio sorption of some Rare Earth Elements and Yttrium by Gram Positive and Gram Negative Bacteria

    International Nuclear Information System (INIS)

    Ibrahim, H.A.

    2012-01-01

    The separate bio sorption of the REEs La, Sm, Eu and Dy together with yttrium upon the Gram positive bacteria Bacillus subtilis (B.subtilis) and Bacillus Licheniformis (B. Licheniformis),the Gram negative bacterium Escherichia coli (E. coli ) and Saccharomyces cervisiae (Yeast) was studied. The revelant factors of ph 1-6, contact time (30-180 min), the initial rare earth concentration (50-200 mg/l) have been studied. The amount of the accumulated element was strongly affected by its concentration.In addition, bio sorptive fractionation of Y and the studied REEs from a solution containing a mixture of these elements was also studied. From the obtained data, it was found that Langmuir isotherm model for both B.licheniformis and E.coli gives a best fit for the studied elements over the working range of concentration (50-200 mg/I). Transmission electron microscopy exhibited accumulation throughout the bacterial cell with some granular deposits in both the cell periphery and cytoplasm

  4. Experience with polyclonal immunoglobulin therapy in poly trauma patients with severe sepsis

    International Nuclear Information System (INIS)

    Janjua, S.K.; Hussain, R.M.; Mohsin, S.T.; Iqbal, A.; Mishwani, A.H.

    2011-01-01

    To evaluate the effects of intravenous immunoglobulin therapy on progression of severe sepsis in patients of poly trauma. Design: Quasi-experimental study. Place and Duration of Study: Combined Military Hospital Peshawar from June 2008 to Dec 2009. Patients and Methods: Forty six patients of poly trauma with severe sepsis were included. Along with the standard management i.e., surgical management, fluid resuscitation, antibiotics, analgesics, ionotropic, ventilatory and nutritional support, IVIG 5% (intravenous immunoglobulin) was infused over a period of 6 hours and repeated for three consecutive days. Sequential Organ Failure Assessment (SOFA) score was used to assess the progress in all the patients. Results: At the time of enrolment mean SOFA score was 5.41+- 1.127 and on the 15 day it was 1.62 +- 2.24, mean age was 39.21+10.26 years. Thirty four patients (73.91%) developed gram negative sepsis and eighteen patients (39.13%) developed septic shock. Mean duration of stay in ICU and on ventilatory support was 20.80+9.61 and 10.52 + 5.52 days respectively. Thirty five days mortality rate of these patients was 30.43%. Conclusion: The IVIG administration, when used along with the standard management appears to improve significantly the prognosis in patients of poly trauma with severe sepsis. (author)

  5. Probing the Penetration of Antimicrobial Polymyxin Lipopeptides into Gram-Negative Bacteria

    Science.gov (United States)

    2015-01-01

    The dry antibiotic development pipeline coupled with the emergence of multidrug resistant Gram-negative ‘superbugs’ has driven the revival of the polymyxin lipopeptide antibiotics. Polymyxin resistance implies a total lack of antibiotics for the treatment of life-threatening infections. The lack of molecular imaging probes that possess native polymyxin-like antibacterial activity is a barrier to understanding the resistance mechanisms and the development of a new generation of polymyxin lipopeptides. Here we report the regioselective modification of the polymyxin B core scaffold at the N-terminus with the dansyl fluorophore to generate an active probe that mimics polymyxin B pharmacologically. Time-lapse laser scanning confocal microscopy imaging of the penetration of probe (1) into Gram-negative bacterial cells revealed that the probe initially accumulates in the outer membrane and subsequently penetrates into the inner membrane and finally the cytoplasm. The implementation of this polymyxin-mimetic probe will advance the development of platforms for the discovery of novel polymyxin lipopeptides with efficacy against polymyxin-resistant strains. PMID:24635310

  6. Expression levels of matrix metalloproteinase-9 and gram-negative bacteria in symptomatic and asymptomatic periapical lesions.

    Science.gov (United States)

    Ahmed, Geraldine M; El-Baz, Alaa A; Hashem, Ahmed Abdel Rahman; Shalaan, Abeer K

    2013-04-01

    The aim of this study was to test the hypothesis that the expression of matrix metalloproteinase (MMP)-9 is significantly elevated in patients with symptomatic apical periodontitis and to correlate this with the detected amount of gram-negative bacteria. Twenty-six patients with periapical lesions involving at least 2 teeth were included in this study. The patients were divided into 2 groups: the symptomatic (SYM) group included 13 patients expressing pain with periapical lesions, and the asymptomatic (ASYM) group included 13 patients expressing no pain. Root canal treatment was performed followed by endodontic surgery and periapical lesion collection. Periapical lesions were serially cut into 4-μ sections. Some sections were processed for histologic examination using hematoxylin-eosin stain. Other sections were processed for immunohistochemical examination. For MMP-9, the area fraction of the positive cells was measured, and the percentage of the MMP-9-immunopositive area to the total area of the microscopic field was calculated. For gram-negative stain cells, the number of cells showing the pink-red color was counted per microscopic field. The Student's t test was used to compare the SYM and ASYM groups. The Pearson correlation coefficient was used to determine a significant correlation between the number of cells and the MMP-9 level. The significance level was set at P ≤ .05. The SYM group showed a statistically significantly higher mean number of gram-negative cells (P = .001) and MMP-9 area percent (P < .001) than the ASYM group. There was a statistically significant positive (r = .927) correlation between the number of gram-negative cells and the MMP-9 area percent (P< .001). There is good evidence to suspect a significant role of gram-negative bacteria and MMP-9 in symptomatic periapical lesions. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  7. [Left-sided endocarditis due to gram-negative bacilli: epidemiology and clinical characteristics].

    Science.gov (United States)

    Noureddine, Mariam; de la Torre, Javier; Ivanova, Radka; Martínez, Francisco José; Lomas, Jose María; Plata, Antonio; Gálvez, Juan; Reguera, Jose María; Ruiz, Josefa; Hidalgo, Carmen; Luque, Rafael; García-López, María Victoria; de Alarcón, Arístides

    2011-04-01

    The aim of this study is to describe the epidemiological, clinical characteristics, and outcome of patients with left-side endocarditis caused by gram-negative bacteria. Prospective multicenter study of left-sided infective endocarditis reported in the Andalusian Cohort for the Study of Cardiovascular Infections between 1984 and 2008. Among the 961 endocarditis, 24 (2.5%) were caused by gram-negative bacilli. The most common pathogens were Escherichia coli, Pseudomonas aeruginosa and Salmonella enterica. Native valves (85.7%) were mainly affected, most of them with previous valve damage (57%). Comorbidity was greater (90% vs 39%; P=.05) than in endocarditis due to other microorganism, the most frequent being, diabetes, hepatic cirrhosis and neoplasm. A previous manipulation was found in 47.6% of the cases, and 37% were considered hospital-acquired. Renal failure (41%), central nervous system involvement (33%) and ventricular dysfunction (45%) were the most frequent complications. Five cases (21%) required cardiac surgery, mostly due to ventricular dysfunction. More than 50% of cases were treated with aminoglycosides, but this did not lead to a better outcome or prognosis. Mortality (10 patients) was higher than that reported with other microorganisms (41% vs 35%; P=.05). Left-sided endocarditis due to gram-negative bacilli is a rare disease, which affects patients with major morbidities and often with a previous history of hospital manipulations. Cardiac, neurological and renal complications are frequent and associated with a high mortality. The association of aminoglycosides in the antimicrobial treatment did not involve a better outcome or prognosis. Copyright © 2010 Elsevier España, S.L. All rights reserved.

  8. Profil Sepsis Neonatus di Unit Perawatan Neonatus RSUP H Adam Malik Medan Tahun 2008 - 2010

    Directory of Open Access Journals (Sweden)

    Pertin Sianturi

    2016-11-01

    Kesimpulan. Sepsis salah satu penyebab utama kematian neonatus yang dipengaruhi oleh berat lahir rendah, prematuritas, resistensi kuman terhadap antibiotik empirik dan jenis kuman. Penyebab sepsis neonatus terbanyak adalah kuman Gram negatif yang berkontribusi terhadap angka mortalitas

  9. Host defense peptides of thrombin modulate inflammation and coagulation in endotoxin-mediated shock and Pseudomonas aeruginosa sepsis.

    Science.gov (United States)

    Kalle, Martina; Papareddy, Praveen; Kasetty, Gopinath; Mörgelin, Matthias; van der Plas, Mariena J A; Rydengård, Victoria; Malmsten, Martin; Albiger, Barbara; Schmidtchen, Artur

    2012-01-01

    Gram-negative sepsis is accompanied by a disproportionate innate immune response and excessive coagulation mainly induced by endotoxins released from bacteria. Due to rising antibiotic resistance and current lack of other effective treatments there is an urgent need for new therapies. We here present a new treatment concept for sepsis and endotoxin-mediated shock, based on host defense peptides from the C-terminal part of human thrombin, found to have a broad and inhibitory effect on multiple sepsis pathologies. Thus, the peptides abrogate pro-inflammatory cytokine responses to endotoxin in vitro and in vivo. Furthermore, they interfere with coagulation by modulating contact activation and tissue factor-mediated clotting in vitro, leading to normalization of coagulation responses in vivo, a previously unknown function of host defense peptides. In a mouse model of Pseudomonas aeruginosa sepsis, the peptide GKY25, while mediating a modest antimicrobial effect, significantly inhibited the pro-inflammatory response, decreased fibrin deposition and leakage in the lungs, as well as reduced mortality. Taken together, the capacity of such thrombin-derived peptides to simultaneously modulate bacterial levels, pro-inflammatory responses, and coagulation, renders them attractive therapeutic candidates for the treatment of invasive infections and sepsis.

  10. Host defense peptides of thrombin modulate inflammation and coagulation in endotoxin-mediated shock and Pseudomonas aeruginosa sepsis.

    Directory of Open Access Journals (Sweden)

    Martina Kalle

    Full Text Available Gram-negative sepsis is accompanied by a disproportionate innate immune response and excessive coagulation mainly induced by endotoxins released from bacteria. Due to rising antibiotic resistance and current lack of other effective treatments there is an urgent need for new therapies. We here present a new treatment concept for sepsis and endotoxin-mediated shock, based on host defense peptides from the C-terminal part of human thrombin, found to have a broad and inhibitory effect on multiple sepsis pathologies. Thus, the peptides abrogate pro-inflammatory cytokine responses to endotoxin in vitro and in vivo. Furthermore, they interfere with coagulation by modulating contact activation and tissue factor-mediated clotting in vitro, leading to normalization of coagulation responses in vivo, a previously unknown function of host defense peptides. In a mouse model of Pseudomonas aeruginosa sepsis, the peptide GKY25, while mediating a modest antimicrobial effect, significantly inhibited the pro-inflammatory response, decreased fibrin deposition and leakage in the lungs, as well as reduced mortality. Taken together, the capacity of such thrombin-derived peptides to simultaneously modulate bacterial levels, pro-inflammatory responses, and coagulation, renders them attractive therapeutic candidates for the treatment of invasive infections and sepsis.

  11. Nosocomial bloodstream infections in a Turkish university hospital: study of Gram-negative bacilli and their sensitivity patterns.

    Science.gov (United States)

    Köseoğlu , O; Kocagöz, S; Gür, D; Akova, M

    2001-06-01

    Treatment of nosocomial bacteraemia is usually governed by the surveillance results of the particular unit. Such results are especially important when antimicrobial resistance rates are high. Multiresistant isolates including Gram-negatives producing extended-spectrum beta-lactamases have been frequently reported in tertiary care units in Turkey. In this study, antimicrobial susceptibilities of Gram-negative blood isolates (n=348) were determined by microbroth dilution tests. The results showed carbapenems (meropenem and imipenem) to be uniformly more potent in vitro than any other drug against the Enterobacteriaceae. Quinolone antibiotics were more active in vitro than aminoglycosides against a range of bacteria. Gram-negative bloodstream isolates were highly resistant to many antimicrobial agents in the hospital. In order to prevent hospital infection and antimicrobial resistance, surveillance of aetiological agents must be performed regularly.

  12. In-111 WBC imaging in musculoskeletal sepsis

    International Nuclear Information System (INIS)

    Thompson, L.; Ouzounian, T.J.; Webber, M.M.; Amstutz, H.C.

    1984-01-01

    This study evaluated the accuracy and utility of the In-111 labeled WBC imaging in a series of patients who were suspected of having musculoskeletal sepsis. The labeling of the WBCs was patterned after a method previously described, in which the WBCs are labeled with In-111 oxine in plasma. The WBCs from 100 ml of blood are separated and incubated with In-111 oxine complex, and then 500 μCi. of the labeled cells were reinjected into the patient. Images of the areas in question were obtained at 24 hrs. In some instances, 48 hour images were also obtained. Images were interpreted using consistent criteria. Forty imaging procedures were done on 39 patients. These included 39 total joint protheses, and 17 other images to evaluate possible osteomyelitis, septic arthritis or deep abscesses. Of these studies, 15 were positive, and 42 negative. The findings were then correlated with operative culture and pathology in 21, aspiration cultures and gram stains in 14, and with clinical findings in the remaining 21. This correlation showed 41 true negatives, 12 true positives, 1 false negative, and 2 false positives. The sensitivity was 92.9% and the specificity was 95.2%l. The false negative occurred in a patient on chronic suppressive antibiotic therapy for an infected total hip replacement. The false positive images occurred in a patient with active rheumatoid arthritis and in a patient imaged one month post operative placement of the prosthesis. These images were very useful in several septic patients who had many possible sites of infection. The authors conclude that In-III imaging is an accurate and useful non-invasive method of evaluating musculoskeletal sepsis

  13. Melioidosis: the Johor Bahru experience.

    Science.gov (United States)

    Pagalavan, L

    2005-12-01

    A 5 year retrospective review of cases of melioidosis was carried out in Sultanah Aminah Hospital, Johor Bahru. There were 44 new cases of melioidosis which was proven by either blood or pus culture growing Burkholderia pseudomallei from the period between January 1999 and December 2003. Of these, 38 (86.4%) were males compared to only 6 (13.6%) females. Thirty-one (70.5%) were Malays, 7 (15.9%) were Chinese, 5 (11.4%) were Indians and 1 (2.2%) was a Sarawakian. The peak age group was between 50 and 59 years (31.8%). Out of these 44 new cases, only 32 medical records could be retrieved and analysed. Twenty-four out of 32 patients (75%) analysed had diabetes mellitus, 4 had chronic or end stage renal failure (CRF/ESRF) and only 1 had Human Immunodeficiency Virus (HIV). One case of "near drowning" was also recorded. Twenty-one out of 44 patients or 47.7% died, of which 8 (38.1%) died within 24 hours of admission. Pulmonary involvement was recorded in 62.6% of the patients but many had signs and symptoms of multiorgan involvement.

  14. Prevalence and risk factors for CTX-M gram-negative bacteria in hospitalized patients at a tertiary care hospital in Kilimanjaro, Tanzania

    DEFF Research Database (Denmark)

    Sonda, Tolbert; Kumburu, Happiness; van Zwetselaar, Marco

    2018-01-01

    Emergence and spread of extended spectrum beta-lactamase (ESBL)-producing gram-negative bacteria, mainly due to CTX-M, is a major global public health problem. Patients infected with ESBL-producing gram-negative bacteria have an increased risk of treatment failure and death. We investigated...... 2015 were fully genome sequenced. The prevalence of ESBL-producing gram-negative bacteria was determined based on the presence of blaCTX-M. The odds ratio (OR) and risk factors for ESBL-producing gram-negative bacteria due to CTX-M were assessed using logistic regression models. The overall CTX......-M prevalence (95% CI) was 13.6% (10.1–18.1). Adjusted for other factors, the OR of CTX-M gram-negative bacteria for patients previously hospitalized was 0.26 (0.08–0.88), p = 0.031; the OR for patients currently on antibiotics was 4.02 (1.29–12.58), p = 0.017; the OR for patients currently on ceftriaxone was 0...

  15. High resistance rate against 15 different antibiotics in aerobic gram-negative bacteria isolates of cardiology intensive care unit patients

    Directory of Open Access Journals (Sweden)

    Küçükates E

    2002-01-01

    Full Text Available Aerobic gram negative bacteria were isolated and examined microbiologically from various clinical samples of 602 patients hospitalized between January 1997 and December 2000 in surgical and coronary intensive care units (ICUs. A total of 827 isolates were obtained from 602 patients. The majority of microorganisms were isolated from the respiratory tract (50.3% and blood (39.9%. Pseudomonas spp. were the most frequently isolated gram negative species (32.7%, followed by Acinetobacter spp. (24.0% and Klebsiella pneumoniae (19.4%. High resistance rates to all antibiotics studied were observed. Imipenem and meropenem were the most effective antibiotics against gram negatives.

  16. Effect of silver/copper and copper oxide nanoparticle powder on growth of Gram-negative and Gram-positive bacteria and their toxicity against the normal human dermal fibroblasts

    International Nuclear Information System (INIS)

    Peszke, Jerzy; Nowak, Anna; Szade, Jacek; Szurko, Agnieszka; Zygadło, Dorota; Michałowska, Marlena; Krzyściak, Paweł; Zygoń, Patrycja; Ratuszna, Alicja; Ostafin, Marek M.

    2016-01-01

    Engineered nanomaterials, especially metallic nanoparticles, are the most popular system applied in daily life products. The study of their biological and toxicity properties seems to be indispensable. In this paper, we present results of biological activity of Ag/Cu nanoparticles. These nanoparticles show more promising killing/inhibiting properties on Gram-negative bacteria than for Gram-positive ones. The Gram-negative bacteria show strong effect already at the concentration of 1 ppm after 15 min of incubation. Moreover, in vitro tests of toxicity made on normal human dermal fibroblast cultures showed that after 72 h of incubation with Ag/Cu nanoparticles, they are less toxic then Cu 2 O/CuO nanoparticles.

  17. Effect of silver/copper and copper oxide nanoparticle powder on growth of Gram-negative and Gram-positive bacteria and their toxicity against the normal human dermal fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Peszke, Jerzy; Nowak, Anna, E-mail: ana.maria.nowak@gmail.com; Szade, Jacek; Szurko, Agnieszka; Zygadło, Dorota; Michałowska, Marlena [University of Silesia, A. Chelkowski Institute of Physics (Poland); Krzyściak, Paweł [Jagiellonian University Medical College, Department of Mycology Chair of Microbiology (Poland); Zygoń, Patrycja [Czestochowa University of Technology, Institute of Materials Engineering (Poland); Ratuszna, Alicja [University of Silesia, A. Chelkowski Institute of Physics (Poland); Ostafin, Marek M. [Department of Microbiology University of Agriculture (Poland)

    2016-12-15

    Engineered nanomaterials, especially metallic nanoparticles, are the most popular system applied in daily life products. The study of their biological and toxicity properties seems to be indispensable. In this paper, we present results of biological activity of Ag/Cu nanoparticles. These nanoparticles show more promising killing/inhibiting properties on Gram-negative bacteria than for Gram-positive ones. The Gram-negative bacteria show strong effect already at the concentration of 1 ppm after 15 min of incubation. Moreover, in vitro tests of toxicity made on normal human dermal fibroblast cultures showed that after 72 h of incubation with Ag/Cu nanoparticles, they are less toxic then Cu{sub 2}O/CuO nanoparticles.

  18. An unusual class of anthracyclines potentiate Gram-positive antibiotics in intrinsically resistant Gram-negative bacteria

    Science.gov (United States)

    Cox, Georgina; Koteva, Kalinka; Wright, Gerard D.

    2014-01-01

    Objectives An orthogonal approach taken towards novel antibacterial drug discovery involves the identification of small molecules that potentiate or enhance the activity of existing antibacterial agents. This study aimed to identify natural-product rifampicin adjuvants in the intrinsically resistant organism Escherichia coli. Methods E. coli BW25113 was screened against 1120 actinomycete fermentation extracts in the presence of subinhibitory (2 mg/L) concentrations of rifampicin. The active molecule exhibiting the greatest rifampicin potentiation was isolated using activity-guided methods and identified using mass and NMR spectroscopy. Susceptibility testing and biochemical assays were used to determine the mechanism of antibiotic potentiation. Results The anthracycline Antibiotic 301A1 was isolated from the fermentation broth of a strain of Streptomyces (WAC450); the molecule was shown to be highly synergistic with rifampicin (fractional inhibitory concentration index = 0.156) and moderately synergistic with linezolid (FIC index = 0.25) in both E. coli and Acinetobacter baumannii. Activity was associated with inhibition of efflux and the synergistic phenotype was lost when tested against E. coli harbouring mutations within the rpoB gene. Structure–activity relationship studies revealed that other anthracyclines do not synergize with rifampicin and removal of the sugar moiety of Antibiotic 301A1 abolishes activity. Conclusions Screening only a subsection of our natural product library identified a small-molecule antibiotic adjuvant capable of sensitizing Gram-negative bacteria to antibiotics to which they are ordinarily intrinsically resistant. This result demonstrates the great potential of this approach in expanding antibiotic effectiveness in the face of the growing challenge of resistance in Gram-negatives. PMID:24627312

  19. Lipopolysaccharide biogenesis and transport at the outer membrane of Gram-negative bacteria.

    Science.gov (United States)

    Sperandeo, Paola; Martorana, Alessandra M; Polissi, Alessandra

    2017-11-01

    The outer membrane (OM) of Gram-negative bacteria is an asymmetric lipid bilayer containing a unique glycolipid, lipopolysaccharide (LPS) in its outer leaflet. LPS molecules confer to the OM peculiar permeability barrier properties enabling Gram-negative bacteria to exclude many toxic compounds, including clinically useful antibiotics, and to survive harsh environments. Transport of LPS poses several problems to the cells due to the amphipatic nature of this molecule. In this review we summarize the current knowledge on the LPS transport machinery, discuss the challenges associated with this process and present the solutions that bacterial cells have evolved to address the problem of LPS transport and assembly at the cell surface. Finally, we discuss how knowledge on LPS biogenesis can be translated for the development of novel antimicrobial therapies. This article is part of a Special Issue entitled: Bacterial Lipids edited by Russell E. Bishop. Copyright © 2016. Published by Elsevier B.V.

  20. Multiparametric Profiling for Identification of Chemosensitizers against Gram-Negative Bacteria

    Directory of Open Access Journals (Sweden)

    Vincent Lôme

    2018-02-01

    Full Text Available Antibiotic resistance is now a worldwide therapeutic problem. Since the beginning of anti-infectious treatment bacteria have rapidly shown an incredible ability to develop and transfer resistance mechanisms. In the last decades, the design variation of pioneer bioactive molecules has strongly improved their activity and the pharmaceutical companies partly won the race against the clock. Since the 1980s, the new classes of antibiotics that emerged were mainly directed to Gram-positive bacteria. Thus, we are now facing to multidrug-resistant Gram-negative bacteria, with no therapeutic options to deal with them. These bacteria are mainly resistant because of their double membrane that conjointly impairs antibiotic accumulation and extrudes these molecules when entered. The main challenge is to allow antibiotics to cross the impermeable envelope and reach their targets. One promising solution would be to associate, in a combination therapy, a usual antibiotic with a non-antibiotic chemosensitizer. Nevertheless, for effective drug discovery, there is a prominent lack of tools required to understand the rules of permeation and accumulation into Gram-negative bacteria. By the use of a multidrug-resistant enterobacteria, we introduce a high-content screening procedure for chemosensitizers discovery by quantitative assessment of drug accumulation, alteration of barriers, and deduction of their activity profile. We assembled and analyzed a control chemicals library to perform the proof of concept. The analysis was based on real-time monitoring of the efflux alteration and measure of the influx increase in the presence of studied compounds in an automatized bio-assay. Then, synergistic activity of compounds with an antibiotic was studied and kinetic data reduction was performed which led to the calculation of a score for each barrier to be altered.

  1. Emergence of melioidosis in the Indian Ocean region: Two new cases and a literature review.

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    Nicolas Allou

    2017-12-01

    Full Text Available Melioidosis is a disease caused by bacteria called B. pseudomallei. Infections can develop after contact with standing water. This disease can reach all the organs and especially the lungs. It is associated with a high mortality rate (up to 50%. Melioidosis is endemic in northern Australia and in Southeast Asia. Nevertheless, B. pseudomallei may be endemic in the Indian Ocean region and in Madagascar in particular, so clinicians and microbiologists should consider acute melioidosis as a differential diagnosis in the Indian Ocean region, in particular from Madagascar.

  2. Activation of toll-like receptors 2 and 4 by gram-negative periodontal bacteria

    NARCIS (Netherlands)

    Kikkert, R.; Laine, M. L.; Aarden, L. A.; van Winkelhoff, A. J.

    2007-01-01

    BACKGROUND/AIMS: Periodontitis is a chronic infectious disease associated with a gram-negative subgingival microflora. Bacterial components stimulate, among other receptors, Toll-like receptor (TLR) 2 and/or TLR4. Accumulating evidence indicates that both qualitatively and quantitatively distinct

  3. Silver-doped manganese dioxide and trioxide nanoparticles inhibit both gram positive and gram negative pathogenic bacteria.

    Science.gov (United States)

    Kunkalekar, R K; Prabhu, M S; Naik, M M; Salker, A V

    2014-01-01

    Palladium, ruthenium and silver-doped MnO2 and silver doped Mn2O3 nanoparticles were synthesized by simple co-precipitation technique. SEM-TEM analysis revealed the nano-size of these synthesized samples. XPS data illustrates that Mn is present in 4+ and 3+ oxidation states in MnO2 and Mn2O3 respectively. Thermal analysis gave significant evidence for the phase changes with increasing temperature. Antibacterial activity of these synthesized nanoparticles on three Gram positive bacterial cultures (Staphylococcus aureus ATCC 6538, Streptococcus epidermis ATCC 12228, Bacillus subtilis ATCC 6633) and three Gram negative cultures (Escherichia coli ATCC 8739, Salmonella abony NCTC 6017 and Klebsiella pneumoniae ATCC 1003) was investigated using a disc diffusion method and live/dead assay. Only Ag-doped MnO2 and Ag-doped Mn2O3 nanoparticles showed antibacterial property against all six-test bacteria but Ag-doped MnO2 was found to be more effective than Ag-doped Mn2O3. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Nanoparticle targeting of Gram-positive and Gram-negative bacteria for magnetic-based separations of bacterial pathogens

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    Lu, Hoang D.; Yang, Shirley S.; Wilson, Brian K.; McManus, Simon A.; Chen, Christopher V. H.-H.; Prud'homme, Robert K.

    2017-04-01

    Antimicrobial resistance is a healthcare problem of increasing significance, and there is increasing interest in developing new tools to address bacterial infections. Bacteria-targeting nanoparticles hold promise to improve drug efficacy, compliance, and safety. In addition, nanoparticles can also be used for novel applications, such as bacterial imaging or bioseperations. We here present the use of a scalable block-copolymer-directed self-assembly process, Flash NanoPrecipitation, to form zinc(II)-bis(dipicolylamine) modified nanoparticles that bind to both Gram-positive and Gram-negative bacteria with specificity. Particles have tunable surface ligand densities that change particle avidity and binding efficacy. A variety of materials can be encapsulated into the core of the particles, such as optical dyes or iron oxide colloids, to produce imageable and magnetically active bacterial targeting constructs. As a proof-of-concept, these particles are used to bind and separate bacteria from solution in a magnetic column. Magnetic manipulation and separation would translate to a platform for pathogen identification or removal. These magnetic and targeted nanoparticles enable new methods to address bacterial infections.

  5. Phenotypic and functional characterization of human memory T cell responses to Burkholderia pseudomallei.

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    Patcharaporn Tippayawat

    Full Text Available Infection with the Gram-negative bacterium Burkholderia pseudomallei is an important cause of community-acquired lethal sepsis in endemic regions in southeast Asia and northern Australia and is increasingly reported in other tropical areas. In animal models, production of interferon-gamma (IFN-gamma is critical for resistance, but in humans the characteristics of IFN-gamma production and the bacterial antigens that are recognized by the cell-mediated immune response have not been defined.Peripheral blood from 133 healthy individuals who lived in the endemic area and had no history of melioidosis, 60 patients who had recovered from melioidosis, and 31 other patient control subjects were stimulated by whole bacteria or purified bacterial proteins in vitro, and IFN-gamma responses were analyzed by ELISPOT and flow cytometry.B. pseudomallei was a potent activator of human peripheral blood NK cells for innate production of IFN-gamma. In addition, healthy individuals with serological evidence of exposure to B. pseudomallei and patients recovered from active melioidosis developed CD4(+ (and CD8(+ T cells that recognized whole bacteria and purified proteins LolC, OppA, and PotF, members of the B. pseudomallei ABC transporter family. This response was primarily mediated by terminally differentiated T cells of the effector-memory (T(EMRA phenotype and correlated with the titer of anti-B. pseudomallei antibodies in the serum.Individuals living in a melioidosis-endemic region show clear evidence of T cell priming for the ability to make IFN-gamma that correlates with their serological status. The ability to detect T cell responses to defined B. pseudomallei proteins in large numbers of individuals now provides the opportunity to screen candidate antigens for inclusion in protein or polysaccharide-conjugate subunit vaccines against this important but neglected disease.

  6. Melioidosis in Bangladesh: A Clinical and Epidemiological Analysis of Culture-Confirmed Cases

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    Fazle Rabbi Chowdhury

    2018-04-01

    Full Text Available Melioidosis is known to occur in Bangladesh, but there are few reports about the condition in the published international literature. We set out to review all known cases of melioidosis in the country to date, using both retrospective and prospective data. A web-based literature search was conducted to identify all published case reports, original articles and conference abstracts. Cases were also included from a prospective study conducted in 2017. Fifty-one cases were identified between 1961 and 2017. Cases have been reported from sixteen out of the 64 districts of Bangladesh. The median age of the patients at presentation was 45 years (IQR 37–52, with a significant male (77% predominance. Many patients (14/39; 36% were farmers and 83% had diabetes mellitus. A skin/soft tissue abscess was the most common primary clinical presentation (13/49; 27%, followed by septic arthritis (10/49; 20%, pneumonia, and a deep-seated abscess/organ abscess (7/49; 14%. The major challenges to the diagnosis and treatment of melioidosis in Bangladesh are the lack of resources and the lack of awareness of melioidosis. Capacity development programs are urgently required to define the burden of disease and to tackle the mortality rates.

  7. Survival and detection of coliforms, Enterobacteriaceae, and gram-negative bacteria in Greek yogurt.

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    Hervert, C J; Martin, N H; Boor, K J; Wiedmann, M

    2017-02-01

    Despite the widespread use of coliforms as indicator bacteria, increasing evidence suggests that the Enterobacteriaceae (EB) and total gram-negative groups more accurately reflect the hygienic status of high-temperature, short-time pasteurized milk and processing environments. If introduced into milk as postpasteurization contamination, these bacteria may grow to high levels and produce a wide range of sensory-related defects. However, limited information is available on the use and survival of bacterial hygiene indicators in dairy products outside of pasteurized fluid milk and cheese. The goal of this study was to (1) provide information on the survival of a diverse set of bacterial hygiene indicators in the low pH environment of Greek yogurt, (2) compare traditional and alternative detection methods for their ability to detect bacterial hygiene indicators in Greek yogurt, and (3) offer insight into optimal hygiene indicator groups for use in low-pH fermented dairy products. To this end, we screened 64 bacterial isolates, representing 24 dairy-relevant genera, for survival and detection in Greek yogurt using 5 testing methods. Before testing, isolates were inoculated into plain, 0% fat Greek yogurt (pH 4.35 to 4.65), followed by a 12-h hold period at 4 ± 1°C. Yogurts were subsequently tested using Coliform Petrifilm (3M, St. Paul, MN) to detect coliforms; Enterobacteriaceae Petrifilm (3M), violet red bile glucose agar and the D-Count (bioMérieux, Marcy-l'Étoile, France) to detect EB; and crystal violet tetrazolium agar (CVTA) to detect total gram-negative bacteria. Overall, the non-EB gram-negative isolates showed significantly larger log reductions 12 h after inoculation into Greek yogurt (based on bacterial numbers recovered on CVTA) compared with the coliform and noncoliform EB isolates tested. The methods evaluated varied in their ability to detect different microbial hygiene indicators in Greek yogurt. Crystal violet tetrazolium agar detected the highest

  8. O-antigen protects gram-negative bacteria from histone killing.

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    Catherine Chaput

    Full Text Available Beyond their traditional role of wrapping DNA, histones display antibacterial activity to Gram-negative and -positive bacteria. To identify bacterial components that allow survival to a histone challenge, we selected resistant bacteria from homologous Escherichia coli libraries that harbor plasmids carrying pieces of the chromosome in different sizes. We identified genes required for exopolysaccharide production and for the synthesis of the polysaccharide domain of the lipopolysaccharide, called O-antigen. Indeed, O-antigen and exopolysaccharide conferred further resistance to histones. Notably, O-antigen also conferred resistance to histones in the pathogens Shigella flexneri and Klebsiella pneumoniae.

  9. Development of a prototype lateral flow immunoassay (LFI for the rapid diagnosis of melioidosis.

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    Raymond L Houghton

    2014-03-01

    Full Text Available Burkholderia pseudomallei is a soil-dwelling bacterium and the causative agent of melioidosis. Isolation of B. pseudomallei from clinical samples is the "gold standard" for the diagnosis of melioidosis; results can take 3-7 days to produce. Alternatively, antibody-based tests have low specificity due to a high percentage of seropositive individuals in endemic areas. There is a clear need to develop a rapid point-of-care antigen detection assay for the diagnosis of melioidosis. Previously, we employed In vivo Microbial Antigen Discovery (InMAD to identify potential B. pseudomallei diagnostic biomarkers. The B. pseudomallei capsular polysaccharide (CPS and numerous protein antigens were identified as potential candidates. Here, we describe the development of a diagnostic immunoassay based on the detection of CPS. Following production of a CPS-specific monoclonal antibody (mAb, an antigen-capture immunoassay was developed to determine the concentration of CPS within a panel of melioidosis patient serum and urine samples. The same mAb was used to produce a prototype Active Melioidosis Detect Lateral Flow Immunoassay (AMD LFI; the limit of detection of the LFI for CPS is comparable to the antigen-capture immunoassay (∼0.2 ng/ml. The analytical reactivity (inclusivity of the AMD LFI was 98.7% (76/77 when tested against a large panel of B. pseudomallei isolates. Analytical specificity (cross-reactivity testing determined that 97.2% of B. pseudomallei near neighbor species (35/36 were not reactive. The non-reactive B. pseudomallei strain and the reactive near neighbor strain can be explained through genetic sequence analysis. Importantly, we show the AMD LFI is capable of detecting CPS in a variety of patient samples. The LFI is currently being evaluated in Thailand and Australia; the focus is to optimize and validate testing procedures on melioidosis patient samples prior to initiation of a large, multisite pre-clinical evaluation.

  10. Cefepime restriction improves gram-negative overall resistance patterns in neonatal intensive care unit

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    Orlei Ribeiro de Araujo

    Full Text Available Antibiotic restriction can be useful in maintaining bacterial susceptibility. The objective of this study was verify if restriction of cefepime, the most frequently used cephalosporin in our neonatal intensive care unit (NICU, would ameliorate broad-spectrum susceptibility of Gram-negative isolates. Nine hundred and ninety-five premature and term newborns were divided into 3 cohorts, according to the prevalence of cefepime use in the unit: Group 1 (n=396 comprised patients admitted from January 2002 to December 2003, period in which cefepime was the most used broad-spectrum antibiotic. Patients in Group 2 (n=349 were admitted when piperacillin/tazobactam replaced cefepime (January to December 2004 and in Group 3 (n=250 when cefepime was reintroduced (January to September 2005. Meropenem was the alternative third-line antibiotic for all groups. Multiresistance was defined as resistance to 2 or more unrelated antibiotics, including necessarily a third or fourth generation cephalosporin, piperacillin/tazobactam or meropenem. Statistics involved Kruskal-Wallis, Mann-Whitney and logrank tests, Kaplan-Meier analysis. Groups were comparable in length of stay, time of mechanical ventilation, gestational age and birth weight. Ninety-eight Gram-negative isolates were analyzed. Patients were more likely to remain free of multiresistant isolates by Kaplan-Meier analysis in Group 2 when compared to Group 1 (p=0.017 and Group 3 (p=0.003. There was also a significant difference in meropenem resistance rates. Cefepime has a greater propensity to select multiresistant Gram-negative pathogens than piperacillin/tazobactam and should not be used extensively in neonatal intensive care.

  11. A Trojan-Horse Strategy Including a Bacterial Suicide Action for the Efficient Use of a Specific Gram-Positive Antibiotic on Gram-Negative Bacteria.

    Science.gov (United States)

    Schalk, Isabelle J

    2018-05-10

    In the alarming context of rising bacterial antibiotic resistance, there is an urgent need to discover new antibiotics or increase and/or enlarge the activity of those currently in use. The need for new antibiotics is even more urgent in the case of Gram-negative bacteria, such as Acinetobacter, Pseudomonas, and Enterobacteria, which have become resistant to many antibiotics and have an outer membrane with very low permeability to drugs. Vectorization of antibiotics using siderophores may be a solution to bypass such a bacterial wall: the drugs use the iron transporters of the outer membrane as gates to enter bacteria in a Trojan-horse strategy. Designing siderophore-antibiotics that can cross outer membranes has become almost routine, but their transport across the inner membrane is still a limiting step, as well as a strategy that allows dissociation of the antibiotic from the siderophore once inside the bacteria. Liu et al. ( J. Med. Chem. 2018 , DOI: 10.1021/acs.jmedchem.8b00218 ) report the synthesis of a siderophore-cephalosporin compound and demonstrate that β-lactams, such as cephalosporins, can serve as β-lactamase-triggered releasable linkers to allow intracellular delivery of Gram-positive antibiotics to Gram-negative bacteria.

  12. The gram-negative bacterial periplasm: Size matters.

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    Samuel I Miller

    2018-01-01

    Full Text Available Gram-negative bacteria are surrounded by two membrane bilayers separated by a space termed the periplasm. The periplasm is a multipurpose compartment separate from the cytoplasm whose distinct reducing environment allows more efficient and diverse mechanisms of protein oxidation, folding, and quality control. The periplasm also contains structural elements and important environmental sensing modules, and it allows complex nanomachines to span the cell envelope. Recent work indicates that the size or intermembrane distance of the periplasm is controlled by periplasmic lipoproteins that anchor the outer membrane to the periplasmic peptidoglycan polymer. This periplasm intermembrane distance is critical for sensing outer membrane damage and dictates length of the flagellar periplasmic rotor, which controls motility. These exciting results resolve longstanding debates about whether the periplasmic distance has a biological function and raise the possibility that the mechanisms for maintenance of periplasmic size could be exploited for antibiotic development.

  13. Methods for Confirming the Gram Reaction of Gram-variable Bacillus Species Isolated from Tobacco

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    Morin A

    2014-12-01

    Full Text Available Bacillus is a predominant genus of bacteria isolated from tobacco. The Gram stain is the most commonly used and most important of all diagnostic staining techniques in microbiology. In order to help confirm the Gram positivity of Bacillus isolates from tobacco, three methods using the chemical differences of the cell wall and membrane of Gram-positive and Gram-negative bacteria were investigated: the KOH (potassium hydroxide, the LANA (L-alanine-4-nitroanilide, and the vancomycin susceptibility tests. When colonies of Gram-negative bacteria are treated with 3% KOH solution, a slimy suspension is produced, probably due to destruction of the cell wall and liberation of deoxyribonucleic acid (DNA. Gram-positive cell walls resist KOH treatment. The LANA test reveals the presence of a cell wall aminopeptidase that hydrolyzes the L-alanine-4-nitroanilide in Gram-negative bacteria. This enzyme is absent in Gram-positive bacteria. Vancomycin is a glycopeptide antibiotic inhibiting the cell wall peptido-glycan synthesis of Gram-positive microorganisms. Absence of lysis with KOH, absence of hydrolysis of LANA, and susceptibility to vancomycin were used with the Gram reaction to confirm the Gram positivity of various Bacillus species isolated from tobacco. B. laevolacticus excepted, all Bacillus species tested showed negative reactions to KOH and LANA tests, and all species were susceptible to vancomycin (5 and 30 µg.

  14. Pulmonary melioidosis in Cambodia: A prospective study

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    Te Vantha

    2011-05-01

    Full Text Available Abstract Background Melioidosis is a disease caused by Burkholderia pseudomallei and considered endemic in South-East Asia but remains poorly documented in Cambodia. We report the first series of hospitalized pulmonary melioidosis cases identified in Cambodia describing clinical characteristics and outcomes. Methods We characterized cases of acute lower respiratory infections (ALRI that were identified through surveillance in two provincial hospitals. Severity was defined by systolic blood pressure, cardiac frequency, respiratory rate, oxygen saturation and body temperature. B. pseudomallei was detected in sputum or blood cultures and confirmed by API20NE gallery. We followed up these cases between 6 months and 2 years after hospital discharge to assess the cost-of-illness and long-term outcome. Results During April 2007 - January 2010, 39 ALRI cases had melioidosis, of which three aged ≤2 years; the median age was 46 years and 56.4% were males. A close contact with soil and water was identified in 30 patients (76.9%. Pneumonia was the main radiological feature (82.3%. Eleven patients were severe cases. Twenty-four (61.5% patients died including 13 who died within 61 days after discharge. Of the deceased, 23 did not receive any antibiotics effective against B. pseudomallei. Effective drugs that were available did not include ceftazidime. Mean total illness-related costs was of US$65 (range $25-$5000. Almost two-thirds (61.5% incurred debt and 28.2% sold land or other belongings to pay illness-related costs. Conclusions The observed high fatality rate is likely explained by the lack or limited access to efficient antibiotics and under-recognition of the disease among clinicians, which led to inappropriate therapy.

  15. In vitro activity of tigecycline and comparator agents against a global collection of Gram-negative and Gram-positive organisms: tigecycline Evaluation and Surveillance Trial 2004 to 2007.

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    Garrison, Mark W; Mutters, Reinier; Dowzicky, Michael J

    2009-11-01

    The Tigecycline Evaluation and Surveillance Trial began in 2004 to monitor the in vitro activity of tigecycline and comparator agents against a global collection of Gram-negative and Gram-positive pathogens. Against Gram negatives (n = 63 699), tigecycline MIC(90)'s ranged from 0.25 to 2 mg/L for Escherichia coli, Haemophilus influenzae, Acinetobacter baumannii, Klebsiella oxytoca, Enterobacter cloacae, Klebsiella pneumoniae, and Serratia marcescens (but was > or =32 for Pseudomonas aeruginosa). Against Gram-positive organisms (n = 32 218), tigecycline MIC(90)'s were between 0.06 and 0.25 mg/L for Streptococcus pneumoniae, Enterococcus faecium, Streptococcus agalactiae, Staphylococcus aureus, and Enterococcus faecalis. The in vitro activity of tigecycline was maintained against resistant phenotypes, including multidrug-resistant A. baumannii (9.2% of isolates), extended-spectrum beta-lactamase-producing E. coli (7.0%) and K. pneumoniae (14.0%), beta-lactamase-producing H. influenzae (22.2%), methicillin-resistant S. aureus (44.5%), vancomycin-resistant E. faecium (45.9%) and E. faecalis (2.8%), and penicillin-resistant S. pneumoniae (13.8%). Tigecycline represents a welcome addition to the armamentarium against difficult to treat organisms.

  16. Detection of Extended Spectrum Beta-Lactamases Among Gram Negative Bacilli Recovered from Cattle Feces In Benin City, Nigeria

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    Helen Oroboghae OGEFERE

    2017-06-01

    Full Text Available This study was carried out to determine the prevalence of extended spectrum beta-lactamase (ESBL among Gram negative bacteria isolated from cattle feces in Benin City, Nigeria. A total of 250 Gram negative bacteria isolates were recovered from cattle feces and were processed microbiologically using standard techniques. Emergent colonies were identified and antibacterial susceptibility tests were determined using Kirby-Bauer disk diffusion method. All bacterial isolates were screened for the presence of ESBL using the double-disc synergy method. A total of 37 (14.8% isolates were positive for ESBL, with 33 (13.2% indicated by ceftazidime, while only 4 (1.6% were indicated by both ceftazidime and cefotaxime (P < 0.0001. Of the Gram negative bacterial isolates recovered, Salmonella species was the most prevalent ESBL-producer with 55.0% prevalence (P = 0.0092, while no isolate of Pseudomonas aeruginosa produced ESBL. ESBL-positive isolates showed poor susceptibility to the tested antibacterial agents in comparison with non-ESBL-producers and imipenem was the most active antibiotic. The prevalence of ESBL among Gram negative bacilli recovered from cattle feces was 14.8%. The study advises prudent use of antibiotics in the treatment of cattle and harps on improved hygiene in managing cattle, as they are potential reservoirs of ESBL-producing organisms.

  17. Melioidosis Presenting with Isolated Splenic Abscesses: A Case Report

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    Chun-Yu Lin

    2007-08-01

    Full Text Available Splenic abscesses caused by Burkholderia pseudomallei are rarely reported in Taiwan. Here we report a middle-aged man who presented with fever, chills, and general malaise for several days. Abdominal echo revealed isolated splenic abscesses and he received antibiotics treatment according to the initial blood culture result, Serratia marcescens. However, fever did not subside. Then he was referred to our hospital and meropenem was prescribed. Fever subsided 5 days after the beginning of meropenem administration. Repeated fine-needle aspiration of splenic abscesses drained out the pus, which was cultured as B. pseudomallei. He was finally diagnosed as a case of melioidosis based on microbiological evidence. Physicians must take melioidosis into consideration when splenic abscesses are encountered clinically.

  18. An unusual class of anthracyclines potentiate Gram-positive antibiotics in intrinsically resistant Gram-negative bacteria.

    Science.gov (United States)

    Cox, Georgina; Koteva, Kalinka; Wright, Gerard D

    2014-07-01

    An orthogonal approach taken towards novel antibacterial drug discovery involves the identification of small molecules that potentiate or enhance the activity of existing antibacterial agents. This study aimed to identify natural-product rifampicin adjuvants in the intrinsically resistant organism Escherichia coli. E. coli BW25113 was screened against 1120 actinomycete fermentation extracts in the presence of subinhibitory (2 mg/L) concentrations of rifampicin. The active molecule exhibiting the greatest rifampicin potentiation was isolated using activity-guided methods and identified using mass and NMR spectroscopy. Susceptibility testing and biochemical assays were used to determine the mechanism of antibiotic potentiation. The anthracycline Antibiotic 301A(1) was isolated from the fermentation broth of a strain of Streptomyces (WAC450); the molecule was shown to be highly synergistic with rifampicin (fractional inhibitory concentration index = 0.156) and moderately synergistic with linezolid (FIC index = 0.25) in both E. coli and Acinetobacter baumannii. Activity was associated with inhibition of efflux and the synergistic phenotype was lost when tested against E. coli harbouring mutations within the rpoB gene. Structure-activity relationship studies revealed that other anthracyclines do not synergize with rifampicin and removal of the sugar moiety of Antibiotic 301A(1) abolishes activity. Screening only a subsection of our natural product library identified a small-molecule antibiotic adjuvant capable of sensitizing Gram-negative bacteria to antibiotics to which they are ordinarily intrinsically resistant. This result demonstrates the great potential of this approach in expanding antibiotic effectiveness in the face of the growing challenge of resistance in Gram-negatives. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  19. [Analysis of the spectrum and resistance of pathogen causing sepsis in patients with severe acute pancreatitis].

    Science.gov (United States)

    Ma, H X; He, L; Cai, S W; Xin, X L; Shi, H D; Zhou, L; Shi, X J

    2017-05-01

    Objective: To investigate the characteristics of spectrum and drug resistance of pathogens causing sepsis in patients with severe acute pancreatitis(SAP). Methods: The clinical data of 63 SAP patients with sepsis admitted in Department of Hepatobiliary, People's Liberation Army General Hospital from January 2014 to December 2015 were retrospectively studied. There were 47 males and 16 females, aged from 22 to 73 years, with an average age of (52±11)years. Samples were collected mainly from: (1)pancreatic and peripancreatic necrosis and abdominal drainage; (2)bile; (3) blood or deep venous catheter; (4) sputum and tracheal catheter and thoracic drainage; (5) urine. Strain identification and drug-resistance test were preformed on positive specimens. Results: Of 244 pathogenic isolates, mainly derived from abdominal cavity(36.0%), blood stream (14.0%), central venous catheter(11.8%), necrotic tissue(9.1%) and sputum(8.1%); 154(63.1%) were gram-negative bacteria, 68 cases(27.9%) were gram-positive bacteria and 22 cases(9.0%) were fungi respectively. The top six common pathogens isolated were E . coli(16.0%), E .faecium and faecalis(15.2%), P .aeruginosa(10.7%), K .pneumonia(9.8%), Acinetobacter baumanni(8.2%), Stenotrophomonas maltophilia(5.3%)respectively. The detection rate of E . coli and K . pneumonia extended-spectrum β-lactamases(ESBL) was 84.6%(33/39) and 70.8%(17/24), the resistance rate to imipeniem was 12.8% and 25.0%, to cefperazone-sulbactam was 28.2% and 29.2%. As to P . aeruginosa and Acinetobacter bacillus, the resistance rate to imipeniem was 50.0% and 75.0%, to cefperazone-sulbactam was 42.3% and 70.0%; Stenotrophomonas maltophilia was completely resistant to cefperazone-sulbactam, but sensitive to minocycline, SMZ-TMP with the resistance rate less than 40.0%. Gram-positive bacterium strains mainly included E . faecium(38.2%, 26/68), E .faecalis(16.2%, 11/68) and Staphylococcus(35.3%, 24/68) which maintained high sensitivity to vancomycin

  20. Inhibition of various gram-positive and gram-negative bacteria growth on selenium nanoparticle coated paper towels.

    Science.gov (United States)

    Wang, Qi; Larese-Casanova, Philip; Webster, Thomas J

    2015-01-01

    There are wide spread bacterial contamination issues on various paper products, such as paper towels hanging in sink splash zones or those used to clean surfaces, filter papers used in water and air purifying systems, and wrappings used in the food industry; such contamination may lead to the potential spread of bacteria and consequent severe health concerns. In this study, selenium nanoparticles were coated on normal paper towel surfaces through a quick precipitation method, introducing antibacterial properties to the paper towels in a healthy way. Their effectiveness at preventing biofilm formation was tested in bacterial assays involving Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus epidermidis. The results showed significant and continuous bacteria inhibition with about a 90% reduction from 24 to 72 hours for gram-positive bacteria including S. aureus and S. epidermidis. The selenium coated paper towels also showed significant inhibition of gram-negative bacteria like P. aeruginosa and E. coli growth at about 57% and 84%, respectively, after 72 hours of treatment. Therefore, this study established a promising selenium-based antibacterial strategy to prevent bacterial growth on paper products, which may lead to the avoidance of bacteria spreading and consequent severe health concerns.

  1. Differential antibiotic-induced endotoxin release in severe melioidosis

    NARCIS (Netherlands)

    Simpson, A. J.; Opal, S. M.; Angus, B. J.; Prins, J. M.; Palardy, J. E.; Parejo, N. A.; Chaowagul, W.; White, N. J.

    2000-01-01

    Severe melioidosis is a life-threatening, systemic bacterial infection caused by Burkholderia pseudomallei. A prospective, randomized treatment trial was conducted in northeast Thailand to compare ceftazidime (a penicillin-binding protein [PBP]-3-specific agent that causes release of large amounts

  2. Gram-Negative Bacterial Sensors for Eukaryotic Signal Molecules

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    Olivier Lesouhaitier

    2009-09-01

    Full Text Available Ample evidence exists showing that eukaryotic signal molecules synthesized and released by the host can activate the virulence of opportunistic pathogens. The sensitivity of prokaryotes to host signal molecules requires the presence of bacterial sensors. These prokaryotic sensors, or receptors, have a double function: stereospecific recognition in a complex environment and transduction of the message in order to initiate bacterial physiological modifications. As messengers are generally unable to freely cross the bacterial membrane, they require either the presence of sensors anchored in the membrane or transporters allowing direct recognition inside the bacterial cytoplasm. Since the discovery of quorum sensing, it was established that the production of virulence factors by bacteria is tightly growth-phase regulated. It is now obvious that expression of bacterial virulence is also controlled by detection of the eukaryotic messengers released in the micro-environment as endocrine or neuro-endocrine modulators. In the presence of host physiological stress many eukaryotic factors are released and detected by Gram-negative bacteria which in return rapidly adapt their physiology. For instance, Pseudomonas aeruginosa can bind elements of the host immune system such as interferon-γ and dynorphin and then through quorum sensing circuitry enhance its virulence. Escherichia coli sensitivity to the neurohormones of the catecholamines family appears relayed by a recently identified bacterial adrenergic receptor. In the present review, we will describe the mechanisms by which various eukaryotic signal molecules produced by host may activate Gram-negative bacteria virulence. Particular attention will be paid to Pseudomonas, a genus whose representative species, P. aeruginosa, is a common opportunistic pathogen. The discussion will be particularly focused on the pivotal role played by these new types of pathogen sensors from the sensing to the transduction

  3. Transverse myelitis secondary to Melioidosis; A case report

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    Nandasiri Shanika

    2012-09-01

    Full Text Available Abstract Background Melioidosis has become an emerging infection in Sri Lanka; a country which is considered non endemic for it. Paraplegia due to Burkholderia pseudomallei is a very rare entity encountered even in countries where the disease is endemic. There are no reported cases of transverse myelitis due to melioidosis in Sri Lankan population thus we report the first case. Case presentation A 21 year old farmer presented with sudden onset bi lateral lower limb weakness, numbness and urine retention. Examination revealed flaccid areflexic lower limbs with a sensory loss of all modalities and a sensory level at T10 together with sphincter involvement. MRI of the thoracolumbar spine showed extensive myelitis of the thoracic spine complicating left psoas abscess without definite extension to the spinal cord or cord compression. Burkholderia pseudomallei was isolated from the psoas abscess pus cultures and the diagnosis of melioidosis was confirmed with high titers of Burkholderia pseudomallei antibodies and positive PCR. He was treated with high doses of IV ceftazidime and oral cotrimoxazole for one month with a plan to continue cotrimoxazole and doxycycline till one year. Patient’s general condition improved but the residual neurological problems persisted. Conclusion The exact pathogenesis of spinal cord melioidosis is not quite certain except in the cases where there is direct microbial invasion, which does not appear to be the case in our patient. We postulate our patient’s presentation could be due to ischemia of the spinal cord following septic embolisation or thrombosis of spinal artery due to the abscess nearby. A neurotrophic exotoxin causing myelitis or post infectious immunological demyelination is yet another possibility. This emphasizes the necessity of further studies to elucidate the exact pathogenesis in this type of presentations. Health care professionals in Sri Lanka, where this is an emerging infection, need to improve

  4. Imported melioidosis in Danish travellers: a diagnostic challenge

    DEFF Research Database (Denmark)

    Badran, Shadia; Pedersen, Thomas Ingemann; Roed, Casper

    2010-01-01

    Infections with Burkholderia pseudomallei (melioidosis) are rare events in Scandinavian countries, but the bacterium may be contracted during travel to endemic areas, i.e. Southeast Asia (especially Thailand) and northern Australia. Here, 5 travel-related cases occurring within the last 3 y...

  5. A retrospective analysis of melioidosis in Cambodian children, 2009-2013.

    Science.gov (United States)

    Turner, Paul; Kloprogge, Sabine; Miliya, Thyl; Soeng, Sona; Tan, Pisey; Sar, Poda; Yos, Pagnarith; Moore, Catrin E; Wuthiekanun, Vanaporn; Limmathurotsakul, Direk; Turner, Claudia; Day, Nicholas P J; Dance, David A B

    2016-11-21

    Melioidiosis, infection by Burkholderia pseudomallei, is an important but frequently under-recognised cause of morbidity and mortality in Southeast Asia and elsewhere in the tropics. Data on the epidemiology of paediatric melioidosis in Cambodia are extremely limited. Culture-positive melioidosis cases presenting to Angkor Hospital for Children, a non-governmental paediatric hospital located in Siem Reap, Northern Cambodia, between 1 st January 2009 and 31 st December 2013 were identified by searches of hospital and laboratory databases and logbooks. One hundred seventy-three evaluable cases were identified, presenting from eight provinces. For Siem Reap province, the median commune level incidence was estimated to be 28-35 cases per 100,000 children <15 years per year. Most cases presented during the wet season, May to October. The median age at presentation was 5.7 years (range 8 days-15.9 years). Apart from undernutrition, co-morbidities were rare. Three quarters (131/173) of the children had localised infection, most commonly skin/soft tissue infection (60 cases) or suppurative parotitis (51 cases). There were 39 children with B. pseudomallei bacteraemia: 29 (74.4%) of these had clinical and/or radiological evidence of pneumonia. Overall mortality was 16.8% (29/173) with mortality in bacteraemic cases of 71.8% (28/39). At least seven children did not receive an antimicrobial with activity against B. pseudomallei prior to death. This retrospective study demonstrated a considerable burden of melioidosis in Cambodian children. Given the high mortality associated with bacteraemic infection, there is an urgent need for greater awareness amongst healthcare professionals in Cambodia and other countries where melioidosis is known or suspected to be endemic. Empiric treatment guidelines should ensure suspected cases are treated early with appropriate antimicrobials.

  6. Gene expression profiling of Gram-negative bacteria-induced inflammation in human whole blood: The role of complement and CD14-mediated innate immune response

    Directory of Open Access Journals (Sweden)

    Corinna Lau

    2015-09-01

    Full Text Available Non-sterile pathogen-induced sepsis and sterile inflammation like in trauma or ischemia–reperfusion injury may both coincide with the life threatening systemic inflammatory response syndrome and multi-organ failure. Consequently, there is an urgent need for specific biomarkers in order to distinguish sepsis from sterile conditions. The overall aim of this study was to uncover putative sepsis biomarkers and biomarker pathways, as well as to test the efficacy of combined inhibition of innate immunity key players complement and Toll-like receptor co-receptor CD14 as a possible therapeutic regimen for sepsis. We performed whole blood gene expression analyses using microarray in order to profile Gram-negative bacteria-induced inflammatory responses in an ex vivo human whole blood model. The experiments were performed in the presence or absence of inhibitors of complement proteins (C3 and CD88 (C5a receptor 1 and CD14, alone or in combination. In addition, we used blood from a C5-deficient donor. Anti-coagulated whole blood was challenged with heat-inactivated Escherichia coli for 2 h, total RNA was isolated and microarray analyses were performed on the Affymetrix GeneChip Gene 1.0 ST Array platform. The initial experiments were performed in duplicates using blood from two healthy donors. C5-deficiency is very rare, and only one donor could be recruited. In order to increase statistical power, a technical replicate of the C5-deficient samples was run. Subsequently, log2-transformed intensities were processed by robust multichip analysis and filtered using a threshold of four. In total, 73 microarray chips were run and analyzed. The normalized and filtered raw data have been deposited in NCBI's Gene Expression Omnibus (GEO and are accessible with GEO Series accession number GSE55537. Linear models for microarray data were applied to estimate fold changes between data sets and the respective multiple testing adjusted p-values (FDR q-values. The

  7. Antimicrobial Resistance in Gram-Negative Rods Causing Bacteremia in Hematopoietic Stem Cell Transplant Recipients

    DEFF Research Database (Denmark)

    Averbuch, Diana; Tridello, Gloria; Hoek, Jennifer

    2017-01-01

    Background: This intercontinental study aimed to study gram-negative rod (GNR) resistance in hematopoietic stem cell transplantation (HSCT). Methods: GNR bacteremias occurring during 6 months post-HSCT (February 2014-May 2015) were prospectively collected, and analyzed for rates and risk factors...

  8. In vitro Efficacy of Meropenem, Colistin and Tigecycline Against the Extended Spectrum Beta-Lactamase Producing Gram Negative Bacilli

    International Nuclear Information System (INIS)

    Gill, M. M.; Usman, J.; Hassan, A.; Kaleem, F.; Anjum, R.

    2015-01-01

    Objective:To compare the in vitroefficacy of meropenem, colistin and tigecycline against extended spectrum Betalactamase producing Gram negative bacilli by minimal inhibitory concentration. Study Design:Cross-sectional descriptive study. Place and Duration of Study: Department of Microbiology, Army Medical College, National University of Sciences and Technology, Rawalpindi, from June to December 2010. Methodology: Routine clinical specimens were subjected to standard microbiological procedures and the isolates were identified to species level. Extended spectrum beta-lactamase producing Gram negative bacilli were detected by Jarlier disc synergy method and confirmed by ceftazidime and ceftazidime-clavulanate Etest. Minimum Inhibitory Concentration (MIC90) of meropenem, colistin and tigecycline was determined by Etest (AB BIOMERIUX) and the results were interpreted according to the manufacturer's instructions and Clinical and Laboratory Standards Institute guidelines and Food and Drug Authority recommendations. Results were analyzed by using Statistical Package for the Social Sciences version 20. Results: A total of 52 non-duplicate extended spectrum Beta-lactamase-producing Gram negative bacilli were included in the study. The MIC90 of tigecycline (0.75 micro g/ml) was lowest as compared to the meropenem (2 micro g/ml) and colistin (3 micro g/ml). Conclusion: Tigecycline is superior in efficacy against the extended spectrum Beta-lactamase producing Gram negative bacilli as compared to colistin and meropenem. (author)

  9. The Effect of Charge at the Surface of Silver Nanoparticles on Antimicrobial Activity against Gram-Positive and Gram-Negative Bacteria: A Preliminary Study

    International Nuclear Information System (INIS)

    Abbaszadegan, A.; Ghahramani, Y.; Nabavizadeh, M.; Gholami, A.; Hemmateenejad, I.; Dorostkar, S.; Sharghi, H.

    2014-01-01

    The bactericidal efficiency of various positively and negatively charged silver nanoparticles has been extensively evaluated in literature, but there is no report on efficacy of neutrally charged silver nanoparticles. The goal of this study is to evaluate the role of electrical charge at the surface of silver nanoparticles on antibacterial activity against a panel of microorganisms. Three different silver nanoparticles were synthesized by different methods, providing three different electrical surface charges (positive, neutral, and negative). The antibacterial activity of these nanoparticles was tested against gram-positive (i.e., Staphylococcus aureus, Streptococcus mutans, and Streptococcus pyogenes) and gram-negative (i.e., Escherichia coli and Proteus vulgaris) bacteria. Well diffusion and micro-dilution tests were used to evaluate the bactericidal activity of the nanoparticles. According to the obtained results, the positively-charged silver nanoparticles showed the highest bactericidal activity against all microorganisms tested. The negatively charged silver nanoparticles had the least and the neutral nanoparticles had intermediate antibacterial activity. The most resistant bacteria were Proteus vulgaris. We found that the surface charge of the silver nanoparticles was a significant factor affecting bactericidal activity on these surfaces. Although the positively charged nanoparticles showed the highest level of effectiveness against the organisms tested, the neutrally charged particles were also potent against most bacterial species.

  10. Antibacterial activity of sphingoid bases and fatty acids against Gram-positive and Gram-negative bacteria.

    Science.gov (United States)

    Fischer, Carol L; Drake, David R; Dawson, Deborah V; Blanchette, Derek R; Brogden, Kim A; Wertz, Philip W

    2012-03-01

    There is growing evidence that the role of lipids in innate immunity is more important than previously realized. How lipids interact with bacteria to achieve a level of protection, however, is still poorly understood. To begin to address the mechanisms of antibacterial activity, we determined MICs and minimum bactericidal concentrations (MBCs) of lipids common to the skin and oral cavity--the sphingoid bases D-sphingosine, phytosphingosine, and dihydrosphingosine and the fatty acids sapienic acid and lauric acid--against four Gram-negative bacteria and seven Gram-positive bacteria. Exact Kruskal-Wallis tests of these values showed differences among lipid treatments (P 500 μg/ml). Sapienic acid (MBC range, 31.3 to 375.0 μg/ml) was active against Streptococcus sanguinis, Streptococcus mitis, and Fusobacterium nucleatum but not active against Escherichia coli, Staphylococcus aureus, S. marcescens, P. aeruginosa, Corynebacterium bovis, Corynebacterium striatum, and Corynebacterium jeikeium (MBC > 500 μg/ml). Lauric acid (MBC range, 6.8 to 375.0 μg/ml) was active against all bacteria except E. coli, S. marcescens, and P. aeruginosa (MBC > 500 μg/ml). Complete killing was achieved as early as 0.5 h for some lipids but took as long as 24 h for others. Hence, sphingoid bases and fatty acids have different antibacterial activities and may have potential for prophylactic or therapeutic intervention in infection.

  11. Risk score for identifying adults with CSF pleocytosis and negative CSF Gram stain at low risk for an urgent treatable cause

    NARCIS (Netherlands)

    Hasbun, Rodrigo; Bijlsma, Merijn; Brouwer, Matthijs C.; Khoury, Nabil; Hadi, Christiane M.; van der Ende, Arie; Wootton, Susan H.; Salazar, Lucrecia; Hossain, Md Monir; Beilke, Mark; van de Beek, Diederik

    2013-01-01

    We aimed to derive and validate a risk score that identifies adults with cerebrospinal fluid (CSF) pleocytosis and a negative CSF Gram stain at low risk for an urgent treatable cause. Patients with CSF pleocytosis and a negative CSF Gram stain were stratified into a prospective derivation (n = 193)

  12. Relative uptake of technetium 99m stannous colloid by neutrophils and monocytes is altered by gram-negative infection

    International Nuclear Information System (INIS)

    Ramsay, Stuart C.; Maggs, Jacqueline A.; Ketheesan, Natkunam; Norton, Robert; LaBrooy, Justin

    2005-01-01

    Gram-negative infection alters phagocytic cell function; hence, it could affect phagocytic uptake of inorganic colloids by these cells. Neutrophil and monocyte uptake of technetium 99m stannous colloid ( 99m Tc SnC) in whole blood was measured in 10 patients with gram-negative infection (Burkholderia pseudomallei) and 7 controls. Mean uptake per individual neutrophil was reduced in infection. Uptake per monocyte was not significantly different. Blood from six normal individuals was incubated with lysed B. pseudomallei and colloid, which showed reduced neutrophil uptake, but increased monocyte uptake. These results indicate that uptake of 99m Tc SnC stannous colloid can be used to measure alteration in phagocytic cell function. They suggest that infection with B. pseudomallei is associated with reduced phagocytosis by individual neutrophils, possibly through toxic effects of bacterial products. This could have immunopathogenic consequences for this gram-negative infection and may explain why it responds to granulocyte colony-stimulating factor

  13. Melioidosis of Chest Wall Masquerading as a Tubercular Cold ...

    African Journals Online (AJOL)

    chest wall abscess mimicking tuberculous cold abscess for its rarity and to review the ... was suspected to have pulmonary tuberculosis by a private practitioner and was ... Risk factors for melioidosis include diabetes mellitus, excessive alcohol ...

  14. A study of gram-negative bacterial resistance to Aminoglycosides

    Directory of Open Access Journals (Sweden)

    Maleknejad P

    1993-05-01

    Full Text Available From hygienic and economical point of view, drug therapy and prophylaxy in infectious diseases are of great importance. After the world war II, a reduction in the efficacy of sulfonamide in the treatment of shigellosis was observed and later on it led to a survey on drug resistance and the way of its transmission. The aim of this survey, during which 100 cases of gram-negative bacteria were identified, is to study the drug resistance of this bacteria against five types of aminoglycosides by antibiotic sensitivity test (disc-diffusion. Out of 100 strains, 47% were resistant to gentamycin, 70% to kanamycin, 82% to streptomycin, 53% to tobramycin, and 8% to amikacin

  15. DMPD: Lipopolysaccharide sensing an important factor in the innate immune response toGram-negative bacterial infections: benefits and hazards of LPShypersensitivity. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available se toGram-negative bacterial infections: benefits and hazards of LPShypersensitivity. Freudenberg MA, Tchapt...portant factor in the innate immune response toGram-negative bacterial infections: benefits and hazards of L...une response toGram-negative bacterial infections: benefits and hazards of LPShyp

  16. Melioidosis in Myanmar

    Directory of Open Access Journals (Sweden)

    Mo Mo Win

    2018-03-01

    Full Text Available Sporadic cases of melioidosis have been diagnosed in Myanmar since the disease was first described in Yangon in 1911. Published and unpublished cases are summarized here, along with results from environmental and serosurveys. A total of 298 cases have been reported from seven states or regions between 1911 and 2018, with the majority of these occurring before 1949. Findings from soil surveys confirm the presence of Burkholderia pseudomallei in the environment in all three regions examined. The true epidemiology of the disease in Myanmar is unknown. Important factors contributing to the current gaps in knowledge are lack of awareness among clinicians and insufficient laboratory diagnostic capacity in many parts of the country. This is likely to have led to substantial under-reporting.

  17. Imported melioidosis in Japan: a review of cases.

    Science.gov (United States)

    Hadano, Yoshiro

    2018-01-01

    Fourteen cases of reported melioidosis in Japan were reviewed. The mean age was 52.4 years (33-69 years), and all patients were male. All of the presumed exposures originated in Southeast Asia. The most common underlying disease was diabetes mellitus, including those patients with impaired glucose tolerance (n=8). As for mode of onset, 13 patients had acute infections and one had chronic infection. Of these 14 patients, the most common infection site on admission was lung (n=8), followed by bone (n=5), skin (n=4), gastrointestinal abscess formation (n=3), urinary tract (n=3), aorta (n=2), mediastinal lymph node swelling (n=1), and central nervous system (n=1). Bacteremia was observed in nine patients, and Burkholderia pseudomallei isolates were mostly susceptible to ceftazidime and carbapenem. Overall mortality was 14.3%. Melioidosis is a rare infection in Japan, with all known cases to date having been imported from Southeast Asia. Diabetes was a common risk factor.

  18. Sinus surgery postpones chronic Gram-negative lung infection

    DEFF Research Database (Denmark)

    Alanin, M C; Aanaes, K; Høiby, N

    2016-01-01

    of pulmonary samples positive for GNB. We investigated whether the effect is sustained. METHODOLOGY: We report the effect of ESS and adjuvant therapy three years postoperatively in a CF cohort participating in this prospective clinical follow-up study. The primary endpoint was the lung infection status defined......BACKGROUND: In patients with cystic fibrosis (CF) the sinuses are a bacterial reservoir for Gram-negative bacteria (GNB). From the sinuses the GNB can repeatedly migrate to the lungs. In a one-year follow-up study, endoscopic sinus surgery (ESS) with adjuvant therapy reduced the frequency....... The total cohort had decreasing lung function during follow-up; however, in 27 patients with improved lung infection status lung function was stable. Revision surgery was performed in 31 patients (28%). CONCLUSION: ESS with adjuvant therapy significantly improves the lung infection status for at least three...

  19. Optimizing empiric therapy for Gram-negative bloodstream infections in children.

    Science.gov (United States)

    Chao, Y; Reuter, C; Kociolek, L K; Patel, R; Zheng, X; Patel, S J

    2018-06-01

    Antimicrobial stewardship can be challenging in children with bloodstream infections (BSIs) caused by Gram-negative bacilli (GNB). This retrospective cohort study explored how data elements in the electronic health record could potentially optimize empiric antibiotic therapy for BSIs caused by GNB, via the construction of customized antibiograms for categorical GNB infections and identification of opportunities to minimize organism-drug mismatch and decrease time to effective therapy. Our results suggest potential strategies that could be implemented at key decision points in prescribing at initiation, modification, and targeting of therapy. Copyright © 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  20. Imaging and clinical analysis of 12 cases with melioidosis

    International Nuclear Information System (INIS)

    Yu Anle; Chen Hai; Li Qun

    2007-01-01

    Objective: Imaging and clinical manifestations of melioidosis were analyzed in order to improve our understanding of the disease and to reduce the rate of misdiagnosis. Methods: From 2001 to 2006, 12 melioidosis cases were confirmed by blood, pus and sputum culture. All cases were examined with radiography, and nine of them with CT and 2 with US. The imaging and clinical data were assessed retrospectively. Results: Ten of 12 cases revealed lung abnormalities, the main organ involved by melioidosis in the body. The appearances were observed as follows: diffused sheets and sheets fused partly in bilateral fields of the lungs can be seen on chest radiograph; homogeneous dense shadow of the lobe or segment were observed on plain chest film and CT; blurred strips radiated from hilum were revealed on plain chest film; multitude nodules in 2 lungs showed on CT; cavity with air and liquid be seen on plain chest film and CT; patches and granules in superior and middle fields or (and) inferior fields be seen on plain chest film and CT; arc shadow of water attenuation in dorsal thorax showed on CT. Infections outside the lung can be observed in orbital, lumbar muscle, liver and spleen in 1 case, and thighbone osteomyelitis with multi abscesses in one case. Conclusion: Alhough medioidosis has no characteristic imaging appearances, the disease's location, extent, severity and quantity objectively can be demonstrated by imaging, final confirmation is necessary using the culture of blood, pus and sputum. (authors)

  1. Emerging Gram negative resistance to last-line antimicrobial agents fosfomycin, colistin and ceftazidime-avibactam - epidemiology, laboratory detection and treatment implications.

    Science.gov (United States)

    Sherry, Norelle; Howden, Benjamin

    2018-04-01

    Multidrug-resistant (MDR) and extensively-drug-resistant (XDR) Gram-negative bacteria have emerged as a major threat to human health globally. This has resulted in the 're-discovery' of some older antimicrobials and development of new agents, however resistance has also rapidly emerged to these agents. Areas covered: Here we describe recent developments in resistance to three of the most important last-line antimicrobials for treatment of MDR and XDR Gram negatives: fosfomycin, colistin and ceftazidime-avibactam. Expert commentary: A key challenge for microbiologists and clinicians using these agents for treating patients with MDR and XDR Gram negative infections is the need to ensure appropriate reference methods are being used to test susceptibility to these agents, especially colistin and fosfomycin. These methods are not available in all laboratories meaning accurate results are either delayed, or potentially inaccurate as non-reference methods are employed. Combination therapy for MDR and XDR Gram negatives is likely to become more common, and future studies should focus on the clinical effects of monotherapy vs combination therapy, as well as validation of synergy testing methods. Effective national and international surveillance systems to detect and respond to resistance to these last line agents are also critical.

  2. Common TNF-alpha, IL-1 beta, PAI-1, uPA, CD14 and TLR4 polymorphisms are not associated with disease severity or outcome from Gram negative sepsis

    DEFF Research Database (Denmark)

    Jessen, Kristine Marie; Lindboe, Sarah Bjerre; Petersen, Anncatrine Luisa

    2007-01-01

    Several studies have investigated single nucleotide polymorphisms (SNPs) in candidate genes associated with sepsis and septic shock with conflicting results. Only few studies have combined the analysis of multiple SNPs in the same population.......Several studies have investigated single nucleotide polymorphisms (SNPs) in candidate genes associated with sepsis and septic shock with conflicting results. Only few studies have combined the analysis of multiple SNPs in the same population....

  3. Septicemia caused by the gram-negative bacterium CDC IV c-2 in an immunocompromised human.

    OpenAIRE

    Dan, M; Berger, S A; Aderka, D; Levo, Y

    1986-01-01

    A 37-year-old man with plasma cell leukemia developed nonfatal septicemia caused by the gram-negative bacterium CDC IV c-2. Recovery followed appropriate treatment with antibiotics. The biochemical features of this organism are reviewed.

  4. Gram staining for the treatment of peritonsillar abscess.

    Science.gov (United States)

    Takenaka, Yukinori; Takeda, Kazuya; Yoshii, Tadashi; Hashimoto, Michiko; Inohara, Hidenori

    2012-01-01

    Objective. To examine whether Gram staining can influence the choice of antibiotic for the treatment of peritonsillar abscess. Methods. Between 2005 and 2009, a total of 57 cases of peritonsillar abscess were analyzed with regard to cultured bacteria and Gram staining. Results. Only aerobes were cultured in 16% of cases, and only anaerobes were cultured in 51% of cases. Mixed growth of aerobes and anaerobes was observed in 21% of cases. The cultured bacteria were mainly aerobic Streptococcus, anaerobic Gram-positive cocci, and anaerobic Gram-negative rods. Phagocytosis of bacteria on Gram staining was observed in 9 cases. The bacteria cultured from these cases were aerobic Streptococcus, anaerobic Gram-positive cocci, and anaerobic Gram-negative rods. The sensitivity of Gram staining for the Gram-positive cocci and Gram-negative rods was 90% and 64%, respectively. The specificity of Gram staining for the Gram-positive cocci and Gram-negative rods was 62% and 76%, respectively. Most of the Gram-positive cocci were sensitive to penicillin, but some of anaerobic Gram-negative rods were resistant to penicillin. Conclusion. When Gram staining shows only Gram-positive cocci, penicillin is the treatment of choice. In other cases, antibiotics effective for the penicillin-resistant organisms should be used.

  5. Differential staining of bacteria: gram stain.

    Science.gov (United States)

    Moyes, Rita B; Reynolds, Jackie; Breakwell, Donald P

    2009-11-01

    In 1884, Hans Christian Gram, a Danish doctor, developed a differential staining technique that is still the cornerstone of bacterial identification and taxonomic division. This multistep, sequential staining protocol separates bacteria into four groups based on cell morphology and cell wall structure: Gram-positive cocci, Gram-negative cocci, Gram-positive rods, and Gram-negative rods. The Gram stain is useful for assessing bacterial contamination of tissue culture samples or for examining the Gram stain status and morphological features of bacteria isolated from mixed or isolated bacterial cultures. (c) 2009 by John Wiley & Sons, Inc.

  6. Evaluation of musculoskeletal sepsis with indium-111 white blood cell imaging

    International Nuclear Information System (INIS)

    Ouzounian, T.J.; Thompson, L.; Grogan, T.J.; Webber, M.M.; Amstutz, H.C.

    1987-01-01

    The detection of musculoskeletal sepsis, especially following joint replacement, continues to be a challenging problem. Often, even with invasive diagnostic evaluation, the diagnosis of infection remains uncertain. This is a report on the first 55 Indium-111 white blood cell (WBC) images performed in 39 patients for the evaluation of musculoskeletal sepsis. There were 40 negative and 15 positive Indium-111 WBC images. These were correlated with operative culture and tissue pathology, aspiration culture, and clinical findings. Thirty-eight images were performed for the evaluation of possible total joint sepsis (8 positive and 30 negative images); 17 for the evaluation of nonarthroplasty-related musculoskeletal sepsis (7 positive and 10 negative images). Overall, there were 13 true-positive, 39 true-negative, two false-positive, and one false-negative images. Indium-111 WBC imaging is a sensitive and specific means of evaluating musculoskeletal sepsis, especially following total joint replacement

  7. Distinction of Gram-positive and -negative bacteria using a colorimetric microbial viability assay based on the reduction of water-soluble tetrazolium salts with a selection medium.

    Science.gov (United States)

    Tsukatani, Tadayuki; Suenaga, Hikaru; Higuchi, Tomoko; Shiga, Masanobu; Noguchi, Katsuya; Matsumoto, Kiyoshi

    2011-01-01

    Bacteria are fundamentally divided into two groups: Gram-positive and Gram-negative. Although the Gram stain and other techniques can be used to differentiate these groups, some issues exist with traditional approaches. In this study, we developed a method for differentiating Gram-positive and -negative bacteria using a colorimetric microbial viability assay based on the reduction of the tetrazolium salt {2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodium salt} (WST-8) via 2-methyl-1,4-napthoquinone with a selection medium. We optimized the composition of the selection medium to allow the growth of Gram-negative bacteria while inhibiting the growth of Gram-positive bacteria. When the colorimetric viability assay was carried out in a selection medium containing 0.5µg/ml crystal violet, 5.0 µg/ml daptomycin, and 5.0µg/ml vancomycin, the reduction in WST-8 by Gram-positive bacteria was inhibited. On the other hand, Gram-negative bacteria produced WST-8-formazan in the selection medium. The proposed method was also applied to determine the Gram staining characteristics of bacteria isolated from various foodstuffs. There was good agreement between the results obtained using the present method and those obtained using a conventional staining method. These results suggest that the WST-8 colorimetric assay with selection medium is a useful technique for accurately differentiating Gram-positive and -negative bacteria.

  8. Exploring the hidden potential of fosfomycin for the fight against severe Gram-negative infections

    Directory of Open Access Journals (Sweden)

    P V Saiprasad

    2016-01-01

    Full Text Available Gram-negative resistance is a serious global crisis putting the world on the cusp of 'pre-antibiotic era'. This serious crisis has been catalysed by the rapid increase in carbapenem-resistant Enterobacteriaceae (CRE. Spurge in colistin usage to combat CRE infections leads to the reports of (colistin and carbapenem resistant enterobacteriaceae CCRE (resistance to colistin in isolates of CRE infections further jeopardising our last defence. The antibacterial apocalypse imposed by global resistance crisis requires urgent alternative therapeutic options. Interest in the use of fosfomycin renewed recently for serious systemic infections caused by multidrug-resistant Enterobacteriaceae. This review aimed at analysing the recent evidence on intravenous fosfomycin to explore its hidden potential, especially when fosfomycin disodium is going to be available in India. Although a number of promising evidence are coming up for fosfomycin, there are still areas where more work is required to establish intravenous fosfomycin as the last resort antibacterial for severe Gram-negative infections.

  9. Low antibiotic resistance among anaerobic Gram-negative bacteria in periodontitis 5 years following metronidazole therapy.

    Science.gov (United States)

    Dahlen, G; Preus, H R

    2017-02-01

    The objective of this study was to assess antibiotic susceptibility among predominant Gram-negative anaerobic bacteria isolated from periodontitis patients who 5 years prior had been subject to mechanical therapy with or without adjunctive metronidazole. One pooled sample was taken from the 5 deepest sites of each of 161 patients that completed the 5 year follow-up after therapy. The samples were analyzed by culture. A total number of 85 anaerobic strains were isolated from the predominant subgingival flora of 65/161 patient samples, identified, and tested for antibiotic susceptibility by MIC determination. E-tests against metronidazole, penicillin, amoxicillin, amoxicillin + clavulanic acid and clindamycin were employed. The 73/85 strains were Gram-negative rods (21 Porphyromonas spp., 22 Prevotella/Bacteroides spp., 23 Fusobacterium/Filifactor spp., 3 Campylobacter spp. and 4 Tannerella forsythia). These were all isolated from the treated patients irrespective of therapy procedures (+/-metronidazole) 5 years prior. Three strains (Bifidobacterium spp., Propionibacterium propionicum, Parvimonas micra) showed MIC values for metronidazole over the European Committee on Antimicrobial Susceptibility Testing break point of >4 μg/mL. All Porphyromonas and Tannerella strains were highly susceptible. Metronidazole resistant Gram-negative strains were not found, while a few showed resistance against beta-lactam antibiotics. In this population of 161 patients who had been subject to mechanical periodontal therapy with or without adjunct metronidazole 5 years prior, no cultivable antibiotic resistant anaerobes were found in the predominant subgingival microbiota. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. The comparison of pyrosequencing molecular Gram stain, culture, and conventional Gram stain for diagnosing orthopaedic infections.

    Science.gov (United States)

    Kobayashi, Naomi; Bauer, Thomas W; Tuohy, Marion J; Lieberman, Isador H; Krebs, Viktor; Togawa, Daisuke; Fujishiro, Takaaki; Procop, Gary W

    2006-08-01

    We have developed a combined real-time PCR and pyrosequencing assay that successfully differentiated the vast majority of gram-positive and gram-negative bacteria when bacterial isolates were tested. The purpose of this study was to evaluate this assay on clinical specimens obtained from orthopedic surgeries, and to prospectively compare the results of "molecular Gram stain" with culture and conventional direct Gram stain. Forty-five surgical specimens were obtained from patients who underwent orthopedic surgery procedures. The DNA was extracted and a set of broad-range PCR primers that targeted a part of the 16S rDNA gene was used for pan-bacterial PCR. The amplicons were submitted for pyrosequencing and the resulting molecular Gram stain characteristics were recorded. Culture and direct Gram staining were performed using standard methods for all cases. Surgical specimens were reviewed histologically for all cases that had a discrepancy between culture and molecular results. There was an 86.7% (39/45) agreement between the traditional and molecular methods. In 12/14 (85.7%) culture-proven cases of bacterial infection, molecular Gram stain characteristics were in agreement with the culture results, while the conventional Gram stain result was in agreement only for five cases (35.7%). In the 31 culture negative cases, 27 cases were also PCR negative, whereas 4 were PCR positive. Three of these were characterized as gram negative and one as gram positive by this molecular method. Molecular determination of the Gram stain characteristics of bacteria that cause orthopedic infections may be achieved, in most instances, by this method. Further studies are necessary to understand the clinical importance of PCR-positive/culture-negative results.

  11. Frequency and Treatment of Methicillin Resistant Staphylococcus aureus in Obstetric and Gynaecological Sepsis

    International Nuclear Information System (INIS)

    Butt, I.J.; Khan, S.; Bhutta, S.; Butt, S.

    2013-01-01

    Objective: To perform culture and sensitivity for pathogens causing puerperal and postoperative wound sepsis and determine the frequency of Methicillin Resistant Staphylococcus aureus (MRSA) in such infections. Study Design: Observational study. Place and Duration of Study: Obstetrics and Gynaecology Ward, Jinnah Postgraduate Medical Centre, Karachi, from December 2008 to May 2010. Methodology: All patients presenting with puerperal sepsis or postoperative wound infection were enrolled. Pus was collected for culture and sensitivity using standard technique. Two samples were taken from each patient; one before starting the treatment and one at the end of treatment. Ames transport medium was used. Empirical treatment with triple regimen (Ampicillin, Metronidazole and Gentamicin) was started immediately to cover Gram positive as well as negative bacteria in addition to anaerobic infection. After receiving the sensitivity report, antimicrobial agent were changed accordingly. Samples from ward and theater staff and environment were also taken to look for possible mode of transmission. Data was recorded on a proforma. Discrete variables are expressed as percentages. Results: Staphylococcus aureus was the most frequent organism isolated in 34.6% cases. Methicillin sensitive Staphylococcus aureus was seen in 20% cases and methicillin resistant Staphylococcus aureus was seen in 14.6%. Out of these 14.6% MRSA, (17) 77% was associated with puerperal sepsis and rest (5) 23% was associated with postoperative wound infection. It showed best sensitivity to vancomycin. Conclusion: Staphylococcus aureus and E. coli were common causative agent of postoperative infections and puerperal sepsis. (author)

  12. Comparison of the lysis centrifugation method with the conventional blood culture method in cases of sepsis in a tertiary care hospital.

    Science.gov (United States)

    Parikh, Harshal R; De, Anuradha S; Baveja, Sujata M

    2012-07-01

    Physicians and microbiologists have long recognized that the presence of living microorganisms in the blood of a patient carries with it considerable morbidity and mortality. Hence, blood cultures have become critically important and frequently performed test in clinical microbiology laboratories for diagnosis of sepsis. To compare the conventional blood culture method with the lysis centrifugation method in cases of sepsis. Two hundred nonduplicate blood cultures from cases of sepsis were analyzed using two blood culture methods concurrently for recovery of bacteria from patients diagnosed clinically with sepsis - the conventional blood culture method using trypticase soy broth and the lysis centrifugation method using saponin by centrifuging at 3000 g for 30 minutes. Overall bacteria recovered from 200 blood cultures were 17.5%. The conventional blood culture method had a higher yield of organisms, especially Gram positive cocci. The lysis centrifugation method was comparable with the former method with respect to Gram negative bacilli. The sensitivity of lysis centrifugation method in comparison to conventional blood culture method was 49.75% in this study, specificity was 98.21% and diagnostic accuracy was 89.5%. In almost every instance, the time required for detection of the growth was earlier by lysis centrifugation method, which was statistically significant. Contamination by lysis centrifugation was minimal, while that by conventional method was high. Time to growth by the lysis centrifugation method was highly significant (P value 0.000) as compared to time to growth by the conventional blood culture method. For the diagnosis of sepsis, combination of the lysis centrifugation method and the conventional blood culture method with trypticase soy broth or biphasic media is advocable, in order to achieve faster recovery and a better yield of microorganisms.

  13. Beta-lactam resistance in the gram negatives: increasing complexity of conditional, composite and multiply resistant phenotypes.

    Science.gov (United States)

    Iredell, Jon; Thomas, Lee; Espedido, Björn

    2006-12-01

    The greatest impact of microbiology data on clinical care is in the critically ill. Unfortunately, this is also the area in which microbiology laboratories are most often non-contributive. Attempts to move to rapid, culture-independent diagnostics are driven by the need to expedite urgent results. This is difficult in Gram-negative infection because of the complexity of the antibiotic resistance phenotype. Here, we discuss resistance to modern beta-lactams as a case in point. Recent outbreaks of transmissible carbapenem resistance among Gram-negative enteric pathogens in Sydney and Melbourne serve to illustrate the pitfalls of traditional phenotypical approaches. A better understanding of the epidemiology and mosaic nature of antibiotic resistance elements in the microflora is needed for us to move forward.

  14. MALDI-TOF MS contribution to diagnosis of melioidosis in a nonendemic country in three French travellers

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    V. Walewski

    2016-07-01

    Full Text Available Melioidosis is an endemic disease in Southeast Asia and northern Australia. An increasing number of cases are being reported in nonendemic countries, making the diagnosis less obvious. We discuss the identification of Burkholderia pseudomallei using matrix-assisted desorption ionization–time of flight mass spectrometry on the occasion of recent cases of imported melioidosis in French travellers.

  15. A retrospective analysis of melioidosis in Cambodian children, 2009–2013

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    Paul Turner

    2016-11-01

    Full Text Available Abstract Background Melioidiosis, infection by Burkholderia pseudomallei, is an important but frequently under-recognised cause of morbidity and mortality in Southeast Asia and elsewhere in the tropics. Data on the epidemiology of paediatric melioidosis in Cambodia are extremely limited. Methods Culture-positive melioidosis cases presenting to Angkor Hospital for Children, a non-governmental paediatric hospital located in Siem Reap, Northern Cambodia, between 1st January 2009 and 31st December 2013 were identified by searches of hospital and laboratory databases and logbooks. Results One hundred seventy-three evaluable cases were identified, presenting from eight provinces. For Siem Reap province, the median commune level incidence was estimated to be 28-35 cases per 100,000 children <15 years per year. Most cases presented during the wet season, May to October. The median age at presentation was 5.7 years (range 8 days–15.9 years. Apart from undernutrition, co-morbidities were rare. Three quarters (131/173 of the children had localised infection, most commonly skin/soft tissue infection (60 cases or suppurative parotitis (51 cases. There were 39 children with B. pseudomallei bacteraemia: 29 (74.4% of these had clinical and/or radiological evidence of pneumonia. Overall mortality was 16.8% (29/173 with mortality in bacteraemic cases of 71.8% (28/39. At least seven children did not receive an antimicrobial with activity against B. pseudomallei prior to death. Conclusions This retrospective study demonstrated a considerable burden of melioidosis in Cambodian children. Given the high mortality associated with bacteraemic infection, there is an urgent need for greater awareness amongst healthcare professionals in Cambodia and other countries where melioidosis is known or suspected to be endemic. Empiric treatment guidelines should ensure suspected cases are treated early with appropriate antimicrobials.

  16. A New Take on an Old Remedy: Generating Antibodies against Multidrug-Resistant Gram-Negative Bacteria in a Postantibiotic World.

    Science.gov (United States)

    Motley, Michael P; Fries, Bettina C

    2017-01-01

    With the problem of multidrug-resistant Gram-negative pathogens becoming increasingly dire, new strategies are needed to protect and treat infected patients. Though abandoned in the past, monoclonal antibody therapy against Gram-negative bacteria remains a potential solution and has potential advantages over the broad-spectrum antibiotics they were once replaced by. This Perspective reviews the prospect of utilizing monoclonal antibody therapy against these pathogens, as well as the challenges of doing so and the current therapy targets under investigation.

  17. Role of microRNAs in sepsis.

    Science.gov (United States)

    Kingsley, S Manoj Kumar; Bhat, B Vishnu

    2017-07-01

    MicroRNAs have been found to be of high significance in the regulation of various genes and processes in the body. Sepsis is a serious clinical problem which arises due to the excessive host inflammatory response to infection. The non-specific clinical features and delayed diagnosis of sepsis has been a matter of concern for long time. MicroRNAs could enable better diagnosis of sepsis and help in the identification of the various stages of sepsis. Improved diagnosis may enable quicker and more effective treatment measures. The initial acute and transient phase of sepsis involves excessive secretion of pro-inflammatory cytokines which causes severe damage. MicroRNAs negatively regulate the toll-like receptor signaling pathway and regulate the production of inflammatory cytokines during sepsis. Likewise, microRNAs have shown to regulate the vascular barrier and endothelial function in sepsis. They are also involved in the regulation of the apoptosis, immunosuppression, and organ dysfunction in later stages of sepsis. Their importance at various levels of the pathophysiology of sepsis has been discussed along with the challenges and future perspectives. MicroRNAs could be key players in the diagnosis and staging of sepsis. Their regulation at various stages of sepsis suggests that they may have an important role in altering the outcome associated with sepsis.

  18. Uterine Sarcoma Presenting with Sepsis from Clostridium perfringens Endometritis in a Postmenopausal Woman

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    Mary J. Kao

    2018-01-01

    Full Text Available Clostridium perfringens is an anaerobic gram positive rod that is found in normal vaginal and cervical flora in 1–10% of healthy women. Uterine infection with Clostridium perfringens is seen rarely but is often related to underlying uterine pathology and can progress quickly to sepsis. Early recognition of sepsis, prompt treatment with antibiotics, and source control with surgical management allow for optimal chance of recovery. We present a case of a postmenopausal woman who presented with sepsis, vaginal bleeding, and back pain who was found to have Clostridium perfringens infection in the setting of undifferentiated uterine sarcoma.

  19. A Thermostable Salmonella Phage Endolysin, Lys68, with Broad Bactericidal Properties against Gram-Negative Pathogens in Presence of Weak Acids

    DEFF Research Database (Denmark)

    Oliveira, Hugo; Thiagarajan, Viruthachalam; Walmagh, Maarten

    2014-01-01

    Resistance rates are increasing among several problematic Gram-negative pathogens, a fact that has encouraged the development of new antimicrobial agents. This paper characterizes a Salmonella phage endolysin (Lys68) and demonstrates its potential antimicrobial effectiveness when combined...... with organic acids towards Gram-negative pathogens. Biochemical characterization reveals that Lys68 is more active at pH 7.0, maintaining 76.7% of its activity when stored at 4°C for two months. Thermostability tests showed that Lys68 is only completely inactivated upon exposure to 100°C for 30 min......, and circular dichroism analysis demonstrated the ability to refold into its original conformation upon thermal denaturation. It was shown that Lys68 is able to lyse a wide panel of Gram-negative bacteria (13 different species) in combination with the outer membrane permeabilizers EDTA, citric and malic acid...

  20. The Impact of Efflux Pump Inhibitors on the Activity of Selected Non-Antibiotic Medicinal Products against Gram-Negative Bacteria

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    Agnieszka E. Laudy

    2017-01-01

    Full Text Available The potential role of non-antibiotic medicinal products in the treatment of multidrug-resistant Gram-negative bacteria has recently been investigated. It is highly likely that the presence of efflux pumps may be one of the reasons for the weak activity of non-antibiotics, as in the case of some non-steroidal anti-inflammatory drugs (NSAIDs, against Gram-negative rods. The activity of eight drugs of potential non-antibiotic activity, active substance standards, and relevant medicinal products were analysed with and without of efflux pump inhibitors against 180 strains of five Gram-negative rod species by minimum inhibitory concentration (MIC value determination in the presence of 1 mM MgSO4. Furthermore, the influence of non-antibiotics on the susceptibility of clinical strains to quinolones with or without PAβN (Phe-Arg-β-naphthylamide was investigated. The impacts of PAβN on the susceptibility of bacteria to non-antibiotics suggests that amitriptyline, alendronate, nicergoline, and ticlopidine are substrates of efflux pumps in Gram-negative rods. Amitriptyline/Amitriptylinum showed the highest direct antibacterial activity, with MICs ranging 100–800 mg/L against all studied species. Significant decreases in the MIC values of other active substances (acyclovir, atorvastatin, and famotidine tested with pump inhibitors were not observed. The investigated non-antibiotic medicinal products did not alter the MICs of quinolones in the absence and in the presence of PAβN to the studied clinical strains of five groups of species.

  1. Antimicrobial Peptide Potency is Facilitated by Greater Conformational Flexibility when Binding to Gram-negative Bacterial Inner Membranes

    Science.gov (United States)

    Amos, Sarah-Beth T. A.; Vermeer, Louic S.; Ferguson, Philip M.; Kozlowska, Justyna; Davy, Matthew; Bui, Tam T.; Drake, Alex F.; Lorenz, Christian D.; Mason, A. James

    2016-11-01

    The interaction of antimicrobial peptides (AMPs) with the inner membrane of Gram-negative bacteria is a key determinant of their abilities to exert diverse bactericidal effects. Here we present a molecular level understanding of the initial target membrane interaction for two cationic α-helical AMPs that share structural similarities but have a ten-fold difference in antibacterial potency towards Gram-negative bacteria. The binding and insertion from solution of pleurocidin or magainin 2 to membranes representing the inner membrane of Gram-negative bacteria, comprising a mixture of 128 anionic and 384 zwitterionic lipids, is monitored over 100 ns in all atom molecular dynamics simulations. The effects of the membrane interaction on both the peptide and lipid constituents are considered and compared with new and published experimental data obtained in the steady state. While both magainin 2 and pleurocidin are capable of disrupting bacterial membranes, the greater potency of pleurocidin is linked to its ability to penetrate within the bacterial cell. We show that pleurocidin displays much greater conformational flexibility when compared with magainin 2, resists self-association at the membrane surface and penetrates further into the hydrophobic core of the lipid bilayer. Conformational flexibility is therefore revealed as a key feature required of apparently α-helical cationic AMPs for enhanced antibacterial potency.

  2. The epidemiology and clinical spectrum of melioidosis in a teaching hospital in a North-Eastern state of Malaysia: a fifteen-year review.

    Science.gov (United States)

    Zueter, AbdelRahman; Yean, Chan Yean; Abumarzouq, Mahmoud; Rahman, Zaidah Abdul; Deris, Zakuan Z; Harun, Azian

    2016-07-16

    Over the last two decades, many epidemiological studies were performed to describe risks and clinical presentations of melioidosis in endemic countries. We performed a retrospective analysis of 158 confirmed cases of melioidosis collected from medical records from 2001 to 2015 in Hospital Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia, in order to update the current status of melioidosis clinical epidemiology in this putatively high risk region of the country. Principal presentations in patients were lung infection in 65 (41.1 %), skin infection in 44 (27.8 %), septic arthritis/osteomyelitis in 20 (12.7 %) and liver infection in 19 (12.0 %). Bacteremic melioidosis was seen in most of patients (n = 121, 76.6 %). Focal melioidosis was seen in 124 (78.5 %) of patients and multi-focal melioidosis was reported in 45 (28.5 %) cases. Melioidosis with no evident focus was in 34 (21.5 %) patients. Fifty-four (34.2 %) patients developed septic shock. Internal organ abscesses and secondary foci in lungs and/or soft tissue were common. A total of 67 (41 %) cases presented during the monsoonal wet season. Death due to melioidosis was reported in 52 (32.9 %) patients, while relapses were occurred in 11 (7.0 %). Twelve fatal melioidosis cases seen in this study were directly attributed to the absence of prompt acute-phase treatment. Predisposing risk factors were reported in most of patients (n = 133, 84.2 %) and included diabetes (74.7 %), immune disturbances (9.5 %), cancer (4.4 %) and chronic kidney disease (11.4 %). On multivariate analysis, the only independent predictors of mortality were the presence of at least one co-morbid factor (OR 3.0; 95 % CI 1.1-8.4), the happening of septic shock (OR 16.5; 95 % CI 6.1-44.9) and age > 40 years (OR 6.47; 95 % CI 1.7-23.8). Melioidosis should be recognized as an opportunistic nonfatal infection for healthy person. Prompt early diagnosis and appropriate antibiotics administration and

  3. A resurgence of β-lactamase inhibitor combinations effective against multidrug-resistant Gram-negative pathogens.

    Science.gov (United States)

    Bush, Karen

    2015-11-01

    β-Lactamase inhibitors (BLIs) have played an important role in combatting β-lactam resistance in Gram-negative bacteria, but their effectiveness has diminished with the evolution of diverse and deleterious varieties of β-lactamases. In this review, a new generation of BLIs and inhibitor combinations is presented, describing epidemiological information, pharmacodynamic studies, resistance identification and current clinical status. Novel serine BLIs of major interest include the non-β-lactams of the diazabicyclo[3.2.1]octanone (DBO) series. The DBOs avibactam, relebactam and RG6080 inhibit most class A and class C β-lactamases, with selected inhibition of class D enzymes by avibactam. The novel boronic acid inhibitor RPX7009 has a similar inhibitory profile. All of these inhibitors are being developed in combinations that are targeting primarily carbapenemase-producing Gram-negative pathogens. Two BLI combinations (ceftolozane/tazobactam and ceftazidime/avibactam) were recently approved by the US Food and Drug Administration (FDA) under the designation of a Qualified Infectious Disease Product (QIDP). Other inhibitor combinations that have at least completed phase 1 clinical trials are ceftaroline fosamil/avibactam, aztreonam/avibactam, imipenem/relebactam, meropenem/RPX7009 and cefepime/AAI101. Although effective inhibitor combinations are in development for the treatment of infections caused by Gram-negative bacteria with serine carbapenemases, better options are still necessary for pathogens that produce metallo-β-lactamases (MBLs). The aztreonam/avibactam combination demonstrates inhibitory activity against MBL-producing enteric bacteria owing to the stability of the monobactam to these enzymes, but resistance is still an issue for MBL-producing non-fermentative bacteria. Because all of the inhibitor combinations are being developed as parenteral drugs, an orally bioavailable combination would also be of interest. Copyright © 2015 Elsevier B.V. and the

  4. A thermostable Salmonella phage endolysin, Lys68, with broad bactericidal properties against gram-negative pathogens in presence of weak acids.

    Directory of Open Access Journals (Sweden)

    Hugo Oliveira

    Full Text Available Resistance rates are increasing among several problematic Gram-negative pathogens, a fact that has encouraged the development of new antimicrobial agents. This paper characterizes a Salmonella phage endolysin (Lys68 and demonstrates its potential antimicrobial effectiveness when combined with organic acids towards Gram-negative pathogens. Biochemical characterization reveals that Lys68 is more active at pH 7.0, maintaining 76.7% of its activity when stored at 4°C for two months. Thermostability tests showed that Lys68 is only completely inactivated upon exposure to 100°C for 30 min, and circular dichroism analysis demonstrated the ability to refold into its original conformation upon thermal denaturation. It was shown that Lys68 is able to lyse a wide panel of Gram-negative bacteria (13 different species in combination with the outer membrane permeabilizers EDTA, citric and malic acid. While the EDTA/Lys68 combination only inactivated Pseudomonas strains, the use of citric or malic acid broadened Lys68 antibacterial effect to other Gram-negative pathogens (lytic activity against 9 and 11 species, respectively. Particularly against Salmonella Typhimurium LT2, the combinatory effect of malic or citric acid with Lys68 led to approximately 3 to 5 log reductions in bacterial load/CFUs after 2 hours, respectively, and was also able to reduce stationary-phase cells and bacterial biofilms by approximately 1 log. The broad killing capacity of malic/citric acid-Lys68 is explained by the destabilization and major disruptions of the cell outer membrane integrity due to the acidity caused by the organic acids and a relatively high muralytic activity of Lys68 at low pH. Lys68 demonstrates good (thermostability properties that combined with different outer membrane permeabilizers, could become useful to combat Gram-negative pathogens in agricultural, food and medical industry.

  5. Antimicrobial-induced endotoxaemia in patients with sepsis in the field of acute pyelonephritis.

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    Giamarellos-Bourboulis E

    2003-01-01

    Full Text Available BACKGROUND: In vitro results have shown that antimicrobial agents may induce the Gram-negative bacteria to release endotoxins (LPS, which in turn, could trigger the secretion of cytokines from monocytes. AIMS: To compare the effect of cefuroxime, netilmicin or ciprofloxacin on serum levels of LPS and tumour necrosis factor-alpha (TNFalpha. METHODS: Seventy-four patients with acute pyelonephritis caused by Gram-negative bacteria and signs of sepsis were randomly assigned to receive one of three intravenous regimens of cefuroxime, netilmicin or ciprofloxacin. Blood samples were collected before therapy and at specified time intervals for 96 hours after the initiation of treatment for the determination of serum levels of LPS and of TNFalpha. RESULTS: Patients treated with cefuroxime presented an early peak of LPS and of TNFalpha in serum two hours after the initiation of treatment compared to the other study groups. After that time interval, concentrations of LPS and TNFalpha were similar in all the study groups. Fever accompanied by endotoxaemia was still detected for 48 hours after the start of therapy in 36, 37.5 and 36% of patients treated with cefuroxime, netilmicin and ciprofloxacin respectively. The corresponding figures for these agents at 72 hours were 28, 12.5 and 24%, respective and 12, 4.2 and 4% at 96 hours (P value not significant. CONCLUSIONS: With the exception of an early peak in the serum levels of LPS and TNFalpha in patients treated with cefuroxime, no significant difference could be detected amongst the study groups as far as their effect on serum levels of LPS and TNFalpha were concerned. This suggests that these three antimicrobial agents may be administered safely at the early stages of sepsis.

  6. Seroepidemiology of melioidosis in children from a remote region of Papua New Guinea.

    Science.gov (United States)

    Diefenbach-Elstob, Tanya R; Graves, Patricia M; Burgess, Graham W; Pelowa, Daniel B; Warner, Jeffrey M

    2015-09-01

    The Balimo region in Papua New Guinea has previously been identified as melioidosis-endemic with a predilection for children. Where health resources are scarce, seroepidemiology can be used to assess exposure to Burkholderia pseudomallei and therefore risk of acquiring melioidosis. Logistic regression was used to determine associations between indirect haemagglutination assay (IHA) seroreactivity with environmental and demographic/cultural factors to aid in determining risk factors associated with exposure to B. pseudomallei in children. Of the 968 participants, 92.9% (899/968) were children, representing the majority of the community school population in the immediate Balimo region. Of these, 24.6% (221/899) were seropositive. Bathing in the lagoon (OR=2.679), drinking from the well or lagoon (OR=1.474), and being a member of the Siboko (OR=1.914) or Wagumisi (OR=1.942) clans were significantly associated with seropositivity. In the multivariate analysis, drinking from a well or lagoon (OR=1.713), and the Siboko (OR=2.341) and Wabadala (OR=2.022) clans were associated with seropositivity. This study in children supports observations that interactions with groundwater in this region are risk factors in acquiring melioidosis. Public health measures intended to limit this exposure may help reduce the risk of acquiring melioidosis in this remote community. Associations with clan structure may provide more cultural specific insights, however this requires further elucidation. © The Author 2014. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  7. Triggering receptor expressed on myeloid cells-2 fine-tunes inflammatory responses in murine Gram-negative sepsis

    DEFF Research Database (Denmark)

    Schmidt Thøgersen, Mariane; Gawish, Riem; Martins, Rui

    2015-01-01

    During infections, TLR-mediated responses require tight regulation to allow for pathogen removal, while preventing overwhelming inflammation and immunopathology. The triggering receptor expressed on myeloid cells (TREM)-2 negatively regulates inflammation by macrophages and impacts on phagocytosis...... was followed by an accelerated resolution and ultimately improved survival, associated with the induction of the negative regulator A20. Upon infection with Escherichia coli, the otherwise beneficial effect of an exaggerated early immune response in TREM-2(-/-) animals was counteracted by a 50% reduction...... in bacterial phagocytosis. In line with this, TREM-2(-/-) peritoneal macrophages (PMs) exhibited augmented inflammation following TLR4 stimulation, demonstrating the presence and negative regulatory functionality of TREM-2 on primary PMs. Significantly, we identified a high turnover rate because TREM-2 RNA...

  8. DNA/Ag Nanoparticles as Antibacterial Agents against Gram-Negative Bacteria

    Directory of Open Access Journals (Sweden)

    Tomomi Takeshima

    2015-03-01

    Full Text Available Silver (Ag nanoparticles were produced using DNA extracted from salmon milt as templates. Particles spherical in shape with an average diameter smaller than 10 nm were obtained. The nanoparticles consisted of Ag as the core with an outermost thin layer of DNA. The DNA/Ag hybrid nanoparticles were immobilized over the surface of cotton based fabrics and their antibacterial efficiency was evaluated using E. coli as the typical Gram-negative bacteria. The antibacterial experiments were performed according to the Antibacterial Standard of Japanese Association for the Functional Evaluation of Textiles. The fabrics modified with DNA/Ag nanoparticles showed a high enough inhibitory and killing efficiency against E. coli at a concentration of Ag ≥ 10 ppm.

  9. Two fatal cases of melioidosis on the Thai-Myanmar border [v2; ref status: indexed, http://f1000r.es/373

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    Cindy S. Chu

    2014-03-01

    Full Text Available Melioidosis is endemic in areas of Southeast Asia, however, there are no published reports from the Thai-Myanmar border. We report the first two documented cases of fatal melioidosis in this region. This is of great public health importance and highlights the need to both increase clinical awareness of melioidosis on the Thai-Myanmar border, and to assess the true burden of disease in the area through improved case detection and Burkholderia pseudomallei prevalence studies.

  10. Melioidosis: A Rare Cause of Liver Abscess

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    Peter Franz M. San Martin

    2016-01-01

    Full Text Available Case Presentation. This is a case of a 44-year-old male, farmer, known to be diabetic, presenting with two-week history of vague abdominal pain associated with high grade fever. Abdominal CT scan showed localized liver abscess at segment 8 measuring 7.5 × 6.8 × 6.1 cm. Patient subsequently underwent laparoscopic ultrasound guided pigtail insertion for drainage of abscess. Culture studies showed moderate growth of Burkholderia pseudomallei in which the patient completed seven days of IV Meropenem. On follow-up after 12 weeks of oral Sulfamethoxazole/Trimethoprim, taken twice a day, the patient remained asymptomatic with no residual findings based on the abdominal ultrasound. Discussion. Diagnosis of melioidosis, a known “great masquerader,” relies heavily on culture studies. Consensus with regard to the management of liver abscess caused by Burkholderia pseudomallei has not yet been established due to the rarity of cases. Surgical intervention through either a percutaneous or open drainage has shown good outcomes compared to IV antibiotics alone. In Philippines, the possibility of underreporting is highly plausible. This write-up serves not only to report a rare presentation of melioidosis but also to add to the number of cases reported in the country, possibly indicative of disease emergence.

  11. Long-term outcome of acute prosthetic joint infections due to gram-negative bacilli treated with retention of prosthesis.

    Science.gov (United States)

    Jaén, N; Martínez-Pastor, J C; Muñoz-Mahamud, E; García-Ramiro, S; Bosch, J; Mensa, J; Soriano, A

    2012-09-01

    To update the clinical information of the 47 patients with a prosthetic joint infection due to Gram-negative bacilli included in a previous study and to reassess the predictors of failure after a longer follow-up. Using the electronic files of our hospital, all the information regarding readmissions to the hospital, new surgical procedures and the reason for the new surgery (infection, aseptic loosening), and the last visit in the hospital were registered. The medical chart of the 35 patients that were considered in remission in the previous publication was reviewed. In 30 patients no clinical evidence of failure was detected and no additional surgery on the previously infected prosthesis was necessary and they were considered in long-term remission. In 5 cases a late complication was identified. One case had a reinfection due to coagulase-negative staphylococci after 22 months from the open debridement and required a 2-stage revision surgery. The other 4 cases developed an aseptic loosening and it was necessary to perform a 1-stage exchange. Receiving a fluoroquinolone when all the Gram-negatives involved in the infection were susceptible to fluoroquinolones was the only factor associated with remission in the univariate analysis (p=0.002). After a long-term follow-up, our results support the importance of using fluoroquinolones in acute PJI due to Gram-negative bacilli.

  12. Chronic suppurative joint effusion due to burkholderia pseudomallei: A case report

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    Madhavi Deshmukh

    2013-01-01

    Full Text Available Burkholderia pseudomallei, a Gram-negative bacillus is the causative agent of Melioidosis, a glanders-like disease, primarily a disease of animals. Melioidosis has been only a rare and sporadic disease in humans outside its endemic region. Currently, diagnosis of B. pseudomallei in the clinical laboratory is very difficult, owing to low awareness of physicians to the nonspecific clinical manifestations, lack of responsiveness among microbiologists outside endemic areas, identification systems in the average sentinel laboratory, and the biosafety conditions necessary to process these organisms. We report a case of chronic left hip joint effusion in a known case of diabetes mellitus. Gram stain of computed tomography (CT-guided aspirate from the joint revealed Gram-negative bacilli along with pus cells. Culture was confirmed as Burkholderia pseudomallei on Vitek2C, which was sensitive to ceftazidime and trimethoprim/sulfmethoxazole. Unfortunately, patient could not be started on appropriate antibiotics due to delay in detection and patient succumbed to severe septicemia. This case is reported to highlight importance of automated identification and sensitivity especially in nonendemic areas and unusual antibiogram of this organism for which disc diffusion method is not standardized.

  13. Transient sensitivity to nisin in cold-shocked Gram negatives.

    Science.gov (United States)

    Boziaris, I S; Adams, M R

    2000-09-01

    Rapid chilling in the presence of nisin caused a dose-dependent reduction in the populations of several Gram-negative bacteria, despite the fact that appreciable structural injury to the outer membrane was not detected. Pseudomonas aeruginosa was most affected, followed by Pseudomonas fragi, Salmonella enteritidis PT4, PT7 and Escherichia coli, respectively. Addition of nisin after the chilling treatment had no effect. The results are ascribed to a transient susceptibility caused by phase changes in the lipids associated with the outer membrane, which are rapidly reversed when the cells return to higher temperatures. Combinations of chilling shock, nisin and EDTA gave much lower reductions of Salmonella and Pseudomonas on chicken skin in comparison with broths. This is attributed to a buffering of the temperature shock experienced by adherent bacteria and binding of the nisin by food particles.

  14. Avances en el desarrollo de terapias neutralizantes en la sepsis Advances in the development of neutralizing therapies for sepsis

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    Maria Florencia Henning

    2006-06-01

    Full Text Available El lipopolisacárido bacteriano (LPS, también denominado endotoxina, es el constituyente mayoritario de la membrana externa de bacterias Gram negativas. Esta molécula es liberada de la bacteria a la circulación exhibiendo una amplia variedad de efectos tóxicos y pro-inflamatorios, los cuales están asociados al lípido A y a su vez están relacionados a la patogénesis de la sepsis. Muchos de los fenómenos fisiológicos producidos por el LPS resultan de la capacidad de esta molécula de activar las células del sistema inmune del huésped, entre ellas monocitos, macrófagos y leucocitos polimorfonucleares. Este proceso produce una inflamación local, proceso beneficioso para el huésped. Sin embargo, si la cantidad de LPS liberado excede cierta concentración crítica umbral, la exacerbada liberación de citoquinas inflamatorias como Factor de Necrosis Tumoral (TNF-a e interleuquinas (IL resulta en sepsis grave, lo que hace necesario encontrar nuevas opciones terapéuticas capaces de neutralizar la endotoxina circulante. En este artículo se presenta una revisión actualizada de los resultados experimentales obtenidos in vivo e in vitro empleando proteínas y péptidos sintéticos con la finalidad de neutralizar el LPS, y las perspectivas que en este área ofrece el uso de lipoproteínas, en particular la apolipoproteína A-I y formas mutantes o péptidos derivados de esta proteína.Lipopolisaccharide (LPS, also called endotoxin, is the major component of the external membrane in Gram negative bacteria. This molecule is released to circulation by the bacteria, producing a large variety of toxic and pro-inflammatory effects which are associated with lipid A as well as with sepsis pathogenesis. Many physiological phenomena produced by LPS arise from this molecule's capacity to activate cells in the host immune system such as monocytes, macrophages and polymorphonuclear leukocytes. This process leads to a local inflammation, and it is

  15. THE STUDY OF SERUM PROCALCITONIN LEVEL IN CORRELATION WITH SEPSIS

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    Girish M

    2016-09-01

    Full Text Available BACKGROUND Sepsis refers to the systemic response to serious infection. It can be response to the infection caused by any class of microorganism. The presence of bacteraemia is an indicator of disseminated infection and generally indicates a poorer prognosis when associated with localised disease. This study was undertaken to study the diagnostic and prognostic value of Procalcitonin (PCT in patients with sepsis. AIM To study the diagnostic and prognostic value of Procalcitonin (PCT in patients with sepsis. MATERIALS AND METHODS Fifty patients of age more than 18 years with sepsis admitted in KMC Hospitals, Mangalore, from August 2008 to June 2010 were subjects in the study after due permission from institution and informed consent from the patients. Diagnosis of sepsis was made according to criteria by ACCP/SCCM definition for sepsis. Definitive aetiological diagnosis requires isolation of microorganism from the blood and local site of infection, Gram stain and culture of the material from the primary site of infection for the microbial aetiology was taken. Other appropriate laboratory investigations depending upon requirement were done as mentioned in the investigations. RESULTS Out of total 50 patients, 23 patients were in group of sepsis, 14 were in group of severe sepsis while 13 had septic shock. Maximum number of the study patients were in the age group of 51-60 years. 52% of the study patients were male and 48% were female. Most common symptom in patients with sepsis was fever. Most common sign in the patient with sepsis is tachycardia followed by high temperature and then tachypnoea. Most common source of sepsis was respiratory infection followed by UTI. CONCLUSION Our data suggest the possibility that the addition of Procalcitonin into the standard workup of critically ill patients with suspected sepsis could increase diagnostic certainty and improve patient management.

  16. Comparison of in-house IgM and IgG ELISAs for the serodiagnosis of melioidosis in Malaysia.

    Science.gov (United States)

    Hii, Shirley Yi Fen; Ali, Noor Azila; Ahmad, Norazah; Amran, Fairuz

    2017-11-01

    Melioidosis is an endemic infectious disease in Southeast Asia and northern Australia, caused by Burkholderia pseudomallei. However, the incidence rate in Malaysia is not well documented. The high mortality rate and broad range of clinical presentations require rapid and accurate diagnosis for appropriate treatment. This study compared the efficacy of in-house IgM and IgG ELISA methods using a local B. pseudomallei strain. The diagnostic accuracy of the in-house IgG ELISA was better than that of the IgM ELISA: sensitivity (IgG: 84.71 %, IgM: 76.14 %) and specificity (IgG: 93.64 %, IgM: 90.17 %); positive predictive value (IgG: 86.75 %, IgM: 79.76 %) and negative predictive value (IgG: 92.57 %, IgM: 89.66 %); likelihood ratio (LR) [IgG: 13.32, IgM: 7.75 (LR+); IgG: 0.16, IgM: 0.26 (LR-)], and was supported by the observation of the absorbance value in comparisons between culture and serology sampling. In-house IgG ELISA was shown to be useful as an early diagnostic tool for melioidosis.

  17. In Vitro Antibacterial Activity of Several Plant Extracts and Oils against Some Gram-Negative Bacteria

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    Ayman Al-Mariri

    2014-01-01

    Full Text Available Background: Medicinal plants are considered new resources for producing agents that could act as alternatives to antibiotics in the treatment of antibiotic-resistant bacteria. The aim of this study was to evaluate the antibacterial activity of 28 plant extracts and oils against four Gram-negative bacterial species. Methods: Experimental, in vitro, evaluation of the activities of 28 plant extracts and oils as well as some antibiotics against E. coli O157:H7, Yersinia enterocolitica O9, Proteus spp., and Klebsiella pneumoniae was performed. The activity against 15 isolates of each bacterium was determined by disc diffusion method at a concentration of 5%. Microdilution susceptibility assay was used in order to determine the minimal inhibitory concentrations (MICs of the plant extracts, oils, and antibiotics. Results: Among the evaluated herbs, only Origanum syriacum L., Thymus syriacus Boiss., Syzygium aromaticum L., Juniperus foetidissima Wild, Allium sativum L., Myristica fragrans Houtt, and Cinnamomum zeylanicum L. essential oils and Laurus nobilis L. plant extract showed anti-bacterial activity. The MIC50 values of these products against the Gram-negative organisms varied from 1.5 (Proteus spp. and K. pneumoniae( and 6.25 µl/ml (Yersinia enterocolitica O9 to 12.5 µl/ml (E. coli O:157. Conclusion: Among the studied essential oils, O. syriacum L., T. syriacus Boiss., C. zeylanicum L., and S. aromaticum L. essential oils were the most effective. Moreover, Cephalosporin and Ciprofloxacin were the most effective antibiotics against almost all the studied bacteria. Therefore, O. syriacum L., T. syriacus Boiss., C. zeylanicum L., and S. aromaticum L. could act as bactericidal agents against Gram-negative bacteria.

  18. Biodefense-driven murine model of pneumonic melioidosis.

    Science.gov (United States)

    Jeddeloh, J A; Fritz, D L; Waag, D M; Hartings, J M; Andrews, G P

    2003-01-01

    A whole-body mouse model of pneumonic melioidosis was established for future evaluation of biodefense vaccine candidates. The aerosol 50% lethal doses of Burkholderia pseudomallei strain 1026b for BALB/c and C57BL/6 mice and the times to death, dissemination in organs, and tissue loads after exposure of the mice to low- and high-dose aerosols are reported. In addition, rpsL mutant backgrounds were attenuated in this acute model of disease.

  19. Dose-Dependent Antimicrobial Activity of Silver Nanoparticles on Polycaprolactone Fibers against Gram-Positive and Gram-Negative Bacteria

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    Erick Pazos-Ortiz

    2017-01-01

    Full Text Available The adhesion ability and adaptability of bacteria, coupled with constant use of the same bactericides, have made the increase in the diversity of treatments against infections necessary. Nanotechnology has played an important role in the search for new ways to prevent and treat infections, including the use of metallic nanoparticles with antibacterial properties. In this study, we worked on the design of a composite of silver nanoparticles (AgNPS embedded in poly-epsilon-caprolactone nanofibers and evaluated its antimicrobial properties against various Gram-positive and Gram-negative microorganisms associated with drug-resistant infections. Polycaprolactone-silver composites (PCL-AgNPs were prepared in two steps. The first step consisted in the reduction in situ of Ag+ ions using N,N-dimethylformamide (DMF in tetrahydrofuran (THF solution, and the second step involved the simple addition of polycaprolactone before electrospinning process. Antibacterial activity of PCL-AgNPs nanofibers against E. coli, S. mutans, K. pneumoniae, S. aureus, P. aeruginosa, and B. subtilis was evaluated. Results showed sensibility of E. coli, K. pneumoniae, S. aureus, and P. aeruginosa, but not for B. subtilis and S. mutans. This antimicrobial activity of PCL-AgNPs showed significant positive correlations associated with the dose-dependent effect. The antibacterial property of the PCL/Ag nanofibers might have high potential medical applications in drug-resistant infections.

  20. Intravenous Colistin Use for Multidrug-Resistant Gram-Negative Infections in Pediatric Patients.

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    Karaaslan, Ayşe; Çağan, Eren; Kadayifci, Eda Kepenekli; Atıcı, Serkan; Akkoç, Gülşen; Yakut, Nurhayat; Demir, Sevliya Öcal; Soysal, Ahmet; Bakır, Mustafa

    2016-11-01

    The emergence of infections due to multidrug-resistant Gram-negative bacilli (MDR-GNB) has led to the resurrection of colistin use. The data on colistin use and drug-related adverse effects in children are scarce. In this study, we aimed to evaluate the clinical efficacy and safety of colistin use in critically ill pediatric patients. This study has a retrospective study design. Sixty-one critically ill children were identified through the department's patient files archive during the period from January 2011 to November 2014. Twenty-nine females and thirty-two males with a mean±standard deviation (SD) age of 61±9 months (range 0-216, median 12 months) received IV colistin due to MDR-GNB infections. Bacteremia (n=23, 37.7%) was the leading diagnosis, followed by pneumonia (n=19, 31%), clinical sepsis (n=7, 11.4%), wound infection (n=6, 9.8%), urinary tract infection (n=5, 8.1%) and meningitis (n=1, 1.6%). All of the isolates were resistant to carbapenems; however, all were susceptible to colistin. The isolated microorganisms in decreasing order of frequency were: Acinetobacter baumanni (n=27, 44.2%), Pseudomonas aeruginosa (n=17, 27.8%), Klebsiella pneumoniae (n=6, 9.8%), K. pneumoniae and Stenotrophomonas maltophilia (n=1, 1.6%), K. pneumoniae and A. baumanni (n=1, 1.6%), K. oxytoca (n=1, 1.6%) and Enterobacter cloacae (n=1, 1.6%). In seven patients, no microorganisms were detected; however, five of these patients were colonized by carbapenem-resistant K. pneumoniae. The mean duration of colistin therapy was 12 days (range 3-45). Colistin was administered concomitantly with one of the following antibiotics: carbapenem (n=50, %82), ampicillin-sulbactam (n=5, 8%), quinolones (n=5, 8%), rifampicin (n=1, 1.6%). Carbapenem was the most frequently used antibiotic. Nephrotoxicity was observed in only 1 patient, and we did not observe neurotoxicity in this study. All the patients received intravenous colistin (colisthimethate) at a dosage of 5 mg/kg daily by dividing it

  1. Intravenous Colistin Use for Multidrug-Resistant Gram-Negative Infections in Pediatric Patients

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    Ayşe Karaaslan

    2016-12-01

    Full Text Available Background: The emergence of infections due to multidrug-resistant Gram-negative bacilli (MDR-GNB has led to the resurrection of colistin use. The data on colistin use and drug-related adverse effects in children are scarce. Aims: In this study, we aimed to evaluate the clinical efficacy and safety of colistin use in critically ill pediatric patients. Study Design: This study has a retrospective study design. Methods: Sixty-one critically ill children were identified through the department’s patient files archive during the period from January 2011 to November 2014. Results: Twenty-nine females and thirty-two males with a mean±standard deviation (SD age of 61±9 months (range 0-216, median 12 months received IV colistin due to MDR-GNB infections. Bacteremia (n=23, 37.7% was the leading diagnosis, followed by pneumonia (n=19, 31%, clinical sepsis (n=7, 11.4%, wound infection (n=6, 9.8%, urinary tract infection (n=5, 8.1% and meningitis (n=1, 1.6%. All of the isolates were resistant to carbapenems; however, all were susceptible to colistin. The isolated microorganisms in decreasing order of frequency were: Acinetobacter baumanni (n=27, 44.2%, Pseudomonas aeruginosa (n=17, 27.8%, Klebsiella pneumoniae (n=6, 9.8%, K. pneumoniae and Stenotrophomonas maltophilia (n=1, 1.6%, K. pneumoniae and A. baumanni (n=1, 1.6%, K. oxytoca (n=1, 1.6% and Enterobacter cloacae (n=1, 1.6%. In seven patients, no microorganisms were detected; however, five of these patients were colonized by carbapenem-resistant K. pneumoniae. The mean duration of colistin therapy was 12 days (range 3-45. Colistin was administered concomitantly with one of the following antibiotics: carbapenem (n=50, %82, ampicillin-sulbactam (n=5, 8%, quinolones (n=5, 8%, rifampicin (n=1, 1.6%. Carbapenem was the most frequently used antibiotic. Nephrotoxicity was observed in only 1 patient, and we did not observe neurotoxicity in this study. All the patients received intravenous colistin

  2. Different phenotypic and molecular mechanisms associated with multidrug resistance in Gram-negative clinical isolates from Egypt

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    Helmy OM

    2017-12-01

    Full Text Available Omneya M Helmy, Mona T Kashef Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, Egypt Objectives: We set out to investigate the prevalence, different mechanisms, and clonal relatedness of multidrug resistance (MDR among third-generation cephalosporin-resistant Gram-negative clinical isolates from Egypt.Materials and methods: A total of 118 third-generation cephalosporin-resistant Gram-negative clinical isolates were included in this study. Their antimicrobial susceptibility pattern was determined using Kirby–Bauer disk diffusion method. Efflux pump-mediated resistance was tested by the efflux-pump inhibitor-based microplate assay using chlorpromazine. Detection of different aminoglycoside-, β-lactam-, and quinolone-resistance genes was done using polymerase chain reaction. The genetic diversity of MDR isolates was investigated using random amplification of polymorphic DNA.Results: Most of the tested isolates exhibited MDR phenotypes (84.75%. The occurrence of efflux pump-mediated resistance in the different MDR species tested was 40%–66%. Acinetobacter baumannii isolates showed resistance to most of the tested antibiotics, including imipenem. The blaOXA-23-like gene was detected in 69% of the MDR A. baumannii isolates. The MDR phenotype was detected in 65% of Pseudomonas aeruginosa isolates, of which only 23% exhibited efflux pump-mediated resistance. On the contrary, efflux-mediated resistance to piperacillin and gentamicin was recorded in 47.5% of piperacillin-resistant and 25% of gentamicin-resistant MDR Enterobacteriaceae. Moreover, the plasmid-mediated quinolone-resistance genes (aac(6’-Ib-cr, qnrB, and qnrS were detected in 57.6% and 83.33% of quinolone-resistant MDR Escherichia coli and Klebsiella pneumoniae isolates, respectively. The β-lactamase-resistance gene blaSHV-31 was detected for the first time in one MDR K. pneumoniae isolate from an endotracheal tube specimen in Egypt

  3. Spread of resistant gram negatives in a Sri Lankan intensive care unit.

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    Tissera, Kavinda; Liyanapathirana, Veranja; Dissanayake, Nilanthi; Pinto, Vasanthi; Ekanayake, Asela; Tennakoon, Manjula; Adasooriya, Dinuka; Nanayakkara, Dulmini

    2017-07-11

    Infections with multi drug resistant (MDR) organisms are a major problem in intensive care units (ICUs). Proper infection control procedures are mandatory to combat the spread of resistant organisms within ICUs. Well stablished surveillance programmes will enhance the adherence of the staff to infection control protocols. The study was conducted to assess the feasibility of using basic molecular typing methods and routine hospital data for laboratory surveillance of resistance organisms in resource limited settings. A retrospective study was conducted using consecutive Gram negative isolates obtained from an ICU over a six month period. Antibiotic sensitivity patterns and random amplified polymorphic DNA (RAPD) based typing was performed on the given isolates. Of the seventy isolates included in the study, seven were E.coli. All E.coli were MDRs and Extended Spectrum β lactamse (ESBL) producers carrying bla CTX-M . Fourteen isolates were K.pneumoniae, and all were MDRs and ESBL producers. All K.pneumoniae harboured bla SHV while 13 harboured bla CTX-M . The MDR rate among P.aeruginosa was 13% (n=15) while all acinetobacters (n=30) were MDRs. Predominant clusters were identified within all four types of Gram negatives using RAPD and the ICU stay of patients overlapped temporally. We propose that simple surveillance methods like RAPD based typing and basic hospital data can be used to convince hospital staff to adhere to infection control protocols more effectively, in low and middle income countries.

  4. Pulmonary and systemic inflammatory responses in rabbits with gram-negative pneumonia.

    Science.gov (United States)

    Fox-Dewhurst, R; Alberts, M K; Kajikawa, O; Caldwell, E; Johnson, M C; Skerrett, S J; Goodman, R B; Ruzinski, J T; Wong, V A; Chi, E Y; Martin, T R

    1997-06-01

    The major goals of this study were to define the relationships between intrapulmonary and systemic inflammatory responses in animals with gram-negative pneumonia. We treated rabbits with intrapulmonary Escherichia coli (1 x 10(7) to 1 x 10(10) cfu/ml), and then measured physiologic, cellular, and molecular events in the lungs and systemic circulation for 24 h. The treatment protocols resulted in groups of animals that mimicked the stages of the septic inflammatory response in humans. Animals treated with low inocula had systemic changes consistent with systemic inflammatory response syndrome and cleared the bacteria and inflammatory products from the lungs. Animals treated with high inocula failed to clear bacteria from the lungs, had severe intrapulmonary inflammatory responses, and developed septic shock. Intrapulmonary leukocyte recruitment was directly related to the size of the bacterial inoculum, but lung protein accumulation was not. Tumor neurosis factor-alpha (TNF-alpha), interleukin-8 (IL-8), and GRO were detectable in lung lavage fluid at 4 h and declined by 24 h in animals that cleared intrapulmonary E. coli. In contrast, lavage TNF-alpha, IL-8, and GRO increased over 24 h in animals that failed to clear intrapulmonary bacteria. MCP-1 increased between 4 h and 24 h in the lungs of all of the animals as the histologic response evolved from neutrophilic to mononuclear cell predominance. Thus, the intensity of systemic inflammatory and physiologic responses to intrapulmonary gram-negative infection depends on the inoculum size and whether the bacteria are cleared from or proliferate in the lungs. The results provide experimental support for the recently proposed classification of septic responses in humans.

  5. Imipenem-resistant Gram-negative bacterial isolates carried by persons upon medical examination in Korea.

    Science.gov (United States)

    Kim, So Yeon; Shin, Sang Yop; Rhee, Ji-Young; Ko, Kwan Soo

    2017-08-01

    Carbapenem-resistant Gram-negative bacteria (CR-GNB) have emerged and disseminated worldwide, become a great concern worldwide including Korea. The prevalence of fecal carriage of imipenem-resistant Gram-negative bacteria (IR-GNB) in persons in Korea was investigated. Stool samples were collected from 300 persons upon medical examination. Samples were screened for IR-GNB by using MacConkey agar with 2 μl/ml imipenem. Species were identified by 16S rRNA gene sequence analysis, and antimicrobial susceptibility was determined by the broth microdilution method. In total, 82 IR-GNB bacterial isolates were obtained from 79 (26.3%) out of 300 healthy persons. Multilocus sequence typing analysis showed very high diversity among IR P. aeruginosa, S. maltophilia, and E. cloacae isolates, and pulsed-field gel electrophoresis revealed five main pulsotypes of IR P. mirabilis. As for the presence of metallo-β-lactamases (MBLs), only one IMP-25-producing S. marcescens isolate was identified. Although only one carbapenemase-producing isolate was identified, the high colonization rates with IR-GNB isolates in this study is notable because carriers may be a reservoir for the dissemination of resistant pathogens within the community as well as in health care institutions.

  6. Antibacterial activity of crude extract of Punica granatum pericarp on pathogenic Gram-negative bacilli.

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    Voravuthikunchai, S.

    2005-08-01

    Full Text Available The objective of this study was to investigate the effect of crude extracts of Punica granatum Linn. pericarp with 3 different solvents against pathogenic Gram-negative bacilli. Ethanolic extracts showed the antibacterial activity against all strains tested including enterohaemorrhagic Escherichia coli 4 strains (E. coli O157: H7, E. coli O26: H11, E. coli O111: NM, E. coli O22, Pseudomonas aeruginosa, Shigella boydii and Salmonella london. Inhibition zones ranged from 10.02 to 19.15 mm. Minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC ranged from 0.09 to 3.13 mg/ml and 3.13 to 25 mg/ml, respectively. Aqueous extract had low antibacterial activity while crude chloroform extracts had no effect on the growth of these strains. Ethyl acetate and n-butanol fractions of P. granatum pericarp demonstrated high activity with the best MIC and MBC values of 0.02 to 0.78 mg/ml and 0.19 to 6.25 mg/ml, respectively. As ethanolic extract of P. granatum was very effective against these pathogenic bacteria, further investigation on this plant species may provide alternative, but bioactive, medicines for the treatment of Gram-negative bacterial infection.

  7. Two fatal cases of melioidosis on the Thai-Myanmar border [v1; ref status: indexed, http://f1000r.es/2os

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    Cindy S. Chu

    2014-01-01

    Full Text Available Melioidosis is endemic in areas of Southeast Asia, however, there are no published reports from the Thai-Myanmar border.  We report the first two cases of fatal melioidosis in this region. This is of great public health importance and highlights the need to increase clinical awareness of melioidosis on the Thai-Myanmar border and to assess the true burden of disease in the area through improved case detection and Burkholderia pseudomallei prevalence studies.

  8. Colonization of long term care facility patients with MDR-Gram-negatives during an Acinetobacter baumannii outbreak

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    Ines Zollner-Schwetz

    2017-05-01

    Full Text Available Abstract Background We aimed to determine the prevalence of colonization by multidrug-resistant Gram-negative bacteria including ESBL-producing enterobacteriaceae, carbapenem-resistant enterobacteriaceae, Pseudomonas aeruginosa and Acinetobacter baumannii at two wards caring long term for patients with disorder of consciousness at the Geriatric Health Centers Graz, Austria. During our study we detected two A. baumannii outbreaks. Methods In August 2015, we conducted a point-prevalence study. Inguinal and perianal swabs were taken from 38 patients and screened for multidrug-resistant Gram-negative rods using standard procedures. Six months after the initial investigation all patients were sampled again and use of antibiotics during the past 6 months and mortality was registered. Genetic relatedness of bacteria was evaluated by DiversiLab system. Results Fifty percent of patients were colonized by multidrug-resistant Gram-negative isolates. Five patients harboured ESBL-producing enterobacteriaceae. No carbapenem-resistant enterobacteriaceae were detected. 13/38 patients were colonized by A. baumannii isolates (resistant to ciprofloxacin but susceptible to carbapenems. There was a significant difference in the prevalence of colonization by A. baumannii between ward 2 and ward 1 (60% vs. 5.6%, p < 0.001. Two clusters of A. baumannii isolates were identified including one isolate detected on a chair in a patient’s room. Conclusions We detected a high prevalence of two multidrug-resistant A. baumannii strains in patients with disorder of consciousness at a LTCF in Graz, Austria. Our findings strongly suggest nosocomial cross-transmission between patients. An active surveillance strategy is warranted to avoid missing newly emerging pathogens.

  9. Colonization of long term care facility patients with MDR-Gram-negatives during an Acinetobacter baumannii outbreak.

    Science.gov (United States)

    Zollner-Schwetz, Ines; Zechner, Elisabeth; Ullrich, Elisabeth; Luxner, Josefa; Pux, Christian; Pichler, Gerald; Schippinger, Walter; Krause, Robert; Leitner, Eva

    2017-01-01

    We aimed to determine the prevalence of colonization by multidrug-resistant Gram-negative bacteria including ESBL-producing enterobacteriaceae, carbapenem-resistant enterobacteriaceae, Pseudomonas aeruginosa and Acinetobacter baumannii at two wards caring long term for patients with disorder of consciousness at the Geriatric Health Centers Graz, Austria. During our study we detected two A. baumannii outbreaks. In August 2015, we conducted a point-prevalence study. Inguinal and perianal swabs were taken from 38 patients and screened for multidrug-resistant Gram-negative rods using standard procedures. Six months after the initial investigation all patients were sampled again and use of antibiotics during the past 6 months and mortality was registered. Genetic relatedness of bacteria was evaluated by DiversiLab system. Fifty percent of patients were colonized by multidrug-resistant Gram-negative isolates. Five patients harboured ESBL-producing enterobacteriaceae. No carbapenem-resistant enterobacteriaceae were detected. 13/38 patients were colonized by A. baumannii isolates (resistant to ciprofloxacin but susceptible to carbapenems). There was a significant difference in the prevalence of colonization by A. baumannii between ward 2 and ward 1 (60% vs. 5.6%, p  < 0.001). Two clusters of A. baumannii isolates were identified including one isolate detected on a chair in a patient's room. We detected a high prevalence of two multidrug-resistant A. baumannii strains in patients with disorder of consciousness at a LTCF in Graz, Austria. Our findings strongly suggest nosocomial cross-transmission between patients. An active surveillance strategy is warranted to avoid missing newly emerging pathogens.

  10. Determination of the irradiation dose for the inhibition (D-10 radiation doses) of some gram negative and gram positive bacteria in peptone saline water

    International Nuclear Information System (INIS)

    Ayhan, H.; Tutluer, H.

    1994-01-01

    Determination of the irradiation dose for the inhibition of some pathogenic bacteria which cause food poisoning and spoilage were aimed. For this purpose, Salmonella typhi, Salmonella typhimurium,Salmonella enteridits,Klebsiella pneumonia, Pseudomonas fluorescence,Proteus vulgaris, Aeromonas hydrophila ,(gram-negative bacteria) and Bacillus cereus, Staphylococcus aureus strain 24,Staphylococcus aureus ATCC 6538 P,Staphylococcus epidermidis strain 115 and Clostridium perfringens A4TTK,(gram-positive bacteria) were used.Sensitivity of above mentioned bacteria to gamma rays (source Cs-137) was examined in saline with 0.1% peptone at different temperatures.Survivor plots (log.10 number of survivors versus dose) were determined by regression analysis of the data.Decimal reduction doses (D values in kGy) were calculated as the slope obtained from the regression analysis

  11. The warmer the weather, the more gram-negative bacteria - impact of temperature on clinical isolates in intensive care units.

    Science.gov (United States)

    Schwab, Frank; Gastmeier, Petra; Meyer, Elisabeth

    2014-01-01

    We investigated the relationship between average monthly temperature and the most common clinical pathogens causing infections in intensive care patients. A prospective unit-based study in 73 German intensive care units located in 41 different hospitals and 31 different cities with total 188,949 pathogen isolates (102,377 Gram-positives and 86,572 Gram-negatives) from 2001 to 2012. We estimated the relationship between the number of clinical pathogens per month and the average temperature in the month of isolation and in the month prior to isolation while adjusting for confounders and long-term trends using time series analysis. Adjusted incidence rate ratios for temperature parameters were estimated based on generalized estimating equation models which account for clustering effects. The incidence density of Gram-negative pathogens was 15% (IRR 1.15, 95%CI 1.10-1.21) higher at temperatures ≥ 20°C than at temperatures below 5°C. E. cloacae occurred 43% (IRR=1.43; 95%CI 1.31-1.56) more frequently at high temperatures, A. baumannii 37% (IRR=1.37; 95%CI 1.11-1.69), S. maltophilia 32% (IRR=1.32; 95%CI 1.12-1.57), K. pneumoniae 26% (IRR=1.26; 95%CI 1.13-1.39), Citrobacter spp. 19% (IRR=1.19; 95%CI 0.99-1.44) and coagulase-negative staphylococci 13% (IRR=1.13; 95%CI 1.04-1.22). By contrast, S. pneumoniae 35% (IRR=0.65; 95%CI 0.50-0.84) less frequently isolated at high temperatures. For each 5°C increase, we observed a 3% (IRR=1.03; 95%CI 1.02-1.04) increase of Gram-negative pathogens. This increase was highest for A. baumannii with 8% (IRR=1.08; 95%CI 1.05-1.12) followed by K. pneumoniae, Citrobacter spp. and E. cloacae with 7%. Clinical pathogens vary by incidence density with temperature. Significant higher incidence densities of Gram-negative pathogens were observed during summer whereas S. pneumoniae peaked in winter. There is increasing evidence that different seasonality due to physiologic changes underlies host susceptibility to different bacterial pathogens

  12. Antibacterial activity and interactions of plant essential oil combinations against Gram-positive and Gram-negative bacteria

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    Cristina Anamaria Semeniuc

    2017-04-01

    Full Text Available The aim of this study was to compare the antibacterial effects of several essential oils (EOs alone and in combination against different Gram-positive and Gram-negative bacteria associated with food products. Parsley, lovage, basil, and thyme EOs, as well as their mixtures (1:1, v/v, were tested against Bacillus cereus, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Salmonella typhimurium. The inhibitory effects ranged from strong (thyme EO against E. coli to no inhibition (parsley EO against P. aeruginosa. Thyme EO exhibited strong (against E. coli, moderate (against S. typhimurium and B. cereus, or mild inhibitory effects (against P. aeruginosa and S. aureus, and basil EO showed mild (against E. coli and B. cereus or no inhibitory effects (against S. typhimurium, P. aeruginosa, and S. aureus. Parsley and lovage EOs revealed no inhibitory effects against all tested strains. Combinations of lovage/thyme and basil/thyme EOs displayed antagonistic effects against all bacteria, parsley/thyme EOs against B. cereus, S. aureus, P. aeruginosa, and E. coli, and lovage/basil EOs against B. cereus and E. coli. Combinations of parsley/lovage and parsley/basil EOs exhibited indifferent effects against all bacteria. The combination of lovage/basil EO showed indifferent effect against S. aureus, P. aeruginosa, and S. typhimurium, and the combination parsley/thyme EO against S. typhimurium. Thyme EO has the highest percentage yield and antibacterial potential from all tested formulations; its combination with parsley, lovage, and basil EOs determines a reduction of its antibacterial activity. Hence, it is recommended to be used alone as the antibacterial agent.

  13. Sepsis due to linezolid resistant Staphylococcus cohnii and Staphylococcus kloosii: first reports of linezolid resistance in coagulase negative staphylococci from India.

    Science.gov (United States)

    Peer, M A; Nasir, R A; Kakru, D K; Fomda, B A; Bashir, G; Sheikh, I A

    2011-01-01

    Linezolid, a viable alternative to vancomycin against methicillin resistant staphylococcal isolates, has been in use for a decade around the globe. However, resistance against staphylococci remains extremely rare and unreported from most of the Asian countries. Herein, we report two cases of linezolid resistant, coagulase negative staphylococcal sepsis for the first time from India. The first case was an 18-year-old burn patient, who, after a major graft surgery, landed in sepsis, and linezolid resistant Staphylococcus cohnii with an minimum inhibitory concentration (MIC) of >256 μg/ml by both broth microdilution and Etest, was isolated from multiple blood cultures. The second patient was a 60-year-old male with an intracranial bleed and sepsis, from whose blood cultures, linezolid resistant Staphylococcus kloosii was repeatedly isolated. Linezolid MIC was >32 μg/ml by broth microdilution and >16 μg/ml by Etest.

  14. Sepsis due to linezolid resistant Staphylococcus cohnii and Staphylococcus kloosii: First reports of linezolid resistance in coagulase negative staphylococci from India

    Directory of Open Access Journals (Sweden)

    M A Peer

    2011-01-01

    Full Text Available Linezolid, a viable alternative to vancomycin against methicillin resistant staphylococcal isolates, has been in use for a decade around the globe. However, resistance against staphylococci remains extremely rare and unreported from most of the Asian countries. Herein, we report two cases of linezolid resistant, coagulase negative staphylococcal sepsis for the first time from India. The first case was an 18-year-old burn patient, who, after a major graft surgery, landed in sepsis, and linezolid resistant Staphylococcus cohnii with an minimum inhibitory concentration (MIC of >256 μg/ml by both broth microdilution and Etest, was isolated from multiple blood cultures. The second patient was a 60-year-old male with an intracranial bleed and sepsis, from whose blood cultures, linezolid resistant Staphylococcus kloosii was repeatedly isolated. Linezolid MIC was >32 μg/ml by broth microdilution and >16 μg/ml by Etest.

  15. [Detection of endotoxins of Gram-negative bacteria on the basis of electromagnetic radiation frequency spectrum].

    Science.gov (United States)

    Likhoded, V G; Kuleshova, N V; Sergieva, N V; Konev, Iu V; Trubnikova, I A; Sudzhian, E V

    2007-01-01

    Method of Gram-negative bacteria endotoxins detection on the basis of their own spectrum of electromagnetic radiation frequency was developed. Frequency spectrum typical for chemotype Re glycolipid, which is a part of lypopolysaccharides in the majority of Gram-negative bacteria, was used. Two devices--"Mini- Expert-DT" (manufactured by IMEDIS, Moscow) and "Bicom" (manufactured by Regumed, Germany)--were used as generators of electromagnetic radiation. Detection of endotoxin using these devices was performed by electropuncture vegetative resonance test. Immunoenzyme reaction with antibodies to chemotype Re glycolipid was used during analysis of preparations for assessment of resonance-frequency method specificity. The study showed that resonance-frequency method can detect lypopolysaccharides of different enterobacteria in quantities up to 0.1 pg as well as bacteria which contain lypopolysaccharides. At the same time, this method does not detect such bacteria as Staphylococcus aureus, Bifidobacterium spp., Lactobacillus spp., and Candida albicans. The method does not require preliminary processing of blood samples and can be used for diagnostics of endotoxinemia, and detection of endotoxins in blood samples or injection solutions.

  16. Enhancing pathogen identification in patients with meningitis and a negative Gram stain using the BioFire FilmArray(®) Meningitis/Encephalitis panel.

    Science.gov (United States)

    Wootton, Susan H; Aguilera, Elizabeth; Salazar, Lucrecia; Hemmert, Andrew C; Hasbun, Rodrigo

    2016-04-21

    Meningitis with a negative cerebrospinal (CSF) Gram stain represents a diagnostic and therapeutic challenge. The purpose of our study was to evaluate the performance of the BioFire FilmArray(®) Meningitis/Encephalitis (FA ME) panel in patients presenting with community-acquired meningitis with a negative Gram stain. CSF from 48 patients with community-acquired meningitis with a negative Gram stain admitted to four hospitals in Houston, TX underwent additional testing by the FA ME. FA ME results were compared to results obtained as part of routine evaluation. The panel detected pathogens not previously identified in 11 (22.9 %) of 48, but did not detect pathogens identified by standard technique (West Nile virus, Histoplasma) in 5 (15.2 %) patients. Rapid testing for the most common pathogens causing meningitis will aid in the diagnosis and treatment of patients with meningitis.

  17. Purification and characterization of tenecin 4, a new anti-Gram-negative bacterial peptide, from the beetle Tenebrio molitor.

    Science.gov (United States)

    Chae, Jun-Ho; Kurokawa, Kenji; So, Young-In; Hwang, Hyun Ok; Kim, Min-Su; Park, Ji-Won; Jo, Yong-Hun; Lee, Yong Seok; Lee, Bok Luel

    2012-03-01

    The biochemical characterization of novel antimicrobial peptides (AMPs) and the determination of ligand molecules that induce AMP production are essential for understanding the host innate immune response in insects. Here, we purified a new 14-kDa AMP, named tenecin 4, from the larval hemolymph of the beetle Tenebrio molitor. Tenecin 4 contains 14% glycine residues and has moderate similarities both to the C-terminal region of Drosophila attacin and to silk-moth gloverin proteins. Purified tenecin 4 showed bactericidal activity against Gram-negative Escherichia coli but not against Gram-positive Bacillus subtilis or the fungus Candida albicans. Tenecin 4 production was induced by Toll cascade-activating ligands, such as β-1,3-glucan, lysine-type peptidoglycan and active Spätzle, and by the probable Imd pathway-activating ligand monomeric meso-diaminopimelic acid-type peptidoglycan. Taken together, these data show that tenecin 4 is a defense protein against Gram-negative pathogens and is induced by multiple ligands in Tenebrio larvae. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Effect of extended infusion of meropenem and nebulized amikacin on Gram-negative multidrug-resistant ventilator-associated pneumonia

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    Mona Ahmed Ammar

    2018-01-01

    Conclusions: Adding nebulized amikacin to systemic antibiotics in patients with VAP caused by Gram-negative MDRO may offer efficacy benefits, and the use of extended infusions of meropenem could improve the clinical outcomes in critically ill populations.

  19. Renew or die: The molecular mechanisms of peptidoglycan recycling and antibiotic resistance in Gram-negative pathogens.

    Science.gov (United States)

    Domínguez-Gil, Teresa; Molina, Rafael; Alcorlo, Martín; Hermoso, Juan A

    2016-09-01

    Antimicrobial resistance is one of the most serious health threats. Cell-wall remodeling processes are tightly regulated to warrant bacterial survival and in some cases are directly linked to antibiotic resistance. Remodeling produces cell-wall fragments that are recycled but can also act as messengers for bacterial communication, as effector molecules in immune response and as signaling molecules triggering antibiotic resistance. This review is intended to provide state-of-the-art information about the molecular mechanisms governing this process and gather structural information of the different macromolecular machineries involved in peptidoglycan recycling in Gram-negative bacteria. The growing body of literature on the 3D structures of the corresponding macromolecules reveals an extraordinary complexity. Considering the increasing incidence and widespread emergence of Gram-negative multidrug-resistant pathogens in clinics, structural information on the main actors of the recycling process paves the way for designing novel antibiotics disrupting cellular communication in the recycling-resistance pathway. Copyright © 2016. Published by Elsevier Ltd.

  20. Vitreous System Ag2O –ZnO–B2O3 Action Against Gram Negative Bacteria

    Directory of Open Access Journals (Sweden)

    Razvan Stefan

    2010-05-01

    Full Text Available In this work the ability of the system xAg2O  (100-x [45ZnO55B2O3] oxide glasses to inhibit the growth of bacteria Eschierchia coli, Pseudomonas and Salmonella was investigated. Using the diffusimetric method there were measured the diameters of inhibition, in order to classify the sensitivity of gram negative bacteria to oxide compounds containing silver, for their use as filters. Vitreous samples were processed as powders with grain between 45 and 75 m and less than 45 m for a large of contact area with the microorgansms and to make possible the study of biological effect of grain addiction. Action of the investigated oxide system against the gram negative bacteria is strictly related to the presence of silver oxide in glass composition.

  1. Flow cytometric evaluation of physico-chemical impact on Gram-positive and Gram-negative bacteria

    Science.gov (United States)

    Fröhling, Antje; Schlüter, Oliver

    2015-01-01

    Since heat sensitivity of fruits and vegetables limits the application of thermal inactivation processes, new emerging inactivation technologies have to be established to fulfill the requirements of food safety without affecting the produce quality. The efficiency of inactivation treatments has to be ensured and monitored. Monitoring of inactivation effects is commonly performed using traditional cultivation methods which have the disadvantage of the time span needed to obtain results. The aim of this study was to compare the inactivation effects of peracetic acid (PAA), ozonated water (O3), and cold atmospheric pressure plasma (CAPP) on Gram-positive and Gram-negative bacteria using flow cytometric methods. E. coli cells were completely depolarized after treatment (15 s) with 0.25% PAA at 10°C, and after treatment (10 s) with 3.8 mg l−1 O3 at 12°C. The membrane potential of CAPP treated cells remained almost constant at an operating power of 20 W over a time period of 3 min, and subsequently decreased within 30 s of further treatment. Complete membrane permeabilization was observed after 10 s O3 treatment, but treatment with PAA and CAPP did not completely permeabilize the cells within 2 and 4 min, respectively. Similar results were obtained for esterase activity. O3 inactivates cellular esterase but esterase activity was detected after 4 min CAPP treatment and 2 min PAA treatment. L. innocua cells and P. carotovorum cells were also permeabilized instantaneously by O3 treatment at concentrations of 3.8 ± 1 mg l−1. However, higher membrane permeabilization of L. innocua and P. carotovorum than of E. coli was observed at CAPP treatment of 20 W. The degree of bacterial damage due to the inactivation processes is highly dependent on treatment parameters as well as on treated bacteria. Important information regarding the inactivation mechanisms can be obtained by flow cytometric measurements and this enables the definition of critical process parameters. PMID

  2. Flow cytometric evaluation of physico-chemical impact on Gram-positive and Gram-negative bacteria

    Directory of Open Access Journals (Sweden)

    Antje eFröhling

    2015-09-01

    Full Text Available Since heat sensitivity of fruits and vegetables limits the application of thermal inactivation processes, new emerging inactivation technologies have to be established to fulfil the requirements of food safety without affecting the produce quality. The efficiency of inactivation treatments has to be ensured and monitored. Monitoring of inactivation effects is commonly performed using traditional cultivation methods which have the disadvantage of the time span needed to obtain results.The aim of this study was to compare the inactivation effects of peracetic acid (PAA, ozonated water (O3 and cold atmospheric pressure plasma (CAPP on Gram-positive and Gram-negative bacteria using flow cytometric methods. E. coli cells were completely depolarized after treatment (15 s with 0.25 % PAA at 10 °C, and after treatment (10 s with 3.8 mg l-1 O3 at 12°C. The membrane potential of CAPP treated cells remained almost constant at an operating power of 20 W over a time period of 3 min, and subsequently decreased within 30 s of further treatment. Complete membrane permeabilization was observed after 10 s O3 treatment, but treatment with PAA and CAPP did not completely permeabilize the cells within 2 min and 4 min, respectively. Similar results were obtained for esterase activity. O3 inactivates cellular esterase but esterase activity was detected after 4 min CAPP treatment and 2 min PAA treatment. L. innocua cells and P. carotovorum cells were also permeabilized instantaneously by O3 treatment at concentrations of 3.8 ± 1 mg l-1. However, higher membrane permeabilization of L. innocua and P. carotovorum than of E. coli was observed at CAPP treatment of 20 W. The degree of bacterial damage due to the inactivation processes is highly dependent on treatment parameters as well as on treated bacteria. Important information regarding the inactivation mechanisms can be obtained by flow cytometric measurements and this enables the definition of critical process

  3. Antibacterial properties of biosurfactants against selected Gram-positive and -negative bacteria.

    Science.gov (United States)

    Díaz De Rienzo, Mayri A; Stevenson, Paul; Marchant, Roger; Banat, Ibrahim M

    2016-01-01

    The antibacterial properties and ability to disrupt biofilms of biosurfactants (rhamnolipids, sophorolipids) and sodium dodecyl sulphate (SDS) in the presence and absence of selected organic acids were investigated. Pseudomonas aeruginosa PAO1 was inhibited by sophorolipids and SDS at concentrations >5% v/v, and the growth of Escherichia coli NCTC 10418 was also inhibited by sophorolipids and SDS at concentrations >5% and 0.1% v/v, respectively. Bacillus subtilis NCTC 10400 was inhibited by rhamnolipids, sophorolipids and SDS at concentrations >0.5% v/v of all three; the same effect was observed with Staphylococcus aureus ATCC 9144. The ability to attach to surfaces and biofilm formation of P. aeruginosa PAO1, E. coli NCTC 10418 and B. subtilis NCTC 10400 was inhibited by sophorolipids (1% v/v) in the presence of caprylic acid (0.8% v/v). In the case of S. aureus ATCC 9144, the best results were obtained using caprylic acid on its own. It was concluded that sophorolipids are promising compounds for the inhibition/disruption of biofilms formed by Gram-positive and Gram-negative microorganisms and this activity can be enhanced by the presence of booster compounds such as caprylic acid. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. Benzyl isothiocyanate, a major component from the roots of Salvadora persica is highly active against Gram-negative bacteria.

    Directory of Open Access Journals (Sweden)

    Abier Sofrata

    Full Text Available Plants produce a number of antimicrobial substances and the roots of the shrub Salvadora persica have been demonstrated to possess antimicrobial activity. Sticks from the roots of S. persica, Miswak sticks, have been used for centuries as a traditional method of cleaning teeth. Diverging reports on the chemical nature and antimicrobial repertoire of the chewing sticks from S. persica led us to explore its antibacterial properties against a panel of pathogenic or commensal bacteria and to identify the antibacterial component/s by methodical chemical characterization. S. persica root essential oil was prepared by steam distillation and solid-phase microextraction was used to sample volatiles released from fresh root. The active compound was identified by gas chromatography-mass spectrometry and antibacterial assays. The antibacterial compound was isolated using medium-pressure liquid chromatography. Transmission electron microscopy was used to visualize the effect on bacterial cells. The main antibacterial component of both S. persica root extracts and volatiles was benzyl isothiocyanate. Root extracts as well as commercial synthetic benzyl isothiocyanate exhibited rapid and strong bactericidal effect against oral pathogens involved in periodontal disease as well as against other Gram-negative bacteria, while Gram-positive bacteria mainly displayed growth inhibition or remained unaffected. The short exposure needed to obtain bactericidal effect implies that the chewing sticks and the essential oil may have a specific role in treatment of periodontal disease in reducing Gram-negative periodontal pathogens. Our results indicate the need for further investigation into the mechanism of the specific killing of Gram-negative bacteria by S. persica root stick extracts and its active component benzyl isothiocyanate.

  5. Pulmonary melioidosis presenting with pleural effusion: A case report and review of literature

    Directory of Open Access Journals (Sweden)

    Chun Ian Soo

    2015-01-01

    Full Text Available Melioidosis is a serious infection, which can involve multiple systems. We report a case of pulmonary melioidosis with the initial presentation mimicking a partially treated pneumonia complicated by right-sided pleural effusion. The patient is a 49-year old man who did not respond to parenteral ceftriaxone and tazobactam/piperacillin therapy. However, upon culture and sensitivity results from blood and pleural samples isolated Burkholderia pseudomallei; antimicrobial therapy was de-escalated to parenteral ceftazidime. Within 72 h duration, his fever subsided and other respiratory symptoms improved tremendously. This case highlights the importance of early recognition of B. pseudomallei in pulmonary infection in order for prompt institution of appropriate antibiotics treatment; thus reducing morbidity and mortality.

  6. High Prevalence of Antimicrobial-resistant Gram-negative Colonization in Hospitalized Cambodian Infants.

    Science.gov (United States)

    Turner, Paul; Pol, Sreymom; Soeng, Sona; Sar, Poda; Neou, Leakhena; Chea, Phal; Day, Nicholas Pj; Cooper, Ben S; Turner, Claudia

    2016-08-01

    Antimicrobial-resistant Gram-negative infections are a significant cause of mortality in young infants. We aimed to determine characteristics of, and risk factors for, colonization and invasive infection caused by 3rd generation cephalosporin (3GC) or carbapenem-resistant organisms in outborn infants admitted to a neonatal unit (NU) in Cambodia. During the first year of operation, patients admitted to the Angkor Hospital for Children NU, Siem Reap, Cambodia, underwent rectal swabbing on admission and twice weekly until discharge. Swabs were taken also from 7 environmental sites. Swabs were cultured to identify 3GC or carbapenem-resistant Acinetobacter sp., Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa. The study included 333 infants with a median age at NU admission of 10 days (range, 0-43). Colonization by ≥1 3GC-resistant organism was detected in 85.9% (286/333). Admission swabs were collected in 289 infants: 61.9% were colonized by a 3GC-resistant organism at the time of admission, and a further 23.2% were colonized during hospitalization, at a median of 4 days [95% confidence interval: 3-5]. Probiotic treatment (hazard ratio: 0.58; 95% confidence interval: 0.35-0.98) was associated with delayed colonization. Colonization by a carbapenem-resistant organism occurred in 25 (7.5%) infants. Six infants had NU-associated K. pneumoniae bacteremia; phenotypically identical colonizing strains were found in 3 infants. Environmental colonization occurred early. Colonization by antimicrobial-resistant Gram-negative organisms occurred early in hospitalized Cambodian infants and was associated with subsequent invasive infection. Trials of potential interventions such as probiotics are needed.

  7. Multidrug-resistant Gram-negative bacteria: a product of globalization.

    Science.gov (United States)

    Hawkey, P M

    2015-04-01

    Global trade and mobility of people has increased rapidly over the last 20 years. This has had profound consequences for the evolution and the movement of antibiotic resistance genes. There is increasing exposure of populations all around the world to resistant bacteria arising in the emerging economies. Arguably the most important development of the last two decades in the field of antibiotic resistance is the emergence and spread of extended-spectrum β-lactamases (ESBLs) of the CTX-M group. A consequence of the very high rates of ESBL production among Enterobacteriaceae in Asian countries is that there is a substantial use of carbapenem antibiotics, resulting in the emergence of plasmid-mediated resistance to carbapenems. This article reviews the emergence and spread of multidrug-resistant Gram-negative bacteria, focuses on three particular carbapenemases--imipenem carbapenemases, Klebsiella pneumoniae carbapenemase, and New Delhi metallo-β-lactamase--and highlights the importance of control of antibiotic use. Copyright © 2015. Published by Elsevier Ltd.

  8. A randomized clinical trial on the effectiveness of a symbiotic product to decolonize patients harboring multidrug-resistant Gram-negative bacilli

    Directory of Open Access Journals (Sweden)

    Mariana Correa Coelho Salomão

    Full Text Available Abstract INTRODUCTION: We aimed to evaluate the effectiveness of a symbiotic product to decolonize the intestinal tract of patients harboring multidrug-resistant (MDR Gram-negative bacilli and to prevent nosocomial infections. METHODS: This was a randomized, double blind, placebo-controlled clinical trial, conducted in a tertiary-care university hospital. All adult hospitalized patients with a positive clinical culture and a positive rectal swab for any MDR Gram-negative bacilli were potentially eligible. Exclusion criteria were pregnancy, immunosuppression, and bowel obstruction/perforation. The intervention consisted of administering a symbiotic product (Lactobacillus bulgaricus, Lactobacillus rhamnosus, and fructo-oligosaccharides twice a day for seven days via the oral/enteral route. RESULTS: Between August 1, 2012 and December 22, 2013, 116 of 275 eligible patients were allocated to treatment (n=57 and placebo (n=59. Overall, 101 patients received at least four doses of the study products and were included in the modified intention-to-treat analysis. The primary study outcome, a negative rectal swab for MDR Gram-negative bacilli after treatment, was identified in 16.7% (8/48 and 20.7% (11/53 of patients in the experimental and placebo group, respectively (p=0.60. The secondary outcome, the combined incidence of nosocomial respiratory and urinary tract infections, was 37.5% (18/48 in the experimental group versus 22.6% (12/53 in the control group (adjusted odds ratio: 1.95, 95% confidence interval: 0.69-5.50, p=0.21. Length of stay after the beginning of the intervention, incidence of adverse events, and in-hospital mortality rates were similar in both study groups. CONCLUSIONS: Under the present study conditions, symbiotic administration was not effective for decolonizing hospitalized patients harboring MDR Gram-negative bacilli.

  9. Defining Multidrug Resistance of Gram-Negative Bacteria in the Dutch-German Border Region-Impact of National Guidelines

    NARCIS (Netherlands)

    Köck, Robin; Siemer, Philipp; Esser, Jutta; Kampmeier, Stefanie; Berends, Matthijs S; Glasner, Corinna; Arends, Jan P; Becker, Karsten; Friedrich, Alexander W

    2018-01-01

    Preventing the spread of multidrug-resistant Gram-negative bacteria (MDRGNB) is a public health priority. However, the definition of MDRGNB applied for planning infection prevention measures such as barrier precautions differs depending on national guidelines. This is particularly relevant in the

  10. Effect of Light-Activated Hypocrellin B on the Growth and Membrane Permeability of Gram-Negative Escherichia coli Cells

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    Yuan Jiang

    2014-01-01

    Full Text Available Aim. To investigate the effect of light-activated hypocrellin B on the growth and membrane permeability of Gram-negative bacteria. Methods. Escherichia coli (E. coli as a model bacterium of Gram-negative bacteria was incubated with various concentrations of hypocrellin B for 60 min and was subsequently irradiated by blue light with wavelength of 470 nm at the dose of 12 J/cm2. Colony forming units were counted and the growth inhibition rate of E. coli cells was calculated after light-activated hypocrellin B. Membrane permeability was measured using flow cytometry and confocal laser scanning microscopy (CLSM with propidium iodide (PI staining. Bacterial morphology was observed using transmission electron microscopy (TEM. Reactive oxygen species in bacterial cells were measured using flow cytometry with DCFH-DA staining. Results. Significant growth inhibition rate of E. coli cells was observed after photodynamic action of hypocrellin B. Remarkable damage to the ultrastructure of E. coli was also observed by TEM. Flow cytometry and CLSM observation showed that light-activated hypocrellin B markedly increased membrane permeability of E. coli. Flow cytometry showed the intracellular ROS increase in E. coli treated by photodynamic action of hypocrellin B. Conclusion. Light-activated hypocrellin B caused intracellular ROS increase and structural damages and inhibited the growth of Gram-negative E. coli cells.

  11. Fastidious Gram-Negatives: Identification by the Vitek 2 Neisseria-Haemophilus Card and by Partial 16S rRNA Gene Sequencing Analysis

    DEFF Research Database (Denmark)

    Wolff Sönksen, Ute; Christensen, Jens Jørgen; Nielsen, Lisbeth

    2010-01-01

    Taxonomy and identification of fastidious Gram negatives are evolving and challenging. We compared identifications achieved with the Vitek 2 Neisseria-Haemophilus (NH) card and partial 16S rRNA gene sequence (526 bp stretch) analysis with identifications obtained with extensive phenotypic...... characterization using 100 fastidious Gram negative bacteria. Seventy-five strains represented 21 of the 26 taxa included in the Vitek 2 NH database and 25 strains represented related species not included in the database. Of the 100 strains, 31 were the type strains of the species. Vitek 2 NH identification...

  12. Indium 111 leucocyte scintigraphy in abdominal sepsis

    International Nuclear Information System (INIS)

    Baba, A.A.; McKillop, J.H.; Gray, H.W.; Cuthbert, G.F.; Neilson, W.; Anderson, J.R.

    1990-01-01

    We have studied the clinical utility of indium 111 autologous leucocyte scintigraphy retrospectively in 45 patients presenting with suspected intra-abdominal sepsis. The sensitivity was 95% (21/22) and the specificity was 91% (21/23). Some 34 of the studies (17 positive and 17 negative) were considered helpful in furthering patient management (76%) and 8, unhelpful (18%). In 3, the study results were misleading and led to inappropriate treatment. Indium 111 scintigraphy, whether positive or negative, provides information in patients with suspected intra-abdominal sepsis upon which therapeutic decisions can be based. (orig.)

  13. A new technique for Gram staining paraffin-embedded tissue.

    Science.gov (United States)

    Engbaek, K; Johansen, K S; Jensen, M E

    1979-01-01

    Five techniques for Gram staining bacteria in paraffin sections were compared on serial sections of pulmonary tissues from eight bacteriological necropsies. Brown and Hopp's method was the most satisfactory for distinguishing Gram-positive and Gram-negative bacteria. However, this method cannot be recommended as the preparations were frequently overstained, and the Gram-negative bacteria were stained indistinctly. A modification of Brown and Hopps' method was developed which stains larger numbers of Gram-negative bacteria and differentiates well between different cell types and connective tissue, and there is no risk of overstaining. PMID:86548

  14. Phylogenomic Analysis Reveals an Asian Origin for African Burkholderia pseudomallei and Further Supports Melioidosis Endemicity in Africa.

    Science.gov (United States)

    Sarovich, Derek S; Garin, Benoit; De Smet, Birgit; Kaestli, Mirjam; Mayo, Mark; Vandamme, Peter; Jacobs, Jan; Lompo, Palpouguini; Tahita, Marc C; Tinto, Halidou; Djaomalaza, Innocente; Currie, Bart J; Price, Erin P

    2016-01-01

    Burkholderia pseudomallei, an environmental bacterium that causes the deadly disease melioidosis, is endemic in northern Australia and Southeast Asia. An increasing number of melioidosis cases are being reported in other tropical regions, including Africa and the Indian Ocean islands. B. pseudomallei first emerged in Australia, with subsequent rare dissemination event(s) to Southeast Asia; however, its dispersal to other regions is not yet well understood. We used large-scale comparative genomics to investigate the origins of three B. pseudomallei isolates from Madagascar and two from Burkina Faso. Phylogenomic reconstruction demonstrates that these African B. pseudomallei isolates group into a single novel clade that resides within the more ancestral Asian clade. Intriguingly, South American strains reside within the African clade, suggesting more recent dissemination from West Africa to the Americas. Anthropogenic factors likely assisted in B. pseudomallei dissemination to Africa, possibly during migration of the Austronesian peoples from Indonesian Borneo to Madagascar ~2,000 years ago, with subsequent genetic diversity driven by mutation and recombination. Our study provides new insights into global patterns of B. pseudomallei dissemination and adds to the growing body of evidence of melioidosis endemicity in Africa. Our findings have important implications for melioidosis diagnosis and management in Africa. IMPORTANCE Sporadic melioidosis cases have been reported in the African mainland and Indian Ocean islands, but until recently, these regions were not considered areas where B. pseudomallei is endemic. Given the high mortality rate of melioidosis, it is crucial that this disease be recognized and suspected in all regions of endemicity. Previous work has shown that B. pseudomallei originated in Australia, with subsequent introduction into Asia; however, the precise origin of B. pseudomallei in other tropical regions remains poorly understood. Using

  15. Computed tomography characteristics of hepatic and splenic abscesses associated with melioidosis: a 7- year study

    International Nuclear Information System (INIS)

    Apisarnthanarak, Piyaporn; Thairatananon, Atita; Muangsomboon, Kobkum

    2011-01-01

    Full text: This study aimed to characterise the CT findings associated with hepatic and splenic melioid abscesses. Patients with CT evidence of hepatic and/or splenic abscesses were retrospectively evaluated for clinical evidence of melioidosis over a 7-year period. After blinded review of the CT characteristics of intra-abdominal abscesses (IAA), we conducted a stratified analysis of patients with and without melioid IAA. Among 49 patients with CT evidence of hepatic and/or splenic IAA, the mean age was 50.2 years, 22 (44.9%) were women and eight (16.3%) had laboratory confirmation of melioidosis. For the 113 IAA, 33 were melioid abscesses (15 liver and 18 spleen) and 80 were non-melioid abscesses (69 liver and 11 spleen). Splenic IAA were more common in the melioid group (P = 0.001) and smaller in diameter than the hepatic IAA (P < 0.001). Melioid IAA were smaller than non-melioid IAA (P < 0.001) and the CT necklace sign was the strongest predictor for melioid IAA (odds ratio = 24.6, P = 0.006) with 100% specificity. Other significant predictors for melioidosis were concurrent hepatic and splenic involvement (P = 0.009), multiple abscesses (P = 0.015) and residence in an endemic area (P = 0.047). By multivariate analysis, concurrent hepatic and splenic involvement was the sole predictor of melioi dosis (adjusted odds ratio = 11.3, 95% confidence interval = 1.6-77.5, P = 0.014). The CT necklace sign, along with concurrent hepatic and splenic IAA, were highly suggestive of melioidosis in persons from Central Thailand.

  16. The warmer the weather, the more gram-negative bacteria - impact of temperature on clinical isolates in intensive care units.

    Directory of Open Access Journals (Sweden)

    Frank Schwab

    Full Text Available BACKGROUND: We investigated the relationship between average monthly temperature and the most common clinical pathogens causing infections in intensive care patients. METHODS: A prospective unit-based study in 73 German intensive care units located in 41 different hospitals and 31 different cities with total 188,949 pathogen isolates (102,377 Gram-positives and 86,572 Gram-negatives from 2001 to 2012. We estimated the relationship between the number of clinical pathogens per month and the average temperature in the month of isolation and in the month prior to isolation while adjusting for confounders and long-term trends using time series analysis. Adjusted incidence rate ratios for temperature parameters were estimated based on generalized estimating equation models which account for clustering effects. RESULTS: The incidence density of Gram-negative pathogens was 15% (IRR 1.15, 95%CI 1.10-1.21 higher at temperatures ≥ 20°C than at temperatures below 5°C. E. cloacae occurred 43% (IRR=1.43; 95%CI 1.31-1.56 more frequently at high temperatures, A. baumannii 37% (IRR=1.37; 95%CI 1.11-1.69, S. maltophilia 32% (IRR=1.32; 95%CI 1.12-1.57, K. pneumoniae 26% (IRR=1.26; 95%CI 1.13-1.39, Citrobacter spp. 19% (IRR=1.19; 95%CI 0.99-1.44 and coagulase-negative staphylococci 13% (IRR=1.13; 95%CI 1.04-1.22. By contrast, S. pneumoniae 35% (IRR=0.65; 95%CI 0.50-0.84 less frequently isolated at high temperatures. For each 5°C increase, we observed a 3% (IRR=1.03; 95%CI 1.02-1.04 increase of Gram-negative pathogens. This increase was highest for A. baumannii with 8% (IRR=1.08; 95%CI 1.05-1.12 followed by K. pneumoniae, Citrobacter spp. and E. cloacae with 7%. CONCLUSION: Clinical pathogens vary by incidence density with temperature. Significant higher incidence densities of Gram-negative pathogens were observed during summer whereas S. pneumoniae peaked in winter. There is increasing evidence that different seasonality due to physiologic changes underlies

  17. MALDI-TOF identification of Gram-negative bacteria directly from blood culture bottles containing charcoal: Sepsityper® kits versus centrifugation-filtration method.

    Science.gov (United States)

    Riederer, Kathleen; Cruz, Kristian; Shemes, Stephen; Szpunar, Susan; Fishbain, Joel T

    2015-06-01

    Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry has dramatically altered the way microbiology laboratories identify clinical isolates. Direct blood culture (BC) detection may be hampered, however, by the presence of charcoal in BC bottles currently in clinical use. This study evaluates an in-house process for extraction and MALDI-TOF identification of Gram-negative bacteria directly from BC bottles containing charcoal. Three hundred BC aliquots were extracted by a centrifugation-filtration method developed in our research laboratory with the first 96 samples processed in parallel using Sepsityper® kits. Controls were colonies from solid media with standard phenotypic and MALDI-TOF identification. The identification of Gram-negative bacteria was successful more often via the in-house method compared to Sepsityper® kits (94.7% versus 78.1%, P≤0.0001). Our in-house centrifugation-filtration method was further validated for isolation and identification of Gram-negative bacteria (95%; n=300) directly from BC bottles containing charcoal. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Associations of Eu(III) with Gram-negative bacteria, Alcaligenes faecalis, Shewanella putrefaciens, and Paracoccus denitrificans

    International Nuclear Information System (INIS)

    Ozaki, Takuo; Ohnuki, Toshihiko; Kimura, Takaumi; Francis, Arokiasamy J.

    2005-01-01

    We studied the association of Eu(III) with Gram-negative bacteria, Alcaligenes faecalis, Shewanella putrefaciens, and Paracoccus denitrificans by a batch method and time-resolved laser-induced fluorescence spectroscopy (TRLFS). The kinetics study showed that the Eu(III) adsorption on the bacteria rapidly proceeded. The Eu(III) adsorption on A. faecalis and P. denitrificans at pHs 3, 4, and 5, and that on S.putrefaciens at pHs 4 and 5 reached a maximum within 5 minutes after contact. For P. denitrificans, the percent adsorption of Eu(III) decreased after the maximum percent adsorption was attained, which suggests the existence of exudates with an affinity with Eu(III). TRLFS showed that the coordination of Eu(III) on these bacteria is multidentate through an inner-spherical process. The ligand field of Eu(III) on P. denitrificans was as strong as the ones observed for halophilic microorganisms, while that of A. faecalis and S. putrefaciens was the typical one observed for non-halophilic microorganisms. The coordination environment of Eu(III) on the bacteria differed from each other, though they are categorized as Gram-negative bacteria with the similar cell wall components. (author)

  19. Super-Resolution Imaging of Protein Secretion Systems and the Cell Surface of Gram-Negative Bacteria

    Directory of Open Access Journals (Sweden)

    Sachith D. Gunasinghe

    2017-05-01

    Full Text Available Gram-negative bacteria have a highly evolved cell wall with two membranes composed of complex arrays of integral and peripheral proteins, as well as phospholipids and glycolipids. In order to sense changes in, respond to, and exploit their environmental niches, bacteria rely on structures assembled into or onto the outer membrane. Protein secretion across the cell wall is a key process in virulence and other fundamental aspects of bacterial cell biology. The final stage of protein secretion in Gram-negative bacteria, translocation across the outer membrane, is energetically challenging so sophisticated nanomachines have evolved to meet this challenge. Advances in fluorescence microscopy now allow for the direct visualization of the protein secretion process, detailing the dynamics of (i outer membrane biogenesis and the assembly of protein secretion systems into the outer membrane, (ii the spatial distribution of these and other membrane proteins on the bacterial cell surface, and (iii translocation of effector proteins, toxins and enzymes by these protein secretion systems. Here we review the frontier research imaging the process of secretion, particularly new studies that are applying various modes of super-resolution microscopy.

  20. Monomicrobial necrotizing fasciitis in a single center: the emergence of Gram-negative bacteria as a common pathogen

    Directory of Open Access Journals (Sweden)

    D. Yahav

    2014-11-01

    Conclusions: In our center, 42% of monomicrobial necrotizing fasciitis cases were found to be caused by Gram-negative organisms, mostly E. coli. These infections usually appeared in immunocompromised or postoperative patients, often presented with normal CPK levels, and were associated with high mortality rates.

  1. Viruses and Gram-negative bacilli dominate the etiology of community-acquired pneumonia in Indonesia, a cohort study

    Directory of Open Access Journals (Sweden)

    Helmia Farida

    2015-09-01

    Conclusions: Viruses and Gram-negative bacilli are dominant causes of CAP in this region, more so than S. pneumoniae. Most of the bacteria have wild type susceptibility to antimicrobial agents. Patients with severe disease and those with unknown etiology have a higher mortality risk.

  2. Antimicrobial Activity of Ephedra pachyclada Methanol Extract on Some Enteric Gram Negative Bacteria Which Causes Nosocomial Infections by Agar Dilution Method

    Directory of Open Access Journals (Sweden)

    Amin Sadeghi Dosari

    2016-10-01

    Full Text Available Background Past history indicates that plants were served as an important source of medicine. Otherwise, in developing countries people use medicinal plants against infectious disease because they cannot afford expensive drugs. Due to increasing rate of drug-resistant diseases, there is an urgent need to detect novel antimicrobial compounds from medicinal plants. Objectives The aim of the present study was to determine Antimicrobial activity of Ephedra pachyclada methanol extract on some enteric Gram-negative bacteria which causes nosocomial infections by agar dilution method. Methods In this cross-sectional study, in order to examine the antimicrobial effects of Ephedra pachyclada extract on intestinal Gram-negative bacteria, we exposed them to 0/128, 0/25, 0/5, 1, 2, 4 and 8 mg/mL of the extract. Ephedra pachyclada was collected from Jiroft Heights and methanolic extract was prepared with maceration method, during which, 50 gr powder of Ephedra pachyclada was dissolved in 300 mL of 80% methanol. Results In this study, the antibacterial effects of Ephedra pachyclada extract on Gram-negative bacteria such as Pseudomonas aeruginosa, Escherichia coli (PTCC-O157, Escherichia coli (ATCC-25922, Klebsiella pnemoniae, Serratia marcescens was investigated, defining the minimum inhibitory concentration (MIC by agar dilution method. It has been demonstrated that methanolic extract of Ephedra pachyclada affect intestinal Gram-negative bacteria. Conclusions The result showed that, Ephedra pachyclada extract has effective antimicrobial ingredients which are cheap and readily available. It can be used for medicinal purposes in the production of antimicrobial drug.

  3. Screening of the novel colicinogenic gram-negative rods against pathogenic Escherichia coli O157:H7

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    H Mushtaq

    2015-01-01

    Full Text Available Purpose: Escherichia coli (E. coli O157:H7 is gram-negative enteric pathogen producing different types of Shiga toxin. This bacterium is the most corporate cause of haemorrhagic colitis in human. Administration of antibiotics (particularly sulfa drugs against this pathogen is a debatable topic as this may increase the risk of uremic syndrome; especially in children and aged people. Around the world, microbiologists are in search of alternative therapeutic methods specially probiotics against this pathogen. In the present study, we have focused on the investigation of alternate bio-therapeutics (probiotics for the treatment of patients infected with E. coli O157:H7. This study is based on the identification of colicin-producing gram-negative bacteria (particularly enterobacteriaceae which can competently exclude E. coli O157:H7 from the gut of the infected individual. Materials and Methods: Hundred samples from human, animal faeces and septic tank water were analysed for nonpathogenic gram-negative rods (GNRs. Results: Out of these samples, 175 isolates of GNRs were checked for their activity against E. coli O157:H7. Only 47 isolates inhibited the growth of E. coli O157:H7, among which majority were identified as E. coli. These E. coli strains were found to be the efficient producers of colicin. Some of the closely related species i. e., Citrobacter sp, Pantoea sp. and Kluyvera sp. also showed considerable colicinogenic activity. Moreover, colicinogenic species were found to be nonhaemolytic, tolerant to acidic environment (pH 3 and sensitive to commonly used antibiotics. Conclusion: Nonhaemolytic, acid tolerant and sensitive to antibiotics suggests the possible use of these circulating endothelial cells (CEC as inexpensive and inoffensive therapeutic agent (probiotics in E. coli O157:H7 infections.

  4. Complete Genome Sequence of Bacillus velezensis CN026 Exhibiting Antagonistic Activity against Gram-Negative Foodborne Pathogens

    OpenAIRE

    Nannan, Catherine; Gillis, Annika; Caulier, Simon; Mahillon, Jacques

    2018-01-01

    ABSTRACT We report here the complete genome sequence of Bacillus velezensis strain CN026, a member of the B. subtilis group, which is known for its many industrial applications. The genome contains 3,995,812 bp and displays six gene clusters potentially involved in strain CN026’s activity against Gram-negative foodborne pathogens.

  5. Using BOX-PCR to exclude a clonal outbreak of melioidosis

    Directory of Open Access Journals (Sweden)

    Ward Linda

    2007-06-01

    Full Text Available Abstract Background Although melioidosis in endemic regions is usually caused by a diverse range of Burkholderia pseudomallei strains, clonal outbreaks from contaminated potable water have been described. Furthermore B. pseudomallei is classified as a CDC Group B bioterrorism agent. Ribotyping, pulsed-field gel electrophoresis (PFGE and multilocus sequence typing (MLST have been used to identify genetically related B. pseudomallei isolates, but they are time consuming and technically challenging for many laboratories. Methods We have adapted repetitive sequence typing using a BOX A1R primer for typing B. pseudomallei and compared BOX-PCR fingerprinting results on a wide range of well-characterized B. pseudomallei isolates with MLST and PFGE performed on the same isolates. Results BOX-PCR typing compared favourably with MLST and PFGE performed on the same isolates, both discriminating between the majority of multilocus sequence types and showing relatedness between epidemiologically linked isolates from various outbreak clusters. Conclusion Our results suggest that BOX-PCR can be used to exclude a clonal outbreak of melioidosis within 10 hours of receiving the bacterial strains.

  6. Identification of gram-negative bacteria from critical control points of raw and pasteurized cow milk consumed at Gondar town and its suburbs, Ethiopia.

    Science.gov (United States)

    Garedew, Legesse; Berhanu, Ayalew; Mengesha, Desalegne; Tsegay, Getachew

    2012-11-06

    Milk is highly prone to contamination and can serve as an efficient vehicle for human transmission of foodborne pathogens, especially gram-negative bacteria, as these are widely distributed in the environment. This cross-sectional study of gram-negative staining bacterial contamination of milk meant for human consumption was carried out from October 2010 to May 2011 in Gondar town, Ethiopia. Milk samples were collected from critical control points, from production to consumption, that were hypothesized to be a source of potential contamination. Milk sampling points included smallholder's milk producers, dairy co-operatives, a milk processing plant, and supermarkets. The hygienic procedures applied during milking, milk collection, transportation, pasteurization, and postpasteurization storage conditions at these specified critical control points were evaluated. Standard bacteriological cultivation and biochemical assays were used to isolate and identify bacterial pathogens in the milk samples. The results of the current study showed that conditions for contamination of raw milk at different critical points were due to less hygienic practices in pre-milking udder preparation, sub-optimal hygiene of milk handlers, and poor sanitation practices associated with milking and storage equipments. Among all critical control points considered, transportation containers at milk collection centers and at processing plants were found to be the most heavily contaminated with gram-negative staining bacterial species. Overall, 54 different bacterial species were indentified, and Escherichia coli (29.6%), Pseudomonas aeruginosa (18.5%), and Klebsiella pneumoniae (16.7%), were the most commonly identified gram-negative staining bacterial pathogens. Of particular interest was that no gram-negative staining bacteria were isolated from pasteurized milk samples with varying shelf life. This study showed the presence of diverse pathogenic gram-negative staining bacterial species in raw

  7. Identification of gram-negative bacteria from critical control points of raw and pasteurized cow milk consumed at Gondar town and its suburbs, Ethiopia

    Directory of Open Access Journals (Sweden)

    Garedew Legesse

    2012-11-01

    Full Text Available Abstract Background Milk is highly prone to contamination and can serve as an efficient vehicle for human transmission of foodborne pathogens, especially gram-negative bacteria, as these are widely distributed in the environment. Methods This cross-sectional study of gram-negative staining bacterial contamination of milk meant for human consumption was carried out from October 2010 to May 2011 in Gondar town, Ethiopia. Milk samples were collected from critical control points, from production to consumption, that were hypothesized to be a source of potential contamination. Milk sampling points included smallholder’s milk producers, dairy co-operatives, a milk processing plant, and supermarkets. The hygienic procedures applied during milking, milk collection, transportation, pasteurization, and postpasteurization storage conditions at these specified critical control points were evaluated. Standard bacteriological cultivation and biochemical assays were used to isolate and identify bacterial pathogens in the milk samples. Results The results of the current study showed that conditions for contamination of raw milk at different critical points were due to less hygienic practices in pre-milking udder preparation, sub-optimal hygiene of milk handlers, and poor sanitation practices associated with milking and storage equipments. Among all critical control points considered, transportation containers at milk collection centers and at processing plants were found to be the most heavily contaminated with gram-negative staining bacterial species. Overall, 54 different bacterial species were indentified, and Escherichia coli (29.6%, Pseudomonas aeruginosa (18.5%, and Klebsiella pneumoniae (16.7%, were the most commonly identified gram-negative staining bacterial pathogens. Of particular interest was that no gram-negative staining bacteria were isolated from pasteurized milk samples with varying shelf life. Conclusion This study showed the presence of

  8. Combined physico-chemical treatments based on enterocin AS-48 for inactivation of Gram-negative bacteria in soybean sprouts.

    Science.gov (United States)

    Cobo Molinos, Antonio; Abriouel, Hikmate; López, Rosario Lucas; Valdivia, Eva; Omar, Nabil Ben; Gálvez, Antonio

    2008-08-01

    Enterocin AS-48 was tested for decontamination of soybean sprouts against Gram-negative bacteria. Although treatment with bacteriocin alone had no effect on Salmonella enterica, a synergistic antimicrobial effect was detected at pH 9.0 and in combination with moderate heat treatment. Greatest inactivation was achieved for sprouts heated for 5 min at 65 degrees C in an alkaline (pH 9.0) enterocin AS-48 solution of 25 microg/ml. Bactericidal activity against S. enterica increased greatly when enterocin AS-48 was used in washing solutions in combination with several chemical compounds: EDTA, lactic acid, peracetic acid, polyphosphoric acid, sodium hypochlorite, hexadecylpyridinium chloride, propyl-p-hydroxybenzoate, and hydrocinnamic acid. The combined treatment of enterocin AS-48 and polyphosphoric acid was tested against several other Gram-negative bacteria inoculated on sprouts. The bacteria tested showed great differences in sensitivity to polyphosphoric acid, but synergism with enterocin AS-48 was confirmed in all cases. Combinations of enterocin AS-48 (25 microg/ml) and polyphosphoric acid in a concentration range of 0.1 to 2.0% significantly reduced or inhibited growth of the populations of S. enterica, Escherichia coli O157:H7, Shigella spp., Enterobacter aerogenes, Yersinia enterocolitica, Aeromonas hydrophila and Pseudomonas fluorescens in sprout samples stored at 6 degrees C and 15 degrees C. The combined treatment could therefore be applied to reduce the risks of Gram-negative pathogenic as well as spoilage bacteria on sprouts.

  9. Complete Genome Sequence of Bacillus velezensis CN026 Exhibiting Antagonistic Activity against Gram-Negative Foodborne Pathogens.

    Science.gov (United States)

    Nannan, Catherine; Gillis, Annika; Caulier, Simon; Mahillon, Jacques

    2018-01-25

    We report here the complete genome sequence of Bacillus velezensis strain CN026, a member of the B. subtilis group, which is known for its many industrial applications. The genome contains 3,995,812 bp and displays six gene clusters potentially involved in strain CN026's activity against Gram-negative foodborne pathogens. Copyright © 2018 Nannan et al.

  10. NEONATAL SEPTICAEMIA IN LOW BIRTH WEIGHT INFANTS AT ...

    African Journals Online (AJOL)

    2005-03-03

    Mar 3, 2005 ... Conclusion: Case fatality rate for low birth weight infants with sepsis is high. Gram negative organisms ... streptococci was found while there was no candida sepsis. Early onset ..... puerperal sepsis study group. Central Afr. J.

  11. Inactivation dynamics of 222 nm krypton-chlorine excilamp irradiation on Gram-positive and Gram-negative foodborne pathogenic bacteria.

    Science.gov (United States)

    Kang, Jun-Won; Kim, Sang-Soon; Kang, Dong-Hyun

    2018-07-01

    The object of this study was to elucidate the bactericidal mechanism of a 222 nm Krypton Chlorine (KrCl) excilamp compared with that of a 254 nm Low Pressure mercury (LP Hg) lamp. The KrCl excilamp had higher bactericidal capacity against Gram-positive pathogenic bacteria (Staphylococcus aureus and L. monocytogenes) and Gram-negative pathogenic bacteria (S. Typhimurium and E. coli O157:H7) than did the LP Hg lamp when cell suspensions in PBS were irradiated with each type of UV lamp. It was found out that the KrCl excilamp induced cell membrane damage as a form of depolarization. From the study of respiratory chain dehydrogenase activity and the lipid peroxidation assay, it was revealed that cell membrane damage was attributed to inactivation of enzymes related to generation of membrane potential and occurrence of lipid peroxidation. Direct absorption of UV radiation which led to photoreaction through formation of an excited state was one of the causes inducing cell damage. Additionally, generation of ROS and thus occurrence of secondary damage can be another cause. The LP Hg lamp only induced damage to DNA but not to other components such as lipids or proteins. This difference was derived from differences of UV radiation absorption by cellular materials. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Evaluation of an expanded microarray for detecting antibiotic resistance genes in a broad range of gram-negative bacterial pathogens.

    Science.gov (United States)

    Card, Roderick; Zhang, Jiancheng; Das, Priya; Cook, Charlotte; Woodford, Neil; Anjum, Muna F

    2013-01-01

    A microarray capable of detecting genes for resistance to 75 clinically relevant antibiotics encompassing 19 different antimicrobial classes was tested on 132 Gram-negative bacteria. Microarray-positive results correlated >91% with antimicrobial resistance phenotypes, assessed using British Society for Antimicrobial Chemotherapy clinical breakpoints; the overall test specificity was >83%. Microarray-positive results without a corresponding resistance phenotype matched 94% with PCR results, indicating accurate detection of genes present in the respective bacteria by microarray when expression was low or absent and, hence, undetectable by susceptibility testing. The low sensitivity and negative predictive values of the microarray results for identifying resistance to some antimicrobial resistance classes are likely due to the limited number of resistance genes present on the current microarray for those antimicrobial agents or to mutation-based resistance mechanisms. With regular updates, this microarray can be used for clinical diagnostics to help accurate therapeutic options to be taken following infection with multiple-antibiotic-resistant Gram-negative bacteria and prevent treatment failure.

  13. Systematic review and consensus guidelines for environmental sampling of Burkholderia pseudomallei.

    Directory of Open Access Journals (Sweden)

    Direk Limmathurotsakul

    Full Text Available Burkholderia pseudomallei, a Tier 1 Select Agent and the cause of melioidosis, is a Gram-negative bacillus present in the environment in many tropical countries. Defining the global pattern of B. pseudomallei distribution underpins efforts to prevent infection, and is dependent upon robust environmental sampling methodology. Our objective was to review the literature on the detection of environmental B. pseudomallei, update the risk map for melioidosis, and propose international consensus guidelines for soil sampling.An international working party (Detection of Environmental Burkholderia pseudomallei Working Party (DEBWorP was formed during the VIth World Melioidosis Congress in 2010. PubMed (January 1912 to December 2011 was searched using the following MeSH terms: pseudomallei or melioidosis. Bibliographies were hand-searched for secondary references. The reported geographical distribution of B. pseudomallei in the environment was mapped and categorized as definite, probable, or possible. The methodology used for detecting environmental B. pseudomallei was extracted and collated. We found that global coverage was patchy, with a lack of studies in many areas where melioidosis is suspected to occur. The sampling strategies and bacterial identification methods used were highly variable, and not all were robust. We developed consensus guidelines with the goals of reducing the probability of false-negative results, and the provision of affordable and 'low-tech' methodology that is applicable in both developed and developing countries.The proposed consensus guidelines provide the basis for the development of an accurate and comprehensive global map of environmental B. pseudomallei.

  14. Antibiotic-induced endotoxin release in patients with gram-negative urosepsis: a double-blind study comparing imipenem and ceftazidime

    NARCIS (Netherlands)

    Prins, J. M.; van Agtmael, M. A.; Kuijper, E. J.; van Deventer, S. J.; Speelman, P.

    1995-01-01

    The clinical significance of differences between antibiotics in endotoxin-liberating potential is unknown. Thirty patients with gram-negative urosepsis were randomized between imipenem and ceftazidime, which have, respectively, a low and a high endotoxin-liberating potential in vitro. In patients

  15. Celecoxib Enhances the Efficacy of Low-Dose Antibiotic Treatment against Polymicrobial Sepsis in Mice and Clinical Isolates of ESKAPE Pathogens.

    Science.gov (United States)

    Annamanedi, Madhavi; Varma, Gajapati Y N; Anuradha, K; Kalle, Arunasree M

    2017-01-01

    Treatment of multidrug resistant bacterial infections has been a great challenge globally. Previous studies including our study have highlighted the use of celecoxib, a non-steroidal anti-inflammatory drug in combination with antibiotic has decreased the minimal inhibitory concentration to limit Staphylococcus aureus infection. However, the efficacy of this combinatorial treatment against various pathogenic bacteria is not determined. Therefore, we have evaluated the potential use of celecoxib in combination with low doses of antibiotic in limiting Gram-positive and Gram-negative bacteria in vivo in murine polymicrobial sepsis developed by cecum ligation and puncture (CLP) method and against clinically isolated human ESKAPE pathogens ( Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa , and Enterobacter species). The in vivo results clearly demonstrated a significant reduction in the bacterial load in different organs and in the inflammatory markers such as COX-2 and NF-κB via activation of SIRT1 in mice treated with imipenem, a choice of antibiotic for polymicrobial sepsis treatment. Combinatorial treatment of ampicillin and celecoxib was effective on clinical isolates of ESKAPE pathogens, 45% of tested clinical isolates showed more than 50% reduction in the colony forming units when compared to ampicillin alone. In conclusion, this non-traditional treatment strategy might be effective in clinic to reduce the dose of antibiotic to treat drug-resistant bacterial infections.

  16. Expression levels of the receptor activator of NF-κB ligand and osteoprotegerin and the number of gram-negative bacteria in symptomatic and asymptomatic periapical lesions.

    Science.gov (United States)

    Carneiro, E; Parolin, A B; Wichnieski, C; Rosa, E A R; Silva Neto, U X; Westphalen, V P D; Fariniuk, L F; Johann, A C B R

    2017-01-01

    The study aimed to verify the potential correlation between the detected amount of gram-negative bacteria and the radiographic sizes of the lesions in patients with symptomatic and asymptomatic apical periodontitis. Furthermore, to evaluate whether the expression of receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG) and the RANKL/OPG ratio are differentially regulated in both groups. Twenty patients with periapical lesions were divided into two groups: symptomatic (SYM) n=10 and asymptomatic (ASYM) n=10. After periapical surgery, the lesions were collected and processed for histological examination, and immunohistochemistry. The percentage of RANKL- and OPG-immunopositive areas relative to the total area of the microscopic field was calculated. For gram staining, the number of gram-negative cells per microscopic field was assessed. The radiographs of each patient were processed and measured. The Student's t-test and the Pearson correlation coefficient were performed. The SYM group showed a significantly higher number of gram-negative cells (p=0.007) when compared to the ASYM group. A higher number of gram-negative bacteria occurred more frequently in larger periapical lesions and the SYM group (p=0.03). The expression for RANKL and OPG and the RANKL/OPG ratio were not significantly different between the groups. There was a significant positive correlation between the number of bacteria and OPG levels in the SYM group (p=0.01). The number of bacteria seems to influence the symptoms and the radiographic size of a periapical lesion. Gram-negative bacteria may play an important role in OPG activity in the SYM group. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Prospects and challenges of developing new agents for tough Gram-negatives.

    Science.gov (United States)

    Meyer, Annette L

    2005-10-01

    Historically, the medical profession has been successful in treating most bacterial infections in humans with synthetic second- and third-generation antibiotics. Recently, the prospects for continued success have dimmed with the increase in multidrug-resistant stains of bacteria. Infections caused by the Gram-negative bacteria Pseudomonas aeruginosa and Acinetobacter spp. in particular have increased in frequency and severity, and become progressively more difficult to treat. Contributors to disease severity include chronic infections due to mutator strains, persister cells and biofilms. The worst-case scenario of infections susceptible only to toxic polymixins is now a reality. The need to address the treatment of multidrug-resistant pathogens with innovative combination approaches and/or novel antibacterial agents is occurring in the context of reduced investment in antimicrobial drug discovery by the pharmaceutical industry.

  18. Conserved Bacterial-Binding Peptides of the Scavenger-Like Human Lymphocyte Receptor CD6 Protect From Mouse Experimental Sepsis

    Directory of Open Access Journals (Sweden)

    Mario Martínez-Florensa

    2018-04-01

    Full Text Available Sepsis is an unmet clinical need constituting one of the most important causes of death worldwide, a fact aggravated by the appearance of multidrug resistant strains due to indiscriminate use of antibiotics. Host innate immune receptors involved in pathogen-associated molecular patterns (PAMPs recognition represent a source of broad-spectrum therapies alternative or adjunctive to antibiotics. Among the few members of the ancient and highly conserved scavenger receptor cysteine-rich superfamily (SRCR-SF sharing bacterial-binding properties there is CD6, a lymphocyte-specific surface receptor. Here, we analyze the bacterial-binding properties of three conserved short peptides (11-mer mapping at extracellular SRCR domains of human CD6 (CD6.PD1, GTVEVRLEASW; CD6.PD2 GRVEMLEHGEW; and CD6.PD3, GQVEVHFRGVW. All peptides show high binding affinity for PAMPs from Gram-negative (lipopolysaccharide; Kd from 3.5 to 3,000 nM and Gram-positive (lipoteichoic acid; Kd from 36 to 680 nM bacteria. The CD6.PD3 peptide possesses broad bacterial-agglutination properties and improved survival of mice undergoing polymicrobial sepsis in a dose- and time-dependent manner. Accordingly, CD6.PD3 triggers a decrease in serum levels of both pro-inflammatory cytokines and bacterial load. Interestingly, CD6.PD3 shows additive survival effects on septic mice when combined with Imipenem/Cilastatin. These results illustrate the therapeutic potential of peptides retaining the bacterial-binding properties of native CD6.

  19. Metabolic and process engineering for biodesulfurization in Gram-negative bacteria.

    Science.gov (United States)

    Martínez, I; El-Said Mohamed, M; Santos, V E; García, J L; García-Ochoa, F; Díaz, E

    2017-11-20

    Microbial desulfurization or biodesulfurization (BDS) is an attractive low-cost and environmentally friendly complementary technology to the hydrotreating chemical process based on the potential of certain bacteria to specifically remove sulfur from S-heterocyclic compounds of crude fuels that are recalcitrant to the chemical treatments. The 4S or Dsz sulfur specific pathway for dibenzothiophene (DBT) and alkyl-substituted DBTs, widely used as model S-heterocyclic compounds, has been extensively studied at the physiological, biochemical and genetic levels mainly in Gram-positive bacteria. Nevertheless, several Gram-negative bacteria have been also used in BDS because they are endowed with some properties, e.g., broad metabolic versatility and easy genetic and genomic manipulation, that make them suitable chassis for systems metabolic engineering strategies. A high number of recombinant bacteria, many of which are Pseudomonas strains, have been constructed to overcome the major bottlenecks of the desulfurization process, i.e., expression of the dsz operon, activity of the Dsz enzymes, retro-inhibition of the Dsz pathway, availability of reducing power, uptake-secretion of substrate and intermediates, tolerance to organic solvents and metals, and other host-specific limitations. However, to attain a BDS process with industrial applicability, it is necessary to apply all the knowledge and advances achieved at the genetic and metabolic levels to the process engineering level, i.e., kinetic modelling, scale-up of biphasic systems, enhancing mass transfer rates, biocatalyst separation, etc. The production of high-added value products derived from the organosulfur material present in oil can be regarded also as an economically viable process that has barely begun to be explored. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Identifying patients with severe sepsis using administrative claims: patient-level validation of the angus implementation of the international consensus conference definition of severe sepsis.

    Science.gov (United States)

    Iwashyna, Theodore J; Odden, Andrew; Rohde, Jeffrey; Bonham, Catherine; Kuhn, Latoya; Malani, Preeti; Chen, Lena; Flanders, Scott

    2014-06-01

    Severe sepsis is a common and costly problem. Although consistently defined clinically by consensus conference since 1991, there have been several different implementations of the severe sepsis definition using ICD-9-CM codes for research. We conducted a single center, patient-level validation of 1 common implementation of the severe sepsis definition, the so-called "Angus" implementation. Administrative claims for all hospitalizations for patients initially admitted to general medical services from an academic medical center in 2009-2010 were reviewed. On the basis of ICD-9-CM codes, hospitalizations were sampled for review by 3 internal medicine-trained hospitalists. Chart reviews were conducted with a structured instrument, and the gold standard was the hospitalists' summary clinical judgment on whether the patient had severe sepsis. Three thousand one hundred forty-six (13.5%) hospitalizations met ICD-9-CM criteria for severe sepsis by the Angus implementation (Angus-positive) and 20,142 (86.5%) were Angus-negative. Chart reviews were performed for 92 randomly selected Angus-positive and 19 randomly-selected Angus-negative hospitalizations. Reviewers had a κ of 0.70. The Angus implementation's positive predictive value was 70.7% [95% confidence interval (CI): 51.2%, 90.5%]. The negative predictive value was 91.5% (95% CI: 79.0%, 100%). The sensitivity was 50.4% (95% CI: 14.8%, 85.7%). Specificity was 96.3% (95% CI: 92.4%, 100%). Two alternative ICD-9-CM implementations had high positive predictive values but sensitivities of Angus implementation of the international consensus conference definition of severe sepsis offers a reasonable but imperfect approach to identifying patients with severe sepsis when compared with a gold standard of structured review of the medical chart by trained hospitalists.

  1. Sepse Brasil: estudo epidemiológico da sepse em Unidades de Terapia Intensiva brasileiras An epidemiological study of sepsis in Intensive Care Units: Sepsis Brazil study

    Directory of Open Access Journals (Sweden)

    João Andrade L. Sales Júnior

    2006-03-01

    -22. The two main sources of infection were the respiratory tract (69% and the abdomen one (23.1%. Gram-negative bacilli were more prevalent (40.1%. Gram-positive cocci were identified in 32.8% and fungi infections in 5%. Mechanical ventilation was observed in 82.1% of the patients, Swan-Ganz catheter in 18.8%, vasopressors in 66.2% and hemotransfusion in 44.7%. CONCLUSIONS: It was observed a high mortality of sepsis in the ICUs in Brazil. The high frequency of septic shock demonstrated a group at high risk of death. In order to have a better use of the resources and reduce in mortality during the next 5 years, it is very important to identify our specific features related to this syndrome.

  2. A New Family of Capsule Polymerases Generates Teichoic Acid-Like Capsule Polymers in Gram-Negative Pathogens.

    Science.gov (United States)

    Litschko, Christa; Oldrini, Davide; Budde, Insa; Berger, Monika; Meens, Jochen; Gerardy-Schahn, Rita; Berti, Francesco; Schubert, Mario; Fiebig, Timm

    2018-05-29

    Group 2 capsule polymers represent crucial virulence factors of Gram-negative pathogenic bacteria. They are synthesized by enzymes called capsule polymerases. In this report, we describe a new family of polymerases that combine glycosyltransferase and hexose- and polyol-phosphate transferase activity to generate complex poly(oligosaccharide phosphate) and poly(glycosylpolyol phosphate) polymers, the latter of which display similarity to wall teichoic acid (WTA), a cell wall component of Gram-positive bacteria. Using modeling and multiple-sequence alignment, we showed homology between the predicted polymerase domains and WTA type I biosynthesis enzymes, creating a link between Gram-negative and Gram-positive cell wall biosynthesis processes. The polymerases of the new family are highly abundant and found in a variety of capsule-expressing pathogens such as Neisseria meningitidis , Actinobacillus pleuropneumoniae , Haemophilus influenzae , Bibersteinia trehalosi , and Escherichia coli with both human and animal hosts. Five representative candidates were purified, their activities were confirmed using nuclear magnetic resonance (NMR) spectroscopy, and their predicted folds were validated by site-directed mutagenesis. IMPORTANCE Bacterial capsules play an important role in the interaction between a pathogen and the immune system of its host. During the last decade, capsule polymerases have become attractive tools for the production of capsule polymers applied as antigens in glycoconjugate vaccine formulations. Conventional production of glycoconjugate vaccines requires the cultivation of the pathogen and thus the highest biosafety standards, leading to tremendous costs. With regard to animal husbandry, where vaccines could avoid the extensive use of antibiotics, conventional production is not sufficiently cost-effective. In contrast, enzymatic synthesis of capsule polymers is pathogen-free and fast, offers high stereo- and regioselectivity, and works with high efficacy

  3. Host Gene Expression Analysis in Sri Lankan Melioidosis Patients

    Science.gov (United States)

    2017-06-19

    CCL5 Chemokine (C-C motif) ligand 5 /RANTES. IFNγ Interferon gamma TNFα Tumor necrosis factor alpha HMGB1 High mobility group box 1 protein /high...aim of this study was to analyze gene expression levels of human host factors in melioidosis patients and establish useful correlation with disease...PBMC’s) of study subjects. Gene expression profiles of 25 gene targets including 19 immune response genes and 6 epigenetic factors were analyzed by

  4. Development of a miniaturised microarray-based assay for the rapid identification of antimicrobial resistance genes in Gram-negative bacteria

    DEFF Research Database (Denmark)

    Batchelor, Miranda; Hopkins, Katie L; Liebana, Ernesto

    2008-01-01

    We describe the development of a miniaturised microarray for the detection of antimicrobial resistance genes in Gram-negative bacteria. Included on the array are genes encoding resistance to aminoglycosides, trimethoprim, sulphonamides, tetracyclines and beta-lactams, including extended-spectrum ...

  5. Pharmacodynamic profiling of doripenem, imipenem and meropenem against prevalent Gram-negative organisms in the Asia-Pacific region.

    Science.gov (United States)

    Kiratisin, Pattarachai; Keel, Rebecca A; Nicolau, David P

    2013-01-01

    Carbapenems are increasingly being utilised owing to the escalating prevalence of antimicrobial-resistant Gram-negative bacteria from community and hospital settings. In this study, pharmacodynamic profiles of doripenem, imipenem and meropenem were evaluated against Gram-negative bacteria isolated from hospitalised patients. MICs for carbapenems were determined for Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii obtained from the COMPACT II programme conducted in the Asia-Pacific region. Monte Carlo simulations were undertaken to assess the pharmacodynamic profile of carbapenems against each of the pathogens. All carbapenem regimens achieved optimal exposures [cumulative fraction of response (CFR) ≥90%] against E. coli and K. pneumoniae. Against P. aeruginosa, doripenem achieved 81.3-95.3% CFR, imipenem achieved 55.2-77.9% CFR and meropenem achieved 71.9-91.3% CFR; only doripenem regimens of 4-h infusion of 1000 mg every 8h (q8h) and 1-h and 4-h infusion of 2000 mg q8h and a meropenem regimen of 3-h infusion of 2000 mg q8h obtained optimal exposures; all carbapenem regimens showed slight (1-7%) improvement in CFRs in favour of isolates collected from ICU sources. Against A. baumannii, CFRs were much lower (25.9-46.7% CFR) and no carbapenem regimens achieved optimal exposure in or outside the ICU. Owing to the high potency of carbapenems against these Enterobacteriaceae populations, standard regimens are likely to perform well in the Asia-Pacific region. However, larger doses combined with prolonged infusions will be required to increase the CFR for these carbapenems against resistant non-fermenting Gram-negatives such as P. aeruginosa and A. baumannii that are prevalent in these countries. Copyright © 2012 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

  6. Trends of Bloodstream Infections in a University Greek Hospital during a Three-Year Period: Incidence of Multidrug-Resistant Bacteria and Seasonality in Gram-negative Predominance.

    Science.gov (United States)

    Kolonitsiou, Fevronia; Papadimitriou-Olivgeris, Matthaios; Spiliopoulou, Anastasia; Stamouli, Vasiliki; Papakostas, Vasileios; Apostolopoulou, Eleni; Panagiotopoulos, Christos; Marangos, Markos; Anastassiou, Evangelos D; Christofidou, Myrto; Spiliopoulou, Iris

    2017-07-06

    The aim of the study was to assess the epidemiology, the incidence of multidrug-resistant bacteria and bloodstream infections' (BSIs) seasonality in a university hospital. This retrospective study was carried out in the University General Hospital of Patras, Greece, during 2011-13 y. Blood cultures from patients with clinical presentation suggestive of bloodstream infection were performed by the BacT/ALERT System. Isolates were identified by Vitek 2 Advanced Expert System. Antibiotic susceptibility testing was performed by the disk diffusion method and E-test. Resistance genes (mecA in staphylococci; vanA/vanB/vanC in enterococci; bla KPC /bla VIM /bla NDM in Klebsiella spp.) were detected by PCR. In total, 4607 (9.7%) blood cultures were positive from 47451 sets sent to Department of Microbiology, representing 1732 BSIs. Gram-negative bacteria (52.3%) were the most commonly isolated, followed by Gram-positive (39.5%), fungi (6.6%) and anaerobes bacteria (1.8%). The highest contamination rate was observed among Gram-positive bacteria (42.3%). Among 330 CNS and 150 Staphylococcus aureus, 281 (85.2%) and 60 (40.0%) were mecA-positive, respectively. From 113 enterococci, eight were vanA, two vanB and two vanC-positives. Of the total 207 carbapenem-resistant Klebsiella pneumoniae (73.4%), 202 carried bla KPC , four bla KPC and bla VIM and one bla VIM . A significant increase in monthly BSIs' incidence was shown (R2: 0.449), which may be attributed to a rise of Gram-positive BSIs (R2: 0.337). Gram-positive BSIs were less frequent in spring (P period. The increasing incidence of BSIs can be attributed to an increase of Gram-positive BSI incidence, even though Gram-negative bacteria remained the predominant ones. Seasonality may play a role in the predominance of Gram-negative's BSI.

  7. Defining Multidrug Resistance of Gram-Negative Bacteria in the Dutch-German Border Region-Impact of National Guidelines.

    Science.gov (United States)

    Köck, Robin; Siemer, Philipp; Esser, Jutta; Kampmeier, Stefanie; Berends, Matthijs S; Glasner, Corinna; Arends, Jan P; Becker, Karsten; Friedrich, Alexander W

    2018-01-26

    Preventing the spread of multidrug-resistant Gram-negative bacteria (MDRGNB) is a public health priority. However, the definition of MDRGNB applied for planning infection prevention measures such as barrier precautions differs depending on national guidelines. This is particularly relevant in the Dutch-German border region, where patients are transferred between healthcare facilities located in the two different countries, because clinicians and infection control personnel must understand antibiograms indicating MDRGNB from both sides of the border and using both national guidelines. This retrospective study aimed to compare antibiograms of Gram-negative bacteria and classify them using the Dutch and German national standards for MDRGNB definition. A total of 31,787 antibiograms from six Dutch and four German hospitals were classified. Overall, 73.7% were no MDRGNB according to both guidelines. According to the Dutch and German guideline, 7772/31,787 (24.5%) and 4586/31,787 (12.9%) were MDRGNB, respectively ( p Dutch-German border, as it cannot be assumed that MDRGNB requiring special hygiene precautions are marked in the transferred antibiograms in accordance with both national guidelines.

  8. The impact of the types of microorganisms isolated from blood and wounds on the results of treatment in burn patients with sepsis.

    Science.gov (United States)

    Glik, Justyna; Kawecki, Marek; Gaździk, Tadeusz; Nowak, Mariusz

    2012-01-01

    Despite development of combustiology, infections continue to be the most important cause of death among patients with burns. Sepsis is the most severe clinical presentation of infection in patients after thermal injuries who require immediate treatment. Early diagnosis and proper treatment of sepsis are important in the clinical management that is often hampered for multiple reasons, e.g. impaired patient immunity, problems with microorganisms with multi-antibacterial drug resistance. The aim of the study was to assess effect of type of a microorganism isolated from blood and wound on results of treatment of sepsis in patients with burns. Effect of type of microorganisms isolated from blood and wound on the result of treatment of sepsis was studied in 338 patients hospitalized immediately after an injury in Centre for Burn Treatment in Siemianowice Śląskie in years 2003 - 2004 (at the age of 18 - 96 years, 66 women and 272 men). Clinical symptoms of generalized infection were found in all study subjects. The study group was divided into two subgroups: cured patients and patients who died of sepsis. The following parameters were assessed in both subgroups: type of microorganism isolated from blood, type of microorganism isolated from wound as well as occurrence of the same and different infections of blood and burn wound. positive blood cultures were found in 165 patients (48.8%), 106 (64.2%) were cured, 59 (35.8%) died. The most commonly isolated microorganisms in cured patients were Gram(+) Staphylococcus epidermidis MRSE (19.81%) and Staphylococcus aureus MRSA (18.87%). Gram(-) intestinal rods were least commonly isolated from this group. The most commonly isolated microorganisms from blood of patients who were to die, included non-fermenting Gram(-) rods Acinetobacter baumannii (35.59%) and Pseudomonas aeruginosa (22.03%). Mixed bacterial flora was found in the blood of 22.03% patients. Among patients who were to die, the same microorganisms were found in the

  9. A Randomized Trial of the Amikacin Fosfomycin Inhalation System for the Adjunctive Therapy of Gram-Negative Ventilator-Associated Pneumonia: IASIS Trial.

    Science.gov (United States)

    Kollef, Marin H; Ricard, Jean-Damien; Roux, Damien; Francois, Bruno; Ischaki, Eleni; Rozgonyi, Zsolt; Boulain, Thierry; Ivanyi, Zsolt; János, Gál; Garot, Denis; Koura, Firas; Zakynthinos, Epaminondas; Dimopoulos, George; Torres, Antonio; Danker, Wayne; Montgomery, A Bruce

    2017-06-01

    Clinical failures in ventilator-associated pneumonia (VAP) caused by gram-negative bacteria are common and associated with substantial morbidity, mortality, and resource utilization. We assessed the safety and efficacy of the amikacin fosfomycin inhalation system (AFIS) for the treatment of gram-negative bacterial VAP in a randomized double-blind, placebo-controlled, parallel group, phase 2 study between May 2013 and March 2016. We compared standard of care in each arm plus 300 mg amikacin/120 mg fosfomycin or placebo (saline), delivered by aerosol twice daily for 10 days (or to extubation if < 10 days) via the investigational eFlow Inline System (PARI GmbH). The primary efficacy end point was change from baseline in the Clinical Pulmonary Infection Score (CPIS) during the randomized course of AFIS/placebo, using the subset of patients with microbiologically proven baseline infections with gram-negative bacteria. There were 143 patients randomized: 71 to the AFIS group, and 72 to the placebo group. Comparison of CPIS change from baseline between treatment groups was not different (P = .70). The secondary hierarchical end point of no mortality and clinical cure at day 14 or earlier was also not significant (P = .68) nor was the hierarchical end point of no mortality and ventilator-free days (P = .06). The number of deaths in the AFIS group was 17 (24%) and 12 (17%) in the placebo group (P = .32). The AFIS group had significantly fewer positive tracheal cultures on days 3 and 7 than placebo. In this trial of adjunctive aerosol therapy compared with standard of care IV antibiotics in patients with gram-negative VAP, the AFIS was ineffective in improving clinical outcomes despite reducing bacterial burden. ClinicalTrials.gov; No.: NCT01969799; URL: www.clinicaltrials.gov. Copyright © 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

  10. Post operative infection and sepsis in humans is associated with deficient gene expression of gammac cytokines and their apoptosis mediators.

    LENUS (Irish Health Repository)

    White, Mary

    2011-06-28

    Abstract Introduction Lymphocyte homeostasis is dependent on the γc cytokines. We hypothesised that sepsis in humans is associated with differential gene expression of the γc cytokines and their associated apoptosis mediators. Methods The study population consisted of a total of 60 patients with severe sepsis, 15 with gram negative bacteraemia, 10 healthy controls and 60 patients undergoing elective lung resection surgery. Pneumonia was diagnosed by CDC NNIC criteria. Gene expression in peripheral blood leukocytes (PBLs) of interleukin (IL)-2, 7, 15 and interferon (IFN)-γ, Bax, Bim, Bcl-2 was determined by qRT-PCR and IL-2 and IL-7 serum protein levels by ELISA. Gene expression of IL-2, 7 and IFN-γ was measured in peripheral blood leukocytes (PBL), cultured in the presence of lipopolysacharide (LPS) and CD3 binding antibody (CD3ab) Results IL-2 gene expression was lower in the bacteraemia group compared with controls, and lower still in the sepsis group (P < 0.0001). IL-7 gene expression was similar in controls and bacteraemia, but lower in sepsis (P < 0.0001). IL-15 gene expression was similar in the three groups. Bcl-2 gene expression was less (P < 0.0001) and Bim gene expression was greater (P = 0.0003) in severe sepsis compared to bacteraemic and healthy controls. Bax gene expression was similar in the three groups. In lung resection surgery patients, post-operative pneumonia was associated with a perioperative decrease in IL-2 mRNA (P < 0.0001) and IL-7 mRNA (P = 0.003). IL-2 protein levels were reduced in sepsis and bacteraemia compared to controls (P = 0.02) but similar in pneumonia and non-pneumonia groups. IL-7 protein levels were similar in all groups. In cultured PBLs, IFN-γ gene expression was decreased in response to LPS and increased in response to CD3ab with sepsis: IL-7 gene expression increased in response to LPS in controls and to CD3ab with sepsis; Bcl-2 gene expression decreased in response to combined CD3ab and IL-2 with sepsis

  11. Trends of 9,416 multidrug-resistant Gram-negative bacteria

    Directory of Open Access Journals (Sweden)

    Viviane Decicera Colombo Oliveira

    2015-06-01

    Full Text Available Summary Objective: a resistance of hospital-acquired bacteria to multiple antibiotics is a major concern worldwide. The objective of this study was to investigate multidrugresistant (MDR bacteria, clinical specimens, origin of specimen and trends, and correlate these with bacterial sensitivity and consumption of antimicrobials. Methods: 9,416 bacteria of nosocomial origin were evaluated in a tertiary hospital, from 1999 to 2008. MDR was defined for Gram-negative bacteria (GNB as resistance to two or more classes/groups of antibiotics. Results: GNB MDR increased by 3.7 times over the study period (p<0.001. Acinetobacter baumannii was the most prevalent (36.2%. Over the study period, there were significant 4.8-fold and 14.6-fold increases for A. baumannii and K. pneumoniae (p<0.001, respectively. Sixty-seven percent of isolates of MDR GNB were isolated in intensive care units. The resistance of A. baumannii to carbapenems increased from 7.4 to 57.5% during the study period and concomitant with an increased consumption. Conclusion: that decade showed prevalence of GNB and a gradual increase in MDR GNB. There was an increase in carbapenem resistance of 50.1% during the study.

  12. Induction of gram-negative bacterial growth by neurochemical containing banana (Musa x paradisiaca) extracts.

    Science.gov (United States)

    Lyte, M

    1997-09-15

    Bananas contain large quantities of neurochemicals. Extracts from the peel and pulp of bananas in increasing stages of ripening were prepared and evaluated for their ability to modulate the growth of non-pathogenic and pathogenic bacteria. Extracts from the peel, and to a much lesser degree the pulp, increased the growth of Gram-negative bacterial strains Escherichia coli O157:H7, Shigella flexneri, Enterobacter cloacae and Salmonella typhimurium, as well as two non-pathogenic E. coli strains, in direct relation to the content of norepinephrine and dopamine, but not serotonin. The growth of Gram-positive bacteria was not altered by any of the extracts. Supplementation of vehicle and pulp cultures with norepinephrine or dopamine yielded growth equivalent to peel cultures. Total organic analysis of extracts further demonstrated that the differential effects of peel and pulp on bacterial growth was not nutritionally based, but due to norepinephrine and dopamine. These results suggest that neurochemicals contained within foodstuffs may influence the growth of pathogenic and indigenous bacteria through direct neurochemical-bacterial interactions.

  13. Silver resistance in Gram-negative bacteria: a dissection of endogenous and exogenous mechanisms.

    Science.gov (United States)

    Randall, Christopher P; Gupta, Arya; Jackson, Nicole; Busse, David; O'Neill, Alex J

    2015-04-01

    To gain a more detailed understanding of endogenous (mutational) and exogenous (horizontally acquired) resistance to silver in Gram-negative pathogens, with an emphasis on clarifying the genetic bases for resistance. A suite of microbiological and molecular genetic techniques was employed to select and characterize endogenous and exogenous silver resistance in several Gram-negative species. In Escherichia coli, endogenous resistance arose after 6 days of exposure to silver, a consequence of two point mutations that were both necessary and sufficient for the phenotype. These mutations, in ompR and cusS, respectively conferred loss of the OmpC/F porins and derepression of the CusCFBA efflux transporter, both phenotypic changes previously linked to reduced intracellular accumulation of silver. Exogenous resistance involved derepression of the SilCFBA efflux transporter as a consequence of mutation in silS, but was additionally contingent on expression of the periplasmic silver-sequestration protein SilE. Silver resistance could be selected at high frequency (>10(-9)) from Enterobacteriaceae lacking OmpC/F porins or harbouring the sil operon and both endogenous and exogenous resistance were associated with modest fitness costs in vitro. Both endogenous and exogenous silver resistance are dependent on the derepressed expression of closely related efflux transporters and are therefore mechanistically similar phenotypes. The ease with which silver resistance can become selected in some bacterial pathogens in vitro suggests that there would be benefit in improved surveillance for silver-resistant isolates in the clinic, along with greater control over use of silver-containing products, in order to best preserve the clinical utility of silver. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy.

  14. [Uncommon non-fermenting Gram-negative rods as pathogens of lower respiratory tract infection].

    Science.gov (United States)

    Juhász, Emese; Iván, Miklós; Pongrácz, Júlia; Kristóf, Katalin

    2018-01-01

    Glucose non-fermenting Gram-negative bacteria are ubiquitous environmental organisms. Most of them are identified as opportunistic, nosocomial pathogens in patients. Uncommon species are identified accurately, mainly due to the introduction of matrix-assisted laser desorption-ionization time of flight mass spectrometry (MALDI-TOF MS) in clinical microbiology practice. Most of these uncommon non-fermenting rods are isolated from lower respiratory tract samples. Their significance in lower respiratory tract infections, such as rules of their testing are not clarified yet. The aim of this study was to review the clinical microbiological features of these bacteria, especially their roles in lower respiratory tract infections and antibiotic treatment options. Lower respiratory tract samples of 3589 patients collected in a four-year period (2013-2016) were analyzed retrospectively at Semmelweis University (Budapest, Hungary). Identification of bacteria was performed by MALDI-TOF MS, the antibiotic susceptibility was tested by disk diffusion method. Stenotrophomonas maltophilia was revealed to be the second, whereas Acinetobacter baumannii the third most common non-fermenting rod in lower respiratory tract samples, behind the most common Pseudomonas aeruginosa. The total number of uncommon non-fermenting Gram-negative isolates was 742. Twenty-three percent of isolates were Achromobacter xylosoxidans. Beside Chryseobacterium, Rhizobium, Delftia, Elizabethkingia, Ralstonia and Ochrobactrum species, and few other uncommon species were identified among our isolates. The accurate identification of this species is obligatory, while most of them show intrinsic resistance to aminoglycosides. Resistance to ceftazidime, cefepime, piperacillin-tazobactam and carbapenems was frequently observed also. Ciprofloxacin, levofloxacin and trimethoprim-sulfamethoxazole were found to be the most effective antibiotic agents. Orv Hetil. 2018; 159(1): 23-30.

  15. Comparison of beta-lactam regimens for the treatment of gram-negative pulmonary infections in the intensive care unit based on pharmacokinetics/pharmacodynamics.

    Science.gov (United States)

    Burgess, David S; Frei, Christopher R

    2005-11-01

    This study utilized pharmacokinetics/pharmacodynamics to compare beta-lactam regimens for the empirical and definitive treatment of gram-negative pulmonary infections in the ICU. Susceptibility data were extracted from the 2002 Intensive Care Unit Surveillance System (ISS) and pharmacokinetic parameters were obtained from published human studies. Monte Carlo simulation was used to model the free percent time above the MIC (free %T > MIC) for 18 beta-lactam regimens against all gram-negative isolates, Enterobacteriaceae, Pseudomonas aeruginosa and Acinetobacter baumannii. The cumulative fraction of response (CFR) was determined for bacteriostatic and bactericidal targets (free %T > MIC): penicillins (> or = 30/50%), cephalosporins/monobactams (> or = 40/70%) and carbapenems (> or = 20/40%). The 2002 ISS database contained MICs for 2408 gram-negative isolates including 1430 Enterobacteriaceae, 799 P. aeruginosa, and 179 A. baumannii. Imipenem had the highest percentage susceptible for all gram-negatives, Enterobacteriaceae and A. baumannii, while piperacillin/tazobactam had the highest percentage susceptible for P. aeruginosa. For empirical therapy, imipenem 0.5 g every 6 h, cefepime 2 g every 8 h and ceftazidime 2 g every 8 h demonstrated the highest CFR. For definitive therapy, imipenem 0.5 g every 6 h, ertapenem 1 g daily and cefepime 2 g every 8 h, cefepime 1 g every 8 h and cefepime 1 g every 12 h had the highest bactericidal CFR against Enterobacteriaceae; ceftazidime 2 g every 8 h, cefepime 2 g every 8 h, piperacillin/tazobactam 3.375 g every 4 h, ceftazidime 1 g every 8 h and aztreonam 1 g every 8 h against P. aeruginosa; and imipenem 0.5 g every 6 h, ticarcillin/clavulanate 3.1 g every 4 h, ceftazidime 2 g every 8 h, cefepime 2 g every 8 h and ticarcillin/clavulanate 3.1 g every 6 h against A. baumannii. Based on pharmacokinetics/pharmacodynamics, imipenem 0.5 g every 6 h, cefepime 2 g every 8 h and ceftazidime 2 g every 8 h should be the preferred beta

  16. Distribution of Gram Negative Bacteria and Evaluation of Resistance Profiles

    Directory of Open Access Journals (Sweden)

    Serap Pamukcuoglu

    2014-03-01

    Full Text Available Aim: In this study, we aimed to examine the distributon of Gram negative bacteria isolated from urine cultures of out-patients in Afyonkarahisar State Hospital and evaluate the antimicrobial resistance rates of these pathogens. Material and Method: Urine samples of out-patients which were sent to microbiology laboratory between 2012-2013 were retrospectively evaluated. The isolates were identified using conventional methods and/or automated Vitec 2.0 system. Antibiogram sensitivities were determined by Kirby-Bauer disc diffusion method or automated system and interpreted on the basis of Clinical and Laboratory Standards Institute (CSI criteria. Double disc sinergy test (DDST or Vitec 2.0 system was used to detect extended spectrum beta-lactamase (ESBL.When conventional methods could%u2019t be clarified according to their colony morphologies, gram staining patterns, biochemical test; automated system has been used. Results: A total of 671 isolates acquired from urine samples were studied. 427 Escherichia coli (63.6 %, 165 Klebsiella spp. (24.6 %, 22 Pseudomonas spp. (3.3 %, nine Acinetobacter spp. (1.3 %, 41 Proteus spp. (6.1 % and seven Serratia (1.0 % strains were identified among isolates. 97 E.coli (22.8 % and 41 Klebsiella (24.8 % isolates were ESBL positive. Most common bacteria were E.coli, 31.1 % of which were resistant to trimethoprim-sulfamethoxazole, 16 % to ciprofloxacin and 3.6 % to nitrofurantoin. Among Enterobacteriaceae, no resistance aganist carbapenems were detected. Moreover, aminoglicoside sensitivity rate was significantly high in this group. Discussion: Microorganisms that have progressively increasing antimicrobial resistance should be considered in the treatment of urinary tract infections. It is also important to use the most appropriate antibiotics to avoid unnecessary usage of these drugs in order to decrease drug resistance rates and ESBL production which may effect the success of the treatment.

  17. Carbapenem resistance, inappropriate empiric treatment and outcomes among patients hospitalized with Enterobacteriaceae urinary tract infection, pneumonia and sepsis.

    Science.gov (United States)

    Zilberberg, Marya D; Nathanson, Brian H; Sulham, Kate; Fan, Weihong; Shorr, Andrew F

    2017-04-17

    Drug resistance among gram-negative pathogens is a risk factor for inappropriate empiric treatment (IET), which in turn increases the risk for mortality. We explored the impact of carbapenem-resistant Enterobacteriaceae (CRE) on the risk of IET and of IET on outcomes in patients with Enterobacteriaceae infections. We conducted a retrospective cohort study in Premier Perspective database (2009-2013) of 175 US hospitals. We included all adult patients with community-onset culture-positive urinary tract infection (UTI), pneumonia, or sepsis as a principal diagnosis, or as a secondary diagnosis in the setting of respiratory failure, treated with antibiotics within 2 days of admission. We employed regression modeling to compute adjusted association of presence of CRE with risk of receiving IET, and of IET on hospital mortality, length of stay (LOS) and costs. Among 40,137 patients presenting to the hospital with an Enterobacteriaceae UTI, pneumonia or sepsis, 1227 (3.1%) were CRE. In both groups, the majority of the cases were UTI (51.4% CRE and 54.3% non-CRE). Those with CRE were younger (66.6+/-15.3 vs. 69.1+/-15.9 years, p pneumonia or sepsis was comparable to other national estimates. Infection with CRE was associated with a four-fold increased risk of receiving IET, which in turn increased mortality, LOS and costs.

  18. [Identification of anaerobic gram-negative bacilli isolated from various clinical specimens and determination of antibiotic resistance profiles with E-test methods].

    Science.gov (United States)

    Demir, Cengiz; Keşli, Recep

    2018-01-01

    The aim of this study was to identify gram-negative anaerobic bacilli isolated from various clinical specimens that were obtained from patients with suspected anaerobic infections and to determine the antibiotic resistance profiles by using the antibiotic concentration gradient method. The study was performed in Afyon Kocatepe University Ahmet Necdet Sezer Research and Practice Hospital, Medical Microbiology Laboratory between 1 November 2014 and 30 October 2015. Two hundred and seventyeight clinical specimens accepted for anaerobic culture were enrolled in the study. All the samples were cultivated anaerobically by using Schaedler agar with 5% defibrinated sheep blood and Schaedler broth. The isolated anaerobic gram-negative bacilli were identified by using both the conventional methods and automated identification system (VITEK 2, bioMerieux, France). Antibiotic susceptibility tests were performed with antibiotic concentration gradient method (E-test, bioMerieux, France); against penicillin G, clindamycin, cefoxitin, metronidazole, moxifloxacin, imipenem, meropenem, ertapenem and doripenem for each isolate. Of the 28 isolated anaerobic gram-negative bacilli; 14 were identified as Bacteroides fragilis group, 9 were Prevotella spp., and 5 were Fusobacterium spp. The highest resistance rate was found against penicillin (78.5%) and resistance rates against clindamycin and cefoxitin were found as 17.8% and 21.4%, respectively. No resistance was found against metronidazole, moxifloxacin, imipenem, meropenem, ertapenem and doripenem. As a result, isolation and identification of anaerobic bacteria are difficult, time-consuming and more expensive when compared with the cost of aerobic culture. The rate of anaerobic bacteria isolation may be increased by obtaining the appropriate clinical specimen and appropriate transportation of these specimens. We believe that the data obtained from the study in our center may offer benefits for the follow up and treatment of infections

  19. Antimicrobial susceptibility trends among gram-positive and -negative clinical isolates collected between 2005 and 2012 in Mexico: results from the Tigecycline Evaluation and Surveillance Trial.

    Science.gov (United States)

    Morfin-Otero, Rayo; Noriega, Eduardo Rodriguez; Dowzicky, Michael J

    2015-12-15

    The Tigecycline Evaluation and Surveillance Trial (T.E.S.T) is a global antimicrobial surveillance study of both gram-positive and gram-negative organisms. This report presents data on antimicrobial susceptibility among organisms collected in Mexico between 2005 and 2012 as part of T.E.S.T., and compares rates between 2005-2007 and 2008-2012. Each center in Mexico submitted at least 200 isolates per collection year; including 65 gram-positive isolates and 135 gram-negative isolates. Minimum inhibitory concentrations (MICs) were determined using Clinical Laboratory Standards Institute (CLSI) broth microdilution methodology and antimicrobial susceptibility was established using the 2013 CLSI-approved breakpoints. For tigecycline US Food and Drug Administration (FDA) breakpoints were applied. Isolates of E. coli and K. pneumoniae with a MIC for ceftriaxone of >1 mg/L were screened for ESBL production using the phenotypic confirmatory disk test according to CLSI guidelines. The rates of some key resistant phenotypes changed during this study: vancomycin resistance among Enterococcus faecium decreased from 28.6 % in 2005-2007 to 19.1 % in 2008-2012, while β-lactamase production among Haemophilus influenzae decreased from 37.6 to 18.9 %. Conversely, methicillin-resistant Staphylococcus aureus increased from 38.1 to 47.9 %, meropenem-resistant Acinetobacter spp. increased from 17.7 to 33.0 % and multidrug-resistant Acinetobacter spp. increased from 25.6 to 49.7 %. The prevalence of other resistant pathogens was stable over the study period, including extended-spectrum β-lactamase-positive Escherichia coli (39.0 %) and Klebsiella pneumoniae (25.0 %). The activity of tigecycline was maintained across the study years with MIC90s of ≤2 mg/L against Enterococcus spp., S. aureus, Streptococcus agalactiae, Streptococcus pneumoniae, Enterobacter spp., E. coli, K. pneumoniae, Klebsiella oxytoca, Serratia marcescens, H. influenzae, and Acinetobacter spp. All gram

  20. First report of sepsis due to Catabacter hongkongensis in an Italian patient

    Directory of Open Access Journals (Sweden)

    A. Torri

    2016-01-01

    Full Text Available The first isolation of Catabacter hongkongensis in Italy is reported. Pleomorphic Gram-positive rods were grown in blood cultures from samples obtained from a 55-year-old patient admitted to the intensive care unit with sepsis after he experienced massive thoracic and abdominal trauma. The identification was obtained by amplification and sequencing of the 16S rRNA gene.

  1. Comparing the harmful effects of nontuberculous mycobacteria and Gram negative bacteria on lung function in patients with cystic fibrosis

    DEFF Research Database (Denmark)

    Qvist, Tavs; Taylor-Robinson, David; Waldmann, Elisabeth

    2015-01-01

    BACKGROUND: To better understand the relative effects of infection with nontuberculous mycobacteria and Gram negative bacteria on lung function decline in cystic fibrosis, we assessed the impact of each infection in a Danish setting. METHODS: Longitudinal registry study of 432 patients with cystic...

  2. In vitro antimicrobial activity of five essential oils on multi-drug resistant Gram-negative clinical isolates

    OpenAIRE

    Hercules Sakkas; Panagiota Gousia; Vangelis Economou; Vassilios Sakkas; Stefanos Petsios; Chrissanthy Papadopoulou

    2016-01-01

    Aim/Background: The emergence of drug-resistant pathogens has drawn attention on medicinal plants for potential antimicrobial properties. The objective of the present study was the investigation of the antimicrobial activity of five plant essential oils on multidrug resistant Gram-negative bacteria. Materials and Methods: Basil, chamomile blue, origanum, thyme, and tea tree oil were tested against clinical isolates of Acinetobacter baumannii (n = 6), Escherichia coli (n = 4), Klebsiella pneum...

  3. The Synthetic Antimicrobial Peptide 19-2.5 Interacts with Heparanase and Heparan Sulfate in Murine and Human Sepsis.

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    Lukas Martin

    Full Text Available Heparanase is an endo-β-glucuronidase that cleaves heparan sulfate side chains from their proteoglycans. Thereby, heparanase liberates highly potent circulating heparan sulfate-fragments (HS-fragments and triggers the fatal and excessive inflammatory response in sepsis. As a potential anti-inflammatory agent for sepsis therapy, peptide 19-2.5 belongs to the class of synthetic anti-lipopolysaccharide peptides; however, its activity is not restricted to Gram-negative bacterial infection. We hypothesized that peptide 19-2.5 interacts with heparanase and/or HS, thereby reducing the levels of circulating HS-fragments in murine and human sepsis. Our data indicate that the treatment of septic mice with peptide 19-2.5 compared to untreated control animals lowers levels of plasma heparanase and circulating HS-fragments and reduces heparanase activity. Additionally, mRNA levels of heparanase in heart, liver, lung, kidney and spleen are downregulated in septic mice treated with peptide 19-2.5 compared to untreated control animals. In humans, plasma heparanase level and activity are elevated in septic shock. The ex vivo addition of peptide 19-2.5 to plasma of septic shock patients decreases heparanase activity but not heparanase level. Isothermal titration calorimetry revealed a strong exothermic reaction between peptide 19-2.5 and heparanase and HS-fragments. However, a saturation character has been identified only in the peptide 19-2.5 and HS interaction. In conclusion, the findings of our current study indicate that peptide 19-2.5 interacts with heparanase, which is elevated in murine and human sepsis and consecutively attenuates the generation of circulating HS-fragments in systemic inflammation. Thus, peptide 19-2.5 seems to be a potential anti-inflammatory agent in sepsis.

  4. Resistance among Gram-negative ESKAPE pathogens isolated from hospitalized patients with intra-abdominal and urinary tract infections in Latin American countries: SMART 2013-2015.

    Science.gov (United States)

    Karlowsky, James A; Hoban, Daryl J; Hackel, Meredith A; Lob, Sibylle H; Sahm, Daniel F

    Gram-negative ESKAPE pathogens (Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) are important etiologic agents of nosocomial infection that are frequently resistant to broad-spectrum antimicrobial agents. Gram-negative ESKAPE pathogens were collected from hospitalized patients in 11 Latin American countries from 2013 to 2015 as part of the Study for Monitoring Antimicrobial Resistance Trends (SMART) global surveillance program. In total, 2113 isolates from intra-abdominal infections (IAI) and 970 isolates from urinary tract infections (UTI) were tested against antimicrobial agents using standardized CLSI broth microdilution methodology. Of the agents tested, amikacin demonstrated the highest rates of susceptibility (%) for K. pneumoniae (92.2, 92.3), Enterobacter spp. (97.5, 92.1), and P. aeruginosa (85.3, 75.2) isolates from both IAI and UTI, respectively. Ertapenem (68.5, 62.6) and imipenem (79.2, 75.9) showed substantially higher rates of susceptibility (%) than other β-lactams, including piperacillin-tazobactam (35.9, 37.4) against ESBL-positive isolates of K. pneumoniae from IAI and UTI, respectively. Rates of susceptibility to all agents tested against A. baumannii were ≤30.9%. Gram-negative ESKAPE pathogens isolated from Latin America demonstrated compromised in vitro susceptibility to commonly prescribed broad-spectrum, parenteral antimicrobial agents. Continued surveillance is warranted. New antimicrobial agents with potent activity against Gram-negative ESKAPE pathogens are urgently needed. Copyright © 2017 Sociedade Brasileira de Infectologia. Published by Elsevier Editora Ltda. All rights reserved.

  5. Multicenter Evaluation of the Bruker MALDI Biotyper CA System for the Identification of Clinical Aerobic Gram-Negative Bacterial Isolates.

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    Matthew L Faron

    Full Text Available The prompt and accurate identification of bacterial pathogens is fundamental to patient health and outcome. Recent advances in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS have revolutionized bacterial identification in the clinical laboratory, but uniform incorporation of this technology in the U.S. market has been delayed by a lack of FDA-cleared systems. In this study, we conducted a multicenter evaluation of the MALDI Biotyper CA (MBT-CA System (Bruker Daltonics Inc, Billerica, MA for the identification of aerobic gram-negative bacteria as part of a 510(k submission to the FDA. A total of 2,263 aerobic gram negative bacterial isolates were tested representing 23 genera and 61 species. Isolates were collected from various clinical sources and results obtained from the MBT-CA System were compared to DNA sequencing and/or biochemical testing. Isolates that failed to report as a "high confidence species ID" [log(score ≥2.00] were re-tested using an extraction method. The MBT-CA System identified 96.8% and 3.1% of isolates with either a "high confidence" or a "low confidence" [log(score value between 1.70 and <2.00] species ID, respectively. Two isolates did not produce acceptable confidence scores after extraction. The MBT-CA System correctly identified 99.8% (2,258/2,263 to genus and 98.2% (2,222/2,263 to species level. These data demonstrate that the MBT-CA System provides accurate results for the identification of aerobic gram-negative bacteria.

  6. Multicenter Evaluation of the Bruker MALDI Biotyper CA System for the Identification of Clinical Aerobic Gram-Negative Bacterial Isolates.

    Science.gov (United States)

    Faron, Matthew L; Buchan, Blake W; Hyke, Josh; Madisen, Neil; Lillie, Jennifer L; Granato, Paul A; Wilson, Deborah A; Procop, Gary W; Novak-Weekley, Susan; Marlowe, Elizabeth; Cumpio, Joven; Griego-Fullbright, Christen; Kindig, Sandra; Timm, Karen; Young, Stephen; Ledeboer, Nathan A

    2015-01-01

    The prompt and accurate identification of bacterial pathogens is fundamental to patient health and outcome. Recent advances in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) have revolutionized bacterial identification in the clinical laboratory, but uniform incorporation of this technology in the U.S. market has been delayed by a lack of FDA-cleared systems. In this study, we conducted a multicenter evaluation of the MALDI Biotyper CA (MBT-CA) System (Bruker Daltonics Inc, Billerica, MA) for the identification of aerobic gram-negative bacteria as part of a 510(k) submission to the FDA. A total of 2,263 aerobic gram negative bacterial isolates were tested representing 23 genera and 61 species. Isolates were collected from various clinical sources and results obtained from the MBT-CA System were compared to DNA sequencing and/or biochemical testing. Isolates that failed to report as a "high confidence species ID" [log(score) ≥2.00] were re-tested using an extraction method. The MBT-CA System identified 96.8% and 3.1% of isolates with either a "high confidence" or a "low confidence" [log(score) value between 1.70 and <2.00] species ID, respectively. Two isolates did not produce acceptable confidence scores after extraction. The MBT-CA System correctly identified 99.8% (2,258/2,263) to genus and 98.2% (2,222/2,263) to species level. These data demonstrate that the MBT-CA System provides accurate results for the identification of aerobic gram-negative bacteria.

  7. Simultaneous fluorescent gram staining and activity assessment of activated sludge bacteria.

    Science.gov (United States)

    Forster, Scott; Snape, Jason R; Lappin-Scott, Hilary M; Porter, Jonathan

    2002-10-01

    Wastewater treatment is one of the most important commercial biotechnological processes, and yet the component bacterial populations and their associated metabolic activities are poorly understood. The novel fluorescent dye hexidium iodide allows assessment of Gram status by differential absorption through bacterial cell walls. Differentiation between gram-positive and gram-negative wastewater bacteria was achieved after flow cytometric analysis. This study shows that the relative proportions of gram-positive and gram-negative bacterial cells identified by traditional microscopy and hexidium iodide staining were not significantly different. Dual staining of cells for Gram status and activity proved effective in analyzing mixtures of cultured bacteria and wastewater populations. Levels of highly active organisms at two wastewater treatment plants, both gram positive and gram negative, ranged from 1.5% in activated sludge flocs to 16% in the activated sludge fluid. Gram-positive organisms comprised Gram status and activity within activated sludge samples over a 4-day period showed significant differences over time. This method provides a rapid, quantitative measure of Gram status linked with in situ activity within wastewater systems.

  8. Resistance among Gram-negative ESKAPE pathogens isolated from hospitalized patients with intra-abdominal and urinary tract infections in Latin American countries: SMART 2013–2015

    Directory of Open Access Journals (Sweden)

    James A. Karlowsky

    2017-05-01

    Full Text Available Gram-negative ESKAPE pathogens (Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species are important etiologic agents of nosocomial infection that are frequently resistant to broad-spectrum antimicrobial agents. Gram-negative ESKAPE pathogens were collected from hospitalized patients in 11 Latin American countries from 2013 to 2015 as part of the Study for Monitoring Antimicrobial Resistance Trends (SMART global surveillance program. In total, 2113 isolates from intra-abdominal infections (IAI and 970 isolates from urinary tract infections (UTI were tested against antimicrobial agents using standardized CLSI broth microdilution methodology. Of the agents tested, amikacin demonstrated the highest rates of susceptibility (% for K. pneumoniae (92.2, 92.3, Enterobacter spp. (97.5, 92.1, and P. aeruginosa (85.3, 75.2 isolates from both IAI and UTI, respectively. Ertapenem (68.5, 62.6 and imipenem (79.2, 75.9 showed substantially higher rates of susceptibility (% than other β-lactams, including piperacillin-tazobactam (35.9, 37.4 against ESBL-positive isolates of K. pneumoniae from IAI and UTI, respectively. Rates of susceptibility to all agents tested against A. baumannii were ≤30.9%. Gram-negative ESKAPE pathogens isolated from Latin America demonstrated compromised in vitro susceptibility to commonly prescribed broad-spectrum, parenteral antimicrobial agents. Continued surveillance is warranted. New antimicrobial agents with potent activity against Gram-negative ESKAPE pathogens are urgently needed.

  9. Phenotypic and Genotypic Detection of Metallo-beta-lactamases among Imipenem-Resistant Gram Negative Isolates

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    Mohammad Mohammadzadeh

    2016-08-01

    Full Text Available Background:   Imipenem-resistant gram negative bacteria, resulting from metallo-beta-lactamase (MBLs-producing strains have been reported to be among the important causes of nosocomial infections and of serious therapeutic problem worldwide. Because of their broad range, potent carbapenemase activity and resistance to inhibitors, these enzymes can confer resistance to almost all beta-lactams. The prevalence of metallo-beta-lactamase among imipenem-resistant Acinetobacter spp., Pseudomonas spp. and Enerobacteriaceae isolates is determined.Methods:   In this descriptive study 864 clinical isolates of Acinetobacter spp., Pseudomonas spp. and Enterobacteriaceae, were initially tested for imipenem susceptibility. The metallo-beta-lactamase production was detected using combined disk diffusion, double disk synergy test, and Hodge test. Then all imipenem resistant isolates were tested by PCR for imp, vim and ndm genes. Results:   Among 864 isolates, 62 (7.17 % were imipenem-resistant. Positive phonetypic test for metallo-beta-lactamase was 40 (64.5%, of which 24 (17.1% and 16 (9.2% isolates were Acinetobacter spp. and Pseudomonas spp., respectively. By PCR method 30 (48.4% of imipenem resistant Acinetobacter, and Pseudomonas isolates were positive for MBL-producing genes. None of the Enterobacteriaceae isolates were positive for metallo-beta-lactamase activity. Conclusion:   The results of this study are indicative of the growing number of nosocomial infections associated with multidrug-resistant gram negative bacteria in this region leading to difficulties in antibiotic therapy. Thereby, using of phenotypic methods can be helpful for management of this problem.

  10. Activities of daily living associated with acquisition of melioidosis in northeast Thailand: a matched case-control study.

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    Direk Limmathurotsakul

    Full Text Available Melioidosis is a serious infectious disease caused by the Category B select agent and environmental saprophyte, Burkholderia pseudomallei. Most cases of naturally acquired infection are assumed to result from skin inoculation after exposure to soil or water. The aim of this study was to provide evidence for inoculation, inhalation and ingestion as routes of infection, and develop preventive guidelines based on this evidence.A prospective hospital-based 1∶2 matched case-control study was conducted in Northeast Thailand. Cases were patients with culture-confirmed melioidosis, and controls were patients admitted with non-infectious conditions during the same period, matched for gender, age, and diabetes mellitus. Activities of daily living were recorded for the 30-day period before onset of symptoms, and home visits were performed to obtain drinking water and culture this for B. pseudomallei. Multivariable conditional logistic regression analysis based on 286 cases and 512 controls showed that activities associated with a risk of melioidosis included working in a rice field (conditional odds ratio [cOR] = 2.1; 95% confidence interval [CI] 1.4-3.3, other activities associated with exposure to soil or water (cOR = 1.4; 95%CI 0.8-2.6, an open wound (cOR = 2.0; 95%CI 1.2-3.3, eating food contaminated with soil or dust (cOR = 1.5; 95%CI 1.0-2.2, drinking untreated water (cOR = 1.7; 95%CI 1.1-2.6, outdoor exposure to rain (cOR = 2.1; 95%CI 1.4-3.2, water inhalation (cOR = 2.4; 95%CI 1.5-3.9, current smoking (cOR = 1.5; 95%CI 1.0-2.3 and steroid intake (cOR = 3.1; 95%CI 1.4-6.9. B. pseudomallei was detected in water source(s consumed by 7% of cases and 3% of controls (cOR = 2.2; 95%CI 0.8-5.8.We used these findings to develop the first evidence-based guidelines for the prevention of melioidosis. These are suitable for people in melioidosis-endemic areas, travelers and military personnel. Public health campaigns

  11. White shrimp (Litopenaeus vannamei) recombinant lysozyme has antibacterial activity against Gram negative bacteria: Vibrio alginolyticus, Vibrio parahemolyticus and Vibrio cholerae.

    Science.gov (United States)

    de-la-Re-Vega, Enrique; García-Galaz, Alfonso; Díaz-Cinco, Martha E; Sotelo-Mundo, Rogerio R

    2006-03-01

    C-type lysozyme has been described as an antibacterial component of the shrimp innate defence system. We determined quantitatively the antibacterial activity of white shrimp (Litopenaeus vannamei) recombinant lysozyme against three Gram negative bacteria: Vibrio alginolyticus, Vibrio parahemolyticus and Vibrio cholerae, using a turbidimetric assay with live bacteria and differential bacterial viable count after interaction with the protein. In conclusion, the antibacterial activity of recombinant shrimp lysozyme against Vibrio sp. is at least equal to the values against the Gram positive M. luteus and more active against the shrimp pathogens V. alginolyticus and V. parahemolyticus.

  12. Selective bowel decontamination results in gram-positive translocation.

    Science.gov (United States)

    Jackson, R J; Smith, S D; Rowe, M I

    1990-05-01

    Colonization by enteric gram-negative bacteria with subsequent translocation is believed to be a major mechanism for infection in the critically ill patient. Selective bowel decontamination (SBD) has been used to control gram-negative infections by eliminating these potentially pathogenic bacteria while preserving anaerobic and other less pathogenic organisms. Infection with gram-positive organisms and anaerobes in two multivisceral transplant patients during SBD led us to investigate the effect of SBD on gut colonization and translocation. Twenty-four rats received enteral polymixin E, tobramycin, amphotericin B, and parenteral cefotaxime for 7 days (PTA + CEF); 23 received parenteral cefotaxime alone (CEF), 19 received the enteral antibiotics alone (PTA), 21 controls received no antibiotics. Cecal homogenates, mesenteric lymph node (MLN), liver, and spleen were cultured. Only 8% of the PTA + CEF group had gram-negative bacteria in cecal culture vs 52% CEF, 84% PTA, and 100% in controls. Log Enterococcal colony counts were higher in the PTA + CEF group (8.0 + 0.9) vs controls (5.4 + 0.4) P less than 0.01. Translocation of Enterococcus to the MLN was significantly increased in the PTA + CEF group (67%) vs controls (0%) P less than 0.01. SBD effectively eliminates gram-negative organisms from the gut in the rat model. Overgrowth and translocation of Enterococcus suggests that infection with gram-positive organisms may be a limitation of SBD.

  13. Sepsis

    DEFF Research Database (Denmark)

    Perner, Anders; Gordon, Anthony C; De Backer, Daniel

    2016-01-01

    Sepsis is a major growing global burden and a major challenge to intensive care clinicians, researchers, guideline committee members and policy makers, because of its high and increasing incidence and great pathophysiological, molecular, genetic and clinical complexity. In spite of recent progress......, short-term mortality remains high and there is growing evidence of long-term morbidity and increased long-term mortality in survivors of sepsis both in developed and developing countries. Further improvement in the care of patients with sepsis will impact upon global health. In this narrative review...... and subsequent outcomes are to be improved in patients with sepsis....

  14. The Changing Role of the Clinical Microbiology Laboratory in Defining Resistance in Gram-negatives.

    Science.gov (United States)

    Endimiani, Andrea; Jacobs, Michael R

    2016-06-01

    The evolution of resistance in Gram-negatives has challenged the clinical microbiology laboratory to implement new methods for their detection. Multidrug-resistant strains present major challenges to conventional and new detection methods. More rapid pathogen identification and antimicrobial susceptibility testing have been developed for use directly on specimens, including fluorescence in situ hybridization tests, automated polymerase chain reaction systems, microarrays, mass spectroscopy, next-generation sequencing, and microfluidics. Review of these methods shows the advances that have been made in rapid detection of resistance in cultures, but limited progress in direct detection from specimens. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Epidemiology and molecular characterization of multidrug-resistant Gram-negative bacteria in Southeast Asia

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    Nuntra Suwantarat

    2016-05-01

    Full Text Available Abstract Background Multidrug-resistant Gram-negative bacteria (MDRGN, including extended-spectrum β-lactamases (ESBLs and multidrug-resistant glucose-nonfermenting Gram-negative bacilli (nonfermenters, have emerged and spread throughout Southeast Asia. Methods We reviewed and summarized current critical knowledge on the epidemiology and molecular characterization of MDRGN in Southeast Asia by PubMed searches for publications prior to 10 March 2016 with the term related to “MDRGN definition” combined with specific Southeast Asian country names (Thailand, Singapore, Malaysia, Vietnam, Indonesia, Philippines, Laos, Cambodia, Myanmar, Brunei. Results There were a total of 175 publications from the following countries: Thailand (77, Singapore (35, Malaysia (32, Vietnam (23, Indonesia (6, Philippines (1, Laos (1, and Brunei (1. We did not find any publications on MDRGN from Myanmar and Cambodia. We did not include publications related to Shigella spp., Salmonella spp., and Vibrio spp. and non-human related studies in our review. English language articles and abstracts were included for analysis. After the abstracts were reviewed, data on MDRGN in Southeast Asia from 54 publications were further reviewed and included in this study. Conclusions MDRGNs are a major contributor of antimicrobial-resistant bacteria in Southeast Asia. The high prevalence of ESBLs has been a major problem since 2005 and is possibly related to the development of carbapenem resistant organisms in this region due to the overuse of carbapenem therapy. Carbapenem–resistant Acinetobacter baumannii is the most common pathogen associated with nosocomial infections in this region followed by carbapenem-resistant Pseudomonas aeruginosa. Although Southeast Asia is not an endemic area for carbapenem-resistant Enterobacteriaceae (CRE, recently, the rate of CRE detection has been increasing. Limited infection control measures, lack of antimicrobial control, such as the presence of

  16. New transposon tools tailored for metabolic engineering of Gram-negative microbial cell factories

    Directory of Open Access Journals (Sweden)

    Esteban eMartínez-García

    2014-10-01

    Full Text Available Re-programming microorganisms to modify their existing functions and/or to bestow bacteria with entirely new-to-Nature tasks have largely relied so far on specialized molecular biology tools. Such endeavors are not only relevant in the burgeoning metabolic engineering arena, but also instrumental to explore the functioning of complex regulatory networks from a fundamental point of view. À la carte modification of bacterial genomes thus calls for novel tools to make genetic manipulations easier. We propose the use of a series of new broad-host-range mini-Tn5 vectors, termed pBAMDs, for the delivery of gene(s into the chromosome of Gram-negative bacteria and for generating saturated mutagenesis libraries in gene function studies. These delivery vectors endow the user with the possibility of easy cloning and subsequent insertion of functional cargoes with three different antibiotic resistance markers (kanamycin, streptomycin, and gentamicin. After validating the pBAMD vectors in the environmental bacterium Pseudomonas putida KT2440, their use was also illustrated by inserting the entire poly(3-hydroxybutyrate (PHB synthesis pathway from Cupriavidus necator in the chromosome of a phosphotransacetylase mutant of Escherichia coli. PHB is a completely biodegradable polyester with a number of industrial applications that make it attractive as a potential replacement of oil-based plastics. The non-selective nature of chromosomal insertions of the biosynthetic genes was evidenced by a large landscape of PHB synthesis levels in independent clones. One clone was selected and further characterized as a microbial cell factory for PHB accumulation, and it achieved polymer accumulation levels comparable to those of a plasmid-bearing recombinant. Taken together, our results demonstrate that the new mini-Tn5 vectors can be used to confer interesting phenotypes in Gram-negative bacteria that would be very difficult to engineer through direct manipulation of the

  17. New Transposon Tools Tailored for Metabolic Engineering of Gram-Negative Microbial Cell Factories

    Energy Technology Data Exchange (ETDEWEB)

    Martínez-García, Esteban; Aparicio, Tomás; Lorenzo, Víctor de; Nikel, Pablo I., E-mail: pablo.nikel@cnb.csic.es [Systems and Synthetic Biology Program, Centro Nacional de Biotecnología (CNB-CSIC), Madrid (Spain)

    2014-10-28

    Re-programming microorganisms to modify their existing functions and/or to bestow bacteria with entirely new-to-Nature tasks have largely relied so far on specialized molecular biology tools. Such endeavors are not only relevant in the burgeoning metabolic engineering arena but also instrumental to explore the functioning of complex regulatory networks from a fundamental point of view. À la carte modification of bacterial genomes thus calls for novel tools to make genetic manipulations easier. We propose the use of a series of new broad-host-range mini-Tn5-vectors, termed pBAMDs, for the delivery of gene(s) into the chromosome of Gram-negative bacteria and for generating saturated mutagenesis libraries in gene function studies. These delivery vectors endow the user with the possibility of easy cloning and subsequent insertion of functional cargoes with three different antibiotic-resistance markers (kanamycin, streptomycin, and gentamicin). After validating the pBAMD vectors in the environmental bacterium Pseudomonas putida KT2440, their use was also illustrated by inserting the entire poly(3-hydroxybutyrate) (PHB) synthesis pathway from Cupriavidus necator in the chromosome of a phosphotransacetylase mutant of Escherichia coli. PHB is a completely biodegradable polyester with a number of industrial applications that make it attractive as a potential replacement of oil-based plastics. The non-selective nature of chromosomal insertions of the biosynthetic genes was evidenced by a large landscape of PHB synthesis levels in independent clones. One clone was selected and further characterized as a microbial cell factory for PHB accumulation, and it achieved polymer accumulation levels comparable to those of a plasmid-bearing recombinant. Taken together, our results demonstrate that the new mini-Tn5-vectors can be used to confer interesting phenotypes in Gram-negative bacteria that would be very difficult to engineer through direct manipulation of the structural genes.

  18. Intrathecal or intraventricular therapy for post-neurosurgical Gram-negative meningitis: matched cohort study.

    Science.gov (United States)

    Shofty, B; Neuberger, A; Naffaa, M E; Binawi, T; Babitch, T; Rappaport, Z H; Zaaroor, M; Sviri, G; Paul, M

    2016-01-01

    Gram-negative post-operative meningitis due to carbapenem-resistant bacteria (CR-GNPOM) is a dire complication of neurosurgical procedures. We performed a nested propensity-matched historical cohort study aimed at examining the possible benefit of intrathecal or intraventricular (IT/IV) antibiotic treatment for CR-GNPOM. We included consecutive adults with GNPOM in two centres between 2005 and 2014. Patients receiving combined systemic and IT/IV treatment were matched to patients receiving systemic treatment only. Matching was done based on the propensity of the patients to receive IT/IV treatment. We compared patient groups with 30-day mortality defined as the primary outcome. The cohort included 95 patients with GNPOM. Of them, 37 received IT/IV therapy in addition to systemic treatment (22 with colistin and 15 with amikacin), mostly as initial therapy, through indwelling cerebrospinal fluid drains. Variables associated with IT/IV therapy in the propensity score included no previous neurosurgery, time from admission to meningitis, presence of a urinary catheter and GNPOM caused by carbapenem-resistant Gram-negative bacteria. Following propensity matching, 23 patients given IT/IV therapy and 27 controls were analysed. Mortality was significantly lower with IT/IV therapy: 2/23 (8.7%) versus 9/27 (33.3%), propensity-adjusted OR 0.19, 95% CI 0.04-0.99. Death or neurological deterioration at 30 days, 14-day and in-hospital mortality were lower with IT/IV therapy (OR <0.4 for all) without statistically significant differences. Among patients discharged alive, those receiving IT/IV therapy did not experience more neurological deterioration. Serious adverse events with IT/IV therapy were not documented. Our results support the early use of IT antibiotic treatment for CR-GNPOM when a delivery method is available. Copyright © 2015 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  19. New Transposon Tools Tailored for Metabolic Engineering of Gram-Negative Microbial Cell Factories

    International Nuclear Information System (INIS)

    Martínez-García, Esteban; Aparicio, Tomás; Lorenzo, Víctor de; Nikel, Pablo I.

    2014-01-01

    Re-programming microorganisms to modify their existing functions and/or to bestow bacteria with entirely new-to-Nature tasks have largely relied so far on specialized molecular biology tools. Such endeavors are not only relevant in the burgeoning metabolic engineering arena but also instrumental to explore the functioning of complex regulatory networks from a fundamental point of view. À la carte modification of bacterial genomes thus calls for novel tools to make genetic manipulations easier. We propose the use of a series of new broad-host-range mini-Tn5-vectors, termed pBAMDs, for the delivery of gene(s) into the chromosome of Gram-negative bacteria and for generating saturated mutagenesis libraries in gene function studies. These delivery vectors endow the user with the possibility of easy cloning and subsequent insertion of functional cargoes with three different antibiotic-resistance markers (kanamycin, streptomycin, and gentamicin). After validating the pBAMD vectors in the environmental bacterium Pseudomonas putida KT2440, their use was also illustrated by inserting the entire poly(3-hydroxybutyrate) (PHB) synthesis pathway from Cupriavidus necator in the chromosome of a phosphotransacetylase mutant of Escherichia coli. PHB is a completely biodegradable polyester with a number of industrial applications that make it attractive as a potential replacement of oil-based plastics. The non-selective nature of chromosomal insertions of the biosynthetic genes was evidenced by a large landscape of PHB synthesis levels in independent clones. One clone was selected and further characterized as a microbial cell factory for PHB accumulation, and it achieved polymer accumulation levels comparable to those of a plasmid-bearing recombinant. Taken together, our results demonstrate that the new mini-Tn5-vectors can be used to confer interesting phenotypes in Gram-negative bacteria that would be very difficult to engineer through direct manipulation of the structural genes.

  20. The resveratrol tetramer (--hopeaphenol inhibits type III secretion in the gram-negative pathogens Yersinia pseudotuberculosis and Pseudomonas aeruginosa.

    Directory of Open Access Journals (Sweden)

    Caroline E Zetterström

    Full Text Available Society faces huge challenges, as a large number of bacteria have developed resistance towards many or all of the antibiotics currently available. Novel strategies that can help solve this problem are urgently needed. One such strategy is to target bacterial virulence, the ability to cause disease e.g., by inhibition of type III secretion systems (T3SSs utilized by many clinically relevant gram-negative pathogens. Many of the antibiotics used today originate from natural sources. In contrast, most virulence-blocking compounds towards the T3SS identified so far are small organic molecules. A recent high-throughput screening of a prefractionated natural product library identified the resveratrol tetramer (--hopeaphenol as an inhibitor of the T3SS in Yersinia pseudotuberculosis. In this study we have investigated the virulence blocking properties of (--hopeaphenol in three different gram-negative bacteria. (--Hopeaphenol was found to have micromolar activity towards the T3SSs in Yersinia pseudotuberculosis and Pseudomonas aeruginosa in cell-based infection models. In addition (--hopeaphenol reduced cell entry and subsequent intracellular growth of Chlamydia trachomatis.

  1. Oral Gram-negative anaerobic bacilli as a reservoir of β-lactam resistance genes facilitating infections with multiresistant bacteria.

    Science.gov (United States)

    Dupin, Clarisse; Tamanai-Shacoori, Zohreh; Ehrmann, Elodie; Dupont, Anais; Barloy-Hubler, Frédérique; Bousarghin, Latifa; Bonnaure-Mallet, Martine; Jolivet-Gougeon, Anne

    2015-02-01

    Many β-lactamases have been described in various Gram-negative bacilli (Capnocytophaga, Prevotella, Fusobacterium, etc.) of the oral cavity, belonging to class A of the Ambler classification (CepA, CblA, CfxA, CSP-1 and TEM), class B (CfiA) or class D in Fusobacterium nucleatum (FUS-1). The minimum inhibitory concentrations of β-lactams are variable and this variation is often related to the presence of plasmids or other mobile genetic elements (MGEs) that modulate the expression of resistance genes. DNA persistence and bacterial promiscuity in oral biofilms also contribute to genetic transformation and conjugation in this particular microcosm. Overexpression of efflux pumps is facilitated because the encoding genes are located on MGEs, in some multidrug-resistant clinical isolates, similar to conjugative transposons harbouring genes encoding β-lactamases. All these facts lead us to consider the oral cavity as an important reservoir of β-lactam resistance genes and a privileged place for genetic exchange, especially in commensal strictly anaerobic Gram-negative bacilli. Copyright © 2014 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

  2. Computerized tomographic findings of hepatic fascioliasis compared with melioidosis-caused liver abscesses.

    Science.gov (United States)

    Chamadol, Nittaya; Laopaiboon, Vallop; Techasatian, Pennapa; Sukeepaisanjaroen, Wattana; Sripanuskul, Anan

    2010-07-01

    To compare the computerized tomographic (CT) findings of hepatic fascioliasis (HF) vs. melioidosis-caused liver (ML) abscesses. CT images of 15 patients with hepatic fascioliasis (HF) and 16 patients with melioidosis-caused liver (ML) abscesses were retrospectively reviewed. The authors evaluated and compared HF and ML abscesses (by chi2 and Fisher exact tests) vis-a-vis their location of liver involvement, size, shape, number margins, enhancement patterns, subcapsular lesions, internal architecture, dilatation of intrahepatic bile duct and combination with splenic abscesses. Fourteen HF patients had only liver abscesses and 1 had combined liver and splenic abscesses. Four ML patients had liver abscesses alone while 12 had combined liver and splenic abscesses (p = 0.000). Eight of the 15 HF (53.3%) and 2 of the 16 ML (12.5%) patients had subcapsular lesions (p = 0.019). The liver abscesses were round or oval with linear tracts in 8 of the 15 HF (53.3%) and none of the ML patients (p = 0.001). Between the respective HF and ML patients, there was a significant difference in those with round shaped in ML (p = 0.008), multiple and conglomerately distributed in HF (p = 0.050), multiple and discretely distributed in ML (p = 0.001) no (or minimal) peripheral contrast enhancement in HF (p = 0.011) and moderate or mark peripheral enhancement in ML (p = 0.011). The CT findings of liver abscesses that helped to differentiate hepatic fascioliasis from melioidosis liver abscesses were: their number shape, enhancement pattern, presence of subcapsular lesion (s) and co-occurrence with splenic abscesses. The diagnosis of hepatic fascioliasis by CT is suggested when the following characteristics were seen: (1) multiple, small round or oval (with linear tracts) conglomerates presenting as hypodense lesions; (2) no (or minimal) peripheral contrast enhancement; (3) subcapsular lesions; or (4) less frequent co-occurrence with splenic abscesses.

  3. Systemic inflammatory response syndrome criteria in defining severe sepsis.

    Science.gov (United States)

    Kaukonen, Kirsi-Maija; Bailey, Michael; Pilcher, David; Cooper, D Jamie; Bellomo, Rinaldo

    2015-04-23

    The consensus definition of severe sepsis requires suspected or proven infection, organ failure, and signs that meet two or more criteria for the systemic inflammatory response syndrome (SIRS). We aimed to test the sensitivity, face validity, and construct validity of this approach. We studied data from patients from 172 intensive care units in Australia and New Zealand from 2000 through 2013. We identified patients with infection and organ failure and categorized them according to whether they had signs meeting two or more SIRS criteria (SIRS-positive severe sepsis) or less than two SIRS criteria (SIRS-negative severe sepsis). We compared their characteristics and outcomes and assessed them for the presence of a step increase in the risk of death at a threshold of two SIRS criteria. Of 1,171,797 patients, a total of 109,663 had infection and organ failure. Among these, 96,385 patients (87.9%) had SIRS-positive severe sepsis and 13,278 (12.1%) had SIRS-negative severe sepsis. Over a period of 14 years, these groups had similar characteristics and changes in mortality (SIRS-positive group: from 36.1% [829 of 2296 patients] to 18.3% [2037 of 11,119], P<0.001; SIRS-negative group: from 27.7% [100 of 361] to 9.3% [122 of 1315], P<0.001). Moreover, this pattern remained similar after adjustment for baseline characteristics (odds ratio in the SIRS-positive group, 0.96; 95% confidence interval [CI], 0.96 to 0.97; odds ratio in the SIRS-negative group, 0.96; 95% CI, 0.94 to 0.98; P=0.12 for between-group difference). In the adjusted analysis, mortality increased linearly with each additional SIRS criterion (odds ratio for each additional criterion, 1.13; 95% CI, 1.11 to 1.15; P<0.001) without any transitional increase in risk at a threshold of two SIRS criteria. The need for two or more SIRS criteria to define severe sepsis excluded one in eight otherwise similar patients with infection, organ failure, and substantial mortality and failed to define a transition point in

  4. Antimicrobial Activities of Methanol, Ethanol and Supercritical CO2 Extracts of Philippine Piper betle L. on Clinical Isolates of Gram Positive and Gram Negative Bacteria with Transferable Multiple Drug Resistance.

    Directory of Open Access Journals (Sweden)

    Demetrio L Valle

    Full Text Available Piper betle L. has traditionally been used in alternative medicine in different countries for various therapeutic purposes, including as an anti-infective agent. However, studies reported in the literature are mainly on its activities on drug susceptible bacterial strains. This study determined the antimicrobial activities of its ethanol, methanol, and supercritical CO2 extracts on clinical isolates of multiple drug resistant bacteria which have been identified by the Infectious Disease Society of America as among the currently more challenging strains in clinical management. Assay methods included the standard disc diffusion method and the broth microdilution method for the determination of the minimum inhibitory concentration (MIC and the minimum bactericidal concentrations (MBC of the extracts for the test microorganisms. This study revealed the bactericidal activities of all the P. betle leaf crude extracts on methicillin-resistant Staphylococcus aureus (MRSA, vancomycin-resistant Enterococcus (VRE, extended spectrum β-lactamase-producing Enterobacteriaceae, carbapenem-resistant Enterobacteriaceae, and metallo-β-lactamase-producing Pseudomonas aeruginosa and Acinetobacter baumannii, with minimum bactericidal concentrations that ranged from 19μg/ml to 1250 μg/ml. The extracts proved to be more potent against the Gram positive MRSA and VRE than for the Gram negative test bacteria. VRE isolates were more susceptible to all the extracts than the MRSA isolates. Generally, the ethanol extracts proved to be more potent than the methanol extracts and supercritical CO2 extracts as shown by their lower MICs for both the Gram positive and Gram negative MDRs. MTT cytotoxicity assay showed that the highest concentration (100 μg/ml of P. betle ethanol extract tested was not toxic to normal human dermal fibroblasts (HDFn. Data from the study firmly established P. betle as an alternative source of anti-infectives against multiple drug resistant

  5. Antimicrobial Activities of Methanol, Ethanol and Supercritical CO2 Extracts of Philippine Piper betle L. on Clinical Isolates of Gram Positive and Gram Negative Bacteria with Transferable Multiple Drug Resistance.

    Science.gov (United States)

    Valle, Demetrio L; Cabrera, Esperanza C; Puzon, Juliana Janet M; Rivera, Windell L

    2016-01-01

    Piper betle L. has traditionally been used in alternative medicine in different countries for various therapeutic purposes, including as an anti-infective agent. However, studies reported in the literature are mainly on its activities on drug susceptible bacterial strains. This study determined the antimicrobial activities of its ethanol, methanol, and supercritical CO2 extracts on clinical isolates of multiple drug resistant bacteria which have been identified by the Infectious Disease Society of America as among the currently more challenging strains in clinical management. Assay methods included the standard disc diffusion method and the broth microdilution method for the determination of the minimum inhibitory concentration (MIC) and the minimum bactericidal concentrations (MBC) of the extracts for the test microorganisms. This study revealed the bactericidal activities of all the P. betle leaf crude extracts on methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), extended spectrum β-lactamase-producing Enterobacteriaceae, carbapenem-resistant Enterobacteriaceae, and metallo-β-lactamase-producing Pseudomonas aeruginosa and Acinetobacter baumannii, with minimum bactericidal concentrations that ranged from 19μg/ml to 1250 μg/ml. The extracts proved to be more potent against the Gram positive MRSA and VRE than for the Gram negative test bacteria. VRE isolates were more susceptible to all the extracts than the MRSA isolates. Generally, the ethanol extracts proved to be more potent than the methanol extracts and supercritical CO2 extracts as shown by their lower MICs for both the Gram positive and Gram negative MDRs. MTT cytotoxicity assay showed that the highest concentration (100 μg/ml) of P. betle ethanol extract tested was not toxic to normal human dermal fibroblasts (HDFn). Data from the study firmly established P. betle as an alternative source of anti-infectives against multiple drug resistant bacteria.

  6. Melioidosis in acute cholangitis of diabetic patient: a forgotten diagnosis

    OpenAIRE

    Mohamad, Nasir; Ponnusamy,Suresh; Devi,Sunita; Manikam,Rishya; Idrus,Ilya Irinaz; Hidayah Binti Abu Bakar,Nor

    2012-01-01

    Nasir Mohamad,1 Suresh Ponnusamy,2 Sunita Devi,3 Rishya Manikam,4 Ilya Irinaz Idrus,1 Nor Hidayah Abu Bakar51Department of Emergency Medicine, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Malaysia; 2AIMST University, Bedong, Malaysia; 3Hospital Sultan Abdul Halim, Sungai Petani, Malaysia; 4University Malaya Medical Centre, Kuala Lumpur, Malaysia; 5Department of Pathology, Hospital Raja Perempuan Zainab II, Kota Bharu, MalaysiaAbstract: Melioidosis presents with a wide...

  7. Motuporamine Derivatives as Antimicrobial Agents and Antibiotic Enhancers against Resistant Gram-Negative Bacteria.

    Science.gov (United States)

    Borselli, Diane; Blanchet, Marine; Bolla, Jean-Michel; Muth, Aaron; Skruber, Kristen; Phanstiel, Otto; Brunel, Jean Michel

    2017-02-01

    Dihydromotuporamine C and its derivatives were evaluated for their in vitro antimicrobial activities and antibiotic enhancement properties against Gram-negative bacteria and clinical isolates. The mechanism of action of one of these derivatives, MOTU-N44, was investigated against Enterobacter aerogenes by using fluorescent dyes to evaluate outer-membrane depolarization and permeabilization. Its efficiency correlated with inhibition of dye transport, thus suggesting that these molecules inhibit drug transporters by de-energization of the efflux pump rather than by direct interaction of the molecule with the pump. This suggests that depowering the efflux pump provides another strategy to address antibiotic resistance. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  8. Antimicrobial effects of zero-valent iron nanoparticles on gram-positive Bacillus strains and gram-negative Escherichia coli strains

    Directory of Open Access Journals (Sweden)

    Yi-Huang Hsueh

    2017-11-01

    Full Text Available Abstract Background Zero-valent iron nanoparticles (ZVI NPs have been used extensively for the remediation of contaminated soil and groundwater. Owing to their large active surface area, they serve as strong and effective reductants. However, the ecotoxicity and bioavailability of ZVI NPs in diverse ecological media have not been evaluated in detail and most studies have focused on non-nano ZVI or Fe0. In addition, the antimicrobial properties of ZVI NPs have rarely been investigated, and the underlying mechanism of their toxicity remains unknown. Results In the present study, we demonstrate that ZVI NPs exhibited significant toxicity at 1000 ppm against two distinct gram-positive bacterial strains (Bacillus subtilis 3610 and Bacillus thuringiensis 407 but not against two gram-negative strains (Escherichia coli K12 and ATCC11634. Specifically, ZVI NPs caused at least a 4-log and 1-log reductions in cell numbers, respectively, in the two Bacillus strains, whereas no change was detected in the two E. coli strains. X-ray photoelectron spectroscopy, X-ray absorption near-edge, and extended X-ray absorption fine structure spectra confirmed that Bacillus cells exposed to ZVI NPs contained mostly Fe2O3 with some detectable FeS. This finding indicated that Fe0 nanoparticles penetrated the bacterial cells, where they were subsequently oxidized to Fe2O3 and FeS. RedoxSensor analysis and propidium iodide (PI staining showed decreased reductase activity and increased PI in both Bacillus strains treated with a high (1000 ppm concentration of ZVI NPs. Conclusion Taken together, these data show that the toxicity of ZVI NPs was derived from their oxidative properties, which may increase the levels of reactive oxygen species and lead to cell death.

  9. Antimicrobial susceptibility of Gram-negative bacteria causing intra-abdominal infections in China: SMART China 2011.

    Science.gov (United States)

    Zhang, Hui; Yang, Qiwen; Xiao, Meng; Chen, Minjun; Badal, Robert E; Xu, Yingchun

    2014-01-01

    The Study for Monitoring Antimicrobial Resistance Trends program monitors the activity of antibiotics against aerobic and facultative Gram-negative bacilli (GNBs) from intra-abdominal infections (IAIs) in patients worldwide. In 2011, 1 929 aerobic and facultative GNBs from 21 hospitals in 16 cities in China were collected. All isolates were tested using a panel of 12 antimicrobial agents, and susceptibility was determined following the Clinical Laboratory Standards Institute guidelines. Among the Gram-negative pathogens causing IAIs, Escherichia coli (47.3%) was the most commonly isolated, followed by Klebsiella pneumoniae (17.2%), Pseudomonas aeruginosa (10.1%), and Acinetobacter baumannii (8.3%). Enterobacteriaceae comprised 78.8% (1521/1929) of the total isolates. Among the antimicrobial agents tested, ertapenem and imipenem were the most active agents against Enterobacteriaceae, with susceptibility rates of 95.1% and 94.4%, followed by amikacin (93.9%) and piperacillin/tazobactam (87.7%). Susceptibility rates of ceftriaxone, cefotaxime, ceftazidime, and cefepime against Enterobacteriaceae were 38.3%, 38.3%, 61.1%, and 50.8%, respectively. The leastactive agent against Enterobacteriaceae was ampicillin/sulbactam (25.9%). The extended-spectrum β-lactamase (ESBL) rates among E. coli, K. pneumoniae, Klebsiella oxytoca, and Proteus mirabilis were 68.8%, 38.1%, 41.2%, and 57.7%, respectively. Enterobacteriaceae were the major pathogens causing IAIs, and the most active agents against the study isolates (including those producing ESBLs) were ertapenem, imipenem, and amikacin. Including the carbapenems, most agents exhibited reduced susceptibility against ESBL-positive and multidrug-resistant isolates.

  10. [Continuous surveillance of antimicrobial resistance among nosocomial gram-negative bacilli from intensive care units in China].

    Science.gov (United States)

    Chen, Min-Jun; Wang, Hui

    2003-03-10

    To investigate the change of antimicrobial resistance among nosocomial gram-negative bacilli, especially those of Enterobacteriaceae isolated from intensive care units from 1994 to 2001 in China. E test was made to determine the minimal inhibitory concentrations (MIC) of 10 279 isolates of gram-negative bacilli (including 5 829 strains of bacilli of Enterobacteriaceae) from 32 hospitals in China from 1994 to 2001. The most common pathogens were Pseudomonas aeruginosa; Escherichia coli, Klebsiella spp, Acinetobacter spp. Enterobacter spp, and Stenotrophomonas maltophilia. The most common pathogens in respiratory tract specimens were Pseudomonas aeruginosa (25%), Klebsiella pneumoniae (18%), and Acinetobacter baumanni (11%). The most common pathogens in blood and urine specimens were Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The antibiotic remaining the most active against all of the gram-negative bacilli for 7 years was imipenem (with a susceptibility rate of 87%), followed by cefoperazone/sulbactam (however, with a susceptibility rate decreasing from 86% to 75%), amikacin (75%), ceftazidime (73%), cefepime (72%), and piperacillin/tazobactam (71%). The susceptibility rate of Escherichia coli Klebsiella pneumoniae to imipenem remained 98% with a MIC(90) of 0.5 micro g/ml during the 7 years, much higher than those to amikacin (84%), ceftazidime (83%), cefoperazone/sulbactam (83%), piperacillin/tazobactam (80%), and cefepime (80%). The susceptibility rate of these two species to cefoperazone/sulbactam decreased from 90% in 1996 to 74% in 2001. While the susceptibility to cefotaxime and ceftriaxone decreased from 82% to 57%. The susceptibility rate of Escherichia coli to ciprofloxacin decreased from 54% to 25% and that of Klebsiella pneumoniae to ciprofloxacin decreased from 90% to 75%. The prevalence of extended spectrum beta-lactamases in these two species increased from 11% in 1994 to 34% in 2001. The most active antibiotics against

  11. Fastidious Gram-Negatives: Identification by the Vitek 2 Neisseria-Haemophilus Card and by Partial 16S rRNA Gene Sequencing Analysis

    DEFF Research Database (Denmark)

    Wolff Sönksen, Ute; Christensen, Jens Jørgen; Nielsen, Lisbeth

    2010-01-01

    Taxonomy and identification of fastidious Gram negatives are evolving and challenging. We compared identifications achieved with the Vitek 2 Neisseria-Haemophilus (NH) card and partial 16S rRNA gene sequence (526 bp stretch) analysis with identifications obtained with extensive phenotypic...... characterization using 100 fastidious Gram negative bacteria. Seventy-five strains represented 21 of the 26 taxa included in the Vitek 2 NH database and 25 strains represented related species not included in the database. Of the 100 strains, 31 were the type strains of the species. Vitek 2 NH identification...... results: 48 of 75 database strains were correctly identified, 11 strains gave `low discrimination´, seven strains were unidentified, and nine strains were misidentified. Identification of 25 non-database strains resulted in 14 strains incorrectly identified as belonging to species in the database. Partial...

  12. Temperature shock, injury and transient sensitivity to nisin in Gram negatives.

    Science.gov (United States)

    Boziaris, I S; Adams, M R

    2001-10-01

    The effect of thermal stresses on survival, injury and nisin sensitivity was investigated in Salmonella Enteritidis PT4, PT7 and Pseudomonas aeruginosa. Heating at 55 degrees C, rapid chilling to 0.5 degrees C or freezing at -20 degrees C produced transient sensitivity to nisin. Cells were only sensitive if nisin was present during stress. Resistance recovered rapidly afterwards, though some cells displayed residual injury. Injury was assessed by SDS sensitivity, hydrophobicity changes, lipopolysaccharide release and NPN uptake. LPS release and hydrophobicity were not always associated with transient nisin sensitivity. Uptake of NPN correlated better but persisted longer after treatment. Thermal shocks produce transient injury to the outer membrane, allowing nisin access. After treatment, the permeability barrier is rapidly restored by a process apparently involving reorganization rather than biosynthetic repair. Inclusion of nisin during food treatments that impose sub-lethal stress on Gram negatives could increase process lethality, enhancing microbiological safety and stability.

  13. Add-On Therapy with Ertapenem in Infections with Multidrug Resistant Gram-Negative Bacteria: Pediatric Experience

    Directory of Open Access Journals (Sweden)

    Sevgen Tanır Basaranoglu

    2017-01-01

    Full Text Available Optimal therapy for infections with carbapenem resistant GNB is not well established due to the weakness of data. Patients presenting with bloodstream infections caused by multidrug resistant Klebsiella pneumoniae were treated with a combination treatment. Optimal therapy for infections with carbapenem resistant Gram-negative bacteria is a serious problem in pediatric patients. We presented three cases who were successfully treated with addition of ertapenem to the combination treatment for bacteremia with multidrug resistant Klebsiella pneumoniae. Dual carbapenem treatment approach is a new approach for these infections and requires more data in children.

  14. Decreased ADAMTS 13 Activity is Associated With Disease Severity and Outcome in Pediatric Severe Sepsis

    Science.gov (United States)

    Lin, Jainn-Jim; Chan, Oi-Wa; Hsiao, Hsiang-Ju; Wang, Yu; Hsia, Shao-Hsuan; Chiu, Cheng-Hsun

    2016-01-01

    Abstract Decreased ADAMTS 13 activity has been reported in severe sepsis and in sepsis-induced disseminated intravascular coagulation. This study aimed to investigate the role of ADAMTS 13 in different pediatric sepsis syndromes and evaluate its relationship with disease severity and outcome. We prospectively collected cases of sepsis treated in a pediatric intensive care unit, between July 2012 and June 2014 in Chang Gung Children's Hospital in Taoyuan, Taiwan. Clinical characteristics and ADAMTS-13 activity were analyzed. All sepsis syndromes had decreased ADAMTS 13 activity on days 1 and 3 of admission compared to healthy controls. Patients with septic shock had significantly decreased ADAMTS 13 activity on days 1 and 3 compared to those with sepsis and severe sepsis. There was a significant negative correlation between ADAMTS 13 activity on day 1 and day 1 PRISM-II, PELOD, P-MOD, and DIC scores. Patients with mortality had significantly decreased ADAMTS 13 activity on day 1 than survivors, but not on day 3. Different pediatric sepsis syndromes have varying degrees of decreased ADAMTS 13 activity. ADAMTS 13 activity is strongly negatively correlated with disease severity of pediatric sepsis syndrome, whereas decreased ADAMTS 13 activity on day 1 is associated with increased risk of mortality. PMID:27100422

  15. Evaluation of Inhibitory and Lethal Effects of Aqueous, Ethanolic and Hydroalcoholic Extracts of Aerial Parts of Salvia chorassanica against Some Gram-negative and Gram-positive Bacteria in Vitro

    Directory of Open Access Journals (Sweden)

    Azam Mehraban

    2016-05-01

    Full Text Available Abstract Background and Objectives: Development of bacterial resistance to antibiotics has led to an increased tendency to development of new more effective and non-toxic antimicrobial compounds. In this study, the inhibitory and lethal effects of aqueous, ethanolic, and hydroalcoholic extracts of aerial parts of Salvia chorassanica were evaluated against Listeria monocytogenes, Bacillus cereus, Salmonella typhi, and Escherichia coli O:157. Methods: In this study, Kirby–Bauer disk diffusion method was used to evaluate antimicrobial activity. In this method, bacteria were cultivated as grass culture in Mueller Hinton Agar (MHA media. To determine the minimum inhibitory concentration and minimum bactericidal concentration, micro-dilution method with ELISA and addition of phenyl tetrazolium chloride reagent, were used. Data were analyzed using one-way ANOVA and Duncan’s test at the significance level of p<0.05. Results: The highest diameter of inhibition in agar diffusion method was related to hydroalcoholic extract of aerial parts of Salvia chorassanica against Gram-positive bacteria Bacillus cereus. The amount of calculated MIC of hydro-alcoholic extract for Gram-positive bacteria was 30mg/ml. This amount was the lowest among other measured MIC. Conclusion: Based on the results of this study, Gram-negative bacteria showed more resistance to different extracts of aerial parts of Salvia chorassanica as compared to Gram-positive bacteria, so that Salmonella typhi was found to be the most resistant bacterium among the tested bacteria.

  16. Gram staining apparatus for space station applications

    Science.gov (United States)

    Molina, T. C.; Brown, H. D.; Irbe, R. M.; Pierson, D. L.

    1990-01-01

    A self-contained, portable Gram staining apparatus (GSA) has been developed for use in the microgravity environment on board the Space Station Freedom. Accuracy and reproducibility of this apparatus compared with the conventional Gram staining method were evaluated by using gram-negative and gram-positive controls and different species of bacteria grown in pure cultures. A subsequent study was designed to assess the performance of the GSA with actual specimens. A set of 60 human and environmental specimens was evaluated with the GSA and the conventional Gram staining procedure. Data obtained from these studies indicated that the GSA will provide the Gram staining capability needed for the microgravity environment of space.

  17. Antiseptic and antibiotic resistance in Gram-negative bacteria causing urinary tract infection.

    Science.gov (United States)

    Stickler, D J; Thomas, B

    1980-01-01

    A collection of 802 isolates of Gram-negative bacteria causing urinary tract infections was made from general practice, antenatal clinics, and local hospitals. The organisms were tested for their sensitivity to chlorhexidine, cetrimide, glutaraldehyde, phenyl mercuric nitrate, a phenolic formulation, and a proprietary antiseptic containing a mixture of picloxydine, octyl phenoxy polyethoxyethanol, and benzalkonium chloride. Escherichia coli, the major species isolated, proved to be uniformly sensitive to these agents. Approximately 10% of the total number of isolates, however, exhibited a degree of resistance to the cationic agents. These resistant organisms were members of the genera Proteus, Providencia, and Pseudomonas; they were also generally resistant to five, six, or seven antibiotics. It is proposed therefore that an antiseptic policy which involves the intensive use of cationic antiseptics might lead to the selection of a flora of notoriously drug-resistant species. PMID:6769972

  18. Sepsis (For Parents)

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Sepsis KidsHealth / For Parents / Sepsis What's in this article? ... When to Call the Doctor Print What Is Sepsis? Sepsis is when the immune system responds to ...

  19. Plasmid-Mediated Antibiotic Resistance and Virulence in Gram-negatives: the Klebsiella pneumoniae Paradigm.

    Science.gov (United States)

    Ramirez, Maria S; Traglia, German M; Lin, David L; Tran, Tung; Tolmasky, Marcelo E

    Plasmids harbor genes coding for specific functions including virulence factors and antibiotic resistance that permit bacteria to survive the hostile environment found in the host and resist treatment. Together with other genetic elements such as integrons and transposons, and using a variety of mechanisms, plasmids participate in the dissemination of these traits resulting in the virtual elimination of barriers among different kinds of bacteria. In this article we review the current information about physiology and role in virulence and antibiotic resistance of plasmids from the gram-negative opportunistic pathogen Klebsiella pneumoniae . This bacterium has acquired multidrug resistance and is the causative agent of serious communityand hospital-acquired infections. It is also included in the recently defined ESKAPE group of bacteria that cause most of US hospital infections.

  20. Burdock (Arctium lappa Leaf Extracts Increase the In Vitro Antimicrobial Efficacy of Common Antibiotics on Gram-positive and Gram-negative Bacteria

    Directory of Open Access Journals (Sweden)

    Pirvu Lucia

    2017-04-01

    Full Text Available This work aimed to study the potential effects of four Arctii folium extracts, 5 mg gallic [GAE] acid equivalents per 1 mL sample, on six antibiotics (Ampicillin/AM, Tetracycline/TE, Ciprofloxacin/CIP, Sulfamethoxazole-Trimethoprim/SXT, Chloramphenicol/C and Gentamicin/CN tested on four Gram-positive (Staphylococcus aureus ATCC 6538, Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, and Staphylococcus epidermidis ATCC 12228 and five Gram-negative (Proteus mirabilis ATCC 29245, Escherichia coli ATCC 35218, E. coli ATCC 11229, E. coli ATCC 8739, and Bacillus cereus ATCC 11778 bacteria. Arctii folium extracts were the whole ethanol extract/W and subsequent ethyl acetate/EA, aqueous/AQ, and chloroform/CHL fractions. Chemical qualitative analysis (HPTLC method emphasized five main polyphenol compounds in Arctii folium polar extracts: chlorogenic acid (Rf≈0.52/0.55 and its isomer, 1,5-di-O-caffeoylquinic acid (Rf≈0.90/0.92, plus cynarin (Rf≈0.77, hyperoside (Rf≈0.68/0.64 and isoquercitrin (Rf≈0.69/0.71. Microbiological screening indicated Arctii folium polar extracts (AQ and W efficacy on S. epidermidis ATCC 12228; the MIC values were in the range of common antibiotics, being 32 and 128 μg GAE per mL sample respectively. The unpredictable effects (stimulatory or inhibitory of Arctii folium extracts in combination with typical antibiotics as well as a potential use of the whole ethanol extract/W for restoring the antimicrobial potency of susceptible antibiotics have also been evidenced.

  1. Sepsis due to clostridium septicum: case report

    International Nuclear Information System (INIS)

    Foga, M.M.; McGinn, G.J.; Kroeker, M.A.; Guzman, R.

    2000-01-01

    Clostridium septicum is an unusual anaerobic, gram-positive, gas-producing bacillus, which has been identified as a cause of fulminant rapidly fatal infection in humans. Infection with C. septicum usually occurs in patients with cancer, patients receiving immunosuppressive chemotherapy, or patients with a nonmalignant hematological disorder such as hemolytic uremic syndrome. C. septicum infection most commonly involves the abdomen, and a recent review article has identified 164 cases in the medical literature describing the abdominal findings in this disease. Intracranial manifestation of C. septicum infection are less common and include meningitis, cerebritis, abscess formation and pneumocephalus. There have been only 12 documented cases in the English literature describing central nervous system lesions associated with C. septicum. We present a case report of a 56-year-old man in whom septicemia due to C. septicum developed as a complication of Crohn's disease. To our knowledge, there has never been a previous report of C. septicum sepsis related to underlying Crohn's disease. Our case is also remarkable in that an intracerebral gas collection developed at the site of a mycotic infarct related to C. septicum bacteremia, Intracranial, intraparenchymal gas formation related to anaerobic infection is extremely rare; to our knowledge, this radiological finding related to C. septicum sepsis has been described in only 1 previous case report in the medical literature. We also describe the intra-abdominal manifestations of C. septicum sepsis that occurred in this patient as well as the associated radiographic and pathologic findings. (author)

  2. Cues and regulatory pathways involved in natural competence and transformation in pathogenic and environmental Gram-negative bacteria.

    Science.gov (United States)

    Seitz, Patrick; Blokesch, Melanie

    2013-05-01

    Bacterial genomics is flourishing, as whole-genome sequencing has become affordable, readily available and rapid. As a result, it has become clear how frequently horizontal gene transfer (HGT) occurs in bacteria. The potential implications are highly significant because HGT contributes to several processes, including the spread of antibiotic-resistance cassettes, the distribution of toxin-encoding phages and the transfer of pathogenicity islands. Three modes of HGT are recognized in bacteria: conjugation, transduction and natural transformation. In contrast to the first two mechanisms, natural competence for transformation does not rely on mobile genetic elements but is driven solely by a developmental programme in the acceptor bacterium. Once the bacterium becomes competent, it is able to take up DNA from the environment and to incorporate the newly acquired DNA into its own chromosome. The initiation and duration of competence differ significantly among bacteria. In this review, we outline the latest data on representative naturally transformable Gram-negative bacteria and how their competence windows differ. We also summarize how environmental cues contribute to the initiation of competence in a subset of naturally transformable Gram-negative bacteria and how the complexity of the niche might dictate the fine-tuning of the competence window. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  3. Detection of AmpC β lactamases in gram-negative bacteria

    Directory of Open Access Journals (Sweden)

    Gunjan Gupta

    2014-01-01

    Full Text Available Amp C β-lactamases are clinically important cephalosporinases encoded on the chromosomes of many Enterobacteriaceae and a few other organisms, where they mediate resistance to cephalothin, cefazolin, cefoxitin, most penicillins, and β-lactamase inhibitor/β-lactam combinations. The increase in antibiotic resistance among Gram-negative bacteria is a notable example of how bacteria can procure, maintain and express new genetic information that can confer resistance to one or several antibiotics. Detection of organisms producing these enzymes can be difficult, because their presence does not always produce a resistant phenotype on conventional disc diffusion or automated susceptibility testing methods. These enzymes are often associated with potentially fatal laboratory reports of false susceptibility to β-lactams phenotypically. With the world-wide increase in the occurrence, types and rate of dissemination of these enzymes, their early detection is critical. AmpC β-lactamases show tremendous variation in geographic distribution. Thus, their accurate detection and characterization are important from epidemiological, clinical, laboratory, and infection control point of view. This document describes the methods for detection for AmpC β-lactamases, which can be adopted by routine diagnostic laboratories.

  4. A possible alternative to the error prone modified Hodge test to correctly identify the carbapenemase producing Gram-negative bacteria.

    Science.gov (United States)

    Jeremiah, S S; Balaji, V; Anandan, S; Sahni, R D

    2014-01-01

    The modified Hodge test (MHT) is widely used as a screening test for the detection of carbapenemases in Gram-negative bacteria. This test has several pitfalls in terms of validity and interpretation. Also the test has a very low sensitivity in detecting the New Delhi metallo-β-lactamase (NDM). Considering the degree of dissemination of the NDM and the growing pandemic of carbapenem resistance, a more accurate alternative test is needed at the earliest. The study intends to compare the performance of the MHT with the commercially available Neo-Sensitabs - Carbapenemases/Metallo-β-Lactamase (MBL) Confirmative Identification pack to find out whether the latter could be an efficient alternative to the former. A total of 105 isolates of Klebsiella pneumoniae resistant to imipenem and meropenem, collected prospectively over a period of 2 years were included in the study. The study isolates were tested with the MHT, the Neo-Sensitabs - Carbapenemases/MBL Confirmative Identification pack and polymerase chain reaction (PCR) for detecting the blaNDM-1 gene. Among the 105 isolates, the MHT identified 100 isolates as carbapenemase producers. In the five isolates negative for the MHT, four were found to produce MBLs by the Neo-Sensitabs. The Neo-Sensitabs did not have any false negatives when compared against the PCR. The MHT can give false negative results, which lead to failure in detecting the carbapenemase producers. Also considering the other pitfalls of the MHT, the Neo-Sensitabs--Carbapenemases/MBL Confirmative Identification pack could be a more efficient alternative for detection of carbapenemase production in Gram-negative bacteria.

  5. Management of the open abdomen using negative pressure wound therapy with instillation in severe abdominal sepsis: A review of 48 cases in Hospital Mexico, Costa Rica.

    Science.gov (United States)

    Sibaja, Pablo; Sanchez, Alfredo; Villegas, Guillermo; Apestegui, Alvaro; Mora, Esteban

    2017-01-01

    Despite the numerous advances in recent years, severe abdominal sepsis (with associated organ failure associated with infection) remains a serious, life-threatening condition with a high mortality rate. OA is a viable alternative to the previously used scheduled repeat laparotomy or continuous peritoneal lavage. The use of Negative Pressure Wound Therapy (NPWT) has been described as a successful method of management of the open abdomen. Adding instillation of saline solution to NPWT in a programmed and controlled manner, could offer the clinician an additional tool for the management of complex septic abdomen. To explore if the concept of active two-way therapy (Negative pressure wound therapy with instillation or NPWT-I) yields superior control of underlying, life-threatening abdominal infections and its effects on survival and morbidity in patients with severe abdominal sepsis when management with an open abdomen is required. A retrospective review of 48 patients with severe abdominal sepsis, who were managed with and open abdomen and NPWT-I was performed. NPWT-I was initiated utilizing the same parameters on all patients, this consisted of cycles of instillation of saline solution, which was removed through negative pressure after a short dwell period. We observed the effects on primary fascia closure rate, mortality, hospital and SICU length of stay and associated complications. Our patient group consisted of 20 (42%) males and 28 (58%) females. Average age was 48 years. Mortality in these patients was attributed to pulmonary embolism (n=1), acute renal failure (n=2) and cardiopulmonary arrest (n=1). Average total hospital stay was 24days, and stay in the SICU (n=26) averaged 7.5days. No acute complications related to the NPWT-I. All patients presenting with abdominal compartment syndrome resolved after initiation of the NPWT-I. A total of 46 patients (96%) patients achieved fascia closure after NPWT-I therapy after an average of 6days. Four patients (8%) died

  6. Sepsis

    Science.gov (United States)

    ... mild sepsis, but the mortality rate for septic shock is nearly 50 percent. Also, an episode of severe sepsis may ... of Nondiscrimination Advertising Mayo Clinic is a not-for-profit organization ...

  7. Alternate gram staining technique using a fluorescent lectin.

    Science.gov (United States)

    Sizemore, R K; Caldwell, J J; Kendrick, A S

    1990-01-01

    Fluorescence-labeled wheat germ agglutinin binds specifically to N-acetylglucosamine in the outer peptidoglycan layer of gram-positive bacteria. The peptidoglycan layer of gram-negative bacteria is covered by a membrane and is not labeled by the lectin. By exploiting this phenomenon, an alternative Gram staining technique has been developed. Images PMID:1697149

  8. Antibiofilm effect of Nocardiopsis sp. GRG 1 (KT235640) compound against biofilm forming Gram negative bacteria on UTIs.

    Science.gov (United States)

    Rajivgandhi, Govindan; Vijayan, Ramachandran; Maruthupandy, Muthuchamy; Vaseeharan, Baskaralingam; Manoharan, Natesan

    2018-05-01

    Urinary tract infections (UTIs) are diverse public health complication and caused by range of pathogens, however mostly Gram negative bacteria cause significant life threatening risks to different populations. The prevalence rate and antimicrobial resistance among the Gram negative uropathogens alarmed significantly heighten the economic burden of these infections. In this study, we investigated the antibiofilm efficiency of Pyrrolo [1,2-a] pyrazine-1,4-dione,hexahydro-3-(2-methylpropyl) extracted from endophytic actinomycetes Nocardiopsis sp. GRG 1 (KT235640) against P. mirabilis and E. coli. The extracted compound was characterized through TLC, HPLC, GC-MS, LC-MS and confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM). The compound, Pyrrolo [1,2-a] pyrazine-1, 4-dione, hexahydro-3-(2-methylpropyl) inhibits both bacterial biofilm formation as well as reduces the viability of preformed biofilms. Furthermore, CLSM image shows cell shrinkage, disorganized cell membrane and loss of viability. The SEM result also confirms the cell wall degradation in treated cells of the bacteria. Hence, the Pyrrolo [1,2-a]pyrazine-1,4-dione, hexahydro-3-(2-methylpropyl) is active against P. mirabilis and E. coli. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Competitive binding of polyethyleneimine-coated gold nanoparticles to enzymes and bacteria: a key mechanism for low-level colorimetric detection of gram-positive and gram-negative bacteria

    International Nuclear Information System (INIS)

    Thiramanas, Raweewan; Laocharoensuk, Rawiwan

    2016-01-01

    The article describes a simple and rapid method for colorimetric detection of bacteria. It is based on competitive binding of positively charged polyethyleneimine-coated gold nanoparticles (PEI-AuNPs) to negatively charged enzymes and bacteria. The PEI-AuNPs are electrostatically attracted by both the bacterial surface and the enzyme β-galactosidase (β-Gal). Binding to the latter results in the inhibition of enzyme activity. However, in the presence of a large number of bacteria, the PEI-AuNPs preferentially bind to bacteria. Hence, the enzyme will not be inhibited and its activity can be colorimetrically determined via hydrolysis of the chromogenic substrate chlorophenol red β-D-galactopyranoside (CPRG). The detection limit of this assay is as low as 10 cfu·mL −1 , and the linear range extends from 10 6 to 10 8 cfu·mL −1 . The assay is applicable to both Gram-negative (such as enterotoxigenic Escherichia coli; ETEC) and Gram-positive (Staphylococcus aureus; S. aureus) bacteria. Results are obtained within 10 min using an optical reader, and within 2–3 h by bare-eye detection. The method was applied to the identification of ETEC contamination at a level of 10 cfu·mL −1 in spiked drinking water. Given its low detection limit and rapidity (sample preconcentration is not required), this method holds great promise for on-site detection of total bacterial contamination. (author)

  10. Incidence, risk factors and clinical epidemiology of melioidosis: a complex socio-ecological emerging infectious disease in the Alor Setar region of Kedah, Malaysia

    Directory of Open Access Journals (Sweden)

    Vijayalakshmi Natesan

    2010-10-01

    Full Text Available Abstract Background Melioidosis, a severe and fatal infectious disease caused by Burkholderia pseudomallei, is believed to an emerging global threat. However, data on the natural history, risk factors, and geographic epidemiology of the disease are still limited. Methods We undertook a retrospective analysis of 145 confirmed cases extracted from a hospital-based Melioidosis Registry set up from 2005 in Hospital Sultanah Bahiyah, Alor Setar, Kedah state, Malaysia, in order to provide a first description of the contemporary incidence, risk factors, and clinical epidemiology of the disease in this putatively high risk region of the country. Results The incidence of melioidosis in Alor Setar is remarkably high at 16.35 per 100,000 population per year. The mean age of patients was 50.40 years, with infection varying nonlinearly with age. Males (75.2%; P 2 = 30.57, P Conclusions Melioidosis represents a complex socio-ecological public health problem in Kedah, being strongly related with age, occupation, rainfall and predisposing chronic diseases, such as diabetes mellitus. Among cases, bacteremic patients were associated with significantly high mortality despite provision of the recommended antibacterial therapy. The burden of this disease is likely to grow in this region unless better informed interventions targeted at high-risk groups and associated diseases are urgently implemented.

  11. Third generation cephalosporin resistant Enterobacteriaceae and multidrug resistant gram-negative bacteria causing bacteremia in febrile neutropenia adult cancer patients in Lebanon, broad spectrum antibiotics use as a major risk factor, and correlation with poor prognosis

    Directory of Open Access Journals (Sweden)

    Rima eMoghnieh

    2015-02-01

    Full Text Available Bacteremia remains a major cause of life-threatening complications in patients receiving anticancer chemotherapy. The spectrum and susceptibility profiles of causative microorganisms differ with time and place. Data from Lebanon are scarce. We aim at evaluating the epidemiology of bacteremia in cancer patients in a university hospital in Lebanon, emphasizing antibiotic resistance and risk factors of multi-drug resistant organism (MDRO-associated bacteremia.This is a retrospective study of 75 episodes of bacteremia occurring in febrile neutropenic patients admitted to the hematology-oncology unit at Makassed General Hospital, Lebanon, from October 2009-January 2012.It corresponds to epidemiological data on bacteremia episodes in febrile neutropenic cancer patients including antimicrobial resistance and identification of risk factors associated with third generation cephalosporin resistance (3GCR and MDRO-associated bacteremia. Out of 75 bacteremias, 42.7% were gram-positive (GP, and 57.3% were gram-negative (GN. GP bacteremias were mostly due to methicillin-resistant coagulase negative staphylococci (28% of total bacteremias and 66% of GP bacteremias. Among the GN bacteremias, Escherichia coli (22.7% of total, 39.5% of GN organisms and Klebsiellapneumoniae(13.3% of total, 23.3% of GN organisms were the most important causative agents. GN bacteremia due to 3GC sensitive (3GCS bacteria represented 28% of total bacteremias, while 29% were due to 3GCR bacteria and 9% were due to carbapenem-resistant organisms. There was a significant correlation between bacteremia with MDRO and subsequent intubation, sepsis and mortality. Among potential risk factors, only broad spectrum antibiotic intake >4 days before bacteremia was found to be statistically significant for acquisition of 3GCR bacteria. Using carbapenems or piperacillin/ tazobactam>4 days before bacteremia was significantly associated with the emergence of MDRO (p value<0.05.

  12. Studies on tridecaptin B(1), a lipopeptide with activity against multidrug resistant Gram-negative bacteria.

    Science.gov (United States)

    Cochrane, Stephen A; Lohans, Christopher T; van Belkum, Marco J; Bels, Manon A; Vederas, John C

    2015-06-07

    Previously other groups had reported that Paenibacillus polymyxa NRRL B-30507 produces SRCAM 37, a type IIA bacteriocin with antimicrobial activity against Campylobacter jejuni. Genome sequencing and isolation of antimicrobial compounds from this P. polymyxa strain show that the antimicrobial activity is due to polymyxins and tridecaptin B1. The complete structural assignment, synthesis, and antimicrobial profile of tridecaptin B1 is reported, as well as the putative gene cluster responsible for its biosynthesis. This peptide displays strong activity against multidrug resistant Gram-negative bacteria, a finding that is timely to the current problem of antibiotic resistance.

  13. Capnocytophaga canimorsus Sepsis Following a Minor Dog Bite to the Finger: Case Report.

    Science.gov (United States)

    Dedy, Nicolas J; Coghill, Sarah; Chandrashekar, Nanda Kumar S; Bindra, Randy R

    2016-01-01

    Capnocytophaga canimorsus is a gram-negative bacillus present in the oral cavities of 22% to 74% of healthy dogs. Capnocytophaga canimorsus has unique virulence factors that enable it to evade the human immune system and cause life-threatening sepsis following a dog bite. We report a previously well 68-year-old woman who presented with septic shock and multiorgan failure following a seemingly minor dog bite to the finger. The patient required intensive care treatment, intravenous antibiotic therapy, and multiple surgical procedures including amputation of the affected finger. The septicemia and coagulopathy that ensued resulted in gangrene and amputation of additional fingers and toes. The purpose of this report is to raise awareness of this organism among hand surgeons when faced with a patient presenting in septic shock and minimal signs at the site of a dog bite. Copyright © 2016 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  14. Characterization of the Extended-Spectrum beta-Lactamase Producers among Non-Fermenting Gram-Negative Bacteria Isolated from Burnt Patients

    Directory of Open Access Journals (Sweden)

    Mojdeh Hakemi Vala

    2013-09-01

    Full Text Available Please cite this article as: Hakemi Vala M, Hallajzadeh M, Fallah F, Hashemi A, Goudarzi H. Characterization of the extended-spectrum beta-lactamase producers among non-fermenting gram-negative bacteria isolated from burnt patients. Arch Hyg Sci 2013;2(1:1-6. Background & Aims of the Study: Extended-spectrum beta-Lactamases (ESBLs represent a major group of beta-lactamases which are responsible for resistance to oxyimino-cephalosporins and aztreonam and currently being identified in large numbers throughout the world. The objective of this study was to characterize ESBL producers among non-fermenter gram-negative bacteria isolated from burnt patients. Materials & Methods: During April to July 2012, 75 non-fermenter gram-negative bacilli were isolated from 240 bacterial cultures collected from wounds of burnt patients admitted to the Burn Unit at Shahid Motahari Hospital (Tehran, Iran. Bacterial isolation and identification was done using standard methods. Antimicrobial susceptibility testing was performed by disk diffusion method for all strains against selected antibiotics and minimum inhibitory concentration was determined by microdilution test. The ability to produce ESBL was detected through double disk synergy test among candidate strains. Results: Of 75 non-fermenter isolates, 47 Pseudomonas aeruginosa and 28 Acinetobacter baumannii were identified. The resistance of P. aeruginosa isolates to tested antibiotics in antibiogram test were 100% to cefpodoxime, 82.98% to ceftriaxone, 78.73% to imipenem, 75% to meropenem, 72.72% to gentamicin, 69.23% to ciprofloxacin and aztreonam, 67.57% to cefepime, 65.95% to ceftazidime, and 61.53% to piperacillin. The results for Acinetobacter baumannii were 100% to ceftazidime, cefepime, ciprofloxacin, imipenem, meropenem, cefpodoxime, and cefotaxim, 96.85% to gentamicin, 89.65% to ceftriaxone, 65.51% to aztreonam, and 40% to piperacillin. Double disk synergy test showed that 21 (28% of non

  15. [i]Legionella spp[/i]., amoebae and not-fermenting Gram negative bacteria in an Italian university hospital water system

    Directory of Open Access Journals (Sweden)

    Pasqualina Laganà

    2014-09-01

    Full Text Available [b]Introduction. [/b]In hospital and other health care facilities, contamination of water systems by potentially infectious microorganisms, such as bacteria, viruses and protozoa, is a source of nosocomial infections, which may originate fromcolonization of water pipes, cooling towers, spa pools, taps, showers and water supplies. [b]Objective. [/b]The study focuses on the occurrence of [i]Legionella spp.[/i], free-living amoebae and non-fermenting Gram-negative microorganisms in a University hospital water system located in the town of Messina (Sicily, Italy, which had never been examined previously. Materials and Methods. From January 2008 – March 2009, hot tap water samples were collected from 10 wards.[i] Legionella spp[/i]. recovered on selective culture medium were identified by microagglutination latex test; free-living amoebae were cultured using [i]Escherichia coli [/i]as a food source. Non-fermenting Gram negative microorganisms were identified by API 20 NE strips. [b]Results.[/b] [i]Legionella spp.[/i] were found in 33.33% of the samples. [i]L. pneumophila[/i] serogroup 1 was recovered from the Laboratory Diagnostic and Anaesthesia-Neurology Wards, with a peak of 3.5 × 10[sup]4[/sup] cfu/L in May 2008. [i]L. pneumophila[/i] serogroups 2–14 were found in the Othorhinolaryngology, Pathologic Anatomy, Paediatrics and Surgery Wards, and peaked (4 × 10[sup]4[/sup] cfu/L in April 2008. Pseudomonadaceae and Hyphomycetes were also detected. Legionella spp. were recovered from samples positive for non-pathogenic amoebae [i]Hartmannella spp[/i]. [b]Conclusion.[/b] This first study of a Messina hospital water system suggested potential health risks related to the detection of [i]Hartmannella spp[/i]., as reservoirs for[i] Legionella spp.[/i], and Pseudomonas aeruginosa, a Gram negative non-fermenting bacterium frequently causing nosocomial pneumonia. The urgent need for monitoring programmes and prevention measures to ensure hospital water

  16. Survey of innate immune responses to Burkholderia pseudomallei in human blood identifies a central role for lipopolysaccharide.

    Directory of Open Access Journals (Sweden)

    Narisara Chantratita

    Full Text Available B. pseudomallei is a gram-negative bacterium that causes the tropical infection melioidosis. In northeast Thailand, mortality from melioidosis approaches 40%. As exemplified by the lipopolysaccharide-Toll-like receptor 4 interaction, innate immune responses to invading bacteria are precipitated by activation of host pathogen recognition receptors by pathogen associated molecular patterns. Human melioidosis is characterized by up-regulation of pathogen recognition receptors and pro-inflammatory cytokine release. In contrast to many gram-negative pathogens, however, the lipopolysaccharide of B. pseudomallei is considered only weakly inflammatory. We conducted a study in 300 healthy Thai subjects to investigate the ex vivo human blood response to various bacterial pathogen associated molecular patterns, including lipopolysaccharide from several bacteria, and to two heat-killed B. pseudomallei isolates. We measured cytokine levels after stimulation of fresh whole blood with a panel of stimuli. We found that age, sex, and white blood cell count modulate the innate immune response to B. pseudomallei. We further observed that, in comparison to other stimuli, the innate immune response to B. pseudomallei is most highly correlated with the response to lipopolysaccharide. The magnitude of cytokine responses induced by B. pseudomallei lipopolysaccharide was significantly greater than those induced by lipopolysaccharide from Escherichia coli and comparable to many responses induced by lipopolysaccharide from Salmonella minnesota despite lower amounts of lipid A in the B. pseudomallei lipopolysaccharide preparation. In human monocytes stimulated with B. pseudomallei, addition of polymyxin B or a TLR4/MD-2 neutralizing antibody inhibited the majority of TNF-α production. Challenging existing views, our data indicate that the innate immune response to B. pseudomallei in human blood is largely driven by lipopolysaccharide, and that the response to B

  17. Quorum sensing signal molecules (acylated homoserine lactones) in Gram-negative fish pathogenic bacteria

    DEFF Research Database (Denmark)

    Bruhn, Jesper Bartholin; Dalsgaard, Inger; Nielsen, K.F.

    2005-01-01

    The aim of the present study was to investigate the production of quorum sensing signals (specifically acylated homoserine lactones, AHLs) among a selection of strains of Gram-negative fish bacterial pathogens. These signals are involved in the regulation of virulence factors in some human...... salmonicida and Vibrio splendidus were also positive. Aeromonas species produced N-butanoyl homoserine lactone (BHL) and N-hexanoyl homoserine lactone (HHL) and 1 additional product, whereas N-3-oxo-hexanoyl homoserine lactone (OHHL) and HHL were detected in Vibrio salmonicida. N-3-oxo-octanoyl homoserine...... lactone (OOHL) and N-3-octanoyl homoserine lactone (OHL) were detected in Y. ruckeii. AHLs were not detected from strains of Photobacterium damselae, Flavobacterium psychrophilum or Moritella viscosa. AHLs were extracted from fish infected with Y. ruckeri but not from fish infected with A. salmonicida...

  18. Sorption of lead onto two gram-negative marine bacteria in seawater

    Science.gov (United States)

    Harvey, Ronald W.; Leckie, James O.

    1985-01-01

    Laboratory adsorption experiments performed at environmentally significant lead (Pb) and cell concentrations indicate that the marine bacteria examined have significant binding capacities for Pb. However, the behavior governing Pb sorption onto gram-negative bacteria in seawater may be quite complex. The sorption kinetics appear to involve two distinct phases, i.e., a rapid removal of Pb from solution within the first few minutes, followed by a slow but nearly constant removal over many hours. Also, the average binding coefficient, calculated for Pb sorption onto bacteria and a measure of binding intensity, increases with decreasing sorption density (amounts of bacteria-associated Pb per unit bacterial surface) at low cell concentrations (105 cells ml−1), but decreases with decreasing sorption density at higher cell concentrations (107 cells ml−1). The latter effect is apparently due to the production of significant amounts of extra-cellular organics at high cell concentrations that compete directly with bacterial surfaces for available lead. Lead toxicity and active uptake by marine bacteria did not appear significant at the Pb concentrations used.

  19. A possible alternative to the error prone modified Hodge test to correctly identify the carbapenemase producing Gram-negative bacteria

    Directory of Open Access Journals (Sweden)

    S S Jeremiah

    2014-01-01

    Full Text Available Context: The modified Hodge test (MHT is widely used as a screening test for the detection of carbapenemases in Gram-negative bacteria. This test has several pitfalls in terms of validity and interpretation. Also the test has a very low sensitivity in detecting the New Delhi metallo-β-lactamase (NDM. Considering the degree of dissemination of the NDM and the growing pandemic of carbapenem resistance, a more accurate alternative test is needed at the earliest. Aims: The study intends to compare the performance of the MHT with the commercially available Neo-Sensitabs - Carbapenemases/Metallo-β-Lactamase (MBL Confirmative Identification pack to find out whether the latter could be an efficient alternative to the former. Settings and Design: A total of 105 isolates of Klebsiella pneumoniae resistant to imipenem and meropenem, collected prospectively over a period of 2 years were included in the study. Subjects and Methods: The study isolates were tested with the MHT, the Neo-Sensitabs - Carbapenemases/MBL Confirmative Identification pack and polymerase chain reaction (PCR for detecting the blaNDM-1 gene. Results: Among the 105 isolates, the MHT identified 100 isolates as carbapenemase producers. In the five isolates negative for the MHT, four were found to produce MBLs by the Neo-Sensitabs. The Neo-Sensitabs did not have any false negatives when compared against the PCR. Conclusions: The MHT can give false negative results, which lead to failure in detecting the carbapenemase producers. Also considering the other pitfalls of the MHT, the Neo-Sensitabs - Carbapenemases/MBL Confirmative Identification pack could be a more efficient alternative for detection of carbapenemase production in Gram-negative bacteria.

  20. Transferable integrons of Gram-negative bacteria isolated from the gut of a wild boar in the buffer zone of a national park.

    Science.gov (United States)

    Mokracka, Joanna; Koczura, Ryszard; Kaznowski, Adam

    2012-06-01

    The aim of this study was to determine the presence of integron-bearing Gram-negative bacteria in the gut of a wild boar (Sus scrofa L.) shot in the buffer zone of a national park. Five Gram-negative strains of Escherichia coli, Serratia odorifera, Hafnia alvei and Pseudomonas sp. were isolated. Four of these strains had class 2 integrase (intI2), and one harbored class 1 integrase (intI1). The integron-positive strains were multiresistant, i.e., resistant to at least three unrelated antibiotics. All of the integrons were transferred to E. coli J-53 (Rif(R)) in a conjugation assay. The results showed that a number of multiresistant, integron-containing bacterial strains of different genera may inhabit a single individual of a wild animal, allowing the possibility of transfer of antimicrobial resistance genes.

  1. Should gram stains have a role in diagnosing hip arthroplasty infections?

    Science.gov (United States)

    Johnson, Aaron J; Zywiel, Michael G; Stroh, D Alex; Marker, David R; Mont, Michael A

    2010-09-01

    The utility of Gram stains in diagnosing periprosthetic infections following total hip arthroplasty has recently been questioned. Several studies report low sensitivity of the test, and its poor ability to either confirm or rule out infection in patients undergoing revision total hip arthroplasty. Despite this, many institutions including that of the senior author continue to perform Gram stains during revision total hip arthroplasty. We assessed the sensitivity, specificity, accuracy, and positive and negative predictive values of Gram stains from surgical-site samplings taken from procedures on patients with both infected and aseptic revision total hip arthroplasties. A review was performed on patients who underwent revision total hip arthroplasty between 2000 and 2007. Eighty-two Gram stains were performed on patients who had infected total hip arthroplasties and underwent revision procedures. Additionally, of the 410 revision total hip arthroplasties performed on patients who were confirmed infection-free, 120 Gram stains were performed. Patients were diagnosed as infected using multiple criteria at the time of surgery. Sensitivity, specificity, positive and negative predictive values, and accuracy were calculated from these Gram stain results. The Gram stain demonstrated a sensitivity and specificity of 9.8% and 100%, respectively. In this series, the Gram stain had a negative predictive value of 62%, a positive predictive value of 100%, and an accuracy of 63%. Gram stains obtained from surgical-site samples had poor sensitivity and poor negative predictive value. Based on these findings, as well as those of other authors, we believe that Gram stains should no longer be considered for diagnosing infections in revision total hip arthroplasty. Level III, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.

  2. Synergistic effect of Carum copticum and Mentha piperita essential oils with ciprofloxacin, vancomycin, and gentamicin on Gram-negative and Gram-positive bacteria

    Science.gov (United States)

    Talei, Gholam-Reza; Mohammadi, Mohsen; Bahmani, Mahmoud; Kopaei, Mahmoud Rafieian

    2017-01-01

    Background: Infectious diseases have always been an important health issue in human communities. In the recent years, much research has been conducted on antimicrobial effects of nature-based compounds because of increased prevalence of antibiotic resistance. The present study was conducted to investigate synergistic effect of Carum copticum and Mentha piperita essential oils with ciprofloxacin, vancomycin, and gentamicin on Gram-negative and Gram-positive bacteria. Materials and Methods: In this experimental study, the synergistic effects of C. copticum and M. piperita essential oils with antibiotics on Staphylococcus aureus (ATCC 25923), Enterococcus faecalis (ATCC 29212), Escherichia coli (ATCC 8739), Pseudomonas aeruginosa (ATCC 9027), Staphylococcus epidermidis (ATCC 14990), and Listeria monocytogenes (ATCC 7644) were studied according to broth microdilution and the MIC and fractional inhibitory concentration (FIC) of these two essential oils determined. Results: C. copticum essential oil at 30 μg/ml could inhibit S. aureus, and in combination with vancomycin, decreased MIC from 0.5 to 0.12 μg/ml. Moreover, the FIC was derived 0.24 μg/ml which represents a potent synergistic effect with vancomycin against S. aureus growth. C. copticum essential oil alone or combined with other antibiotics is effective in treating bacterial infections. Conclusions: In addition, C. copticum essential oil can strengthen the activities of certain antibiotics, which makes it possible to use this essential oil, especially in drug resistance or to lower dosage or toxicity of the drugs. PMID:28929050

  3. Defining Multidrug Resistance of Gram-Negative Bacteria in the Dutch–German Border Region—Impact of National Guidelines

    Directory of Open Access Journals (Sweden)

    Robin Köck

    2018-01-01

    Full Text Available Preventing the spread of multidrug-resistant Gram-negative bacteria (MDRGNB is a public health priority. However, the definition of MDRGNB applied for planning infection prevention measures such as barrier precautions differs depending on national guidelines. This is particularly relevant in the Dutch–German border region, where patients are transferred between healthcare facilities located in the two different countries, because clinicians and infection control personnel must understand antibiograms indicating MDRGNB from both sides of the border and using both national guidelines. This retrospective study aimed to compare antibiograms of Gram-negative bacteria and classify them using the Dutch and German national standards for MDRGNB definition. A total of 31,787 antibiograms from six Dutch and four German hospitals were classified. Overall, 73.7% were no MDRGNB according to both guidelines. According to the Dutch and German guideline, 7772/31,787 (24.5% and 4586/31,787 (12.9% were MDRGNB, respectively (p < 0.0001. Major divergent classifications were observed for extended-spectrum β-lactamase (ESBL -producing Enterobacteriaceae, non-carbapenemase-producing carbapenem-resistant Enterobacteriaceae, Pseudomonas aeruginosa and Stenotrophomonas maltophilia. The observed differences show that medical staff must carefully check previous diagnostic findings when patients are transferred across the Dutch–German border, as it cannot be assumed that MDRGNB requiring special hygiene precautions are marked in the transferred antibiograms in accordance with both national guidelines.

  4. Interventional strategies and current clinical experience with carbapenemase-producing Gram-negative bacteria.

    Science.gov (United States)

    Akova, M; Daikos, G L; Tzouvelekis, L; Carmeli, Y

    2012-05-01

    The wide dissemination of carbapenemase-producing Gram-negatives (CPGNs), including enterobacterial species and non-fermenters, has caused a public health crisis of global dimensions. These organisms cause serious infections in hospitalized patients, and are associated with increased mortality. Cross-transmission is common, and outbreaks may occur in healthcare facilities where the infection control practices are inadequate. CPGNs exhibit extensive drug-resistant phenotypes, complicate therapy, and limit treatment options. Systematic data on therapy are limited. However, regimens combining two or more active agents seem to be more efficacious than monotherapy in carbapenemase-producing Klebsiella pneumoniae infections. Strict infection control measures, including active surveillance for timely detection of colonized patients, separation of carriers from non-carriers, and contact precautions, are of utmost importance, and may be the only effective way of preventing the introduction and transmission of these bacteria in healthcare settings. © 2012 The Authors. Clinical Microbiology and Infection © 2012 European Society of Clinical Microbiology and Infectious Diseases.

  5. Fermentative Degradation of Polyethylene Glycol by a Strictly Anaerobic, Gram-Negative, Nonsporeforming Bacterium, Pelobacter venetianus sp. nov

    OpenAIRE

    1983-01-01

    The synthetic polyether polyethylene glycol (PEG) with a molecular weight of 20,000 was anaerobically degraded in enrichment cultures inoculated with mud of limnic and marine origins. Three strains (Gra PEG 1, Gra PEG 2, and Ko PEG 2) of rod-shaped, gram-negative, nonsporeforming, strictly anaerobic bacteria were isolated in mineral medium with PEG as the sole source of carbon and energy. All strains degraded dimers, oligomers, and polymers of PEG up to a molecular weight of 20,000 completely...

  6. Novel pharmacotherapy for the treatment of hospital-acquired and ventilator-associated pneumonia caused by resistant gram-negative bacteria.

    Science.gov (United States)

    Kidd, James M; Kuti, Joseph L; Nicolau, David P

    2018-03-01

    Hospital-acquired and ventilator-associated bacterial pneumonia (HABP/VABP) are among the most prevalent infections in hospitalized patients, particularly those in the intensive care unit. Importantly, the frequency of multidrug resistant (MDR) Gram-negative (GN) bacteria as the bacteriologic cause of HABP/VABP is increasing. These include MDR Pseudomonas aeruginosa, Acinetobacter baumannii, and carbapenem resistant Enterobacteriaceae (CRE). Few antibiotics are currently available when such MDR Gram-negatives are encountered and older agents such as polymyxin B, colistin (polymyxin E), and tigecycline have typically performed poorly in HABP/VABP. Areas covered: In this review, the authors summarize novel antibiotics which have reached phase 3 clinical trials including patients with HABP/VABP. For each agent, the spectrum of activity, pertinent pharmacological characteristics, clinical trial data, and potential utility in the treatment of MDR-GN HABP/VABP is discussed. Expert opinion: Novel antibiotics currently available, and those soon to be, will expand opportunities to treat HABP/VABP caused by MDR-GN organisms and minimize the use of more toxic, less effective drugs. However, with sparse clinical data available, defining the appropriate role for each of the new agents is challenging. In order to maximize the utility of these antibiotics, combination therapy and the role of therapeutic drug monitoring should be investigated.

  7. Evaluation of pyrrolidonyl arylamidase for the identification of nonfermenting Gram-negative rods.

    Science.gov (United States)

    Bombicino, Karina A; Almuzara, Marisa N; Famiglietti, Angela M R; Vay, Carlos

    2007-01-01

    To evaluate the activity of pyrrolidonyl arylamidase (PYR) for the differentiation and identification of nonfermenting gram negative rods (NFGNR), 293 isolates were tested. A 24 h culture of each test organism was prepared. From this a 108-109 cfu/mL suspension was added to 0.25 mL of sterile physiologic solution. A PYR disk was then added and the test was incubated for 30 minutes at 35-37 degrees C, at environmental atmosphere. Reading was done by adding 1 drop of cinnamaldehyde reagent. Strains of Acinetobacter baumannii, Acinetobacter haemolyticus, Alcaligenes faecalis, Bergeyella zoohelcum, Bordetella bronchiseptica, Bordetella hinzii, Brevundimonas diminuta, Brevundimonas vesicularis, Brucella ovis, Brucella spp., Brucella suis, Burkholderia cepacia complex, Moraxella catarrhalis, Moraxella lacunata, Moraxella nonliquefaciens, Moraxella osloensis, Oligella ureolytica, Pseudomonas alcaligenes, Pseudomonas mendocina, Pseudomonas pseudoalcaligenes, Pseudomonas putida, Pseudomonas stutzeri, Pseudomonas Vb3, Psychrobacter phenylpyruvicus, and Stenotrophomonas maltophilia were PYR negative. On the other hand Achromobacter piechaudii, Achromobacter denitrificans, Achromobacter xylosoxidans, Burkholderia gladioli, Chryseobacterium gleum-indologenes, Comamonas testosroni, Cupriavidus pauculus, Delftia acidovorans, Elizabethkingia meningoseptica, Myroides spp., Ochrobactrum anthropi, Pseudomonas oryzihabitans, Ralstonia pickettii, Rhizobium radiobacter, Shewanella spp., Sphingobacterium multivorum, Sphingobacterium spiritivorum, and Weeksella virosa were PYR positive. Finally, Acinetobacter lwoffii, Pseudomonas aeruginosa, Pseudomonas fluorescens, Roseomonas spp., and Sphingomonas paucimobilis-parapaucimobilis were PYR variable. PYR testing should be considered as a useful tool to facilitate the identification of NFGNR.

  8. ESBL- and Carbapenemase-Producing Enterobacteriaceae in Patients with Bacteremia, Yangon, Myanmar, 2014.

    Science.gov (United States)

    Myat, Tin O; Hannaway, Rachel F; Zin, Khwar N; Htike, Wah W; Win, Kyu K; Crump, John A; Murdoch, David R; Ussher, James E

    2017-05-01

    Among 42 gram-negative bloodstream isolates from inpatients in 3 hospitals in Yangon, Myanmar, admitted during July-December 2014, 16 (38%) were extended-spectrum β-lactamase-producing Enterobacteriaceae and 6 (14%) produced carbapenemase. The high prevalence of multidrug-resistant gram-negative bacteria raises concerns about the empiric treatment of patients with sepsis in Yangon.

  9. Cell wall elongation mode in Gram-negative bacteria is determined by peptidoglycan architecture.

    Science.gov (United States)

    Turner, Robert D; Hurd, Alexander F; Cadby, Ashley; Hobbs, Jamie K; Foster, Simon J

    2013-01-01

    Cellular integrity and morphology of most bacteria is maintained by cell wall peptidoglycan, the target of antibiotics essential in modern healthcare. It consists of glycan strands, cross-linked by peptides, whose arrangement determines cell shape, prevents lysis due to turgor pressure and yet remains dynamic to allow insertion of new material, and hence growth. The cellular architecture and insertion pattern of peptidoglycan have remained elusive. Here we determine the peptidoglycan architecture and dynamics during growth in rod-shaped Gram-negative bacteria. Peptidoglycan is made up of circumferentially oriented bands of material interspersed with a more porous network. Super-resolution fluorescence microscopy reveals an unexpected discontinuous, patchy synthesis pattern. We present a consolidated model of growth via architecture-regulated insertion, where we propose only the more porous regions of the peptidoglycan network that are permissive for synthesis.

  10. Evaluation of Efficacy of the Current Disinfectants on Gram-negative Bacteria Isolated from Hospital in Yazd in 2014

    OpenAIRE

    Tahereh Jasemizad; Mehdi Mokhtari; Hengameh Zandi; Taher Shahriari; Fatemeh Sahlabadi; Akram Montazeri; Arefeh Dehghani Tafti

    2016-01-01

    as Pseudomonas, Acinetobacter, and Staphylococcus that appropriate disinfection can reduce these pathogens. The aim of this study was to evaluate the effect of different disinfectants on Gram-negative bacteria isolated from the surface of accidents and burn hospital in Yazd. Materials and Methods: In this study, 240 samples were randomly collected from different parts of accidents and burn hospital before and after disinfection. The samples were cultured on blood agar and Eusio...

  11. Epidemiology of meningitis with a negative CSF Gram stain: under-utilization of available diagnostic tests.

    Science.gov (United States)

    Nesher, L; Hadi, C M; Salazar, L; Wootton, S H; Garey, K W; Lasco, T; Luce, A M; Hasbun, R

    2016-01-01

    Meningitis with a negative cerebrospinal fluid Gram stain (CSF-GS) poses a diagnostic challenge as more than 50% of patients remain without an aetiology. The introduction of polymerase chain reaction (PCR) and arboviral serologies have increased diagnostic capabilities, yet large scale epidemiological studies evaluating their use in clinical practice are lacking. We conducted a prospective observational study in New Orleans between November 1999 and September 2008 (early era) when PCR was not widely available, and in Houston between November 2008 and June 2013 (modern era), when PCR was commonly used. Patients presenting with meningitis and negative CSF-GS were followed for 4 weeks. All investigations, PCR used, and results were recorded as they became available. In 323 patients enrolled, PCR provided the highest diagnostic yield (24·2%) but was ordered for 128 (39·6%) patients; followed by serology for arboviruses (15%) that was ordered for 100 (31%) of all patients. The yield of blood cultures was (10·3%) and that of CSF cultures was 4%; the yield for all other tests was meningitis and a negative CSF-GS, but both tests are being under-utilized.

  12. Serum inflammatory markers in the elderly: are they useful in differentiating sepsis from SIRS?

    Directory of Open Access Journals (Sweden)

    Mahshid Talebi-Taher

    2014-06-01

    Full Text Available Differentiating sepsis from other noninfectious causes of systemic inflammation is often difficult in the elderly. The aim of this study was to evaluate the ability of C-reactive protein (CRP, Erythrocyte Sedimentation Rate (ESR, procalcitonin (PCT, and Interleukin-6 (IL-6 to identify elderly patients with sepsis. In this single center prospective observational study, we included all consecutive elderly patients admitted with suspected sepsis and systemic inflammatory response syndrome (SIRS in an emergency department. Blood samples for measuring CRP, PCT, IL-6, ESR and white blood cells (WBC count were taken at first day of admission. Sensitivity, specificity, positive and negative predictive values were calculated for each inflammatory markers being studied. A total of 150 elderly patients aged 65 and older, 50 with sepsis and 50 with SIRS, and fifty individuals in a normal health status were included. CRP exhibited the greatest sensitivity (98% and negative predictive value (98.6% and performed best in differentiating patients with sepsis from those with SIRS. In a receiver operating characteristic curve analysis, IL-6 performed best in distinguishing between SIRS and the control group (AUC 0.75, 95% CI. On the other hand, both CRP and ESR appeared to be a more accurate diagnostic parameter for differentiating sepsis from SIRS among elderly patients.

  13. [Usefulness of sputum Gram staining in community-acquired pneumonia].

    Science.gov (United States)

    Sato, Tadashi; Aoshima, Masahiro; Ohmagari, Norio; Tada, Hiroshi; Chohnabayashi, Naohiko

    2002-07-01

    To evaluate the usefulness of sputum gram staining in community-acquired pneumonia (CAP), we reviewed 144 cases requiring hospitalization in the last 4 years. The sensitivity was 75.5%, specificity 68.2%, positive predictive value 74.1%, negative predictive value 69.8%, positive likelihood ratio 2.37, negative likelihood ratio 0.36 and accuracy 72.2% in 97 cases. Both sputum gram staining and culture were performed. Concerning bacterial pneumonia (65 cases), we compared the Gram staining group (n = 33), which received initial antibiotic treatment, based on sputum gram staining with the Empiric group (n = 32) that received antibiotics empirically. The success rates of the initial antibiotic treatment were 87.9% vs. 78.1% (P = 0.473); mean hospitalization periods were 9.67 vs. 11.75 days (P = 0.053); and periods of intravenous therapy were 6.73 vs. 7.91 days (P = 0.044), respectively. As for initial treatment, penicillins were used in the Gram staining group more frequently (P gram staining is useful for the shortening of the treatment period and the appropriate selection of initial antibiotics in bacterial pneumonia. We believe, therefore, that sputum gram staining is indispensable as a diagnostic tool CAP.

  14. Association between preterm labor and genitourinary tract infections caused by Trichomonas vaginalis, Mycoplasma hominis, Gram-negative bacilli, and coryneforms

    Directory of Open Access Journals (Sweden)

    Alaa El-Dien M.S. Hosny

    2017-09-01

    Conclusion: Our study demonstrated that the main risk factors for PTL were vaginal infection with T. vaginalis, M. hominis, coryneforms, and Gram-negative bacilli, and their determinants (vaginal pH>5, positive whiff test, heavy vaginal bleeding. Both young age (< 20 years and poor obstetric history were also the risk factors. Therefore, screening for genitourinary tract infections is strongly recommended to be included in prenatal care.

  15. Is the gram stain useful in the microbiologic diagnosis of VAP? A meta-analysis.

    Science.gov (United States)

    O'Horo, John C; Thompson, Deb; Safdar, Nasia

    2012-08-01

    In a meta-analysis examining respiratory specimen Gram stain for diagnosis of ventilator-associated pneumonia, absence of bacteria on Gram stain had a high negative predictive value, but a positive Gram stain correlated poorly with organisms recovered in culture. Rapid and accurate diagnosis of ventilator-associated pneumonia (VAP) is a major challenge and no generally accepted gold standard exists for VAP diagnosis. We conducted a meta-analysis to examine the role of respiratory specimen Gram stain to diagnose VAP, and the correlation with final culture results. In 21 studies, pooled sensitivity of Gram stain for VAP was 0.79 (95% confidence interval [CI], .77-0.81; P Gram stain for a VAP prevalence of 20%-30% was 91%, suggesting that VAP is unlikely with a negative Gram stain but the positive predictive value of Gram stain was only 40%. Pooled kappa was 0.42 for gram-positive organisms and 0.34 for gram-negative organisms, suggesting fair concordance between organisms on Gram stain and recovery by culture. Therefore, a positive Gram stain should not be used to narrow anti-infective therapy until culture results become available.

  16. Central-peripheral Temperature Monitoring as a Marker for Diagnosing Late-onset Neonatal Sepsis.

    Science.gov (United States)

    Leante-Castellanos, José Luis; Martínez-Gimeno, Antonio; Cidrás-Pidré, Manuel; Martínez-Munar, Gerardo; García-González, Ana; Fuentes-Gutiérrez, Carmen

    2017-12-01

    The prognosis for late-onset sepsis depends largely on a timely diagnosis. We assess central-peripheral temperature difference monitoring as a marker for late-onset neonatal sepsis diagnosis. We performed a prospective, observational study focusing on a cohort of 129 very low-birth-weight infants. Thermal gradient alteration was defined as a difference of > 2°C maintained during 4 hours. We then determined its association with the late-onset sepsis variable through logistic regression. We enrolled 129 preterm babies in 52 months. Thermal gradient alterations showed an adjusted odds ratio for late-onset sepsis of 23.60 (95% confidence interval [CI], 6.80-81.88), with a sensitivity of 83% and negative predictive value of 94%. In 71% of cases, thermal gradient alteration was the first clinical sign of sepsis, while C-reactive protein was peripheral temperature differences are an early sign of evolving late-onset sepsis.

  17. In vitro activity of potential old and new drugs against multidrug-resistant gram-negatives.

    Science.gov (United States)

    Rizek, Camila; Ferraz, Juliana Rosa; van der Heijden, Inneke Marie; Giudice, Mauro; Mostachio, Anna Karina; Paez, Jorge; Carrilho, Claudia; Levin, Anna Sara; Costa, Silvia F

    2015-02-01

    The aim of this study was to evaluate the in vitro susceptibility of MDR gram-negatives bacteria to old drugs such as polymyxin B, minocycline and fosfomycin and new drugs such as tigecycline. One hundred and fifty-three isolates from 4 Brazilian hospitals were evaluated. Forty-seven Acinetobacter baumannii resistant to carbapenens harboring adeB, blaOxA23, blaOxA51, blaOxA143 and blaIMP genes, 48 Stenotrophomonas maltophilia including isolates resistant to levofloxacin and/or trimethoprim-sulfamethoxazole harboring sul-1, sul-2 and qnrMR and 8 Serratia marcescens and 50 Klebsiella pneumoniae resistant to carbapenens harboring blaKPC-2 were tested to determine their minimum inhibitory concentrations (MICs) by microdilution to the following drugs: minocycline, ampicillin-sulbactam, tigecycline, and polymyxin B and by agar dilution to fosfomycin according with breakpoint criteria of CLSI and EUCAST (fosfomycin). In addition, EUCAST fosfomycin breakpoint for Pseudomonas spp. was applied for Acinetobacter spp and S. maltophilia, the FDA criteria for tigecycline was used for Acinetobacter spp and S. maltophilia and the Pseudomonas spp polymyxin B CLSI criterion was used for S. maltophilia. Tigecycline showed the best in vitro activity against the MDR gram-negative evaluated, followed by polymyxin B and fosfomycin. Polymyxin B resistance among K. pneumoniae was detected in 6 isolates, using the breakpoint of MIC > 8 ug/mL. Two of these isolates were resistant to tigecycline. Minocycline was tested only against S. maltophilia and A. baumannii and showed excellent activity against both. Fosfomycin seems to not be an option to treat infections due to the A. baumannii and S. maltophilia isolates according with EUCAST breakpoint, on the other hand, showed excellent activity against S. marcescens and K. pneumoniae. Copyright © 2014 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  18. Impact of CT in patients with sepsis of unknown origin

    International Nuclear Information System (INIS)

    Barkhausen, J.; Stoeblen, F.; Mueller, R.D.

    1999-01-01

    Purpose: To evaluate the diagnostic relevance of CT in patients with sepsis of unknown origin. Material and Methods: Sixty-three consecutive intensive care patients with suspicion of an abscess and negative or inconclusive previous radiological examinations were included. CT was performed using the helical technique. A total of 45 abdominal and 38 chest examinations were evaluated. Results: 5/38 examinations of the chest revealed the source of sepsis (pleural empyema 2, lung abscess 1, mediastinitis 1, retrosternal abscess 1). 7/45 abdominal CT examinations showed the source of sepsis (intraabdominal abscess 2, hepatic abscess 3, intestinal perforation 1, gangrenous colitis 1). Conclusion: CT is useful for the evaluation of patients with fever or sepsis without a known source. Due to the detection of a spetic focus by CT, 19% of the patients in our study could be immediately referred to causal therapy as percutaneous drainage or surgery. (orig.)

  19. Impact of CT in patients with sepsis of unknown origin

    Energy Technology Data Exchange (ETDEWEB)

    Barkhausen, J.; Stoeblen, F.; Mueller, R.D. [University Hospital Essen (Germany). Dept. of Radiology; Dominguez-Fernandez, E. [University Hospital Essen (Germany). Dept. of General Surgery; Henseke, P. [Nycomed-Amersham Arzneimittel GmbH, Muenchen (Germany)

    1999-09-01

    Purpose: To evaluate the diagnostic relevance of CT in patients with sepsis of unknown origin. Material and Methods: Sixty-three consecutive intensive care patients with suspicion of an abscess and negative or inconclusive previous radiological examinations were included. CT was performed using the helical technique. A total of 45 abdominal and 38 chest examinations were evaluated. Results: 5/38 examinations of the chest revealed the source of sepsis (pleural empyema 2, lung abscess 1, mediastinitis 1, retrosternal abscess 1). 7/45 abdominal CT examinations showed the source of sepsis (intraabdominal abscess 2, hepatic abscess 3, intestinal perforation 1, gangrenous colitis 1). Conclusion: CT is useful for the evaluation of patients with fever or sepsis without a known source. Due to the detection of a spetic focus by CT, 19% of the patients in our study could be immediately referred to causal therapy as percutaneous drainage or surgery. (orig.)

  20. Lactic Acid Bacteria Inducing a Weak Interleukin-12 and Tumor Necrosis Alpha Response in Human Dendritic Cells Inhibit Strongly Stimulating Lactic Acid Bacteria but Act Synergistically with Gram-Negative Bacteria

    DEFF Research Database (Denmark)

    Zeuthen, Louise Hjerrild; Christensen, Hanne Risager; Frøkiær, Hanne

    2006-01-01

    The development and maintenance of immune homeostasis indispensably depend on signals from the gut flora. Lactic acid bacteria (LAB), which are gram-positive (G+) organisms, are plausible significant players and have received much attention. Gram-negative (G-) commensals, such as members...