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Sample records for bacteria modulates infections

  1. Helicobacter bilis Infection Alters Mucosal Bacteria and Modulates Colitis Development in Defined Microbiota Mice.

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    Atherly, Todd; Mosher, Curtis; Wang, Chong; Hostetter, Jesse; Proctor, Alexandra; Brand, Meghan W; Phillips, Gregory J; Wannemuehler, Michael; Jergens, Albert E

    2016-11-01

    Helicobacter bilis infection of C3H/HeN mice harboring the altered Schaedler flora (ASF) triggers progressive immune responsiveness and the development of colitis. We sought to investigate temporal alterations in community structure of a defined (ASF-colonized) microbiota in normal and inflamed murine intestines and to correlate microbiota changes to histopathologic lesions. The colonic mucosal microbiota of healthy mice and ASF mice colonized with H. bilis for 3, 6, or 12 weeks were investigated by fluorescence in situ hybridization targeting the 16S ribosomal RNA genes of total bacteria, group-specific organisms, and individual ASF bacterial species. Microbial profiling of ASF and H. bilis abundance was performed on cecal contents. Helicobacter bilis-colonized mice developed colitis associated with temporal changes in composition and spatial distribution of the mucosal microbiota. The number of total bacteria, ASF519, and helicobacter-positive bacteria were increased (P attachment, or by invasion, and this interaction is differentially expressed over time.

  2. Chronic oral infection with major periodontal bacteria Tannerella forsythia modulates systemic atherosclerosis risk factors and inflammatory markers.

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    Chukkapalli, Sasanka S; Rivera-Kweh, Mercedes F; Velsko, Irina M; Chen, Hao; Zheng, Donghang; Bhattacharyya, Indraneel; Gangula, Pandu R; Lucas, Alexandra R; Kesavalu, Lakshmyya

    2015-04-01

    Tannerella forsythia is a Gram-negative anaerobic organism that inhabits the subgingival cavity and initiates connective tissue destruction and alveolar bone resorption in periodontal disease (PD). PD is a chronic immunoinflammatory disease and has been linked to several systemic diseases including atherosclerosis. This study evaluated the effects of a chronic oral infection with T. forsythia ATCC 43037 on the induction of PD, inflammatory markers and atherosclerosis risk factors in hyperlipidemic ApoE(null) mice. Mice were orally infected for 12 and 24 weeks prior to euthanasia. Bacterial colonization of the oral cavity and bacteremia was confirmed via isolation of genomic DNA from oral plaque and tissues. Oral infection elicited significantly elevated levels of serum IgG and IgM antibodies and alveolar bone resorption compared to control mice. Tannerella forsythia-infected mice had increased serum amyloid A, and significantly reduced serum nitric oxide when compared to controls. Tannerella forsythia chronic infection also significantly increased serum lipoproteins suggesting altered cholesterol metabolism and potential for aortic inflammation. Despite enhanced acute phase reactants and altered lipid profiles, T. forsythia infection was associated with decreased aortic plaque. This study investigates the potential of a known periodontal bacterial pathogen found in atherosclerotic plaque in humans to accelerate atherosclerosis in hyperlipdemic mice. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  3. Bacteria Isolated from Post-Partum Infections

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    Nahid Arianpour

    2009-06-01

    Full Text Available Objective: This study was undertaken with an aim to determine bacterial species involved in post partum infections and also their abundance in patients admitted to at Khanevadeh hospital. In this study out of three different kinds of postpartum infections (i.e. genital, breast and urinary tract, only genital infection is considered.Materials and Methods: Post partum infection among 6077 patients (inpatients and re-admitted patients of Khanevadeh hospital from 2003 till 2008 was studied in this descriptive study. Samples were collected from patients for laboratory diagnosis to find out the causative organisms.Results: Follow up of mothers after delivery revealed 7.59% (461 patients had post partum infection, out of which 1.03% (63 patients were re-hospitalized. Infection was more often among younger mothers. Bacteria isolated and identified were both aerobic and anaerobic cocci and bacilli, majority of which were normal flora of the site of infection. Though, some pathogenic bacteria like Staphylococcus aureus, Neisseria gonorrhea, Chlamydia trachomatis,were also the causative agents. The commonest infection was infection at the site of episiotomy. Conclusion: Puerperal infection was detected in of 7.59% mothers. Bacteria isolated were both aerobic and anaerobic cocci and bacilli, majority of which were normal flora. However; some pathogenic bacteria were isolated.

  4. Modulation of immune homeostasis by commensal bacteria

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    Ivanov, Ivaylo I.; Littman, Dan R.

    2011-01-01

    Intestinal bacteria form a resident community that has co-evolved with the mammalian host. In addition to playing important roles in digestion and harvesting energy, commensal bacteria are crucial for the proper functioning of mucosal immune defenses. Most of these functions have been attributed to the presence of large numbers of “innocuous” resident bacteria that dilute or occupy niches for intestinal pathogens or induce innate immune responses that sequester bacteria in the lumen, thus quenching excessive activation of the mucosal immune system. However it has recently become obvious that commensal bacteria are not simply beneficial bystanders, but are important modulators of intestinal immune homeostasis and that the composition of the microbiota is a major factor in pre-determining the type and robustness of mucosal immune responses. Here we review specific examples of individual members of the microbiota that modify innate and adaptive immune responses, and we focus on potential mechanisms by which such species-specific signals are generated and transmitted to the host immune system. PMID:21215684

  5. Intravaginal lactic Acid bacteria modulated local and systemic immune responses and lowered the incidence of uterine infections in periparturient dairy cows.

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    Qilan Deng

    Full Text Available The objective of this investigation was to evaluate whether intravaginal infusion of a lactic acid bacteria (LAB cocktail around parturition could influence the immune response, incidence rate of uterine infections, and the overall health status of periparturient dairy cows. One hundred pregnant Holstein dairy cows were assigned to 1 of the 3 experimental groups as follows: 1 one dose of LAB on wk -2 and -1, and one dose of carrier (sterile skim milk on wk +1 relative to the expected day of parturition (TRT1; 2 one dose of LAB on wk -2, -1, and +1 (TRT2, and 3 one dose of carrier on wk -2, -1, and +1 (CTR. The LAB were a lyophilized culture mixture composed of Lactobacillus sakei FUA3089, Pediococcus acidilactici FUA3138, and Pediococcus acidilactici FUA3140 with a cell count of 108-109 cfu/dose. Blood samples and vaginal mucus were collected once a week from wk -2 to +3 and analyzed for content of serum total immunoglobulin G (IgG, lipopolysaccharide-binding protein (LBP, serum amyloid A (SAA, haptoglobin (Hp, tumor necrosis factor (TNF, interleukin (IL-1, IL-6, and vaginal mucus secretory IgA (sIgA. Clinical observations including rectal temperature, vaginal discharges, retained placenta, displaced abomasum, and laminitis were monitored from wk -2 to +8 relative to calving. Results showed that intravaginal LAB lowered the incidence of metritis and total uterine infections. Intravaginal LAB also were associated with lower concentrations of systemic LBP, an overall tendency for lower SAA, and greater vaginal mucus sIgA. No differences were observed for serum concentrations of Hp, TNF, IL-1, IL-6 and total IgG among the treatment groups. Administration with LAB had no effect on the incidence rates of other transition cow diseases. Overall intravaginal LAB lowered uterine infections and improved local and systemic immune responses in the treated transition dairy cows.

  6. Bacteria-Targeting Nanoparticles for Managing Infections

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    Radovic-Moreno, Aleksandar Filip

    Bacterial infections continue to be a significant concern particularly in healthcare settings and in the developing world. Current challenges include the increasing spread of drug resistant (DR) organisms, the side effects of antibiotic therapy, the negative consequences of clearing the commensal bacterial flora, and difficulties in developing prophylactic vaccines. This thesis was an investigation of the potential of a class of polymeric nanoparticles (NP) to contribute to the management of bacterial infections. More specifically, steps were taken towards using these NPs (1) to achieve greater spatiotemporal control over drug therapy by more targeted antibiotic delivery to bacteria, and (2) to develop a prophylactic vaccine formulation against the common bacterial sexually transmitted disease (STD) caused by Chlamydia trachomatis. In the first part, we synthesized polymeric NPs containing poly(lactic-co-glycolic acid)-block-poly(L-histidine)-block-poly(ethylene glycol) (PLGA-PLH-PEG). We show that these NPs are able to bind to bacteria under model acidic infection conditions and are able to encapsulate and deliver vancomycin to inhibit the growth of Staphylococcus aureus bacteria in vitro. Further work showed that the PLGA-PLH-PEG-based NPs demonstrated the potential for competition for binding bacteria at a site of infection from soluble protein and model phagocytic and tissue-resident cells in a NP composition dependent manner. The NPs demonstrated low toxicity in vitro, were well tolerated by mice in vivo, and circulated in the blood on timescales comparable to control PLGA-PEG NPs. In the second part, we used PLGA-PLH-PEG-based NPs to design a prophylactic vaccine against the obligate intracellular bacterium Chlamydia trachomatis, the most common cause of bacterial STD in the world. Currently, no vaccines against this pathogen are approved for use in humans. We first formulated NPs encapsulating the TLR7 agonist R848 conjugated to poly(lactic acid) (R848-PLA

  7. Vanillin selectively modulates the action of antibiotics against resistant bacteria.

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    Bezerra, Camila Fonseca; Camilo, Cicera Janaine; do Nascimento Silva, Maria Karollyna; de Freitas, Thiago Sampaio; Ribeiro-Filho, Jaime; Coutinho, Henrique Douglas Melo

    2017-12-01

    The treatment of infections caused by microorganisms that are resistant to antibiotics represent one of the main challenges of medicine today, especially due to the inefficacy of long-term drug therapy. In the search for new alternatives to treat these infections, many researchers have been looking for new substances derived from natural products to replace, or be used in combination with conventional antibiotics. Vanillin is a phenolic compound whose antimicrobial activity has been used in the elimination of pathogens present in fruits and vegetables. However, its antibacterial and modulating properties remain to be characterized. Therefore, this work aimed to evaluate the antibacterial activity and analyze the modulator activity of vanillin in association with conventional antibiotics. The antimicrobial activity of vanillin was evaluated using the microdilution method to determine the Minimum Inhibitory Concentration (MIC) Standard strains of Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and multi-resistant strains of Escherichia coli 06, Staphylococcus aureus 10, Pseudomonas aeruginosa 24 were used in this study. The antibiotic modulating effect was analyzed by combining vanillin with Norfloxacin, Imipenem, Gentamicin, Erythromycin and Tetracycline against the following multiresistant bacteria strains: Escherichia coli 06, Staphylococcus aureus 10 and Pseudomonas aeruginosa 24. Data were analyzed using the ANOVA test of two tracks followed by the post hoc Bonferroni test. Vanillin presented CIMs ≥1024μg/mL against all tested strains demonstrating that it did not present significant antibacterial activity. However, modulated the activity of gentamicin and imipenem against S. aureus and E. coli, causing a synergistic effect, but did not affect the activity of norfloxacin, tetracycline and erythromycin against these same microorganisms. A synergistic effect was also obtained from the association of vanillin with norfloxacin against P

  8. AZF Microdeletions in Human Semen Infected with Bacteria

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    Hayfa H Hassani

    2011-11-01

    Full Text Available Bacterial infections are associated with infertility in men. This study was aimed to investigate microdeletions on Yq chromosome in semen infected with bacteria by using bacteriological, biochemical, and serological assays. The investigation showed that 107 of 300 (84.80% semen samples collected from infertile men with primary or secondary infertility were infected with different species of bacteria. Chlamydia trachomatis and Neisseria gonorrheae were the most frequently diagnosed bacteria in the infected semen samples. The percentages of infections of semen samples with C. trachomatis and N. gonorrhea were 42.31% and 35.28% respectively. Genomic DNA from each semen sample infected with predominant bacteria was analyzed for AZF deletions by using multiplex PCR. Different patterns of AZF microdeletions were obtained. It can be concluded that sexually transmitted bacteria may contribute in microdeletions of Yq chromosome by indirectly producing reactive oxygen species and causing gene defect in AZF regions.

  9. [Application of anaerobic bacteria detection in oral and maxillofacial infection].

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    Bao, Zhen-ying; Lin, Qin; Meng, Yan-hong; He, Chun; Su, Jia-zeng; Peng, Xin

    2016-02-18

    To investigate the distribution and drug resistance of anaerobic bacteria in the patients with oral and maxillofacial infection. Aerobic and anaerobic bacteria cultures from 61 specimens of pus from the patients with oral and maxillofacial infection in the Department of Oral and Maxillofacial Surgery, Peking University School of Stomatology were identified. The culture type was evaluated by API 20A kit and drug resistance test was performed by Etest method. The clinical data and antibacterial agents for the treatment of the 61 cases were collected, and the final outcomes were recorded. The bacteria cultures were isolated from all the specimens, with aerobic bacteria only in 6 cases (9.8%), anaerobic bacteria only in 7 cases (11.5%), and both aerobic and anaerobic bacteria in 48 cases (78.7%). There were 55 infected cases (90.2%) with anaerobic bacteria, and 81 anaerobic bacteria stains were isolated. The highest bacteria isolation rate of Gram positive anaerobic bacteria could be found in Peptostreptococcus, Bifidobacterium and Pemphigus propionibacterium. No cefoxitin, amoxicillin/carat acid resistant strain was detected in the above three Gram positive anaerobic bacteria. The highest bacteria isolation rate of Gram negative anaerobic bacteria could be detected in Porphyromonas and Prevotella. No metronidazole, cefoxitin, amoxicillin/carat acid resistant strain was found in the two Gram negative anaerobic bacteria. In the study, 48 patients with oral and maxillofacial infection were treated according to the results of drug resistance testing, and the clinical cure rate was 81.3%. Mixed aerobic and anaerobic bacteria cultures are very common in most oral and maxillofacial infection patients. Anaerobic bacteria culture and drug resistance testing play an important role in clinical treatment.

  10. Seed-vectored endophytic bacteria modulate development of rice seedlings.

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    Verma, S K; Kingsley, K; Irizarry, I; Bergen, M; Kharwar, R N; White, J F

    2017-06-01

    The aim of the present study was to evaluate the effects of the removal of indigenous bacteria from rice seeds on seedling growth and development. Here we report the presence of three indigenous endophytic bacteria in rice seeds that play important roles in modulating seedling development (shoot and root lengths, and formation of root hairs and secondary roots) and defence against pathogens. Seed-associated bacteria were removed using surface sterilization with NaOCl (bleach) followed by antibiotic treatment. When bacteria were absent, growth of seedlings in terms of root hair development and overall seedling size was less than that of seedlings that contained bacteria. Reactive oxygen staining of seedlings showed that endophytic bacteria became intracellular in root parenchyma cells and root hairs. Roots containing endophytic bacteria were seen to stain densely for reactive oxygen, while roots free of bacteria stained lightly for reactive oxygen. Bacteria were isolated and identified as Enterobacter asburiae (VWB1), Pantoea dispersa (VWB2) and Pseudomonas putida (VWB3) by 16S rDNA sequencing. Bacteria were found to produce indole acetic acid (auxins), inhibited the pathogen Fusarium oxysporum and solubilized phosphate. Reinoculation of bacteria onto seedlings derived from surface-disinfected rice and Bermuda grass seeds significantly restored seedling growth and development. Rice seeds harbour indigenous bacterial endophytes that greatly influence seedling growth and development, including root and shoot lengths, root hair formation and disease susceptibility of rice seedlings. This study shows that seeds of rice naturally harbour bacterial endophytes that play key roles in modulation of seedling development. © 2017 The Society for Applied Microbiology.

  11. Commensal bacteria modulate the tumor microenvironment.

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    Poutahidis, Theofilos; Erdman, Susan E

    2016-09-28

    It has been recently shown that gut microbes modulate whole host immune and hormonal factors impacting the fate of distant preneoplastic lesions toward malignancy or regression. This raises the possibility that the tumor microenvironment interacts with broader systemic microbial-immune networks. These accumulated findings suggest novel therapeutic opportunities for holobiont engineering in emerging tumor microenvironments. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  12. Parasitic infection improves survival from septic peritonitis by enhancing mast cell responses to bacteria in mice.

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    Rachel E Sutherland

    Full Text Available Mammals are serially infected with a variety of microorganisms, including bacteria and parasites. Each infection reprograms the immune system's responses to re-exposure and potentially alters responses to first-time infection by different microorganisms. To examine whether infection with a metazoan parasite modulates host responses to subsequent bacterial infection, mice were infected with the hookworm-like intestinal nematode Nippostrongylus brasiliensis, followed in 2-4 weeks by peritoneal injection of the pathogenic bacterium Klebsiella pneumoniae. Survival from Klebsiella peritonitis two weeks after parasite infection was better in Nippostrongylus-infected animals than in unparasitized mice, with Nippostrongylus-infected mice having fewer peritoneal bacteria, more neutrophils, and higher levels of protective interleukin 6. The improved survival of Nippostrongylus-infected mice depends on IL-4 because the survival benefit is lost in mice lacking IL-4. Because mast cells protect mice from Klebsiella peritonitis, we examined responses in mast cell-deficient Kit(W-sh/Kit(W-sh mice, in which parasitosis failed to improve survival from Klebsiella peritonitis. However, adoptive transfer of cultured mast cells to Kit(W-sh/Kit(W-sh mice restored survival benefits of parasitosis. These results show that recent infection with Nippostrongylus brasiliensis protects mice from Klebsiella peritonitis by modulating mast cell contributions to host defense, and suggest more generally that parasitosis can yield survival advantages to a bacterially infected host.

  13. Activation of type III interferon genes by pathogenic bacteria in infected epithelial cells and mouse placenta.

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    Hélène Bierne

    Full Text Available Bacterial infections trigger the expression of type I and II interferon genes but little is known about their effect on type III interferon (IFN-λ genes, whose products play important roles in epithelial innate immunity against viruses. Here, we studied the expression of IFN-λ genes in cultured human epithelial cells infected with different pathogenic bacteria and in the mouse placenta infected with Listeria monocytogenes. We first showed that in intestinal LoVo cells, induction of IFN-λ genes by L. monocytogenes required bacterial entry and increased further during the bacterial intracellular phase of infection. Other Gram-positive bacteria, Staphylococcus aureus, Staphylococcus epidermidis and Enterococcus faecalis, also induced IFN-λ genes when internalized by LoVo cells. In contrast, Gram-negative bacteria Salmonella enterica serovar Typhimurium, Shigella flexneri and Chlamydia trachomatis did not substantially induce IFN-λ. We also found that IFN-λ genes were up-regulated in A549 lung epithelial cells infected with Mycobacterium tuberculosis and in HepG2 hepatocytes and BeWo trophoblastic cells infected with L. monocytogenes. In a humanized mouse line permissive to fetoplacental listeriosis, IFN-λ2/λ3 mRNA levels were enhanced in placentas infected with L. monocytogenes. In addition, the feto-placental tissue was responsive to IFN-λ2. Together, these results suggest that IFN-λ may be an important modulator of the immune response to Gram-positive intracellular bacteria in epithelial tissues.

  14. Current taxonomy of phages infecting lactic acid bacteria

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    Jennifer eMahony

    2014-01-01

    Full Text Available Phages infecting lactic acid bacteria have been the focus of significant research attention over the past three decades. Through the isolation and characterization of hundreds of phage isolates, it has been possible to classify phages of the dairy starter and adjunct bacteria Lactococus lactis, Streptococcus thermophilus, Leuconostoc spp. and Lactobacillus spp. Among these, phages of L. lactis have been most thoroughly scrutinized and serve as an excellent model system to address issues that arise when attempting taxonomic classification of phages infecting other LAB species. Here, we present an overview of the current taxonomy of phages infecting LAB genera of industrial significance, the methods employed in these taxonomic efforts and how these may be employed for the taxonomy of phages of currently underrepresented and emerging phage species.

  15. Modulation of host responses by oral commensal bacteria

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    Deirdre A. Devine

    2015-02-01

    Full Text Available Immunomodulatory commensal bacteria are proposed to be essential for maintaining healthy tissues, having multiple roles including priming immune responses to ensure rapid and efficient defences against pathogens. The default state of oral tissues, like the gut, is one of inflammation which may be balanced by regulatory mechanisms and the activities of anti-inflammatory resident bacteria that modulate Toll-like receptor (TLR signalling or NF-κB activation, or influence the development and activities of immune cells. However, the widespread ability of normal resident organisms to suppress inflammation could impose an unsustainable burden on the immune system and compromise responses to pathogens. Immunosuppressive resident bacteria have been isolated from the mouth and, for example, may constitute 30% of the resident streptococci in plaque or on the tongue. Their roles in oral health and dysbiosis remain to be determined. A wide range of bacterial components and/or products can mediate immunomodulatory activity, raising the possibility of development of alternative strategies for therapy and health promotion using probiotics, prebiotics, or commensal-derived immunomodulatory molecules.

  16. Natural Gastric Infection with Helicobacter pylori in Monkeys: A Model for Spiral Bacteria Infection in Humans

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    1994-01-01

    Methods: Infection and gastritis were have facilitated larger epidemiological studies. Another graded blindly by histological analysis and culture of...infec- with both types of bacteria by histological analysis and tion. Gastritis scores began to decrease 1 month after culture of H. pylori. In these 3...indicated that monkeys were not Infected. Gastritis score was :1.5 this organism belongs in the Helicobacter genus, and it in animals uninfected or

  17. Vaginosis-associated bacteria and its association with HPV infection.

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    Romero-Morelos, Pablo; Bandala, Cindy; Jiménez-Tenorio, Julián; Valdespino-Zavala, Mariana; Rodríguez-Esquivel, Miriam; Gama-Ríos, Reyna Anaid; Bandera, Artfy; Mendoza-Rodríguez, Mónica; Taniguchi, Keiko; Marrero-Rodríguez, Daniel; López-Romero, Ricardo; Ramón-Gallegos, Eva; Salcedo, Mauricio

    2018-03-12

    Cervical cancer is an important health problem in our country. It is known that there are several risk factors for this neoplasm, and it has been suggested that cervical microbiome alterations could play a role in the development and progress of cancer. Bacterial vaginosis associated bacteria such as Atopobium vaginae and Gardnerella vaginalis has been suggested as potential risk factor for cervical lesions and cervical cancer. DNA from 177 cervical scraping samples was studied: 104 belonged to women without cytological or colposcopic alterations and 73 samples from precursor lesions with previous human papillomavirus (HPV) infection history. All samples were screened for Atopobium vaginae, Gardnerella vaginalis and HPV by PCR. High HPV prevalence was found in precursor samples, and 30% of samples without lesions were positive for HPV. Virtually all samples contained sequences of both bacteria, and interestingly, there was not HPV association observed; these results could suggest that these microorganisms could be part of the cervical microbiome in Mexican population. The results obtained indicate that the bacteria analysed could be part of normal biome in Mexican women, suggesting a potential reconsideration of the pathogen role of these microorganisms. Copyright © 2018 Elsevier España, S.L.U. All rights reserved.

  18. Leukocyte and bacteria imaging in prosthetic joint infection

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    AWJM Glaudemans

    2013-01-01

    Full Text Available There has been a significant increase in the number of joint prosthesis replacements worldwide. Although relatively uncommon, complications can occur with the most serious being an infection. Various radiological and nuclear imaging techniques are available to diagnose prosthetic joint infections (PJI. In this review article, we describe the pathophysiology of PJI, the principles of nuclear medicine imaging and the differences between Single Photon Emission Computed Tomography (SPECT and Positron Emission Tomography (PET. The value of nuclear medicine techniques for clinical practice is also discussed.Then we provide an overview of the most often used radionuclide imaging techniques that may be helpful in diagnosing prosthetic joint infection: the 67Ga-citrate, labelled white blood cells in vitro and in vivo (monoclonal antibodies directed against specific targets on the leukocytes, and 18F-fluorodeoxyglucose (18F-FDG. We describe their working methods, the pitfalls, and the interpretation criteria. Furthermore, we review recent advances in imaging bacteria, a molecular imaging method that holds promises for the detection of occult infections. We conclude proposing two diagnostic flow-charts, based on data in the literature, that could help the clinicians to choose the best nuclear imaging method when they have a patient with suspicion of or with proven PJI.

  19. Temperature-Dependent Effects of Cutaneous Bacteria on a Frog’s Tolerance of Fungal Infection

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    Matthew J. Robak

    2018-03-01

    Full Text Available Defense against pathogens is one of many benefits that bacteria provide to animal hosts. A clearer understanding of how changes in the environment affect the interactions between animals and their microbial benefactors is needed in order to predict the impact and dynamics of emerging animal diseases. Due to its dramatic effects on the physiology of animals and their pathogens, temperature may be a key variable modulating the level of protection that beneficial bacteria provide to their animal hosts. Here we investigate how temperature and the makeup of the skin microbial community affect the susceptibility of amphibian hosts to infection by Batrachochytrium dendrobatidis (Bd, one of two fungal pathogens known to cause the disease chytridiomycosis. To do this, we manipulated the skin bacterial communities of susceptible hosts, northern cricket frogs (Acris crepitans, prior to exposing these animals to Bd under two different ecologically relevant temperatures. Our manipulations included one treatment where antibiotics were used to reduce the skin bacterial community, one where the bacterial community was augmented with the antifungal bacterium, Stenotrophomonas maltophilia, and one in which the frog’s skin bacterial community was left intact. We predicted that frogs with reduced skin bacterial communities would be more susceptible (i.e., less resistant to and/or tolerant of Bd infection, and frogs with skin bacterial communities augmented with the known antifungal bacterium would be less susceptible to Bd infection and chytridiomycosis. However, we also predicted that this interaction would be temperature dependent. We found a strong effect of temperature but not of skin microbial treatment on the probability and intensity of infection in Bd-exposed frogs. Whether temperature affected survival; however, it differed among our skin microbial treatment groups, with animals having more S. maltophilia on their skin surviving longer at 14 but not at

  20. Toward Understanding Phage:Host Interactions in the Rumen; Complete Genome Sequences of Lytic Phages Infecting Rumen Bacteria

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    Rosalind A. Gilbert

    2017-12-01

    Full Text Available The rumen is known to harbor dense populations of bacteriophages (phages predicted to be capable of infecting a diverse range of rumen bacteria. While bacterial genome sequencing projects are revealing the presence of phages which can integrate their DNA into the genome of their host to form stable, lysogenic associations, little is known of the genetics of phages which utilize lytic replication. These phages infect and replicate within the host, culminating in host lysis, and the release of progeny phage particles. While lytic phages for rumen bacteria have been previously isolated, their genomes have remained largely uncharacterized. Here we report the first complete genome sequences of lytic phage isolates specifically infecting three genera of rumen bacteria: Bacteroides, Ruminococcus, and Streptococcus. All phages were classified within the viral order Caudovirales and include two phage morphotypes, representative of the Siphoviridae and Podoviridae families. The phage genomes displayed modular organization and conserved viral genes were identified which enabled further classification and determination of closest phage relatives. Co-examination of bacterial host genomes led to the identification of several genes responsible for modulating phage:host interactions, including CRISPR/Cas elements and restriction-modification phage defense systems. These findings provide new genetic information and insights into how lytic phages may interact with bacteria of the rumen microbiome.

  1. [Anaerobic bacteria isolated from patients with suspected anaerobic infections].

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    Ercis, Serpil; Tunçkanat, Ferda; Hasçelik, Gülşen

    2005-10-01

    The study involved 394 clinical samples sent to the Clinical Microbiology Laboratory of Hacettepe University Adult Hospital between January 1997 and May 2004 for anaerobic cultivation. Since multiple cultures from the same clinical samples of the same patient were excluded, the study was carried on 367 samples. The anaerobic cultures were performed in anaerobic jar using AnaeroGen kits (Oxoid, Basingstoke, U.K.) or GENbox (bioMérieux, Lyon, France). The isolates were identified by both classical methods and "BBL Crystal System" (Becton Dickinson, U.S.A.). While no growth was detected in 120 (32.7%) of the clinical samples studied, in 144 samples (39.2%) only aerobes, in 28 (7.6%) only anaerobes and in 75 (20.5%) of the samples both aerobes and anaerobes were isolated. The number of the anaerobic isolates was 217 from 103 samples with anaerobic growth. Of these 103 samples 15 showed single bacterial growth whereas in 88 samples multiple bacterial isolates were detected. Anaerobic isolates consisted of 92 Gram negative bacilli (Bacteroides spp. 50, Prevotella spp. 14, Porphyromonas spp. 10, Fusobacterium spp. 7, Tisierella spp. 2, unidentified 9), 57 Gram positive bacilli (Clostridium spp.17, Propionibacterium spp. 16, Lactobacillus spp. 8, Actinomyces spp. 5, Eubacterium spp. 2, Bifidobacterium adolescentis 1, Mobiluncus mulieris 1, unidentified nonspore forming rods 7), 61 Gram positive cocci (anaerobic cocci 44, microaerophilic cocci 17), and 7 Gram negative cocci (Veillonella spp.). In conclusion, in the samples studied with prediagnosis of anaerobic infection, Bacteroides spp. (23%) were the most common bacteria followed by anaerobic Gram positive cocci (20.3%) and Clostridium spp (7.8%).

  2. Ecology and evolution of viruses infecting uncultivated SUP05 bacteria as revealed by single-cell- and meta-genomics.

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    Roux, Simon; Hawley, Alyse K; Torres Beltran, Monica; Scofield, Melanie; Schwientek, Patrick; Stepanauskas, Ramunas; Woyke, Tanja; Hallam, Steven J; Sullivan, Matthew B

    2014-08-29

    Viruses modulate microbial communities and alter ecosystem functions. However, due to cultivation bottlenecks, specific virus-host interaction dynamics remain cryptic. In this study, we examined 127 single-cell amplified genomes (SAGs) from uncultivated SUP05 bacteria isolated from a model marine oxygen minimum zone (OMZ) to identify 69 viral contigs representing five new genera within dsDNA Caudovirales and ssDNA Microviridae. Infection frequencies suggest that ∼1/3 of SUP05 bacteria is viral-infected, with higher infection frequency where oxygen-deficiency was most severe. Observed Microviridae clonality suggests recovery of bloom-terminating viruses, while systematic co-infection between dsDNA and ssDNA viruses posits previously unrecognized cooperation modes. Analyses of 186 microbial and viral metagenomes revealed that SUP05 viruses persisted for years, but remained endemic to the OMZ. Finally, identification of virus-encoded dissimilatory sulfite reductase suggests SUP05 viruses reprogram their host's energy metabolism. Together, these results demonstrate closely coupled SUP05 virus-host co-evolutionary dynamics with the potential to modulate biogeochemical cycling in climate-critical and expanding OMZs.

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

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    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

  4. Susceptibility to rifaximin and other antimicrobial agents of bacteria isolated from acute gastrointestinal infections in Mexico

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    O. Novoa-Farías

    2016-01-01

    Conclusions: Resistance of enteropathogenic bacteria to various antibiotics used in gastrointestinal infections is high. Rifaximin was active against 99-100% of these enteropathogens at reachable concentrations in the intestine with the recommended dose.

  5. [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.

  6. LEUKOCYTE AND BACTERIA IMAGING IN PROSTHETIC JOINT INFECTION

    NARCIS (Netherlands)

    Glaudemans, Andor W. J. M.; Galli, Filippo; Pacilio, Marta; Signore, Alberto

    2013-01-01

    There has been a significant increase in the number of joint prosthesis replacements worldwide. Although relatively uncommon, complications can occur with the most serious being an infection. Various radiological and nuclear imaging techniques are available to diagnose prosthetic joint infections

  7. Microbiology and management of joint and bone infections due to anaerobic bacteria.

    Science.gov (United States)

    Brook, Itzhak

    2008-03-01

    To describes the microbiology, diagnosis, and management of septic arthritis and osteomyelitis due to anaerobic bacteria. The predominant anaerobes in arthritis are anaerobic Gram-negative bacilli (AGNB) including the Bacteroides fragilis group, Fusobacterium spp., Peptostreptococcus spp., and Propionibacterium acnes. Infection with P. acnes is associated with a prosthetic joint, previous surgery, and trauma. B. fragilis group is associated with distant infection, Clostridium spp. with trauma, and Fusobacterium spp. with oropharyngeal infection. Most cases of anaerobic arthritis, in contrast to anaerobic osteomyelitis, involved a single isolate, and most cases are secondary to hematogenous spread. The predominant anaerobes in osteomyelitis are Bacteroides, Peptostreptococcus, Fusobacterium, and Clostridium spp. as well as P. acnes. Conditions predisposing to bone infections are vascular disease, bites, contiguous infection, peripheral neuropathy, hematogenous spread, and trauma. Pigmented Prevotella and Porphyromonas spp. are mostly isolated in skull and bite infections, members of the B. fragilis group in hand and feet infections, and Fusobacterium spp. in skull, bite, and hematogenous long bone infections. Many patients with osteomyelitis due to anaerobic bacteria have evidence of an anaerobic infection elsewhere in the body that is the source of the organisms involved in the osteomyelitis. Treatment of arthritis and osteomyelitis involving anaerobic bacteria includes symptomatic therapy, immobilization in some cases, adequate drainage of purulent material, and antibiotic therapy effective against these organisms. Anaerobic bacteria can cause septic arthritis and osteomyelitis. Correct diagnosis and appropriate therapy are important contributor to successful outcome.

  8. Does virus-bacteria coinfection increase the clinical severity of acute respiratory infection?

    Science.gov (United States)

    Damasio, Guilherme A C; Pereira, Luciane A; Moreira, Suzana D R; Duarte dos Santos, Claudia N; Dalla-Costa, Libera M; Raboni, Sonia M

    2015-09-01

    This retrospective cohort study investigated the presence of bacteria in respiratory secretions of patients hospitalized with acute respiratory infections and analyzed the impact of viral and bacterial coinfection on severity and the mortality rate. A total of 169 patients with acute respiratory infections were included, viruses and bacteria in respiratory samples were detected using molecular methods. Among all samples, 73.3% and 59.7% were positive for viruses and bacteria, respectively; 45% contained both virus and bacteria. Bacterial coinfection was more frequent in patients infected by community respiratory viruses than influenza A H1N1pdm (83.3% vs. 40.6%). The most frequently bacteria detected were Streptococcus pneumoniae and Haemophilus influenzae. Both species were co-detected in 54 patients and identified alone in 22 and 21 patients, respectively. Overall, there were no significant differences in the period of hospitalization, severity, or mortality rate between patients infected with respiratory viruses alone and those coinfected by viruses and bacteria. The detection of mixed respiratory pathogens is frequent in hospitalized patients with acute respiratory infections, but its impact on the clinical outcome does not appear substantial. However, it should be noted that most of the patients received broad-spectrum antibiotic therapy, which may have contributed to this favorable outcome. © 2015 Wiley Periodicals, Inc.

  9. Heterogeneous Family of Cyclomodulins: Smart Weapons That Allow Bacteria to Hijack the Eukaryotic Cell Cycle and Promote Infections

    Directory of Open Access Journals (Sweden)

    Rachid A. El-Aouar Filho

    2017-05-01

    Full Text Available Some bacterial pathogens modulate signaling pathways of eukaryotic cells in order to subvert the host response for their own benefit, leading to successful colonization and invasion. Pathogenic bacteria produce multiple compounds that generate favorable conditions to their survival and growth during infection in eukaryotic hosts. Many bacterial toxins can alter the cell cycle progression of host cells, impairing essential cellular functions and impeding host cell division. This review summarizes current knowledge regarding cyclomodulins, a heterogeneous family of bacterial effectors that induce eukaryotic cell cycle alterations. We discuss the mechanisms of actions of cyclomodulins according to their biochemical properties, providing examples of various cyclomodulins such as cycle inhibiting factor, γ-glutamyltranspeptidase, cytolethal distending toxins, shiga toxin, subtilase toxin, anthrax toxin, cholera toxin, adenylate cyclase toxins, vacuolating cytotoxin, cytotoxic necrotizing factor, Panton-Valentine leukocidin, phenol soluble modulins, and mycolactone. Special attention is paid to the benefit provided by cyclomodulins to bacteria during colonization of the host.

  10. Modulation of Neutrophil Extracellular Trap and Reactive Oxygen Species Release by Periodontal Bacteria.

    Science.gov (United States)

    Hirschfeld, Josefine; White, Phillipa C; Milward, Michael R; Cooper, Paul R; Chapple, Iain L C

    2017-12-01

    Oral bacteria are the main trigger for the development of periodontitis, and some species are known to modulate neutrophil function. This study aimed to explore the release of neutrophil extracellular traps (NETs), associated antimicrobial proteins, and reactive oxygen species (ROS) in response to periodontal bacteria, as well as the underlying pathways. Isolated peripheral blood neutrophils were stimulated with 19 periodontal bacteria. NET and ROS release, as well as the expression of NET-bound antimicrobial proteins, elastase, myeloperoxidase, and cathepsin G, in response to these species was measured using fluorescence-based assays. NET and ROS release was monitored after the addition of NADP (NADPH) oxidase pathway modulators and inhibitors of Toll-like receptors (TLRs). Moreover, bacterial entrapment by NETs was visualized microscopically, and bacterial killing was assessed by bacterial culture. Certain microorganisms, e.g., Veillonella parvula and Streptococcus gordonii , stimulated higher levels of ROS and NET release than others. NETs were found to entrap, but not kill, all periodontal bacteria tested. NADPH oxidase pathway modulators decreased ROS production but not NET production in response to the bacteria. Interestingly, TLR inhibitors did not impact ROS and NET release. These data suggest that the variability in the neutrophil response toward different bacteria may contribute to the pathogenesis of periodontal diseases by mechanisms such as bacterial avoidance of host responses and activation of neutrophils. Moreover, our results indicate that bacterium-stimulated NET release may arise in part via NADPH oxidase-independent mechanisms. The role of TLR signaling in bacterium-induced ROS and NET release needs to be further elucidated. Copyright © 2017 American Society for Microbiology.

  11. Bacteria Facilitate Enteric Virus Co-infection of Mammalian Cells and Promote Genetic Recombination.

    Science.gov (United States)

    Erickson, Andrea K; Jesudhasan, Palmy R; Mayer, Melinda J; Narbad, Arjan; Winter, Sebastian E; Pfeiffer, Julie K

    2018-01-10

    RNA viruses exist in genetically diverse populations due to high levels of mutations, many of which reduce viral fitness. Interestingly, intestinal bacteria can promote infection of several mammalian enteric RNA viruses, but the mechanisms and consequences are unclear. We screened a panel of 41 bacterial strains as a platform to determine how different bacteria impact infection of poliovirus, a model enteric virus. Most bacterial strains, including those extracted from cecal contents of mice, bound poliovirus, with each bacterium binding multiple virions. Certain bacterial strains increased viral co-infection of mammalian cells even at a low virus-to-host cell ratio. Bacteria-mediated viral co-infection correlated with bacterial adherence to cells. Importantly, bacterial strains that induced viral co-infection facilitated genetic recombination between two different viruses, thereby removing deleterious mutations and restoring viral fitness. Thus, bacteria-virus interactions may increase viral fitness through viral recombination at initial sites of infection, potentially limiting abortive infections. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Procalcitonin levels in bloodstream infections caused by different sources and species of bacteria.

    Science.gov (United States)

    Yan, Sheng Tao; Sun, Li Chao; Jia, Hong Bing; Gao, Wen; Yang, Jian Ping; Zhang, Guo Qiang

    2017-04-01

    The aim of this study was to evaluate procalcitonin (PCT) diagnostic accuracy in discriminating gram-negative (GN) from gram-positive (GP) bloodstream infections and determining the relationship between PCT levels, infection sites, and pathogen types. Clinical and laboratory data were collected from patients with blood culture (BC)-positive sepsis between January 2014 and December 2015. PCT levels at different infection sites were compared, as was the presence of GN and GP bloodstream infection. A receiver operating characteristic (ROC) curve was generated to assess diagnostic accuracy. Of the 486 monomicrobial BCs, 254 (52.26%) were positive for GN bacteria (GNB), and 202 (42.18%) for GP bacteria (GPB). Median PCT levels were higher in BCs positive for GN (2.42ng/ml, IQR: 0.38-15.52) than in those positive for GPB (0.49ng/ml, IQR: 0.13-5.89) (PAcinetobacter baumanni/Burkholderia cepacia, Klebsiella pneumonia and Acinetobacter baumanni. PCT levels caused by GPB differed between Staphylococcus epidermidis/Staphylococcus aureus and Staphylococcus hominis/Staphylococcus haemolyticus, Enterococcus faecium and Enterococcus faecalis/S.hominis/S. haemolyticus. Among patients with known infection sites, there were statistical differences in PCT levels between abdominal infection and pneumonia/infective endocarditis, urinary tract infection and pneumonia/catheter-related infection/infective endocarditis. PCT can distinguish between GNB and GPB infection, as well as between different bacterial species and infection sites. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  13. Antibiotic Susceptibility Pattern of Aerobic and Anaerobic Bacteria Isolated From Surgical Site Infection of Hospitalized Patients.

    Science.gov (United States)

    Akhi, Mohammad Taghi; Ghotaslou, Reza; Beheshtirouy, Samad; Asgharzadeh, Mohammad; Pirzadeh, Tahereh; Asghari, Babak; Alizadeh, Naser; Toloue Ostadgavahi, Ali; Sorayaei Somesaraei, Vida; Memar, Mohammad Yousef

    2015-07-01

    Surgical Site Infections (SSIs) are infections of incision or deep tissue at operation sites. These infections prolong hospitalization, delay wound healing, and increase the overall cost and morbidity. This study aimed to investigate anaerobic and aerobic bacteria prevalence in surgical site infections and determinate antibiotic susceptibility pattern in these isolates. One hundred SSIs specimens were obtained by needle aspiration from purulent material in depth of infected site. These specimens were cultured and incubated in both aerobic and anaerobic condition. For detection of antibiotic susceptibility pattern in aerobic and anaerobic bacteria, we used disk diffusion, agar dilution, and E-test methods. A total of 194 bacterial strains were isolated from 100 samples of surgical sites. Predominant aerobic and facultative anaerobic bacteria isolated from these specimens were the members of Enterobacteriaceae family (66, 34.03%) followed by Pseudomonas aeruginosa (26, 13.4%), Staphylococcus aureus (24, 12.37%), Acinetobacter spp. (18, 9.28%), Enterococcus spp. (16, 8.24%), coagulase negative Staphylococcus spp. (14, 7.22%) and nonhemolytic streptococci (2, 1.03%). Bacteroides fragilis (26, 13.4%), and Clostridium perfringens (2, 1.03%) were isolated as anaerobic bacteria. The most resistant bacteria among anaerobic isolates were B. fragilis. All Gram-positive isolates were susceptible to vancomycin and linezolid while most of Enterobacteriaceae showed sensitivity to imipenem. Most SSIs specimens were polymicrobial and predominant anaerobic isolate was B. fragilis. Isolated aerobic and anaerobic strains showed high level of resistance to antibiotics.

  14. [Flesh-eating bacteria infection of an immunocompromised patient].

    Science.gov (United States)

    Slavei, K; Hauser, B; Pénzes, I; Ondrejka, P; Faller, J

    2001-10-01

    After years of steadily declining morbidity and mortality due to group A streptococcal infections, a resurgence of severe, invasive disease has been ongoing since 1980, leading to the recognition of streptococcal shock syndrome (STSS), necrotizing fasciitis, the most severe form of invasive infection. The patients suffer from rapid local deep soft tissue destruction, severe septic shock and multi organ failure. The increased incidence of these infections has been accompanied by remarkable vigor in virulence and severity of the disease. The reason for this impressive change in the epidemiology and clinical manifestation of group A streptococcal infections remains unknown. The possible etiological factor is changing in virulence factor or the lack of protective immunity of the population (immunocompromise) against the invasive strains. We describe a severe necrotizing fasciitis of a 41-year-old previously immunocompromised woman. The patient developed severe septic shock, multi organ failure and perineal and lower abdominal skin, fat and fascia necrosis due to mixed GAS (aerob, anaerob) infection of the perineum and the Bartholini glands. After an aggressive surgical debridement, antibiotic and supportive therapy the generalised and local infection was treated.

  15. Increased number of anaerobic bacteria in the infected root canal in type 2 diabetic rats.

    Science.gov (United States)

    Iwama, Akihiro; Morimoto, Taisuke; Tsuji, Masahito; Nakamura, Koki; Higuchi, Naoya; Imaizumi, Ichiro; Shibata, Naoki; Yamasaki, Masahiro; Nakamura, Hiroshi

    2006-05-01

    The purpose of this study was to investigate the relationship between type 2 diabetes mellitus and anaerobic bacteria detected in infected root canals. Normal Wistar rats (control) received a standard laboratory diet with water (group A), and GK rats (type 2 diabetes mellitus rats) a normal laboratory diet with water (group B) or a 30% sucrose solution (group C). Chemotaxis assay was conducted on polymorphonuclear leukocytes from the 3 groups, and the numbers of anaerobic bacteria in infected root canals were determined. In the chemotaxis assay on the polymorphonuclear leukocytes, the chemotactic response of cells in group C was lower than that for groups A and B (P obligate anaerobic bacteria which stained gram negative, were significantly more numerous in group C (P < .01) than in groups A and B. The metabolic condition produced by type 2 diabetes mellitus in rats might lower the general host resistance against bacterial infection.

  16. Why sensitive bacteria are resistant to hospital infection control.

    Science.gov (United States)

    van Kleef, Esther; Luangasanatip, Nantasit; Bonten, Marc J; Cooper, Ben S

    2017-01-01

    Large reductions in the incidence of antibiotic-resistant strains of Staphylococcus aureus and Clostridium difficile have been observed in response to multifaceted hospital-based interventions. Reductions in antibiotic-sensitive strains have been smaller or non-existent. It has been argued that since infection control measures, such as hand hygiene, should affect resistant and sensitive strains equally, observed changes must have largely resulted from other factors, including changes in antibiotic use. We used a mathematical model to test the validity of this reasoning. We developed a mechanistic model of resistant and sensitive strains in a hospital and its catchment area. We assumed the resistant strain had a competitive advantage in the hospital and the sensitive strain an advantage in the community. We simulated a hospital hand hygiene intervention that directly affected resistant and sensitive strains equally. The annual incidence rate ratio (IRR) associated with the intervention was calculated for hospital- and community-acquired infections of both strains. For the resistant strain, there were large reductions in hospital-acquired infections (0.1 ≤ IRR ≤ 0.6) and smaller reductions in community-acquired infections (0.2 ≤ IRR ≤ 0.9). These reductions increased in line with increasing importance of nosocomial transmission of the strain. For the sensitive strain, reductions in hospital acquisitions were much smaller (0.6 ≤ IRR ≤ 0.9), while community acquisitions could increase or decrease (0.9 ≤ IRR ≤ 1.2). The greater the importance of the community environment for the transmission of the sensitive strain, the smaller the reductions. Counter-intuitively, infection control interventions, including hand hygiene, can have strikingly discordant effects on resistant and sensitive strains even though they target them equally. This follows from differences in their adaptation to hospital- and community-based transmission. Observed lack of

  17. Multidrug-resistant bacteria infection and nursing quality management application in the department of physical examination.

    Science.gov (United States)

    Xu, Li; Luo, Qiang; Chen, Liangzhen; Jiao, Lingmei

    2017-09-01

    The main problem of clinical prevention and control of multi drug resistant bacteria infection is to strengthen the monitoring of pathogenic bacteria spectrum, this study research on the multi drug-resistant bacteria infection and nursing quality management application in the department of physical examination. The results of this study showed that the number of patients with multiple drug resistant infections showed an increasing trend. Therefore, once the patients with multiple drug-resistant bacteria infection are found, the prevention and control of the patients with multiple drug-resistant bacteria should be strictly followed, and the patient's medication care should be highly valued. Also, the nurses need to be classified based on the knowledge and skill characteristics of the nurses in the department of physical examination, and compare the nursing effect before and after classification and grouping. The physicians and individuals receiving physical examinations in the department of physical examination had a higher degree of satisfaction for nursing effect after classification compared with those before classification. Classification and grouping management helps improve the nursing quality and overall quality of the nurses in the department of physical examination.

  18. Metallothioneins: Emerging Modulators in Immunity and Infection

    Directory of Open Access Journals (Sweden)

    Kavitha Subramanian Vignesh

    2017-10-01

    Full Text Available Metallothioneins (MTs are a family of metal-binding proteins virtually expressed in all organisms including prokaryotes, lower eukaryotes, invertebrates and mammals. These proteins regulate homeostasis of zinc (Zn and copper (Cu, mitigate heavy metal poisoning, and alleviate superoxide stress. In recent years, MTs have emerged as an important, yet largely underappreciated, component of the immune system. Innate and adaptive immune cells regulate MTs in response to stress stimuli, cytokine signals and microbial challenge. Modulation of MTs in these cells in turn regulates metal ion release, transport and distribution, cellular redox status, enzyme function and cell signaling. While it is well established that the host strictly regulates availability of metal ions during microbial pathogenesis, we are only recently beginning to unravel the interplay between metal-regulatory pathways and immunological defenses. In this perspective, investigation of mechanisms that leverage the potential of MTs to orchestrate inflammatory responses and antimicrobial defenses has gained momentum. The purpose of this review, therefore, is to illumine the role of MTs in immune regulation. We discuss the mechanisms of MT induction and signaling in immune cells and explore the therapeutic potential of the MT-Zn axis in bolstering immune defenses against pathogens.

  19. A Legume Genetic Framework Controls Infection of Nodules by Symbiotic and Endophytic Bacteria

    Science.gov (United States)

    Zgadzaj, Rafal; James, Euan K.; Kelly, Simon; Kawaharada, Yasuyuki; de Jonge, Nadieh; Jensen, Dorthe B.; Madsen, Lene H.; Radutoiu, Simona

    2015-01-01

    Legumes have an intrinsic capacity to accommodate both symbiotic and endophytic bacteria within root nodules. For the symbionts, a complex genetic mechanism that allows mutual recognition and plant infection has emerged from genetic studies under axenic conditions. In contrast, little is known about the mechanisms controlling the endophytic infection. Here we investigate the contribution of both the host and the symbiotic microbe to endophyte infection and development of mixed colonised nodules in Lotus japonicus. We found that infection threads initiated by Mesorhizobium loti, the natural symbiont of Lotus, can selectively guide endophytic bacteria towards nodule primordia, where competent strains multiply and colonise the nodule together with the nitrogen-fixing symbiotic partner. Further co-inoculation studies with the competent coloniser, Rhizobium mesosinicum strain KAW12, show that endophytic nodule infection depends on functional and efficient M. loti-driven Nod factor signalling. KAW12 exopolysaccharide (EPS) enabled endophyte nodule infection whilst compatible M. loti EPS restricted it. Analysis of plant mutants that control different stages of the symbiotic infection showed that both symbiont and endophyte accommodation within nodules is under host genetic control. This demonstrates that when legume plants are exposed to complex communities they selectively regulate access and accommodation of bacteria occupying this specialized environmental niche, the root nodule. PMID:26042417

  20. Infection Vibrio sp. Bacteria on Kappaphycus Seaweed Varieties Brown and Green

    Science.gov (United States)

    Irmawati, Yuni; Sudirjo, Fien

    2017-10-01

    Disease in seaweed or ice-ice, until today is still a major problem in the cultivation of seaweed. Changes in extreme environmental conditions is a trigger factor of ice-ice, which can result in seaweed susceptible to infection with pathogenic microorganisms, such as bacteria Vibrio sp. This research aims to determine the bacteria Vibrio sp. infection in seaweed Kappaphycus varieties of brown and green. Vibrio sp. bacteria isolated in the infected seaweed thallus ice-ice, grown on TCBS media, purification, gram staining and biochemical tests. Vibrio sp. infected to seaweed Kappaphycus brown and green varieties in containers controlled by different density, 105 CFU/ml, 106 CFU/ml and 107CFU/ml. Observations were made to change clinical effect in thallus seaweed for 14 days of observation. The results obtained show that the levels of infection bacteria Vibrio sp. higher in seaweed Kappaphycus green varieties both in density 105 CFU/ml, 106 CFU/ml and 107CFU/ml, when compared with varieties brown.

  1. Why sensitive bacteria are resistant to hospital infection control

    Science.gov (United States)

    van Kleef, Esther; Luangasanatip, Nantasit; Bonten, Marc J; Cooper, Ben S

    2017-01-01

    Background: Large reductions in the incidence of antibiotic-resistant strains of Staphylococcus aureus and Clostridium difficile have been observed in response to multifaceted hospital-based interventions. Reductions in antibiotic-sensitive strains have been smaller or non-existent. It has been argued that since infection control measures, such as hand hygiene, should affect resistant and sensitive strains equally, observed changes must have largely resulted from other factors, including changes in antibiotic use. We used a mathematical model to test the validity of this reasoning. Methods: We developed a mechanistic model of resistant and sensitive strains in a hospital and its catchment area. We assumed the resistant strain had a competitive advantage in the hospital and the sensitive strain an advantage in the community. We simulated a hospital hand hygiene intervention that directly affected resistant and sensitive strains equally. The annual incidence rate ratio ( IRR) associated with the intervention was calculated for hospital- and community-acquired infections of both strains. Results: For the resistant strain, there were large reductions in hospital-acquired infections (0.1 ≤ IRR ≤ 0.6) and smaller reductions in community-acquired infections (0.2 ≤ IRR ≤  0.9). These reductions increased in line with increasing importance of nosocomial transmission of the strain. For the sensitive strain, reductions in hospital acquisitions were much smaller (0.6 ≤ IRR ≤ 0.9), while communityacquisitions could increase or decrease (0.9 ≤ IRR ≤ 1.2). The greater the importance of the community environment for the transmission of the sensitive strain, the smaller the reductions. Conclusions: Counter-intuitively, infection control interventions, including hand hygiene, can have strikingly discordant effects on resistant and sensitive strains even though they target them equally, following differences in their adaptation to hospital and community

  2. Significance of anaerobic bacteria in postoperative infection after radical cystectomy and urinary diversion or reconstruction.

    Science.gov (United States)

    Hiyama, Yoshiki; Takahashi, Satoshi; Uehara, Teruhisa; Hashimoto, Jiro; Kurimura, Yuichiro; Tanaka, Toshiaki; Masumori, Naoya; Tsukamoto, Taiji

    2013-10-01

    Radical cystectomy followed by urinary diversion or reconstruction (RC) is a standard treatment for patients with muscle-invasive bladder cancer. In these operations, a high frequency of complications, especially postoperative infection, has been reported. However, there have only been a few studies about postoperative anaerobic bacterial infection. To clarify the significance and role of anaerobic bacteria in postoperative infection, we retrospectively analyzed cases in which postoperative infection by these organisms developed. A total of 126 patients who underwent RC from 2006 to 2010 were included in this study. Various types of postoperative infection occurred in 66 patients. Anaerobic bacterial infections were detected with cultures for urine and blood in one case, for blood in two cases, and for surgical wound pus in four. The frequency of postoperative anaerobic bacterial infection in RC was less than that of colon surgery. However, this study revealed the possible development of a nonnegligible number of postoperative anaerobic bacterial infections. Therefore, we should consider anaerobic bacteria as possible pathogens in postoperative infection after RC.

  3. Gamma-aminobutyric acid-modulated benzodiazepine binding sites in bacteria

    International Nuclear Information System (INIS)

    Lummis, S.C.R.; Johnston, G.A.R.; Nicoletti, G.; Holan, G.

    1991-01-01

    Benzodiazepine binding sites, which were once considered to exist only in higher vertebrates, are here demonstrated in the bacteria E. coli. The bacterial [ 3 H]diazepam binding sites are modulated by GABA; the modulation is dose dependent and is reduced at high concentrations. The most potent competitors of E.Coli [ 3 H]diazepam binding are those that are active in displacing [ 3 H]benzodiazepines from vertebrate peripheral benzodiazepine binding sites. These vertebrate sites are not modulated by GABA, in contrast to vertebrate neuronal benzodiazepine binding sites. The E.coli benzodiazepine binding sites therefore differ from both classes of vertebrate benzodiazepine binding sites; however the ligand spectrum and GABA-modulatory properties of the E.coli sites are similar to those found in insects. This intermediate type of receptor in lower species suggests a precursor for at least one class of vertebrate benzodiazepine binding sites may have existed

  4. Network analysis reveals that bacteria and fungi form modules that correlate independently with soil parameters.

    Science.gov (United States)

    de Menezes, Alexandre B; Prendergast-Miller, Miranda T; Richardson, Alan E; Toscas, Peter; Farrell, Mark; Macdonald, Lynne M; Baker, Geoff; Wark, Tim; Thrall, Peter H

    2015-08-01

    Network and multivariate statistical analyses were performed to determine interactions between bacterial and fungal community terminal restriction length polymorphisms as well as soil properties in paired woodland and pasture sites. Canonical correspondence analysis (CCA) revealed that shifts in woodland community composition correlated with soil dissolved organic carbon, while changes in pasture community composition correlated with moisture, nitrogen and phosphorus. Weighted correlation network analysis detected two distinct microbial modules per land use. Bacterial and fungal ribotypes did not group separately, rather all modules comprised of both bacterial and fungal ribotypes. Woodland modules had a similar fungal : bacterial ribotype ratio, while in the pasture, one module was fungal dominated. There was no correspondence between pasture and woodland modules in their ribotype composition. The modules had different relationships to soil variables, and these contrasts were not detected without the use of network analysis. This study demonstrated that fungi and bacteria, components of the soil microbial communities usually treated as separate functional groups as in a CCA approach, were co-correlated and formed distinct associations in these adjacent habitats. Understanding these distinct modular associations may shed more light on their niche space in the soil environment, and allow a more realistic description of soil microbial ecology and function. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

  5. Modulation of PML protein expression regulates JCV infection

    International Nuclear Information System (INIS)

    Gasparovic, Megan L.; Maginnis, Melissa S.; O'Hara, Bethany A.; Dugan, Aisling S.; Atwood, Walter J.

    2009-01-01

    JC virus (JCV) is a human polyomavirus that infects the majority of the human population worldwide. It is responsible for the fatal demyelinating disease Progressive Multifocal Leukoencephalopathy. JCV binds to cells using the serotonin receptor 5-HT 2A R and α(2-6)- or α(2-3)-linked sialic acid. It enters cells using clathrin-dependent endocytosis and traffics to the early endosome and possibly to the endoplasmic reticulum. Viral DNA is then delivered to the nucleus where transcription, replication, and assembly of progeny occur. We found that the early regulatory protein large T antigen accumulates in microdomains in the nucleus adjacent to ND-10 or PML domains. This observation prompted us to explore the role of these domains in JCV infection. We found that a reduction of nuclear PML enhanced virus infection and that an increase in nuclear PML reduced infection. Infection with JCV did not directly modulate nuclear levels of PML but our data indicate that a host response involving interferon beta is likely to restrict virus infection by increasing nuclear PML.

  6. Antibacterial activity of Pinus elliottii against anaerobic bacteria present in primary endodontic infections.

    Science.gov (United States)

    Caetano da Silva, Sandro Donizete; Mendes de Souza, Maria Gorete; Oliveira Cardoso, Miguel Jorge; da Silva Moraes, Thais; Ambrósio, Sérgio Ricardo; Sola Veneziani, Rodrigo Cássio; Martins, Carlos Henrique G

    2014-12-01

    Endodontic infections have a polymicrobial nature, but anaerobic bacteria prevail among the infectious microbes. Considering that it is easy to eliminate planktonic bacteria, biofilm-forming bacteria still challenge clinicians during the fight against endodontic diseases. The chemical constituents of the oleoresin of Pinus elliottii, a plant belonging to the family Pinaceae, stand out in the search for biologically active compounds based on natural products with potential application in the treatment of endodontic infections. Indeed, plant oleoresins are an abundant natural source of diterpenes that display significant and well-defined biological activities as well as potential antimicrobial action. In this context, this study aimed to (1) evaluate the in vitro antibacterial activity of the oleoresin, fractions, and subfractions of P. elliottii as well as the action of dehydroabietic acid against 11 anaerobic bacteria that cause endodontic infection in both their planktonic and biofilm forms and (2) assess the in vitro antibiofilm activity of dehydroabietic acid against the same group of bacteria. The broth microdilution technique helped to determine the minimum inhibitory concentration (MIC) of the oleoresin and fractions. This same technique aided determination of the MIC values of nine subfractions of Fraction 1, the most active fraction. The MIC, minimum bactericidal concentration, and antibiofilm activity of dehydroabietic acid against the tested anaerobic bacteria were also examined. The oleoresin and fractions, especially fraction PE1, afforded promising MIC values, which ranged from 0.4 to 50 μg/mL. Concerning the nine evaluated subfractions, PE1.3 and PE1.4 furnished the most noteworthy MIC values, between 6.2 and 100 μg/mL. Dehydroabietic acid displayed antibacterial activity, with MIC values lying from 6.2 to 50 μg/mL, as well as bactericidal effect for all the investigated bacteria, except for Prevotella nigrescens. Assessment of the antibiofilm

  7. Antibiotic management of lung infections in cystic fibrosis. II. Nontuberculous mycobacteria, anaerobic bacteria, and fungi.

    Science.gov (United States)

    Chmiel, James F; Aksamit, Timothy R; Chotirmall, Sanjay H; Dasenbrook, Elliott C; Elborn, J Stuart; LiPuma, John J; Ranganathan, Sarath C; Waters, Valerie J; Ratjen, Felix A

    2014-10-01

    Airway infections are a key component of cystic fibrosis (CF) lung disease. Whereas the approach to common pathogens such as Pseudomonas aeruginosa is guided by a significant body of evidence, other infections often pose a considerable challenge to treating physicians. In Part I of this series on the antibiotic management of difficult lung infections, we discussed bacterial organisms including methicillin-resistant Staphylococcus aureus, gram-negative bacterial infections, and treatment of multiple bacterial pathogens. Here, we summarize the approach to infections with nontuberculous mycobacteria, anaerobic bacteria, and fungi. Nontuberculous mycobacteria can significantly impact the course of lung disease in patients with CF, but differentiation between colonization and infection is difficult clinically as coinfection with other micro-organisms is common. Treatment consists of different classes of antibiotics, varies in intensity, and is best guided by a team of specialized clinicians and microbiologists. The ability of anaerobic bacteria to contribute to CF lung disease is less clear, even though clinical relevance has been reported in individual patients. Anaerobes detected in CF sputum are often resistant to multiple drugs, and treatment has not yet been shown to positively affect patient outcome. Fungi have gained significant interest as potential CF pathogens. Although the role of Candida is largely unclear, there is mounting evidence that Scedosporium species and Aspergillus fumigatus, beyond the classical presentation of allergic bronchopulmonary aspergillosis, can be relevant in patients with CF and treatment should be considered. At present, however there remains limited information on how best to select patients who could benefit from antifungal therapy.

  8. [Intestinal disorder of anaerobic bacteria aggravates pulmonary immune pathological injury of mice infected with influenza virus].

    Science.gov (United States)

    Wu, Sha; Yan, Yuqi; Zhang, Mengyuan; Shi, Shanshan; Jiang, Zhenyou

    2016-04-01

    To investigate the relationship between the intestinal disorder of anaerobic bacteria and influenza virus infection, and the effect on pulmonary inflammatory cytokines in mice. Totally 36 mice were randomly divided into normal control group, virus-infected group and metronidazole treatment group (12 mice in each group). Mice in the metronidazole group were administrated orally with metronidazole sulfate for 8 days causing anaerobic bacteria flora imbalance; then all groups except the normal control group were treated transnasally with influenza virus (50 μL/d FM1) for 4 days to establish the influenza virus-infected models. Their mental state and lung index were observed, and the pathological morphological changes of lung tissues, caecum and intestinal mucosa were examined by HE staining. The levels of interleukin 4 (IL-4), interferon γ (IFN-γ), IL-10 and IL-17 in the lung homogenates were determined by ELISA. Compared with the virus control group, the metronidazole group showed obviously increased lung index and more serious pathological changes of the lung tissue and appendix inflammation performance. After infected by the FM1 influenza virus, IFN-γ and IL-17 of the metronidazole group decreased significantly and IL-4 and IL-10 levels were raised, but there was no statistically difference between the metronidazole and virus control groups. Intestinal anaerobic bacteria may inhibit the adaptive immune response in the lungs of mice infected with FM1 influenza virus through adjusting the lung inflammatory factors, affect the replication and clean-up time of the FM1 influenza virus, thus further aggravating pulmonary immune pathological injury caused by the influenza virus infection.

  9. Isolation and life cycle characterization of lytic viruses infecting heterotrophic bacteria and cyanobacteria

    DEFF Research Database (Denmark)

    Middelboe, Mathias; Chan, Amy; Bertelsen, Sif Koldborg

    2010-01-01

    Basic knowledge on viruses infecting heterotrophic bacteria and cyanobacteria is key to future progress in understanding the role of viruses in aquatic systems and the influence of virus–host interactions on microbial mortality, biogeochemical cycles, and genetic exchange. Such studies require......, and discusses the applications and limitations of different isolation procedures. Most work on phage isolation has been carried out with aerobic heterotrophic bacteria and cyanobacteria, culturable both on agar plates and in enriched liquid cultures. The procedures presented here are limited to lytic viruses...... infecting such hosts. In addition to the isolation procedures, methods for life cycle characterization (one-step growth experiments) of bacteriophages and cyanophages are described. Finally, limitations and drawbacks of the proposed methods are assessed and discussed...

  10. Non-destructive evaluation of bacteria-infected watermelon seeds using visible/near-infrared hyperspectral imaging.

    Science.gov (United States)

    Lee, Hoonsoo; Kim, Moon S; Song, Yu-Rim; Oh, Chang-Sik; Lim, Hyoun-Sub; Lee, Wang-Hee; Kang, Jum-Soon; Cho, Byoung-Kwan

    2017-03-01

    There is a need to minimize economic damage by sorting infected seeds from healthy seeds before seeding. However, current methods of detecting infected seeds, such as seedling grow-out, enzyme-linked immunosorbent assays, the polymerase chain reaction (PCR) and the real-time PCR have a critical drawbacks in that they are time-consuming, labor-intensive and destructive procedures. The present study aimed to evaluate the potential of visible/near-infrared (Vis/NIR) hyperspectral imaging system for detecting bacteria-infected watermelon seeds. A hyperspectral Vis/NIR reflectance imaging system (spectral region of 400-1000 nm) was constructed to obtain hyperspectral reflectance images for 336 bacteria-infected watermelon seeds, which were then subjected to partial least square discriminant analysis (PLS-DA) and a least-squares support vector machine (LS-SVM) to classify bacteria-infected watermelon seeds from healthy watermelon seeds. The developed system detected bacteria-infected watermelon seeds with an accuracy > 90% (PLS-DA: 91.7%, LS-SVM: 90.5%), suggesting that the Vis/NIR hyperspectral imaging system is effective for quarantining bacteria-infected watermelon seeds. The results of the present study show that it is possible to use the Vis/NIR hyperspectral imaging system for detecting bacteria-infected watermelon seeds. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  11. Staphylococcus aureus effect of different factors on mammary gland infection with staphylococcus aureus bacteria

    Directory of Open Access Journals (Sweden)

    Jurčevič Alen

    2004-01-01

    Full Text Available The objective of our investigation was to determine how certain factors (the environment, treatment, prevention, animal affect udder infection with Staphylococcus aureurs (S. aureus bacteria. A questionnaire investigated the effect of different factors on the frequency of infection with S. aureus bacteria. We established that prevention, treatment on the basis of results of bacteriological examinations and antibiograms, and the elimination of the negative influence of the environment, form a basis for reducing the frequency of udder infections. We verified the questionannire results with the variant analysis method and established that the effect of the environment significantly digresses from the other factors (prevention treatment and diagnosis, animal. Our results show that the breeder, with good prevention and good treatment of mastitis, often disregards the effects of the barn and the environment in which the cows are maintained. Poor barn conditions have a negative effect on cow resistance and at the same time enable the existence and multiplication of pathogenic species of bacteria. In addition to the maintenance conditions, one must not forget prevention and therapy of mammary gland inflammation, either. On the grounds of our previous investigations (Pengov et al., 2000, we recommend for the therapy of mammary gland inflammation the use of a combination of amoxicillin and clavulonic acid, and as prevention of mammary gland inflammation the use of an udder ointment.

  12. Modulation of antigen presenting cell functions during chronic HPV infection

    Directory of Open Access Journals (Sweden)

    Abate Assefa Bashaw

    2017-12-01

    Full Text Available High-risk human papillomaviruses (HR-HPV infect basal keratinocytes, where in some individuals they evade host immune responses and persist. Persistent HR-HPV infection of the cervix causes precancerous neoplasia that can eventuate in cervical cancer. Dendritic cells (DCs are efficient in priming/cross-priming antigen-specific T cells and generating antiviral and antitumor cytotoxic CD8+ T cells. However, HR-HPV have adopted various immunosuppressive strategies, with modulation of DC function crucial to escape from the host adaptive immune response. HPV E6 and E7 oncoproteins alter recruitment and localization of epidermal DCs, while soluble regulatory factors derived from HPV-induced hyperplastic epithelium change DC development and influence initiation of specific cellular immune responses. This review focuses on current evidence for HR-HPV manipulation of antigen presentation in dendritic cells and escape from host immunity.

  13. Multiplicity of Mathematical Modeling Strategies to Search for Molecular and Cellular Insights into Bacteria Lung Infection.

    Science.gov (United States)

    Cantone, Martina; Santos, Guido; Wentker, Pia; Lai, Xin; Vera, Julio

    2017-01-01

    Even today two bacterial lung infections, namely pneumonia and tuberculosis, are among the 10 most frequent causes of death worldwide. These infections still lack effective treatments in many developing countries and in immunocompromised populations like infants, elderly people and transplanted patients. The interaction between bacteria and the host is a complex system of interlinked intercellular and the intracellular processes, enriched in regulatory structures like positive and negative feedback loops. Severe pathological condition can emerge when the immune system of the host fails to neutralize the infection. This failure can result in systemic spreading of pathogens or overwhelming immune response followed by a systemic inflammatory response. Mathematical modeling is a promising tool to dissect the complexity underlying pathogenesis of bacterial lung infection at the molecular, cellular and tissue levels, and also at the interfaces among levels. In this article, we introduce mathematical and computational modeling frameworks that can be used for investigating molecular and cellular mechanisms underlying bacterial lung infection. Then, we compile and discuss published results on the modeling of regulatory pathways and cell populations relevant for lung infection and inflammation. Finally, we discuss how to make use of this multiplicity of modeling approaches to open new avenues in the search of the molecular and cellular mechanisms underlying bacterial infection in the lung.

  14. Antibacterial Effects of Citrus aurantium on Bacteria Isolated from Urinary Tract Infection

    Directory of Open Access Journals (Sweden)

    Masoud Dadashi

    2015-10-01

    Full Text Available Background :  Emerging antibacterial resistance rates and beta-lactamase producing bacteria recovered from UTI is an increasing problem in different regions, limiting therapeutic options. Therefore, this survey consider to use the extract and essence of the citrus aurantium (which have a so many rate of planting in Iran and also survey on extract on bacteria whose cause urinary tract infections, and compare this with common antibiotics. Methods and Materials: This study was experimental design.We have been isolate the E.coli,Klebsiella pneumoniae, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus agalactiae and Enterococcus faecalis from UTI and then determine of antibacterial effect of Citrus aurantium against this bacteria with subculture and put the exact diagnosis on them. Antibacterial effects of the herb extract by well diffusion assay and  nalidixic acid and Co-trimoxazol were evaluated by method of agar disc diffusion. Results:Enterococcus faecalis had 100% sensitivity against of extract,essence and Co-trimoxazole , and 80% against nalidixic acid . E.coli had 100% sensitivity against Co-trimoxazol, nalidixic acid and it was totally resistance to extract and essence.Klebsiella Pneumonie had 80% to Co-trimoxazol, 75% to nalidixic acid and resistance against extract and essence.Streptococcus agalactiae was 100% sensitivity to essence and Co-trimoxazol and 90% against nalidixic acid and shown 80% sensitivity against extract.Staphylococcus aureus MRSA shown 100% sensitivity against Co-trimoxazol and 70% sensitivity against essence, extract and nalidixic acid. Conclusion: Detection of antibiotic resistance among isolates is important in prevention and control of infections. In this study, it was shown that extracts of citrus aurantium have high antibacterial effects on gram positive bacteria compare to gram negative bacteria.

  15. Assessment of pathogenesis of infective endocarditis by plasma IgG antibody titer test against periodontal bacteria.

    Science.gov (United States)

    Isoshima, Daichi; Yamashiro, Keisuke; Matsunaga, Kazuyuki; Shinobe, Michitaka; Nakanishi, Nagako; Nakanishi, Izumi; Omori, Kazuhiro; Yamamoto, Tadashi; Takashiba, Shogo

    2017-10-01

    Oral bacteria cause infective endocarditis (IE), so severe periodontitis is thought to be high risk for IE. We suggest the identification of high-risk patients by an IgG antibody titer test against periodontal bacteria might become common screening test.

  16. Bacteriophages: the possible solution to treat infections caused by pathogenic bacteria.

    Science.gov (United States)

    El-Shibiny, Ayman; El-Sahhar, Salma

    2017-11-01

    Since their discovery in 1915, bacteriophages have been used to treat bacterial infections in animals and humans because of their unique ability to infect their specific bacterial hosts without affecting other bacterial populations. The research carried out in this field throughout the 20th century, largely in Georgia, part of USSR and Poland, led to the establishment of phage therapy protocols. However, the discovery of penicillin and sulfonamide antibiotics in the Western World during the 1930s was a setback in the advancement of phage therapy. The misuse of antibiotics has reduced their efficacy in controlling pathogens and has led to an increase in the number of antibiotic-resistant bacteria. As an alternative to antibiotics, bacteriophages have become a topic of interest with the emergence of multidrug-resistant bacteria, which are a threat to public health. Recent studies have indicated that bacteriophages can be used indirectly to detect pathogenic bacteria or directly as biocontrol agents. Moreover, they can be used to develop new molecules for clinical applications, vaccine production, drug design, and in the nanomedicine field via phage display.

  17. Microfluidic-Based Bacteria Isolation from Whole Blood for Diagnostics of Blood Stream Infection.

    Science.gov (United States)

    Zelenin, Sergey; Ramachandraiah, Harisha; Faridi, Asim; Russom, Aman

    2017-01-01

    Bacterial blood stream infection (BSI) potentially leads to life-threatening clinical conditions and medical emergencies such as severe sepsis, septic shock, and multi organ failure syndrome. Blood culturing is currently the gold standard for the identification of microorganisms and, although it has been automated over the decade, the process still requires 24-72 h to complete. This long turnaround time, especially for the identification of antimicrobial resistance, is driving the development of rapid molecular diagnostic methods. Rapid detection of microbial pathogens in blood related to bloodstream infections will allow the clinician to decide on or adjust the antimicrobial therapy potentially reducing the morbidity, mortality, and economic burden associated with BSI. For molecular-based methods, there is a lot to gain from an improved and straightforward method for isolation of bacteria from whole blood for downstream processing.We describe a microfluidic-based sample-preparation approach that rapidly and selectively lyses all blood cells while it extracts intact bacteria for downstream analysis. Whole blood is exposed to a mild detergent, which lyses most blood cells, and then to osmotic shock using deionized water, which eliminates the remaining white blood cells. The recovered bacteria are 100 % viable, which opens up possibilities for performing drug susceptibility tests and for nucleic-acid-based molecular identification.

  18. Investigational drugs for the treatment of infections caused by multidrug-resistant Gram-negative bacteria.

    Science.gov (United States)

    Avery, Lindsay M; Nicolau, David P

    2018-04-01

    Infections caused by multidrug-resistant Gram-negative bacteria (MDR-GNB) are associated with significant mortality and costs. New drugs in development to combat these difficult-to-treat infections primarily target carbapenem-resistant Enterobacteriaceae, MDR Pseudomonas aeruginosa, and MDR Acinetobacter baumannii. Areas covered: The authors summarize in vitro and in vivo efficacy studies, as well as available clinical trial findings, for new agents in development for treatment of infection caused by MDR-GNB. Information regarding dosage regimens utilized in clinical trials and key pharmacokinetic and pharmacodynamic considerations are provided if available. A summary of recently approved agents, delafloxacin and meropenem/vaborbactam, is also included. Expert opinion: The development of multiple novel agents to fight MDR-GNB is promising to help save the lives of patients who acquire infection, and judicious use of these agents is imperative once they come to market to prevent the development of resistance. The other component paramount to this field of research is implementation of effective infection control policies and carbapenem-resistant Enterobacteriaceae (CRE) carrier screening protocols to mitigate the worldwide spread of MDR-GNB. Further investigation of anti-infective synergistic combinations will also be important, as well as support for economic research to reveal the true cost-benefit of utilization of the new agents discussed herein.

  19. A prebiotic role of Ecklonia cava improves the mortality of Edwardsiella tarda-infected zebrafish models via regulating the growth of lactic acid bacteria and pathogen bacteria.

    Science.gov (United States)

    Lee, WonWoo; Oh, Jae Young; Kim, Eun-A; Kang, Nalae; Kim, Kil-Nam; Ahn, Ginnae; Jeon, You-Jin

    2016-07-01

    In this study, the beneficial prebiotic roles of Ecklonia cava (E. cava, EC) were evaluated on the growth of lactic acid bacteria (LAB) and pathogen bacteria and the mortality of pathogen-bacteria infected zebrafish model. The result showed that the original E. cava (EC) led to the highest growth effects on three LABs (Lactobacillus brevis, L. brevis; Lactobacillus pentosus, L. pentosus; Lactobacillus plantarum; L. plantarum) and it was dose-dependent manners. Also, EC, its Celluclast enzymatic (ECC) and 100% ethanol extracts (ECE) showed the anti-bacterial activities on the fish pathogenic bacteria such as (Edwardsiella tarda; E. tarda, Streptococcus iniae; S. iniae, and Vibrio harveyi; V. harveyi). Interestingly, EC induced the higher production of the secondary metabolites from L. plantarum in MRS medium. The secondary metabolites produced by EC significantly inhibited the growth of pathogen bacteria. In further in vivo study, the co-treatment of EC and L. plantarum improved the growth and mortality of E. tarda-infected zebrafish as regulating the expression of inflammatory molecules such as iNOS and COX2. Taken together, our present study suggests that the EC plays an important role as a potential prebiotic and has a protective effect against the infection caused by E. tarda injection in zebrafish. Also, our conclusion from this evidence is that EC can be used and applied as a useful prebiotic. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Characterization of Bacteria in Nigerian Yogurt as Promising Alternative to Antibiotics in Gastrointestinal Infections.

    Science.gov (United States)

    Ayeni, Anthony Opeyemi; Ruppitsch, Werner; Ayeni, Funmilola Abidemi

    2018-03-14

    Gastrointestinal infections are endemic in Nigeria and several factors contribute to their continual survival, including bacterial resistance to commonly used antibiotics. Nigerian yogurts do not include probiotics, and limited information is available about the antimicrobial properties of the fermenters in the yogurt against gastrointestinal pathogens. Therefore, the antimicrobial potentials of bacteria in Nigeria-produced yogurts against intestinal pathogens were investigated in this study. Viable counts of lactic acid bacteria (LAB) in 15 brands of yogurt were enumerated and the bacteria identified by partial sequencing of 16S rRNA gene. Susceptibility of the gastrointestinal pathogens (Salmonella, Shigella and E. coli ) to antibiotics by disc diffusion method, to viable LAB by the agar overlay method, and to the cell-free culture supernatant (CFCS) of the LAB were investigated. Co-culture analysis of LAB and pathogens were also done. Viable counts of 1.5 × 10 11 cfu/ml were observed in some yogurt samples. Two genera were identified: Lactobacillus (70.7%) and Acetobacter (29.3%). The Lactobacillus species reduced multidrug-resistant gastrointestinal pathogens by 4 to 5 log while the zones of inhibition ranged between 11 and 23. The Lactobacillus and Acetobacter strains examined displayed good activities against the multidrug-resistant tested pathogens. This is the first report of antimicrobial activities of acetic acid bacteria isolated from yogurt in Nigeria.

  1. Massive production of butanediol during plant infection by phytopathogenic bacteria of the genera Dickeya and Pectobacterium.

    Science.gov (United States)

    Effantin, Géraldine; Rivasseau, Corinne; Gromova, Marina; Bligny, Richard; Hugouvieux-Cotte-Pattat, Nicole

    2011-11-01

    Plant pathogenic bacteria of the genera Dickeya and Pectobacterium are broad-host-range necrotrophs which cause soft-rot diseases in important crops. A metabolomic analysis, based on (13)C-NMR spectroscopy, was used to characterize the plant-bacteria interaction. Metabolic profiles revealed a decline in plant sugars and amino acids during infection and the concomitant appearance of a compound identified as 2,3-butanediol. Butanediol is the major metabolite found in macerated tissues of various host plants. It is accumulated during the symptomatic phase of the disease. Different species of Dickeya or Pectobacterium secrete high levels of butanediol during plant infection. Butanediol has been described as a signalling molecule involved in plant/bacterium interactions and, notably, able to induce plant systemic resistance. The bud genes, involved in butanediol production, are conserved in the phytopathogenic enterobacteria of the genera Dickeya, Pectobacterium, Erwinia, Pantoea and Brenneria. Inactivation of the bud genes of Dickeya dadantii revealed that the virulence of budA, budB and budR mutants was clearly reduced. The genes budA, budB and budC are highly expressed during plant infection. These data highlight the importance of butanediol metabolism in limiting acidification of the plant tissue during the development of the soft-rot disease caused by pectinolytic enterobacteria. © 2011 Blackwell Publishing Ltd.

  2. Capacity of anaerobic bacteria from necrotic dental pulps to induce purulent infections.

    Science.gov (United States)

    Sundqvist, G K; Eckerbom, M I; Larsson, A P; Sjögren, U T

    1979-08-01

    Combinations of bacteria isolated from the root canals of teeth with necrotic pulps and periapical bone destruction were tested for their capacity to induce abscess formation and transmissible infections when inoculated subcutaneously into guinea pigs. Transmissible infections could be induced with combinations obtained from teeth with purulent apical inflammation, but not with combinations from symptomless teeth with chronic apical inflammation. All combinations which gave transmissible infections contained strains of Bacteroides melaninogenicus or B. asaccharolyticus (formerly B. melaninogenicus subsp. asaccharolyticus). The results suggest that purulent inflammation in the apical region in certain cases may be induced by specific combinations of bacteria in the root canal and that the presence of B. melaninogenicus or B. asaccharolyticus in such combinations is essential. However, with one exception, the strains needed the support of additional microorganisms to achieve pathogenicity. The results indicate that Peptostreptococcus micros was also essential. Histological sections of the lesions in the guinea pigs showed that all bacterial combinations induced acute inflammation with an accumulation of polymorphonuclear leukocytes and the formation of an abscess. However, the presence of B. melaninogenicus or B. asaccharolyticus in the combinations resulted in a failure of abscess resolution, with a gradually increaseing accumulation of polymorphonuclear leukocytes.

  3. Gut Microbiota-Induced Immunoglobulin G Controls Systemic Infection by Symbiotic Bacteria and Pathogens

    Science.gov (United States)

    Zeng, Melody Y.; Cisalpino, Daniel; Varadarajan, Saranyaraajan; Hellman, Judith; Warren, H. Shaw; Cascalho, Marilia; Inohara, Naohiro; Núñez, Gabriel

    2016-01-01

    The gut microbiota is compartmentalized in the intestinal lumen and induces local immune responses, but it remains unknown whether the gut microbiota can induce systemic response and contribute to systemic immunity. We report that selective gut symbiotic gram-negative bacteria were able to disseminate systemically to induce immunoglobulin G (IgG) response, which primarily targeted gram-negative bacterial antigens and conferred protection against systemic infections by E. coli and Salmonella by directly coating bacteria to promote killing by phagocytes. T cells and Toll-like receptor 4 on B cells were important in the generation of microbiota-specific IgG. We identified murein lipoprotein (MLP), a highly conserved gram-negative outer membrane protein, as a major antigen that induced systemic IgG homeostatically in both mice and humans. Administration of anti-MLP IgG conferred crucial protection against systemic Salmonella infection. Thus, our findings reveal an important function for the gut microbiota in combating systemic infection through the induction of protective IgG. PMID:26944199

  4. Detection of viruses and atypical bacteria associated with acute respiratory infection of children in Hubei, China.

    Science.gov (United States)

    Wu, Zegang; Li, Yan; Gu, Jian; Zheng, Hongyun; Tong, Yongqing; Wu, Qing

    2014-02-01

    Acute respiratory infection is the major cause of disease and death in children, particularly in developing countries. However, the spectrum of pathogenic viruses and atypical bacteria that exist in many of these countries remains incompletely characterized. The aim of this study was to examine the spectrum of pathogenic viruses and atypical bacteria associated with acute respiratory infection in children under the age of 16. A total of 10 435 serum sera specimens were collected from hospitalized children presenting with acute respiratory infection symptoms. Indirect immunofluorescence assays were performed to detect immunoglobulin M antibodies against nine common pathogens: mycoplasma pneumonia, influenza virus B, respiratory syncytial virus, parainfluenza virus, adenovirus, influenza virus A, legionella pneumophila, coxiella burnetii and chamydophila pneumonia. Of the 10 435 specimens examined, 7046 tested positive for at least one pathogen. Among all of the tested pathogens, mycoplasma pneumonia had the highest detection rate (56.9%). Influenza virus A and influenza virus B epidemics occurred during both winter and summer. The detection rate of respiratory syncytial virus and adenovirus was higher in spring. Cases of mixed infection were more complex: 4136 specimens (39.6%) tested positive for ≥2 pathogens. There were statistically significant difference in detection rates of mycoplasma pneumonia, influenza virus B, respiratory syncytial virus, parainfluenza virus, adenovirus, influenza virus A, legionella pneumophila and chamydophila pneumonia among different age groups (P acute respiratory infection among children in Hubei of China were mycoplasma pneumonia, influenza virus B and respiratory syncytial virus. The detection rates for each pathogen displayed specific seasonal and age group variations. © 2013 The Authors. Respirology © 2013 Asian Pacific Society of Respirology.

  5. Bacteria and viruses modulate FcεRI-dependent mast cell activity 

    Directory of Open Access Journals (Sweden)

    Aleksandra Słodka

    2013-03-01

    Full Text Available Undoubtedly, mast cells play a central role in allergic processes. Specific allergen cross-linking of IgE bound to the high affinity receptors (FcεRI on the mast cell surface leads to the release of preformed mediators and newly synthesized mediators, i.e. metabolites of arachidonic acid and cytokines. More and more data indicate that bacteria and viruses can influence FcεRI-dependent mast cell activation. Some bacterial and viral components can reduce the surface expression of FcεRI. There are also findings that ligation of Toll-like receptors (TLRs by bacterial or viral antigens can affect IgE-dependent mast cell degranulation and preformed mediator release as well as eicosanoid production. The synergistic interaction of TLR ligands and allergen can also modify cytokine synthesis by mast cells stimulated via FcεRI. Moreover, data suggest that specific IgE for bacterial or viral antigens can influence mast cell activity. What is more, some bacterial and viral components or some endogenous proteins produced during viral infection can act as superantigens by interacting with the VH3 domain of IgE. All these observations indicate that bacterial and viral infections modify the course of allergic diseases by affecting FcεRI-dependent mast cell activation. 

  6. Evaluation of the antibacterial potential of Petroselinum crispum and Rosmarinus officinalis against bacteria that cause urinary tract infections

    Directory of Open Access Journals (Sweden)

    Fernanda Villas Boas Petrolini

    2013-09-01

    Full Text Available In this study we evaluated the antibacterial activity of the crude hydroalcoholic extracts, fractions, and compounds of two plant species, namely Rosmarinus officinalis and Petroselinum crispum, against the bacteria that cause urinary tract infection. The microdilution method was used for determination of the minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC. The crude hydroalcoholic extract of R. officinalis displayed in vitro activity against Gram-positive bacteria, with satisfactory MBC for the clinical isolate S. saprophyticus. The fractions and the pure compound rosmarinic acid did not furnish promising results for Gram-negative bacteria, whereas fractions 2, 3, and 4 gave encouraging results for Gram-positive bacteria and acted as bactericide against S. epidermidis as well as E. faecalis (ATCC 29212 and its clinical isolate. R. officinalis led to promising results in the case of Gram-positive bacteria, resulting in a considerable interest in the development of reliable alternatives for the treatment of urinary infections.

  7. Effects of BmCPV Infection on Silkworm Bombyx mori Intestinal Bacteria.

    Directory of Open Access Journals (Sweden)

    Zhenli Sun

    Full Text Available The gut microbiota has a crucial role in the growth, development and environmental adaptation in the host insect. The objective of our work was to investigate the microbiota of the healthy silkworm Bombyx mori gut and changes after the infection of B. mori cypovirus (BmCPV. Intestinal contents of the infected and healthy larvae of B. mori of fifth instar were collected at 24, 72 and 144 h post infection with BmCPV. The gut bacteria were analyzed by pyrosequencing of the 16S rRNA gene. 147(135 and 113(103 genera were found in the gut content of the healthy control female (male larvae and BmCPV-infected female (male larvae, respectively. In general, the microbial communities in the gut content of healthy larvae were dominated by Enterococcus, Delftia, Pelomonas, Ralstonia and Staphylococcus, however the abundance change of each genus was depended on the developmental stage and gender. Microbial diversity reached minimum at 144 h of fifth instar larvae. The abundance of Enterococcus in the females was substantially lower and the abundance of Delftia, Aurantimonas and Staphylococcus was substantially higher compared to the males. Bacterial diversity in the intestinal contents decreased after post infection with BmCPV, whereas the abundance of both Enterococcus and Staphylococcus which belongs to Gram-positive were increased. Therefore, our findings suggested that observed changes in relative abundance was related to the immune response of silkworm to BmCPV infection. Relevance analysis of plenty of the predominant genera showed the abundance of the Enterococcus genus was in negative correlation with the abundance of the most predominant genera. These results provided insight into the relationship between the gut microbiota and development of the BmCPV-infected silkworm.

  8. [Use of antagonistic Bacillus subtilis bacteria for treatment of nosocomial urinary tract infections].

    Science.gov (United States)

    Pushkarev, A M; Tuĭgunova, V G; Zaĭnullin, R R; Kuznetsova, T N; Gabidullin, Iu Z

    2007-01-01

    Effect of Bactisporin--a probiotic, containing spores of aerobic Bacillus subtilis 3H bacterium--for complex treatment of patients with nosocomial urinary tract infections was studied. 68 Cultures of different species of conditionally pathogenic bacteria were isolated from urine of the patients. Susceptibility of the isolated cultures to antibiotics before and after application of B. subtilis 3H metabolites was determined. The metabolites were accumulated on potato-glucose agar (PGA) while bacterium was cultivated on kapron membranes placed on surface of the medium. Influence of obtained metabolites on isolated strains was assessed by cultivation of each strain in metabolites-rich PGA during 24 h. Metabolites of B. subtilis led to decrease in resistance of isolated uropathogenic microflora to antibiotics. Use of Bactisporin in complex treatment of nosocomial urinary tract infections resulted in accelerated elimination of causative microorganism.

  9. Deoxynybomycins inhibit mutant DNA gyrase and rescue mice infected with fluoroquinolone-resistant bacteria.

    Science.gov (United States)

    Parkinson, Elizabeth I; Bair, Joseph S; Nakamura, Bradley A; Lee, Hyang Y; Kuttab, Hani I; Southgate, Emma H; Lezmi, Stéphane; Lau, Gee W; Hergenrother, Paul J

    2015-04-24

    Fluoroquinolones are one of the most commonly prescribed classes of antibiotics, but fluoroquinolone resistance (FQR) is widespread and increasing. Deoxynybomycin (DNM) is a natural-product antibiotic with an unusual mechanism of action, inhibiting the mutant DNA gyrase that confers FQR. Unfortunately, isolation of DNM is difficult and DNM is insoluble in aqueous solutions, making it a poor candidate for development. Here we describe a facile chemical route to produce DNM and its derivatives. These compounds possess excellent activity against FQR methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococci clinical isolates and inhibit mutant DNA gyrase in-vitro. Bacteria that develop resistance to DNM are re-sensitized to fluoroquinolones, suggesting that resistance that emerges to DNM would be treatable. Using a DNM derivative, the first in-vivo efficacy of the nybomycin class is demonstrated in a mouse infection model. Overall, the data presented suggest the promise of DNM derivatives for the treatment of FQR infections.

  10. The transcriptome of HIV-1 infected intestinal CD4+ T cells exposed to enteric bacteria.

    Directory of Open Access Journals (Sweden)

    Alyson C Yoder

    2017-02-01

    Full Text Available Global transcriptome studies can help pinpoint key cellular pathways exploited by viruses to replicate and cause pathogenesis. Previous data showed that laboratory-adapted HIV-1 triggers significant gene expression changes in CD4+ T cell lines and mitogen-activated CD4+ T cells from peripheral blood. However, HIV-1 primarily targets mucosal compartments during acute infection in vivo. Moreover, early HIV-1 infection causes extensive depletion of CD4+ T cells in the gastrointestinal tract that herald persistent inflammation due to the translocation of enteric microbes to the systemic circulation. Here, we profiled the transcriptome of primary intestinal CD4+ T cells infected ex vivo with transmitted/founder (TF HIV-1. Infections were performed in the presence or absence of Prevotella stercorea, a gut microbe enriched in the mucosa of HIV-1-infected individuals that enhanced both TF HIV-1 replication and CD4+ T cell death ex vivo. In the absence of bacteria, HIV-1 triggered a cellular shutdown response involving the downregulation of HIV-1 reactome genes, while perturbing genes linked to OX40, PPAR and FOXO3 signaling. However, in the presence of bacteria, HIV-1 did not perturb these gene sets or pathways. Instead, HIV-1 enhanced granzyme expression and Th17 cell function, inhibited G1/S cell cycle checkpoint genes and triggered downstream cell death pathways in microbe-exposed gut CD4+ T cells. To gain insights on these differential effects, we profiled the gene expression landscape of HIV-1-uninfected gut CD4+ T cells exposed to bacteria. Microbial exposure upregulated genes involved in cellular proliferation, MAPK activation, Th17 cell differentiation and type I interferon signaling. Our findings reveal that microbial exposure influenced how HIV-1 altered the gut CD4+ T cell transcriptome, with potential consequences for HIV-1 susceptibility, cell survival and inflammation. The HIV-1- and microbe-altered pathways unraveled here may serve as a

  11. Giardia co-infection promotes the secretion of antimicrobial peptides beta-defensin 2 and trefoil factor 3 and attenuates attaching and effacing bacteria-induced intestinal disease.

    Science.gov (United States)

    Manko, Anna; Motta, Jean-Paul; Cotton, James A; Feener, Troy; Oyeyemi, Ayodele; Vallance, Bruce A; Wallace, John L; Buret, Andre G

    2017-01-01

    Our understanding of polymicrobial gastrointestinal infections and their effects on host biology remains incompletely understood. Giardia duodenalis is an ubiquitous intestinal protozoan parasite infecting animals and humans. Concomitant infections with Giardia and other gastrointestinal pathogens commonly occur. In countries with poor sanitation, Giardia infection has been associated with decreased incidence of diarrheal disease and fever, and reduced serum inflammatory markers release, via mechanisms that remain obscure. This study analyzed Giardia spp. co-infections with attaching and effacing (A/E) pathogens, and assessed whether and how the presence of Giardia modulates host responses to A/E enteropathogens, and alters intestinal disease outcome. In mice infected with the A/E pathogen Citrobacter rodentium, co-infection with Giardia muris significantly attenuated weight loss, macro- and microscopic signs of colitis, bacterial colonization and translocation, while concurrently enhancing the production and secretion of antimicrobial peptides (AMPs) mouse β-defensin 3 and trefoil factor 3 (TFF3). Co-infection of human intestinal epithelial cells (Caco-2) monolayers with G. duodenalis trophozoites and enteropathogenic Escherichia coli (EPEC) enhanced the production of the AMPs human β-defensin 2 (HBD-2) and TFF3; this effect was inhibited with treatment of G. duodenalis with cysteine protease inhibitors. Collectively, these results suggest that Giardia infections are capable of reducing enteropathogen-induced colitis while increasing production of host AMPs. Additional studies also demonstrated that Giardia was able to directly inhibit the growth of pathogenic bacteria. These results reveal novel mechanisms whereby Giardia may protect against gastrointestinal disease induced by a co-infecting A/E enteropathogen. Our findings shed new light on how microbial-microbial interactions in the gut may protect a host during concomitant infections.

  12. Taurine modulates neutrophil function but potentiates uropathogenic E. coli infection in the murine bladder.

    LENUS (Irish Health Repository)

    Condron, Claire

    2010-08-01

    Eradication of a urinary tract infection (UTI) appears to be related to a number of innate host defence mechanisms and their interactions with invading bacteria. Recurrent UTIs (rUTIs) pose a difficult problem in that these bacteria use both host and bacterial factors to evade elimination. Neutrophil bactericidal function is depressed, both systemically and in urine, in patients with a history of recurrent UTI. Taurine is a semi-essential amino acid and is successful in preserving neutrophil bactericidal function in urine. Taurine may preserve neutrophil function at the urothelium and thus aid UTI resolution. Adult female (6 weeks old) C57Bl\\/6 mice were randomised into three groups: a saline gavage only control group, a saline gavage + E. coli group, and a taurine gavage + E. coli group [21 g\\/70 kg taurine in 0.9% normal saline (N\\/S) for 5 days]. Whilst taurine gavage pre-treatment resulted in increased serum neutrophils respiratory burst activity, at the urothelial-endothelial interface it caused higher colony forming units in the urine and a higher incidence of E. coli invasion in the bladder wall with no evidence of increased bladder wall neutrophils infiltration on MPO assay of histological assessment. Histologically there was also evidence of reduced bladder inflammation and urothelial cell apoptosis. In conclusion, taurine effectively increases neutrophils activity but given its anti-inflammatory properties, at the expense of decreased urothelial-endothelial activation thus preventing clearance of active E. coli infection in the bladder. Despite the negative results, this study demonstrates the importance of modulating interactions at the urothelial interface.

  13. Identifying the major bacteria causing intramammary infections in individual milk samples of sheep and goats using traditional bacteria culturing and real-time polymerase chain reaction.

    Science.gov (United States)

    Rovai, M; Caja, G; Salama, A A K; Jubert, A; Lázaro, B; Lázaro, M; Leitner, G

    2014-09-01

    Use of DNA-based methods, such as real-time PCR, has increased the sensitivity and shortened the time for bacterial identification, compared with traditional bacteriology; however, results should be interpreted carefully because a positive PCR result does not necessarily mean that an infection exists. One hundred eight lactating dairy ewes (56 Manchega and 52 Lacaune) and 24 Murciano-Granadina dairy goats were used for identifying the main bacteria causing intramammary infections (IMI) using traditional bacterial culturing and real-time PCR and their effects on milk performance. Udder-half milk samples were taken for bacterial culturing and somatic cell count (SCC) 3 times throughout lactation. Intramammary infections were assessed based on bacteria isolated in ≥2 samplings accompanied by increased SCC. Prevalence of subclinical IMI was 42.9% in Manchega and 50.0% in Lacaune ewes and 41.7% in goats, with the estimated milk yield loss being 13.1, 17.9, and 18.0%, respectively. According to bacteriology results, 87% of the identified single bacteria species (with more than 3 colonies/plate) or culture-negative growth were identical throughout samplings, which agreed 98.9% with the PCR results. Nevertheless, the study emphasized that 1 sampling may not be sufficient to determine IMI and, therefore, other inflammatory responses such as increased SCC should be monitored to identify true infections. Moreover, when PCR methodology is used, aseptic and precise milk sampling procedures are key for avoiding false-positive amplifications. In conclusion, both PCR and bacterial culture methods proved to have similar accuracy for identifying infective bacteria in sheep and goats. The final choice will depend on their response time and cost analysis, according to the requirements and farm management strategy. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  14. Early immune response patterns to pathogenic bacteria are associated to increased risk of lower respiratory infections in children

    DEFF Research Database (Denmark)

    Vissing, N. H.; Larsen, Jeppe Madura; Rasmussen, Mette Annelie

    2014-01-01

    Neonatal colonisation of the airways with respiratory pathogens is associated with increased risk of lower respiratory infections (LRI) in early childhood (1). Therefore, we hypothesized that children developing LRI have an abnormal immune response to pathogenic bacteria in infancy. We aimed...... to characterise the systemic immune response to pathogenic bacteria at the age of 6 months and study the association with incidence of LRI during the first 3 years of life....

  15. [Respiratory infections caused by slow-growing bacteria: Nocardia, Actinomyces, Rhodococcus].

    Science.gov (United States)

    Eschapasse, E; Hussenet, C; Bergeron, A; Lebeaux, D

    2017-06-01

    Pneumonia caused by slow-growing bacteria is rare but sometimes severe. These infections share many similarities such as several differential diagnoses, difficulties to identify the pathogen, the importance of involving the microbiologist in the diagnostic investigation and the need for prolonged antibiotic treatment. However, major differences distinguish them: Nocardia and Rhodococcus infect mainly immunocompromised patients while actinomycosis also concerns immunocompetent patients; the severity of nocardioses is related to their hematogenous spread while locoregional extension by contiguity makes the gravity of actinomycosis. For these diseases, molecular diagnostic tools are essential, either to obtain a species identification and guide treatment in the case of nocardiosis or to confirm the diagnosis from a biological sample. Treatment of these infections is complex due to: (1) the limited data in the literature; (2) the need for prolonged treatment of several months; (3) the management of toxicities and drug interactions for the treatment of Nocardia and Rhodococcus. Close cooperation between pneumonologists, infectious disease specialists and microbiologists is essential for the management of these patients. Copyright © 2017 SPLF. Published by Elsevier Masson SAS. All rights reserved.

  16. Antibiotic sensitivity pattern of bacteria from diabetic foot infections Haji Adam Malik central general hospital

    Science.gov (United States)

    Bulolo, B. A.; Pase, M. A.; Ginting, F.

    2018-03-01

    Increasing rate of Diabetic Foot Infections (DFIs) caused by multi-drug-resistance pathogens plays a huge role in the duration of hospitalization, morbidity, and mortality of diabetic patients. The aim of the study is to assess the antibiotic sensitivity pattern of bacteria in DFIs and causative microorganisms. Using cross-sectional retrospective study, data were collected from medical records of DFIs patients previously hospitalized atHaji Adam Malik Hospital, Medan from January to July 2017. 33 patients met the criteria and got enrolled in the study. The classification of DFIs was evaluated according to Wagner’s Classification. Evaluation of antibiotic sensitivity and identification of causative microorganisms were performed in standard microbiologic methods. The most common grade of DFIs was Grade-4 (48.5%), followed by Grade-3 (39.4%) and Grade-5 (9.1%). A total of 12 pathogens were identified. The most common infecting microorganism isolated on pus cultures was Klebsiella pneumonia (33.3%), followed by Escherichia coli (24.2%), Acinetobacter baumanni (12.1%), and Staphylococcus aureus (9.1%). Frequent susceptible antibiotics were Amikacin (88.8%), Imipenem (87%), Meropenem (84.6%), Erythromycin (75%), and Cefoperazone/Sulbactam (68.9%). DFIs are polymicrobial infections in this study K. pneumonia was the most common cause microorganism.

  17. Complicated urinary tract infections: practical solutions for the treatment of multiresistant Gram-negative bacteria.

    Science.gov (United States)

    Pallett, Ann; Hand, Kieran

    2010-11-01

    Resistance in Gram-negative bacteria has been increasing, particularly over the last 6 years. This is mainly due to the spread of strains producing extended-spectrum β-lactamases (ESBLs) such as CTX-M enzymes or AmpC β-lactamases. Many of the isolates producing these enzymes are also resistant to trimethoprim, quinolones and aminoglycosides, often due to plasmid co-expression of other resistance mechanisms. CTX-M-producing Escherichia coli often occurs in the community and as E. coli is one of the commonest organisms causing urinary tract infections (UTIs) the choice of agents to treat these infections is diminishing. Novel combinations of antibiotics are being used in the community and broad-spectrum agents such as carbapenems are being used increasingly as empirical treatment for severe infections. Of particular concern therefore are reports in the UK of organisms that produce carbapenemases. As resistance is becoming more widespread, prudent use of antimicrobials is imperative and, as asymptomatic bacteriuria is typically benign in the elderly, antibiotics should not be prescribed without clinical signs of UTI. The use of antibiotics as suppressive therapy or long-term prophylaxis may no longer be defensible.

  18. Quantification of Propionic Acid in the Bovine Spinal Disk After Infection of the Tissue With Propionibacteria acnes Bacteria.

    Science.gov (United States)

    Magnitsky, Sergey; Dudli, Stefan; Tang, Xinyan; Kaur, Jaskanwaljeet; Diaz, Joycelyn; Miller, Steve; Lotz, Jeffrey C

    2018-06-01

    Research. The goal of this study was to investigate whether Propionibacteria acnes infection of the intervertebral disc can be detected noninvasively by nuclear magnetic resonance (NMR) spectroscopy. Microbiological studies of surgical samples suggest that a significant subpopulation of back pain patients may have occult disc infection with P. acnes bacteria. This hypothesis is further supported by a double-blind clinical trial showing that back pain patients with Modic type 1 changes may respond to antibiotic treatment. Because significant side effects are associated with antibiotic treatment, there is a need for a noninvasive method to detect whether specific discs in back pain patients are infected with P acnes bacteria. P. acnes bacteria were obtained from human patients. NMR detection of a propionic acid (PA) in the bacteria extracts was conducted on 500 MHz high-resolution spectrometer, whereas in vivo NMR spectroscopy of an isolated bovine disk tissue infected with P. acnes was conducted on 7 T magnetic resonance imaging scanner. NMR spectra of P. acnes metabolites revealed a distinct NMR signal with identical chemical shits (1.05 and 2.18 ppm) as PA (a primary P. acne metabolite). The 1.05 ppm signal does not overlap with other bacteria metabolites, and its intensity increases linearly with P. acnes concentration. Bovine disks injected with P. acnes bacteria revealed a very distinct NMR signal at 1.05 ppm, which linearly increased with P. acnes concentration. The 1.05 ppm NMR signal from PA can be used as a marker of P. acnes infection of discs. This signal does not overlap with other disc metabolites and linearly depends on P. acnes concentration. Consequently, NMR spectroscopy may provide a noninvasive method to detect disc infection in the clinical setting. N/A.

  19. Effect of respiratory syncytial virus (RSV) infection on the adherence of pathogenic bacteria to human epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Faden, H.; Hong, J.J.; Ogra, P.L.

    1986-03-01

    The effect of RSV infection on the adherence of Streptococcus pneumoniae (SP), Haemophilus influenzae (HI) and Staphylococcus aureus (SA) to human epithelial cells was determined. RSV-infected Hep-2 cell cultures at different stages of expression of surface viral antigens and bacteria labeled with /sup 3/H-thymidine were employed to examine the kinetics of bacterial adherence to virus-infected cells. RSV infection did not alter the magnitude of adherence of HI or SA to HEp-2 cells. However, adherence of SP to HEp-2 cells was significantly (P < 0.01) enhanced by prior RSV infection. The degree of adherence was directly related to the amount of viral antigen expressed on the cell surface. The adherence was temperature dependent, with maximal adherence observed at 37/sup 0/C. Heat-inactivation of SP did not alter adherence characteristics. These data suggest that RSV infection increases adherence of SP to the surface of epithelial cells in vitro. Since attachment of bacteria to mucosal surfaces is the first step in many infections, it is suggested that viral infections of epithelial cells render them more susceptible to bacterial adherence. Thus, RSV infection in vivo may predispose children to SP infections, such as in otitis media, by increasing colonization with SP.

  20. 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.

  1. Bacteriophages to combat foodborne infections caused by food contamination by bacteria of the Campylobacter genus

    Directory of Open Access Journals (Sweden)

    Magdalena Myga-Nowak

    2016-09-01

    Full Text Available It is estimated that each year more than 2 million people suffer from diarrheal diseases, resulting from the consumption of contaminated meat. Foodborne infections are most frequently caused by small Gram-negative rods Campylobacter. The hosts of these bacteria are mainly birds wherein they are part of the normal intestinal flora. During the commercial slaughter, there is a likelihood of contamination of carcasses by the bacteria found in the intestinal content. In Europe, up to 90% of poultry flocks can be a reservoir of the pathogen. According to the European Food Safety Authority report from 2015, the number of reported and confirmed cases of human campylobacteriosis exceeds 200 thousands per year, and such trend remains at constant level for several years. The occurrence of growing antibiotic resistance in bacteria forces the limitation of antibiotic use in the animal production. Therefore, the European Union allows only using stringent preventive and hygienic treatment on farms. Achieving Campylobacter free chickens using these methods is possible, but difficult to implement and expensive. Utilization of bacterial viruses – bacteriophages, can be a path to provide the hygienic conditions of poultry production and food processing. Formulations applied in the food protection should contain strictly lytic bacteriophages, be non-pyrogenic and retain long lasting biological activity. Currently, on the market there are available commercial bacteriophage preparations for agricultural use, but neither includes phages against Campylobacter. However, papers on the application of bacteriophages against Campylobacter in chickens and poultry products were published in the last few years. In accordance with the estimates, 2-logarithm reduction of Campylobacter in poultry carcases will contribute to the 30-fold reduction in the incidence of campylobacteriosis in humans. Research on bacteriophages against Campylobacter have cognitive and economic

  2. Susceptibility of bacteria isolated from acute gastrointestinal infections to rifaximin and other antimicrobial agents in Mexico.

    Science.gov (United States)

    Novoa-Farías, O; Frati-Munari, A C; Peredo, M A; Flores-Juárez, S; Novoa-García, O; Galicia-Tapia, J; Romero-Carpio, C E

    2016-01-01

    Bacterial resistance may hamper the antimicrobial management of acute gastroenteritis. Bacterial susceptibility to rifaximin, an antibiotic that achieves high fecal concentrations (up to 8,000μg/g), has not been evaluated in Mexico. To determine the susceptibility to rifaximin and other antimicrobial agents of enteropathogenic bacteria isolated from patients with acute gastroenteritis in Mexico. Bacterial strains were analyzed in stool samples from 1,000 patients with diagnosis of acute gastroenteritis. The susceptibility to rifaximin (RIF) was tested by microdilution (<100, <200, <400 and <800μg/ml) and susceptibility to chloramphenicol (CHL), trimethoprim-sulfamethoxazole (T-S), neomycin (NEO), furazolidone (FUR), fosfomycin (FOS), ampicillin (AMP) and ciprofloxacin (CIP) was tested by agar diffusion at the concentrations recommended by the Clinical & Laboratory Standards Institute and the American Society for Microbiology. Isolated bacteria were: enteropathogenic Escherichia coli (E. coli) (EPEC) 531, Shigella 120, non-Typhi Salmonella 117, Aeromonas spp. 80, enterotoxigenic E. coli (ETEC) 54, Yersinia enterocolitica 20, Campylobacter jejuni 20, Vibrio spp. 20, Plesiomonas shigelloides 20, and enterohemorrhagic E. coli (EHEC 0:157) 18. The overall cumulative susceptibility to RIF at <100, <200, <400, and <800μg/ml was 70.6, 90.8, 99.3, and 100%, respectively. The overall susceptibility to each antibiotic was: AMP 32.2%, T-S 53.6%, NEO 54.1%, FUR 64.7%, CIP 67.3%, CLO 73%, and FOS 81.3%. The susceptibility to RIF <400 and RIF <800μg/ml was significantly greater than with the other antibiotics (p<0.001). Resistance of enteropathogenic bacteria to various antibiotics used in gastrointestinal infections is high. Rifaximin was active against 99-100% of these enteropathogens at reachable concentrations in the intestine with the recommended dose. Copyright © 2015 Asociación Mexicana de Gastroenterología. Published by Masson Doyma México S.A. All rights reserved.

  3. Outcome of Transplantation Using Organs From Donors Infected or Colonized With Carbapenem-Resistant Gram-Negative Bacteria.

    Science.gov (United States)

    Mularoni, A; Bertani, A; Vizzini, G; Gona, F; Campanella, M; Spada, M; Gruttadauria, S; Vitulo, P; Conaldi, P; Luca, A; Gridelli, B; Grossi, P

    2015-10-01

    Donor-derived infections due to multidrug-resistant bacteria are a growing problem in solid organ transplantation, and optimal management options are not clear. In a 2-year period, 30/214 (14%) recipients received an organ from 18/170 (10.5%) deceased donors with infection or colonization caused by a carbapenem-resistant gram-negative bacteria that was unknown at the time of transplantation. Among them, 14/30 recipients (47%) received a transplant from a donor with bacteremia or with infection/colonization of the transplanted organ and were considered at high risk of donor-derived infection transmission. The remaining 16/30 (53%) recipients received an organ from a nonbacteremic donor with colonization of a nontransplanted organ and were considered at low risk of infection transmission. Proven transmission occurred in 4 of the 14 high-risk recipients because donor infection was either not recognized, underestimated, or not communicated. These recipients received late, short or inappropriate posttransplant antibiotic therapy. Transmission did not occur in high-risk recipients who received appropriate and prompt antibiotic therapy for at least 7 days. The safe use of organs from donors with multidrug-resistant bacteria requires intra- and inter-institutional communication to allow appropriate management and prompt treatment of recipients in order to avoid transmission of infection. © Copyright 2015 The American Society of Transplantation and the American Society of Transplant Surgeons.

  4. [Effect of compound Chinese traditional medicine on infected root canal bacteria biofilm].

    Science.gov (United States)

    Ma, Rui; Huang, Li-li; Xia, Wen-wei; Zhu, Cai-lian; Ye, Dong-xia

    2010-08-01

    To assess the efficacy of compound Chinese traditional medicine(CTM), which composed of gallic acid, magnolol and polysaccharide of Blettila striata, against the infected root canal bacterial biofilm. Actinomyces viscosus (Av), Enterococcus faecalis (Ef), Fusobacterium nucleatum (Fn) were composed to form biofilm, then confocal laser scan microscope (CLSM) was used to observe and study the bacterial activity. SAS6.12 software package was used for statistical analysis. The biofilm thickness reduced after treatment by both CTM and ZnO (P>0.05),while there was a significant decrease of the percentage of vital bacterias after treatment by CTM (Pcompound Chinese traditional medicine is effective on biofilm control, so that it would be an effective disinfecting drug for root canal sealers. Supported by Research Fund of Bureau of Traditional Chinese Medicine of Shanghai Municipality (Grant No.2008L008A).

  5. 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

  6. Etiological and Resistance Profile of Bacteria Involved in Urinary Tract Infections in Young Children

    Directory of Open Access Journals (Sweden)

    Antonio Sorlózano-Puerto

    2017-01-01

    Full Text Available Background. The objective of this study was to identify the bacteria most frequently responsible for urinary tract infection (UTI in the population of under-2-year-olds in our geographic area and to evaluate the activity of antibiotics widely used for UTI treatment during a 4-year study period. Materials and Methods. A retrospective analysis was conducted of data on the identification and susceptibility of microorganisms isolated in urine samples from children under 2 years of age. Results. A total of 1,045 uropathogens were isolated. Escherichia coli accounted for the majority (60.3% of these, followed by Enterococcus faecalis (22.4% and Klebsiella spp. (6.5%. The highest E. coli susceptibility rates (>90% were to piperacillin-tazobactam, cefuroxime, cefotaxime, ceftazidime, imipenem, gentamicin, nitrofurantoin, and fosfomycin, and the lowest were to amoxicillin-clavulanic acid and cotrimoxazole. Among all bacteria isolated, we highlight the overall high activity of piperacillin-tazobactam, imipenem, nitrofurantoin, and fosfomycin against both community and hospital isolates and the reduced activity of amoxicillin-clavulanic acid, cephalosporins, gentamicin, and cotrimoxazole. There was no significant change in the total activity of any of the studied antibiotics over the 4-year study period. Conclusion. Empiric treatment with amoxicillin-clavulanic acid, cotrimoxazole, cephalosporins, and gentamicin may be inadequate due to their limited activity against uropathogens in our setting.

  7. Granuloma Annulare and Morphea: Correlation with Borrelia burgdorferi Infections and Chlamydia-related Bacteria

    Directory of Open Access Journals (Sweden)

    Lauri Tolkki

    2017-12-01

    Full Text Available A retrospective study of 109 skin biopsies with granuloma annulare (GA or morphea histology from patients with suspected tick bite was performed. Biopsies were tested for cutaneous Borrelia burgdorferi DNA using PCR. The same biopsies were analysed for tick-borne novel agents, Chlamydia-related bacteria (members of the Chlamydiales order, using a PCR-based method. Borrelia DNA was detected in 7/73 (9.6% biopsies with GA and in 1/36 (2.8 % biopsies with morphea, while Chlamydiales DNA was found in 53/73 (72.6% biopsies with GA and 25/34 (73.4% biopsies with morphea. All Borrelia DNA-positive GA samples were also positive for Chlamydiales DNA. The Chlamydiales sequences detected in GA were heterogeneous and contained Waddliaceae and Rhabdochlamydiaceae bacteria, which are also present in Ixodes ricinus ticks, while the Chlamydiales sequences detected in morphea closely resembled those found in healthy skin. In conclusion, tick-mediated infections can trigger GA in some cases, while correlation of either Borrelia or Chlamydiales with morphea is unlikely.

  8. Effect of respiratory syncytial virus (RSV) infection on the adherence of pathogenic bacteria to human epithelial cells

    International Nuclear Information System (INIS)

    Faden, H.; Hong, J.J.; Ogra, P.L.

    1986-01-01

    The effect of RSV infection on the adherence of Streptococcus pneumoniae (SP), Haemophilus influenzae (HI) and Staphylococcus aureus (SA) to human epithelial cells was determined. RSV-infected Hep-2 cell cultures at different stages of expression of surface viral antigens and bacteria labeled with 3 H-thymidine were employed to examine the kinetics of bacterial adherence to virus-infected cells. RSV infection did not alter the magnitude of adherence of HI or SA to HEp-2 cells. However, adherence of SP to HEp-2 cells was significantly (P 0 C. Heat-inactivation of SP did not alter adherence characteristics. These data suggest that RSV infection increases adherence of SP to the surface of epithelial cells in vitro. Since attachment of bacteria to mucosal surfaces is the first step in many infections, it is suggested that viral infections of epithelial cells render them more susceptible to bacterial adherence. Thus, RSV infection in vivo may predispose children to SP infections, such as in otitis media, by increasing colonization with SP

  9. Infection Status of Hospitalized Diarrheal Patients with Gastrointestinal Protozoa, Bacteria, and Viruses in the Republic of Korea

    Science.gov (United States)

    Cho, Shin-Hyeong; Lee, Jin-Hee; Lim, Yi-Young; Jeon, Ji-Hye; Yu, Jae-Ran; Kim, Tong-Soo; Lee, Won-Ja; Cho, Seung-Hak; Lee, Deog-Yong; Park, Mi-Seon; Jeong, Hye-Sook; Chen, Doo-Sung; Ji, Yeong-Mi; Kwon, Mi-Hwa

    2010-01-01

    To understand protozoan, viral, and bacterial infections in diarrheal patients, we analyzed positivity and mixed-infection status with 3 protozoans, 4 viruses, and 10 bacteria in hospitalized diarrheal patients during 2004-2006 in the Republic of Korea. A total of 76,652 stool samples were collected from 96 hospitals across the nation. The positivity for protozoa, viruses, and bacteria was 129, 1,759, and 1,797 per 10,000 persons, respectively. Especially, Cryptosporidium parvum was highly mixed-infected with rotavirus among pediatric diarrheal patients (29.5 per 100 C. parvum positive cases), and Entamoeba histolytica was mixed-infected with Clostridium perfringens (10.3 per 100 E. histolytica positive cases) in protozoan-diarrheal patients. Those infected with rotavirus and C. perfringens constituted relatively high proportions among mixed infection cases from January to April. The positivity for rotavirus among viral infection for those aged ≤ 5 years was significantly higher, while C. perfringens among bacterial infection was higher for ≥ 50 years. The information for association of viral and bacterial infections with enteropathogenic protozoa in diarrheal patients may contribute to improvement of care for diarrhea as well as development of control strategies for diarrheal diseases in Korea. PMID:20585526

  10. Screening and contact precautions – A survey on infection control measures for multidrug-resistant bacteria in German university hospitals

    Directory of Open Access Journals (Sweden)

    Lena M. Biehl

    2017-04-01

    Full Text Available Abstract To assess the scope of infection control measures for multidrug-resistant bacteria in high-risk settings, a survey among university hospitals was conducted. Fourteen professionals from 8 sites participated. Reported policies varied largely with respect to the types of wards conducting screening, sample types used for screening and implementation of contact precautions. This variability among sites highlights the need for an evidence-based consensus of current infection control policies.

  11. Cereal fungal infection, mycotoxins, and lactic acid bacteria mediated bioprotection: from crop farming to cereal products.

    Science.gov (United States)

    Oliveira, Pedro M; Zannini, Emanuele; Arendt, Elke K

    2014-02-01

    Lactic acid bacteria (LAB) metabolites are a reliable alternative for reducing fungal infections pre-/post-harvest with additional advantages for cereal-base products which convene the food market's trend. Grain industrial use is in expansion owing to its applicability in generating functional food. The food market is directed towards functional natural food with clear health benefits for the consumer in detriment to chemical additives. The food market chain is becoming broader and more complex, which presents an ever-growing fungal threat. Toxigenic and spoilage fungi are responsible for numerous diseases and economic losses. Cereal infections may occur in the field or post-processing, along the food chain. Consequently, the investigation of LAB metabolites with antifungal activity has gained prominence in the scientific research community. LAB bioprotection retards the development of fungal diseases in the field and inhibit pathogens and spoilage fungi in food products. In addition to the health safety improvement, LAB metabolites also enhance shelf-life, organoleptic and texture qualities of cereal-base foods. This review presents an overview of the fungal impact through the cereal food chain leading to investigation on LAB antifungal compounds. Applicability of LAB in plant protection and cereal industry is discussed. Specific case studies include Fusarium head blight, malting and baking. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Synergistic interaction of Helichrysum pedunculatum leaf extracts with antibiotics against wound infection associated bacteria

    Directory of Open Access Journals (Sweden)

    OLAYINKA A AIYEGORO

    2009-01-01

    Full Text Available The effect of combinations of the crude methanolic extract of the leaves of Helichrysum pedunculatum and eight first-line antibiotics were investigated by time kill assays against a panel of bacterial strains that have been implicated in wound infections. The plant extract showed appreciable antibacterial activities against the test bacteria with zones of inhibition ranging between 18 and 27 mm, and minimum inhibitory concentrations (MICs varying between 0.1 and 5.0 mg/ml. The MICs of the test antibiotics range between 0.001 and 0.412 mg/ml, and combination of the plant extract and the antibiotics resulted in reduction of bacterial counts by between 0 and 6.63 Log10 cfu/ml. At V2 MIC, 56.81% synergy; 43.19% indifference and no antagonism were observed, and at MIC levels, 55.68% synergy; 44.32% indifference and no antagonism were observed when the extracts were combined with eight different antibiotics. In all, 60% of the interactions were synergistic. All combination regimes on Staphylococcus aureus ATCC 6538 yielded no synergy, neither was antagonism detected in any of the assays. We propose that extracts of the leaves of Helichrysum pedunculatum could be of relevance in combination therapy and as a source of resistance modifying principies that could be useful as treatment options for persistent wound infections.

  13. Synergistic interaction of Helichrysum pedunculatum leaf extracts with antibiotics against wound infection associated bacteria.

    Science.gov (United States)

    Aiyegoro, Olayinka A; Afolayan, Anthony J; Okoh, Anthony I

    2009-01-01

    The effect of combinations of the crude methanolic extract of the leaves of Helichrysum pedunculatum and eight first-line antibiotics were investigated by time kill assays against a panel of bacterial strains that have been implicated in wound infections. The plant extract showed appreciable antibacterial activities against the test bacteria with zones of inhibition ranging between 18 and 27 mm, and minimum inhibitory concentrations (MICs) varying between 0.1 and 5.0 mg/ml. The MICs of the test antibiotics range between 0.001 and 0.412 mg/ml, and combination of the plant extract and the antibiotics resulted in reduction of bacterial counts by between 0 and 6.63 Log10 cfu/ml. At V2 MIC, 56.81% synergy; 43.19% indifference and no antagonism were observed, and at MIC levels, 55.68% synergy; 44.32% indifference and no antagonism were observed when the extracts were combined with eight different antibiotics. In all, 60% of the interactions were synergistic. All combination regimes on Staphylococcus aureus ATCC 6538 yielded no synergy, neither was antagonism detected in any of the assays. We propose that extracts of the leaves of Helichrysum pedunculatum could be of relevance in combination therapy and as a source of resistance modifying principies that could be useful as treatment options for persistent wound infections.

  14. Effect of Probiotic Bacteria on Microbial Host Defense, Growth, and Immune Function in Human Immunodeficiency Virus Type-1 Infection

    Directory of Open Access Journals (Sweden)

    Stig Bengmark

    2011-12-01

    Full Text Available The hypothesis that probiotic administration protects the gut surface and could delay progression of Human Immunodeficiency Virus type1 (HIV-1 infection to the Acquired Immunodeficiency Syndrome (AIDS was proposed in 1995. Over the last five years, new studies have clarified the significance of HIV-1 infection of the gut associated lymphoid tissue (GALT for subsequent alterations in the microflora and breakdown of the gut mucosal barrier leading to pathogenesis and development of AIDS. Current studies show that loss of gut CD4+ Th17 cells, which differentiate in response to normal microflora, occurs early in HIV-1 disease. Microbial translocation and suppression of the T regulatory (Treg cell response is associated with chronic immune activation and inflammation. Combinations of probiotic bacteria which upregulate Treg activation have shown promise in suppressing pro inflammatory immune response in models of autoimmunity including inflammatory bowel disease and provide a rationale for use of probiotics in HIV-1/AIDS. Disturbance of the microbiota early in HIV-1 infection leads to greater dominance of potential pathogens, reducing levels of bifidobacteria and lactobacillus species and increasing mucosal inflammation. The interaction of chronic or recurrent infections, and immune activation contributes to nutritional deficiencies that have lasting consequences especially in the HIV-1 infected child. While effective anti-retroviral therapy (ART has enhanced survival, wasting is still an independent predictor of survival and a major presenting symptom. Congenital exposure to HIV-1 is a risk factor for growth delay in both infected and non-infected infants. Nutritional intervention after 6 months of age appears to be largely ineffective. A meta analysis of randomized, controlled clinical trials of infant formulae supplemented with Bifidobacterium lactis showed that weight gain was significantly greater in infants who received B. lactis compared to

  15. The Antibacterial Effect of Methanolic and Aqueous Extracts of Stachys schtschegleevii (Poulk Leave on Bacteria Causing Urinary Infection

    Directory of Open Access Journals (Sweden)

    Atefe Bayat

    2015-12-01

    Full Text Available Background and Objectives: The medical herb Poulk is used for the treatment of infectious diseases in urinary tract, vagina, respiratory tract, rheumatism, ear infections, and other inflammatory conditions. In this study, the antibacterial effect of methanolic and aqueous extracts of Poulk on bacterial infection of urine, was investigated. Methods: In this experimental study, techniques for determining minimum inhibitory concentration (MIC of bacterial growth, minimum bactericidal concentration (MBC, and disk diffusion were used to investigate the antibacterial effects of Poulk on the mentioned bacteria. Data were analyzed using analysis of variance and Duncan’s tests. Significance level was considered p<0.05. Results: In this study, Staphylococcus aureus, Klebsiella pneumoniae, and Enterobacter aerogenes bacteria showed sensitivity to aqueous and methanolic extracts of Poulk in different concentrations. Proteus mirabilis bacteria with an inhibition zone diameter of (2.00±0.2 mm was the most resistant and Staphylococcus aureus bacteria with an inhibition zone diameter of (20.50±0.2mm was the most sensitive bacteria to the extract effect. The effect of methanolic and aqueous extracts on staphylococcus aureus was the same. Hydro-methanolic extracts showed MIC and MBC, but aqueous extracts had no bactericidal effect on the bacteria. Conclusion: The findings of this research indicate that aqueous and methanolic extracts of poulk have strong antibacterial effects                on Enterobacter aerogenes and Klebsiella pneumoniae, and Staphylococcus aureus (bacteria causing urinary infections, but no effect on Proteus mirabilis.

  16. Host AMPK Is a Modulator of Plasmodium Liver Infection

    Directory of Open Access Journals (Sweden)

    Margarida T. Grilo Ruivo

    2016-09-01

    Full Text Available Manipulation of the master regulator of energy homeostasis AMP-activated protein kinase (AMPK activity is a strategy used by many intracellular pathogens for successful replication. Infection by most pathogens leads to an activation of host AMPK activity due to the energetic demands placed on the infected cell. Here, we demonstrate that the opposite is observed in cells infected with rodent malaria parasites. Indeed, AMPK activity upon the infection of hepatic cells is suppressed and dispensable for successful infection. By contrast, an overactive AMPK is deleterious to intracellular growth and replication of different Plasmodium spp., including the human malaria parasite, P. falciparum. The negative impact of host AMPK activity on infection was further confirmed in mice under conditions that activate its function. Overall, this work establishes the role of host AMPK signaling as a suppressive pathway of Plasmodium hepatic infection and as a potential target for host-based antimalarial interventions.

  17. Modulation of cell surface hydrophobicity and attachment of bacteria to abiotic surfaces and shrimp by Malaysian herb extracts.

    Science.gov (United States)

    Hui, Yew Woh; Dykes, Gary A

    2012-08-01

    The use of simple crude water extracts of common herbs to reduce bacterial attachment may be a cost-effective way to control bacterial foodborne pathogens, particularly in developing countries. The ability of water extracts of three common Malaysian herbs (Andrographis paniculata, Eurycoma longifolia, and Garcinia atroviridis) to modulate hydrophobicity and attachment to surfaces of five food-related bacterial strains (Bacillus cereus ATCC 14576, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 10145, Salmonella Enteritidis ATCC 13076, Staphylococcus aureus ATCC 25923) were determined. The bacterial attachment to hydrocarbon assay was used to determine bacterial hydrophobicity. Staining and direct microscopic counts were used to determine attachment of bacteria to glass and stainless steel. Plating on selective media was used to determine attachment of bacteria to shrimp. All extracts were capable of either significantly ( P 0.05) to bacterial attachment. For specific combinations of bacteria, surface material, and plant extract, significant correlations (R > 0.80) between hydrophobicity and attachment were observed. The highest of these was observed for S. aureus attachment to stainless steel and glass after treatment with the E. longifolia extract (R = 0.99, P < 0.01). The crude water herb extracts in this study were shown to have the potential to modulate specific bacterial and surface interactions and may, with further work, be useful for the simple and practical control of foodborne pathogens.

  18. Effect of antibiotic stewardship on the incidence of infection and colonisation with antibiotic-resistant bacteria and Clostridium difficile infection: a systematic review and meta-analysis.

    Science.gov (United States)

    Baur, David; Gladstone, Beryl Primrose; Burkert, Francesco; Carrara, Elena; Foschi, Federico; Döbele, Stefanie; Tacconelli, Evelina

    2017-09-01

    Antibiotic stewardship programmes have been shown to reduce antibiotic use and hospital costs. We aimed to evaluate evidence of the effect of antibiotic stewardship on the incidence of infections and colonisation with antibiotic-resistant bacteria. For this systematic review and meta-analysis, we searched PubMed, the Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, and Web of Science for studies published from Jan 1, 1960, to May 31, 2016, that analysed the effect of antibiotic stewardship programmes on the incidence of infection and colonisation with antibiotic-resistant bacteria and Clostridium difficile infections in hospital inpatients. Two authors independently assessed the eligibility of trials and extracted data. Studies involving long-term care facilities were excluded. The main outcomes were incidence ratios (IRs) of target infections and colonisation per 1000 patient-days before and after implementation of antibiotic stewardship. Meta-analyses were done with random-effect models and heterogeneity was calculated with the I 2 method. We included 32 studies in the meta-analysis, comprising 9 056 241 patient-days and 159 estimates of IRs. Antibiotic stewardship programmes reduced the incidence of infections and colonisation with multidrug-resistant Gram-negative bacteria (51% reduction; IR 0·49, 95% CI 0·35-0·68; pdifficile infections (32%; 0·68, 0·53-0·88; p=0·0029). Antibiotic stewardship programmes were more effective when implemented with infection control measures (IR 0·69, 0·54-0·88; p=0·0030), especially hand-hygiene interventions (0·34, 0·21-0·54; pinfections and colonisation with antibiotic-resistant bacteria and C difficile infections in hospital inpatients. These results provide stakeholders and policy makers with evidence for implementation of antibiotic stewardship interventions to reduce the burden of infections from antibiotic-resistant bacteria. German Center for Infection Research

  19. Clinical identification of bacteria in human chronic wound infections: culturing vs. 16S ribosomal DNA sequencing

    Directory of Open Access Journals (Sweden)

    Rhoads Daniel D

    2012-11-01

    Full Text Available Abstract Background Chronic wounds affect millions of people and cost billions of dollars in the United States each year. These wounds harbor polymicrobial biofilm communities, which can be difficult to elucidate using culturing methods. Clinical molecular microbiological methods are increasingly being employed to investigate the microbiota of chronic infections, including wounds, as part of standard patient care. However, molecular testing is more sensitive than culturing, which results in markedly different results being reported to clinicians. This study compares the results of aerobic culturing and molecular testing (culture-free 16S ribosomal DNA sequencing, and it examines the relative abundance score that is generated by the molecular test and the usefulness of the relative abundance score in predicting the likelihood that the same organism would be detected by culture. Methods Parallel samples from 51 chronic wounds were studied using aerobic culturing and 16S DNA sequencing for the identification of bacteria. Results One hundred forty-five (145 unique genera were identified using molecular methods, and 68 of these genera were aerotolerant. Fourteen (14 unique genera were identified using aerobic culture methods. One-third (31/92 of the cultures were determined to be Staphylococcus aureus, Pseudomonas aeruginosa, and Enterococcus faecalis with higher relative abundance scores were more likely to be detected by culture as demonstrated with regression modeling. Conclusion Discordance between molecular and culture testing is often observed. However, culture-free 16S ribosomal DNA sequencing and its relative abundance score can provide clinicians with insight into which bacteria are most abundant in a sample and which are most likely to be detected by culture.

  20. Relevance of biofilm bacteria in modulating the larval metamorphosis of Balanus amphitrite

    Digital Repository Service at National Institute of Oceanography (India)

    Khandeparker, L.; Anil, A.C.; Raghukumar, S.

    Balanus amphitrite, on its larval metamorphosis. The effect of multispecies bacterial film was also assessed. The production of different molecules by the bacteria was influenced by the nutrient media under which they were grown. It was observed...

  1. Surgical site infection in orthopedic implants and its common bacteria with their sensitivities to antibiotics, in open reduction internal fixation

    International Nuclear Information System (INIS)

    Shah, M.Q.; Zardad, M.S.; Khan, A.; Ahmed, S.; Awan, A. S.; Mohammad, T.

    2017-01-01

    Surgical site infection in orthopaedic implants is a major problem, causing long hospital stay, cost to the patient and is a burden on health care facilities. It increases rate of non-union, osteomyelitis, implant failure, sepsis, multiorgan dysfunction and even death. Surgical site infection is defined as pain, erythema, swelling and discharge from wound site. Surgical site infection in orthopaedic implants is more challenging to the treating orthopaedic surgeon as the causative organism is protected by a biofilm over the implant's surface. Antibiotics cannot cross this film to reach the bacteria's, causing infection. Method: This descriptive case series study includes 132 patients of both genders with ages between 13 years to 60 years conducted at Orthopaedic Unit, Ayub Medical College, Abbottabad from 1st October 2015 to 31st March 2016. Patients with close fractures of long bones were included in the study to determine the frequency of surgical site infection in orthopaedic implants and the type of bacteria involved and their sensitivity to various antibiotics. All implants were of stainless steel. The implants used were Dynamic hip screws, Dynamic compression screws, plates, k-wires, Interlocking nails, SIGN nails, Austin Moore prosthesis and tension band wires. Pre-op and post-op antibiotics used were combination of Sulbactum and Cefoperazone which was given 1 hour before surgery and continued for 72 hours after surgery. Patients were followed up to 4 weeks. Pus was taken on culture stick, from those who developed infection. Results were entered in the pro forma. Results: A total of 132 patients of long bone fractures, who were treated with open reduction and internal fixation, were studied. Only 7 patients developed infection. Staphylococcus Aureus was isolated from all 7 patients. Staphylococcus aureus was sensitive to Linezolid, Fusidic Acid, and vancomycin. Cotrimoxazole, tetracycline, Gentamycin and Clindamycin were partially effective. Conclusion

  2. Binding of 99mTc-labelled polyclonal human immunoglobulin to bacteria as a mechanism for scintigraphic detection of infection

    International Nuclear Information System (INIS)

    Calame, W.; Furth, R. van

    1991-01-01

    The aim of the present study was to determine whether 99m Tc-labelled polyclonal human immunoglobulin ( 99m Tc-HIG) binds to bacteria in vitro as well as in vivo. In vitro, the binding of 99m Tc-HIG to various gram-positive and gram-negative bacteria was determined. In vivo, mice were infected with Staphylococcus aureus Cowan I (protein A rich) or S. aureus EMS (protein A deficient) in a tigh muscle and then 99m Tc-HIG or 99m Tc-labelled human serum albumin ( 99m Tc-HSA) was administered; scintigrams were made 1, 4 and 18 h later. In vitro binding of 99m Tc-HIG to bacteria was higher for gram-positive than for gram-negative forms. A positive correlation was found between the protein A content and the degree of binding to S. aureus. This was also found in vivo. The accumulation of 99m Tc-HIG at the site of infection was significantly (P 99m Tc-HSA, for both strains of S. aureus. It is concluded that vascular permeability cannot fully explain the accumulation of 99m Tc-HIG at the site of infection and that binding of 99m Tc-HIG to bacteria plays a role in this respect. (orig.)

  3. Dietary modulation of the resistance to intestinal infections

    NARCIS (Netherlands)

    Bovee-Oudenhoven, I.M.J.

    1998-01-01

    Gastrointestinal infections are still a major health problem, not only in developing countries. Even in Europe and the United States about 10-15 % of the population contracts an intestinal infection each year, mostly of foodborne origin. The growing resistance of pathogens to antibiotics

  4. Dengue virus life cycle : viral and host factors modulating infectivity

    NARCIS (Netherlands)

    Rodenhuis-Zybert, Izabela A.; Wilschut, Jan; Smit, Jolanda M.

    Dengue virus (DENV 1-4) represents a major emerging arthropod-borne pathogen. All four DENV serotypes are prevalent in the (sub) tropical regions of the world and infect 50-100 million individuals annually. Whereas the majority of DENV infections proceed asymptomatically or result in self-limited

  5. Lactic-acid bacteria increase the survival of marine shrimp, Litopenaeus vannamei, after infection with Vibrio harveyi

    OpenAIRE

    Vieira, Felipe do Nascimento; Pedrotti, Fabiola Santiago; Buglione Neto, Celso Carlos; Mouriño, José Luiz Pedreira; Beltrame, Elpídio; Martins, Maurício Laterça; Ramirez, Cristina; Arana, Luis Alejandro Vinatea

    2007-01-01

    This study evaluated the survival, post-larvae quality, and the population of bacteria in Litopenaeus vannamei after the addition of two strains of lactic-acid bacteria (2 and B6) experimentally infected by Vibrio harveyi. Fifteen hundred nauplii were distributed in 20 L capacity tanks with four replicates. The survival of control animals was lower (21%) than that of animals fed with the strains B6 (50%) and 2 (44%). Total bacterial population in the water and larvae, as well as of the Vibrio...

  6. Assessment of the bacteria reduction in the infected root canal irradiated with diode laser

    International Nuclear Information System (INIS)

    Radaelli, Claudia Amaral Rabello de Mello

    2002-01-01

    High success rates are achieved in conventional endodontic treatment of vital pulp teeth. However, in cases of non-vital pulp, a decrease in the rate of success occurs due to difficulties in achieving a complete disinfection of the root canals system. Some bacteria, such as Enterococcus faecalis, are frequently found in cases of endodontic treatment failure due to their high resistance to the conventional endodontic treatment. The aim of this study was to evaluate the efficiency of a high power diode laser irradiation in bacterial reduction of contaminated canals associated with dressing compose by calcium hydroxide paste propylene glycol and camphorated paramonochlorophenol. Eighty-two root canals were infected in vitro with Enterococcus faecalis in a concentration of 1x10 8 CFU/ml. Specimens were high intensity irradiated with a diode laser model Opus 10, at a wavelength of 830 nm. Two different parameters were employed in continuous mode: 3 W and 2,5 W with a 360 μm optical fiber at an angle of approximately 5 degrees respect to the dentine surface during 5 seconds, in 4 applications, with 20 seconds intervals among them. After these proceedings specimens were vortexed in peptone water and dilutions performed. Aliquots of the dilution were plated on m-Enterococcus agar, incubated, and the Colonies Forming Units (CFU) of ali groups was counted. The results showed a significant reduction of bacteria on ali groups after laser irradiation. A high reduction rate was achieved: 98.5% immediately after the laser irradiation; 48 hours after, the reduction was of 96,73% and, finally, a 100% reduction was achieved through the combination of laser irradiation and a long lasting dressing of calcium hydroxide paste, propylene glycol and camphorated paramonochlorophenol. High rates of bacteria reduction were achieved using the parameter of 3 W in continuous mode with the power of 2,9473 KW/cm 2 . The temperature was monitored with a K-pipe thermocouple placed at the

  7. Extended spectrum beta lactamase (ESBL) producing bacteria urinary tract infections and complex pediatric urology.

    Science.gov (United States)

    Wragg, Ruth; Harris, Anna; Patel, Mitul; Robb, Andrew; Chandran, Harish; McCarthy, Liam

    2017-02-01

    Extended spectrum beta lactamase (ESBL) producing bacteria are resistant to most beta-lactam antibiotics including third-generation cephalosporins, quinolones and aminoglycosides. This resistance is plasmid-borne and can spread between species. Management of ESBL is challenging in children with recurrent urinary tract infections (UTIs) and complex urological abnormalities. We aim to quantify the risk in children and specifically in urological patients. Retrospective review of a microbiology database (April 2014 to November 2015). This identified urine isolates, pyuria, ESBL growth and patient demographics. Data analysis was by Chi square, Mann-Whitney U-test and ANOVA. A P value of 10×10 6 WC/L). 136 urine cultures (n=79 patients) grew purely ESBL. Overall, 5.2% of urine isolates were ESBL and 9.5% isolates with pyuria (>100×10 6 WC/L) had ESBL, whereas only 22/1032 (2.1%) with no pyuria, (Pantibiotics). Over the study period, there was no significant rise of the monthly incidence between 2014 and 2015 (ANOVA P=0.1). This study is the first to document the incidence of ESBL in children (5%), and estimate the frequency of possible plasmid transmission between bacterial species in children. This quantifies the risk of ESBL, especially to urology patients, and mandates better antibiotic stewardship. Level IIc. Copyright © 2017. Published by Elsevier Inc.

  8. Modulation of pathogen-induced CCL20 secretion from HT-29 human intestinal epithelial cells by commensal bacteria.

    LENUS (Irish Health Repository)

    Sibartie, Shomik

    2009-01-01

    BACKGROUND: Human intestinal epithelial cells (IECs) secrete the chemokine CCL20 in response to infection by various enteropathogenic bacteria or exposure to bacterial flagellin. CCL20 recruits immature dendritic cells and lymphocytes to target sites. Here we investigated IEC responses to various pathogenic and commensal bacteria as well as the modulatory effects of commensal bacteria on pathogen-induced CCL20 secretion. HT-29 human IECs were incubated with commensal bacteria (Bifidobacterium infantis or Lactobacillus salivarius), or with Salmonella typhimurium, its flagellin, Clostridium difficile, Mycobacterium paratuberculosis, or Mycobacterium smegmatis for varying times. In some studies, HT-29 cells were pre-treated with a commensal strain for 2 hr prior to infection or flagellin stimulation. CCL20 and interleukin (IL)-8 secretion and nuclear factor (NF)-kappaB activation were measured using enzyme-linked immunosorbent assays. RESULTS: Compared to untreated cells, S. typhimurium, C. difficile, M. paratuberculosis, and flagellin activated NF-kappaB and stimulated significant secretion of CCL20 and IL-8 by HT-29 cells. Conversely, B. infantis, L. salivarius or M. smegmatis did not activate NF-kappaB or augment CCL20 or IL-8 production. Treatment with B. infantis, but not L. salivarius, dose-dependently inhibited the baseline secretion of CCL20. In cells pre-treated with B. infantis, C. difficile-, S. typhimurium-, and flagellin-induced CCL20 were significantly attenuated. B. infantis did not limit M. Paratuberculosis-induced CCL20 secretion. CONCLUSION: This study is the first to demonstrate that a commensal strain can attenuate CCL20 secretion in HT-29 IECs. Collectively, the data indicate that M. paratuberculosis may mediate mucosal damage and that B. infantis can exert immunomodulatory effects on IECs that mediate host responses to flagellin and flagellated enteric pathogens.

  9. Predatory bacteria as natural modulators of Vibrio parahaemolyticus and Vibrio vulnificus in seawater and oysters

    Science.gov (United States)

    This study shows that naturally occurring Vibrio predatory bacteria (VPB) exert a major role in controlling pathogenic vibrios in seawater and shellfish. The growth and persistence of Vibrio parahaemolyticus (Vp) and Vibrio vulnificus (Vv) were assessed in natural seawater and in the Eastern oyster...

  10. Antimicrobial susceptibility pattern of bacteria isolated from patients with urinary tract infection

    International Nuclear Information System (INIS)

    Khan, I.U.; Mirza, I.A.; Ikram, A.; Afzal, A.; Ali, S.; Hussain, A.; Ghafoor, T.

    2014-01-01

    To determine the antimicrobial susceptibility pattern of bacterial pathogens in the patients of urinary tract infection reporting at a tertiary care hospital. Study Design: Laboratory based study. Place and Duration of Study: Department of Microbiology, Armed Forces Institute of Pathology, Rawalpindi, from January to December 2012. Methodology: A total of 440 culture positive bacterial isolates from 1110 urine samples; submitted over a period of one year were included in this study. Identification of bacterial isolates was done by standard biochemical profile of the organisms. The antimicrobial susceptibility of culture positive bacterial isolates was performed by disk diffusion method as recommended by Clinical Laboratory Standard Institute guidelines (CLSI). Results: Out of the 440 culture positive urine samples, 152 (34.6%) were from indoor patients whereas 288 (65.4%) from outdoor patients. Gram negative bacteria accounted for 414 (94%) of the total isolates while rest of the 26 (6%) were Gram positive bacteria. The most prevalent bacterial isolate was Escherichia (E.) coli 270 (61.3%) followed by Pseudomonas (P.) aeruginosa 52 (12%) and Klebsiella (K.) pneumoniae 42 (9.5%). The susceptibility pattern of E. coli showed that 96.2% of the bacterial isolates were sensitive to imipenem, 85.1% to amikacin, 80.7% to piperacillin/tazobactam and 72.6% to nitrofurantoin. In case of P. aeruginsosa, 73% bacterial isolates were sensitive to tazobactam/piperacillin, 69.2% to sulbactam/cefoperazone and 65.38% to imipenem. The antibiogram of K. pneumoniae has revealed that 76.1% of the bacterial isolates were sensitive to imipenem and 52.3% to piperacillin/tazobactam. Nitrofurantoin and imipenem were the most effective antimicrobials amongst the Enterococcus spp. as 92.3% showed susceptibility to this bacterial isolate. Conclusion: Majority of the bacterial isolates were sensitive to imipenem and piperacillin/tazobactam while susceptibility to most of the commonly used oral

  11. Polymicrobial Oral Infection with Four Periodontal Bacteria Orchestrates a Distinct Inflammatory Response and Atherosclerosis in ApoE null Mice.

    Science.gov (United States)

    Chukkapalli, Sasanka S; Velsko, Irina M; Rivera-Kweh, Mercedes F; Zheng, Donghang; Lucas, Alexandra R; Kesavalu, Lakshmyya

    2015-01-01

    Periodontal disease (PD) develops from a synergy of complex subgingival oral microbiome, and is linked to systemic inflammatory atherosclerotic vascular disease (ASVD). To investigate how a polybacterial microbiome infection influences atherosclerotic plaque progression, we infected the oral cavity of ApoE null mice with a polybacterial consortium of 4 well-characterized periodontal pathogens, Porphyromonas gingivalis, Treponema denticola, Tannerealla forsythia and Fusobacterium nucleatum, that have been identified in human atherosclerotic plaque by DNA screening. We assessed periodontal disease characteristics, hematogenous dissemination of bacteria, peripheral T cell response, serum inflammatory cytokines, atherosclerosis risk factors, atherosclerotic plaque development, and alteration of aortic gene expression. Polybacterial infections have established gingival colonization in ApoE null hyperlipidemic mice and displayed invasive characteristics with hematogenous dissemination into cardiovascular tissues such as the heart and aorta. Polybacterial infection induced significantly higher levels of serum risk factors oxidized LDL (p Periodontal microbiome infection is associated with significant decreases in Apoa1, Apob, Birc3, Fga, FgB genes that are associated with atherosclerosis. Periodontal infection for 12 weeks had modified levels of inflammatory molecules, with decreased Fas ligand, IL-13, SDF-1 and increased chemokine RANTES. In contrast, 24 weeks of infection induced new changes in other inflammatory molecules with reduced KC, MCSF, enhancing GM-CSF, IFNγ, IL-1β, IL-13, IL-4, IL-13, lymphotactin, RANTES, and also an increase in select inflammatory molecules. This study demonstrates unique differences in the host immune response to a polybacterial periodontal infection with atherosclerotic lesion progression in a mouse model.

  12. Saccharomyces boulardii Preserves the Barrier Function and Modulates the Signal Transduction Pathway Induced in Enteropathogenic Escherichia coli-Infected T84 Cells

    Science.gov (United States)

    Czerucka, Dorota; Dahan, Stephanie; Mograbi, Baharia; Rossi, Bernard; Rampal, Patrick

    2000-01-01

    Use of the nonpathogenic yeast Saccharomyces boulardii in the treatment of infectious diarrhea has attracted growing interest. The present study designed to investigate the effect of this yeast on enteropathogenic Escherichia coli (EPEC)-associated disease demonstrates that S. boulardii abrogated the alterations induced by an EPEC strain on transepithelial resistance, [3H]inulin flux, and ZO-1 distribution in T84 cells. Moreover, EPEC-mediated apoptosis of epithelial cells was delayed in the presence of S. boulardii. The yeast did not modify the number of adherent bacteria but lowered by 50% the number of intracellular bacteria. Infection by EPEC induced tyrosine phosphorylation of several proteins in T84 cells, including p46 and p52 SHC isoforms, that was attenuated in the presence of S. boulardii. Similarly, EPEC-induced activation of the ERK1/2 mitogen-activated protein (MAP) kinase pathway was diminished in the presence of the yeast. Interestingly, inhibition of the ERK1/2 pathway with the specific inhibitor PD 98059 decreased EPEC internalization, suggesting that modulation of the ERK1/2 MAP pathway might account for the lowering of the number of intracellular bacteria observed in the presence of S. boulardii. Altogether, this study demonstrated that S. boulardii exerts a protective effect on epithelial cells after EPEC adhesion by modulating the signaling pathway induced by bacterial infection. PMID:10992512

  13. Environmental contaminant mixtures modulate in vitro influenza infection

    DEFF Research Database (Denmark)

    Desforges, Jean-Pierre; Bandoro, Christopher; Shehata, Laila

    2018-01-01

    Environmental chemicals, particularly organochlorinated contaminants (OCs), are associated with a ranged of adverse health effects, including impairment of the immune system and antiviral immunity. Influenza A virus (IAV) is an infectious disease of major global public health concern and exposure...... studies such as ours can shed light on the complex processes underlying host-pathogen-pollutant interactions....... to OCs can increase the susceptibility, morbidity, and mortality to disease. It is however unclear how pollutants are interacting and affecting the outcome of viral infections at the cellular level. In this study, we investigated the effects of a mixture of environmentally relevant OCs on IAV infectivity...

  14. Priming of the Arabidopsis pattern-triggered immunity response upon infection by necrotrophic Pectobacterium carotovorum bacteria.

    Science.gov (United States)

    Po-Wen, Chen; Singh, Prashant; Zimmerli, Laurent

    2013-01-01

    Boosted responsiveness of plant cells to stress at the onset of pathogen- or chemically induced resistance is called priming. The chemical β-aminobutyric acid (BABA) enhances Arabidopsis thaliana resistance to hemibiotrophic bacteria through the priming of the salicylic acid (SA) defence response. Whether BABA increases Arabidopsis resistance to the necrotrophic bacterium Pectobacterium carotovorum ssp. carotovorum (Pcc) is not clear. In this work, we show that treatment with BABA protects Arabidopsis against the soft-rot pathogen Pcc. BABA did not prime the expression of the jasmonate/ethylene-responsive gene PLANT DEFENSIN 1.2 (PDF1.2), the up-regulation of which is usually associated with resistance to necrotrophic pathogens. Expression of the SA marker gene PATHOGENESIS RELATED 1 (PR1) on Pcc infection was primed by BABA treatment, but SA-defective mutants demonstrated a wild-type level of BABA-induced resistance against Pcc. BABA primed the expression of the pattern-triggered immunity (PTI)-responsive genes FLG22-INDUCED RECEPTOR-LIKE KINASE 1 (FRK1), ARABIDOPSIS NON-RACE SPECIFIC DISEASE RESISTANCE GENE (NDR1)/HAIRPIN-INDUCED GENE (HIN1)-LIKE 10 (NHL10) and CYTOCHROME P450, FAMILY 81 (CYP81F2) after inoculation with Pcc or after treatment with purified bacterial microbe-associated molecular patterns, such as flg22 or elf26. PTI-mediated callose deposition was also potentiated in BABA-treated Arabidopsis, and BABA boosted Arabidopsis stomatal immunity to Pcc. BABA treatment primed the PTI response in the SA-defective mutants SA induction deficient 2-1 (sid2-1) and phytoalexin deficient 4-1 (pad4-1). In addition, BABA priming was associated with open chromatin configurations in the promoter region of PTI marker genes. Our data indicate that BABA primes the PTI response upon necrotrophic bacterial infection and suggest a role for the PTI response in BABA-induced resistance. © 2012 THE AUTHORS. MOLECULAR PLANT PATHOLOGY © 2012 BSPP AND BLACKWELL PUBLISHING LTD.

  15. Environmental modulation of mucosal immunity : Opportunities in respiratory viral infections

    NARCIS (Netherlands)

    Schijf, M.A.

    2013-01-01

    The exact cause of severe disease in children during primary RSV infections is not completely clear. There is a link with viral load, but differences virus strains do not seem to be the major reason why in some children the disease manifests as a mild cold while others suffer from a severe lower

  16. Host age modulates parasite infectivity, virulence and reproduction.

    Science.gov (United States)

    Izhar, Rony; Ben-Ami, Frida

    2015-07-01

    Host age is one of the most striking differences among hosts within most populations, but there is very little data on how age-dependent effects impact ecological and evolutionary dynamics of both the host and the parasite. Here, we examined the influence of host age (juveniles, young and old adults) at parasite exposure on host susceptibility, fecundity and survival as well as parasite transmission, using two clones of the water flea Daphnia magna and two clones of its bacterial parasite Pasteuria ramosa. Younger D. magna were more susceptible to infection than older ones, regardless of host or parasite clone. Also, younger-infected D. magna became castrated faster than older hosts, but host and parasite clone effects contributed to this trait as well. Furthermore, the early-infected D. magna produced considerably more parasite transmission stages than late-infected ones, while host age at exposure did not affect virulence as it is defined in models (host mortality). When virulence is defined more broadly as the negative effects of infection on host fitness, by integrating the parasitic effects on host fecundity and mortality, then host age at exposure seems to slide along a negative relationship between host and parasite fitness. Thus, the virulence-transmission trade-off differs strongly among age classes, which in turn affects predictions of optimal virulence. Age-dependent effects on host susceptibility, virulence and parasite transmission could pose an important challenge for experimental and theoretical studies of infectious disease dynamics and disease ecology. Our results present a call for a more explicit stage-structured theory for disease, which will incorporate age-dependent epidemiological parameters. © 2015 The Authors. Journal of Animal Ecology © 2015 British Ecological Society.

  17. Trematode infection modulates cockles biochemical response to climate change.

    Science.gov (United States)

    Magalhães, Luísa; de Montaudouin, Xavier; Figueira, Etelvina; Freitas, Rosa

    2018-05-06

    Resulting mainly from atmospheric carbon dioxide (CO 2 ) build-up, seawater temperature rise is among the most important climate change related factors affecting costal marine ecosystems. Global warming will have implications on the water cycle, increasing the risk of heavy rainfalls and consequent freshwater input into the oceans but also increasing the frequency of extreme drought periods with consequent salinity increase. For Europe, by the end of the century, projections describe an increase of CO 2 concentration up to 1120 ppm (corresponding to 0.5 pH unit decrease), an increase in the water temperature up to 4 °C and a higher frequency of heavy precipitation. These changes are likely to impact many biotic interactions, including host-parasite relationships which are particularly dependent on abiotic conditions. In the present study, we tested the hypothesis that the edible cockle, Cerastoderma edule, exposed to different salinity, temperature and pH levels as proxy for climate change, modify the infection success of the trematode parasite Himasthla elongata, with consequences to cockles biochemical performance. The results showed that the cercariae infection success increased with acidification but higher biochemical alterations were observed in infected cockles exposed to all abiotic experimental stressful conditions tested. The present study suggested that changes forecasted by many models may promote the proliferation of the parasites infective stages in many ecosystems leading to enhanced transmission, especially on temperate regions, that will influence the geographical distribution of some diseases and, probably, the survival capacity of infected bivalves. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. A gastrointestinal rotavirus infection mouse model for immune modulation studies

    Directory of Open Access Journals (Sweden)

    van Amerongen Geert

    2011-03-01

    Full Text Available Abstract Background Rotaviruses are the single most important cause of severe diarrhea in young children worldwide. The current study was conducted to assess whether colostrum containing rotavirus-specific antibodies (Gastrogard-R® could protect against rotavirus infection. In addition, this illness model was used to study modulatory effects of intervention on several immune parameters after re-infection. Methods BALB/c mice were treated by gavage once daily with Gastrogard-R® from the age of 4 to 10 days, and were inoculated with rhesus rotavirus (RRV at 7 days of age. A secondary inoculation with epizootic-diarrhea infant-mouse (EDIM virus was administered at 17 days of age. Disease symptoms were scored daily and viral shedding was measured in fecal samples during the post-inoculation periods. Rotavirus-specific IgM, IgG and IgG subclasses in serum, T cell proliferation and rotavirus-specific delayed-type hypersensitivity (DTH responses were also measured. Results Primary inoculation with RRV induced a mild but consistent level of diarrhea during 3-4 days post-inoculation. All mice receiving Gastrogard-R® were 100% protected against rotavirus-induced diarrhea. Mice receiving both RRV and EDIM inoculation had a lower faecal-viral load following EDIM inoculation then mice receiving EDIM alone or Gastrogard-R®. Mice receiving Gastrogard-R® however displayed an enhanced rotavirus-specific T-cell proliferation whereas rotavirus-specific antibody subtypes were not affected. Conclusions Preventing RRV-induced diarrhea by Gastrogard-R® early in life showed a diminished protection against EDIM re-infection, but a rotavirus-specific immune response was developed including both B cell and T cell responses. In general, this intervention model can be used for studying clinical symptoms as well as the immune responses required for protection against viral re-infection.

  19. Childhood urinary tract infection caused by extended-spectrum β-lactamase-producing bacteria: Risk factors and empiric therapy.

    Science.gov (United States)

    Uyar Aksu, Nihal; Ekinci, Zelal; Dündar, Devrim; Baydemir, Canan

    2017-02-01

    This study investigated risk factors of childhood urinary tract infection (UTI) associated with extended-spectrum β-lactamase (ESBL)-producing bacteria (ESBL-positive UTI) and evaluated antimicrobial resistance as well as empiric treatment of childhood UTI. The records of children with positive urine culture between 1 January 2008 and 31 December 2012 were evaluated. Patients with positive urine culture for ESBL-producing bacteria were defined as the ESBL-positive group, whereas patients of the same gender and similar age with positive urine culture for non-ESBL-producing bacteria were defined as the ESBL-negative group. Each ESBL-positive patient was matched with two ESBL-negative patients. The ESBL-positive and negative groups consisted of 154 and 308 patients, respectively. Potential risk factors for ESBL-positive UTI were identified as presence of underlying disease, clean intermittent catheterization (CIC), hospitalization, use of any antibiotic and history of infection in the last 3 months (P infection in the last 3 months were identified as independent risk factors. In the present study, 324 of 462 patients had empiric therapy. Empiric therapy was inappropriate in 90.3% of the ESBL-positive group and in 4.5% of the ESBL-negative group. Resistance to nitrofurantoin was similar between groups (5.1% vs 1.2%, P = 0.072); resistance to amikacin was low in the ESBL-positive group (2.6%) and there was no resistance in the ESBL-negative group. Clean intermittent catheterization, hospitalization and history of infection in the last 3 months should be considered as risk factors for ESBL-positive UTI. The combination of ampicillin plus amikacin should be taken into consideration for empiric therapy in patients with acute pyelonephritis who have the risk factors for ESBL-positive UTI. Nitrofurantoin seems to be a logical choice for the empiric therapy of cystitis. © 2016 Japan Pediatric Society.

  20. Periodontal Bacteria and Prediabetes Prevalence in ORIGINS: The Oral Infections, Glucose Intolerance, and Insulin Resistance Study.

    Science.gov (United States)

    Demmer, R T; Jacobs, D R; Singh, R; Zuk, A; Rosenbaum, M; Papapanou, P N; Desvarieux, M

    2015-09-01

    Periodontitis and type 2 diabetes mellitus are known to be associated. The relationship between periodontal microbiota and early diabetes risk has not been studied. We investigated the association between periodontal bacteria and prediabetes prevalence among diabetes-free adults. ORIGINS (the Oral Infections, Glucose Intolerance and Insulin Resistance Study) cross sectionally enrolled 300 diabetes-free adults aged 20 to 55 y (mean ± SD, 34 ± 10 y; 77% female). Prediabetes was defined as follows: 1) hemoglobin A1c values ranging from 5.7% to 6.4% or 2) fasting plasma glucose ranging from 100 to 125 mg/dL. In 1,188 subgingival plaque samples, 11 bacterial species were assessed at baseline, including Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, and Actinomyces naeslundii. Full-mouth clinical periodontal examinations were performed, and participants were defined as having no/mild periodontitis vs. moderate/severe periodontitis per the definition of the Centers for Disease Control and Prevention / American Academy of Periodontology. Modified Poisson regression evaluated prediabetes prevalence across bacterial tertiles. Prevalence ratios and 95% confidence intervals for third vs. first tertiles are presented. All analyses were adjusted for cardiometabolic risk factors. All results presented currently arise from the baseline cross section. Prediabetes prevalence was 18%, and 58% of participants had moderate/severe periodontitis. Prevalence ratios (95% confidence intervals) summarizing associations between bacterial levels and prediabetes were as follows: A. actinomycetemcomitans, 2.48 (1.34, 4.58), P = 0.004; P. gingivalis, 3.41 (1.78, 6.58), P = 0.0003; T. denticola, 1.99 (0.992, 4.00), P = 0.052; T. forsythia, 1.95 (1.0, 3.84), P = 0.05; A. naeslundii, 0.46 (0.25, 0.85), P = 0.01. The prevalence ratio for prediabetes among participants with moderate/severe vs. no/mild periodontitis was 1.47 (0.78, 2.74), P

  1. Monitoring in vitro antibacterial efficacy of 26 Indian spices against multidrug resistant urinary tract infecting bacteria

    Directory of Open Access Journals (Sweden)

    Sibanarayan Rath

    2014-09-01

    Conclusion: The most effective and unique 16 spice plants recorded for the in vitro control of MDR uropathogens could further be pursued for the development of complementary and supplementary medicine against MDR bacteria.

  2. The Use of Predatory Bacteria to Control Select Pathogens and Treat Respiratory Infections

    Science.gov (United States)

    2015-04-13

    V. et al. The development of a multiplex real-time PCR to quantify Fusarium DNA of trichothecene and fumonisin producing strains in maize ...AND ADDRESS (ES) U.S. Army Research Office P.O. Box 12211 Research Triangle Park, NC 27709-2211 Predatory bacteria, Bdellovibrio bacteriovorus...of Papers published in peer-reviewed journals : Number of Papers published in non peer-reviewed journals : Final Report: The Use of Predatory Bacteria

  3. Differential protein modulation in midguts of Aedes aegypti infected with chikungunya and dengue 2 viruses.

    Directory of Open Access Journals (Sweden)

    Stéphane Tchankouo-Nguetcheu

    Full Text Available BACKGROUND: Arthropod borne virus infections cause several emerging and resurgent infectious diseases. Among the diseases caused by arboviruses, dengue and chikungunya are responsible for a high rate of severe human diseases worldwide. The midgut of mosquitoes is the first barrier for pathogen transmission and is a target organ where arboviruses must replicate prior to infecting other organs. A proteomic approach was undertaken to characterize the key virus/vector interactions and host protein modifications that happen in the midgut for viral transmission to eventually take place. METHODOLOGY AND PRINCIPAL FINDINGS: Using a proteomics differential approach with two-Dimensional Differential in-Gel Electrophoresis (2D-DIGE, we defined the protein modulations in the midgut of Aedes aegypti that were triggered seven days after an oral infection (7 DPI with dengue 2 (DENV-2 and chikungunya (CHIKV viruses. Gel profile comparisons showed that the level of 18 proteins was modulated by DENV-2 only and 12 proteins were modulated by CHIKV only. Twenty proteins were regulated by both viruses in either similar or different ways. Both viruses caused an increase of proteins involved in the generation of reactive oxygen species, energy production, and carbohydrate and lipid metabolism. Midgut infection by DENV-2 and CHIKV triggered an antioxidant response. CHIKV infection produced an increase of proteins involved in detoxification. CONCLUSION/SIGNIFICANCE: Our study constitutes the first analysis of the protein response of Aedes aegypti's midgut infected with viruses belonging to different families. It shows that the differentially regulated proteins in response to viral infection include structural, redox, regulatory proteins, and enzymes for several metabolic pathways. Some of these proteins like antioxidant are probably involved in cell protection. On the other hand, we propose that the modulation of other proteins like transferrin, hsp60 and alpha

  4. Differential protein modulation in midguts of Aedes aegypti infected with chikungunya and dengue 2 viruses.

    Science.gov (United States)

    Tchankouo-Nguetcheu, Stéphane; Khun, Huot; Pincet, Laurence; Roux, Pascal; Bahut, Muriel; Huerre, Michel; Guette, Catherine; Choumet, Valérie

    2010-10-05

    Arthropod borne virus infections cause several emerging and resurgent infectious diseases. Among the diseases caused by arboviruses, dengue and chikungunya are responsible for a high rate of severe human diseases worldwide. The midgut of mosquitoes is the first barrier for pathogen transmission and is a target organ where arboviruses must replicate prior to infecting other organs. A proteomic approach was undertaken to characterize the key virus/vector interactions and host protein modifications that happen in the midgut for viral transmission to eventually take place. Using a proteomics differential approach with two-Dimensional Differential in-Gel Electrophoresis (2D-DIGE), we defined the protein modulations in the midgut of Aedes aegypti that were triggered seven days after an oral infection (7 DPI) with dengue 2 (DENV-2) and chikungunya (CHIKV) viruses. Gel profile comparisons showed that the level of 18 proteins was modulated by DENV-2 only and 12 proteins were modulated by CHIKV only. Twenty proteins were regulated by both viruses in either similar or different ways. Both viruses caused an increase of proteins involved in the generation of reactive oxygen species, energy production, and carbohydrate and lipid metabolism. Midgut infection by DENV-2 and CHIKV triggered an antioxidant response. CHIKV infection produced an increase of proteins involved in detoxification. Our study constitutes the first analysis of the protein response of Aedes aegypti's midgut infected with viruses belonging to different families. It shows that the differentially regulated proteins in response to viral infection include structural, redox, regulatory proteins, and enzymes for several metabolic pathways. Some of these proteins like antioxidant are probably involved in cell protection. On the other hand, we propose that the modulation of other proteins like transferrin, hsp60 and alpha glucosidase, may favour virus survival, replication and transmission, suggesting a subversion of

  5. Mucosal and systemic immune modulation by Trichuris trichiura in a self-infected individual

    DEFF Research Database (Denmark)

    Dige, Anders Kirch; Rasmussen, Tue Kruse; Nejsum, Peter

    2017-01-01

    Helminthic therapy of immune-mediated diseases has gained attention in recent years, but we know little of how helminths modulate human immunity. In this study, we investigated how self-infection with Trichuris (T.) trichiura in an adult man without intestinal disease affected mucosal and systemic...

  6. Lipoteichoic Acid (LTA) and Lipopolysaccharides (LPS) from Periodontal Pathogenic Bacteria Facilitate Oncogenic Herpesvirus Infection within Primary Oral Cells

    Science.gov (United States)

    Dai, Lu; DeFee, Michael R.; Cao, Yueyu; Wen, Jiling; Wen, Xiaofei; Noverr, Mairi C.; Qin, Zhiqiang

    2014-01-01

    Kaposi’s sarcoma (KS) remains the most common tumor arising in patients with HIV/AIDS, and involvement of the oral cavity represents one of the most common clinical manifestations of this tumor. HIV infection incurs an increased risk for periodontal diseases and oral carriage of a variety of bacteria. Whether interactions involving pathogenic bacteria and oncogenic viruses in the local environment facilitate replication or maintenance of these viruses in the oral cavity remains unknown. In the current study, our data indicate that pretreatment of primary human oral fibroblasts with two prototypical pathogen-associated molecular patterns (PAMPs) produced by oral pathogenic bacteria–lipoteichoic acid (LTA) and lipopolysaccharide (LPS), increase KSHV entry and subsequent viral latent gene expression during de novo infection. Further experiments demonstrate that the underlying mechanisms induced by LTA and/or LPS include upregulation of cellular receptor, increasing production of reactive oxygen species (ROS), and activating intracellular signaling pathways such as MAPK and NF-κB, and all of which are closely associated with KSHV entry or gene expression within oral cells. Based on these findings, we hope to provide the framework of developing novel targeted approaches for treatment and prevention of oral KSHV infection and KS development in high-risk HIV-positive patients. PMID:24971655

  7. Urinary tract infection (UTI) multi-bacteria multi-antibiotic testing using surface enhanced Raman spectroscopy (SERS)

    Science.gov (United States)

    Hadjigeorgiou, Katerina; Kastanos, Evdokia; Pitris, Costas

    2013-02-01

    Antibiotic resistance is a major health care problem mostly caused by the inappropriate use of antibiotics. At the root of the problem lies the current method for determination of bacterial susceptibility to antibiotics which requires overnight cultures. Physicians suspecting an infection usually prescribe an antibiotic without waiting for the results. This practice aggravates the problem of bacterial resistance. In this work, a rapid method of diagnosis and antibiogram for a bacterial infection was developed using Surface Enhanced Raman Spectroscopy (SERS) with silver nanoparticles. SERS spectra of three species of gram negative bacteria, Escherichia coli, Proteus spp., and Klebsiella spp. were obtained after 0 and 4 hour exposure to the seven different antibiotics. Even though the concentration of bacteria was low (2x105 cfu/ml), species classification was achieved with 94% accuracy using spectra obtained at 0 hours. Sensitivity or resistance to antibiotics was predicted with 81%-100% accuracy from spectra obtained after 4 hours of exposure to the different antibiotics. With the enhancement provided by SERS, the technique can be applied directly to urine or blood samples, bypassing the need for overnight cultures. This technology can lead to the development of rapid methods of diagnosis and antibiogram for a variety of bacterial infections.

  8. Multi-bacteria multi-antibiotic testing using surface enhanced Raman spectroscopy (SERS) for urinary tract infection (UTI) diagnosis

    Science.gov (United States)

    Hadjigeorgiou, Katerina; Kastanos, Evdokia; Pitris, Costas

    2013-06-01

    The inappropriate use of antibiotics leads to antibiotic resistance, which is a major health care problem. The current method for determination of bacterial susceptibility to antibiotics requires overnight cultures. However most of the infections cannot wait for the results to receive treatment, so physicians administer general spectrum antibiotics. This results in ineffective treatments and aggravates the rising problem of antibiotic resistance. In this work, a rapid method for diagnosis and antibiogram for a bacterial infection was developed using Surface Enhanced Raman Spectroscopy (SERS) with silver nanoparticles. The advantages of this novel method include its rapidness and efficiency which will potentially allow doctors to prescribe the most appropriate antibiotic for an infection. SERS spectra of three species of gram negative bacteria, Escherichia coli, Proteus spp., and Klebsiella spp. were obtained after 0 and 4 hour exposure to the seven different antibiotics. Bacterial strains were diluted in order to reach the concentration of (2x105 cfu/ml), cells/ml which is equivalent to the minimum concentration found in urine samples from UTIs. Even though the concentration of bacteria was low, species classification was achieved with 94% accuracy using spectra obtained at 0 hours. Sensitivity or resistance to antibiotics was predicted with 81%-100% accuracy from spectra obtained after 4 hours of exposure to the different antibiotics. This technique can be applied directly to urine samples, and with the enhancement provided by SERS, this method has the potential to be developed into a rapid method for same day UTI diagnosis and antibiogram.

  9. Clofazimine modulates the expression of lipid metabolism proteins in Mycobacterium leprae-infected macrophages.

    Science.gov (United States)

    Degang, Yang; Akama, Takeshi; Hara, Takeshi; Tanigawa, Kazunari; Ishido, Yuko; Gidoh, Masaichi; Makino, Masahiko; Ishii, Norihisa; Suzuki, Koichi

    2012-01-01

    Mycobacterium leprae (M. leprae) lives and replicates within macrophages in a foamy, lipid-laden phagosome. The lipids provide essential nutrition for the mycobacteria, and M. leprae infection modulates expression of important host proteins related to lipid metabolism. Thus, M. leprae infection increases the expression of adipophilin/adipose differentiation-related protein (ADRP) and decreases hormone-sensitive lipase (HSL), facilitating the accumulation and maintenance of lipid-rich environments suitable for the intracellular survival of M. leprae. HSL levels are not detectable in skin smear specimens taken from leprosy patients, but re-appear shortly after multidrug therapy (MDT). This study examined the effect of MDT components on host lipid metabolism in vitro, and the outcome of rifampicin, dapsone and clofazimine treatment on ADRP and HSL expression in THP-1 cells. Clofazimine attenuated the mRNA and protein levels of ADRP in M. leprae-infected cells, while those of HSL were increased. Rifampicin and dapsone did not show any significant effects on ADRP and HSL expression levels. A transient increase of interferon (IFN)-β and IFN-γ mRNA was also observed in cells infected with M. leprae and treated with clofazimine. Lipid droplets accumulated by M. leprae-infection were significantly decreased 48 h after clofazimine treatment. Such effects were not evident in cells without M. leprae infection. In clinical samples, ADRP expression was decreased and HSL expression was increased after treatment. These results suggest that clofazimine modulates lipid metabolism in M. leprae-infected macrophages by modulating the expression of ADRP and HSL. It also induces IFN production in M. leprae-infected cells. The resultant decrease in lipid accumulation, increase in lipolysis, and activation of innate immunity may be some of the key actions of clofazimine.

  10. Critical Role of Airway Macrophages in Modulating Disease Severity during Influenza Virus Infection of Mice ▿

    Science.gov (United States)

    Tate, Michelle D.; Pickett, Danielle L.; van Rooijen, Nico; Brooks, Andrew G.; Reading, Patrick C.

    2010-01-01

    Airway macrophages provide a first line of host defense against a range of airborne pathogens, including influenza virus. In this study, we show that influenza viruses differ markedly in their abilities to infect murine macrophages in vitro and that infection of macrophages is nonproductive and no infectious virus is released. Virus strain BJx109 (H3N2) infected macrophages with high efficiency and was associated with mild disease following intranasal infection of mice. In contrast, virus strain PR8 (H1N1) was poor in its ability to infect macrophages and highly virulent for mice. Depletion of airway macrophages by clodronate-loaded liposomes led to the development of severe viral pneumonia in BJx109-infected mice but did not modulate disease severity in PR8-infected mice. The severe disease observed in macrophage-depleted mice infected with BJx109 was associated with exacerbated virus replication in the airways, leading to severe airway inflammation, pulmonary edema, and vascular leakage, indicative of lung injury. Thymic atrophy, lymphopenia, and dysregulated cytokine and chemokine production were additional systemic manifestations associated with severe disease. Thus, airway macrophages play a critical role in limiting lung injury and associated disease caused by BJx109. Furthermore, the inability of PR8 to infect airway macrophages may be a critical factor contributing to its virulence for mice. PMID:20504924

  11. Cutoff values for bacteria and leukocytes for urine sediment analyzer FUS200 in culture-positive urinary-tract infections.

    Science.gov (United States)

    Kocer, Derya; Sarıguzel, Fatma M; Karakukcu, Cıgdem

    2014-08-01

    The microscopic analysis of urine is essential for the diagnosis of patients with urinary tract infections. Quantitative urine culture is the 'gold standard' method for definitive diagnosis of urinary-tract infections, but it is labor-intensive, time consuming, and does not provide the same-day results. The aim of this study was to evaluate the analytical and diagnostic performance of the FUS200 (Changchun Dirui Industry, China), a new urine sedimentation analyzer in comparison to urine culture as the reference method. We evaluated 1000 urine samples, submitted for culture and urine analysis with a preliminary diagnosis of urinary-tract infection. Cut-off values for the FUS200 were determined by comparing the results with urine cultures. The cut-off values by the receiver operating characteristic (ROC) curve technique, sensitivity, and specificity were calculated for bacteria and white blood cells (WBCs). Among the 1000 urine specimens submitted for culture, 637 cultures (63.7%) were negative, and 363 were (36.3%) positive. The best cut-off values obtained from ROC analysis were 16/μL for bacteriuria (sensitivity: 82.3%, specificity: 58%), and 34/μL for WBCs (sensitivity: 72.3%, specificity: 65.2%). The area under the curve (AUC) for the bacteria and WBCs count were 0.71 (95% CI: 0.67-0.74) and, 0.72 (95% CI: 0.69-0.76) respectively. The most important requirement of a rapid diagnostic screening test is sensitivity, and, in this perspective, an unsatisfactory sensitivity by using bacteria recognition and quantification performed by the FUS200 analyzer has been observed. After further technical improvements in particle recognition and laboratory personnel training, the FUS200 might show better results.

  12. Bactericidal activity of the Ti-13Nb-13Zr alloy against different species of bacteria related with implant infection.

    Science.gov (United States)

    Aguilera-Correa, John-Jairo; Conde, Ana; Arenas, Maria-Angeles; de-Damborenea, Juan-Jose; Marin, Miguel; Doadrio, Antonio L; Esteban, Jaime

    2017-08-11

    The Ti-6Al-4V alloy is one of the most commonly used in orthopedic surgery. Despite its advantages, there is an increasing need to use new titanium alloys with no toxic elements and improved biomechanical properties, such as Ti-13Nb-13Zr. Prosthetic joint infections (PJI) are mainly caused by Gram-positive bacteria; however, Gram-negative bacteria are a growing problem due to associated multidrug resistance. In this study, the bacterial adherence and viability on the Ti-13Nb-13Zr alloy have been compared to that of the Ti-6Al-4V alloy using 16 collection and clinical strains of bacterial species related to PJI: Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, and Pseudomonas aeruginosa. When compared with the Ti-6Al-4V alloy, bacterial adherence on the Ti-13Nb-13Zr alloy was significantly higher in most staphylococcal and P. aeruginosa strains and lower for E. coli strains. The proportion of live bacteria was significantly lower for both Gram-negative species on the Ti-13Nb-13Zr alloy than on the Ti-6Al-4V alloy pointing to some bactericidal effect of the Ti-13Nb-13Zr alloy. This bactericidal effect appears to be a consequence of the formation of hydroxyl radicals, since this effect is neutralized when dimethylsulfoxide was added to both the saline solution and water used to wash the stain. The antibacterial effect of the Ti-13Nb-13Zr alloy against Gram-negative bacteria is an interesting property useful for the prevention of PJI caused by these bacteria on this potential alternative to the Ti-6Al-4V alloy for orthopedic surgery.

  13. Genetic battle between Helicobacter pylori and humans. The mechanism underlying homologous recombination in bacteria, which can infect human cells.

    Science.gov (United States)

    Hanada, Katsuhiro; Yamaoka, Yoshio

    2014-10-01

    Helicobacter pylori is a gram-negative pathogenic bacterium that colonises the human stomach. The chronic infection it causes results in peptic ulcers and gastric cancers. H. pylori can easily establish a chronic infection even if the immune system attacks this pathogen with oxidative stress agents and immunoglobulins. This is attributed to bacterial defence mechanisms against these stresses. As a defence mechanism against oxidative stresses, in bacterial genomes, homologous recombination can act as a repair pathway of DNA's double-strand breaks (DSBs). Moreover, homologous recombination is also involved in the antigenic variation in H. pylori. Gene conversion alters genomic structures of babA and babB (encoding outer membrane proteins), resulting in escape from immunoglobulin attacks. Thus, homologous recombination in bacteria plays an important role in the maintenance of a chronic infection. In addition, H. pylori infection causes DSBs in human cells. Homologous recombination is also involved in the repair of DSBs in human cells. In this review, we describe the roles of homologous recombination with an emphasis on the maintenance of a chronic infection. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

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

    Science.gov (United States)

    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.

  15. Cervicovaginal bacteria are a major modulator of host inflammatory responses in the female genital tract.

    Science.gov (United States)

    Anahtar, Melis N; Byrne, Elizabeth H; Doherty, Kathleen E; Bowman, Brittany A; Yamamoto, Hidemi S; Soumillon, Magali; Padavattan, Nikita; Ismail, Nasreen; Moodley, Amber; Sabatini, Mary E; Ghebremichael, Musie S; Nusbaum, Chad; Huttenhower, Curtis; Virgin, Herbert W; Ndung'u, Thumbi; Dong, Krista L; Walker, Bruce D; Fichorova, Raina N; Kwon, Douglas S

    2015-05-19

    Colonization by Lactobacillus in the female genital tract is thought to be critical for maintaining genital health. However, little is known about how genital microbiota influence host immune function and modulate disease susceptibility. We studied a cohort of asymptomatic young South African women and found that the majority of participants had genital communities with low Lactobacillus abundance and high ecological diversity. High-diversity communities strongly correlated with genital pro-inflammatory cytokine concentrations in both cross-sectional and longitudinal analyses. Transcriptional profiling suggested that genital antigen-presenting cells sense gram-negative bacterial products in situ via Toll-like receptor 4 signaling, contributing to genital inflammation through activation of the NF-κB signaling pathway and recruitment of lymphocytes by chemokine production. Our study proposes a mechanism by which cervicovaginal microbiota impact genital inflammation and thereby might affect a woman's reproductive health, including her risk of acquiring HIV. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Anaerobic bacteria in upper respiratory tract and head and neck infections: microbiology and treatment.

    Science.gov (United States)

    Brook, Itzhak

    2012-04-01

    Anaerobes are the predominant components of oropharyngeal mucous membranes bacterial flora, and are therefore a common cause of bacterial infections of endogenous origin of upper respiratory tract and head and neck. This review summarizes the aerobic and anaerobic microbiology and antimicrobials therapy of these infections. These include acute and chronic otitis media, mastoiditis and sinusitis, pharyngo-tonsillitis, peritonsillar, retropharyngeal and parapharyngeal abscesses, suppurative thyroiditis, cervical lymphadenitis, parotitis, siliadenitis, and deep neck infections including Lemierre Syndrome. The recovery from these infections depends on prompt and proper medical and when indicated also surgical management. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. European multicenter study on antimicrobial resistance in bacteria isolated from companion animal urinary tract infections

    NARCIS (Netherlands)

    Marques, Cátia; Gama, Luís Telo; Belas, Adriana; Bergström, Karin; Beurlet, Stéphanie; Briend-Marchal, Alexandra; Broens, Els M|info:eu-repo/dai/nl/314627723; Costa, Marta; Criel, Delphine; Damborg, Peter; van Dijk, Marloes A M|info:eu-repo/dai/nl/413392058; van Dongen, A.M.|info:eu-repo/dai/nl/097672637; Dorsch, Roswitha; Espada, Carmen Martin; Gerber, Bernhard; Kritsepi-Konstantinou, Maria; Loncaric, Igor; Mion, Domenico; Misic, Dusan; Movilla, Rebeca; Overesch, Gudrun; Perreten, Vincent; Roura, Xavier; Steenbergen, Joachim; Timofte, Dorina; Wolf, Georg; Zanoni, Renato Giulio; Schmitt, Sarah; Guardabassi, Luca; Pomba, Constança

    2016-01-01

    BACKGROUND: There is a growing concern regarding the increase of antimicrobial resistant bacteria in companion animals. Yet, there are no studies comparing the resistance levels of these organisms in European countries. The aim of this study was to investigate geographical and temporal trends of

  18. European multicenter study on antimicrobial resistance in bacteria isolated from companion animal urinary tract infections

    DEFF Research Database (Denmark)

    Marques, Cátia; Gama, Luís Telo; Belas, Adriana

    2016-01-01

    for fluoroquinolone-resistant Proteus spp. isolated from companion animals from Belgium. CONCLUSIONS: This work brings new insights into the current status of antimicrobial resistance in bacteria isolated from companion animals with UTI in Europe and reinforces the need for strategies aiming to reduce resistance....

  19. Helicobacter infections with rare bacteria or minimal gastritis: Expecting the unexpected.

    Science.gov (United States)

    Glickman, Jonathan N; Noffsinger, Amy; Nevin, Daniel T; Ray, Mukunda; Lash, Richard H; Genta, Robert M

    2015-07-01

    The routine use of special stains for detection of Helicobacter remains controversial. To determine the frequency of histologically atypical Helicobacter infection. All gastric biopsies received at a large pathology reference laboratory over a 6-month period were stained for Helicobacter, and the histologic and clinicopathologic parameters evaluated. Amongst 7663 Helicobacter-positive biopsies, 823 (10.7%) did not show typical chronic active gastritis with numerous Helicobacter organisms, and were therefore considered histologically atypical. Rare Helicobacter pylori organisms accounted for 58.0% of all atypical infections; the next most common atypical Helicobacter infection was that with minimal or no gastric inflammation (23.3% of atypical infections). Patients in these groups did not differ demographically from those with other forms of atypical or typical Helicobacter infection, although a small subgroup (6%) was more likely to have had a previously treated infection. In many of these atypical infections, Helicobacter would not have been suspected based on the histologic findings alone, and would have been missed without routine special stains. Performing a sensitive stain could prevent additional testing and allow prompt treatment of the affected patients, thus substantially reducing the risk for peptic ulcer and gastric cancer and preventing the transmission of the infection to family members. Copyright © 2015 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

  20. Non-destructive evaluation of bacteria-infected watermelon seeds using Vis/NIR hyperspectral imaging

    Science.gov (United States)

    It is needed to minimize the economic loss by sorting infected seeds from healthy seeds before seeding. However, current methods of detecting infection seeds such as seedling grow-out, enzyme-linked immunosorbent assay (ELISA), polymerase chain reaction (PCR), and real-time polymerase chain reaction...

  1. Electrochemical sensing of biomarker for diagnostics of bacteria-specific infections

    DEFF Research Database (Denmark)

    Al Atraktchi, Fatima Al-Zahraa; Johansen, Helle Krogh; Molin, Søren

    2016-01-01

    Aim: Pseudomonas aeruginosa is a pathogen that is prevalent in serious infections in compromised patients worldwide. A unique virulence factor of this bacterium is the redox-active molecule pyocyanin, which is a potential biomarker for the identification of P. aeruginosa infections. Here we repor...

  2. Soft tissue infections from fish spike wounds: normal commensal bacteria are more common than marine pathogens.

    Science.gov (United States)

    Collins, Hannah; Lee, Kin Mun; Cheng, Paul T-Y; Hulme, Sarah

    2018-01-01

    A fish spike injury can be sustained by anyone handling fish; during fishing, meal preparation or in retail. Case reports of fish spikes inoculating victims with virulent marine-specific pathogens and causing systemic illness led us to question whether empirical treatment of these injuries with amoxicillin and clavulanic acid is adequate. This 2-year prospective observational study was conducted at Middlemore Hospital, Auckland, New Zealand. Wound swabs and tissue samples belonging to patients presenting to the Department of Plastic and Reconstructive Surgery with an upper limb fish spike injury were sent to the laboratory (n = 60). A series of stains and cultures were performed to look specifically for marine bacteria not typically isolated in other soft tissue injuries. Patient demographic data and injury details were collected. Of the patients with adequate microbiology samples, 12% (6/50) grew clinically relevant bacteria resistant to amoxicillin and clavulanic acid. These included methicillin-resistant Staphylococcus aureus (8%, 4/50), Enterobacter cloacae (2%, 1/50) and an anaerobic sporing bacillus (2%, 1/50). Only one patient grew a true marine-specific bacteria, Photobacterium damselae, which was susceptible to amoxicillin and clavulanic acid. The authors concluded that amoxicillin and clavulanic acid is an adequate first-line antibiotic for fish spike injuries but that flucloxacillin may be more appropriate given most bacteria were from patients' own skin flora. The authors suggest that clinicians consider the presence of resistant marine-specific bacteria in cases where there is sepsis or inadequate response to initial therapy. © 2017 Royal Australasian College of Surgeons.

  3. Plasma needle treatment of bacteria known to cause infections of the soft tissue of the oral region and bones

    Science.gov (United States)

    Maletic, Dejan; Lazovic, Sasa; Puac, Nevena; Malovic, Gordana; Petrovic, Zoran Lj.; Miletic, Maja P.; Pavlica, Dusan B.; Jovanovic, Milena Z.; Milenkovic, Pavle

    2009-10-01

    Plasma needle can be used for non-contact disinfection of dental cavities and wounds, minimum-destructive precise treatment, as well as the removal of damaged tissue. The effect of bacterial deactivation is probably caused by reactive oxygen species while nitric oxide provided by plasma plays major role in many processes in the organism. Mass spectrometry was done to provide better insight into plasma-cell interactions. Our measurements were performed on a plasma needle that we originally used for the treatment of plant cells.Our research was done on species that are known to cause primary and secondary infections of the soft tissue of the oral region, as well as bones. The bacteria cultures used are bacterial reference culture species Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, Pseudomonas aeruginosa ATCC 27853, and Escherichia coli ATCC 25922. We investigated the effect of the plasma needle discharge on different concentration of bacteria using several exposure times and power transmitted to the plasma. It was found that excellent removal of this and other bacteria may be achieved by the plasma needle treatment.

  4. Diaper-Embedded Urinary Tract Infection Monitoring Sensor Module Powered by Urine-Activated Batteries.

    Science.gov (United States)

    Seo, Weeseong; Yu, Wuyang; Tan, Tianlin; Ziaie, Babak; Jung, Byunghoo

    2017-06-01

    Urinary tract infection (UTI) is one of the most common infections in humans. UTI is easily treatable using antibiotics if identified in early stage. However, without early identification and treatment, UTI can be a major source of serious complications in geriatric patients, in particular, those suffering from neurodegenerative diseases. Also, for infants who have difficulty in describing their symptoms, UTI may lead to serious development of the disease making early identification of UTI crucial. In this paper, we present a diaper-embedded, wireless, self-powered, and autonomous UTI monitoring sensor module that allows an early detection of UTI with minimal effort. The sensor module consists of a paper-based colorimetric nitrite sensor, urine-activated batteries, a boost dc-dc converter, a low-power sensor interface utilizing pulse width modulation, and a Bluetooth low energy module for wireless transmission. Experimental results show a better detection of nitrite, a surrogate of UTI, than that of conventional dipstick testing. The proposed sensor module achieves a sensitivity of 1.35 ms/(mg/L) and a detection limit of 4 mg/L for nitrite.

  5. Alendronate augments interleukin-1β release from macrophages infected with periodontal pathogenic bacteria through activation of caspase-1

    International Nuclear Information System (INIS)

    Deng Xue; Tamai, Riyoko; Endo, Yasuo; Kiyoura, Yusuke

    2009-01-01

    Nitrogen-containing bisphosphonates (NBPs) are anti-bone-resorptive drugs with inflammatory side effects that include osteomyelitis and osteonecrosis of the jaw. Oral bacteria have been considered to be a trigger for these NBP-associated jaw bone diseases. The present study examined the effects of alendronate (a typical NBP) and clodronate (a non-NBP) on the production of proinflammatory cytokines by macrophages infected with Porphyromonas gingivalis and Tannerella forsythia, which are important pathogens of periodontal diseases. Pretreatment with alendronate augmented IL-1β, but not TNFα, production by macrophages infected with P. gingivalis or T. forsythia. This augmentation of IL-1β production was inhibited by clodronate. Furthermore, caspase-1, a promoter of IL-1β production, was activated by treatment with alendronate, and caspase-1 inhibitor reduced the production of IL-1β induced by alendronate and P. gingivalis. These results suggest that NBPs augment periodontal pathogenic bacteria-induced IL-1β release via caspase-1 activation, and this phenomenon may contribute to the development of NBP-associated inflammatory side effects including jaw osteomyelitis. Co-treatment with clodronate may prevent and/or reduce these inflammatory effects induced by NBPs

  6. Alendronate augments interleukin-1{beta} release from macrophages infected with periodontal pathogenic bacteria through activation of caspase-1

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Deng; Tamai, Riyoko [Division of Oral Bacteriology, Department of Oral Medical Science, Ohu University School of Dentistry, 31-1 Misumido, Tomitamachi, Koriyama, Fukushima 963-8611 (Japan); Endo, Yasuo [Department of Molecular Regulation, Graduate School of Dentistry, Tohoku University, 4-1 Seiryo-machi, Aoba-ku, Sendai 980-8575 (Japan); Kiyoura, Yusuke [Division of Oral Bacteriology, Department of Oral Medical Science, Ohu University School of Dentistry, 31-1 Misumido, Tomitamachi, Koriyama, Fukushima 963-8611 (Japan)

    2009-02-15

    Nitrogen-containing bisphosphonates (NBPs) are anti-bone-resorptive drugs with inflammatory side effects that include osteomyelitis and osteonecrosis of the jaw. Oral bacteria have been considered to be a trigger for these NBP-associated jaw bone diseases. The present study examined the effects of alendronate (a typical NBP) and clodronate (a non-NBP) on the production of proinflammatory cytokines by macrophages infected with Porphyromonas gingivalis and Tannerella forsythia, which are important pathogens of periodontal diseases. Pretreatment with alendronate augmented IL-1{beta}, but not TNF{alpha}, production by macrophages infected with P. gingivalis or T. forsythia. This augmentation of IL-1{beta} production was inhibited by clodronate. Furthermore, caspase-1, a promoter of IL-1{beta} production, was activated by treatment with alendronate, and caspase-1 inhibitor reduced the production of IL-1{beta} induced by alendronate and P. gingivalis. These results suggest that NBPs augment periodontal pathogenic bacteria-induced IL-1{beta} release via caspase-1 activation, and this phenomenon may contribute to the development of NBP-associated inflammatory side effects including jaw osteomyelitis. Co-treatment with clodronate may prevent and/or reduce these inflammatory effects induced by NBPs.

  7. Modulation of epithelial sodium channel (ENaC expression in mouse lung infected with Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Radzioch Danuta

    2005-01-01

    Full Text Available Abstract Background The intratracheal instillation of Pseudomonas aeruginosa entrapped in agar beads in the mouse lung leads to chronic lung infection in susceptible mouse strains. As the infection generates a strong inflammatory response with some lung edema, we tested if it could modulate the expression of genes involved in lung liquid clearance, such as the α, β and γ subunits of the epithelial sodium channel (ENaC and the catalytic subunit of Na+-K+-ATPase. Methods Pseudomonas aeruginosa entrapped in agar beads were instilled in the lung of resistant (BalB/c and susceptible (DBA/2, C57BL/6 and A/J mouse strains. The mRNA expression of ENaC and Na+-K+-ATPase subunits was tested in the lung by Northern blot following a 3 hours to 14 days infection. Results The infection of the different mouse strains evoked regulation of α and β ENaC mRNA. Following Pseudomonas instillation, the expression of αENaC mRNA decreased to a median of 43% on days 3 and 7 after infection and was still decreased to a median of 45% 14 days after infection (p 1Na+-K+-ATPase mRNA, the catalytic subunit of the sodium pump, was recorded. The distinctive expression profiles of the three subunits were not different, between the susceptible and resistant mouse strains. Conclusions These results show that Pseudomonas infection, by modulating ENaC subunit expression, could influence edema formation and clearance in infected lungs.

  8. Abundance and Diversity of CO2-Assimilating Bacteria and Algae Within Red Agricultural Soils Are Modulated by Changing Management Practice.

    Science.gov (United States)

    Yuan, Hongzhao; Ge, Tida; Chen, Xiangbi; Liu, Shoulong; Zhu, Zhenke; Wu, Xiaohong; Wei, Wenxue; Whiteley, Andrew Steven; Wu, Jinshui

    2015-11-01

    Elucidating the biodiversity of CO(2)-assimilating bacterial and algal communities in soils is important for obtaining a mechanistic view of terrestrial carbon sinks operating at global scales. "Red" acidic soils (Orthic Acrisols) cover large geographic areas and are subject to a range of management practices, which may alter the balance between carbon dioxide production and assimilation through changes in microbial CO(2)-assimilating populations. Here, we determined the abundance and diversity of CO(2)-assimilating bacteria and algae in acidic soils using quantitative PCR and terminal restriction fragment length polymorphism (T-RFLP) of the cbbL gene, which encodes the key CO(2) assimilation enzyme (ribulose-1,5-bisphosphate carboxylase/oxygenase) in the Calvin cycle. Within the framework of a long-term experiment (Taoyuan Agro-ecosystem, subtropical China), paddy rice fields were converted in 1995 to four alternative land management regimes: natural forest (NF), paddy rice (PR), maize crops (CL), and tea plantations (TP). In 2012 (17 years after land use transformation), we collected and analyzed the soils from fields under the original and converted land management regimes. Our results indicated that fields under the PR soil management system harbored the greatest abundance of cbbL copies (4.33 × 10(8) copies g(-1) soil). More than a decade after converting PR soils to natural, rotation, and perennial management systems, a decline in both the diversity and abundance of cbbL-harboring bacteria and algae was recorded. The lowest abundance of bacteria (0.98 × 10(8) copies g(-1) soil) and algae (0.23 × 10(6) copies g(-1) soil) was observed for TP soils. When converting PR soil management to alternative management systems (i.e., NF, CL, and TP), soil edaphic factors (soil organic carbon and total nitrogen content) were the major determinants of bacterial autotrophic cbbL gene diversity. In contrast, soil phosphorus concentration was the major regulator

  9. Oral and dental infections with anaerobic bacteria: clinical features, predominant pathogens, and treatment.

    Science.gov (United States)

    Tanner, A; Stillman, N

    1993-06-01

    Microbial populations colonizing the teeth are a major source of pathogens responsible for oral and dental infections, including periodontal diseases, gingivitis, pericoronitis, endodontitis, peri-implantitis, and postextraction infections. Each entity has distinct clinical and microbial features. Bacterial species associated with oral infections include Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Bacteroides forsythus, Campylobacter rectus, Eubacterium species, Fusobacterium nucleatum, Eikenella corrodens, and Peptostreptococcus micros. Treponema pallidum-related spirochetes have been associated with acute necrotizing ulcerative gingivitis. Porphyromonas endodontalis appears to be specifically related to endodontic infections. Oral infections in medically compromised patients, including those with AIDS, are associated with similar species and are usually complicated by superinfection with enteric and Candida species. Isolation of species causing oral infections requires the collection of appropriate samples and the use of strictly anaerobic techniques. Rapid selective culture, immunofluorescence, and DNA probe methods have been developed for the identification of these oral species. The varied measures required in the management of oral and dental infections may include antimicrobial therapy. Accurate microbiological diagnosis, including antibiotic susceptibility testing, is indicated for cases that do not respond to therapy.

  10. Resiniferatoxin modulates the Th1 immune response and protects the host during intestinal nematode infection.

    Science.gov (United States)

    Muñoz-Carrillo, J L; Contreras-Cordero, J F; Muñoz-López, J L; Maldonado-Tapia, C H; Muñoz-Escobedo, J J; Moreno-García, M A

    2017-09-01

    In the early stage of the intestinal phase of Trichinella spiralis infection, the host triggers a Th1-type immune response with the aim of eliminating the parasite. However, this response damages the host which favours the survival of the parasite. In the search for novel pharmacological strategies that inhibit the Th1 immune response and assist the host against T. spiralis infection, a recent study showed that resiniferatoxin had anti-inflammatory activity contributed to the host in T. spiralis infection. In this study, we evaluated whether RTX modulates the host immune response through the inhibition of Th1 cytokines in the intestinal phase. In addition, it was determined whether the treatment with RTX affects the infectivity of T. spiralis-L1 and the development of the T. spiralis life cycle. Our results show that RTX decreased serum levels of IL-12, INF-γ, IL-1β, TNF-α and parasite burden on muscle tissue. It was observed that T. spiralis-L1 treated with RTX decreased their infectivity affecting the development of the T. spiralis life cycle in mouse. These results demonstrate that RTX is able to inhibit the production of Th1 cytokines, contributing to the defence against T. spiralis, which places it as a potential drug modulator of the immune response. © 2017 John Wiley & Sons Ltd.

  11. Ecological aspects of the antimicrobial resistence in bacteria of importance to humn infections

    OpenAIRE

    Meirelles-Pereira,Frederico de; Pereira,Angela de Meirelles Santos; Silva,Márcio Cataldo Gomes da; Gonçalves,Verônica Dias; Brum,Paulo Roberto; Castro,Almeida Ribeiro de; Pereira,Alexandre Adler; Esteves,Francisco de Assis; Pereira,José Augusto Adler

    2002-01-01

    In view of the intimate relationship of humans with coastal lagoons (used for recreation, tourism, water supply, etc.), the discharge of domestic effluents may lead to the establishment of routes of dissemination of pathogenic microorganisms, including microorganisms carrying genes for resistance to antimicrobials, through the surrounding human communities. The objective of the present investigation was to relate the presence of antimicrobial-resistant bacteria to the environmental characteri...

  12. [Cefazolin efficacy and antibiotic sensitivity against pathogenic bacteria in pediatric with acute upper urinary tract infection].

    Science.gov (United States)

    Fuke, Toshiya; Abe, Yoshifusa; Hoshino, Akihiro; Oto, Hideyasu; Sakai, Naho; Murayama, Junichiro; Yoshida, Koichiro; Itabashi, Kazuo

    2010-05-01

    Acute upper urinary tract infection may cause sepsis, especially in neonates and infants, mandating the choice of appropriate, effective antibacterials minimizing increasing bacterial resistance. Frequently prescribing broad-spectrum cephalosporinin is one such example. Different antibacterial therapies are initiated clinically due to treatment protocol differences among institutions, disease severity, etc. We studied the efficacy of cefazolin (CEZ), a first-generation cephalosporin, as first-line parenteral treatment in acute upper urinary tract infection. We found that 88.9% of microbial infections have indications for CEZ. CEZ efficacy is 91.3%, and 97.2% of urine cultures show negative results. Escherichia coli sensitivity to antibacterial agents is 90.9% of the minimal inhibitory concentration (MIC) pediatric therapy in acute upper urinary tract infection.

  13. Honey Bee as Alternative Medicine to Treat Eleven Multidrug-Resistant Bacteria Causing Urinary Tract Infection during Pregnancy.

    Science.gov (United States)

    Bouacha, Mabrouka; Ayed, Hayette; Grara, Nedjoud

    2018-04-13

    Medicinal benefits of honey bee have been recognized in the medical community since ancient times as a remedy for many diseases and infections. This study aimed to investigate the in vitro susceptibility of 11 multidrug-resistant bacterial strains, isolated from urinary tract infections of pregnant women, to six honey samples collected from different localities in the east of Algeria. The evaluation of the antibacterial activity was performed by the well method followed by the broth dilution method using two-fold dilutions of each honey sample ranging from 2.5 to 80% (w/v). The results obtained in this study revealed that all tested honeys exhibited potent antibacterial activity against the tested strains. The diameters of inhibition ranged from 19.67 to 53.33 mm, with minimum inhibitory concentrations (MICs) ranging from 2.5 to 40% (w/v) and minimum bactericidal concentration (MBCs) varied between 2.5 and 80% (w/v). Gram-positive bacteria were found to be more susceptible than Gram-negative bacteria with diameters ranging from 43.33 to 53.33 mm; MIC and MBC values ranged from 2.5 to 5% (w/v). The P.aeruginosa strain was found to be less susceptible than other strains with inhibitory diameters ranging from 19.67 to 27.33 mm; MICs ranged from 20 to 40% and MBCs ranged from 20 to 80% ( w/v ). This contribution has provided a broad overview of the antibacterial activity of Algerian honey and shown that honey bee has great potential for therapeutic use as an alternative therapy for urinary tract infection treatment which is safe and efficient during pregnancy.

  14. Honey Bee as Alternative Medicine to Treat Eleven Multidrug-Resistant Bacteria Causing Urinary Tract Infection during Pregnancy

    Directory of Open Access Journals (Sweden)

    Mabrouka Bouacha

    2018-04-01

    Full Text Available Medicinal benefits of honey bee have been recognized in the medical community since ancient times as a remedy for many diseases and infections. This study aimed to investigate the in vitro susceptibility of 11 multidrug-resistant bacterial strains, isolated from urinary tract infections of pregnant women, to six honey samples collected from different localities in the east of Algeria. The evaluation of the antibacterial activity was performed by the well method followed by the broth dilution method using two-fold dilutions of each honey sample ranging from 2.5 to 80% (w/v. The results obtained in this study revealed that all tested honeys exhibited potent antibacterial activity against the tested strains. The diameters of inhibition ranged from 19.67 to 53.33 mm, with minimum inhibitory concentrations (MICs ranging from 2.5 to 40% (w/v and minimum bactericidal concentration (MBCs varied between 2.5 and 80% (w/v. Gram-positive bacteria were found to be more susceptible than Gram-negative bacteria with diameters ranging from 43.33 to 53.33 mm; MIC and MBC values ranged from 2.5 to 5% (w/v. The P. aeruginosa strain was found to be less susceptible than other strains with inhibitory diameters ranging from 19.67 to 27.33 mm; MICs ranged from 20 to 40% and MBCs ranged from 20 to 80% (w/v. This contribution has provided a broad overview of the antibacterial activity of Algerian honey and shown that honey bee has great potential for therapeutic use as an alternative therapy for urinary tract infection treatment which is safe and efficient during pregnancy.

  15. Differential Change Patterns of Main Antimicrobial Peptide Genes During Infection of Entomopathogenic Nematodes and Their Symbiotic Bacteria.

    Science.gov (United States)

    Darsouei, Reyhaneh; Karimi, Javad; Ghadamyari, Mohammad; Hosseini, Mojtaba

    2017-08-01

    The expression of antimicrobial peptides (AMPs) as the main humoral defense reactions of insects during infection by entomopathogenic nematodes (EPNs) and their symbiont is addressed herein. Three AMPs, attacin, cecropin, and spodoptericin, were evaluated in the fifth instar larvae of Spodoptera exigua Hübner (beet armyworm) when challenged with Steinernema carpocapsae or Heterorhabditis bacteriophora. The results indicated that attacin was expressed to a greater extent than either cecropin or spodoptericin. While spodoptericin was expressed to a much lesser extent, this AMP was induced against Gram-positive bacteria, and thus not expressed after penetration of Xenorhabdus nematophila and Photorhabdus luminescens. Attacin and cecropin in the larvae treated with S. carpocapsae at 8 hr post-injection (PI) attained the maximum expression levels and were 138.42-fold and 65.84-fold greater than those of larvae infected with H. bacteriophora, respectively. Generally, the ability of H. bacteriophora to suppress attacin, cecropin, and spodoptericin was greater than that of S. carpocapsae. According to the results, the expression of AMPs by Sp. exigua larvae against S. carpocapsae was determined in the 4 statuses of monoxenic nematode, axenic nematode, live symbiotic bacterium, and dead symbiotic bacterium. The expression of attacin in larvae treated with a monoxenic nematode and live bacterium at 8 and 2 hr PI, respectively, were increased to the maximum amount. Live X. nematophila was the strongest agent for the suppression of attacin. The expression of cecropin against monoxenic nematodes and live symbiotic bacteria at 8 and 4 hr PI, respectively, reached the maximum amount while the expression levels of attacin and cecropin for axenic nematodes were lesser and stable. The results highlighted that the ability of P. luminescens in AMPs suppression was much more than X. nematophila. The results also showed that the effect of symbiotic bacterium in suppressing attacin and

  16. Sub-cellular mRNA localization modulates the regulation of gene expression by small RNAs in bacteria

    Science.gov (United States)

    Teimouri, Hamid; Korkmazhan, Elgin; Stavans, Joel; Levine, Erel

    2017-10-01

    Small non-coding RNAs can exert significant regulatory activity on gene expression in bacteria. In recent years, substantial progress has been made in understanding bacterial gene expression by sRNAs. However, recent findings that demonstrate that families of mRNAs show non-trivial sub-cellular distributions raise the question of how localization may affect the regulatory activity of sRNAs. Here we address this question within a simple mathematical model. We show that the non-uniform spatial distributions of mRNA can alter the threshold-linear response that characterizes sRNAs that act stoichiometrically, and modulate the hierarchy among targets co-regulated by the same sRNA. We also identify conditions where the sub-cellular organization of cofactors in the sRNA pathway can induce spatial heterogeneity on sRNA targets. Our results suggest that under certain conditions, interpretation and modeling of natural and synthetic gene regulatory circuits need to take into account the spatial organization of the transcripts of participating genes.

  17. Antibacterial activity of extracts from five medicinal plants and their formula against bacteria that cause chronic wound infection.

    Science.gov (United States)

    Temrangsee, Pornthep; Kondo, Sumalee; Itharat, Arunporn

    2011-12-01

    Chronic wound is caused by various factors such as chemotherapy, gene damage, treatment with steroids, diabetes mellitus, renal failure, blood pressure, infection and nutritional factors. One of the most common causes is bacterial infection. Antibacterial activity of several herbal plants has been reported. Thai medicinal plants which possess biological activities are potential to develop an alternative treatment of bacterial infection. To study efficiency of extracts from medicinal plants and their formula against bacteria that cause chronic wound infection. Extraction of Thai medicinal plants including Curcuma longa Linn, Rhinacanthus nasutus Linn, Garcinia mangostana Linn, Caesalpinia sappan Linn and Centellia asiatica Linn was performed by maceration with 95% ethanol and decoction followed by freeze dry. Formulation was conducted by varying the ratio of each components. Antibacterial activity were determined disk diffusion and broth dilution against Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, Acinetobacter baumanii, Escherichia coli and Klebsiella pneumoniae. Ethanolic extracts exhibited better antibacterial activity against tested strains than water extracts. Antibacterial activity of Caesalpinia sappan Linn. against S. aureus and MRSA showed the most effective with MIC value of 0.625 mg/ml. One of the five different formulas which contained two times proportion of C. sappan revealed that this formula was able to inhibit all tested strains with the MIC ranging between 0.156 mg/ml and 10 mg/ml. C. sappan is the most effective herbal plant. The formula with two times proportion of C. sappan is potentially best formula for development of medicinal product of chronic wound infection. The potential active compound of C. sappan is suggested for further investigation of antimicrobial activity and other biological properties.

  18. MicroRNA-146a Deficiency Protects against Listeria monocytogenes Infection by Modulating the Gut Microbiota

    Directory of Open Access Journals (Sweden)

    Chong-Tao Du

    2018-03-01

    Full Text Available The gut microbiota and microRNAs play important roles in the defense against infection. However, the role of miR-146a in L. monocytogenes infection and gut microbiota remains unclear. We tried to determine whether miR-146a controlled L. monocytogenes infection by regulating the gut microbiota. Wild-type and miR-146a-deficient mice or macrophages were used to characterize the impact of miR-146a on animal survival, cell death, bacterial clearance, and gut microbiota following L. monocytogenes challenge. We found that L. monocytogenes infection induced miR-146a expression both in vitro and in vivo. When compared to wild-type mice, miR-146a-deficient mice were more resistant to L. monocytogenes infection. MiR-146a deficiency in macrophages resulted in reduced invasion and intracellular survival of L. monocytogenes. High-throughput sequencing of 16S rRNA revealed that the gut microbiota composition differed between miR-146a-deficient and wild-type mice. Relative to wild-type mice, miR-146a-deficient mice had decreased levels of the Proteobacteria phylum, Prevotellaceae family, and Parasutterella genus, and significantly increased short-chain fatty acid producing bacteria, including the genera Alistipes, Blautia, Coprococcus_1, and Ruminococcus_1. Wild-type mice co-housed with miR-146a-deficient mice had increased resistance to L. monocytogenes, indicating that miR-146a deficiency guides the gut microbiota to alleviate infection. Together, these results suggest that miR-146a deficiency protects against L. monocytogenes infection by regulating the gut microbiota.

  19. MicroRNA-146a Deficiency Protects against Listeria monocytogenes Infection by Modulating the Gut Microbiota.

    Science.gov (United States)

    Du, Chong-Tao; Gao, Wei; Ma, Ke; Yu, Shui-Xing; Li, Na; Yan, Shi-Qing; Zhou, Feng-Hua; Liu, Zhen-Zhen; Chen, Wei; Lei, Lian-Cheng; Yang, Yong-Jun; Han, Wen-Yu

    2018-03-26

    The gut microbiota and microRNAs play important roles in the defense against infection. However, the role of miR-146a in L. monocytogenes infection and gut microbiota remains unclear. We tried to determine whether miR-146a controlled L. monocytogenes infection by regulating the gut microbiota. Wild-type and miR-146a-deficient mice or macrophages were used to characterize the impact of miR-146a on animal survival, cell death, bacterial clearance, and gut microbiota following L. monocytogenes challenge. We found that L. monocytogenes infection induced miR-146a expression both in vitro and in vivo. When compared to wild-type mice, miR-146a-deficient mice were more resistant to L. monocytogenes infection. MiR-146a deficiency in macrophages resulted in reduced invasion and intracellular survival of L. monocytogenes . High-throughput sequencing of 16S rRNA revealed that the gut microbiota composition differed between miR-146a-deficient and wild-type mice. Relative to wild-type mice, miR-146a-deficient mice had decreased levels of the Proteobacteria phylum, Prevotellaceae family, and Parasutterella genus, and significantly increased short-chain fatty acid producing bacteria, including the genera Alistipes , Blautia , Coprococcus_1, and Ruminococcus_1 . Wild-type mice co-housed with miR-146a-deficient mice had increased resistance to L. monocytogenes , indicating that miR-146a deficiency guides the gut microbiota to alleviate infection. Together, these results suggest that miR-146a deficiency protects against L. monocytogenes infection by regulating the gut microbiota.

  20. Biliary bacteria, antibiotic use, and wound infection in surgery of the gallbladder and common bile duct.

    Science.gov (United States)

    Lewis, R T; Goodall, R G; Marien, B; Park, M; Lloyd-Smith, W; Wiegand, F M

    1987-01-01

    That clinical risk groups predict postoperative infection in biliary operations has recently been challenged. To reevaluate the risk of infection, we studied 215 patients stratified by clinical risk factors. Of 100 patients having simple "low-risk" cholecystectomy, 11 had positive bile cultures (90% pure), and one with sterile bile got a staphylococcal wound infection (WI). Among 92 "high-risk" patients with acute cholecystitis, obstructive jaundice, or choledochal stones, 42 had positive bile cultures (44% pure, 12% anaerobes). One of 52 patients who received preoperative cefazolin got a staphylococcal WI, but ten of 40 patients without antibiotic therapy developed WIs, nine caused by organisms that also grew from the bile. Of 23 patients with obstructive cholangitis, 22 had positive bile cultures (88% mixed, 23% anaerobes). Despite antibiotic therapy, four developed WIs caused by these organisms. The concept of clinical risk factors is validated.

  1. TRPV1 Antagonism by Capsazepine Modulates Innate Immune Response in Mice Infected with Plasmodium berghei ANKA

    Directory of Open Access Journals (Sweden)

    Elizabeth S. Fernandes

    2014-01-01

    Full Text Available Thousands of people suffer from severe malaria every year. The innate immune response plays a determinant role in host’s defence to malaria. Transient receptor potential vanilloid 1 (TRPV1 modulates macrophage-mediated responses in sepsis, but its role in other pathogenic diseases has never been addressed. We investigated the effects of capsazepine, a TRPV1 antagonist, in malaria. C57BL/6 mice received 105 red blood cells infected with Plasmodium berghei ANKA intraperitoneally. Noninfected mice were used as controls. Capsazepine or vehicle was given intraperitoneally for 6 days. Mice were culled on day 7 after infection and blood and spleen cell phenotype and activation were evaluated. Capsazepine decreased circulating but not spleen F4/80+Ly6G+ cell numbers as well as activation of both F4/80+and F4/80+Ly6G+ cells in infected animals. In addition, capsazepine increased circulating but not spleen GR1+ and natural killer (NK population, without interfering with natural killer T (NKT cell numbers and blood NK and NKT activation. However, capsazepine diminished CD69 expression in spleen NKT but not NK cells. Infection increased lipid peroxidation and the release of TNFα and IFNγ, although capsazepine-treated group exhibited lower levels of lipid peroxidation and TNFα. Capsazepine treatment did not affect parasitaemia. Overall, TRPV1 antagonism modulates the innate immune response to malaria.

  2. Metabolome strategy against Edwardsiella tarda infection through glucose-enhanced metabolic modulation in tilapias.

    Science.gov (United States)

    Peng, Bo; Ma, Yan-Mei; Zhang, Jian-Ying; Li, Hui

    2015-08-01

    Edwardsiella tarda causes fish disease and great economic loss. However, metabolic strategy against the pathogen remains unexplored. In the present study, GC-MS based metabolomics was used to investigate the metabolic profile from tilapias infected by sublethal dose of E. tarda. The metabolic differences between the dying group and survival group allow the identification of key pathways and crucial metabolites during infections. More importantly, those metabolites may modulate the survival-related metabolome to enhance the anti-infective ability. Our data showed that tilapias generated two different strategies, survival-metabolome and death-metabolome, to encounter EIB202 infection, leading to differential outputs of the survival and dying. Glucose was the most crucial biomarker, which was upregulated and downregulated in the survival and dying groups, respectively. Exogenous glucose by injection or oral administration enhanced hosts' ability against EIB202 infection and increased the chances of survival. These findings highlight that host mounts the metabolic strategy to cope with bacterial infection, from which crucial biomarkers may be identified to enhance the metabolic strategy. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Dengue virus type 2 infections of Aedes aegypti are modulated by the mosquito's RNA interference pathway.

    Directory of Open Access Journals (Sweden)

    Irma Sánchez-Vargas

    2009-02-01

    Full Text Available A number of studies have shown that both innate and adaptive immune defense mechanisms greatly influence the course of human dengue virus (DENV infections, but little is known about the innate immune response of the mosquito vector Aedes aegypti to arbovirus infection. We present evidence here that a major component of the mosquito innate immune response, RNA interference (RNAi, is an important modulator of mosquito infections. The RNAi response is triggered by double-stranded RNA (dsRNA, which occurs in the cytoplasm as a result of positive-sense RNA virus infection, leading to production of small interfering RNAs (siRNAs. These siRNAs are instrumental in degradation of viral mRNA with sequence homology to the dsRNA trigger and thereby inhibition of virus replication. We show that although dengue virus type 2 (DENV2 infection of Ae. aegypti cultured cells and oral infection of adult mosquitoes generated dsRNA and production of DENV2-specific siRNAs, virus replication and release of infectious virus persisted, suggesting viral circumvention of RNAi. We also show that DENV2 does not completely evade RNAi, since impairing the pathway by silencing expression of dcr2, r2d2, or ago2, genes encoding important sensor and effector proteins in the RNAi pathway, increased virus replication in the vector and decreased the extrinsic incubation period required for virus transmission. Our findings indicate a major role for RNAi as a determinant of DENV transmission by Ae. aegypti.

  4. [Trend survey of ocular infections with bacteria at Toyama University Hospital over the past six years--from the standpoint of laboratory examination].

    Science.gov (United States)

    Kubota, Tomomi; Hayashi, Shirou; Niimi, Hideki; Kitajima, Isao

    2012-07-01

    Specimens of bacterial ocular infections are frequently received in the clinical laboratory. However, a comprehensive trend survey of ocular infections with bacteria is very rare. Our objective is to understand the current tendency of ocular infections with bacteria in patients at Toyama University Hospital from the standpoint of laboratory examination. We studied 263 cases of ocular infection with bacteria diagnosed at Toyama University Hospital from January 2006 to December 2011. 123 were male and 140 were female, with a mean age of 61.2(0-98) years. Specimens were subjected to direct microscopy and culture. Cultures were positive in 174(66.2%) patients. The most common bacterial isolate was Staphylococcus (28.1%), followed by Corynebacterium (19.3%), Streptococcus (9.3%), and Propionibacterium (8.6%). MRSA accounted for 18.8% of all S. aureus isolates, and has increased in recent years. The number of bacteria detected was larger in March, June, July, August, and October. Age distribution indicated that around 70% of bacterial isolates were detected from patients over 60 years old. The most common specimen of ocular infections with bacteria was eye discharge (detection rate; 87.8%), followed by corneal scraping(41%), aqueous humor (19%), and vitreous body (27%). Nearly 80% of bacterial isolates were detected from patients with keratitis, endophthalmitis, dacryocystitis, and conjunctivitis. As for the disease specific detection rate, endophthalmitis was very low (38.3%). The detection rate by years indicated that the way doctors pick up the specimens greatly affects the detection rate. Based on this survey, we need close cooperation with medical doctors concerning laboratory examination in ocular infection with bacteria, and we must improve the detection sensitivity of specimens from patients with endophthalmitis.

  5. Real Time Noninvasive Monitoring of Contaminating Bacteria in a Soft Tissue Implant Infection Model

    NARCIS (Netherlands)

    Engelsman, Anton F.; van der Mei, Henny C.; Francis, Kevin P.; Busscher, Henk J.; Ploeg, Rutger J.; van Dam, Gooitzen M.

    Infection is the main cause of biomaterials-related failure. A simple technique to test in-vivo new antimicrobial and/or nonadhesive implant coatings is unavailable. Current in vitro methods for studying bacterial adhesion and growth on biomaterial surfaces lack the influence of the host immune

  6. Engineered biomaterial and biophysical stimulation as combinatorial strategies to address prosthetic infection by pathogenic bacteria.

    Science.gov (United States)

    Boda, Sunil Kumar; Basu, Bikramjit

    2017-10-01

    A plethora of antimicrobial strategies are being developed to address prosthetic infection. The currently available methods for implant infection treatment include the use of antibiotics and revision surgery. Among the bacterial strains, Staphylococcus species pose significant challenges particularly, with regard to hospital acquired infections. In order to combat such life threatening infectious diseases, researchers have developed implantable biomaterials incorporating nanoparticles, antimicrobial reinforcements, surface coatings, slippery/non-adhesive and contact killing surfaces. This review discusses a few of the biomaterial and biophysical antimicrobial strategies, which are in the developmental stage and actively being pursued by several research groups. The clinical efficacy of biophysical stimulation methods such as ultrasound, electric and magnetic field treatments against prosthetic infection depends critically on the stimulation protocol and parameters of the treatment modality. A common thread among the three biophysical stimulation methods is the mechanism of bactericidal action, which is centered on biophysical rupture of bacterial membranes, the generation of reactive oxygen species (ROS) and bacterial membrane depolarization evoked by the interference of essential ion-transport. Although the extent of antimicrobial effect, normally achieved through biophysical stimulation protocol is insufficient to warrant therapeutic application, a combination of antibiotic/ROS inducing agents and biophysical stimulation methods can elicit a clinically relevant reduction in viable bacterial numbers. In this review, we present a detailed account of both the biomaterial and biophysical approaches for achieving maximum bacterial inactivation. Summarizing, the biophysical stimulation methods in a combinatorial manner with material based strategies can be a more potent solution to control bacterial infections. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B

  7. International Comparison of Causative Bacteria and Antimicrobial Susceptibilities of Urinary Tract Infections between Kobe, Japan, and Surabaya, Indonesia.

    Science.gov (United States)

    Kitagawa, Koichi; Shigemura, Katsumi; Yamamichi, Fukashi; Alimsardjono, Lindawati; Rahardjo, Dadik; Kuntaman, Kuntaman; Shirakawa, Toshiro; Fujisawa, Masato

    2018-01-23

    Variation by country in urinary tract infection (UTI)-causative bacteria is partly due to the differences in the use of antibiotics. We compared their frequencies and antibiotic susceptibilities in the treatment of patients with UTI from 2 cities, Kobe, Japan, and Surabaya, Indonesia. We retrospectively analyzed 1,804 urine samples collected from patients with UTI in 2014 (1,251 collected in 11 months at Kobe University Hospital in Kobe and 544 collected in 2 months at Dr. Soetomo Hospital in Surabaya). Surabaya data were divided into adult and pediatric patients because a substantial number of specimens from pediatric-patients had been collected. The results indicated that Escherichia coli was the most common uropathogen (24.1% in Kobe and 39.3% in Surabaya) and was significantly resistant to ampicillin and substantially to first- and third-generation cephalosporins in Surabaya adults but not in Kobe adults (p < 0.01). Enterococcus faecalis was often isolated in Kobe (14.0%), but not in Surabaya (5.3%). Klebsiella spp. were isolated at a higher rate in Surabaya pediatric patients (20.3%) than in Surabaya adults (13.6%) and Kobe adults (6.6%). The antibiotic susceptibilities of the isolates form Surabaya isolates tended to be lower than the ones from Kobe. Extended-spectrum β-lactamase-producing Gram-negative bacteria were detected at a significantly higher rate in Surabaya than in Kobe (p < 0.001). These results showed that the antimicrobial resistance patterns of UTI-causative bacteria are highly variable among 2 countries, and the continuous surveillance of trends in antibiotic resistance patterns of uropathogens is necessary for the future revision of antibiotic use.

  8. Urinary tract infection caused by community-acquired extended-spectrum β-lactamase-producing bacteria in infants.

    Science.gov (United States)

    Kim, Yun Hee; Yang, Eun Mi; Kim, Chan Jong

    Urinary tract infection (UTI) caused by resistant strains of bacteria is increasingly prevalent in children. The aim of this study was to investigate the clinical characteristics and risk factors for UTI caused by community-acquired extended-spectrum β-lactamase (CA-ESBL)-producing bacteria in infants. This was a retrospective study performed over 5 years in a single Korean center. Hospitalized infants with febrile UTI were enrolled and divided into two groups (CA-ESBL vs. CA non-ESBL UTI). The yearly prevalence was calculated. Baseline characteristics and clinical course such as fever duration, laboratory and radiological findings were compared between the two groups. Risk factors associated with the CA-ESBL UTI were investigated. Among the enrolled infants (n=185), 31 (17%) had CA-ESBL UTI. The yearly prevalence of ESBL of CA-ESBL UTI increased during the study (0% in 2010, 22.2% in 2015). Infants with CA-ESBL UTI had a longer duration of fever after initiating antibiotics (2.0±1.1 vs. 1.5±0.6 days, p=0.020). Cortical defects on renal scan and early treatment failure were more frequent in CA-ESBL (64.5 vs. 42.2%, p=0.023; 22.6 vs. 4.5%, p=0.001). A logistic regression analysis revealed that urinary tract abnormalities and previous UTI were independent risk factors for CA-EBSL UTI (odds ratio, 2.7; p=0.025; 10.3; p=0.022). The incidence of UTI caused by ESBL-producing bacteria has increased in Korean infants. Recognition of the clinical course and risk factors for ESLB-producing UTI may help to determine appropriate guidelines for its management. Copyright © 2016. Published by Elsevier Editora Ltda.

  9. The attribution of human infections with antimicrobial resistant Salmonella bacteria in Denmark to sources of animal origin

    DEFF Research Database (Denmark)

    Hald, Tine; Lo Fo Wong, Danilo M. A.; Aarestrup, Frank Møller

    2007-01-01

    Based on the Danish Salmonella surveillance in 2000-2001, we developed a mathematical model for quantifying the contribution of each major animal-food sources to human salmonellosis caused by antimicrobial resistant bacteria. Domestic food products accounted for 53.1% of all cases, mainly caused......, but infections with multidrug- and quinolone-resistant isolates were more commonly caused by imported food products and travelling, emphasizing the need for a global perspective on food safety and antimicrobial usage....... by table eggs (37.6%). A large proportion (19%) of cases were travel related, while 18% could not be associated with any source. Imported food products accounted for 9.5% of all cases; the most important source being imported chicken. Multidrug and quinolone resistance was rarely found in cases acquired...

  10. Infection dynamic of symbiotic bacteria in the pea aphid Acyrthosiphon pisum gut and host immune response at the early steps in the infection process.

    Directory of Open Access Journals (Sweden)

    François Renoz

    Full Text Available In addition to its obligatory symbiont Buchnera aphidicola, the pea aphid Acyrthosiphon pisum can harbor several facultative bacterial symbionts which can be mutualistic in the context of various ecological interactions. Belonging to a genus where many members have been described as pathogen in invertebrates, Serratia symbiotica is one of the most common facultative partners found in aphids. The recent discovery of strains able to grow outside their host allowed us to simulate environmental acquisition of symbiotic bacteria by aphids. Here, we performed an experiment to characterize the A. pisum response to the ingestion of the free-living S. symbiotica CWBI-2.3T in comparison to the ingestion of the pathogenic Serratia marcescens Db11 at the early steps in the infection process. We found that, while S. marcescens Db11 killed the aphids within a few days, S. symbiotica CWBI-2.3T did not affect host survival and colonized the whole digestive tract within a few days. Gene expression analysis of immune genes suggests that S. symbiotica CWBI-2.3T did not trigger an immune reaction, while S. marcescens Db11 did, and supports the hypothesis of a fine-tuning of the host immune response set-up for fighting pathogens while maintaining mutualistic partners. Our results also suggest that the lysosomal system and the JNK pathway are possibly involved in the regulation of invasive bacteria in aphids and that the activation of the JNK pathway is IMD-independent in the pea aphid.

  11. Infection dynamic of symbiotic bacteria in the pea aphid Acyrthosiphon pisum gut and host immune response at the early steps in the infection process.

    Science.gov (United States)

    Renoz, François; Noël, Christine; Errachid, Abdelmounaim; Foray, Vincent; Hance, Thierry

    2015-01-01

    In addition to its obligatory symbiont Buchnera aphidicola, the pea aphid Acyrthosiphon pisum can harbor several facultative bacterial symbionts which can be mutualistic in the context of various ecological interactions. Belonging to a genus where many members have been described as pathogen in invertebrates, Serratia symbiotica is one of the most common facultative partners found in aphids. The recent discovery of strains able to grow outside their host allowed us to simulate environmental acquisition of symbiotic bacteria by aphids. Here, we performed an experiment to characterize the A. pisum response to the ingestion of the free-living S. symbiotica CWBI-2.3T in comparison to the ingestion of the pathogenic Serratia marcescens Db11 at the early steps in the infection process. We found that, while S. marcescens Db11 killed the aphids within a few days, S. symbiotica CWBI-2.3T did not affect host survival and colonized the whole digestive tract within a few days. Gene expression analysis of immune genes suggests that S. symbiotica CWBI-2.3T did not trigger an immune reaction, while S. marcescens Db11 did, and supports the hypothesis of a fine-tuning of the host immune response set-up for fighting pathogens while maintaining mutualistic partners. Our results also suggest that the lysosomal system and the JNK pathway are possibly involved in the regulation of invasive bacteria in aphids and that the activation of the JNK pathway is IMD-independent in the pea aphid.

  12. Infection by chikungunya virus modulates the expression of several proteins in Aedes aegypti salivary glands

    Directory of Open Access Journals (Sweden)

    Tchankouo-Nguetcheu Stephane

    2012-11-01

    Full Text Available Abstract Background Arthropod-borne viral infections cause several emerging and resurging infectious diseases. Among the diseases caused by arboviruses, chikungunya is responsible for a high level of severe human disease worldwide. The salivary glands of mosquitoes are the last barrier before pathogen transmission. Methods We undertook a proteomic approach to characterize the key virus/vector interactions and host protein modifications that occur in the salivary glands that could be responsible for viral transmission by using quantitative two-dimensional electrophoresis. Results We defined the protein modulations in the salivary glands of Aedes aegypti that were triggered 3 and 5 days after an oral infection (3 and 5 DPI with chikungunya virus (CHIKV. Gel profile comparisons showed that CHIKV at 3 DPI modulated the level of 13 proteins, and at 5 DPI 20 proteins. The amount of 10 putatively secreted proteins was regulated at both time points. These proteins were implicated in blood-feeding or in immunity, but many have no known function. CHIKV also modulated the quantity of proteins involved in several metabolic pathways and in cell signalling. Conclusion Our study constitutes the first analysis of the protein response of Aedes aegypti salivary glands infected with CHIKV. We found that the differentially regulated proteins in response to viral infection include structural proteins and enzymes for several metabolic pathways. Some may favour virus survival, replication and transmission, suggesting a subversion of the insect cell metabolism by arboviruses. For example, proteins involved in blood-feeding such as the short D7, an adenosine deaminase and inosine-uridine preferring nucleoside hydrolase, may favour virus transmission by exerting an increased anti-inflammatory effect. This would allow the vector to bite without the bite being detected. Other proteins, like the anti-freeze protein, may support vector protection.

  13. Are there clinical signs and symptoms of infection to indicate the presence of multidrug-resistant bacteria in venous ulcers?

    Science.gov (United States)

    Dos Santos, Silvana de Lima Vieira; Martins, Marlene Andrade; do Prado, Marinésia Aparecida; Soriano, José Verdú; Bachion, Maria Márcia

    2017-12-01

    The selection of topical and systemic therapies for the treatment of venous ulcers with signs of infection is challenging and should be accompanied by specific precautionary measures to protect against cross-contamination in the presence of multidrug-resistant microorganisms. However, there are still no clinical indicators for this situation, and confirmation of resistant strains occurs through culture and sensitivity, which can take up to 14 days. During this period, protective measures may no longer be taken, contributing to the spread of these pathogens. This study aimed to analyze the relationship between clinical signs and symptoms of infection in venous ulcers and the presence of antimicrobial-resistant Staphylococcus aureus and/or Pseudomonas spp. A cross-sectional study was developed including 69 patients with 98 venous ulcers. Clinical observation protocol was applied to detect infection indicators established by the European Wound Management Association and microbiological analysis of samples of the lesions. Fisher's exact test and χ 2 were used for analyses (P 70%): discoloration of the opaque type and/or dark brick red and increased exudate volume; 31 (31.6%) ulcer samples showed positive culture for the bacteria studied. There was no relationship between signs and symptoms of infection and the presence of multidrug-resistant microorganisms. Taking into account the percentage of lesions with resistant strains, for safe care, contact precautionary measures should be implemented in the treatment rooms, in addition to standard precautions. Copyright © 2017 Society for Vascular Nursing, Inc. Published by Elsevier Inc. All rights reserved.

  14. Why sensitive bacteria are resistant to hospital infection control [version 2; referees: 2 approved

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    Esther van Kleef

    2017-11-01

    Full Text Available Background: Large reductions in the incidence of antibiotic-resistant strains of Staphylococcus aureus and Clostridium difficile have been observed in response to multifaceted hospital-based interventions. Reductions in antibiotic-sensitive strains have been smaller or non-existent. It has been argued that since infection control measures, such as hand hygiene, should affect resistant and sensitive strains equally, observed changes must have largely resulted from other factors, including changes in antibiotic use. We used a mathematical model to test the validity of this reasoning. Methods: We developed a mechanistic model of resistant and sensitive strains in a hospital and its catchment area. We assumed the resistant strain had a competitive advantage in the hospital and the sensitive strain an advantage in the community. We simulated a hospital hand hygiene intervention that directly affected resistant and sensitive strains equally. The annual incidence rate ratio (IRR associated with the intervention was calculated for hospital- and community-acquired infections of both strains. Results: For the resistant strain, there were large reductions in hospital-acquired infections (0.1 ≤ IRR ≤ 0.6 and smaller reductions in community-acquired infections (0.2 ≤ IRR ≤  0.9. These reductions increased in line with increasing importance of nosocomial transmission of the strain. For the sensitive strain, reductions in hospital acquisitions were much smaller (0.6 ≤ IRR ≤ 0.9, while communityacquisitions could increase or decrease (0.9 ≤ IRR ≤ 1.2. The greater the importance of the community environment for the transmission of the sensitive strain, the smaller the reductions. Conclusions: Counter-intuitively, infection control interventions, including hand hygiene, can have strikingly discordant effects on resistant and sensitive strains even though they target them equally, following differences in their adaptation to hospital and

  15. Anthrax lethal toxin disrupts intestinal barrier function and causes systemic infections with enteric bacteria.

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    Chen Sun

    Full Text Available A variety of intestinal pathogens have virulence factors that target mitogen activated protein kinase (MAPK signaling pathways, including Bacillus anthracis. Anthrax lethal toxin (LT has specific proteolytic activity against the upstream regulators of MAPKs, the MAPK kinases (MKKs. Using a murine model of intoxication, we show that LT causes the dose-dependent disruption of intestinal epithelial integrity, characterized by mucosal erosion, ulceration, and bleeding. This pathology correlates with an LT-dependent blockade of intestinal crypt cell proliferation, accompanied by marked apoptosis in the villus tips. C57BL/6J mice treated with intravenous LT nearly uniformly develop systemic infections with commensal enteric organisms within 72 hours of administration. LT-dependent intestinal pathology depends upon its proteolytic activity and is partially attenuated by co-administration of broad spectrum antibiotics, indicating that it is both a cause and an effect of infection. These findings indicate that targeting of MAPK signaling pathways by anthrax LT compromises the structural integrity of the mucosal layer, serving to undermine the effectiveness of the intestinal barrier. Combined with the well-described immunosuppressive effects of LT, this disruption of the intestinal barrier provides a potential mechanism for host invasion via the enteric route, a common portal of entry during the natural infection cycle of Bacillus anthracis.

  16. Predominant bacteria and patterns of antibiotic susceptibility in urinary tract infection in children with spina bifida.

    Science.gov (United States)

    Ortiz, Tara K; Velazquez, Nermarie; Ding, Laura; Routh, Jonathan C; Wiener, John S; Seed, Patrick C; Ross, Sherry S

    2018-04-20

    Urinary tract infection is more common in children with spina bifida (SB) than neurologically intact children, and Escherichiacoli is the most common urinary pathogen in the general pediatric population. Less is known of the pathogens responsible for urinary tract infections (UTI) in the pediatric SB population or their evolving antimicrobial resistance patterns. The goal of this study is to determine the epidemiology and antimicrobial resistance patterns of SB-associated urinary pathogens. Between January 1996 and August 2013, 231 patients aged 1 month to 18 years were identified with a diagnosis of SB-NB and at least one symptomatic urinary tract infection (UTI) event (Table). Two-hundred and thirty-one normally voiding children with a single symptomatic UTI were age-matched based on age at diagnosis of UTI at a 1:1 ratio. Chi-square tests and Generalized Estimating Equation analysis, controlling for clinicopathological factors, were performed to compare rates of pathogen-associations with UTI between groups and likelihood of UTI with multi-drug resistant (MDR) organisms. Children in the SB-NB group had a higher rate of non-E. coli UTI compared with controls (64% vs. 41%, p Children with SB-NB are more likely to have non-E. coli UTI, UTIs with MDR organisms, and urosepsis than the general pediatric population. Published by Elsevier Ltd.

  17. Virulence factors in Proteus bacteria from biofilm communities of catheter-associated urinary tract infections.

    Science.gov (United States)

    Hola, Veronika; Peroutkova, Tereza; Ruzicka, Filip

    2012-07-01

    More than 40% of nosocomial infections are those of the urinary tract, most of these occurring in catheterized patients. Bacterial colonization of the urinary tract and catheters results not only in infection, but also various complications, such as blockage of catheters with crystalline deposits of bacterial origin, generation of gravels and pyelonephritis. The diversity of the biofilm microbial community increases with duration of catheter emplacement. One of the most important pathogens in this regard is Proteus mirabilis. The aims of this study were to identify and assess particular virulence factors present in catheter-associated urinary tract infection (CAUTI) isolates, their correlation and linkages: three types of motility (swarming, swimming and twitching), the ability to swarm over urinary catheters, biofilm production in two types of media, urease production and adherence of bacterial cells to various types of urinary tract catheters. We examined 102 CAUTI isolates and 50 isolates taken from stool samples of healthy people. Among the microorganisms isolated from urinary catheters, significant differences were found in biofilm-forming ability and the swarming motility. In comparison with the control group, the microorganisms isolated from urinary catheters showed a wider spectrum of virulence factors. The virulence factors (twitching motility, swimming motility, swarming over various types of catheters and biofilm formation) were also more intensively expressed. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  18. Ultra-violet resonance Raman spectroscopy for the rapid discrimination of urinary tract infection bacteria.

    Science.gov (United States)

    Jarvis, Roger M; Goodacre, Royston

    2004-03-19

    The ability to identify pathogenic organisms rapidly provides significant benefits to clinicians; in particular, with respect to best prescription practices and tracking of recurrent infections. Conventional bioassays require 3-5 days before identification of an organism can be made, thus compromising the effectiveness with which patients can be treated for bacterial infections. We analysed 20 clinical isolates of urinary tract infections (UTI) by ultra-violet resonance Raman (UVRR) spectroscopy, utilising 244 nm excitation delivering approximately 0.1 mW laser power at the sample, with typical spectral collection times of 120 s. UVRR results in resonance-enhanced Raman signals for certain chromophoric segments of macromolecules, intensifying those selected bands above what would otherwise be observed for a normal Raman experiment. Utilising the whole-organism 'fingerprints' obtained by UVRR we were able to discriminate successfully between UTI pathogens using chemometric cluster analyses. This work demonstrates significant improvements in the speed with which spectra can be obtained by Raman spectroscopic techniques for the discrimination of clinical bacterial samples.

  19. [Rupture of venous bypass graft associated to infection of multiresistant bacteria].

    Science.gov (United States)

    Vidoedo, José C; Toledo, Timmy; Sampaio, Sérgio; Cerqueira, Alfredo; Vilaça, Isabel; Dias, Paulo; Carvalho, Joana; Meira, José; Mansilha, Armando; Paiva, José A; de Albuquerque, Roncon

    2006-01-01

    We report two cases of severe trauma of the upper limb requiring arterial revascularization. A brachio-brachial inverted saphenous bypass graft was done in both cases. Graft rupture attributed to local infection occurred at fourth post-operative week. Pseudomonas aeruginosa was isolated from the surgical wound in the first case and Acinetobacter baumanni in the second. The first case ended up with arm amputation mostly owing to extensive destruction of soft tissue, the patient being discharged home without any other sequel. In the second case the patient was successfully resuscitated after cardiopulmonary arrest, secondary to hemorrhagic shock. He underwent new brachio-brachial venous bypass graft avoiding the contaminated area. Irreversible ischemic signs plus growing overt infection led to arm amputation later on. This patient developed multi-organ failure and died by the fifth post-operative week. Acinetobacter baumannii and Pseudomonas aeruginosa are gram-negative bacilli widely present in hospital environment. Most of them are resistant to commonly used antibiotics. Their association with vascular conduit infections might have dreadful consequences as it happened in these cases.

  20. Specific Clinical Profile and Risk Factors for Mortality in General Surgery Patients with Infections by Multi-Drug-Resistant Gram-Negative Bacteria.

    Science.gov (United States)

    Rubio-Perez, Ines; Martin-Perez, Elena; Domingo-García, Diego; Garcia-Olmo, Damian

    2017-07-01

    The incidence of gram-negative multi-drug-resistant (MDR) infections is increasing worldwide. This study sought to determine the incidence, clinical profiles, risk factors, and mortality of these infections in general surgery patients. All general surgery patients with a clinical infection by gram-negative MDR bacteria were studied prospectively for a period of five years (2007-2011). Clinical, surgical, and microbiologic parameters were recorded, with a focus on the identification of risk factors for MDR infection and mortality. Incidence of MDR infections increased (5.6% to 15.2%) during the study period; 106 patients were included, 69.8% presented nosocomial infections. Mean age was 65 ± 15 years, 61% male. Extended-spectrum β-lactamases (ESBL) Escherichia coli was the most frequent MDR bacteria. Surgical site infections and abscesses were the most common culture locations. The patients presented multiple pre-admission risk factors and invasive measures during hospitalization. Mortality was 15%, and related to older age (odds ratio [OR] 1.07), malnutrition (OR 13.5), chronic digestive conditions (OR 4.7), chronic obstructive pulmonary disease (OR 3.9), and surgical re-intervention (OR 9.2). Multi-drug resistant infections in the surgical population are increasing. The most common clinical profile is a 65-year-old male, with previous comorbidities, who has undergone a surgical intervention, intensive care unit (ICU) admission, and invasive procedures and who has acquired the MDR infection in the nosocomial setting.

  1. Galectin-3 and Its Genetic Variation rs4644 Modulate Enterovirus 71 Infection.

    Directory of Open Access Journals (Sweden)

    Wen-Chan Huang

    Full Text Available Galectin-3, a chimeric type β-galactoside-binding protein, is known to modulate viral infection; however, its role in enterovirus 71 (EV71 infection has not been investigated. We generated galectin-3 null rhabdomyosarcoma (RD cells and evaluated whether EV71 infection would be affected. In galectin-3 null cells, the released and intracellular EV71 viral loads were suppressed after 24 h of infection, and cell death rates were significantly lower, while cell proliferation remained unaltered. In addition, RD cells expressing a nonsynonymous genetic variant of galectin-3, rs4644 (LGALS3 +191C/A, P64H, produced lower virus titers than those with wild-type galectin-3 (C allele. To clarify whether the in vitro viral load reduction correlates with clinical severity, we enrolled children with laboratory-confirmed EV71 infection. Since hyperglycemia is an indicator of severe EV71 infection in children, 152 of 401 enrolled children had glucose examinations at admission, and 59 subjects had serum glucose levels ≥ 150 mg/dL. In comparison to the rs4644 AA genotype (2.2 ± 0.06 log10 mg/dL, serum glucose levels during EV71 infection were higher in patients with CC (2.4 ± 0.17 log10 mg/dL, p = 0.03 and CA (2.4 ± 0.15 log10 mg/dL, p = 0.02 genotypes, respectively. These findings suggest that the rs4644 AA genotype of galectin-3 might exert a protective effect. In summary, galectin-3 affects EV71 replication in our cellular model and its variant, rs4644, is associated with hyperglycemia in the clinical setting. The underlying mechanism and its potential therapeutic application warrant further investigation.

  2. Staphylococcus aureus α-toxin modulates skin host response to viral infection.

    Science.gov (United States)

    Bin, Lianghua; Kim, Byung Eui; Brauweiler, Anne; Goleva, Elena; Streib, Joanne; Ji, Yinduo; Schlievert, Patrick M; Leung, Donald Y M

    2012-09-01

    Patients with atopic dermatitis (AD) with a history of eczema herpeticum have increased staphylococcal colonization and infections. However, whether Staphylococcus aureus alters the outcome of skin viral infection has not been determined. We investigated whether S aureus toxins modulated host response to herpes simplex virus (HSV) 1 and vaccinia virus (VV) infections in normal human keratinocytes (NHKs) and in murine infection models. NHKs were treated with S aureus toxins before incubation of viruses. BALB/c mice were inoculated with S aureus 2 days before VV scarification. Viral loads of HSV-1 and VV were evaluated by using real-time PCR, a viral plaque-forming assay, and immunofluorescence staining. Small interfering RNA duplexes were used to knockdown the gene expression of the cellular receptor of α-toxin, a disintegrin and metalloprotease 10 (ADAM10). ADAM10 protein and α-toxin heptamers were detected by using Western blot assays. We demonstrate that sublytic staphylococcal α-toxin increases viral loads of HSV-1 and VV in NHKs. Furthermore, we demonstrate in vivo that the VV load is significantly greater (P skin inoculated with an α-toxin-producing S aureus strain compared with murine skin inoculated with the isogenic α-toxin-deleted strain. The viral enhancing effect of α-toxin is mediated by ADAM10 and is associated with its pore-forming property. Moreover, we demonstrate that α-toxin promotes viral entry in NHKs. The current study introduces the novel concept that staphylococcal α-toxin promotes viral skin infection and provides a mechanism by which S aureus infection might predispose the host toward disseminated viral infections. Copyright © 2012 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

  3. Coxiella burnetii Nine Mile II proteins modulate gene expression of monocytic host cells during infection

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    Shaw Edward I

    2010-09-01

    Full Text Available Abstract Background Coxiella burnetii is an intracellular bacterial pathogen that causes acute and chronic disease in humans. Bacterial replication occurs within enlarged parasitophorous vacuoles (PV of eukaryotic cells, the biogenesis and maintenance of which is dependent on C. burnetii protein synthesis. These observations suggest that C. burnetii actively subverts host cell processes, however little is known about the cellular biology mechanisms manipulated by the pathogen during infection. Here, we examined host cell gene expression changes specifically induced by C. burnetii proteins during infection. Results We have identified 36 host cell genes that are specifically regulated when de novo C. burnetii protein synthesis occurs during infection using comparative microarray analysis. Two parallel sets of infected and uninfected THP-1 cells were grown for 48 h followed by the addition of chloramphenicol (CAM to 10 μg/ml in one set. Total RNA was harvested at 72 hpi from all conditions, and microarrays performed using Phalanx Human OneArray™ slides. A total of 784 (mock treated and 901 (CAM treated THP-1 genes were up or down regulated ≥2 fold in the C. burnetii infected vs. uninfected cell sets, respectively. Comparisons between the complementary data sets (using >0 fold, eliminated the common gene expression changes. A stringent comparison (≥2 fold between the separate microarrays revealed 36 host cell genes modulated by C. burnetii protein synthesis. Ontological analysis of these genes identified the innate immune response, cell death and proliferation, vesicle trafficking and development, lipid homeostasis, and cytoskeletal organization as predominant cellular functions modulated by C. burnetii protein synthesis. Conclusions Collectively, these data indicate that C. burnetii proteins actively regulate the expression of specific host cell genes and pathways. This is in addition to host cell genes that respond to the presence of the

  4. A host basal transcription factor is a key component for infection of rice by TALE-carrying bacteria.

    Science.gov (United States)

    Yuan, Meng; Ke, Yinggen; Huang, Renyan; Ma, Ling; Yang, Zeyu; Chu, Zhaohui; Xiao, Jinghua; Li, Xianghua; Wang, Shiping

    2016-07-29

    Transcription activator-like effectors (TALEs) are sequence-specific DNA binding proteins found in a range of plant pathogenic bacteria, where they play important roles in host-pathogen interactions. However, it has been unclear how TALEs, after they have been injected into the host cells, activate transcription of host genes required for infection success. Here, we show that the basal transcription factor IIA gamma subunit TFIIAγ5 from rice is a key component for infection by the TALE-carrying bacterium Xanthomonas oryzae pv. oryzae, the causal agent for bacterial blight. Direct interaction of several TALEs with TFIIAγ5 is required for activation of disease susceptibility genes. Conversely, reduced expression of the TFIIAγ5 host gene limits the induction of susceptibility genes and thus decreases bacterial blight symptoms. Suppression or mutation of TFIIAγ5 can also reduce bacterial streak, another devastating disease of rice caused by TALE-carrying X. oryzae pv. oryzicola. These results have important implications for formulating a widely applicable strategy with which to improve resistance of plants to TALE-carrying pathogens.

  5. Quorum quenching bacteria protect Macrobrachium rosenbergii larvae from Vibrio harveyi infection.

    Science.gov (United States)

    Nhan, D T; Cam, D T V; Wille, M; Defoirdt, T; Bossier, P; Sorgeloos, P

    2010-09-01

    In this study, we investigated the effect of N-acyl homoserine lactone-degrading bacterial enrichment cultures (ECs) on larviculture of the giant freshwater prawn Macrobrachium rosenbergii. The larval performance in terms of larval growth, larval survival, larval quality, duration of the larval rearing process and microflora levels in the rearing water as well as inside the prawn gut was investigated. The application of the EC bacteria was performed in two ways: by adding them directly into the larval rearing water and via enriched Artemia nauplii used for larval feeding. The results of the study demonstrated that both ECs that were tested had a similar positive effect on larval survival and larval quality, whereas they did not affect larval growth or the duration of the larval rearing process. Under normal hatchery conditions, the optimal EC densities were found to be 10(6) CFU ml(-1) for adding into the rearing water and 5 × 10(8) CFU ml(-1) for enrichment of Artemia nauplii used for feeding of the larvae. In the hatchery, the ECs can be grown on waste streams of Artemia hatching. Application of this kind of ECs could lead to a more sustainable aquaculture production, by replacing the use of antibiotics to control diseases. © 2010 The Authors. Journal compilation © 2010 The Society for Applied Microbiology.

  6. Ecological aspects of the antimicrobial resistence in bacteria of importance to humn infections

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    Meirelles-Pereira Frederico de

    2002-01-01

    Full Text Available In view of the intimate relationship of humans with coastal lagoons (used for recreation, tourism, water supply, etc., the discharge of domestic effluents may lead to the establishment of routes of dissemination of pathogenic microorganisms, including microorganisms carrying genes for resistance to antimicrobials, through the surrounding human communities. The objective of the present investigation was to relate the presence of antimicrobial-resistant bacteria to the environmental characteristics of three coastal lagoons, comparing the results with those from hospital sewage. Of the lagoons evaluated, two (Geribá and Imboassica receive domestic sewage discharge, and the other (Cabiúnas is still in a natural state. We isolated in a culture medium containing 32 ¼ µg/ml of Cephalothin, fecal coliforms (E. coli, non-fecal coliforms (Klebsiella, Enterobacter, Serratia, and Citrobacter, non-glucose-fermenting Gram-negative bacilli, and Aeromonas sp. In cultures from the hospital drain we found strains showing numerous markers for resistance to most of the 11 antimicrobials tested. On the other hand, in cultures from Cabiúnas and Imboassica lagoons, we found strains showing resistance only to antibiotics frequently observed in non-selective situations (considered as "common" markers. The capacity for dilution in the ecosystem, and salinity appeared related with the occurrence of multi-resistant bacterial strains. The intensity of recent fecal contamination was not shown to be associated with the numbers and types of markers found.

  7. Antibiotic resistance genes in anaerobic bacteria isolated from primary dental root canal infections.

    Science.gov (United States)

    Rôças, Isabela N; Siqueira, José F

    2012-12-01

    Fourty-one bacterial strains isolated from infected dental root canals and identified by 16S rRNA gene sequence were screened for the presence of 14 genes encoding resistance to beta-lactams, tetracycline and macrolides. Thirteen isolates (32%) were positive for at least one of the target antibiotic resistance genes. These strains carrying at least one antibiotic resistance gene belonged to 11 of the 26 (42%) infected root canals sampled. Two of these positive cases had two strains carrying resistance genes. Six out of 7 Fusobacterium strains harbored at least one of the target resistance genes. One Dialister invisus strain was positive for 3 resistance genes, and 4 other strains carried two of the target genes. Of the 6 antibiotic resistance genes detected in root canal strains, the most prevalent were blaTEM (17% of the strains), tetW (10%), and ermC (10%). Some as-yet-uncharacterized Fusobacterium and Prevotella isolates were positive for blaTEM, cfxA and tetM. Findings demonstrated that an unexpectedly large proportion of dental root canal isolates, including as-yet-uncharacterized strains previously regarded as uncultivated phylotypes, can carry antibiotic resistance genes. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Development of anti-infectives using phage display: biological agents against bacteria, viruses, and parasites.

    Science.gov (United States)

    Huang, Johnny X; Bishop-Hurley, Sharon L; Cooper, Matthew A

    2012-09-01

    The vast majority of anti-infective therapeutics on the market or in development are small molecules; however, there is now a nascent pipeline of biological agents in development. Until recently, phage display technologies were used mainly to produce monoclonal antibodies (MAbs) targeted against cancer or inflammatory disease targets. Patent disputes impeded broad use of these methods and contributed to the dearth of candidates in the clinic during the 1990s. Today, however, phage display is recognized as a powerful tool for selecting novel peptides and antibodies that can bind to a wide range of antigens, ranging from whole cells to proteins and lipid targets. In this review, we highlight research that exploits phage display technology as a means of discovering novel therapeutics against infectious diseases, with a focus on antimicrobial peptides and antibodies in clinical or preclinical development. We discuss the different strategies and methods used to derive, select, and develop anti-infectives from phage display libraries and then highlight case studies of drug candidates in the process of development and commercialization. Advances in screening, manufacturing, and humanization technologies now mean that phage display can make a significant contribution in the fight against clinically important pathogens.

  9. [Treatment-refractory-dental-extraction-associated pyothorax involving infection by 2 species of oral originated bacteria requires surgical debridement by video assisted thoracoscopic surgery (VATS)].

    Science.gov (United States)

    Rai, Kammei; Matsuo, Kiyoshi; Yonei, Toshiro; Sato, Toshio

    2008-09-01

    Cases of septic pulmonary embolism (SPE) diagnosed clinically by CT after dental extraction rarely include verification of bacteria from the local infection site. We report the case of a 70-year-old man without background disease suffering severe pyothrax after dental extraction. We detected two species of oral bacteria from his pleural effusion. Treatment was so difficult that it required surgical debridement by video assisted thoracoscopic surgery (VATS), even after the appropriate administration of antibiotics. According to the American Heart Association (AHA) prophylaxis guidelines for preventing infective endocarditis indicate that it is uncommon to prescribe antibiotics to patients without background disease after dental extraction. No appropriate Japanese guidelines exist considering the prevention of SPE causing severe pyothorax as in our case. The hematogenous spread of bacteria such as SPE caused by sepsis after tooth extraction thus requires more attended careful consideration in clinical practice if patients are to be properly protected against potentially serious complications.

  10. Clearance of Pseudomonas aeruginosa Foreign-Body Biofilm Infections through Reduction of the Cyclic Di-GMP Level in the Bacteria

    DEFF Research Database (Denmark)

    Christensen, Louise D.; van Gennip, Maria; Rybtke, Morten Theil

    2013-01-01

    Opportunistic pathogenic bacteria can engage in biofilm-based infections that evade immune responses and develop into chronic conditions. Because conventional antimicrobials cannot efficiently eradicate biofilms, there is an urgent need to develop alternative measures to combat biofilm infections....... It has recently been established that the secondary messenger cyclic diguanosine monophosphate (c-di-GMP) functions as a positive regulator of biofilm formation in several different bacteria. In the present study we investigated whether manipulation of the c-di-GMP level in bacteria potentially can...... be used for biofilm control in vivo. We constructed a Pseudomonas aeruginosa strain in which a reduction in the c-di-GMP level can be achieved via induction of the Escherichia coli YhjH c-di-GMP phosphodiesterase. Initial experiments showed that induction of yhjH expression led to dispersal...

  11. Resistance profiles to antimicrobial agents in bacteria isolated from acute endodontic infections: systematic review and meta-analysis.

    Science.gov (United States)

    Lang, Pauline M; Jacinto, Rogério C; Dal Pizzol, Tatiane S; Ferreira, Maria Beatriz C; Montagner, Francisco

    2016-11-01

    Infected root canal or acute apical abscess exudates can harbour several species, including Fusobacterium, Porphyromonas, Prevotella, Parvimonas, Streptococcus, Treponema, Olsenella and not-yet cultivable species. A systematic review and meta-analysis was performed to assess resistance rates to antimicrobial agents in clinical studies that isolated bacteria from acute endodontic infections. Electronic databases and the grey literature were searched up to May 2015. Clinical studies in humans evaluating the antimicrobial resistance of primary acute endodontic infection isolates were included. PRISMA guidelines were followed. A random-effect meta-analysis was employed. The outcome was described as the pooled resistance rates for each antimicrobial agent. Heterogeneity and sensitivity analyses were performed. Subgroup analyses were conducted based upon report or not of the use of antibiotics prior to sampling as an exclusion factor (subgroups A and B, respectively). Data from seven studies were extracted. Resistance rates for 15 different antimicrobial agents were evaluated (range, 3.5-40.0%). Lower resistance rates were observed for amoxicillin/clavulanic acid and amoxicillin; higher resistance rates were detected for tetracycline. Resistance rates varied according to previous use of an antimicrobial agent as demonstrated by the subgroup analyses. Heterogeneity was observed for the resistance profiles of penicillin G in subgroup A and for amoxicillin, clindamycin, metronidazole and tetracycline in subgroup B. Sensitivity analyses demonstrated that resistance rates changed for metronidazole, clindamycin, tetracycline and amoxicillin. These findings suggest that clinical isolates had low resistance to β-lactams. Further well-designed studies are needed to clarify whether the differences in susceptibility among the antimicrobial agents may influence clinical responses to treatment. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights

  12. Bryostatin modulates latent HIV-1 infection via PKC and AMPK signaling but inhibits acute infection in a receptor independent manner.

    Directory of Open Access Journals (Sweden)

    Rajeev Mehla

    2010-06-01

    Full Text Available HIV's ability to establish long-lived latent infection is mainly due to transcriptional silencing in resting memory T lymphocytes and other non dividing cells including monocytes. Despite an undetectable viral load in patients treated with potent antiretrovirals, current therapy is unable to purge the virus from these latent reservoirs. In order to broaden the inhibitory range and effectiveness of current antiretrovirals, the potential of bryostatin was investigated as an HIV inhibitor and latent activator. Bryostatin revealed antiviral activity against R5- and X4-tropic viruses in receptor independent and partly via transient decrease in CD4/CXCR4 expression. Further, bryostatin at low nanomolar concentrations robustly reactivated latent viral infection in monocytic and lymphocytic cells via activation of Protein Kinase C (PKC -alpha and -delta, because PKC inhibitors rottlerin and GF109203X abrogated the bryostatin effect. Bryostatin specifically modulated novel PKC (nPKC involving stress induced AMP Kinase (AMPK inasmuch as an inhibitor of AMPK, compound C partially ablated the viral reactivation effect. Above all, bryostatin was non-toxic in vitro and was unable to provoke T-cell activation. The dual role of bryostatin on HIV life cycle may be a beneficial adjunct to the treatment of HIV especially by purging latent virus from different cellular reservoirs such as brain and lymphoid organs.

  13. Triterpenoid herbal saponins enhance beneficial bacteria, decrease sulfate-reducing bacteria, modulate inflammatory intestinal microenvironment and exert cancer preventive effects in ApcMin/+ mice

    Science.gov (United States)

    Chen, Lei; Brar, Manreetpal S.; Leung, Frederick C. C.; Hsiao, W. L. Wendy

    2016-01-01

    Saponins derived from medicinal plants have raised considerable interest for their preventive roles in various diseases. Here, we investigated the impacts of triterpenoid saponins isolated from Gynostemma pentaphyllum (GpS) on gut microbiome, mucosal environment, and the preventive effect on tumor growth. Six-week old ApcMin/+ mice and their wild-type littermates were fed either with vehicle or GpS daily for the duration of 8 weeks. The fecal microbiome was analyzed by enterobacterial repetitive intergenic consensus (ERIC)-PCR and 16S rRNA gene pyrosequencing. Study showed that GpS treatment significantly reduced the number of intestinal polyps in a preventive mode. More importantly, GpS feeding strikingly reduced the sulfate-reducing bacteria lineage, which are known to produce hydrogen sulfide and contribute to damage the intestinal epithelium or even promote cancer progression. Meanwhile, GpS also boosted the beneficial microbes. In the gut barrier of the ApcMin/+ mice, GpS treatment increased Paneth and goblet cells, up-regulated E-cadherin and down-regulated N-cadherin. In addition, GpS decreased the pro-oncogenic β-catenin, p-Src and the p-STAT3. Furthermore, GpS might also improve the inflamed gut epithelium of the ApcMin/+ mice by upregulating the anti-inflammatory cytokine IL-4, while downregulating pro-inflammatory cytokines TNF-β, IL-1β and IL-18. Intriguingly, GpS markedly stimulated M2 and suppressed M1 macrophage markers, indicating that GpS altered mucosal cytokine profile in favor of the M1 to M2 macrophages switching, facilitating intestinal tissue repair. In conclusion, GpS might reverse the host's inflammatory phenotype by increasing beneficial bacteria, decreasing sulfate-reducing bacteria, and alleviating intestinal inflammatory gut environment, which might contribute to its cancer preventive effects. PMID:27121311

  14. Urinary Tract Infections Due to Catheterization and Drug Resistance Patterns of Isolated Bacteria

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    M. Mosavian

    2004-07-01

    Full Text Available UTI is the most common infection in all ages and urinary catheters especially long-term catheterization are important predisposing factors of UTI. Urinary catheters are used in different hospital wards as a complementary curative method for the patients who are undergone various surgical procedures, such as : cesarean, hysterectomy , laparotomy, etc and they who are unable to control their voided urine . 226 urine specimens were collected from 119 catheterized patients which had been hospitalized in seven wards of Razi and Golestan hospitals in Ahwas city . At least two urine specimens were collected from each patient , before and after the insertion of the catheter . All of the specimens were inoculated to suitable Media, after transportation to the Microbiology Lab . Isolated colonies were identified and their resistance patterns were determined by the standard disk diffusion method (Kirby –Bauer procedure to 8 different antibiotics. 38 cases (43.6% out of 87 patients showed Bacteriuria in the end of catheterization . They had no bacteriuria symptoms or sign before the catheterization. The most cases(28.9% of bacteriuria occured in 30-39 years group and the lowest cases (2.6 % of them occured in 60-69 years group. Out of 50 bacterial strains isolated from urine cultures , E.coil (with 17 cases was the highest (34% and Staphylococcus aureus , Klebsiella pneumoniae , Edwardsiella tarda , Enterobacter sakazakii (with 2% for each were the lowest cases. E.coli, Enterobacter and Kl. rhinoscleromatis , showed the most resistance to Ampicillin, Penicillin , Cephalexin , and the lowest rate to Nalidixic acid, Gentamicin and Nitrofurantoin . Staphylococcus epidermidis isolates ,also,showed the most resistance (100% to Penicillin and Ampicillin , and the lowest rate to Gentamicin (with 66.7%, Cotrimoxazol and Nitrofurantoin (with 50% .The results of this study suggested that catheterization , especially long- term catheterization causes the rise of

  15. PCR-based detection of resistance genes in anaerobic bacteria isolated from intra-abdominal infections.

    Science.gov (United States)

    Tran, Chau Minh; Tanaka, Kaori; Watanabe, Kunitomo

    2013-04-01

    Little information is available on the distribution of antimicrobial resistance genes in anaerobes in Japan. To understand the background of antimicrobial resistance in anaerobes involved in intra-abdominal infections, we investigated the distribution of eight antimicrobial resistance genes (cepA, cfiA, cfxA, ermF, ermB, mefA, tetQ, and nim) and a mutation in the gyrA gene in a total of 152 organisms (Bacteroides spp., Prevotella spp., Fusobacterium spp., Porphyromonas spp., Bilophila wadsworthia, Desulfovibrio desulfuricans, Veillonella spp., gram-positive cocci, and non-spore-forming gram-positive bacilli) isolated between 2003 and 2004 in Japan. The cepA gene was distributed primarily in Bacteroides fragilis. Gene cfxA was detected in about 9 % of the Bacteroides isolates and 75 % of the Prevotella spp. isolates and did not appear to contribute to cephamycin resistance. Two strains of B. fragilis contained the metallo-β-lactamase gene cfiA, but they did not produce the protein product. Gene tetQ was detected in about 81, 44, and 63 % of B. fragilis isolates, other Bacteroides spp., and Prevotella spp. isolates, respectively. The ermF gene was detected in 25, 13, 56, 64, and 16 % of Bacteroides spp., Prevotella spp., Fusobacterium spp., B. wadsworthia, and anaerobic cocci, respectively. Gene mefA was found in only 10 % of the B. fragilis strains and 3 % of the non-B. fragilis strains. Genes nim and ermB were not detected in any isolate. Substitution at position 82 (Ser to Phe) in gyrA was detected in B. fragilis isolates that were less susceptible or resistant to moxifloxacin. This study is the first report on the distribution of resistance genes in anaerobes isolated from intra-abdominal infections in Japan. We expect that the results might help in understanding the resistance mechanisms of specific anaerobes.

  16. Susceptibility to Lower Respiratory Infections in Childhood is Associated with Perturbation of the Cytokine Response to Pathogenic Airway Bacteria.

    Science.gov (United States)

    Vissing, Nadja Hawwa; Larsen, Jeppe Madura; Rasmussen, Morten Arendt; Chawes, Bo Lund Krogsgaard; Thysen, Anna Hammerich; Bønnelykke, Klaus; Brix, Susanne; Bisgaard, Hans

    2016-05-01

    Neonatal colonization of the airways with respiratory pathogens is associated with increased risk of lower respiratory infections (LRI) in early childhood. Therefore, we hypothesized that children developing LRI have an aberrant immune response to pathogenic bacteria in infancy. The objective was to characterize in vitro the early life systemic immune response to pathogenic bacteria and study the possible association with incidence of LRI during the first 3 years of life. The Copenhagen Prospective Studies on Asthma in Childhood2000 (COPSAC2000) is a clinical birth cohort study of 411 children born of mothers with asthma. LRI incidence was prospectively captured from 6-monthly planned visits and visits at acute respiratory episodes. The in vitro systemic immune response to Haemophilus influenzae, Moraxella catarrhalis and Streptococcus pneumoniae was characterized by the production of TNF-α, IFN-γ, IL-2, IL-5, IL-10, IL-13 and IL-17 in peripheral blood mononuclear cells isolated at age 6 months from 291 infants. Data were analyzed by Poisson regression against incidence of LRI in infancy. A multivariable model including all cytokine responses from the 3 different bacterial stimulations significantly identified children at risk of LRI (P = 0.006). The immune response pattern associated with LRI was characterized by perturbed production of several cytokines rather than production of one specific cytokine, and was independent of concurrent asthma. TNF-α and IL-5 were key drivers but did not explain the entire variation in LRI susceptibility. Children at risk of future LRI present a perturbed systemic immune response upon exposure to common airway pathogens in early life.

  17. Extended-spectrum β-lactamase-producing bacteria causing community-acquired urinary tract infections in children.

    Science.gov (United States)

    Megged, Orli

    2014-09-01

    Extended-spectrum β-lactamase (ESBL)-producing bacteria are infrequent pathogens of community-acquired (CA) urinary tract infections (UTIs) in children. The aim of this study was to assess the frequency of and identify risk factors for CA-UTIs due to ESBL-producing microorganisms (CA-ESBL-UTI). The medical records of all children diagnosed with CA-ESBL-UTI at our medical center between 2003 and 2013 were reviewed. Patients with non-ESBL-UTIs during the same period were included as controls. Eighty cases of CA-ESBL-UTI were identified. The incidence of ESBL-UTI increased from 2 to 3.8% during the study period. Compared to children with non-ESBL-UTI, those with ESBL were more likely to be of Arab descent, to have underlying medical conditions, to have received antibiotics in the month prior to the UTI and to have been previously hospitalized. The mean duration of hospitalization for patients with an ESBL-UTI was significantly longer than that for patients with a non-ESBL UTI (3.6 vs. 2 days; P = 0.01). In multivariate analysis, Arab ethnicity [odds ratio (OR) 6.1; 95 % confidence interval (CI) 2.7-13.6] and recent antibiotic treatment (OR 4.0; 95 % CI 1.6-10.4) were risk factors for CA-ESBL-UTI. The incidence of CA-ESBL-UTI is rising. The empiric treatment for suspected UTI in children who had been previously hospitalized and who had received antibiotics in the last month should cover ESBL-producing bacteria.

  18. High-throughput screening for compounds that modulate the cellular c-di-GMP level in bacteria

    DEFF Research Database (Denmark)

    Groizeleau, Julie; Andersen, Jens Bo; Givskov, Michael

    2017-01-01

    . The secondary messenger c-di-GMP is a positive regulator of biofilm formation in many clinically relevant bacteria, and it is assumed that drugs that lower the intracellular level of c-di-GMP will force biofilm bacteria into a more treatable planktonic lifestyle. We describe a protocol for high......-throughput screening of chemical libraries for compounds that lower the c-di-GMP level in bacteria, and potentially can serve as lead compounds in the development of novel biofilm dismantling drugs....

  19. A Possible Link between Infection with Burkholderia Bacteria and Systemic Lupus Erythematosus Based on Epitope Mimicry

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    2008-01-01

    Full Text Available We previously demonstrated that purified polyclonal and monoclonal anti-dsDNA antibodies bind a 15-mer peptide ASPVTARVLWKASHV in ELISA and Dot blot. This 15-mer peptide partial sequence ARVLWKASH shares similarity with burkholderia bacterial cytochrome B 561 partial sequence ARVLWRATH. In this study, we show that purified anti-dsDNA antibodies react with burkholderia fungorum bacterial cell lysates in Western blot. We used anti-dsDNA antibodies to make an anti-dsDNA antibodies affinity column and used this column to purify the burkholderia fungorum bacterial protein. Purified anti-dsDNA antibodies bind specifically to purified bacterial antigen and purified bacterial antigen blocked the anti-dsDNA antibodies binding to dsDNA antigen. Sera with anti-dsDNA antibodies bind specifically to purified bacterial antigen. We obtained protein partial sequence of RAGTDEGFG which is shared with burkholderia bacterial transcription regulator protein sequence. Sera with anti-dsDNA antibodies bind to RAGTDEGFG peptide better than control groups. These data support our hypothesis that the origin of anti-dsDNA antibodies in SLE may be associated with burkholderia bacterial infection.

  20. Kefir-isolated bacteria and yeasts inhibit Shigella flexneri invasion and modulate pro-inflammatory response on intestinal epithelial cells.

    Science.gov (United States)

    Bolla, P A; Abraham, A G; Pérez, P F; de Los Angeles Serradell, M

    2016-02-01

    The aim of this work was to evaluate the ability of a kefir-isolated microbial mixture containing three bacterial and two yeast strains (MM) to protect intestinal epithelial cells against Shigella flexneri invasion, as well as to analyse the effect on pro-inflammatory response elicited by this pathogen. A significant decrease in S. flexneri strain 72 invasion was observed on both HT-29 and Caco-2 cells pre-incubated with MM. Pre-incubation with the individual strains Saccharomyces cerevisiae CIDCA 8112 or Lactococcus lactis subsp. lactis CIDCA 8221 also reduced the internalisation of S. flexneri into HT-29 cells although in a lesser extent than MM. Interestingly, Lactobacillus plantarum CIDCA 83114 exerted a protective effect on the invasion of Caco-2 and HT-29 cells by S. flexneri. Regarding the pro-inflammatory response on HT-29 cells, S. flexneri infection induced a significant activation of the expression of interleukin 8 (IL-8), chemokine (C-C motif) ligand 20 (CCL20) and tumour necrosis factor alpha (TNF-α) encoding genes (P<0.05), whereas incubation of cells with MM did not induce the expression of any of the mediators assessed. Interestingly, pre-incubation of HT-29 monolayer with MM produced an inhibition of S. flexneri-induced IL-8, CCL20 and TNF-α mRNA expression. In order to gain insight on the effect of MM (or the individual strains) on this pro-inflammatory response, a series of experiments using a HT-29-NF-κB-hrGFP reporter system were performed. Pre-incubation of HT-29-NF-κB-hrGFP cells with MM significantly dampened Shigella-induced activation. Our results showed that the contribution of yeast strain Kluyveromyces marxianus CIDCA 8154 seems to be crucial in the observed effect. In conclusion, results presented in this study demonstrate that pre-treatment with a microbial mixture containing bacteria and yeasts isolated from kefir, resulted in inhibition of S. flexneri internalisation into human intestinal epithelial cells, along with the

  1. Immunohematopoietic modulation by oral β-1,3-glucan in mice infected with Listeria monocytogenes.

    Science.gov (United States)

    Torello, Cristiane O; de Souza Queiroz, Julia; Oliveira, Sueli C; Queiroz, Mary L S

    2010-12-01

    In this study we demonstrated that the oral administration of β-1,3-glucan (Imunoglucan®) protects mice from a lethal dose of Listeria monocytogenes (LM) when administered prophylactically for 10 days at the doses of 150 and 300 mg/kg, with survival rates up to 40%. These doses also prevented the myelosuppression and the splenomegaly caused by a sublethal infection with LM, due to increased numbers of granulocyte-macrophage progenitors (CFU-GM) in the bone marrow. Investigation of the production of colony-stimulating factors revealed an increased colony-stimulating activity (CSA) in the serum of infected mice pre-treated with Imunoglucan®. The treatment also restored the reduced ability of stromal cells to display myeloid progenitors in long-term bone marrow cultures (LTBMC) and up-regulated IL-6 and IL-1α production by these cells in the infected mice, which was consistent with higher number of non-adherent cells. Additional studies to investigate the levels of interferon-gamma (INF-γ) in the supernatant of splenocyte cultures demonstrated a further increase in the level of this cytokine in infected-treated mice, compared to infected controls. In all cases, no differences were observed between the responses of the two optimal biologically effective doses. In contrast, no significant changes were produced by the treatment with the 50mg/kg dose. In addition, no changes were observed in normal mice treated with the three doses used. All together our results suggest that orally given Imunoglucan® indirectly modulates immune activity and probably disengages Listeria induced suppression of these responses by inducing a higher reserve of myeloid progenitors in the bone marrow in consequence of biologically active cytokine release (CSFs, IL-1α, IL-6, and INF-γ). Copyright © 2010 Elsevier B.V. All rights reserved.

  2. Lactobacillus paracasei modulates the immune system of Galleria mellonella and protects against Candida albicans infection.

    Science.gov (United States)

    Rossoni, Rodnei Dennis; Fuchs, Beth Burgwyn; de Barros, Patrícia Pimentel; Velloso, Marisol Dos Santos; Jorge, Antonio Olavo Cardoso; Junqueira, Juliana Campos; Mylonakis, Eleftherios

    2017-01-01

    Probiotics have been described as a potential strategy to control opportunistic infections due to their ability to stimulate the immune system. Using the non-vertebrate model host Galleria mellonella, we evaluated whether clinical isolates of Lactobacillus spp. are able to provide protection against Candida albicans infection. Among different strains of Lactobacillus paracasei, Lactobacillus rhamnosus and Lactobacillus fermentum, we verified that L. paracasei 28.4 strain had the greatest ability to prolong the survival of larvae infected with a lethal dose of C. albicans. We found that the injection of 107 cells/larvae of L. paracasei into G. mellonella larvae infected by C. albicans increased the survival of these insects compared to the control group (P = 0.0001). After that, we investigated the immune mechanisms involved in the protection against C. albicans infection, evaluating the number of hemocytes and the gene expression of antifungal peptides. We found that L. paracasei increased the hemocyte quantity (2.38 x 106 cells/mL) in relation to the control group (1.29 x 106 cells/mL), indicating that this strain is capable of raising the number of circulating hemocytes into the G. mellonella hemolymph. Further, we found that L. paracasei 28.4 upregulated genes that encode the antifungal peptides galiomicin and gallerymicin. In relation to the control group, L. paracasei 28.4 increased gene expression of galiomicin by 6.67-fold and 17.29-fold for gallerymicin. Finally, we verified that the prophylactic provision of probiotic led to a significant reduction of the number of fungal cells in G. mellonella hemolymph. In conclusion, L. paracasei 28.4 can modulate the immune system of G. mellonella and protect against candidiasis.

  3. Lactobacillus paracasei modulates the immune system of Galleria mellonella and protects against Candida albicans infection

    Science.gov (United States)

    Rossoni, Rodnei Dennis; Fuchs, Beth Burgwyn; de Barros, Patrícia Pimentel; Velloso, Marisol dos Santos; Jorge, Antonio Olavo Cardoso; Junqueira, Juliana Campos; Mylonakis, Eleftherios

    2017-01-01

    Probiotics have been described as a potential strategy to control opportunistic infections due to their ability to stimulate the immune system. Using the non-vertebrate model host Galleria mellonella, we evaluated whether clinical isolates of Lactobacillus spp. are able to provide protection against Candida albicans infection. Among different strains of Lactobacillus paracasei, Lactobacillus rhamnosus and Lactobacillus fermentum, we verified that L. paracasei 28.4 strain had the greatest ability to prolong the survival of larvae infected with a lethal dose of C. albicans. We found that the injection of 107 cells/larvae of L. paracasei into G. mellonella larvae infected by C. albicans increased the survival of these insects compared to the control group (P = 0.0001). After that, we investigated the immune mechanisms involved in the protection against C. albicans infection, evaluating the number of hemocytes and the gene expression of antifungal peptides. We found that L. paracasei increased the hemocyte quantity (2.38 x 106 cells/mL) in relation to the control group (1.29 x 106 cells/mL), indicating that this strain is capable of raising the number of circulating hemocytes into the G. mellonella hemolymph. Further, we found that L. paracasei 28.4 upregulated genes that encode the antifungal peptides galiomicin and gallerymicin. In relation to the control group, L. paracasei 28.4 increased gene expression of galiomicin by 6.67-fold and 17.29-fold for gallerymicin. Finally, we verified that the prophylactic provision of probiotic led to a significant reduction of the number of fungal cells in G. mellonella hemolymph. In conclusion, L. paracasei 28.4 can modulate the immune system of G. mellonella and protect against candidiasis. PMID:28267809

  4. Study of antagonistic effects of Lactobacillus strains as probiotics on multi drug resistant (MDR) bacteria isolated from urinary tract infections (UTIs).

    Science.gov (United States)

    Naderi, Atiyeh; Kasra-Kermanshahi, Roha; Gharavi, Sara; Imani Fooladi, Abbas Ali; Abdollahpour Alitappeh, Meghdad; Saffarian, Parvaneh

    2014-03-01

    Urinary tract infection (UTI) caused by bacteria is one of the most frequent infections in human population. Inappropriate use of antibiotics, often leads to appearance of drug resistance in bacteria. However, use of probiotic bacteria has been suggested as a partial replacement. This study was aimed to assess the antagonistic effects of Lactobacillus standard strains against bacteria isolated from UTI infections. Among 600 samples; those with ≥10,000 cfu/ml were selected as UTI positive samples. Enterococcus sp., Klebsiella pneumoniae, Enterobacter sp., and Escherichia coli were found the most prevalent UTI causative agents. All isolates were screened for multi drug resistance and subjected to the antimicrobial effects of three Lactobacillus strains by using microplate technique and the MICs amounts were determined. In order to verify the origin of antibiotic resistance of isolates, plasmid curing using ethidium bromide and acridine orange was carried out. No antagonistic activity in Lactobacilli suspension was detected against test on Enterococcus and Enterobacter strains and K. pneumoniae, which were resistant to most antibiotics. However, an inhibitory effect was observed for E. coli which were resistant to 8-9 antibiotics. In addition, L. casei was determined to be the most effective probiotic. RESULTS from replica plating suggested one of the plasmids could be related to the gene responsible for ampicillin resistance. Treatment of E. coli with probiotic suspension was not effective on inhibition of the plasmid carrying hypothetical ampicillin resistant gene. Moreover, the plasmid profiles obtained from probiotic-treated isolates were identical to untreated isolates.

  5. Identification of Transcriptional Modules and Key Genes in Chickens Infected with Salmonella enterica Serovar Pullorum Using Integrated Coexpression Analyses

    Directory of Open Access Journals (Sweden)

    Bao-Hong Liu

    2017-01-01

    Full Text Available Salmonella enterica Pullorum is one of the leading causes of mortality in poultry. Understanding the molecular response in chickens in response to the infection by S. enterica is important in revealing the mechanisms of pathogenesis and disease progress. There have been studies on identifying genes associated with Salmonella infection by differential expression analysis, but the relationships among regulated genes have not been investigated. In this study, we employed weighted gene coexpression network analysis (WGCNA and differential coexpression analysis (DCEA to identify coexpression modules by exploring microarray data derived from chicken splenic tissues in response to the S. enterica infection. A total of 19 modules from 13,538 genes were associated with the Jak-STAT signaling pathway, the extracellular matrix, cytoskeleton organization, the regulation of the actin cytoskeleton, G-protein coupled receptor activity, Toll-like receptor signaling pathways, and immune system processes; among them, 14 differentially coexpressed modules (DCMs and 2,856 differentially coexpressed genes (DCGs were identified. The global expression of module genes between infected and uninfected chickens showed slight differences but considerable changes for global coexpression. Furthermore, DCGs were consistently linked to the hubs of the modules. These results will help prioritize candidate genes for future studies of Salmonella infection.

  6. A comparative evaluation of antibacterial effectiveness of sodium hypochlorite, Curcuma longa, and Camellia sinensis as irrigating solutions on isolated anaerobic bacteria from infected primary teeth

    Directory of Open Access Journals (Sweden)

    Neha Shashikant Dhariwal

    2016-01-01

    Full Text Available Context: In endodontics, most of the commercial intra-canal medicaments have cytotoxic reactions and because of their inability to eliminate bacteria from dentinal tubules, recent medicine has turned its attention to the usage of biologic medication prepared from natural plants. The literature to testify the efficacy of natural alternatives in primary teeth is meagre and its effects as irrigating solutions need to be evaluated. Aim: To evaluate the antibacterial effectiveness of sodium hypochlorite, ethanolic extracts of Curcuma longa (turmeric and Camellia sinensis (green tea as irrigating solutions against the anaerobic bacteria isolated from the root canals of infected primary teeth. Materials and Methods: Thirty patients were selected based on the selected inclusion and exclusion criteria. Preoperative radiographs were taken. Rubber dam isolation and working length estimation were done, following which thirty samples were taken from the root canals of infected primary teeth using sterile absorbent paper points and transferred to tubes containing thioglycolate transport medium. The bacteria were then isolated using standard microbiological protocols and were subjected to antibiotic sensitivity testing using the three test irrigants. Statistical Analysis: SPSS 18 software using Chi-square test was used for statistical analysis. Results: The most commonly isolated bacteria included Porphyromonas sp., Bacteroides fragilis, Peptostreptococcus, and Staphylococcus aureus. Sodium hypochlorite and C. longa (turmeric showed good antibacterial effect and were effective against most of the isolated bacteria. There was statistically significant difference in the antibacterial effect among the three tested groups (P < 0.001. The least effective was C. sinensis (green tea. Conclusion: The infected primary teeth almost always present with a polymicrobial structure with a wide variety of anaerobic bacteria. The chemo-mechanical preparation plays an important

  7. A comparative evaluation of antibacterial effectiveness of sodium hypochlorite, Curcuma longa, and Camellia sinensis as irrigating solutions on isolated anaerobic bacteria from infected primary teeth.

    Science.gov (United States)

    Dhariwal, Neha Shashikant; Hugar, Shivayogi M; Harakuni, Sheetal; Sogi, Suma; Assudani, Harsha G; Mistry, Laresh Naresh

    2016-01-01

    In endodontics, most of the commercial intra-canal medicaments have cytotoxic reactions and because of their inability to eliminate bacteria from dentinal tubules, recent medicine has turned its attention to the usage of biologic medication prepared from natural plants. The literature to testify the efficacy of natural alternatives in primary teeth is meagre and its effects as irrigating solutions need to be evaluated. To evaluate the antibacterial effectiveness of sodium hypochlorite, ethanolic extracts of Curcuma longa (turmeric) and Camellia sinensis (green tea) as irrigating solutions against the anaerobic bacteria isolated from the root canals of infected primary teeth. Thirty patients were selected based on the selected inclusion and exclusion criteria. Preoperative radiographs were taken. Rubber dam isolation and working length estimation were done, following which thirty samples were taken from the root canals of infected primary teeth using sterile absorbent paper points and transferred to tubes containing thioglycolate transport medium. The bacteria were then isolated using standard microbiological protocols and were subjected to antibiotic sensitivity testing using the three test irrigants. SPSS 18 software using Chi-square test was used for statistical analysis. The most commonly isolated bacteria included Porphyromonas sp., Bacteroides fragilis, Peptostreptococcus, and Staphylococcus aureus. Sodium hypochlorite and C. longa (turmeric) showed good antibacterial effect and were effective against most of the isolated bacteria. There was statistically significant difference in the antibacterial effect among the three tested groups (P < 0.001). The least effective was C. sinensis (green tea). The infected primary teeth almost always present with a polymicrobial structure with a wide variety of anaerobic bacteria. The chemo-mechanical preparation plays an important role in eradicating the population of predominant micro-organisms in treating these teeth with

  8. Population Density Modulates Drug Inhibition and Gives Rise to Potential Bistability of Treatment Outcomes for Bacterial Infections.

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    Jason Karslake

    2016-10-01

    Full Text Available The inoculum effect (IE is an increase in the minimum inhibitory concentration (MIC of an antibiotic as a function of the initial size of a microbial population. The IE has been observed in a wide range of bacteria, implying that antibiotic efficacy may depend on population density. Such density dependence could have dramatic effects on bacterial population dynamics and potential treatment strategies, but explicit measures of per capita growth as a function of density are generally not available. Instead, the IE measures MIC as a function of initial population size, and population density changes by many orders of magnitude on the timescale of the experiment. Therefore, the functional relationship between population density and antibiotic inhibition is generally not known, leaving many questions about the impact of the IE on different treatment strategies unanswered. To address these questions, here we directly measured real-time per capita growth of Enterococcus faecalis populations exposed to antibiotic at fixed population densities using multiplexed computer-automated culture devices. We show that density-dependent growth inhibition is pervasive for commonly used antibiotics, with some drugs showing increased inhibition and others decreased inhibition at high densities. For several drugs, the density dependence is mediated by changes in extracellular pH, a community-level phenomenon not previously linked with the IE. Using a simple mathematical model, we demonstrate how this density dependence can modulate population dynamics in constant drug environments. Then, we illustrate how time-dependent dosing strategies can mitigate the negative effects of density-dependence. Finally, we show that these density effects lead to bistable treatment outcomes for a wide range of antibiotic concentrations in a pharmacological model of antibiotic treatment. As a result, infections exceeding a critical density often survive otherwise effective treatments.

  9. Modulation of inflammation and pathology during dengue virus infection by p38 MAPK inhibitor SB203580.

    Science.gov (United States)

    Fu, Yilong; Yip, Andy; Seah, Peck Gee; Blasco, Francesca; Shi, Pei-Yong; Hervé, Maxime

    2014-10-01

    Dengue virus (DENV) infection could lead to dengue fever (DF), dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS). The disease outcome is controlled by both viral and host factors. Inflammation mediators from DENV-infected cells could contribute to increased vascular permeability, leading to severe DHF/DSS. Therefore, suppression of inflammation could be a potential therapeutic approach for treatment of dengue patients. In this context, p38 MAPK (mitogen-activated protein kinase) is a key enzyme that modulates the initiation of stress and inflammatory responses. Here we show that SB203580, a p38 MAPK inhibitor, suppressed the over production of DENV-induced pro-inflammatory mediators such as TNF-α, IL-8, and RANTES from human PBMCs, monocytic THP-1, and granulocyte KU812 cell lines. Oral administration of SB203580 in DENV-infected AG129 mice prevented hematocrit rise and lymphopenia, limited the development of inflammation and pathology (including intestine leakage), and significantly improved survival. These results, for the first time, have provided experimental evidence to imply that a short term inhibition of p38 MAPK may be beneficial to reduce disease symptoms in dengue patients. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. [Spectrum and drug sensitivity of pathogenic bacteria in children with nephrotic syndrome complicated by urinary tract infection: an analysis of 97 cases].

    Science.gov (United States)

    Song, Shao-Na; Zhang, Bi-Li; Wang, Wen-Hong; Zhang, Xuan

    2012-09-01

    To investigate the spectrum and drug sensitivity of pathogenic bacteria in children with nephrotic syndrome (NS) complicated by urinary tract infection (UTI). A retrospective analysis was performed on the spectrum and drug sensitivity of pathogenic bacteria in 97 children with NS complicated by UTI, who hospitalized from January to December, 2011. The incidence of UTI in children with NS was 36.5%. It was significantly more common in children with recurrent NS than in those with primary NS (44.0% vs 31.9%; Ppathogenic bacteria (50.5%), including Enterococcus faecium (29.4%) and Enterococcus faecalis (21.1%), followed by Gram-negative bacteria, such as Escherichia coli (15.6%) and Klebsiella pneumoniae (14.7%). Enterococcus was highly sensitive to nitrofurantoin, vacomycin and linezolid, but was highly resistant to tetracycline and moxifloxacin. More multi-resistant strains were detected in Enterococcus faecium than in Enterococcus faecalis (72% vs 17%; Pbacteria, 25% produced extended spectrum β-lactamases (ESBLs). ESBLs-producing bacteria had 100% sensitivity to imipenem, amikacin and piperacillin/tazobactam but were highly resistant to ampicillin, cefazolin and ceftriaxone. Children with recurrent NS are more susceptible to UTI than those with primary NS. Enterococcus is becoming major pathogenic bacteria for UTI in children with NS and has relatively high drug resistance, and most strains of Enterococcus faecium are multi-resistant.

  11. Exposure to ozone modulates human airway protease/antiprotease balance contributing to increased influenza A infection.

    Directory of Open Access Journals (Sweden)

    Matthew J Kesic

    Full Text Available Exposure to oxidant air pollution is associated with increased respiratory morbidities and susceptibility to infections. Ozone is a commonly encountered oxidant air pollutant, yet its effects on influenza infections in humans are not known. The greater Mexico City area was the primary site for the spring 2009 influenza A H1N1 pandemic, which also coincided with high levels of environmental ozone. Proteolytic cleavage of the viral membrane protein hemagglutinin (HA is essential for influenza virus infectivity. Recent studies suggest that HA cleavage might be cell-associated and facilitated by the type II transmembrane serine proteases (TTSPs human airway trypsin-like protease (HAT and transmembrane protease, serine 2 (TMPRSS2, whose activities are regulated by antiproteases, such as secretory leukocyte protease inhibitor (SLPI. Based on these observations, we sought to determine how acute exposure to ozone may modulate cellular protease/antiprotease expression and function, and to define their roles in a viral infection. We utilized our in vitro model of differentiated human nasal epithelial cells (NECs to determine the effects of ozone on influenza cleavage, entry, and replication. We show that ozone exposure disrupts the protease/antiprotease balance within the airway liquid. We also determined that functional forms of HAT, TMPRSS2, and SLPI are secreted from human airway epithelium, and acute exposure to ozone inversely alters their expression levels. We also show that addition of antioxidants significantly reduces virus replication through the induction of SLPI. In addition, we determined that ozone-induced cleavage of the viral HA protein is not cell-associated and that secreted endogenous proteases are sufficient to activate HA leading to a significant increase in viral replication. Our data indicate that pre-exposure to ozone disrupts the protease/antiprotease balance found in the human airway, leading to increased influenza susceptibility.

  12. Modulation of cytokine release by differentiated CACO-2 cells in a compartmentalized coculture model with mononuclear leucocytes and nonpathogenic bacteria

    DEFF Research Database (Denmark)

    Parlesak, Alexandr; Haller, D.; Brinz, S.

    2004-01-01

    To further investigate the interaction between human mononuclear leucocytes [peripheral blood mononuclear cells (PBMC)] and enterocytes, the effect of a confluent layer of differentiated CACO-2 cells on cytokine kinetics during challenge with bacteria in a compartmentalized coculture model...... cells when leucocytes were stimulated directly with bacteria. This suppression was not paralleled by changes in the production of IL-10, IL-6 and transforming growth factor (TGF)-beta. When the bacteria were applied apically to the CACO-2 cell layer, the production of TNF-alpha, IL-12, IL-1beta, IL-8......, IL-6, IL-10, TGF-beta and interferon-gamma was pronouncedly lower as compared to the bacterial stimulation of leucocytes beneath the CACO-2 cells. In the latter experiments, IL-6, IL-8 and TNF-alpha were the cytokines being mostly induced by apical addition of E. coli. Quantitative mRNA expression...

  13. A New Approach for the Discovery of Antibiotics by Targeting Non-Multiplying Bacteria: A Novel Topical Antibiotic for Staphylococcal Infections

    Science.gov (United States)

    Hu, Yanmin; Shamaei-Tousi, Alireza; Liu, Yingjun; Coates, Anthony

    2010-01-01

    In a clinical infection, multiplying and non-multiplying bacteria co-exist. Antibiotics kill multiplying bacteria, but they are very inefficient at killing non-multipliers which leads to slow or partial death of the total target population of microbes in an infected tissue. This prolongs the duration of therapy, increases the emergence of resistance and so contributes to the short life span of antibiotics after they reach the market. Targeting non-multiplying bacteria from the onset of an antibiotic development program is a new concept. This paper describes the proof of principle for this concept, which has resulted in the development of the first antibiotic using this approach. The antibiotic, called HT61, is a small quinolone-derived compound with a molecular mass of about 400 Daltons, and is active against non-multiplying bacteria, including methicillin sensitive and resistant, as well as Panton-Valentine leukocidin-carrying Staphylococcus aureus. It also kills mupirocin resistant MRSA. The mechanism of action of the drug is depolarisation of the cell membrane and destruction of the cell wall. The speed of kill is within two hours. In comparison to the conventional antibiotics, HT61 kills non-multiplying cells more effectively, 6 logs versus less than one log for major marketed antibiotics. HT61 kills methicillin sensitive and resistant S. aureus in the murine skin bacterial colonization and infection models. No resistant phenotype was produced during 50 serial cultures over a one year period. The antibiotic caused no adverse affects after application to the skin of minipigs. Targeting non-multiplying bacteria using this method should be able to yield many new classes of antibiotic. These antibiotics may be able to reduce the rate of emergence of resistance, shorten the duration of therapy, and reduce relapse rates. PMID:20676403

  14. Variability of cutaneous and nasal population levels between patients colonized and infected by multidrug-resistant bacteria in two Brazilian intensive care units.

    Science.gov (United States)

    Damaceno, Quésia; Nicoli, Jacques R; Oliveira, Adriana

    2015-01-01

    To compare cutaneous and nasal population levels between patients colonized and infected by multidrug-resistant organisms in two intensive care units. A prospective cohort study was performed in adult intensive care units of two hospitals in Belo Horizonte, Brazil (April 2012 to February 2013). Clinical and demographic data were first collected by reviewing patients' charts. Then, samples collected with nasal, groin, and perineum swabs were cultivated in selective media for 48 h at 37°C. After isolation, determination of antimicrobial susceptibility and biochemical identification were performed. A total of 53 cases of colonization were observed by the following bacteria in decreasing frequencies: imipenem-resistant Acinetobacter baumannii (50.9%), vancomycin-resistant Enterococcus faecalis (43.4%), extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (37.7%), imipenem-resistant Pseudomonas aeruginosa (32.1%), oxacillin-resistant Staphylococcus aureus (7.5%), and imipenem-resistant Klebsiella pneumoniae (5.7%). Among these colonization cases, 26 (49.0%) were followed by infection with bacteria phenotypically similar to those of the colonization. A relation between high population levels of colonization by most of the multidrug-resistant organisms at anatomical sites and a subsequent infection was observed. After colonization/infection, bacterial population levels decreased progressively and spontaneously until disappearance by day 45 in all the anatomical sites and for all the multidrug-resistant organisms. There was a correlation between high population levels of colonization by multidrug-resistant organisms at anatomical sites and a subsequent infection. Reduction in multidrug-resistant organism populations after colonization at anatomical sites could be a preventive measure to reduce evolution to infection as well as transmission of these bacteria between patients in intensive care unit.

  15. Relationship of periodontal infection to serum antibody levels to periodontopathic bacteria and inflammatory markers in periodontitis patients with coronary heart disease

    Science.gov (United States)

    Yamazaki, K; Honda, T; Domon, H; Okui, T; Kajita, K; Amanuma, R; Kudoh, C; Takashiba, S; Kokeguchi, S; Nishimura, F; Kodama, M; Aizawa, Y; Oda, H

    2007-01-01

    Several reports have demonstrated a possible association of periodontal infections with coronary heart disease (CHD) by elevated antibody titre to periodontopathic bacteria in CHD patients compared with non-diseased controls. Although each periodontopathic bacterium may vary in virulence for periodontitis and atherosclerosis, antibody response to multiple bacteria in CHD patients has not been understood fully. Therefore, serum levels of antibody to 12 periodontopathic bacteria together with other atherosclerotic risk markers were compared among 51 patients with CHD, 55 patients with moderate to severe chronic periodontitis and 37 healthy individuals. The antibody response was the most prevalent for Porphyromonas gingivalis, a major causative organism, in CHD as well as periodontitis patients. However, antibody positivity was different between CHD and periodontitis if the response was analysed for two different strains of P. gingivalis, namely FDC381 and Su63. While periodontitis patients were positive for both P. gingivalis FDC381 and Su63, a high frequency of antibody positivity for P. gingivalis Su63 but not for FDC381 was observed in CHD patients. The results indicate that the presence of particular periodontopathic bacteria with high virulence may affect atherogenesis. Identifying the virulence factors of P. gingivalis Su63 may gain insight into the new therapeutic modality for infection-induced deterioration of atherosclerosis. PMID:17645769

  16. Lactic-acid bacteria increase the survival of marine shrimp, Litopenaeus vannamei, after infection with Vibrio harveyi

    Directory of Open Access Journals (Sweden)

    Felipe do Nascimento Vieira

    2007-12-01

    Full Text Available This study evaluated the survival, post-larvae quality, and the population of bacteria in Litopenaeus vannamei after the addition of two strains of lactic-acid bacteria (2 and B6 experimentally infected by Vibrio harveyi. Fifteen hundred nauplii were distributed in 20 L capacity tanks with four replicates. The survival of control animals was lower (21% than that of animals fed with the strains B6 (50% and 2 (44%. Total bacterial population in the water and larvae, as well as of the Vibrio ssp. in water was not different among the treatments. No difference was observed in the population of Vibrio ssp. between the control larvae (5.5±0.5 log UFC/mL and that fed with strain 2 (5.4±0.1 log UFC/mL. Shrimp from control and fed with strain 2 showed significantly higher bacterial population than those fed with strain B6 (1.2±0.2 log UFC/mL. It was detected the lower load of Vibrio ssp. bacteria with potential of pathogenicity after feeding with strain B6.Moreover, these larvae showed more active behavior and low number of necrosis in relation to the control group and to that fed with strain 2.Este trabalho avaliou a adição de duas cepas de bactérias lácticas (2 e B6 na sobrevivência, qualidade de pós-larva e na população de bactérias na larvicultura de Litopenaeus vannamei experimentalmente infectado por Vibrio harveyi. Mil e quinhentos náuplios foram distribuídos em tanques de 20 L com quatro repetições. A sobrevivência dos animais controle foi menor (21% do que a dos alimentados com as cepas B6 (50% e 2 (44%. Sobrevivência de misis após desafio com V. harveyi foi maior em B6 do que nos outros tratamentos. A população total de bactérias na água e nas larvas, bem como de Vibrio ssp. na água não foi diferente entre os tratamentos. Não houve diferença, também, entre a população de Vibrio ssp. em larvas do grupo controle (5,5±0,5 log UFC/mL e larvas alimentadas com a cepa 2 (5,4±0,1 log UFC/mL. Camarões do grupo controle e

  17. Risk factors for infection and/or colonisation with extended-spectrum β-lactamase-producing bacteria in the neonatal intensive care unit: a meta-analysis.

    Science.gov (United States)

    Li, Xuan; Xu, Xuan; Yang, Xianxian; Luo, Mei; Liu, Pin; Su, Kewen; Qing, Ying; Chen, Shuai; Qiu, Jingfu; Li, Yingli

    2017-11-01

    Extended-spectrum β-lactamase (ESBL)-producing bacteria are an important cause of healthcare-associated infections in the neonatal intensive care unit (NICU). The aim of this meta-analysis was to identify risk factors associated with infection and/or colonisation with ESBL-producing bacteria in the NICU. Electronic databases were searched for relevant studies published from 1 January 2000 to 1 July 2016. The literature was screened and data were extracted according to the inclusion and exclusion criteria. The Z-test was used to calculate the pooled odds ratio (OR) of the risk factors. ORs and their 95% confidence intervals were used to determine the significance of the risk. A total of 14 studies, including 746 cases and 1257 controls, were identified. Thirteen risk factors were determined to be related to infection and/or colonisation with ESBL-producing bacteria in the NICU: birthweight [standardised mean difference (SMD) = 1.17]; gestational age (SMD = 1.36); Caesarean delivery (OR = 1.76); parenteral nutrition (OR = 7.51); length of stay in the NICU (SMD = 0.72); mechanical ventilation (OR = 4.8); central venous catheter use (OR = 2.85); continuous positive airway pressure (OR = 5.0); endotracheal intubation (OR = 2.82); malformations (OR = 2.89); previous antibiotic use (OR = 6.72); ampicillin/gentamicin (OR = 2.31); and cephalosporins (OR = 6.0). This study identified risk factors for infection and/or colonisation with ESBL-producing bacteria in the NICU, which may provide a theoretical basis for preventive measures and targeted interventions. Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  18. Clinical and economic outcomes associated with community-acquired intra-abdominal infections caused by extended spectrum beta-lactamase (ESBL) producing bacteria in China.

    Science.gov (United States)

    Hu, Bijie; Ye, Huifeng; Xu, Yingchun; Ni, Yuxing; Hu, Yunjian; Yu, Yunsong; Huang, Zhenfei; Ma, Larry

    2010-06-01

    To compare clinical and economic outcomes in patients with community-acquired intra-abdominal infection (IAI) due to extended spectrum beta-lactamase (ESBL) producing (ESBL-positive) bacteria versus non-ESBL-producing (ESBL-negative) bacteria in China. This was a retrospective chart review study of patients hospitalized with community-acquired IAI due to ESBL-positive or ESBL-negative infections caused by Escherichia coli or Klebsiella spp. Data were collected from six hospitals in China that participated in the Study for Monitoring Antibiotic Resistance Trends (SMART) during 2006-2007. Outcomes included clinical response at discharge and following first-line antibiotic, number of antibiotic agents and classes, duration of hospitalization, and overall hospitalization and intravenous antibiotic costs. Of the 85 patients included in the study, 32 (37.6%) had ESBL-positive and 53 (62.4%) had ESBL-negative infections; E. coli was responsible for 77.6% of infections. Infection resolved at discharge in 30 (93.8%) ESBL-positive and 48 (90.6%) ESBL-negative patients (P = NS). Fewer ESBL-positive patients achieved complete response following first-line antibiotics (56.3% versus 83.0%; P = 0.01). ESBL-positive patients required longer antibiotic treatment, more antibiotics, longer hospitalization (24.3 versus 14.6 days; 1.67-fold ratio; P = 0.001), and incurred higher hospitalization costs ( yen24,604 vs. yen13,788; $3604 vs. $2020; 1.78-fold ratio; P < 0.001). Patients with ESBL-positive infection had similar resolution rates at discharge compared to those with ESBL-negative infection, despite poorer first-line antibiotic response. However, ESBL-positive infection led to significantly greater hospitalization cost and intravenous antibiotic cost, and longer hospital stay.

  19. Infection processes of xylem-colonizing pathogenic bacteria: possible explanations for the scarcity of qualitative disease resistance genes against them in crops.

    Science.gov (United States)

    Bae, Chungyun; Han, Sang Wook; Song, Yu-Rim; Kim, Bo-Young; Lee, Hyung-Jin; Lee, Je-Min; Yeam, Inhwa; Heu, Sunggi; Oh, Chang-Sik

    2015-07-01

    Disease resistance against xylem-colonizing pathogenic bacteria in crops. Plant pathogenic bacteria cause destructive diseases in many commercially important crops. Among these bacteria, eight pathogens, Ralstonia solanacearum, Xanthomonas oryzae pv. oryzae, X. campestris pv. campestris, Erwinia amylovora, Pantoea stewartii subsp. stewartii, Clavibacter michiganensis subsp. michiganensis, Pseudomonas syringae pv. actinidiae, and Xylella fastidiosa, infect their host plants through different infection sites and paths and eventually colonize the xylem tissues of their host plants, resulting in wilting symptoms by blocking water flow or necrosis of xylem tissues. Noticeably, only a relatively small number of resistant cultivars in major crops against these vascular bacterial pathogens except X. oryzae pv. oryzae have been found or generated so far, although these pathogens threaten productivity of major crops. In this review, we summarize the lifestyles of major xylem-colonizing bacterial pathogens and then discuss the progress of current research on disease resistance controlled by qualitative disease resistance genes or quantitative trait loci against them. Finally, we propose infection processes of xylem-colonizing bacterial pathogens as one of possible reasons for why so few qualitative disease resistance genes against these pathogens have been developed or identified so far in crops.

  20. Nitric oxide modulates the immunological response of bovine PBMCs in an in vitro BRDc infection model.

    Science.gov (United States)

    Sheridan, Michael Peter; Regev-Shoshani, Gilly; Martins, James; Vimalanathan, Selvarani; Miller, Chris

    2016-12-01

    Bovine respiratory disease complex (BRDc) is a multi-factorial disease, involving both viral and bacterial pathogens, that negatively impacts the cattle feedlot industry. A nitric oxide releasing solution (NORS) has been developed and shown to have potential in the prevention of BRDc. This study investigated the underlying immunological mechanisms through which the nitroslyating agent NORS provides protection against the development of BRDc in susceptible cattle. An in vitro BRDc experimental model was designed using bovine peripheral blood mononuclear cells (PBMCs) which were infected with bovine herpesvirus 1 (BHV-1) and subsequently cultured with lipopolysaccharides (LPS) extracted from Mannheimia haemolytica bacteria. The cells were treated with NORS following viral infection to reflect the timing of administering the NORS treatment in feedlots during initial processing. An expression and protein analysis of key genes involved in the innate immune response was carried out. The BRDc model produced significant increases in gene expression (p<0.01) and protein release (p<0.05) of the proinflammatory cytokines IL-1β and TNF. Treatment with NORS reduced the protein levels of IL-1β (0.39-fold↓) (p<0.05) and TNF (0.48-fold↓) (p<0.01) in the BRDc experimental group when compared against the non-treatment BRDc controls. TLR4 expression, having been significantly reduced under the BRDc experimental conditions (0.33-fold↓) (p<0.05), increased significantly (0.76-fold↑) (p<0.05) following NORS treatment. This study provides evidence suggesting that NO may protect against the development of BRDc by limiting deleterious inflammation while simultaneously increasing TLR4 expression and enhancing the ability of the host to detect and respond to bacterial pathogens. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Pedilanthus tithymaloides Inhibits HSV Infection by Modulating NF-κB Signaling.

    Directory of Open Access Journals (Sweden)

    Durbadal Ojha

    Full Text Available Pedilanthus tithymaloides (PT, a widely used ethnomedicinal plant, has been employed to treat a number of skin conditions. To extend its utility and to fully exploit its medicinal potential, we have evaluated the in vitro antiviral activity of a methanolic extract of PT leaves and its isolated compounds against Herpes Simplex Virus type 2 (HSV-2. Bioactivity-guided studies revealed that the extract and one of its constituents, luteolin, had potent antiviral activity against wild-type and clinical isolates of HSV-2 (EC50 48.5-52.6 and 22.4-27.5 μg/ml, respectively, with nearly complete inhibition at 86.5-101.8 and 40.2-49.6 μg/ml, respectively. The inhibitory effect was significant (p<0.001 when the drug was added 2 h prior to infection, and was effective up to 4 h post-infection. As viral replication requires NF-κB activation, we examined whether the observed extract-induced inhibition of HSV-2 was related to NF-κB inhibition. Interestingly, we observed that treatment of HSV-2-infected cells with extract or luteolin suppressed NF-κB activation. Although NF-κB, JNK and MAPK activation was compromised during HSV replication, neither the extract nor luteolin affected HSV-2-induced JNK1/2 and MAPK activation. Moreover, the PT leaf extract and luteolin potently down-regulated the expression of tumor necrosis factor (TNF-α, Interleukin (IL-1β, IL-6, NO and iNOS and the production of gamma interferon (IFN-γ, which are directly involved in controlling the NF-κB signaling pathway. Thus, our results indicate that both PT leaf extract and luteolin modulate the NF-κB signaling pathway, resulting in the inhibition of HSV-2 replication.

  2. Parvovirus B19 infection modulates the levels of cytokines in the plasma of rheumatoid arthritis patients.

    Science.gov (United States)

    Naciute, Milda; Mieliauskaite, Diana; Rugiene, Rita; Maciunaite, Gabriele; Mauricas, Mykolas; Murovska, Modra; Girkontaite, Irute

    2017-08-01

    Parvovirus B19 (B19V) infection is associated with various autoimmune diseases. We investigated the levels of pro-inflammatory (IFNᵧ, TNFα, IL-2, IL-12) and anti-inflammatory (IL-4, IL-10) cytokines in the plasma of B19V DNA positive (B19 + ) and negative (B19 - ) rheumatoid arthritis (RA) patients in comparison with the control group (healthy persons). Blood samples were collected from 118 patients with RA and 49 healthy voluntaries. B19V sequence was determined in whole blood and cell-free plasma DNA by nested PCR. The levels of cytokines in the plasma and cell culture medium from Concanavalin A (ConA) or B19V VP1 protein stimulated PBMC were determined by ELISA. The levels of IL-4, IL-10, IL-12, IL-2 and TNFα were higher in plasma of RA patients in comparison with control persons. B19 + controls and RA patients had lower levels of IFNᵧ in comparison with B19 - controls and RA patients. Within RA patients the plasma levels of IFNᵧ were lower in patients with low RA disease activity or remission. Plasma level of IL-4 was increased and IL-10 level was decreased in B19 + RA patients in comparison with B19 - RA patients and did not differ between B19 + and B19 - controls. B19V infection did not affect plasma levels of IL-12, IL-2, and TNFα. ConA and B19 VP1 protein stimulated PBMC from RA patients produced less IFNᵧ than stimulated PBMC from the healthy controls. B19V infection could differently modulate the amount of cytokines in the plasma of healthy persons and RA patients. Decreased production of IFNᵧ and raised level of plasma IL-4 in RA patients could lower antiviral clearance. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. 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.

  4. Antibacterial Surface Design of Titanium-Based Biomaterials for Enhanced Bacteria-Killing and Cell-Assisting Functions Against Periprosthetic Joint Infection.

    Science.gov (United States)

    Wang, Jiaxing; Li, Jinhua; Qian, Shi; Guo, Geyong; Wang, Qiaojie; Tang, Jin; Shen, Hao; Liu, Xuanyong; Zhang, Xianlong; Chu, Paul K

    2016-05-04

    Periprosthetic joint infection (PJI) is one of the formidable and recalcitrant complications after orthopedic surgery, and inhibiting biofilm formation on the implant surface is considered crucial to prophylaxis of PJI. However, it has recently been demonstrated that free-floating biofilm-like aggregates in the local body fluid and bacterial colonization on the implant and peri-implant tissues can coexist and are involved in the pathogenesis of PJI. An effective surface with both contact-killing and release-killing antimicrobial capabilities can potentially abate these concerns and minimize PJI caused by adherent/planktonic bacteria. Herein, Ag nanoparticles (NPs) are embedded in titania (TiO2) nanotubes by anodic oxidation and plasma immersion ion implantation (PIII) to form a contact-killing surface. Vancomycin is then incorporated into the nanotubes by vacuum extraction and lyophilization to produce the release-killing effect. A novel clinical PJI model system involving both in vitro and in vivo use of methicillin-resistant Staphylococcus aureus (MRSA) ST239 is established to systematically evaluate the antibacterial properties of the hybrid surface against planktonic and sessile bacteria. The vancomycin-loaded and Ag-implanted TiO2 nanotubular surface exhibits excellent antimicrobial and antibiofilm effects against planktonic/adherent bacteria without appreciable silver ion release. The fibroblasts/bacteria cocultures reveal that the surface can help fibroblasts to combat bacteria. We first utilize the nanoarchitecture of implant surface as a bridge between the inorganic bactericide (Ag NPs) and organic antibacterial agent (vancomycin) to achieve total victory in the battle of PJI. The combination of contact-killing and release-killing together with cell-assisting function also provides a novel and effective strategy to mitigate bacterial infection and biofilm formation on biomaterials and has large potential in orthopedic applications.

  5. Penicillin kills Chlamydia following the fusion of bacteria with lysosomes and prevents genital inflammatory lesions in C. muridarum-infected mice.

    Directory of Open Access Journals (Sweden)

    Maud Dumoux

    Full Text Available The obligate intracellular bacterium Chlamydia exists as two distinct forms. Elementary bodies (EBs are infectious and extra-cellular, whereas reticulate bodies (RBs replicate within a specialized intracellular compartment termed an 'inclusion'. Alternative persistent intra-cellular forms can be induced in culture by diverse stimuli such as IFNγ or adenosine/EHNA. They do not grow or divide but revive upon withdrawal of the stimulus and are implicated in several widespread human diseases through ill-defined in vivo mechanisms. β-Lactam antibiotics have also been claimed to induce persistence in vitro. The present report shows that upon penicillin G (pG treatment, inclusions grow as fast as those in infected control cells. After removal of pG, Chlamydia do not revert to RBs. These effects are independent of host cell type, serovar, biovar and species of Chlamydia. Time-course experiments demonstrated that only RBs were susceptible to pG. pG-treated bacteria lost their control over host cell apoptotic pathways and no longer expressed pre-16S rRNA, in contrast to persistent bacteria induced with adenosine/EHNA. Confocal and live-video microscopy showed that bacteria within the inclusion fused with lysosomal compartments in pG-treated cells. That leads to recruitment of cathepsin D as early as 3 h post pG treatment, an event preceding bacterial death by several hours. These data demonstrate that pG treatment of cultured cells infected with Chlamydia results in the degradation of the bacteria. In addition we show that pG is significantly more efficient than doxycycline at preventing genital inflammatory lesions in C. muridarum-C57Bl/6 infected mice. These in vivo results support the physiological relevance of our findings and their potential therapeutic applications.

  6. A multidisciplinary intervention to reduce infections of ESBL- and AmpC-producing, gram-negative bacteria at a University Hospital

    DEFF Research Database (Denmark)

    Knudsen, Inge Jenny Dahl; Andersen, Stig Ejdrup

    2014-01-01

    aeruginosa and Enterococcus faecium infections increased (p'sproducing bacteria significantly decreased (p = 0.023). The unadjusted, all-cause 30-day mortality rates of K. pneumoniae and E. coli were unchanged over......In response to a considerable increase in the infections caused by ESBL/AmpC-producing Klebsiella pneumonia in 2008, a multidisciplinary intervention, with a main focus on antimicrobial stewardship, was carried out at one university hospital. Four other hospitals were used as controls. Stringent...... guidelines for antimicrobial treatment and prophylaxis were disseminated throughout the intervention hospital; cephalosporins were restricted for prophylaxis use only, fluoroquinolones for empiric use in septic shock only, and carbapenems were selected for penicillin-allergic patients, infections due to ESBL/AmpC-producing...

  7. Effect of experimental influenza A virus infection on isolation of Streptococcus pneumoniae and other aerobic bacteria from the oropharynges of allergic and nonallergic adult subjects.

    Science.gov (United States)

    Wadowsky, R M; Mietzner, S M; Skoner, D P; Doyle, W J; Fireman, P

    1995-04-01

    Intranasal challenge with both influenza A virus and Streptococcus pneumoniae promotes otitis media with S. pneumoniae in chinchillas. We investigated whether influenza A virus infection promotes oropharyngeal colonization with S. pneumoniae and other middle ear pathogens by selectively inhibiting commensal bacteria. On study day 0, 12 allergic and 15 nonallergic adult subjects were intranasally inoculated with influenza A/Kawasaki (H1N1) virus. Every subject was infected with the virus as demonstrated by nasal shedding or seroconversion. Average upper respiratory symptom scores and nasal secretion weights from the entire subject group were elevated between days 2 and 6 (acute phase) and were not significantly different between allergic and nonallergic subjects. S. pneumoniae was not isolated from any subject prior to the virus challenge but was isolated in heavy density from 4 (15%) subjects on day 6 (P = 0.055). Staphylococcus aureus was isolated more frequently from the nonallergic subjects than from the allergic subjects on days 2 (80 versus 25%, respectively) 4, (67 versus 17%, respectively), and 6 (73 versus 25%, respectively) (P < 0.05). The isolation rates of other middle ear pathogens were not significantly different before virus challenge and during the acute and resolution phases (days 27 to 30) of the experimental infection for the entire subject group or either the allergic or nonallergic subgroup. Densities and isolation rates of commensal bacteria from the entire subject group were similar throughout the observational period. These results suggest that the virus infection promoted S. pneumoniae colonization of the oropharynx and that nonallergic persons may be more vulnerable to colonization with S. aureus than allergic persons. The altered colonization rates were not attributed to inhibition of commensal bacteria.

  8. Antibiotic Resistance Pattern of Bacteria Causing Urinary Tract Infections in Children of Fasa During the years 2012 and 2014

    Directory of Open Access Journals (Sweden)

    alireza molazade

    2015-02-01

    Conclusion: Regarding the results, it is recommended to use Ciprofloxacin and Nitrofurantoin for outpatient treatment of UTI. Selecting proper antibiotics for UTI treatment should be on the basis of the local prevalence of pathogenic bacteria and antibiotic resistance pattern.

  9. Urinary tract infection caused by community‐acquired extended‐spectrum β‐lactamase‐producing bacteria in infants

    Directory of Open Access Journals (Sweden)

    Yun Hee Kim

    2017-05-01

    Conclusion: The incidence of UTI caused by ESBL‐producing bacteria has increased in Korean infants. Recognition of the clinical course and risk factors for ESLB‐producing UTI may help to determine appropriate guidelines for its management.

  10. Use of UV-irradiated bacteriophage T6 to kill extracellular bacteria in tissue culture infectivity assays

    International Nuclear Information System (INIS)

    Shaw, D.R.; Maurelli, A.T.; Goguen, J.D.; Straley, S.C.; Curtiss, R. III

    1983-01-01

    The authors have utilized 'lysis from without' mediated by UV-inactivated bacteriophage T6 to eliminate extracellular bacteria in experiments measuring the internalization, intracellular survival and replication of Yersinia pestis within mouse peritoneal macrophages and of Shigella flexneri within a human intestinal epithelial cell line. The technique described has the following characteristics: (a) bacterial killing is complete within 15 min at 37 0 C, with a >10 3 -fold reduction in colony-forming units (CFU); (b) bacteria within cultured mammalian cells are protected from killing by UV-inactivated T6; (c) the mammalian cells are not observably affected by exposure to UV-inactivated T6. This technique has several advantages over the use of antibiotics to eliminate extracellular bacteria and is potentially widely applicable in studies of the interactions between pathogenic bacteria and host phagocytic cells as well as other target tissues. (Auth.)

  11. Use of Predatory Prokaryotes to Control Drug-Resistant Bacteria and Microbial Biofilms Associated with Burn and Wound Infections

    Science.gov (United States)

    2011-06-01

    1 standard deviation. VOL. 77, 2011 PREDATION INHIBITION BY CARBOHYDRATES 2229 inhibiting effect (Fig. 3C). Since fermentation and catabolism of...between acidification of the media and predation. No inhibi- tion of predation or medium acidification was seen when non- fermentable sugar analogs were...ecology. When we eat yogurt and cheese, for example, we are eating bacteria.” Kadouri adds that the predator bacteria he is examining are among the many

  12. The Potential Application and Risks Associated With the Use of Predatory Bacteria as a Biocontrol Agent Against Wound Infections

    Science.gov (United States)

    2014-09-01

    antibiotics or phage therapy, the selective pressure of predation does not generate genetically stable resistant variants in the host. Since the...bacteria as a live antibiotic , examining the potential risk of predatory bacteria on non-microbial host is essential for the development of a safe...profile, and mice wound size. These experiments use either cyclophosphamide treated mice ( immunocompromised model) or normal mice. Treatment was done

  13. Surveillance of multidrug resistant suppurative infection causing bacteria in hospitalized patients in an Indian tertiary care hospital

    OpenAIRE

    Nabakishore Nayak; Rajesh K. Lenka; Rabindra N. Padhy

    2014-01-01

    Objective: To examine antibiograms of a cohort of suppurative bacteria isolated from wound-swabs from hospitalized patients of all economic groups of a typical Indian teaching hospital. Methods: In surveillance, antibiotic resistance patterns of 10 species of suppurative bacteria isolated from wound-swabs over a period of 24 months were recorded. Those were subjected to antibiotic sensitivity test, using 16 prescribed antibiotics of 5 different groups (3 aminoglycosides, 4 beta-lactams, 3 ...

  14. Diminazene aceturate (Berenil modulates the host cellular and inflammatory responses to Trypanosoma congolense infection.

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    Shiby Kuriakose

    Full Text Available BACKGROUND: Trypanosoma congolense are extracellular and intravascular blood parasites that cause debilitating acute or chronic disease in cattle and other domestic animals. Diminazene aceturate (Berenil has been widely used as a chemotherapeutic agent for trypanosomiasis in livestock since 1955. As in livestock, treatment of infected highly susceptible BALB/c mice with Berenil leads to rapid control of parasitemia and survival from an otherwise lethal infection. The molecular and biochemical mechanisms of action of Berenil are still not very well defined and its effect on the host immune system has remained relatively unstudied. Here, we investigated whether Berenil has, in addition to its trypanolytic effect, a modulatory effect on the host immune response to Trypanosoma congolense. METHODOLOGY/PRINCIPAL FINDINGS: BALB/c and C57BL/6 mice were infected intraperitoneally with T. congolense, treated with Berenil and the expression of CD25 and FoxP3 on splenic cells was assessed directly ex vivo. In addition, serum levels and spontaneous and LPS-induced production of pro-inflammatory cytokines by splenic and hepatic CD11b⁺ cells were determined by ELISA. Berenil treatment significantly reduced the percentages of CD25⁺ cells, a concomitant reduction in the percentage of regulatory (CD4⁺Foxp3⁺ T cells and a striking reduction in serum levels of disease exacerbating pro-inflammatory cytokines including IL-6, IL-12, TNF and IFN-γ. Furthermore, Berenil treatment significantly suppressed spontaneous and LPS-induced production of inflammatory cytokines by splenic and liver macrophages and significantly ameliorated LPS-induced septic shock and the associated cytokine storm. CONCLUSIONS/SIGNIFICANCE: Collectively, these results provide evidence that in addition to its direct trypanolytic effect, Berenil also modulates the host immune response to the parasite in a manner that dampen excessive immune activation and production of pathology

  15. [Nationwide sensitivity surveillance of ciprofloxacin and various parenteral antibiotics against bacteria isolated from patients with severe infections--the first Ciproxan IV special investigation in 2001].

    Science.gov (United States)

    Yamaguchi, Keizo; Ishii, Yoshikazu; Iinuma, Yoshitsugu; Yamanaka, Kiyoharu; Ichiyama, Satoshi; Watanabe, Naoki; Uehara, Nobuyuki; Kaku, Mitsuo; Kurokawa, Yukinori; Hayashi, Mutsumu; Hirakata, Yoichi

    2003-12-01

    The parenteral injection of ciprofloxacin (CPFX), a fluoroquinolone antimicrobial drug, was approved in September 2000 and a re-examination period of 6 years was set at that time. As a special investigation to apply for re-examination of this drug, it has been planned to conduct 3 nationwide surveillances during the re-examination period by collecting clinically isolated bacteria from patients with severe infections, to whom the drug was mainly indicated, and examining drug susceptibilities of the bacteria to various parenteral antimicrobial drugs including CPFX. This time, we determined the minimum inhibitory concentrations (MICs) of various parenteral antimicrobial drugs including CPFX against 1,220 strains isolated from patients with severe infections by the micro-liquid dilution method and compared susceptibilities of various clinically isolated bacteria to CPFX with those to other antimicrobial drugs. Gram-positive bacteria were less susceptible to CPFX than to carbapenems except 2 bacterial species, Enterococcus faecium and Enterococcus avium but susceptibilities of methicillin-susceptible Staphylococcus aureus (MSSA), Staphylococcus epidermidis and Enterococcus faecalis to CPFX were comparable to those to cefozopran. Susceptibility of Streptococcus pneumoniae to CPFX did not differ among ampicillin (ABPC)-susceptible Streptococcus pneumoniae (MIC of ABPC: MIC of ABPC: 0.25-2 micrograms/ml) and ABPC-resistant S. pneumoniae (MIC of ABPC: > or = 4 micrograms/ml) MIC90 of CPFX: 1 microgram/ml) and a decrease in the antimicrobial activity seen among cephem and carbapenem antimicrobial drugs against penicillin-intermediate strains was not noted with CPFX. Gram-negative bacteria were susceptible to CPFX similarly to carbapenems and the MIC90 values of CPFX were in the range from MIC90 was 2 micrograms/ml. CPFX also showed the lowest MIC90 value (0.5 microgram/ml) against beta-lactam-resistant P. aeruginosa among the drugs examined. When extended-spectrum beta

  16. A multidisciplinary intervention to reduce infections of ESBL- and AmpC-producing, gram-negative bacteria at a University Hospital.

    Directory of Open Access Journals (Sweden)

    Jenny Dahl Knudsen

    Full Text Available In response to a considerable increase in the infections caused by ESBL/AmpC-producing Klebsiella pneumonia in 2008, a multidisciplinary intervention, with a main focus on antimicrobial stewardship, was carried out at one university hospital. Four other hospitals were used as controls. Stringent guidelines for antimicrobial treatment and prophylaxis were disseminated throughout the intervention hospital; cephalosporins were restricted for prophylaxis use only, fluoroquinolones for empiric use in septic shock only, and carbapenems were selected for penicillin-allergic patients, infections due to ESBL/AmpC-producing and other resistant bacteria, in addition to their use in severe sepsis/septic shock. Piperacillin-tazobactam ± gentamicin was recommended for empiric treatments of most febrile conditions. The intervention also included education and guidance on infection control, as well as various other surveillances. Two year follow-up data on the incidence rates of patients with selected bacterial infections, outcomes, and antibiotic consumption were assessed, employing before-and-after analysis and segmented regression analysis of interrupted time series, using the other hospitals as controls. The intervention led to a sustained change in antimicrobial consumption, and the incidence of patients infected with ESBL-producing K. pneumoniae decreased significantly (p<0.001. The incidences of other hospital-associated infections also declined (p's<0.02, but piperacillin-tazobactam-resistant Pseudomonas aeruginosa and Enterococcus faecium infections increased (p's<0.033. In wards with high antimicrobial consumption, the patient gut carrier rate of ESBL-producing bacteria significantly decreased (p = 0.023. The unadjusted, all-cause 30-day mortality rates of K. pneumoniae and E. coli were unchanged over the four-year period, with similar results in all five hospitals. Although not statistically significant, the 30-day mortality rate of patients

  17. [The method and result analyses of pathogenic bacteria culture on chronic periprosthetic joint infection after total knee arthroplasty and total hip arthroplasty].

    Science.gov (United States)

    Ji, Baochao; Xu, Enjie; Cao, Li; Yang, Desheng; Xu, Boyong; Guo, Wentao; Aili, Rehei

    2015-02-01

    To analyze the results of pathogenic bacteria culture on chronic periprosthetic joint infection after total knee arthroplasty (TKA) and total hip arthroplasty (THA). The medical data of 23 patients with chronic periprosthetic joint infection after TKA or THA from September 2010 to March 2014 were reviewed. Fifteen cases of TKA and 8 cases of THA were included in this study. There were 12 male and 11 female patients with the mean age of 62 years (range from 32 to 79 years), and among them 9 patients with sinus. All patients discontinued antibiotic therapy for a minimum of 2 weeks before arthrocentesis, taking pathogenic bacteria culture and antimicrobial susceptibility test by using synovial fluid taken preoperatively and intraoperatively of revision. Common pathogenic bacteria culture and pathological biopsy were taken on tissues intraoperatively of revision. Culture-negative specimens were prolonged the period of incubation for 2 weeks. The overall culture-positive rate of all 23 patients for 1 week before revision was 30.4% (7/23), and the positive rate of culture-negative samples which prolonged for 2 weeks was 39.1% (9/23). The overall culture-positive rate of patients for 1 week intraoperatively of revision was 60.9% (14/23), and the positive rate of culture-negative samples which prolonged for 2 weeks was 82.6% (19/23). The incubation results of 7 cases (30.4%) preoperatively conformed to that of intraoperation. The culture-positive rate of pathogenic bacteria culture can be increased evidently by discontinuing antimicrobial therapy for a minimum of 2 weeks prior to the definite diagnosis.

  18. Lactobacillus delbrueckii subsp lactis CIDCA 133 modulates response of human epithelial and dendritic cells infected with Bacillus cereus.

    Science.gov (United States)

    Rolny, I S; Tiscornia, I; Racedo, S M; Pérez, P F; Bollati-Fogolín, M

    2016-11-30

    It is known that probiotic microorganisms are able to modulate pathogen virulence. This ability is strain dependent and involves multiple interactions between microorganisms and relevant host's cell populations. In the present work we focus on the effect of a potentially probiotic lactobacillus strain (Lactobacillus delbrueckii subsp. lactis CIDCA 133) in an in vitro model of Bacillus cereus infection. Our results showed that infection of intestinal epithelial HT-29 cells by B. cereus induces nuclear factor kappa B (NF-κB) pathway. Noteworthy, the presence of strain L. delbrueckii subsp.lactis CIDCA 133 increases stimulation. However, B. cereus-induced interleukin (IL)-8 production by epithelial cells is partially abrogated by L. delbrueckii subsp. lactis CIDCA 133. These findings suggest that signalling pathways other than that of NF-κB are involved. In a co-culture system (HT-29 and monocyte-derived dendritic cells), B. cereus was able to translocate from the epithelial (upper) to the dendritic cell compartment (lower). This translocation was partially abrogated by the presence of lactobacilli in the upper compartment. In addition, infection of epithelial cells in the co-culture model, led to an increase in the expression of CD86 by dendritic cells. This effect could not be modified in the presence of lactobacilli. Interestingly, infection of enterocytes with B. cereus triggers production of proinflammatory cytokines by dendritic cells (IL-8, IL-6 and tumour necrosis factor alpha (TNF-α)). The production of TNF-α (a protective cytokine in B. cereus infections) by dendritic cells was increased in the presence of lactobacilli. The present work demonstrates for the first time the effect of L. delbrueckii subsp. lactis CIDCA 133, a potentially probiotic strain, in an in vitro model of B. cereus infection. The presence of the probiotic strain modulates cell response both in infected epithelial and dendritic cells thus suggesting a possible beneficial effect of

  19. Host immune responses to a viral immune modulating protein: immunogenicity of viral interleukin-10 in rhesus cytomegalovirus-infected rhesus macaques.

    Directory of Open Access Journals (Sweden)

    Meghan K Eberhardt

    Full Text Available Considerable evidence has accumulated that multiple viruses, bacteria, and protozoa manipulate interleukin-10 (IL-10-mediated signaling through the IL-10 receptor (IL-10R in ways that could enable establishment of a persistent microbial infection. This suggests that inhibition of pathogen targeting of IL-10/IL-10R signaling could prevent microbial persistence. Human cytomegalovirus (HCMV and rhesus cytomegalovirus (RhCMV express a viral interleukin-10 (cmvIL-10 and rhcmvIL-10, respectively with comparable immune modulating properties in vitro to that of their host's cellular IL-10 (cIL-10. A prior study noted that rhcmvIL-10 alters innate and adaptive immunity to RhCMV in vivo, consistent with a central role for rhcmvIL-10 during acute virus-host interactions. Since cmvIL-10 and rhcmvIL-10 are extremely divergent from the cIL-10 of their respective hosts, vaccine-mediated neutralization of their function could inhibit establishment of viral persistence without inhibition of cIL-10.As a prelude to evaluating cmvIL-10-based vaccines in humans, the rhesus macaque model of HCMV was used to interrogate peripheral and mucosal immune responses to rhcmvIL-10 in RhCMV-infected animals. ELISA were used to detect rhcmvIL-10-binding antibodies in plasma and saliva, and an IL-12-based bioassay was used to quantify plasma antibodies that neutralized rhcmvIL-10 function. rhcmvIL-10 is highly immunogenic during RhCMV infection, stimulating high avidity rhcmvIL-10-binding antibodies in the plasma of all infected animals. Most infected animals also exhibited plasma antibodies that partially neutralized rhcmvIL-10 function but did not cross-neutralize the function of rhesus cIL-10. Notably, minimally detectable rhcmvIL-10-binding antibodies were detected in saliva.This study demonstrates that rhcmvIL-10, as a surrogate for cmvIL-10, is a viable vaccine candidate because (1 it is highly immunogenic during natural RhCMV infection, and (2 neutralizing antibodies to

  20. Bacteria modulate the degree of amphimix of their symbiotic entomopathogenic nematodes (Heterohabditis spp) in response to nutritional stress

    Science.gov (United States)

    Rincones, Johana; Mauléon, Hervé; Jaffe, Klaus

    2001-06-01

    Facultatively sexual entomopathogenic nematodes are a promising model for the experimental study of the adaptive values of sex. Our experiments in the laboratory showed that entomopathogenic nematodes display at least two different strategies in regulating the degree of amphimix as a response to nutritional stress. One strategy promotes the production of males, amphimix and the genetic variability of the offspring, improving the chances for a successful new adaptation. Another strategy increases the production of hermaphrodites at the expense of males, increasing the total number of reproductive individuals and thus the total number of offspring produced. Surprisingly, the strategy used depends upon the strain of symbiotic bacteria the nematodes are growing. The relevance of the results, in helping to discriminate between rival theories for the evolutionary maintenance of sex, is discussed.

  1. Identification of bacteria on the surface of clinically infected and non-infected prosthetic hip joints removed during revision arthroplasties by 16S rRNA gene sequencing and by microbiological culture

    Science.gov (United States)

    Dempsey, Kate E; Riggio, Marcello P; Lennon, Alan; Hannah, Victoria E; Ramage, Gordon; Allan, David; Bagg, Jeremy

    2007-01-01

    It has been postulated that bacteria attached to the surface of prosthetic hip joints can cause localised inflammation, resulting in failure of the replacement joint. However, diagnosis of infection is difficult with traditional microbiological culture methods, and evidence exists that highly fastidious or non-cultivable organisms have a role in implant infections. The purpose of this study was to use culture and culture-independent methods to detect the bacteria present on the surface of prosthetic hip joints removed during revision arthroplasties. Ten consecutive revisions were performed by two surgeons, which were all clinically and radiologically loose. Five of the hip replacement revision surgeries were performed because of clinical infections and five because of aseptic loosening. Preoperative and perioperative specimens were obtained from each patient and subjected to routine microbiological culture. The prostheses removed from each patient were subjected to mild ultrasonication to dislodge adherent bacteria, followed by aerobic and anaerobic microbiological culture. Bacterial DNA was extracted from each sonicate and the 16S rRNA gene was amplified with the universal primer pair 27f/1387r. All 10 specimens were positive for the presence of bacteria by both culture and PCR. PCR products were then cloned, organised into groups by RFLP analysis and one clone from each group was sequenced. Bacteria were identified by comparison of the 16S rRNA gene sequences obtained with those deposited in public access sequence databases. A total of 512 clones were analysed by RFLP analysis, of which 118 were sequenced. Culture methods identified species from the genera Leifsonia (54.3%), Staphylococcus (21.7%), Proteus (8.7%), Brevundimonas (6.5%), Salibacillus (4.3%), Methylobacterium (2.2%) and Zimmermannella (2.2%). Molecular detection methods identified a more diverse microflora. The predominant genus detected was Lysobacter, representing 312 (60.9%) of 512 clones

  2. Btp Proteins from Brucella abortus Modulate the Lung Innate Immune Response to Infection by the Respiratory Route.

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    Hielpos, Maria Soledad; Ferrero, Mariana C; Fernández, Andrea G; Falivene, Juliana; Vanzulli, Silvia; Comerci, Diego J; Baldi, Pablo C

    2017-01-01

    Although inhalation of infected aerosols is a frequent route for Brucella infection in humans, it rarely causes pulmonary clinical manifestations, suggesting a mild or nearly absent local inflammatory response. The goal of this study was to characterize the early innate immune response to intratracheal infection with Brucella abortus in mice and to evaluate whether it is modulated by this pathogen. After infection with 10 6  CFU of B. abortus , the pulmonary bacterial burden at 7 days post-infection (p.i.) was comparable to the initial inoculum, despite an initial transient decline. Brucella was detected in spleen and liver as early as 1 day p.i. IL-1β and MCP-1 increased at 3 days p.i., whereas IL-12, KC, TNF-α, and IFN-γ only increased at 7 days p.i. Histological examination did not reveal peribronchial or perivascular infiltrates in infected mice. Experiments were conducted to evaluate if the limited inflammatory lung response to B. abortus is caused by a bacterial mechanism of TLR signaling inhibition. Whereas inoculation of E. coli LPS to control mice [phosphate-buffered saline (PBS)/LPS] caused lung inflammation, almost no histological changes were observed in mice preinfected intratracheally with B. abortus (WT/LPS). We speculated that the Brucella TIR-containing proteins (Btps) A and B, which impair TLR signaling in vitro , may be involved in this modulation. After LPS challenge, mice preinfected with the B. abortus btpAbtpB double mutant exhibited a stronger pulmonary polymorphonuclear infiltrate than WT/LPS mice, although milder than that of the PBS/LPS group. In addition, lungs from B. abortus btpAbtpB -infected mice presented a stronger inflammatory infiltrate than those infected with the WT strain, and at day 7 p.i., the pulmonary levels of KC, MCP-1, and IL-12 were higher in mice infected with the mutant. This study shows that B. abortus infection produces a mild proinflammatory response in murine lungs, partially due to immune modulation

  3. Btp Proteins from Brucella abortus Modulate the Lung Innate Immune Response to Infection by the Respiratory Route

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    Maria Soledad Hielpos

    2017-08-01

    Full Text Available Although inhalation of infected aerosols is a frequent route for Brucella infection in humans, it rarely causes pulmonary clinical manifestations, suggesting a mild or nearly absent local inflammatory response. The goal of this study was to characterize the early innate immune response to intratracheal infection with Brucella abortus in mice and to evaluate whether it is modulated by this pathogen. After infection with 106 CFU of B. abortus, the pulmonary bacterial burden at 7 days post-infection (p.i. was comparable to the initial inoculum, despite an initial transient decline. Brucella was detected in spleen and liver as early as 1 day p.i. IL-1β and MCP-1 increased at 3 days p.i., whereas IL-12, KC, TNF-α, and IFN-γ only increased at 7 days p.i. Histological examination did not reveal peribronchial or perivascular infiltrates in infected mice. Experiments were conducted to evaluate if the limited inflammatory lung response to B. abortusis caused by a bacterial mechanism of TLR signaling inhibition. Whereas inoculation of E. coli LPS to control mice [phosphate-buffered saline (PBS/LPS] caused lung inflammation, almost no histological changes were observed in mice preinfected intratracheally with B. abortus (WT/LPS. We speculated that the Brucella TIR-containing proteins (Btps A and B, which impair TLR signaling in vitro, may be involved in this modulation. After LPS challenge, mice preinfected with the B. abortus btpAbtpB double mutant exhibited a stronger pulmonary polymorphonuclear infiltrate than WT/LPS mice, although milder than that of the PBS/LPS group. In addition, lungs from B. abortus btpAbtpB-infected mice presented a stronger inflammatory infiltrate than those infected with the WT strain, and at day 7 p.i., the pulmonary levels of KC, MCP-1, and IL-12 were higher in mice infected with the mutant. This study shows that B. abortus infection produces a mild proinflammatory response in murine lungs, partially due to immune

  4. Nasally administered Lactobacillus rhamnosus strains differentially modulate respiratory antiviral immune responses and induce protection against respiratory syncytial virus infection.

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    Tomosada, Yohsuke; Chiba, Eriko; Zelaya, Hortensia; Takahashi, Takuya; Tsukida, Kohichiro; Kitazawa, Haruki; Alvarez, Susana; Villena, Julio

    2013-08-15

    Some studies have shown that nasally administered immunobiotics had the potential to improve the outcome of influenza virus infection. However, the capacity of immunobiotics to improve protection against respiratory syncytial virus (RSV) infection was not investigated before. The aims of this study were: a) to evaluate whether the nasal administration of Lactobacillus rhamnosus CRL1505 (Lr05) and L. rhamnosus CRL1506 (Lr06) are able to improve respiratory antiviral defenses and beneficially modulate the immune response triggered by TLR3/RIG-I activation; b) to investigate whether viability of Lr05 or Lr06 is indispensable to modulate respiratory immunity and; c) to evaluate the capacity of Lr05 and Lr06 to improve the resistance of infant mice against RSV infection. Nasally administered Lr05 and Lr06 differentially modulated the TLR3/RIG-I-triggered antiviral respiratory immune response. Lr06 administration significantly modulated the production of IFN-α, IFN-β and IL-6 in the response to poly(I:C) challenge, while nasal priming with Lr05 was more effective to improve levels of IFN-γ and IL-10. Both viable Lr05 and Lr06 strains increased the resistance of infant mice to RSV infection while only heat-killed Lr05 showed a protective effect similar to those observed with viable strains. The present work demonstrated that nasal administration of immunobiotics is able to beneficially modulate the immune response triggered by TLR3/RIG-I activation in the respiratory tract and to increase the resistance of mice to the challenge with RSV. Comparative studies using two Lactobacillus rhamnosus strains of the same origin and with similar technological properties showed that each strain has an specific immunoregulatory effect in the respiratory tract and that they differentially modulate the immune response after poly(I:C) or RSV challenges, conferring different degree of protection and using distinct immune mechanisms. We also demonstrated in this work that it is possible

  5. Anaerobic bacteria

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    Anaerobic bacteria are bacteria that do not live or grow when oxygen is present. In humans, these bacteria ... Brook I. Diseases caused by non-spore-forming anaerobic bacteria. In: Goldman L, Schafer AI, eds. Goldman-Cecil ...

  6. A polyphenol-enriched diet and Ascaris suum infection modulate mucosal immune responses and gut microbiota composition in pigs.

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    Andrew R Williams

    Full Text Available Polyphenols are a class of bioactive plant secondary metabolites that are thought to have beneficial effects on gut health, such as modulation of mucosal immune and inflammatory responses and regulation of parasite burdens. Here, we examined the interactions between a polyphenol-rich diet supplement and infection with the enteric nematode Ascaris suum in pigs. Pigs were fed either a basal diet or the same diet supplemented with grape pomace (GP, an industrial by-product rich in polyphenols such as oligomeric proanthocyanidins. Half of the animals in each group were then inoculated with A. suum for 14 days to assess parasite establishment, acquisition of local and systemic immune responses and effects on the gut microbiome. Despite in vitro anthelmintic activity of GP-extracts, numbers of parasite larvae in the intestine were not altered by GP-supplementation. However, the bioactive diet significantly increased numbers of eosinophils induced by A. suum infection in the duodenum, jejunum and ileum, and modulated gene expression in the jejunal mucosa of infected pigs. Both GP-supplementation and A. suum infection induced significant and apparently similar changes in the composition of the prokaryotic gut microbiota, and both also decreased concentrations of isobutyric and isovaleric acid (branched-chain short chain fatty acids in the colon. Our results demonstrate that while a polyphenol-enriched diet in pigs may not directly influence A. suum establishment, it significantly modulates the subsequent host response to helminth infection. Our results suggest an influence of diet on immune function which may potentially be exploited to enhance immunity to helminths.

  7. Interactions between bacteria and the intestinal mucosa: Do enteric neurotransmitters acting on epithelium cells influence mucosal colonization or infection?

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    The mechanisms governing the ability of bacteria to adhere to and colonize human and animal hosts in health and disease are still incompletely understood. Throughout the extensive mucosal surfaces of the body that are in contact with the external environment, epithelial cells represent the first po...

  8. Influence of environmental factors on phage-bacteria interaction and on the efficacy and infectivity of phage P100

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    Susanne Fister

    2016-07-01

    Full Text Available When using bacteriophages to control food-borne bacteria in food production plants and processed food, it is crucial to consider that environmental conditions influence their stability. These conditions can also affect the physiological state of bacteria and consequently host-virus interaction and the effectiveness of the phage ability to reduce bacteria numbers. In this study we investigated the stability, binding and replication capability of phage P100 and its efficacy to control L. monocytogenes under conditions typically encountered in dairy plants. The influences of SDS, Lutensol AO 7, salt, smear water and different temperatures were investigated. Results indicate that phage P100 is stable and able to bind to the host under most conditions tested. Replication was dependent upon the growth of L. monocytogenes and efficacy was higher when bacterial growth was reduced by certain environmental conditions. In long-term experiments at different temperatures phages were initially able to reduce bacteria up to seven log10 units after two weeks at 4 °C. However, thereafter re-growth and development of phage-resistant L. monocytogenes isolates were encountered.

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

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    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

  10. Study the effect of stable magnetic field on the inhibition activity of Saccharomyces boulardii against pathogenic bacteria isolated from urinary tract infection

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    Nada Sabah Razouqi

    2017-09-01

    Full Text Available An increasing trend to use probiotic and study their effects on the pathogens has been conductor where they are defined as live micro-organisms that give a health benefit to the host when ingested in sufficient quantities, including the yeast Saccharomyces boulardii In addition research show that a magnetic field (MF has a biological effect. This study aims to investigate the effects of magnetic field on the inhibitory action of Saccharomyces boulardii against bacteria isolated from urinary tract infection, Study the sensitivity of bacterial isolates to antibiotics after diagnosis by microscopic, Cultural and biochemical examinations as well as Api20 E examinations were used gram negative bacteria , Most isolates were resistant to antibiotics elected, using Well diffusion method to investigate the inhibitory action of suspension and supernatant of the yeast with and without magnetic field in four different intensities (200-300-400-500 milli Tesla. The results show that inhibitory efficacy of each was higher wish increasing the magnetic field strength and differed in their impact depending on the type of bacteria and the isolate of K.pneumoniea was the most sensitive in all experiments, and suspension was more effective

  11. Application of Chemical Genomics to Plant-Bacteria Communication: A High-Throughput System to Identify Novel Molecules Modulating the Induction of Bacterial Virulence Genes by Plant Signals.

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    Vandelle, Elodie; Puttilli, Maria Rita; Chini, Andrea; Devescovi, Giulia; Venturi, Vittorio; Polverari, Annalisa

    2017-01-01

    The life cycle of bacterial phytopathogens consists of a benign epiphytic phase, during which the bacteria grow in the soil or on the plant surface, and a virulent endophytic phase involving the penetration of host defenses and the colonization of plant tissues. Innovative strategies are urgently required to integrate copper treatments that control the epiphytic phase with complementary tools that control the virulent endophytic phase, thus reducing the quantity of chemicals applied to economically and ecologically acceptable levels. Such strategies include targeted treatments that weaken bacterial pathogens, particularly those inhibiting early infection steps rather than tackling established infections. This chapter describes a reporter gene-based chemical genomic high-throughput screen for the induction of bacterial virulence by plant molecules. Specifically, we describe a chemical genomic screening method to identify agonist and antagonist molecules for the induction of targeted bacterial virulence genes by plant extracts, focusing on the experimental controls required to avoid false positives and thus ensuring the results are reliable and reproducible.

  12. Infection with multidrug-resistant gram-negative bacteria in a pediatric oncology intensive care unit: risk factors and outcomes.

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    Costa, Patrícia de Oliveira; Atta, Elias Hallack; Silva, André Ricardo Araújo da

    2015-01-01

    This study aimed at evaluating the predictors and outcomes associated with multidrug-resistant gram-negative bacterial (MDR-GNB) infections in an oncology pediatric intensive care unit (PICU). Data were collected relating to all episodes of GNB infection that occurred in a PICU between January of 2009 and December of 2012. GNB infections were divided into two groups for comparison: (1) infections attributed to MDR-GNB and (2) infections attributed to non-MDR-GNB. Variables of interest included age, gender, presence of solid tumor or hematologic disease, cancer status, central venous catheter use, previous Pseudomonas aeruginosa infection, healthcare-associated infection, neutropenia in the preceding 7 days, duration of neutropenia, length of hospital stay before ICU admission, length of ICU stay, and the use of any of the following in the previous 30 days: antimicrobial agents, corticosteroids, chemotherapy, or radiation therapy. Other variables included initial appropriate antimicrobial treatment, definitive inadequate antimicrobial treatment, duration of appropriate antibiotic use, time to initiate adequate antibiotic therapy, and the 7- and 30-day mortality. Multivariate logistic regression analyses showed significant relationships between MDR-GNB and hematologic diseases (odds ratio [OR] 5.262; 95% confidence interval [95% CI] 1.282-21.594; p=0.021) and healthcare-associated infection (OR 18.360; 95% CI 1.778-189.560; p=0.015). There were significant differences between MDR-GNB and non-MDR-GNB patients for the following variables: inadequate initial empirical antibiotic therapy, time to initiate adequate antibiotic treatment, and inappropriate antibiotic therapy. Hematologic malignancy and healthcare-associated infection were significantly associated with MDR-GNB infection in this sample of pediatric oncology patients. Copyright © 2015 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  13. Defense systems in developing Artemia franciscana nauplii and their modulation by probiotic bacteria offer protection against a Vibrio anguillarum challenge.

    Science.gov (United States)

    Giarma, Eleni; Amanetidou, Eleni; Toufexi, Alexia; Touraki, Maria

    2017-07-01

    The alterations of immune responses of Artemia franciscana nauplii as a function of culture time and after a challenge with the pathogen Vibrio anguillarum were studied. The effect of the administration of the probiotic bacteria Bacillus subtilis, Lactobacillus plantarum and Lactococcus lactis either alone or in combination with the pathogen was evaluated. The activity of the antioxidant enzymes superoxide dismutase (SOD), Glutathione reductase (GRed), Glutathione transferase (GST) and Phenoloxidase (PO) presented a significant increase as a function of culture time, appeared elevated following probiotic administration and were depleted 48 h following the experimental challenge. Lipid peroxidation reached peak levels at 48 h of culture, when nauplii start feeding and returned to lower values at 144 h, remaining however significantly higher than control (P probiotics significantly reduced lipid peroxidation in comparison with the corresponding control, while challenge with the pathogen resulted in its threefold increase. Survival of nauplii remained high throughout culture and was either increased or remained at control levels following the administration of the probiotics. The challenge with the pathogen resulted in a significantly decreased survival of 15.3% for the positive control, while in the probiotic treated series survival values were not significantly different from the negative control (P > 0.05). Following a combined administration of each probiotic and the pathogen the activities of all enzymes tested were significantly lower (P probiotic). Lipid peroxidation was significantly lower in the probiotic treated series in comparison to the positive control (P probiotics B. subtilis, L. plantarum and L. lactis protect Artemia against a V. anguillarum challenge by enhancing its immune responses thus contributing to reduced oxidative damage and increased survival. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Microbiological analysis of infected root canals from symptomatic and asymptomatic teeth with periapical periodontitis and the antimicrobial susceptibility of some isolated anaerobic bacteria.

    Science.gov (United States)

    Jacinto, R C; Gomes, B P F A; Ferraz, C C R; Zaia, A A; Filho, F J Souza

    2003-10-01

    The purpose of the present study was to investigate the correlation between the composition of the bacterial flora isolated from infected root canals of teeth with apical periodontitis with the presence of clinical signs and symptoms, and to test the antibiotic susceptibility of five anaerobic bacteria mostly commonly found in the root canals of symptomatic teeth against various substances using the E-test. Microbial samples were taken from 48 root canals, 29 symptomatic and 19 asymptomatic, using adequate techniques. A total of 218 cultivable isolates were recovered from 48 different microbial species and 19 different genera. Root canals from symptomatic teeth harbored more obligate anaerobes and a bigger number of bacterial species than the asymptomatic teeth. More than 70% of the bacterial isolates were strict anaerobes. Statistical analysis used a Pearson Chi-squared test or a one-sided Fisher's Exact test as appropriate. Suggested relationships were found between specific microorganisms, especially gram-negative anaerobes, and the presence of spontaneous or previous pain, tenderness to percussion, pain on palpation and swelling amoxicillin, amoxicillin + clavulanate and cephaclor were effective against all the strains tested. The lowest susceptibility rate was presented by Prevotella intermedia/nigrescens against Penicillin G. Our results suggested that specific bacteria are associated with endodontic symptoms of infected teeth with periapical periodontitis and the majority of the anaerobic bacterial species tested were susceptible to all antibiotics studied.

  15. Restoring Cystic Fibrosis Transmembrane Conductance Regulator Function Reduces Airway Bacteria and Inflammation in People with Cystic Fibrosis and Chronic Lung Infections.

    Science.gov (United States)

    Hisert, Katherine B; Heltshe, Sonya L; Pope, Christopher; Jorth, Peter; Wu, Xia; Edwards, Rachael M; Radey, Matthew; Accurso, Frank J; Wolter, Daniel J; Cooke, Gordon; Adam, Ryan J; Carter, Suzanne; Grogan, Brenda; Launspach, Janice L; Donnelly, Seamas C; Gallagher, Charles G; Bruce, James E; Stoltz, David A; Welsh, Michael J; Hoffman, Lucas R; McKone, Edward F; Singh, Pradeep K

    2017-06-15

    Previous work indicates that ivacaftor improves cystic fibrosis transmembrane conductance regulator (CFTR) activity and lung function in people with cystic fibrosis and G551D-CFTR mutations but does not reduce density of bacteria or markers of inflammation in the airway. These findings raise the possibility that infection and inflammation may progress independently of CFTR activity once cystic fibrosis lung disease is established. To better understand the relationship between CFTR activity, airway microbiology and inflammation, and lung function in subjects with cystic fibrosis and chronic airway infections. We studied 12 subjects with G551D-CFTR mutations and chronic airway infections before and after ivacaftor. We measured lung function, sputum bacterial content, and inflammation, and obtained chest computed tomography scans. Ivacaftor produced rapid decreases in sputum Pseudomonas aeruginosa density that began within 48 hours and continued in the first year of treatment. However, no subject eradicated their infecting P. aeruginosa strain, and after the first year P. aeruginosa densities rebounded. Sputum total bacterial concentrations also decreased, but less than P. aeruginosa. Sputum inflammatory measures decreased significantly in the first week of treatment and continued to decline over 2 years. Computed tomography scans obtained before and 1 year after ivacaftor treatment revealed that ivacaftor decreased airway mucous plugging. Ivacaftor caused marked reductions in sputum P. aeruginosa density and airway inflammation and produced modest improvements in radiographic lung disease in subjects with G551D-CFTR mutations. However, P. aeruginosa airway infection persisted. Thus, measures that control infection may be required to realize the full benefits of CFTR-targeting treatments.

  16. Antimicrobial Activity of Ephedra pachyclada Methanol Extract on Some Enteric Gram Negative Bacteria Which Causes Nosocomial Infections by Agar Dilution Method

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    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.

  17. Genomes of the most dangerous epidemic bacteria have a virulence repertoire characterized by fewer genes but more toxin-antitoxin modules.

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    Kalliopi Georgiades

    2011-03-01

    Full Text Available We conducted a comparative genomic study based on a neutral approach to identify genome specificities associated with the virulence capacity of pathogenic bacteria. We also determined whether virulence is dictated by rules, or if it is the result of individual evolutionary histories. We systematically compared the genomes of the 12 most dangerous pandemic bacteria for humans ("bad bugs" to their closest non-epidemic related species ("controls".We found several significantly different features in the "bad bugs", one of which was a smaller genome that likely resulted from a degraded recombination and repair system. The 10 Cluster of Orthologous Group (COG functional categories revealed a significantly smaller number of genes in the "bad bugs", which lacked mostly transcription, signal transduction mechanisms, cell motility, energy production and conversion, and metabolic and regulatory functions. A few genes were identified as virulence factors, including secretion system proteins. Five "bad bugs" showed a greater number of poly (A tails compared to the controls, whereas an elevated number of poly (A tails was found to be strongly correlated to a low GC% content. The "bad bugs" had fewer tandem repeat sequences compared to controls. Moreover, the results obtained from a principal component analysis (PCA showed that the "bad bugs" had surprisingly more toxin-antitoxin modules than did the controls.We conclude that pathogenic capacity is not the result of "virulence factors" but is the outcome of a virulent gene repertoire resulting from reduced genome repertoires. Toxin-antitoxin systems could participate in the virulence repertoire, but they may have developed independently of selfish evolution.

  18. Infection of C57BL/6 mice by Trypanosoma musculi modulates host immune responses during Brucella abortus cocolonization.

    Science.gov (United States)

    Lowry, Jake E; Leonhardt, Jack A; Yao, Chaoqun; Belden, E Lee; Andrews, Gerard P

    2014-01-01

    Brucellosis, which results in fetal abortions in domestic and wildlife animal populations, is of major concern in the US and throughout much of the world. The disease, caused by Brucella abortus, poses an economic threat to agriculture-based communities. A moderately efficacious live attenuated vaccine (B. abortus strain RB51) exists. However, even with vaccine use, outbreaks occur. Evidence suggests that elk (Cervus canadensis), a wild host reservoir, are the source of recent outbreaks in domestic cattle herds in Wyoming, USA. Brucella abortus establishes a chronic, persistent infection in elk. The molecular mechanisms allowing the establishment of this persistent infective state are currently unknown. A potential mechanism could be that concurrent pathogen burdens contribute to persistence. In Wyoming, elk are chronically infected with Trypanosoma cervi, which may modulate host responses in a similar manner to that documented for other trypanosomes. To identify any synergistic relationship between the two pathogens, we simulated coinfection in the well-established murine brucellosis model using Trypanosoma musculi and B. abortus S19. Groups of C57BL/6 mice (Mus musculus) were infected with either B. abortus strain 19 (S19) or T. musculi or both. Sera were collected weekly; spleens from euthanized mice were tested to determine bacterial load near the end of normal brucellosis infection. Although changes in bacterial load were observed during the later stages of brucellosis in those mice coinfected with T. musculi, the most significant finding was the suppression of gamma interferon early during the infection along with an increase in interleukin-10 secretion compared with mice infected with either pathogen alone. These results suggest that immune modulatory events occur in the mouse during coinfection and that further experiments are warranted to determine if T. cervi impacts Brucella infection in elk.

  19. Susceptibility to rifaximin and other antimicrobials of bacteria isolated in patients with acute gastrointestinal infections in Southeast Mexico.

    Science.gov (United States)

    Novoa-Farias, O; Frati-Munari, A C; Peredo, M A; Flores-Juárez, S; Novoa-García, O; Galicia-Tapia, J; Romero-Carpio, C E

    Enteropathogenic bacteria isolated in Mexico City have shown a high rate of resistance to different antibiotics, with the exception of rifaximin (RIF). RIF is a nonabsorbable antibiotic that reaches high fecal concentrations (≈ 8,000μg/g). Susceptibility to antimicrobials can vary in different geographic regions. To study the susceptibility to rifaximin and other antimicrobials of enteropathogenic bacteria isolated in patients with acute diarrhea in the southeastern region of Mexico. A total of 614 strains of bacteria isolated from patients with acute diarrhea from 4 cities in Southeast Mexico were analyzed. An antibiogram with the following antibiotics was created: ampicillin (AMP), trimethoprim/sulfamethoxazole (T-S), neomycin (NEO), furazolidone (FUR), ciprofloxacin (CIP), chloramphenicol (CHL), and fosfomycin (FOS), assessed through the agar diffusion method at the standard concentrations recommended by the Clinical and Laboratory Standards Institute (CLSI) and the American Society for Microbiology (ASM), and RIF, assessed through microdilution at 4 concentrations. The bacteria were Escherichia coli (55%), as the majority, in all its pathogenic variants, Shigella (16.8%), Salmonella (15.3%), Aeromonas (7.8%), and less than 5% Campylobacter, Yersinia, Vibrio, and Plesiomonas. The accumulated overall susceptibility to RIF was 69.1, 90.8, 98.9, and 100% at concentrations of 100, 200, 400, and 800μg/ml, respectively. Overall susceptibility to other antibiotics was FOS 82.8%, CHL 76.8%, CIP 73.9%, FUR 64%, T-S 58.7%, NEO 55.8%, and AMP 23.8%. Susceptibility to RIF at 400 and 800μg was significantly greater than with the other antimicrobials (P 98% of the bacterial strains and a high frequency of resistance to several common antimicrobials. Copyright © 2017 Asociación Mexicana de Gastroenterología. Publicado por Masson Doyma México S.A. All rights reserved.

  20. HBV core protein allosteric modulators differentially alter cccDNA biosynthesis from de novo infection and intracellular amplification pathways

    Science.gov (United States)

    Guo, Fang; Zhao, Qiong; Cheng, Junjun; Qi, Yonghe; Su, Qing; Wei, Lai; Li, Wenhui; Chang, Jinhong

    2017-01-01

    Hepatitis B virus (HBV) core protein assembles viral pre-genomic (pg) RNA and DNA polymerase into nucleocapsids for reverse transcriptional DNA replication to take place. Several chemotypes of small molecules, including heteroaryldihydropyrimidines (HAPs) and sulfamoylbenzamides (SBAs), have been discovered to allosterically modulate core protein structure and consequentially alter the kinetics and pathway of core protein assembly, resulting in formation of irregularly-shaped core protein aggregates or “empty” capsids devoid of pre-genomic RNA and viral DNA polymerase. Interestingly, in addition to inhibiting nucleocapsid assembly and subsequent viral genome replication, we have now demonstrated that HAPs and SBAs differentially modulate the biosynthesis of covalently closed circular (ccc) DNA from de novo infection and intracellular amplification pathways by inducing disassembly of nucleocapsids derived from virions as well as double-stranded DNA-containing progeny nucleocapsids in the cytoplasm. Specifically, the mistimed cuing of nucleocapsid uncoating prevents cccDNA formation during de novo infection of hepatocytes, while transiently accelerating cccDNA synthesis from cytoplasmic progeny nucleocapsids. Our studies indicate that elongation of positive-stranded DNA induces structural changes of nucleocapsids, which confers ability of mature nucleocapsids to bind CpAMs and triggers its disassembly. Understanding the molecular mechanism underlying the dual effects of the core protein allosteric modulators on nucleocapsid assembly and disassembly will facilitate the discovery of novel core protein-targeting antiviral agents that can more efficiently suppress cccDNA synthesis and cure chronic hepatitis B. PMID:28945802

  1. HBV core protein allosteric modulators differentially alter cccDNA biosynthesis from de novo infection and intracellular amplification pathways.

    Science.gov (United States)

    Guo, Fang; Zhao, Qiong; Sheraz, Muhammad; Cheng, Junjun; Qi, Yonghe; Su, Qing; Cuconati, Andrea; Wei, Lai; Du, Yanming; Li, Wenhui; Chang, Jinhong; Guo, Ju-Tao

    2017-09-01

    Hepatitis B virus (HBV) core protein assembles viral pre-genomic (pg) RNA and DNA polymerase into nucleocapsids for reverse transcriptional DNA replication to take place. Several chemotypes of small molecules, including heteroaryldihydropyrimidines (HAPs) and sulfamoylbenzamides (SBAs), have been discovered to allosterically modulate core protein structure and consequentially alter the kinetics and pathway of core protein assembly, resulting in formation of irregularly-shaped core protein aggregates or "empty" capsids devoid of pre-genomic RNA and viral DNA polymerase. Interestingly, in addition to inhibiting nucleocapsid assembly and subsequent viral genome replication, we have now demonstrated that HAPs and SBAs differentially modulate the biosynthesis of covalently closed circular (ccc) DNA from de novo infection and intracellular amplification pathways by inducing disassembly of nucleocapsids derived from virions as well as double-stranded DNA-containing progeny nucleocapsids in the cytoplasm. Specifically, the mistimed cuing of nucleocapsid uncoating prevents cccDNA formation during de novo infection of hepatocytes, while transiently accelerating cccDNA synthesis from cytoplasmic progeny nucleocapsids. Our studies indicate that elongation of positive-stranded DNA induces structural changes of nucleocapsids, which confers ability of mature nucleocapsids to bind CpAMs and triggers its disassembly. Understanding the molecular mechanism underlying the dual effects of the core protein allosteric modulators on nucleocapsid assembly and disassembly will facilitate the discovery of novel core protein-targeting antiviral agents that can more efficiently suppress cccDNA synthesis and cure chronic hepatitis B.

  2. HBV core protein allosteric modulators differentially alter cccDNA biosynthesis from de novo infection and intracellular amplification pathways.

    Directory of Open Access Journals (Sweden)

    Fang Guo

    2017-09-01

    Full Text Available Hepatitis B virus (HBV core protein assembles viral pre-genomic (pg RNA and DNA polymerase into nucleocapsids for reverse transcriptional DNA replication to take place. Several chemotypes of small molecules, including heteroaryldihydropyrimidines (HAPs and sulfamoylbenzamides (SBAs, have been discovered to allosterically modulate core protein structure and consequentially alter the kinetics and pathway of core protein assembly, resulting in formation of irregularly-shaped core protein aggregates or "empty" capsids devoid of pre-genomic RNA and viral DNA polymerase. Interestingly, in addition to inhibiting nucleocapsid assembly and subsequent viral genome replication, we have now demonstrated that HAPs and SBAs differentially modulate the biosynthesis of covalently closed circular (ccc DNA from de novo infection and intracellular amplification pathways by inducing disassembly of nucleocapsids derived from virions as well as double-stranded DNA-containing progeny nucleocapsids in the cytoplasm. Specifically, the mistimed cuing of nucleocapsid uncoating prevents cccDNA formation during de novo infection of hepatocytes, while transiently accelerating cccDNA synthesis from cytoplasmic progeny nucleocapsids. Our studies indicate that elongation of positive-stranded DNA induces structural changes of nucleocapsids, which confers ability of mature nucleocapsids to bind CpAMs and triggers its disassembly. Understanding the molecular mechanism underlying the dual effects of the core protein allosteric modulators on nucleocapsid assembly and disassembly will facilitate the discovery of novel core protein-targeting antiviral agents that can more efficiently suppress cccDNA synthesis and cure chronic hepatitis B.

  3. Effects of Helicobacter pylori, geohelminth infection and selected commensal bacteria on the risk of allergic disease and sensitization in 3-year-old Ethiopian children.

    Science.gov (United States)

    Amberbir, A; Medhin, G; Erku, W; Alem, A; Simms, R; Robinson, K; Fogarty, A; Britton, J; Venn, A; Davey, G

    2011-10-01

    Epidemiological studies have suggested that gastro-intestinal infections including Helicobacter pylori, intestinal microflora (commensal bacteria) and geohelminths may influence the risk of asthma and allergy but data from early life are lacking. We aimed to determine the independent effects of these infections on allergic disease symptoms and sensitization in an Ethiopian birth cohort. In 2008/09, 878 children (87% of the 1006 original singletons in a population-based birth cohort) were followed up at age 3 and interview data obtained on allergic symptoms and potential confounders. Allergen skin tests to Dermatophagoides pteronyssinus and cockroach were performed, levels of Der p 1 and Bla g 1 in the child's bedding measured and stool samples analysed for geohelminths and, in a random subsample, enterococci, lactobacilli, bifidobacteria and H. pylori antigen. The independent effects of each exposure on wheeze, eczema, hayfever and sensitization were determined using multiple logistic regression. Children were commonly infected with H. pylori (41%; 253/616), enterococci (38.1%; 207/544), lactobacilli (31.1%; 169/544) and bifidobacteria (18.9%; 103/544) whereas geohelminths were only found in 8.5% (75/866). H. pylori infection was associated with a borderline significant reduced risk of eczema (adjusted OR 0.49, 95% CI 0.24-1.01, P=0.05) and D. pteronyssinus sensitization (adjusted OR 0.42, 95% CI 0.17-1.08, P=0.07). Geohelminths and intestinal microflora were not significantly associated with any of the outcomes measured. Among young children in a developing country, we found evidence to support the hypothesis of a protective effect of H. pylori infection on the risk of allergic disease. Further investigation of the mechanism of this effect is therefore of potential therapeutic and preventive value. © 2011 Blackwell Publishing Ltd.

  4. Innate invariant NKT cells recognize Mycobacterium tuberculosis-infected macrophages, produce interferon-gamma, and kill intracellular bacteria.

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    Isabel Sada-Ovalle

    2008-12-01

    Full Text Available Cellular immunity to Mycobacterium tuberculosis (Mtb requires a coordinated response between the innate and adaptive arms of the immune system, resulting in a type 1 cytokine response, which is associated with control of infection. The contribution of innate lymphocytes to immunity against Mtb remains controversial. We established an in vitro system to study this question. Interferon-gamma is produced when splenocytes from uninfected mice are cultured with Mtb-infected macrophages, and, under these conditions, bacterial replication is suppressed. This innate control of bacterial replication is dependent on CD1d-restricted invariant NKT (iNKT cells, and their activation requires CD1d expression by infected macrophages as well as IL-12 and IL-18. We show that iNKT cells, even in limiting quantities, are sufficient to restrict Mtb replication. To determine whether iNKT cells contribute to host defense against tuberculosis in vivo, we adoptively transferred iNKT cells into mice. Primary splenic iNKT cells obtained from uninfected mice significantly reduce the bacterial burden in the lungs of mice infected with virulent Mtb by the aerosol route. Thus, iNKT cells have a direct bactericidal effect, even in the absence of synthetic ligands such as alpha-galactosylceramide. Our finding that iNKT cells protect mice against aerosol Mtb infection is the first evidence that CD1d-restricted NKT cells mediate protection against Mtb in vivo.

  5. Port d’Entrée for Respiratory Infections – Does the Influenza A Virus Pave the Way for Bacteria?

    Directory of Open Access Journals (Sweden)

    Nikolai Siemens

    2017-12-01

    Full Text Available Bacterial and viral co-infections of the respiratory tract are life-threatening and present a global burden to the global community. Staphylococcus aureus, Streptococcus pneumoniae, and Streptococcus pyogenes are frequent colonizers of the upper respiratory tract. Imbalances through acquisition of seasonal viruses, e.g., Influenza A virus, can lead to bacterial dissemination to the lower respiratory tract, which in turn can result in severe pneumonia. In this review, we summarize the current knowledge about bacterial and viral co-infections of the respiratory tract and focus on potential experimental models suitable for mimicking this disease. Transmission of IAV and pneumonia is mainly modeled by mouse infection. Few studies utilizing ferrets, rats, guinea pigs, rabbits, and non-human primates are also available. The knowledge gained from these studies led to important discoveries and advances in understanding these infectious diseases. Nevertheless, mouse and other infection models have limitations, especially in translation of the discoveries to humans. Here, we suggest the use of human engineered lung tissue, human ex vivo lung tissue, and porcine models to study respiratory co-infections, which might contribute to a greater translation of the results to humans and improve both, animal and human health.

  6. The efficacy of 16S ribosomal DNA sequencing in the diagnosis of bacteria from blood, bone and synovial fluid samples of children with musculoskeletal infections.

    Science.gov (United States)

    Hashavya, S; Gross, I; Michael-Gayego, A; Simanovsky, N; Lamdan, R

    2018-04-01

    Musculoskeletal infections are among the most common bacterial infections in children leading to hospitalization, invasive procedures and prolonged antibiotic administration. Blood, synovial and sometimes tissue cultures are essential for the diagnosis and treatment of musculoskeletal infections; 16S ribosomal DNA (rDNA) sequencing is a novel diagnostic tool for the detection of bacteria.While the yield of 16S rDNA sequencing in synovial fluid was previously assessed, data regarding the efficacy of this method from blood samples or partially treated children with suspected musculoskeletal infections is lacking.In this study we assessed the yield of 16S rDNA sequencing in blood, bone and synovial samples of children with musculoskeletal infections. Blood, synovial and bone samples were collected from children with suspected musculoskeletal infections and analyzed for the presence of 16S rDNA, the results were then compared with the benchmark microbial cultures. During the study period, 41 children (18 boys and 23 girls) with suspected acute musculoskeletal infection were enrolled. A positive blood culture was found in 6/31 cases (19.4%) with methicillin-susceptible Staphylococcus aureus being the most commonly isolated bacterium. No significant 16S rDNA detection in blood samples was recorded.Synovial fluid culture was positive in 6/28 samples (21%), Kingella kingae being the most common pathogen. When using the 16S rDNA sequencing method, the rate of positive results in synovial fluid was higher with bacterial detection in 12/23 (52%) samples. The 16S rDNA sequencing method was also able to identify pathogens in samples taken from partially treated children where cultures were negative with 16S rDNA detection in 5/5 samples. Although 16S rDNA sequencing may increase the yield of bacterial detection in synovial samples of patients with musculoskeletal infections, there is no benefit from applying this method on blood samples. The 16S rDNA sequencing method may be

  7. Interactions between bacteria and the gut mucosa: Do enteric neurotransmitters acting on the mucosal epithelium influence intestinal colonization or infection?

    Science.gov (United States)

    The intestinal epithelium is a critical barrier between the internal and external milieux of the mammalian host. Epithelial interactions between these two host environments have been shown to be modulated by several different, cross-communicating cell types residing in the gut mucosa. These include ...

  8. Pathogen translocation and histopathological lesions in an experimental model of Salmonella Dublin infection in calves receiving lactic acid bacteria and lactose supplements

    Science.gov (United States)

    Zbrun, María V.; Soto, Lorena P.; Bertozzi, Ezequiel; Sequeira, Gabriel J.; Marti, Luis E.; Signorini, Marcelo L.; Armesto, Roberto Rodríguez; Rosmini, Marcelo R.

    2012-01-01

    The purpose of this study was to evaluate the capacity of a lactic acid bacteria (LAB) inoculum to protect calves with or without lactose supplements against Salmonella Dublin infection by evaluating histopathological lesions and pathogen translocation. Fifteen calves were divided into three groups [control group (C-G), a group inoculated with LAB (LAB-G), and a group inoculated with LAB and given lactose supplements (L-LAB-G)] with five, six, and four animals, respectively. The inoculum, composed of Lactobacillus (L.) casei DSPV 318T, L. salivarius DSPV 315T, and Pediococcus acidilactici DSPV 006T, was administered with milk replacer. The LAB-G and L-LAB-G received a daily dose of 109 CFU/kg body weight of each strain throughout the experiment. Lactose was provided to the L-LAB-G in doses of 100 g/day. Salmonella Dublin (2 × 1010 CFU) was orally administered to all animals on day 11 of the experiment. The microscopic lesion index values in target organs were 83%, 70%, and 64.3% (p < 0.05) for the C-G, LAB-G, and L-LAB-G, respectively. Administration of the probiotic inoculum was not fully effective against infection caused by Salmonella. Although probiotic treatment was unable to delay the arrival of pathogen to target organs, it was evident that the inoculum altered the response of animals against pathogen infection. PMID:23000583

  9. Adults hospitalised with acute respiratory illness rarely have detectable bacteria in the absence of COPD or pneumonia; viral infection predominates in a large prospective UK sample.

    Science.gov (United States)

    Clark, Tristan W; Medina, Marie-jo; Batham, Sally; Curran, Martin D; Parmar, Surendra; Nicholson, Karl G

    2014-11-01

    Many adult patients hospitalised with acute respiratory illness have viruses detected but the overall importance of viral infection compared to bacterial infection is unclear. Patients were recruited from two acute hospital sites in Leicester (UK) over 3 successive winters. Samples were taken for viral and bacterial testing. Of the 780 patients hospitalised with acute respiratory illness 345 (44%) had a respiratory virus detected. Picornaviruses were the most commonly isolated viruses (detected in 23% of all patients). Virus detection rates exceeded 50% in patients with exacerbation of asthma (58%), acute bronchitis and Influenza-like-illness (64%), and ranged from 30 to 50% in patients with an exacerbation of COPD (38%), community acquired pneumonia (36%) and congestive cardiac failure (31%). Bacterial detection was relatively frequent in patients with exacerbation of COPD and pneumonia (25% and 33% respectively) but was uncommon in all other groups. Antibiotic use was high across all clinical groups (76% overall) and only 21% of all antibiotic use occurred in patients with detectable bacteria. Respiratory viruses are the predominant detectable aetiological agents in most hospitalised adults with acute respiratory illness. Antibiotic usage in hospital remains excessive including in clinical conditions associated with low rates of bacterial detection. Efforts at reducing excess antibiotic use should focus on these groups as a priority. Registered International Standard Controlled Trial Number: 21521552. Copyright © 2014 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

  10. Anaerobic bacteria in 118 patients with deep-space head and neck infections from the University Hospital of Maxillofacial Surgery, Sofia, Bulgaria.

    Science.gov (United States)

    Boyanova, Lyudmila; Kolarov, Rossen; Gergova, Galina; Deliverska, Elitsa; Madjarov, Jivko; Marinov, Milen; Mitov, Ivan

    2006-09-01

    The aim of this study was to assess the incidence and susceptibility to antibacterial agents of anaerobic strains in 118 patients with head and neck abscesses (31) and cellulitis (87). Odontogenic infection was the most common identified source, occurring in 73 (77.7%) of 94 patients. The incidence of anaerobes in abscesses and cellulitis was 71 and 75.9%, respectively, and that in patients before (31 patients) and after (87) the start of empirical treatment was 80.6 and 72.4%, respectively. The detection rates of anaerobes in patients with odontogenic and other sources of infection were 82.2 and 71.4%, respectively. In total, 174 anaerobic strains were found. The predominant bacteria were Prevotella (49 strains), Fusobacterium species (22), Actinomyces spp. (21), anaerobic cocci (20) and Eubacterium spp. (18). Bacteroides fragilis strains were isolated from 7 (5.9%) specimens. The detection rate of Fusobacterium strains from non-treated patients (32.2%) was higher than that from treated patients (13.8%). Resistance rates to clindamycin and metronidazole of Gram-negative anaerobes were 5.4 and 2.5%, respectively, and those of Gram-positive species were 4.5 and 58.3%, respectively. One Prevotella strain was intermediately susceptible to ampicillin/sulbactam. In conclusion, the start of empirical treatment could influence the frequency or rate of isolation of Fusobacterium species. The involvement of the Bacteroides fragilis group in some head and neck infections should be considered.

  11. Modulation of inflammatory bowel disease in a mouse model following infection with Trichinella spiralis

    Science.gov (United States)

    Infection of mice with Trichinella spiralis redirects the mucosal immune system from a Th1 to a protective Th2 response with a reduction in the severity of trinitrobenzesulfonic acid-induced colonic damage. T. spiralis infection induced IL-10 production in a dose-dependent manner in oxazolone (OXZ)-...

  12. A computerized education module improves patient knowledge and attitudes about appropriate antibiotic use for acute respiratory tract infections.

    Science.gov (United States)

    Price, Erika Leemann; Mackenzie, Thomas D; Metlay, Joshua P; Camargo, Carlos A; Gonzales, Ralph

    2011-12-01

    Over-use of antibiotics for acute respiratory infections (ARIs) increases antimicrobial resistance, treatment costs, and side effects. Patient desire for antibiotics contributes to over-use. To explore whether a point-of-care interactive computerized education module increases patient knowledge and decreases desire for antibiotics. Bilingual (English/Spanish) interactive kiosks were available in 8 emergency departments as part of a multidimensional intervention to reduce antibiotic prescribing for ARIs. The symptom-tailored module included assessment of symptoms, knowledge about ARIs (3 items), and desire for antibiotics on a 10-point visual analog scale. Multivariable analysis assessed predictors of change in desire for antibiotics. Of 686 adults with ARI symptoms, 63% initially thought antibiotics might help. The proportion of patients with low (1-3 on the scale) desire for antibiotics increased from 22% pre-module to 49% post-module (pknowledge about antibiotics and ARIs. Learning correlated with changes in personal desire for antibiotics. By reducing desire for antibiotics, point-of-care interactive educational computer technology may help decrease inappropriate use for antibiotics for ARIs. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  13. Complex interactions between potentially pathogenic, opportunistic, and resident bacteria emerge during infection on a reef-building coral.

    Science.gov (United States)

    Gignoux-Wolfsohn, Sarah A; Aronson, Felicia M; Vollmer, Steven V

    2017-07-01

    Increased bacterial diversity on diseased corals can obscure disease etiology and complicate our understanding of pathogenesis. To untangle microbes that may cause white band disease signs from microbes responding to disease, we inoculated healthy Acropora cervicornis corals with an infectious dose from visibly diseased corals. We sampled these dosed corals and healthy controls over time for sequencing of the bacterial 16S region. Endozoicomonas were associated with healthy fragments from 4/10 colonies, dominating microbiomes before dosing and decreasing over time only in corals that displayed disease signs, suggesting a role in disease resistance. We grouped disease-associated bacteria by when they increased in abundance (primary vs secondary) and whether they originated in the dose (colonizers) or the previously healthy corals (responders). We found that all primary responders increased in all dosed corals regardless of final disease state and are therefore unlikely to cause disease signs. In contrast, primary colonizers in the families Pasteurellaceae and Francisellaceae increased solely in dosed corals that ultimately displayed disease signs, and may be infectious foreign bacteria involved in the development of disease signs. Moving away from a static comparison of diseased and healthy bacterial communities, we provide a framework to identify key players in other coral diseases. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. Susceptibility to rifaximin and other antimicrobials of bacteria isolated in patients with acute gastrointestinal infections in Southeast Mexico

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    O. Novoa-Farias

    2017-07-01

    Full Text Available Introduction: Enteropathogenic bacteria isolated in Mexico City have shown a high rate of resistance to different antibiotics, with the exception of rifaximin (RIF. RIF is a nonabsorbable antibiotic that reaches high fecal concentrations (≈ 8,000 μg/g. Susceptibility to antimicrobials can vary in different geographic regions. Aim: To study the susceptibility to rifaximin and other antimicrobials of enteropathogenic bacteria isolated in patients with acute diarrhea in the southeastern region of Mexico. Material and methods: A total of 614 strains of bacteria isolated from patients with acute diarrhea from 4 cities in Southeast Mexico were analyzed. An antibiogram with the following antibiotics was created: ampicillin (AMP, trimethoprim/sulfamethoxazole (T-S, neomycin (NEO, furazolidone (FUR, ciprofloxacin (CIP, chloramphenicol (CHL, and fosfomycin (FOS, assessed through the agar diffusion method at the standard concentrations recommended by the Clinical and Laboratory Standards Institute (CLSI and the American Society for Microbiology (ASM, and RIF, assessed through microdilution at 4 concentrations. Results: The bacteria were Escherichia coli (55%, as the majority, in all its pathogenic variants, Shigella (16.8%, Salmonella (15.3%, Aeromonas (7.8%, and less than 5% Campylobacter, Yersinia, Vibrio, and Plesiomonas. The accumulated overall susceptibility to RIF was 69.1, 90.8, 98.9, and 100% at concentrations of 100, 200, 400, and 800 μg/ml, respectively. Overall susceptibility to other antibiotics was FOS 82.8%, CHL 76.8%, CIP 73.9%, FUR 64%, T-S 58.7%, NEO 55.8%, and AMP 23.8%. Susceptibility to RIF at 400 and 800 μg was significantly greater than with the other antimicrobials (P 98% of the bacterial strains and a high frequency of resistance to several common antimicrobials. Resumen: Antecedentes: Bacterias enteropatógenas aisladas en la Ciudad de México han mostrado una alta tasa de resistencia a diversos antibi

  15. Toxoplasma gondii infection reduces predator aversion in rats through epigenetic modulation in the host medial amygdala.

    Science.gov (United States)

    Hari Dass, Shantala Arundhati; Vyas, Ajai

    2014-12-01

    Male rats (Rattus novergicus) infected with protozoan Toxoplasma gondii relinquish their innate aversion to the cat odours. This behavioural change is postulated to increase transmission of the parasite to its definitive felid hosts. Here, we show that the Toxoplasma gondii infection institutes an epigenetic change in the DNA methylation of the arginine vasopressin promoter in the medial amygdala of male rats. Infected animals exhibit hypomethylation of arginine vasopressin promoter, leading to greater expression of this nonapeptide. The infection also results in the greater activation of the vasopressinergic neurons after exposure to the cat odour. Furthermore, we show that loss of fear in the infected animals can be rescued by the systemic hypermethylation and recapitulated by directed hypomethylation in the medial amygdala. These results demonstrate an epigenetic proximate mechanism underlying the extended phenotype in the Rattus novergicus-Toxoplasma gondii association. © 2014 John Wiley & Sons Ltd.

  16. Soluble granzymes are released during human endotoxemia and in patients with severe infection due to gram-negative bacteria

    NARCIS (Netherlands)

    Lauw, F. N.; Simpson, A. J.; Hack, C. E.; Prins, J. M.; Wolbink, A. M.; van Deventer, S. J.; Chaowagul, W.; White, N. J.; van der Poll, T.

    2000-01-01

    Extracellular release of granzymes is considered to reflect the involvement of cytotoxic T lymphocytes and NK cells in various disease states. To obtain insight into granzyme release during bacterial infection, granzyme levels were measured during experimental human endotoxemia and in patients with

  17. Nonstructural 3 Protein of Hepatitis C Virus Modulates the Tribbles Homolog 3/Akt Signaling Pathway for Persistent Viral Infection

    Science.gov (United States)

    Tran, Si C.; Pham, Tu M.; Nguyen, Lam N.; Park, Eun-Mee; Lim, Yun-Sook

    2016-01-01

    ABSTRACT Hepatitis C virus (HCV) infection often causes chronic hepatitis, liver cirrhosis, and ultimately hepatocellular carcinoma. However, the mechanisms underlying HCV-induced liver pathogenesis are still not fully understood. By transcriptome sequencing (RNA-Seq) analysis, we recently identified host genes that were significantly differentially expressed in cell culture-grown HCV (HCVcc)-infected cells. Of these, tribbles homolog 3 (TRIB3) was selected for further characterization. TRIB3 was initially identified as a binding partner of protein kinase B (also known as Akt). TRIB3 blocks the phosphorylation of Akt and induces apoptosis under endoplasmic reticulum (ER) stress conditions. HCV has been shown to enhance Akt phosphorylation for its own propagation. In the present study, we demonstrated that both mRNA and protein levels of TRIB3 were increased in the context of HCV replication. We further showed that promoter activity of TRIB3 was increased by HCV-induced ER stress. Silencing of TRIB3 resulted in increased RNA and protein levels of HCV, whereas overexpression of TRIB3 decreased HCV replication. By employing an HCV pseudoparticle entry assay, we further showed that TRIB3 was a negative host factor involved in HCV entry. Both in vitro binding and immunoprecipitation assays demonstrated that HCV NS3 specifically interacted with TRIB3. Consequently, the association of TRIB3 and Akt was disrupted by HCV NS3, and thus, TRIB3-Akt signaling was impaired in HCV-infected cells. Moreover, HCV modulated TRIB3 to promote extracellular signal-regulated kinase (ERK) phosphorylation, activator protein 1 (AP-1) activity, and cell migration. Collectively, these data indicate that HCV exploits the TRIB3-Akt signaling pathway to promote persistent viral infection and may contribute to HCV-mediated pathogenesis. IMPORTANCE TRIB3 is a pseudokinase protein that acts as an adaptor in signaling pathways for important cellular processes. So far, the functional involvement of

  18. Investigating the Effect of Different Treatments with Lactic Acid Bacteria on the Fate of Listeria monocytogenes and Staphylococcus aureus Infection in Galleria mellonella Larvae.

    Science.gov (United States)

    Grounta, Athena; Harizanis, Paschalis; Mylonakis, Eleftherios; Nychas, George-John E; Panagou, Efstathios Z

    2016-01-01

    The use of Galleria mellonella as a model host to elucidate microbial pathogenesis and search for novel drugs and therapies has been well appreciated over the past years. However, the effect of microorganisms with functional appeal in the specific host remains scarce. The present study investigates the effect of treatment with selected lactic acid bacteria (LAB) with probiotic potential, as potential protective agents by using live or heat-killed cells at 6 and 24 h prior to infection with Listeria monocytogenes and Staphylococcus aureus or as potential therapeutic agents by using cell-free supernatants (CFS) after infection with the same pathogens. The employed LAB strains were Lactobacillus pentosus B281 and Lactobacillus plantarum B282 (isolated from table olive fermentations) along with Lactobacillus rhamnosus GG (inhabitant of human intestinal tract). Kaplan-Meier survival curves were plotted while the pathogen's persistence in the larval hemolymph was determined by microbiological analysis. It was observed that the time (6 or 24 h) and type (live or heat-killed cells) of challenge period with LAB prior to infection greatly affected the survival of infected larvae. The highest decrease of L. monocytogenes population in the hemolymph was observed in groups challenged for 6 h with heat-killed cells by an average of 1.8 log units compared to non challenged larvae for strains B281 (p 0.0322), B282 (p 0.0325), and LGG (p 0.0356). In the case of S. aureus infection, the population of the pathogen decreased in the hemolymph by 1 log units at 8 h post infection in the groups challenged for 6 h with heat-killed cells of strains B281 (p 0.0161) and B282 (p 0.0096) and by 1.8 log units in groups challenged with heat-killed cells of LGG strain (p 0.0175). Further use of CFS of each LAB strain did not result in any significant prolonged survival but interestingly it resulted in pronounced decrease of L. monocytogenes in the hemolymph at 24 h and 48 h after infection by

  19. Investigating the Effect of Different Treatments with Lactic Acid Bacteria on the Fate of Listeria monocytogenes and Staphylococcus aureus Infection in Galleria mellonella Larvae.

    Directory of Open Access Journals (Sweden)

    Athena Grounta

    Full Text Available The use of Galleria mellonella as a model host to elucidate microbial pathogenesis and search for novel drugs and therapies has been well appreciated over the past years. However, the effect of microorganisms with functional appeal in the specific host remains scarce. The present study investigates the effect of treatment with selected lactic acid bacteria (LAB with probiotic potential, as potential protective agents by using live or heat-killed cells at 6 and 24 h prior to infection with Listeria monocytogenes and Staphylococcus aureus or as potential therapeutic agents by using cell-free supernatants (CFS after infection with the same pathogens. The employed LAB strains were Lactobacillus pentosus B281 and Lactobacillus plantarum B282 (isolated from table olive fermentations along with Lactobacillus rhamnosus GG (inhabitant of human intestinal tract. Kaplan-Meier survival curves were plotted while the pathogen's persistence in the larval hemolymph was determined by microbiological analysis. It was observed that the time (6 or 24 h and type (live or heat-killed cells of challenge period with LAB prior to infection greatly affected the survival of infected larvae. The highest decrease of L. monocytogenes population in the hemolymph was observed in groups challenged for 6 h with heat-killed cells by an average of 1.8 log units compared to non challenged larvae for strains B281 (p 0.0322, B282 (p 0.0325, and LGG (p 0.0356. In the case of S. aureus infection, the population of the pathogen decreased in the hemolymph by 1 log units at 8 h post infection in the groups challenged for 6 h with heat-killed cells of strains B281 (p 0.0161 and B282 (p 0.0096 and by 1.8 log units in groups challenged with heat-killed cells of LGG strain (p 0.0175. Further use of CFS of each LAB strain did not result in any significant prolonged survival but interestingly it resulted in pronounced decrease of L. monocytogenes in the hemolymph at 24 h and 48 h after

  20. Plants used in Guatemala for the treatment of protozoal infections. I. Screening of activity to bacteria, fungi and American trypanosomes of 13 native plants.

    Science.gov (United States)

    Cáceres, A; López, B; González, S; Berger, I; Tada, I; Maki, J

    1998-10-01

    Extracts were prepared from 13 native plants used for the treatment of protozoal infections. Activity against bacteria and fungi was demonstrated by dilution procedures; Trypanosoma cruzi was evaluated in vitro against epimastigote and trypomastigotes and in vivo against trypomastigotes. In active extracts, toxicity was evaluated by Artemia salina nauplii, oral acute toxicity (1-5 g/kg) and oral and intraperitoneal subacute toxicity in mice (500 mg/kg). From the plants screened, six showed activity (Neurolaena lobata and Solanum americanum; in vitro or in vivo activity was shown by Acalypha guatemalensis, Petiveria alliacea and Tridax procumbens. Toxicity studies showed that extracts from S. americanum are toxic to A. salina (aqueous, 160 ppm). None showed acute or oral toxicity to mice; S. americanum showed intraperitoneal subacute toxicity.

  1. [Antimicrobial susceptibility patterns of Gram-negative bacteria isolated in urinary tract infections in Venezuela: Results of the SMART study 2009-2012].

    Science.gov (United States)

    Guevara, Napoleón; Guzmán, Manuel; Merentes, Altagracia; Rizzi, Adele; Papaptzikos, Juana; Rivero, Narlesky; Oranges, Carmela; Vlllarroel, Héctor; Limas, Yoxsivell

    2015-12-01

    Antimicrobial resistance of pathogens causing urinary tract infection (UTI) is a growing problem, which complicates their effective treatment. Surveillance is needed to guide appropriate empiric therapy. to describe the susceptibility patterns of Gram-negative bacteria isolated of patients with UTI to twelve antibiotics as part of the Study for Monitoring Antimicrobial Resistance Trends in Venezuela. Between 2009-2012 a total of 472 Gram-negative bacteria were isolated from hospitalized patients with UTI. The isolates were sent to Central Laboratory (Central Laboratory of International Health Management Associates) to confirm their identification, and to make susceptibility testing as recommended by the Clinical and Laboratory Standards Institute. Enterobacteriacea comprised 96.6% of the total, where Escherichia coli (76.9%) and Klebsiella pneumoniae (10.6%) were the most frequent. Extended-spectrum β-lactamases (ESBL) was detected in 21.6% of isolates. Top antimicrobial activity were ertapenem, imipenem, and amikacin (> 90.0%), slightly lower for amikacin (85.1%) in ESBL-producing strains. Resistance rates to fluoroquinolones and ampicillin/sulbactam were high (40 y 64%, respectively). These data suggest a necessary revision of the therapeutic regimens for the empirical treatment of UTI in Venezuela.

  2. Fungal infection control by garlic extracts (Allium sativum L.) and modulation of peritoneal macrophages activity in murine model of sporotrichosis.

    Science.gov (United States)

    Burian, J P; Sacramento, L V S; Carlos, I Z

    2017-11-01

    Garlic (Allium sativum L.) is grown all over the world as seasoning and medicinal vegetable since 3,000 BC. Allicin is the main component of garlic, being attributed to it the most of its biological activities, such as bactericidal, antifungal and antiviral actions. However, other compounds of garlic present antioxidant, hypocholesterolemic, vasodilator activities, protective action against different types of cancer, and immunomodulatory. Fungal infections are important causes of morbidity and mortality in people mainly in immunosuppressed ones. Sporothrix schenckii, the causing agent of Sporotrichosis (most common subcutaneous mycosis in Latin America), is dimorphic fungus, of saprophytic life in soil or plants, infecting people and animals mainly through skin injuries and bruises. The main of this work was to evaluate the influence of garlic consuming on immune modulation of healthy and infected Swiss mice in induced way by S. schenckii, since these animals functioning of peritoneal macrophages as well as the nitric oxide and cytokines' production (IL-1β, IL-10 and IL-12) and to evaluate the antifungal potential of garlic with S. schenckii through minimum inhibitory concentration test and colony-forming units. The results showed that garlic offers antifungal potential with S. schenckii. The oral taking of garlic extracts influences the releasing of cytokines by macrophages, regular consuming shows anti-inflammatory effect, and its acute use may take to an inflammatory response. Mice that consumed garlic responded more effectively to fight against the infection.

  3. Fungal infection control by garlic extracts (Allium sativum L. and modulation of peritoneal macrophages activity in murine model of sporotrichosis

    Directory of Open Access Journals (Sweden)

    J. P. Burian

    2017-05-01

    Full Text Available Abstract Garlic (Allium sativum L. is grown all over the world as seasoning and medicinal vegetable since 3,000 BC. Allicin is the main component of garlic, being attributed to it the most of its biological activities, such as bactericidal, antifungal and antiviral actions. However, other compounds of garlic present antioxidant, hypocholesterolemic, vasodilator activities, protective action against different types of cancer, and immunomodulatory. Fungal infections are important causes of morbidity and mortality in people mainly in immunosuppressed ones. Sporothrix schenckii, the causing agent of Sporotrichosis (most common subcutaneous mycosis in Latin America, is dimorphic fungus, of saprophytic life in soil or plants, infecting people and animals mainly through skin injuries and bruises. The main of this work was to evaluate the influence of garlic consuming on immune modulation of healthy and infected Swiss mice in induced way by S. schenckii, since these animals functioning of peritoneal macrophages as well as the nitric oxide and cytokines’ production (IL-1β, IL-10 and IL-12 and to evaluate the antifungal potential of garlic with S. schenckii through minimum inhibitory concentration test and colony-forming units. The results showed that garlic offers antifungal potential with S. schenckii. The oral taking of garlic extracts influences the releasing of cytokines by macrophages, regular consuming shows anti-inflammatory effect, and its acute use may take to an inflammatory response. Mice that consumed garlic responded more effectively to fight against the infection.

  4. period-Regulated Feeding Behavior and TOR Signaling Modulate Survival of Infection.

    Science.gov (United States)

    Allen, Victoria W; O'Connor, Reed M; Ulgherait, Matthew; Zhou, Clarice G; Stone, Elizabeth F; Hill, Vanessa M; Murphy, Keith R; Canman, Julie C; Ja, William W; Shirasu-Hiza, Mimi M

    2016-01-25

    Most metazoans undergo dynamic, circadian-regulated changes in behavior and physiology. Currently, it is unknown how circadian-regulated behavior impacts immunity against infection. Two broad categories of defense against bacterial infection are resistance, control of microbial growth, and tolerance, control of the pathogenic effects of infection. Our study of behaviorally arrhythmic Drosophila circadian period mutants identified a novel link between nutrient intake and tolerance of infection with B. cepacia, a bacterial pathogen of rising importance in hospital-acquired infections. We found that infection tolerance in wild-type animals is stimulated by acute exposure to dietary glucose and amino acids. Glucose-stimulated tolerance was induced by feeding or direct injection; injections revealed a narrow window for glucose-stimulated tolerance. In contrast, amino acids stimulated tolerance only when ingested. We investigated the role of a known amino-acid-sensing pathway, the TOR (Target of Rapamycin) pathway, in immunity. TORC1 is circadian regulated and inhibition of TORC1 decreased resistance, as in vertebrates. Surprisingly, inhibition of the less well-characterized TOR complex 2 (TORC2) dramatically increased survival, through both resistance and tolerance mechanisms. This work suggests that dietary intake on the day of infection by B. cepacia can make a significant difference in long-term survival. We further demonstrate that TOR signaling mediates both resistance and tolerance of infection and identify TORC2 as a novel potential therapeutic target for increasing survival of infection. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Prevalence of Device-associated Nosocomial Infections Caused By Gram-negative Bacteria in a Trauma Intensive Care Unit in Libya

    Directory of Open Access Journals (Sweden)

    Abdulaziz Zorgani

    2015-07-01

    Full Text Available Objectives: Device-associated nosocomial infections (DANIs have a major impact on patient morbidity and mortality. Our study aimed to determine the distribution rate of DANIs and causative agents and patterns of antibiotic resistance in the trauma-surgical intensive care unit (ICU. Methods: Our study was conducted at Abusalim Trauma Hospital in Tripoli, Libya. All devices associated with nosocomial infections, including central venous catheters (CVC, endotracheal tubes (ETT, Foley’s urinary catheters, chest tubes, nasogastric tubes (NGT, and tracheostomy tubes, were removed aseptically and examined for Gram-negative bacteria (GNB. Results: During a one-year study period, 363 patients were hospitalized; the overall mortality rate was 29%. A total of 79 DANIs were identified, the most common site of infection was ETT (39.2%, followed by urinary catheters (19%, NGTs (18%, tracheostomy tubes (11%, CVCs (10%, and chest tubes (3%. The most frequently isolated organisms were Klebsiella pneumonia, Acinetobacter baumannii, and Pseudomonas aeruginosa (30%, 20%, and 14%, respectively. Extremely high resistance rates were observed among GNB to ampicillin (99%, cefuroxime (95%, amoxicillin-clavulante (92%, and nitrofurantoin (91%. Lower levels of resistance were exhibited to amikacin (38%, imipenem (38%, and colistin (29%. About 39% of the isolates were defined as multi-drug resistant (MDR. Overall, extended spectrum β-lactmase producers were expressed in 39% of isolates mainly among K. pneumonia (88%. A. baumannii isolates exhibited extremely high levels of resistance to all antibiotics except colistin (100% sensitive. In addition, 56.3% of A. baumannii isolates were found to be MDR. P. aeruginosa isolates showed 46%–55% effectiveness to anti-pseudomonas antibiotics. Conclusion: High rates of DANI’s and the emergence of MDR organisms poses a serious threat to patients. There is a need to strengthen infection control within the ICU environment

  6. The effect of gamma-radiation on the microbiological alterations of swine liquid manure artifically infected with bacteria

    International Nuclear Information System (INIS)

    Gleria, M. di; Beczassy, Gy-ne.; Szemeredy, Gy.

    1979-01-01

    In the present work an account on the use of ionizing radiation for disinfection of swine liquid manure is given. The most common representatives of pathogenic and facultative-pathogenic microorganisms in swine liquid manure have been irradiated and their sensitivity to different doses of 60 Co gamma radiation has been examined. Most of the studied bacteria were killed by a radiation dose of 4 kGy. However, a very high resistance has been found in the cases of saprophytic and pathogenic mycobacteria and spore containing Clostridium perfringens. These microorganisms required a lethal dose of 5 and 7 kGy, respectively. After radiation treatment the liquid manure can be used in agriculture for irrigation and it can be recycled to the stall cleaning procedures. (author)

  7. Does nuclear tissue infected with bacteria following disc herniations lead to Modic changes in the adjacent vertebrae?

    DEFF Research Database (Denmark)

    Albert, H. B.; Lambert, Peter; Rollason, Jess

    2013-01-01

    PURPOSE: To investigate the prevalence of infected herniated nucleus material in lumbar disc herniations and to determine if patients with an anaerobic infected disc are more likely to develop Modic change (MC) (bone oedema) in the adjacent vertebrae after the disc herniation. MCs (bone oedema...... due to cytokine and propionic acid production. METHODS: Patients undergoing primary surgery at a single spinal level for lumbar disc herniation with an MRI-confirmed lumbar disc herniation, where the annular fibres were penetrated by visible nuclear tissue, had the nucleus material removed. Stringent...... antiseptic sterile protocols were followed. RESULTS: Sixty-one patients were included, mean age 46.4 years (SD 9.7), 27 % female. All patients were immunocompetent. No patient had received a previous epidural steroid injection or undergone previous back surgery. In total, microbiological cultures were...

  8. Development of aptamers for use as radiopharmaceuticals in the bacterial infection identification; Desenvolvimento de aptameros especificos para aplicacao como radiofarmacos na identificacao de bacterias

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Ieda Mendes

    2013-08-01

    The difficulty in early detection of specific foci caused by bacteria in the bacterial infection has raised the need to search for new techniques for this purpose, since these foci require prolonged treatment with antibiotics and in some cases even drainage or, if applicable, removal of prostheses or grafts. Detection of bacterial infections by scintigraphy had the advantage that a whole body image could be obtained, since specific tracers were available. This study aims to obtain aptamers specific for bacteria identification for future use as radiopharmaceutical. The SELEX (Systematic Evolution of Ligands by Exponential Enrichment) methodology can generate oligonucleotides (aptamers) that are able to bind with high affinity and specificity to a specific target, from small molecules to complex proteins, by using rounds of enrichment and amplification. Aptamers can be labeled with different radionucleotides such as {sup 99}mTc, {sup 18}F and {sup 32}P. In this study, aptamers anti-peptidoglycan, the main component of the bacterial outer cell wall, were obtained through SELEX. Whole cells of Staphylococcus aureus were also used to perform the SELEX to cells (cell-SELEX). The selection of aptamers was performed by two different procedures (A and B). The A process has been accomplished by 15 SELEX rounds in which the separation of the oligonucleotides bound to the peptidoglycan of unbound ones was performed by filtration. In the B process 15 SELEX rounds were performed using the centrifugation for this separation, followed by 5 rounds cell-SELEX. The SELEX started with a pool of ssDNA (single stranded DNA). For A process, initially a library of ssDNA was incubated with peptidoglycan and the amplification of oligonucleotides that were able to bind to peptidoglycan was performed by PCR (Polymerase Chain Reation). The amplified oligonucleotides were again incubated with peptidoglycan, amplified and purified. At the end of 15 selection rounds the selected oligonucleotides

  9. The Use of Recombinant Feline Interferon Omega Therapy as an Immune-Modulator in Cats Naturally Infected with Feline Immunodeficiency Virus: New Perspectives

    Directory of Open Access Journals (Sweden)

    Rodolfo Oliveira Leal

    2016-10-01

    Full Text Available Type I interferons (IFNs are well-known cytokines that, among their main functions, are key components of the host immune response against viral infections. Due to its immune modulation properties, they are commonly used in the therapeutic approach of various retroviral infections, namely human immunodeficiency virus (HIV and feline immunodeficiency virus (FIV. In HIV infection, it has been shown that IFN therapy limits early viral replication, particularly useful on post-exposure prophylaxis. In veterinary medicine, recombinant feline interferon omega (rFeIFN-ω was the first interferon licensed for use in cats. Several studies have recently shown that this compound seems to stimulate the innate immunity, decreasing clinical signs and co-infections in naturally FIV-infected cats. More than summarizing the main conclusions about rFeIFN-ω in cats, this review emphasizes the immune-modulation properties of IFN therapy, opening new perspectives for its use in retroviral infections. Either in FIV-infected cats or in HIV individuals, type I IFNs seem to induce an innate immune-modulation and should not be overlooked as a therapeutic option in retroviral infections.

  10. The Use of Recombinant Feline Interferon Omega Therapy as an Immune-Modulator in Cats Naturally Infected with Feline Immunodeficiency Virus: New Perspectives.

    Science.gov (United States)

    Leal, Rodolfo Oliveira; Gil, Solange

    2016-10-27

    Type I interferons (IFNs) are well-known cytokines that, among their main functions, are key components of the host immune response against viral infections. Due to its immune modulation properties, they are commonly used in the therapeutic approach of various retroviral infections, namely human immunodeficiency virus (HIV) and feline immunodeficiency virus (FIV). In HIV infection, it has been shown that IFN therapy limits early viral replication, particularly useful on post-exposure prophylaxis. In veterinary medicine, recombinant feline interferon omega (rFeIFN-ω) was the first interferon licensed for use in cats. Several studies have recently shown that this compound seems to stimulate the innate immunity, decreasing clinical signs and co-infections in naturally FIV-infected cats. More than summarizing the main conclusions about rFeIFN-ω in cats, this review emphasizes the immune-modulation properties of IFN therapy, opening new perspectives for its use in retroviral infections. Either in FIV-infected cats or in HIV individuals, type I IFNs seem to induce an innate immune-modulation and should not be overlooked as a therapeutic option in retroviral infections.

  11. Modulation of flavonoid biosynthetic pathway genes and anthocyanins due to virus infection in grapevine (Vitis vinifera L. leaves

    Directory of Open Access Journals (Sweden)

    Gutha Linga R

    2010-08-01

    symptomatic leaves when compared to virus-free green leaves. Conclusions The results, the first example to our knowledge, showed that modulation of the flavonoid biosynthetic pathway occurred in GLRaV-3-infected leaves of a red-fruited wine grape cultivar (cv. Merlot leading to de novo synthesis of two classes of anthocyanins. These anthocyanins have contributed to the expression of reddish-purple color of virus-infected grapevine leaves exhibiting GLRD symptoms.

  12. Modulation of the immune response to Mycobacterium tuberculosis during malaria/M. tuberculosis co‐infection

    Science.gov (United States)

    Onyenekwe, C. C.; Martinez‐Pomares, L.; Flynn, R.; Singh, S.; Amilo, G. I.; Agbakoba, N. R.; Okoye, J. O.

    2016-01-01

    Summary Tuberculosis (TB) causes significant morbidity and mortality on a global scale. The African region has 24% of the world's TB cases. TB overlaps with other infectious diseases such as malaria and HIV, which are also highly prevalent in the African region. TB is a leading cause of death among HIV‐positive patients and co‐infection with HIV and TB has been described as a syndemic. In view of the overlapping epidemiology of these diseases, it is important to understand the dynamics of the immune response to TB in the context of co‐infection. We investigated the cytokine response to purified protein derivative (PPD) in peripheral blood mononuclear cells from TB patients co‐infected with HIV or malaria and compared it to that of malaria‐ and HIV‐free TB patients. A total of 231 subjects were recruited for this study and classified into six groups; untreated TB‐positive, TB positive subjects on TB drugs, TB‐ and HIV‐positive, TB‐ and malaria‐positive, latent TB and apparently healthy control subjects. Our results demonstrate maintenance of interferon (IFN)‐γ production in HIV and malaria co‐infected TB patients in spite of lower CD4 counts in the HIV‐infected cohort. Malaria co‐infection caused an increase in the production of the T helper type 2 (Th2)‐associated cytokine interleukin (IL)‐4 and the anti‐inflammatory cytokine IL‐10 in PPD‐stimulated cultures. These results suggest that malaria co‐infection diverts immune response against M. tuberculosis towards a Th‐2/anti‐inflammatory response which might have important consequences for disease progression. PMID:27577087

  13. Modulation of allergic immune responses by mucosal application of recombinant lactic acid bacteria producing the major birch pollen allergen Bet v 1.

    Science.gov (United States)

    Daniel, C; Repa, A; Wild, C; Pollak, A; Pot, B; Breiteneder, H; Wiedermann, U; Mercenier, A

    2006-07-01

    Probiotic lactic acid bacteria (LAB) are able to modulate the host immune system and clinical trials have demonstrated that specific strains have the capacity to reduce allergic symptoms. Therefore, we aimed to evaluate the potential of recombinant LAB producing the major birch pollen allergen Bet v 1 for mucosal vaccination against birch pollen allergy. Recombinant Bet v 1-producing Lactobacillus plantarum and Lactococcus lactis strains were constructed. Their immunogenicity was compared with purified Bet v 1 by subcutaneous immunization of mice. Intranasal application of the live recombinant strains was performed to test their immunomodulatory potency in a mouse model of birch pollen allergy. Bet v 1 produced by the LAB was recognized by monoclonal anti-Bet v 1 and IgE antibodies from birch pollen-allergic patients. Systemic immunization with the recombinant strains induced significantly lower IgG1/IgG2a ratios compared with purified Bet v 1. Intranasal pretreatment led to reduced allergen-specific IgE vs enhanced IgG2a levels and reduced interleukin (IL)-5 production of splenocytes in vitro, indicating a shift towards non-allergic T-helper-1 (Th1) responses. Airway inflammation, i.e. eosinophils and IL-5 in lung lavages, was reduced using either Bet v 1-producing or control strains. Allergen-specific secretory IgA responses were enhanced in lungs and intestines after pretreatment with only the Bet v 1-producing strains. Mucosal vaccination with live recombinant LAB, leading to a shift towards non-allergic immune responses along with enhanced allergen-specific mucosal IgA levels offers a promising approach to prevent systemic and local allergic immune responses.

  14. Biotherapeutic effects of probiotic bacteria on candidiasis in immunodeficient mice.

    Science.gov (United States)

    Wagner, R D; Pierson, C; Warner, T; Dohnalek, M; Farmer, J; Roberts, L; Hilty, M; Balish, E

    1997-10-01

    Four species of probiotic bacteria were assessed for their capacities to protect athymic bg/bg-nu/nu and euthymic bg/bg-nu/+ mice from mucosal and systemic candidiasis. Each bacterial species and Candida albicans colonized the gastrointestinal tracts of both strains of mice. The presence of probiotic bacteria (Lactobacillus acidophilus, Lactobacillus reuteri, Lactobacillus casei GG, or Bifidobacterium animalis) in the gastrointestinal tracts prolonged the survival of adult and neonatal bg/bg-nu/nu mice compared to that of isogenic mice colonized with C. albicans alone. The incidence of systemic candidiasis in bg/bg-nu/nu mice was significantly reduced by each of the four probiotic bacterial species. The numbers of C. albicans present in the alimentary tracts of euthymic bg/bg-nu/+ mice were significantly reduced by L. casei GG and B. animalis. None of the probiotic bacteria species completely prevented mucosal candidiasis, but B. animalis reduced its incidence and severity. Probiotic bacteria also modulated antibody- and cell-mediated immune responses to C. albicans. The prolonged survival of mice, decreased severity of mucosal and systemic candidiasis, modulation of immune responses, decreased number of C. albicans in the alimentary tract, and reduced numbers of orogastric infections demonstrated not only that probiotic bacteria have biotherapeutic potential for prophylaxis against and therapy of this fungal disease but also that probiotic bacteria protect mice from candidiasis by a variety of immunologic (thymic and extrathymic) and nonimmunologic mechanisms in this model.

  15. Comparative study of CXC chemokines modulation in brown trout (Salmo trutta) following infection with a bacterial or viral pathogen.

    Science.gov (United States)

    Gorgoglione, Bartolomeo; Zahran, Eman; Taylor, Nick G H; Feist, Stephen W; Zou, Jun; Secombes, Christopher J

    2016-03-01

    Chemokine modulation in response to pathogens still needs to be fully characterised in fish, in view of the recently described novel chemokines present. This paper reports the first comparative study of CXC chemokine genes transcription in salmonids (brown trout), with a particular focus on the fish specific CXC chemokines (CXCL_F). Adopting new primer sets, optimised to specifically target mRNA, a RT-qPCR gene screening was carried out. Constitutive gene expression was assessed first in six tissues from SPF brown trout. Transcription modulation was next investigated in kidney and spleen during septicaemic infection induced by a RNA virus (Viral Haemorrhagic Septicaemia virus, genotype Ia) or by a Gram negative bacterium (Yersinia ruckeri, ser. O1/biot. 2). From each target organ specific pathogen burden, measured detecting VHSV-glycoprotein or Y. ruckeri 16S rRNA, and IFN-γ gene expression were analysed for their correlation to chemokine transcription. Both pathogens modulated CXC chemokine gene transcript levels, with marked up-regulation seen in some cases, and with both temporal and tissue specific effects apparent. For example, Y. ruckeri strongly induced chemokine transcription in spleen within 24h, whilst VHS generally induced the largest increases at 3d.p.i. in both tissues. This study gives clues to the role of the novel CXC chemokines, in comparison to the other known CXC chemokines in salmonids. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Infection of neuroblastoma cells by rabies virus is modulated by the virus titer.

    Science.gov (United States)

    Fuoco, Natalia Langenfeld; Dos Ramos Silva, Sandriana; Fernandes, Elaine Raniero; Luiz, Fernanda Guedes; Ribeiro, Orlando Garcia; Katz, Iana Suly Santos

    2018-01-01

    Rabies is a lethal viral infection that can affect almost all mammals, including humans. To better understand the replication of Rabies lyssavirus, we investigated if the viral load in brains naturally infected with rabies influences viral internalization and viral growth kinetics in neuroblastoma cells, and if the viral load affects mortality in mice after intradermal infection. We noted that high initial viral loads in brains (group II) were unfavourable for increasing viral titers during serial passages in neuroblastoma cells when compared to low initial viral loads in brains (group I). In addition, group I strains showed higher viral growth and enhanced internalization efficiency in neuroblastoma cells than group II strains. However, we observed that the dominant virus subpopulation in group II promoted efficient viral infection in the central nervous system in the new host, providing a selective advantage to the virus. Our data indicate that rabies infection in animal models depends on not only the virus strain but also the amount of virus. This study may serve as a basis for understanding the biologic proprieties of Rabies lyssavirus strains with respect to the effects on viral replication and the impact on pathogenesis, improving virus yields for use in vaccine development. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Modulation of neuronal proteome profile in response to Japanese encephalitis virus infection.

    Science.gov (United States)

    Sengupta, Nabonita; Ghosh, Sourish; Vasaikar, Suhas V; Gomes, James; Basu, Anirban

    2014-01-01

    In this study we have reported the in vivo proteomic changes during Japanese Encephalitis Virus (JEV) infection in combination with in vitro studies which will help in the comprehensive characterization of the modifications in the host metabolism in response to JEV infection. We performed a 2-DE based quantitative proteomic study of JEV-infected mouse brain as well as mouse neuroblastoma (Neuro2a) cells to analyze the host response to this lethal virus. 56 host proteins were found to be differentially expressed post JEV infection (defined as exhibiting ≥ 1.5-fold change in protein abundance upon JEV infection). Bioinformatics analyses were used to generate JEV-regulated host response networks which reported that the identified proteins were found to be associated with various cellular processes ranging from intracellular protein transport, cellular metabolism and ER stress associated unfolded protein response. JEV was found to invade the host protein folding machinery to sustain its survival and replication inside the host thereby generating a vigorous unfolded protein response, subsequently triggering a number of pathways responsible for the JEV associated pathologies. The results were also validated using a human cell line to correlate them to the human response to JEV. The present investigation is the first report on JEV-host interactome in in vivo model and will be of potential interest for future antiviral research in this field.

  18. Screening of probiotic bacteria and its role on artificial infection of Vibrio harvey in white shrimp (Litopenaeus vannamei

    Directory of Open Access Journals (Sweden)

    . Sukenda

    2007-07-01

    Full Text Available Probiotic was screened from 28 strains of normal bacterial flora isolated from rearing water in a Litopenaeus vannamei farm based on its inhibitory activity against the growth of Vibrio harveyi.  Antibacterial activity was also tested in vivo to V. harveyi in L. vannamei.  The result showed that  the probiotic has a antibacterial effect on V. harveyi.  The in vivo test showed that shrimps injected with probiotic previously before challenged with V. harveyi has survival higher than control.  Probiotic isolate was suspected as Vibrio furnissi. Keywords:  biocontrol, inhibitory activity, Vibrio furnissi, Vibrio harveyi, Litopenaeus vannamei   AbstraK Bakteri probiotik ditapis dari 28 strain bacteria flora yang diisolasi dari air pemeliharaan udang vaname Litopenaeus vannamei berdasarkan aktivitas penghambatannya terhadap pertumbuhan Vibrio harveyi.  Aktivitas bakteri probiotik juga diuji secara in vivo terhadap V. harveyi pada udang putih.  Hasil penelitian menunjukkan bahwa bakteri probiotik isolat memiliki kemampuan antibakteria terhadap V. harveyi.  Uji in vivo menunjukkan bahwa udang yang diinjeksi probiotik sebelum diuji tantang dengan V. harveyi memiliki kelangsungan hidup lebih tinggi daripada kontrol.  Isolat probiotik tersebut diduga adalah Vibrio furnissi. Kata kunci:  biokontrol, aktivitas penghambatan, Vibrio furnissi, Vibrio harveyi, Litopenaeus vannamei

  19. Subversion of the cytoskeleton by intracellular bacteria: lessons from Listeria, Salmonella, and Vibrio

    Science.gov (United States)

    de Souza Santos, Marcela; Orth, Kim

    2018-01-01

    Summary Entry into host cells and intracellular persistence by invasive bacteria are tightly coupled to the ability of the bacterium to disrupt the eukaryotic cytoskeletal machinery. Herein we review the main strategies used by three intracellular pathogens to harness key modulators of the cytoskeleton. Two of these bacteria, namely Listeria monocytogenes and Salmonella enterica serovar Typhimurium, exhibit quite distinct intracellular lifestyles, and therefore, provide a comprehensive panel for the understanding of the intricate bacteria-cytoskeleton interplay during infections. The emerging intracellular pathogen Vibrio parahaemolyticus is depicted as a developing model for the uncovering of novel mechanisms used to hijack the cytoskeleton. PMID:25440316

  20. Bacteria, the endoplasmic reticulum and the unfolded protein response: friends or foes?

    Science.gov (United States)

    Celli, Jean; Tsolis, Renée M

    2015-02-01

    The unfolded protein response (UPR) is a cytoprotective response that is aimed at restoring cellular homeostasis following physiological stress exerted on the endoplasmic reticulum (ER), which also invokes innate immune signalling in response to invading microorganisms. Although it has been known for some time that the UPR is modulated by various viruses, recent evidence indicates that it also has multiple roles during bacterial infections. In this Review, we describe how bacteria interact with the ER, including how bacteria induce the UPR, how subversion of the UPR promotes bacterial proliferation and how the UPR contributes to innate immune responses against invading bacteria.

  1. Antibacterial activity of Valeriana jatamansi against extended-spectrum β-lactamase producing Gramnegative bacteria causing urinary tract infections

    Directory of Open Access Journals (Sweden)

    Babar Habib

    2016-10-01

    Full Text Available Objective: To find out the antibacterial activity of Valeriana jatamansi (V. jatamansi rhizomes against the extended-spectrum β-lactamases (ESBLs producing isolates of Enterobacteriaceae family. Methods: Confirmation of ESBLs producing Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae and Hafnia alvei isolated from urinary tract infections was performed by double disc diffusion assay. Antimicrobial susceptibility of all ESBLs producing isolates was determined by disc diffusion method following guidelines of Clinical and Laboratory Standards Institute. Successive extraction of rhizomes of V. jatamansi was performed with hexane, chloroform and methanol using Soxhelt apparatus. These extracts were tested against the ESBLs producing isolates using well diffusion method. Results: Hexane extract showed significant results as compared to chloroform and methanol extracts with the maximum zone of inhibition (21 mm while ciprofloxacin and amikacin were used as standard drugs. Conclusions: Findings of the study suggested that hexane extract of V. jatamansi can be used in combination with other antibiotics as alternative treatment for urinary tract infections caused by ESBLs producing strains of Enterobacteriaceae.

  2. In vitro susceptibility testing to antimicrobial agents of urinary tract infection bacteria in women: a 5-year retrospective study

    Directory of Open Access Journals (Sweden)

    Laura Melgarejo

    2017-06-01

    Full Text Available Introduction: The growing resistance rates of urinary pathogens represent a serious problem. The aim of this study was to analyze the etiology of community-acquired urinary tract infections, their first-line antimicrobial resistance and the presence of extended-spectrum beta-lactamases (ESBL in gram negative bacilli. Methods: The study was conducted between January 2011 and December 2015 using data from the Microbiology Laboratory at the teaching hospital Hospital de Clínicas, which belongs to the National University of Asunción. Results: A total of 1957 urinary pathogens were found in women. Escherichia coli was the most commonly isolated bacterium (57%, followed by Klebsiella pneumoniae (11% and Streptococcus agalactiae (2%, Staphylococcus saprophyticus (2% and Proteus mirabilis (2%. The resistance rates of Escherichia coli were the following: to trimetoprim-sulfametoxazol, 43%; to ciprofloxacin, 32%; to ampicilin/sulbactam, 32%; to cefotaxime, 13 %; to piperacillin/tazobactam, 8%; nitrofurantoin, 2%, whereas it did not show resistance to meropenem during this period. Extended-spectrum beta-lactamases were produced by 11% of the E. coli isolates and 30% of the Klebsiella pneumoniae isolates. Conclusions: The resistance and cross-resistance rates found in this study pose a serious problem which compels the continuous assessment of the empirical therapy for urinary tract infections at this hospital.

  3. Natural blood feeding and temperature shift modulate the global transcriptional profile of Rickettsia rickettsii infecting its tick vector.

    Directory of Open Access Journals (Sweden)

    Maria Fernanda B M Galletti

    Full Text Available Rickettsia rickettsii is an obligate intracellular tick-borne bacterium that causes Rocky Mountain Spotted Fever (RMSF, the most lethal spotted fever rickettsiosis. When an infected starving tick begins blood feeding from a vertebrate host, R. rickettsii is exposed to a temperature elevation and to components in the blood meal. These two environmental stimuli have been previously associated with the reactivation of rickettsial virulence in ticks, but the factors responsible for this phenotype conversion have not been completely elucidated. Using customized oligonucleotide microarrays and high-throughput microfluidic qRT-PCR, we analyzed the effects of a 10°C temperature elevation and of a blood meal on the transcriptional profile of R. rickettsii infecting the tick Amblyomma aureolatum. This is the first study of the transcriptome of a bacterium in the genus Rickettsia infecting a natural tick vector. Although both stimuli significantly increased bacterial load, blood feeding had a greater effect, modulating five-fold more genes than the temperature upshift. Certain components of the Type IV Secretion System (T4SS were up-regulated by blood feeding. This suggests that this important bacterial transport system may be utilized to secrete effectors during the tick vector's blood meal. Blood feeding also up-regulated the expression of antioxidant enzymes, which might correspond to an attempt by R. rickettsii to protect itself against the deleterious effects of free radicals produced by fed ticks. The modulated genes identified in this study, including those encoding hypothetical proteins, require further functional analysis and may have potential as future targets for vaccine development.

  4. Recognizing the SINEs of Infection: Regulation of Retrotransposon Expression and Modulation of Host Cell Processes

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    William Dunker

    2017-12-01

    Full Text Available Short interspersed elements (SINEs are a family of retrotransposons evolutionarily derived from cellular RNA polymerase III transcripts. Over evolutionary time, SINEs have expanded throughout the human genome and today comprise ~11% of total chromosomal DNA. While generally transcriptionally silent in healthy somatic cells, SINE expression increases during a variety of types of stresses, including DNA virus infection. The relevance of SINE expression to viral infection was largely unexplored, however, recent years have seen great progress towards defining the impact of SINE expression on viral replication and host gene expression. Here we review the origin and diversity of SINE elements and their transcriptional control, with an emphasis on how their expression impacts host cell biology during viral infection.

  5. C. difficile Infection

    Science.gov (United States)

    ... Patients Home / Digestive Health Topic / C. Difficile Infection C. Difficile Infection Basics Overview Diarrhea is a frequent ... that change the normal colon bacteria allowing the C. difficile bacteria to grow and produce its toxins. ...

  6. Horse species symposium: a novel approach to monitoring pathogen progression during uterine and placental infection in the mare using bioluminescence imaging technology and lux-modified bacteria.

    Science.gov (United States)

    Ryan, P L; Christiansen, D L; Hopper, R M; Walters, F K; Moulton, K; Curbelo, J; Greene, J M; Willard, S T

    2011-05-01

    Uterine and placental infections are the leading cause of abortion, stillbirth, and preterm delivery in the mare. Whereas uterine and placental infections in women have been studied extensively, a comprehensive examination of the pathogenic processes leading to this unsatisfactory pregnancy outcome in the mare has yet to be completed. Most information in the literature relating to late-term pregnancy loss in mares is based on retrospective studies of clinical cases submitted for necropsy. Here we report the development and application of a novel approach, whereby transgenically modified bacteria transformed with lux genes of Xenorhabdus luminescens or Photorhabdus luminescens origin and biophotonic imaging are utilized to better understand pathogen-induced preterm birth in late-term pregnant mares. This technology uses highly sensitive bioluminescence imaging camera systems to localize and monitor pathogen progression during tissue invasion by measuring the bioluminescent signatures emitted by the lux-modified pathogens. This method has an important advantage in that it allows for the potential tracking of pathogens in vivo in real time and over time, which was hitherto impossible. Although the application of this technology in domestic animals is in its infancy, investigators were successful in identifying the fetal lungs, sinuses, nares, urinary, and gastrointestinal systems as primary tissues for pathogen invasion after experimental infection of pregnant mares with lux-modified Escherichia coli. It is important that pathogens were not detected in other vital organs, such as the liver, brain, and cardiac system. Such precision in localizing sites of pathogen invasion provides potential application for this novel approach in the development of more targeted therapeutic interventions for pathogen-related diseases in the equine and other domestic species.

  7. Leishmania infection modulates beta-1 integrin activation and alters the kinetics of monocyte spreading over fibronectin

    Science.gov (United States)

    Figueira, Cláudio Pereira; Carvalhal, Djalma Gomes Ferrão; Almeida, Rafaela Andrade; Hermida, Micely d’ El-Rei; Touchard, Dominique; Robert, Phillipe; Pierres, Anne; Bongrand, Pierre; dos-Santos, Washington LC

    2015-01-01

    Contact with Leishmania leads to a decreases in mononuclear phagocyte adherence to connective tissue. In this work, we studied the early stages of bond formation between VLA4 and fibronectin, measured the kinetics of membrane alignment and the monocyte cytoplasm spreading area over a fibronectin-coated surface, and studied the expression of high affinity integrin epitope in uninfected and Leishmania-infected human monocytes. Our results show that the initial VLA4-mediated interaction of Leishmania-infected monocyte with a fibronectin-coated surface is preserved, however, the later stage, leukocyte spreading over the substrate is abrogated in Leishmania-infected cells. The median of spreading area was 72 [55–89] μm2 for uninfected and 41 [34–51] μm2 for Leishmania-infected monocyte. This cytoplasm spread was inhibited using an anti-VLA4 blocking antibody. After the initial contact with the fibronectrin-coated surface, uninfected monocyte quickly spread the cytoplasm at a 15 μm2 s−1 ratio whilst Leishmania-infected monocytes only made small contacts at a 5.5 μm2 s−1 ratio. The expression of high affinity epitope by VLA4 (from 39 ± 21% to 14 ± 3%); and LFA1 (from 37 ± 32% to 18 ± 16%) molecules was reduced in Leishmania-infected monocytes. These changes in phagocyte function may be important for parasite dissemination and distribution of lesions in leishmaniasis. PMID:26249106

  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. Complex modulation of the Aedes aegypti transcriptome in response to dengue virus infection.

    Science.gov (United States)

    Bonizzoni, Mariangela; Dunn, W Augustine; Campbell, Corey L; Olson, Ken E; Marinotti, Osvaldo; James, Anthony A

    2012-01-01

    Dengue fever is the most important arboviral disease world-wide, with Aedes aegypti being the major vector. Interactions between the mosquito host and dengue viruses (DENV) are complex and vector competence varies among geographically-distinct Ae. aegypti populations. Additionally, dengue is caused by four antigenically-distinct viral serotypes (DENV1-4), each with multiple genotypes. Each virus genotype interacts differently with vertebrate and invertebrate hosts. Analyses of alterations in mosquito transcriptional profiles during DENV infection are expected to provide the basis for identifying networks of genes involved in responses to viruses and contribute to the molecular-genetic understanding of vector competence. In addition, this knowledge is anticipated to support the development of novel disease-control strategies. RNA-seq technology was used to assess genome-wide changes in transcript abundance at 1, 4 and 14 days following DENV2 infection in carcasses, midguts and salivary glands of the Ae. aegypti Chetumal strain. DENV2 affected the expression of 397 Ae. aegypti genes, most of which were down-regulated by viral infection. Differential accumulation of transcripts was mainly tissue- and time-specific. Comparisons of our data with other published reports reveal conservation of functional classes, but limited concordance of specific mosquito genes responsive to DENV2 infection. These results indicate the necessity of additional studies of mosquito-DENV interactions, specifically those focused on recently-derived mosquito strains with multiple dengue virus serotypes and genotypes.

  10. Complex modulation of the Aedes aegypti transcriptome in response to dengue virus infection.

    Directory of Open Access Journals (Sweden)

    Mariangela Bonizzoni

    Full Text Available Dengue fever is the most important arboviral disease world-wide, with Aedes aegypti being the major vector. Interactions between the mosquito host and dengue viruses (DENV are complex and vector competence varies among geographically-distinct Ae. aegypti populations. Additionally, dengue is caused by four antigenically-distinct viral serotypes (DENV1-4, each with multiple genotypes. Each virus genotype interacts differently with vertebrate and invertebrate hosts. Analyses of alterations in mosquito transcriptional profiles during DENV infection are expected to provide the basis for identifying networks of genes involved in responses to viruses and contribute to the molecular-genetic understanding of vector competence. In addition, this knowledge is anticipated to support the development of novel disease-control strategies. RNA-seq technology was used to assess genome-wide changes in transcript abundance at 1, 4 and 14 days following DENV2 infection in carcasses, midguts and salivary glands of the Ae. aegypti Chetumal strain. DENV2 affected the expression of 397 Ae. aegypti genes, most of which were down-regulated by viral infection. Differential accumulation of transcripts was mainly tissue- and time-specific. Comparisons of our data with other published reports reveal conservation of functional classes, but limited concordance of specific mosquito genes responsive to DENV2 infection. These results indicate the necessity of additional studies of mosquito-DENV interactions, specifically those focused on recently-derived mosquito strains with multiple dengue virus serotypes and genotypes.

  11. Parasitic nematodes modulate PIN-mediated auxin transport to facilitate infection.

    Directory of Open Access Journals (Sweden)

    Wim Grunewald

    2009-01-01

    Full Text Available Plant-parasitic nematodes are destructive plant pathogens that cause significant yield losses. They induce highly specialized feeding sites (NFS in infected plant roots from which they withdraw nutrients. In order to establish these NFS, it is thought that the nematodes manipulate the molecular and physiological pathways of their hosts. Evidence is accumulating that the plant signalling molecule auxin is involved in the initiation and development of the feeding sites of sedentary plant-parasitic nematodes. Intercellular transport of auxin is essential for various aspects of plant growth and development. Here, we analysed the spatial and temporal expression of PIN auxin transporters during the early events of NFS establishment using promoter-GUS/GFP fusion lines. Additionally, single and double pin mutants were used in infection studies to analyse the role of the different PIN proteins during cyst nematode infection. Based on our results, we postulate a model in which PIN1-mediated auxin transport is needed to deliver auxin to the initial syncytial cell, whereas PIN3 and PIN4 distribute the accumulated auxin laterally and are involved in the radial expansion of the NFS. Our data demonstrate that cyst nematodes are able to hijack the auxin distribution network in order to facilitate the infection process.

  12. Parasitic nematodes modulate PIN-mediated auxin transport to facilitate infection.

    Science.gov (United States)

    Grunewald, Wim; Cannoot, Bernard; Friml, Jirí; Gheysen, Godelieve

    2009-01-01

    Plant-parasitic nematodes are destructive plant pathogens that cause significant yield losses. They induce highly specialized feeding sites (NFS) in infected plant roots from which they withdraw nutrients. In order to establish these NFS, it is thought that the nematodes manipulate the molecular and physiological pathways of their hosts. Evidence is accumulating that the plant signalling molecule auxin is involved in the initiation and development of the feeding sites of sedentary plant-parasitic nematodes. Intercellular transport of auxin is essential for various aspects of plant growth and development. Here, we analysed the spatial and temporal expression of PIN auxin transporters during the early events of NFS establishment using promoter-GUS/GFP fusion lines. Additionally, single and double pin mutants were used in infection studies to analyse the role of the different PIN proteins during cyst nematode infection. Based on our results, we postulate a model in which PIN1-mediated auxin transport is needed to deliver auxin to the initial syncytial cell, whereas PIN3 and PIN4 distribute the accumulated auxin laterally and are involved in the radial expansion of the NFS. Our data demonstrate that cyst nematodes are able to hijack the auxin distribution network in order to facilitate the infection process.

  13. Nutritional modulation of age-related changes in the immune system and risk of infection

    Science.gov (United States)

    The immune system undergoes some adverse alterations during aging, many of which have been implicated in the increased morbidity and mortality associated with infection in the elderly. In addition to intrinsic changes to the immune system with aging, the elderly are more likely to have poor nutritio...

  14. Nutritional modulation of age-related changes in the immune system and risk of infection.

    Science.gov (United States)

    Pae, Munkyong; Wu, Dayong

    2017-05-01

    The immune system undergoes some adverse alterations during aging, many of which have been implicated in the increased morbidity and mortality associated with infection in the elderly. In addition to intrinsic changes to the immune system with aging, the elderly are more likely to have poor nutritional status, which further impacts the already impaired immune function. Although the elderly often have low zinc serum levels, several manifestations commonly observed during zinc deficiency are similar to the changes in immune function with aging. In the case of vitamin E, although its deficiency is rare, the intake above recommended levels is shown to enhance immune functions in the elderly and to reduce the risk of acquiring upper respiratory infections in nursing home residents. Vitamin D is a critical vitamin in bone metabolism, and its deficiency is far more common, which has been linked to increased risk of infection as demonstrated in a number of observational studies including those in the elderly. In this review, we focus on zinc, vitamin E, and vitamin D, the 3 nutrients which are relatively well documented for their roles in impacting immune function and infection in the elderly, to discuss the findings in this context reported in both the observational studies and interventional clinical trials. A perspective will be provided based on the analysis of information under review. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. B-1 cells modulate the murine macrophage response to Leishmania major infection.

    Science.gov (United States)

    Arcanjo, Angelica F; Nunes, Marise P; Silva-Junior, Elias B; Leandro, Monique; da Rocha, Juliana Dutra Barbosa; Morrot, Alexandre; Decote-Ricardo, Debora; Freire-de-Lima, Celio Geraldo

    2017-05-26

    To investigate the modulatory effect of B-1 cells on murine peritoneal macrophages infected with Leishmania major ( L. major ) in vitro . Peritoneal macrophages obtained from BALB/c and BALB/c XID mice were infected with L. major and cultured in the presence or absence of B-1 cells obtained from wild-type BALB/c mice. Intracellular amastigotes were counted, and interleukin-10 (IL-10) production was quantified in the cellular supernatants using an enzyme-linked immunosorbent assay. The levels of the lipid mediator prostaglandin E2 (PGE 2 ) were determined using a PGE 2 enzyme immunoassay kit (Cayman Chemical, Ann Arbor, MI), and the number of lipid bodies was quantified in the cytoplasm of infected macrophages in the presence and absence of B-1 cells. Culturing the cells with selective PGE 2 -neutralizing drugs inhibited PGE 2 production and confirmed the role of this lipid mediator in IL-10 production. In contrast, we demonstrated that B-1 cells derived from IL-10 KO mice did not favor the intracellular growth of L. major . We report that B-1 cells promote the growth of L. major amastigotes inside peritoneal murine macrophages. We demonstrated that the modulatory effect was independent of physical contact between the cells, suggesting that soluble factor(s) were released into the cultures. We demonstrated in our co-culture system that B-1 cells trigger IL-10 production by L. major -infected macrophages. Furthermore, the increased secretion of IL-10 was attributed to the presence of the lipid mediator PGE 2 in supernatants of L. major -infected macrophages. The presence of B-1 cells also favors the production of lipid bodies by infected macrophages. In contrast, we failed to obtain the same effect on parasite replication inside L. major -infected macrophages when the B-1 cells were isolated from IL-10 knockout mice. Our results show that elevated levels of PGE 2 and IL-10 produced by B-1 cells increase L. major growth, as indicated by the number of parasites in cell

  16. Determination of the Antimicrobial Effects of Hydro-Alcoholic Extract of Cannabis Sativa on Multiple Drug Resistant Bacteria Isolated from Nosocomial Infections

    Directory of Open Access Journals (Sweden)

    Hossein Sarmadyan

    2014-02-01

    Full Text Available Background: The science of identification and employment of medicinal plants dates back to the early days of man on earth. Cannabis (hashish is the most common illegal substance used in the United States and was subjected to extensive research as a powerful local disinfecting agent for mouth cavity and skin and an anti-tubercular agent in 1950. Methods: Clinical strains were isolated from hospitalized patients in Vali-e-Asr Hospital of Arak. The hydro-alcoholic extract of cannabis (5 g was prepared following liquid-liquid method and drying in 45˚C. The antimicrobial properties of the extract were determined through disk diffusion and determination of MIC (Minimum Inhibitory Concentration. Results: First, the sensitivity of bacteria was detected based on disk diffusion method and the zone of inhibition was obtained for MRSA (12 mm, S.aureus 25923 (14 mm, E. coli ESBL+: (10 mm, and Klebsiella pneumoniae (7 mm. Disk diffusion for Pseudomonas and Acinetobacter demonstrated no inhibitory zones. Through Broth dilution method, MIC of cannabis extract on the bacteria was determined: E.coli 25922: 50µg/ml, E.coli ESBL+:100 µg/ml, S.aureus 25923:25 µg/ml, MRSA: 50 µg/ml, Pseudomona aeroginosaESBL+> 100 µg/ml, Pseudomonas: 100 µg/ml, Klebsiella pneumoniae: 100 µg/ml, and Acinetobacter baumannii> 1000. Conclusion: The maximum anti-microbial effect of the hydro-alcoholic extract of cannabis was seen for gram positive cocci, especially S. aureus, whereas non-fermentative gram negatives presented resistance to the extract. This extract had intermediate effect on Enterobacteriacae family. Cannabis components extracted through chemical analysis can perhaps be effective in treatment of nosocomial infections.

  17. 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.

  18. SUN2 Modulates HIV-1 Infection and Latency through Association with Lamin A/C To Maintain the Repressive Chromatin.

    Science.gov (United States)

    Sun, Wei-Wei; Jiao, Shi; Sun, Li; Zhou, Zhaocai; Jin, Xia; Wang, Jian-Hua

    2018-05-01

    The postintegrational latency of HIV-1 is characterized by reversible silencing of long terminal repeat (LTR)-driven transcription of the HIV genome. It is known that the formation of repressive chromatin at the 5'-LTR of HIV-1 proviral DNA impedes viral transcription by blocking the recruitment of positive transcription factors. How the repressive chromatin is formed and modulated during HIV-1 infection remains elusive. Elucidation of which chromatin reassembly factor mediates the reorganization of chromatin is likely to facilitate the understanding of the host's modulation of HIV-1 transcription and latency. Here we revealed that "Sad1 and UNC84 domain containing 2" (SUN2), an inner nuclear membrane protein, maintained the repressive chromatin and inhibited HIV LTR-driven transcription of proviral DNA through an association with lamin A/C. Specifically, lamin A/C tethered SUN2 to the nucleosomes 1 and 2 of the HIV-1 5'-LTR to block the initiation and elongation of HIV-1 transcription. SUN2 knockdown converted chromatin to an active form and thus enhanced the phosphorylation of RNA polymerase II and its recruitment to the 5'-LTR HIV-1 proviral DNA, leading to reactivation of HIV-1 from latency. Conversely, the exogenous factors such as tumor necrosis factor alpha (TNF-α) induced reactivation, and the replication of HIV-1 led to the disassociation between SUN2 and lamin A/C, suggesting that disruption of the association between SUN2 and lamin A/C to convert the repressive chromatin to the active form might be a prerequisite for the initiation of HIV-1 transcription and replication. Together, our findings indicate that SUN2 is a novel chromatin reassembly factor that helps to maintain chromatin in a repressive state and consequently inhibits HIV-1 transcription. IMPORTANCE Despite the successful use of scores of antiretroviral drugs, HIV latency poses a major impediment to virus eradication. Elucidation of the mechanism of latency facilitates the discovery of new

  19. [FEMALE STEROID HORMONES - MODULATORS OF IMMUNE RESPONSE TO GENITAL CHLAMYDIA TRACHOMATIS INFECTION.

    Science.gov (United States)

    Kovachev, E; Ivanov, S; Bechev, B; Angelova, M; Grueva, E; Kolev, N; Ivanova, V

    In the recent years according to WHO, genital chlamydia is the mos't common sexually transmitted infection. Chlamydia Trachomatis is an intracellular parasite which target are the tubular epithelial cells of the urethra, endocervix, endometrium, endosalpinx, conjunctiva, synovial lining of the joints, Glisson's capsule of the liver Our study, as well as some international researches, shows that in the cases of genital chlamydia there are changes in the ovarian hormones (estradiol and progesterone), their impact on the immune system and their importance for the development and the complications of the infection with Chlamydia trachomatis. The physiological level of the steroid hormones in its turn contributes for the normalization of the local immunity and reduces the possibility of recurrences.

  20. Surfactant Protein D modulates HIV infection of both T-cells and dendritic cells.

    Directory of Open Access Journals (Sweden)

    Jens Madsen

    Full Text Available Surfactant Protein D (SP-D is an oligomerized C-type lectin molecule with immunomodulatory properties and involvement in lung surfactant homeostasis in the respiratory tract. SP-D binds to the enveloped viruses, influenza A virus and respiratory syncytial virus and inhibits their replication in vitro and in vivo. SP-D has been shown to bind to HIV via the HIV envelope protein gp120 and inhibit infectivity in vitro. Here we show that SP-D binds to different strains of HIV (BaL and IIIB and the binding occurs at both pH 7.4 and 5.0 resembling physiological relevant pH values found in the body and the female urogenital tract, respectively. The binding of SP-D to HIV particles and gp120 was inhibited by the presence of several hexoses with mannose found to be the strongest inhibitor. Competition studies showed that soluble CD4 and CVN did not interfere with the interaction between SP-D and gp120. However, soluble recombinant DC-SIGN was shown to inhibit the binding between SP-D and gp120. SP-D agglutinated HIV and gp120 in a calcium dependent manner. SP-D inhibited the infectivity of HIV strains at both pH values of 7.4 and 5.0 in a concentration dependent manner. The inhibition of the infectivity was abolished by the presence of mannose. SP-D enhanced the binding of HIV to immature monocyte derived dendritic cells (iMDDCs and was also found to enhance HIV capture and transfer to the T-cell like line PM1. These results suggest that SP-D can bind to and inhibit direct infection of T-cells by HIV but also enhance the transfer of infectious HIV particles from DCs to T-cells in vivo.

  1. Ketoconazole modulates the infectivity of Ichthyophonus sp. (Mesomycetozoa) in vivo in experimentally injected European sea bass.

    Science.gov (United States)

    Hontoria, Francisco; González, Ma Angeles; Sitjà-Bobadilla, Ariadna; Palenzuela, Oswaldo; Alvarez-Pellitero, Pilar

    2013-09-03

    In vitro studies have confirmed the inhibitory effect of the azol-derivative ketoconazole (KZ) on the growth of Ichthyophonus, an important pathogen causing epizootics in wild and cultured fish. We evaluated the effect of KZ in vivo in European sea bass Dicentrarchus labrax experimentally infected with the same Ichthyophonus isolate. Liposomes were used to vehiculate different doses of KZ to increase the effect on Ichthyophonus and lower the toxicity of the drug, and KZ toxicity was assessed in cultured sea bass juveniles. We also studied the effect of liposome-vehiculated KZ included in medicated food on ichthyophoniasis. KZ causes clear toxic effects in D. labrax juveniles at doses >80 mg kg-1, apparent in the reduced survival of fish and histological alterations to livers, kidneys and spleens. Fish injected with Ichthyophonus and treated with KZ dosages of ≤80 mg kg-1 d-1 presented lower ichthyophoniasis prevalence, fewer organs infected per fish, and fewer spores in the affected organs than the untreated fish. KZ seems to delay the onset of infection, but cannot stop further progression once established. However, this behaviour is not clearly reflected in the biometric and haematological data collected from these fish. We hypothesise that KZ's delaying effect would increase, if lower infective doses (more similar to natural situations) were used. The drug administration vehicle (liposomes vs. emulsions) did not affect the results. Our data confirm the potential utility of KZ in treating ichthyophoniasis and reveal its low toxicity for sea bass. Nevertheless, the optimal dose and appropriate application protocol remain to be determined.

  2. Ketoconazole modulates the infectivity of Ichthyophonus sp. (Mesomycetozoa) in vivo in experimentally injected European sea bass

    OpenAIRE

    Hontoria, Francisco; González, Mª Ángeles; Sitjà-Bobadilla, Ariadna; Palenzuela, Oswaldo

    2013-01-01

    In vitro studies have confirmed the inhibitory effect of the azol-derivative ketoconazole (KZ) on the growth of Ichthyophonus, an important pathogen causing epizootics in wild and cultured fish. We evaluated the effect of KZ in vivo in European sea bass Dicentrarchus labrax experimentally infected with the same Ichthyophonus isolate. Liposomes were used to vehiculate different doses of KZ to increase the effect on Ichthyophonus and lower the toxicity of the drug, and KZ toxicity was assessed ...

  3. Venezuelan equine encephalitis virus infection causes modulation of inflammatory and immune response genes in mouse brain

    Directory of Open Access Journals (Sweden)

    Puri Raj K

    2008-06-01

    Full Text Available Abstract Background Neurovirulent Venezuelan equine encephalitis virus (VEEV causes lethal encephalitis in equines and is transmitted to humans by mosquitoes. VEEV is highly infectious when transmitted by aerosol and has been developed as a bio-warfare agent, making it an important pathogen to study from a military and civilian standpoint. Molecular mechanisms of VEE pathogenesis are poorly understood. To study these, the gene expression profile of VEEV infected mouse brains was investigated. Changes in gene expression were correlated with histological changes in the brain. In addition, a molecular framework of changes in gene expression associated with progression of the disease was studied. Results Our results demonstrate that genes related to important immune pathways such as antigen presentation, inflammation, apoptosis and response to virus (Cxcl10, CxCl11, Ccl5, Ifr7, Ifi27 Oas1b, Fcerg1,Mif, Clusterin and MHC class II were upregulated as a result of virus infection. The number of over-expressed genes (>1.5-fold level increased as the disease progressed (from 197, 296, 400, to 1086 at 24, 48, 72 and 96 hours post infection, respectively. Conclusion Identification of differentially expressed genes in brain will help in the understanding of VEEV-induced pathogenesis and selection of biomarkers for diagnosis and targeted therapy of VEEV-induced neurodegeneration.

  4. A polyphenol-enriched diet and Ascaris suum infection modulate mucosal immune responses and gut microbiota composition in pigs

    DEFF Research Database (Denmark)

    Williams, Andrew R.; Krych, Lukasz; Ahmad, Hajar Fauzan

    2017-01-01

    . suum for 14 days to assess parasite establishment, acquisition of local and systemic immune responses and effects on the gut microbiome. Despite in vitro anthelmintic activity of GP-extracts, numbers of parasite larvae in the intestine were not altered by GP-supplementation. However, the bioactive diet......Polyphenols are a class of bioactive plant secondary metabolites that are thought to have beneficial effects on gut health, such as modulation of mucosal immune and inflammatory responses and regulation of parasite burdens. Here, we examined the interactions between a polyphenol-rich diet...... supplement and infection with the enteric nematode Ascaris suum in pigs. Pigs were fed either a basal diet or the same diet supplemented with grape pomace (GP), an industrial by-product rich in polyphenols such as oligomeric proanthocyanidins. Half of the animals in each group were then inoculated with A...

  5. 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.

  6. HIV-1 Infection of T Cells and Macrophages Are Differentially Modulated by Virion-Associated Hck: A Nef-Dependent Phenomenon

    Directory of Open Access Journals (Sweden)

    Gilda Tachedjian

    2013-09-01

    Full Text Available The proline repeat motif (PxxP of Nef is required for interaction with the SH3 domains of macrophage-specific Src kinase Hck. However, the implication of this interaction for viral replication and infectivity in macrophages and T lymphocytes remains unclear. Experiments in HIV-1 infected macrophages confirmed the presence of a Nef:Hck complex which was dependent on the Nef proline repeat motif. The proline repeat motif of Nef also enhanced both HIV-1 infection and replication in macrophages, and was required for incorporation of Hck into viral particles. Unexpectedly, wild-type Hck inhibited infection of macrophages, but Hck was shown to enhance infection of primary T lymphocytes. These results indicate that the interaction between Nef and Hck is important for Nef-dependent modulation of viral infectivity. Hck-dependent enhancement of HIV-1 infection of T cells suggests that Nef-Hck interaction may contribute to the spread of HIV-1 infection from macrophages to T cells by modulating events in the producer cell, virion and target cell.

  7. Plant growth-promoting endophytic bacteria versus pathogenic infections: an example of Bacillus amyloliquefaciens RWL-1 and Fusarium oxysporum f. sp. lycopersici in tomato

    Directory of Open Access Journals (Sweden)

    Raheem Shahzad

    2017-03-01

    Full Text Available Fungal pathogenic attacks are one of the major threats to the growth and productivity of crop plants. Currently, instead of synthetic fungicides, the use of plant growth-promoting bacterial endophytes has been considered intriguingly eco-friendly in nature. Here, we aimed to investigate the in vitro and in vivo antagonistic approach by using seed-borne endophytic Bacillus amyloliquefaciens RWL-1 against pathogenic Fusarium oxysporum f. sp. lycopersici. The results revealed significant suppression of pathogenic fungal growth by Bacillus amyloliquefaciens in vitro. Further to this, we inoculated tomato plants with RWL-1 and F. oxysporum f. sp. lycopersici in the root zone. The results showed that the growth attributes and biomass were significantly enhanced by endophytic-inoculation during disease incidence as compared to F. oxysporum f. sp. lycopersici infected plants. Under pathogenic infection, the RWL-1-applied plants showed increased amino acid metabolism of cell wall related (e.g., aspartic acid, glutamic acid, serine (Ser, and proline (Pro as compared to diseased plants. In case of endogenous phytohormones, significantly lower amount of jasmonic acid (JA and higher amount of salicylic acid (SA contents was recorded in RWL-1-treated diseased plants. The phytohormones regulation in disease incidences might be correlated with the ability of RWL-1 to produce organic acids (e.g., succinic acid, acetic acid, propionic acid, and citric acid during the inoculation and infection of tomato plants. The current findings suggest that RWL-1 inoculation promoted and rescued plant growth by modulating defense hormones and regulating amino acids. This suggests that bacterial endophytes could be used for possible control of F. oxysporum f. sp. lycopersici in an eco-friendly way.

  8. Unfolding Role of a Danger Molecule Adenosine Signaling in Modulation of Microbial Infection and Host Cell Response

    Directory of Open Access Journals (Sweden)

    Jaden S. Lee

    2018-01-01

    Full Text Available Ectonucleotidases CD39 and CD73, specific nucleotide metabolizing enzymes located on the surface of the host, can convert a pro-inflammatory environment driven by a danger molecule extracellular-ATP to an adenosine-mediated anti-inflammatory milieu. Accordingly, CD39/CD73 signaling has been strongly implicated in modulating the intensity, duration, and composition of purinergic danger signals delivered to host. Recent studies have eluted potential roles for CD39 and CD73 in selective triggering of a variety of host immune cells and molecules in the presence of pathogenic microorganisms or microbial virulence molecules. Growing evidence also suggests that CD39 and CD73 present complimentary, but likely differential, actions against pathogens to shape the course and severity of microbial infection as well as the associated immune response. Similarly, adenosine receptors A2A and A2B have been proposed to be major immunomodulators of adenosine signaling during chronic inflammatory conditions induced by opportunistic pathogens, such as oral colonizer Porphyromonas gingivalis. Therefore, we here review the recent studies that demonstrate how complex network of molecules in the extracellular adenosine signaling machinery and their interactions can reshape immune responses and may also be targeted by opportunistic pathogens to establish successful colonization in human mucosal tissues and modulate the host immune response.

  9. Edible bird's nest modulate intracellular molecular pathways of influenza A virus infected cells.

    Science.gov (United States)

    Haghani, Amin; Mehrbod, Parvaneh; Safi, Nikoo; Kadir, Fadzilah A'ini Abd; Omar, Abdul Rahman; Ideris, Aini

    2017-01-05

    Edible Bird's Nest (EBN) as a popular traditional Chinese medicine is believed to have health enhancing and antiviral activities against influenza A virus (IAV); however, the molecular mechanism behind therapeutic effects of EBN is not well characterized. In this study, EBNs that underwent different enzymatic preparation were tested against IAV infected cells. 50% cytotoxic concentration (CC 50 ) and 50% inhibitory concentration (IC 50 ) of the EBNs against IAV strain A/Puerto Rico/8/1934(H1N1) were determined by HA and MTT assays. Subsequently, the sialic acid content of the used EBNs were analyzed by fluorometric HPLC. Western Blotting and immunofluorescent staining were used to investigate the effects of EBNs on early endosomal trafficking and autophagy process of influenza virus. This study showed that post inoculations of EBNs after enzymatic preparations have the highest efficacy to inhibit IAV. While CC50 of the tested EBNs ranged from 27.5-32 mg/ml, the IC50 of these compounds ranged between 2.5-4.9 mg/ml. EBNs could inhibit IAV as efficient as commercial antiviral agents, such as amantadine and oseltamivir with different mechanisms of action against IAV. The antiviral activity of these EBNs correlated with the content of N-acetyl neuraminic acid. EBNs could affect early endosomal trafficking of the virus by reducing Rab5 and RhoA GTPase proteins and also reoriented actin cytoskeleton of IAV infected cells. In addition, for the first time this study showed that EBNs can inhibit intracellular autophagy process of IAV life cycle as evidenced by reduction of LC3-II and increasing of lysosomal degradation. The results procured in this study support the potential of EBNs as supplementary medication or alternative to antiviral agents to inhibit influenza infections. Evidently, EBNs can be a promising antiviral agent; however, these natural compounds should be screened for their metabolites prior to usage as therapeutic approach.

  10. Control of Vibrio harveyi Infection in Blue Swimming Crab, Portunus pelagicus Larvae by the Gut Isolated Lactic Acid Bacteria under Challenge Bioassay

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    Allah Dad Talpur*§, Abdul Jabbar Memon§, Muhammad Iqbal Khan§, Muhammad Ikhwanuddin, Muhammad Mhd Danish Daniel2 and Ambok Bolong Abol-Munafi

    2012-06-01

    Full Text Available Five isolates of lactic acid bacteria (LAB isolated from the gut of female Portunus pelagicus with inhibitory activity against shellfish pathogens and validation as probiotics via small scale in vivo model were tested for hatchery trials pathogen probiotic assay. Vibrio harveyi previously isolated from the gut of P. pelagicus, was added at 104 cfu mL-1 to test larvae for 10h. Test (LAB isolates were inoculated at a concentration of 106 cfu mL-1 to pathogen addition aquaria once and until day four during the experiment. 20 larvae/liter were stocked and larval survival was determined over five days. Lactobacillus plantarum did produce highest survival 28.33% to 48.33% in one day and daily inoculations respectively and in probiotic control it produced 58.33% survival followed by L. rhamnosus 55% and L. salivarius 53.33% respectively over non inoculated control 43.33% and 0% survival in V. harveyi inoculated control. However, Weissella confusa and W. cibaria did show less probiotic activity compared to rests of three LAB isolates. In the present study, it was determined that three LAB probiotics were effective in hatchery trials challenge assays which may significantly control the infection and increased the survival of larvae.

  11. Lipopolysaccharides in diazotrophic bacteria.

    Science.gov (United States)

    Serrato, Rodrigo V

    2014-01-01

    Biological nitrogen fixation (BNF) is a process in which the atmospheric nitrogen (N2) is transformed into ammonia (NH3) by a select group of nitrogen-fixing organisms, or diazotrophic bacteria. In order to furnish the biologically useful nitrogen to plants, these bacteria must be in constant molecular communication with their host plants. Some of these molecular plant-microbe interactions are very specific, resulting in a symbiotic relationship between the diazotroph and the host. Others are found between associative diazotrophs and plants, resulting in plant infection and colonization of internal tissues. Independent of the type of ecological interaction, glycans, and glycoconjugates produced by these bacteria play an important role in the molecular communication prior and during colonization. Even though exopolysaccharides (EPS) and lipochitooligosaccharides (LCO) produced by diazotrophic bacteria and released onto the environment have their importance in the microbe-plant interaction, it is the lipopolysaccharides (LPS), anchored on the external membrane of these bacteria, that mediates the direct contact of the diazotroph with the host cells. These molecules are extremely variable among the several species of nitrogen fixing-bacteria, and there are evidences of the mechanisms of infection being closely related to their structure.

  12. Bacteria modulate the CD8+ T cell epitope repertoire of host cytosol-exposed proteins to manipulate the host immune response.

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    Yaakov Maman

    2011-10-01

    Full Text Available The main adaptive immune response to bacteria is mediated by B cells and CD4+ T-cells. However, some bacterial proteins reach the cytosol of host cells and are exposed to the host CD8+ T-cells response. Both gram-negative and gram-positive bacteria can translocate proteins to the cytosol through type III and IV secretion and ESX-1 systems, respectively. The translocated proteins are often essential for the bacterium survival. Once injected, these proteins can be degraded and presented on MHC-I molecules to CD8+ T-cells. The CD8+ T-cells, in turn, can induce cell death and destroy the bacteria's habitat. In viruses, escape mutations arise to avoid this detection. The accumulation of escape mutations in bacteria has never been systematically studied. We show for the first time that such mutations are systematically present in most bacteria tested. We combine multiple bioinformatic algorithms to compute CD8+ T-cell epitope libraries of bacteria with secretion systems that translocate proteins to the host cytosol. In all bacteria tested, proteins not translocated to the cytosol show no escape mutations in their CD8+ T-cell epitopes. However, proteins translocated to the cytosol show clear escape mutations and have low epitope densities for most tested HLA alleles. The low epitope densities suggest that bacteria, like viruses, are evolutionarily selected to ensure their survival in the presence of CD8+ T-cells. In contrast with most other translocated proteins examined, Pseudomonas aeruginosa's ExoU, which ultimately induces host cell death, was found to have high epitope density. This finding suggests a novel mechanism for the manipulation of CD8+ T-cells by pathogens. The ExoU effector may have evolved to maintain high epitope density enabling it to efficiently induce CD8+ T-cell mediated cell death. These results were tested using multiple epitope prediction algorithms, and were found to be consistent for most proteins tested.

  13. MicroRNA-27b Modulates Inflammatory Response and Apoptosis during Mycobacterium tuberculosis Infection.

    Science.gov (United States)

    Liang, Shuxin; Song, Zhigang; Wu, Yongyan; Gao, Yuanpeng; Gao, Mingqing; Liu, Fayang; Wang, Fengyu; Zhang, Yong

    2018-04-16

    Mycobacterium tuberculosis poses a significant global health threat. MicroRNAs play an important role in regulating host anti-mycobacterial defense; however, their role in apoptosis-mediated mycobacterial elimination and inflammatory response remains unclear. In this study, we explored the role of microRNA-27b (miR-27b) in murine macrophage responses to M. tuberculosis infection. We uncovered that the TLR-2/MyD88/NF-κB signaling pathway induced the expression of miR-27b and miR-27b suppressed the production of proinflammatory factors and the activity of NF-κB, thereby avoiding an excessive inflammation during M. tuberculosis infection. Luciferase reporter assay and Western blotting showed that miR-27b directly targeted Bcl-2-associated athanogene 2 (Bag2) in macrophages. Overexpression of Bag2 reversed miR-27b-mediated inhibition of the production of proinflammatory factors. In addition, miR-27b increased p53-dependent cell apoptosis and the production of reactive oxygen species and decreased the bacterial burden. We also showed that Bag2 interacts with p53 and negatively regulates its activity, thereby controlling cell apoptosis and facilitating bacterial survival. In summary, we revealed a novel role of the miR-27b/Bag2 axis in the regulation of inflammatory response and apoptosis and provide a potential molecular host defense mechanism against mycobacteria. Copyright © 2018 by The American Association of Immunologists, Inc.

  14. Potassium-modulated physiological performance of mango plants infected by Ceratocystis fimbriata

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    Isaias Severino Cacique

    2017-08-01

    Full Text Available ABSTRACT Mango wilt, caused by the fungus Ceratocystis fimbriata, is an important disease affecting mango production. In view of the beneficial effects of potassium (K in other profitable crops and the lack of information about the effect of macronutrients on mango wilt development, the present study aimed to evaluate how mango plants supplied with K respond physiologically when infected by C. fimbriata. Mango plants (» 3 years old from cultivar Ubá were grown in plastic pots containing 58 mg of K·dm−3 (original K level based on the chemical analysis of the substrate or in plastic pots with substrate amended with a solution of 0.5 M potassium chloride (KCl to achieve the rate of 240 mg K·dm−3. Disease symptoms were more pronounced in inoculated plants grown at the lower K level. Substantial declines in stomatal conductance, in line with decreases in the internal-to-ambient CO2 concentration ratio and the absence of detectable changes in the chlorophyll a fluorescence parameters, suggest that the decrease in the net carbon assimilation rate is due, at least initially, to stomatal limitations. High concentrations of K and manganese were found in the stem tissues of inoculated plants and supplied with the highest K rate, most likely due to the involvement of these tissues in the local development of defense mechanisms. The results of this study suggest that the supply of K favored the physiological performance of mango plants and their resistance against C. fimbriata infection.

  15. Antimicrobial susceptibility profiles of gram-negative bacteria causing infections collected across India during 2014–2016: Study for monitoring antimicrobial resistance trend report

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    Balaji Veeraraghavan

    2018-01-01

    Full Text Available Background: The emergence of antibiotic resistance among bacterial pathogens in the hospital and community has increased the concern to the health-care providers due to the limited treatment options. Surveillance of antimicrobial resistance (AMR in frequently isolated bacterial pathogens causing severe infections is of great importance. The data generated will be useful for the clinicians to decide empiric therapy on the local epidemiological resistance profile of the antimicrobial agents. This study aims to monitor the distribution of bacterial pathogen and their susceptibility pattern to the commonly used antimicrobial agents. Materials and Methods: This study includes Gram-negative bacilli collected from intra-abdominal, urinary tract and respiratory tract infections during 2014–2016. Isolates were collected from seven hospitals across India. All the study isolates were characterised up to species level, and minimum inhibitory concentration was determined for a wide range of antimicrobials included in the study panel. The test results were interpreted as per standard Clinical Laboratory Standards Institute guidelines. Results: A total of 2731 isolates of gram-negative bacteria were tested during study period. The most frequently isolated pathogens were 44% of Escherichia coli (n = 1205 followed by 25% of Klebsiella pneumoniae (n = 676 and 11% of Pseudomonas aeruginosa (n = 308. Among the antimicrobials tested, carbapenems were the most active, followed by amikacin and piperacillin/tazobactam. The rate of extended-spectrum beta-lactamase (ESBL-positive isolates were ranged from 66%–77% in E. coli to 61%–72% in K. pneumoniae, respectively. Overall, colistin retains its activity in > 90% of the isolates tested and appear promising. Conclusion: Increasing rates of ESBL producers have been noted, which is alarming. Further, carbapenem resistance was also gradually increasing, which needs much attention. Overall, this study data show that

  16. Influence of vaginal bacteria and D- and L-lactic acid isomers on vaginal extracellular matrix metalloproteinase inducer: implications for protection against upper genital tract infections.

    Science.gov (United States)

    Witkin, Steven S; Mendes-Soares, Helena; Linhares, Iara M; Jayaram, Aswathi; Ledger, William J; Forney, Larry J

    2013-08-06

    We evaluated levels of vaginal extracellular matrix metalloproteinase inducer (EMMPRIN) and matrix metalloproteinase (MMP-8) in vaginal secretions in relation to the composition of vaginal bacterial communities and D- and L-lactic acid levels. The composition of vaginal bacterial communities in 46 women was determined by pyrosequencing the V1 to V3 region of 16S rRNA genes. Lactobacilli were dominant in 71.3% of the women, followed by Gardnerella (17.4%), Streptococcus (8.7%), and Enterococcus (2.2%). Of the lactobacillus-dominated communities, 51.5% were dominated by Lactobacillus crispatus, 36.4% by Lactobacillus iners, and 6.1% each by Lactobacillus gasseri and Lactobacillus jensenii. Concentrations of L-lactic acid were slightly higher in lactobacillus-dominated vaginal samples, but most differences were not statistically significant. D-Lactic acid levels were higher in samples containing L. crispatus than in those with L. iners (Pvaginal communities dominated by species of lactobacilli was in concordance with the proportions found in axenic cultures of the various species grown in vitro. Levels of L-lactic acid (Pvaginal concentrations of EMMPRIN and MMP-8 levels were highly correlated (Pinfections. A large proportion of preterm births (>50%) result from infections caused by bacteria originating in the vagina, which requires that they traverse the cervix. Factors that influence susceptibility to these infections are not well understood; however, there is evidence that matrix metalloproteinase (MMP-8) is known to alter the integrity of the cervix. In this work, we show that concentrations of vaginal extracellular matrix metalloproteinase inducer (EMMPRIN) are influenced by members of the vaginal microbial community and concentrations of D- or L-lactic acid isomers in vaginal secretions. Elevated levels of D-lactic acid and the ratio of D- to L-lactic acid influence EMMPRIN concentrations as well as MMP-8 levels. Thus, isomers of lactic acid may function as

  17. The alpha-tocopherol form of vitamin E reverses age-associated susceptibility to Streptococcus pneumoniae lung infection by modulating pulmonary neutrophil recruitment

    Science.gov (United States)

    Streptococcus pneumonia infections are an important cause of morbidity and mortality in older patients. Uncontrolled neutrophil-driven pulmonary inflammation exacerbates this disease. To test whether the alpha-tocopherol (alpha-Toc) form of vitamin E, a regulator of immunity, can modulate neutrophil...

  18. Stability evaluation of reference genes for real-time PCR in zebrafish (Danio rerio) exposed to cadmium chloride and subsequently infected by bacteria Aeromonas hydrophila

    Energy Technology Data Exchange (ETDEWEB)

    Lang, Xingping; Wang, Lan, E-mail: lanwang@sxu.edu.cn; Zhang, Zuobing, E-mail: zbzhang@sxu.edu.cn

    2016-01-15

    Highlights: • Cd exposure affects the stability of reference genes for real-time PCR in zebrafish. • Reference genes present different stability in the five tissues (spleen, kidney, liver, gills and intestine) of zebrafish after Cd exposure. • Bacterial infection further affects the stability of reference genes in Cd-treated zebrafish. - Abstract: Environmental and occupational cadmium (Cd) toxicity is a global concern, and the model organism zebrafish is an ideal species to investigate Cd toxicity. Among various detecting techniques, quantitative real-time PCR (qPCR) is a sensitive and efficient tool. Stable reference genes are critical for relative qPCR analysis. However, accumulated evidence shows that conventional reference genes can vary significantly under different experimental setups. Here we evaluated the stability of eight candidate reference genes of zebrafish with or without exposure to different concentrations of Cd. The results showed that the best four suitable reference genes in the five selected organs were: (1) spleen: β-actin > gapdh > ef1α > rpl13α; (2) kidney: rplp2 > rpl7 > β-actin > ef1α; (3) liver: rpl7 > rpl13α > β-actin > ef1α; (4) gills: rplp2 > gapdh > rnf7 > ef1α; (5) intestine: ef1α > rnf7 > rplp2 > rpl13α. Moreover, we further assessed the expression stability of the four reference genes for Cd immunotoxicology studies in zebrafish. The expression profiles showed that ef1α in spleen and kidney, rpl13a in liver and rplp2 in intestine were the most suitable reference genes at 12 h and 9 days after the injection with Aeromonas hydrophila following Cd exposure. In gills, the expression of gapdh was more stable than ef1α after 9 days of bacteria challenge while ef1α showed a higher stability than gapdh at 12 h after bacteria injection. In conclusion, this study has demonstrated that different tissues of zebrafish have different suitable reference genes after Cd exposure and the subsequently pathogenic insults for q

  19. Shigella Infections

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Shigella Infections KidsHealth / For Parents / Shigella Infections What's in ... Doctor Print en español Infecciones por Shigella About Shigella Shigella are bacteria that can infect the digestive ...

  20. Enriched cultures of lactic acid bacteria from selected Zimbabwean fermented food and medicinal products with potential as therapy or prophylaxis against yeast infections

    Directory of Open Access Journals (Sweden)

    Alec Chabwinja

    2017-10-01

    Full Text Available Objective: To investigate the antifungal activity of crude cultures of putative strains of lactic acid bacteria (LAB from a selection of Zimbabwean traditional and commercial food/ medicinal products against yeasts (strains of environmental isolates of Candida albicans and Rhodotorula spp.. Methods: Cultures of putative LAB from our selection of fermented products were enriched in de Man, Rogosa and Sharpe and isolated on de Man, Rogosa and Sharpe agar. Results: The crude microbial cultures from the products that showed high antifungal activities (zone of inhibition, mm were as follows: supernatant-free microbial pellet (SFMP from an extract of Melia azedarach leaves [(27.0 ± 2.5 mm] > cell-free culture supernatants (CFCS from Maaz Dairy sour milk and Mnandi sour milk [approximately (26.0 ± 1.8/2.5 mm] > CFCS and SFMP from Amansi hodzeko [(25.0 ± 1.5 mm] > CFCS from Parinari curatellifolia fruit [(24.0 ± 1.5 mm], SFMP from Parinari curatellifolia fruit [(24.0 ± 1.4 mm] and SFMP from mahewu [(20.0 ± 1.5 mm]. These cultures also showed high tolerance to acidic conditions (pH 4.0 and pH 5.0. However, culture from WAYA LGG (shown elsewhere to harbour antimicrobial activities showed no antifungal activity. The LAB could have inhibited yeasts by either competitive exclusion or the release of antimicrobial metabolites. Conclusions: Our cultures of LAB from a selection of Zimbabwean fermented products, especially Ziziphus mauritiana and fermented milk products have great potential for use as antifungal probiotics against yeast infections. Studies are ongoing to determine the exact mechanisms that are employed by the putative LAB to inhibit Candida albicans.

  1. Infection,

    Science.gov (United States)

    1980-10-16

    characteristic in severe gram-negative sepsis. Hypertriglyceridemia results from an increase in hepatic synthesis in combination with diminished activity of...induced stress, and tissue repair (1). The magnitude and type of nutritional losses caused by an infection reflect both the severity and duration of an... several functional forms of nutrient loss must be anticipated. Functional losses are defined as the within-body losses of nutrients due to infection

  2. Salivary Gland Extract Modulates the Infection of Two Leishmania enriettii Strains by Interfering With Macrophage Differentiation in the Model of Cavia porcellus

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    Lucélia J. Pinheiro

    2018-05-01

    Full Text Available The subgenus Mundinia includes several Leishmania species that have human and veterinary importance. One of those members, Leishmania Mundinia enriettii was isolated from the guinea pig Cavia porcellus in the 1940s. Several histopathological studies have already been performed in this species in the absence of salivary gland extract (SGE, which are determinant and the early and future events of the infection. Our main hypothesis is that SGE could differentially modulate the course of the lesion and macrophage differentiation caused by avirulent and virulent L. enriettii strains. Here, the C. porcellus nasal region was infected using needles with two strains of L. enriettii (L88 and Cobaia in the presence/absence of SGE and followed for 12 weeks. Those strains vary in terms of virulence, and their histopathological development was characterized. Some L88-infected animals could develop ulcerated/nodular lesions, whereas Cobaia strain developed non-ulcerated nodular lesions. Animals experimentally inoculated developed a protuberance and/or lesion after the 4th and 5th weeks of infection. Macroscopically, the size of lesion in L88-infected animals was smaller in the presence of SGE. Remarkable differences were detected microscopically in the presence of SGE for both strains. After the 6th and 7th weeks, L88-infected animals were heavily parasitized with an intense inflammatory profile bearing amastigotes and pro-inflammatory cells compared to those infected by Cobaia strain. Morphometry analysis revealed that L1+ macrophages were abundant in the L88 infection, but not in the Cobaia infection. In the presence of SGE, an increased CD163+ macrophage infiltrate by both strains was detected. Interestingly, this effect was more pronounced in Cobaia-infected animals. This study showed the role of SGE during the course of L. enriettii (strains L88 and Cobaia infection and its role in modulating macrophage attraction to the lesion site. SGE decreased L1

  3. Alternative sources of Legionella bacteria

    NARCIS (Netherlands)

    van Heijnsbergen, H.H.L.

    2017-01-01

    Legionella bacteria can cause Legionnaires’ disease (LD) in humans. Symptoms of LD can range from mild disease to severe pneumonia with sometimes fatal outcome. In the Netherlands, the most important infective agent is Legionella pneumophila. L. pneumophila infection is associated with aquatic

  4. Spinal Infections

    Science.gov (United States)

    ... the wound and re-closing to more extensive debridements and removal of infected tissues. In some cases ... will want to obtain cultures to determine the type of bacteria or fungus that is causing the ...

  5. The effect of Tea Misletoe (Scurrula oortiana Stem Extract as Immuno-Modulator on Oncogenic Marek’s Disease Virus Infection

    Directory of Open Access Journals (Sweden)

    Mulyoto Samsi

    2007-11-01

    Full Text Available Marek’s disease virus (MDV is one of oncogenic herpesvirus. It causes immunosupresion and cancer in chicken. Several plants produce bioactive compounds which are very useful for treatment of many disease, especially hiperproliveration and virus infection. This study was aimed to find out mechanism of immuno-modulatory capacity in layer commercial chicken administered orally with extract of tea parasite (Scurrula oortiana in dose of 10 mg/kg BW through drinking water, then the chicken were infected by intraperitoneal oncogenic MDV in dose of 1,0 x103 TCID50. The study used 60 layer commercial day old chicks (DOC divided into four group treatments. The treatments were group A (administered S. oortiana extract and without MDV infection, B (neither S. oortiana nor MDV infection, C (administered S. oortiana extract and with MDV infection, and D (without administered S. oortiana extract, but with MDV infection. Results showed that MDV oncogenic caused immunosupresion at a day post infection (p.i and recovery to be normal based on relative weight of bursa Fabricius and thymus at 40 days p.i. The extract of S. oortiana had a capability as an immunomodulator indicated by the increase of relative weight of bursa Fabricius and thymus at day 20 days p.i. (Animal Production 9(2: 172-177 (2007 Key Words: Marek’s disease virus (MDV, Scurrula oortiana, immuno-modulator

  6. Big bacteria

    DEFF Research Database (Denmark)

    Schulz, HN; Jørgensen, BB

    2001-01-01

    A small number of prokaryotic species have a unique physiology or ecology related to their development of unusually large size. The biomass of bacteria varies over more than 10 orders of magnitude, from the 0.2 mum wide nanobacteria to the largest cells of the colorless sulfur bacteria......, Thiomargarita namibiensis, with a diameter of 750 mum. All bacteria, including those that swim around in the environment, obtain their food molecules by molecular diffusion. Only the fastest and largest swimmers known, Thiovulum majus, are able to significantly increase their food supply by motility...... and by actively creating an advective flow through the entire population. Diffusion limitation generally restricts the maximal size of prokaryotic cells and provides a selective advantage for mum-sized cells at the normally low substrate concentrations in the environment. The largest heterotrophic bacteria...

  7. Big bacteria

    DEFF Research Database (Denmark)

    Schulz, HN; Jørgensen, BB

    2001-01-01

    A small number of prokaryotic species have a unique physiology or ecology related to their development of unusually large size. The biomass of bacteria varies over more than 10 orders of magnitude, from the 0.2 mum wide nanobacteria to the largest cells of the colorless sulfur bacteria...... and by actively creating an advective flow through the entire population. Diffusion limitation generally restricts the maximal size of prokaryotic cells and provides a selective advantage for mum-sized cells at the normally low substrate concentrations in the environment. The largest heterotrophic bacteria......, the 80 x 600 mum large Epulopiscium sp. from the gut of tropical fish, are presumably living in a very nutrient-rich medium. Many large bacteria contain numerous inclusions in the cells that reduce the volume of active cytoplasm. The most striking examples of competitive advantage from large cell size...

  8. Magnetic Bacteria.

    Science.gov (United States)

    Nelson, Jane Bray; Nelson, Jim

    1992-01-01

    Describes the history of Richard Blakemore's discovery of magnetotaxic organisms. Discusses possible reasons why the magnetic response in bacteria developed. Proposes research experiments integrating biology and physics in which students investigate problems using cultures of magnetotaxic organisms. (MDH)

  9. Bacteria, phages and septicemia.

    Directory of Open Access Journals (Sweden)

    Ausra Gaidelyte

    Full Text Available The use of phages is an attractive option to battle antibiotic resistant bacteria in certain bacterial infections, but the role of phage ecology in bacterial infections is obscure. Here we surveyed the phage ecology in septicemia, the most severe type of bacterial infection. We observed that the majority of the bacterial isolates from septicemia patients spontaneously secreted phages active against other isolates of the same bacterial strain, but not to the strain causing the disease. Such phages were also detected in the initial blood cultures, indicating that phages are circulating in the blood at the onset of sepsis. The fact that most of the septicemic bacterial isolates carry functional prophages suggests an active role of phages in bacterial infections. Apparently, prophages present in sepsis-causing bacterial clones play a role in clonal selection during bacterial invasion.

  10. TMV-Cg Coat Protein stabilizes DELLA proteins and in turn negatively modulates salicylic acid-mediated defense pathway during Arabidopsis thaliana viral infection.

    Science.gov (United States)

    Rodriguez, Maria Cecilia; Conti, Gabriela; Zavallo, Diego; Manacorda, Carlos Augusto; Asurmendi, Sebastian

    2014-08-03

    Plant viral infections disturb defense regulatory networks during tissue invasion. Emerging evidence demonstrates that a significant proportion of these alterations are mediated by hormone imbalances. Although the DELLA proteins have been reported to be central players in hormone cross-talk, their role in the modulation of hormone signaling during virus infections remains unknown. This work revealed that TMV-Cg coat protein (CgCP) suppresses the salicylic acid (SA) signaling pathway without altering defense hormone SA or jasmonic acid (JA) levels in Arabidopsis thaliana. Furthermore, it was observed that the expression of CgCP reduces plant growth and delays the timing of floral transition. Quantitative RT-qPCR analysis of DELLA target genes showed that CgCP alters relative expression of several target genes, indicating that the DELLA proteins mediate transcriptional changes produced by CgCP expression. Analyses by fluorescence confocal microscopy showed that CgCP stabilizes DELLA proteins accumulation in the presence of gibberellic acid (GA) and that the DELLA proteins are also stabilized during TMV-Cg virus infections. Moreover, DELLA proteins negatively modulated defense transcript profiles during TMV-Cg infection. As a result, TMV-Cg accumulation was significantly reduced in the quadruple-DELLA mutant Arabidopsis plants compared to wild type plants. Taken together, these results demonstrate that CgCP negatively regulates the salicylic acid-mediated defense pathway by stabilizing the DELLA proteins during Arabidopsis thaliana viral infection, suggesting that CgCP alters the stability of DELLAs as a mechanism of negative modulation of antiviral defense responses.

  11. The Verticillium-specific protein VdSCP7 localizes to the plant nucleus and modulates immunity to fungal infections.

    Science.gov (United States)

    Zhang, Lisha; Ni, Hao; Du, Xuan; Wang, Sheng; Ma, Xiao-Wei; Nürnberger, Thorsten; Guo, Hui-Shan; Hua, Chenlei

    2017-07-01

    Fungal pathogens secrete effector proteins to suppress plant basal defense for successful colonization. Resistant plants, however, can recognize effectors by cognate R proteins to induce effector-triggered immunity (ETI). By analyzing secretomes of the vascular fungal pathogen Verticillium dahliae, we identified a novel secreted protein VdSCP7 that targets the plant nucleus. The green fluorescent protein (GFP)-tagged VdSCP7 gene with either a mutated nuclear localization signal motif or with additional nuclear export signal was transiently expressed in Nicotiana benthamiana, and investigated for induction of plant immunity. The role of VdSCP7 in V. dahliae pathogenicity was characterized by gene knockout and complementation, and GFP labeling. Expression of the VdSCP7 gene in N. benthamiana activated both salicylic acid and jasmonate signaling, and altered the plant's susceptibility to the pathogens Botrytis cinerea and Phytophthora capsici. The immune response activated by VdSCP7 was highly dependent on its initial extracellular secretion and subsequent nuclear localization in plants. Knockout of the VdSCP7 gene significantly enhanced V. dahliae aggressiveness on cotton. GFP-labeled VdSCP7 is secreted by V. dahliae and accumulates in the plant nucleus. We conclude that VdSCP7 is a novel effector protein that targets the host nucleus to modulate plant immunity, and suggest that plants can recognize VdSCP7 to activate ETI during fungal infection. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  12. Purinergic signaling modulates the cerebral inflammatory response in experimentally infected fish with Streptococcus agalactiae: an attempt to improve the immune response.

    Science.gov (United States)

    Souza, Carine F; Baldissera, Matheus D; Bottari, Nathiele B; Moreira, Karen L S; da Rocha, Maria Izabel U M; da Veiga, Marcelo L; Santos, Roberto C V; Baldisserotto, Bernardo

    2018-06-01

    Appropriate control of the immune response is a critical determinant of fish health, and the purinergic cascade has an important role in the immune and inflammatory responses. This cascade regulates the levels of adenosine triphosphate (ATP), adenosine diphosphate, adenosine monophosphate and adenosine (Ado), molecules involved in physiological or pathological events as inflammatory and anti-inflammatory mediators. Thus, the aim of this study was to evaluate whether purinergic signaling, through the activities of nucleoside triphosphate diphosphohydrolase (NTPDase), 5'-nucleotidase, and adenosine deaminase (ADA), is capable of modulating the cerebral immune and inflammatory responses in silver catfish that is experimentally infected with Streptococcus agalactiae. Cerebral NTPDase (with ATP as substrate) and 5'-nucleotidase activities increased, while ADA activity decreased in silver catfish that is experimentally infected with S. agalactiae, compared to the control group. Moreover, the cerebral levels of ATP and Ado increased in infected animals compared to the uninfected control group. Brain histopathology in infected animals revealed inflammatory demyelination (the presence of occasional bubbly collections), increased cellular density in the area near to pia-mater and intercellular edema. Based on this evidence, the modulation of the purinergic cascade by the enzymes NTPDase, 5'-nucleotidase, and ADA exerts an anti-inflammatory profile due to the regulation of ATP and Ado levels. This suggests involvement of purinergic enzymes on streptococcosis pathogenesis, through regulating cerebral ATP and Ado levels, molecules known to participate in physiological or pathological events as inflammatory and anti-inflammatory mediators, respectively. In summary, the modulation of the cerebral purinergic cascade exerts an anti-inflammatory profile in an attempt to reduce inflammatory damage.

  13. Close Encounters of Lymphoid Cells and Bacteria

    Science.gov (United States)

    Cruz-Adalia, Aranzazu; Veiga, Esteban

    2016-01-01

    During infections, the first reaction of the host against microbial pathogens is carried out by innate immune cells, which recognize conserved structures on pathogens, called pathogen-associated molecular patterns. Afterward, some of these innate cells can phagocytose and destroy the pathogens, secreting cytokines that would modulate the immune response to the challenge. This rapid response is normally followed by the adaptive immunity, more specific and essential for a complete pathogen clearance in many cases. Some innate immune cells, usually named antigen-presenting cells, such as macrophages or dendritic cells, are able to process internalized invaders and present their antigens to lymphocytes, triggering the adaptive immune response. Nevertheless, the traditional boundary of separated roles between innate and adaptive immunity has been blurred by several studies, showing that very specialized populations of lymphocytes (cells of the adaptive immunity) behave similarly to cells of the innate immunity. These “innate-like” lymphocytes include γδ T cells, invariant NKT cells, B-1 cells, mucosal-associated invariant T cells, marginal zone B cells, and innate response activator cells, and together with the newly described innate lymphoid cells are able to rapidly respond to bacterial infections. Strikingly, our recent data suggest that conventional CD4+ T cells, the paradigm of cells of the adaptive immunity, also present innate-like behavior, capturing bacteria in a process called transinfection. Transinfected CD4+ T cells digest internalized bacteria like professional phagocytes and secrete large amounts of proinflammatory cytokines, protecting for further bacterial challenges. In the present review, we will focus on the data showing such innate-like behavior of lymphocytes following bacteria encounter. PMID:27774092

  14. Porphyromonas gingivalis as a Model Organism for Assessing Interaction of Anaerobic Bacteria with Host Cells.

    Science.gov (United States)

    Wunsch, Christopher M; Lewis, Janina P

    2015-12-17

    Anaerobic bacteria far outnumber aerobes in many human niches such as the gut, mouth, and vagina. Furthermore, anaerobic infections are common and frequently of indigenous origin. The ability of some anaerobic pathogens to invade human cells gives them adaptive measures to escape innate immunity as well as to modulate host cell behavior. However, ensuring that the anaerobic bacteria are live during experimental investigation of the events may pose challenges. Porphyromonas gingivalis, a Gram-negative anaerobe, is capable of invading a variety of eukaryotic non-phagocytic cells. This article outlines how to successfully culture and assess the ability of P. gingivalis to invade human umbilical vein endothelial cells (HUVECs). Two protocols were developed: one to measure bacteria that can successfully invade and survive within the host, and the other to visualize bacteria interacting with host cells. These techniques necessitate the use of an anaerobic chamber to supply P. gingivalis with an anaerobic environment for optimal growth. The first protocol is based on the antibiotic protection assay, which is largely used to study the invasion of host cells by bacteria. However, the antibiotic protection assay is limited; only intracellular bacteria that are culturable following antibiotic treatment and host cell lysis are measured. To assess all bacteria interacting with host cells, both live and dead, we developed a protocol that uses fluorescent microscopy to examine host-pathogen interaction. Bacteria are fluorescently labeled with 2',7'-Bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein acetoxymethyl ester (BCECF-AM) and used to infect eukaryotic cells under anaerobic conditions. Following fixing with paraformaldehyde and permeabilization with 0.2% Triton X-100, host cells are labeled with TRITC phalloidin and DAPI to label the cell cytoskeleton and nucleus, respectively. Multiple images taken at different focal points (Z-stack) are obtained for temporal

  15. Modulation of amniotic fluid activin-a and inhibin-a in women with preterm premature rupture of the membranes and infection-induced preterm birth.

    Science.gov (United States)

    Rosenberg, Victor A; Buhimschi, Irina A; Dulay, Antonette T; Abdel-Razeq, Sonya S; Oliver, Emily A; Duzyj, Christina M; Lipkind, Heather; Pettker, Christian M; Buhimschi, Catalin S

    2012-02-01

    Activins and inhibins are important modulators of inflammatory processes. We explored activation of amniotic fluid (AF) activin-A and inhibin-A system in women with intra-amniotic infection and preterm premature rupture of the membranes (PPROM). We analyzed 78 AF samples: '2nd trimester-control' (n=12), '3rd trimester-control' (n=14), preterm labor with intact membranes [positive-AF-cultures (n=13), negative-AF-cultures (n=13)], and PPROM [positive-AF-cultures (n=13), negative-AF-cultures (n=13)]. Activin-A levels were evaluated ex-vivo following incubation of amniochorion and placental villous explants with Gram-negative lipopolysaccharide (LPS) or Gram-positive (Pam3Cys) bacterial mimics. Ability of recombinant activin-A and inhibin-A to modulate inflammatory reactions in fetal membranes was explored through explants' IL-8 release. Activin-A and inhibin-A were present in human AF and were gestational age-regulated. Activin-A was significantly upregulated by infection. Lower inhibin-A levels were seen in PPROM. LPS elicited release of activin-A from amniochorion, but not from villous explants. Recombinant activin-A stimulated IL-8 release from amniochorion, an effect that was not reversed by inhibin-A. Human AF activin-A and inhibin-A are involved in biological processes linked to intra-amniotic infection/inflammation-induced preterm birth. © 2011 John Wiley & Sons A/S.

  16. Modulation of Dengue/Zika Virus Pathogenicity by Antibody-Dependent Enhancement and Strategies to Protect Against Enhancement in Zika Virus Infection

    Directory of Open Access Journals (Sweden)

    Rekha Khandia

    2018-04-01

    Full Text Available Antibody-dependent enhancement (ADE is a phenomenon in which preexisting poorly neutralizing antibodies leads to enhanced infection. It is a serious concern with mosquito-borne flaviviruses such as Dengue virus (DENV and Zika virus (ZIKV. In vitro experimental evidences have indicated the preventive, as well as a pathogenicity-enhancing role, of preexisting DENV antibodies in ZIKV infections. ADE has been confirmed in DENV but not ZIKV infections. Principally, the Fc region of the anti-DENV antibody binds with the fragment crystallizable gamma receptor (FcγR, and subsequent C1q interactions and immune effector functions are responsible for the ADE. In contrast to normal DENV infections, with ADE in DENV infections, inhibition of STAT1 phosphorylation and a reduction in IRF-1 gene expression, NOS2 levels, and RIG-1 and MDA-5 expression levels occurs. FcγRIIA is the most permissive FcγR for DENV-ADE, and under hypoxic conditions, hypoxia-inducible factor-1 alpha transcriptionally enhances expression levels of FcγRIIA, which further enhances ADE. To produce therapeutic antibodies with broad reactivity to different DENV serotypes, as well as to ZIKV, bispecific antibodies, Fc region mutants, modified Fc regions, and anti-idiotypic antibodies may be engineered. An in-depth understanding of the immunological and molecular mechanisms of DENV-ADE of ZIKV pathogenicity will be useful for the design of common and safe therapeutics and prophylactics against both viral pathogens. The present review discusses the role of DENV antibodies in modulating DENV/ZIKV pathogenicity/infection and strategies to counter ADE to protect against Zika infection.

  17. N-Terminomics TAILS Identifies Host Cell Substrates of Poliovirus and Coxsackievirus B3 3C Proteinases That Modulate Virus Infection

    Science.gov (United States)

    Jagdeo, Julienne M.; Dufour, Antoine; Klein, Theo; Solis, Nestor; Kleifeld, Oded; Kizhakkedathu, Jayachandran; Luo, Honglin; Overall, Christopher M.

    2018-01-01

    ABSTRACT Enteroviruses encode proteinases that are essential for processing of the translated viral polyprotein. In addition, viral proteinases also target host proteins to manipulate cellular processes and evade innate antiviral responses to promote replication and infection. Although some host protein substrates of enterovirus proteinases have been identified, the full repertoire of targets remains unknown. We used a novel quantitative in vitro proteomics-based approach, termed terminal amine isotopic labeling of substrates (TAILS), to identify with high confidence 72 and 34 new host protein targets of poliovirus and coxsackievirus B3 (CVB3) 3C proteinases (3Cpros) in HeLa cell and cardiomyocyte HL-1 cell lysates, respectively. We validated a subset of candidate substrates that are targets of poliovirus 3Cpro in vitro including three common protein targets, phosphoribosylformylglycinamidine synthetase (PFAS), hnRNP K, and hnRNP M, of both proteinases. 3Cpro-targeted substrates were also cleaved in virus-infected cells but not noncleavable mutant proteins designed from the TAILS-identified cleavage sites. Knockdown of TAILS-identified target proteins modulated infection both negatively and positively, suggesting that cleavage by 3Cpro promotes infection. Indeed, expression of a cleavage-resistant mutant form of the endoplasmic reticulum (ER)-Golgi vesicle-tethering protein p115 decreased viral replication and yield. As the first comprehensive study to identify and validate functional enterovirus 3Cpro substrates in vivo, we conclude that N-terminomics by TAILS is an effective strategy to identify host targets of viral proteinases in a nonbiased manner. IMPORTANCE Enteroviruses are positive-strand RNA viruses that encode proteases that cleave the viral polyprotein into the individual mature viral proteins. In addition, viral proteases target host proteins in order to modulate cellular pathways and block antiviral responses in order to facilitate virus infection

  18. The colonization resistance of the digestive tract in experimental animals and its consequences for infection prevention, acquisition of new bacteria and the prevention of spread of bacteria in cage mates

    International Nuclear Information System (INIS)

    Waaij, D. van der

    1979-01-01

    Relevant animal experiments, some of them with sublethally and lethally irradiated animals, have been surveyed. The studies strongly suggest that more attention should be paid to the properties of antibiotics regarding the resistance to colonization. In selecting antibiotics for the treatment of an infection, the activity which antimicrobial drugs may have on the CR in addition to the standard criteria, should be taken into consideration. (Auth./C.F.)

  19. Bacteria-surface interactions.

    Science.gov (United States)

    Tuson, Hannah H; Weibel, Douglas B

    2013-05-14

    The interaction of bacteria with surfaces has important implications in a range of areas, including bioenergy, biofouling, biofilm formation, and the infection of plants and animals. Many of the interactions of bacteria with surfaces produce changes in the expression of genes that influence cell morphology and behavior, including genes essential for motility and surface attachment. Despite the attention that these phenotypes have garnered, the bacterial systems used for sensing and responding to surfaces are still not well understood. An understanding of these mechanisms will guide the development of new classes of materials that inhibit and promote cell growth, and complement studies of the physiology of bacteria in contact with surfaces. Recent studies from a range of fields in science and engineering are poised to guide future investigations in this area. This review summarizes recent studies on bacteria-surface interactions, discusses mechanisms of surface sensing and consequences of cell attachment, provides an overview of surfaces that have been used in bacterial studies, and highlights unanswered questions in this field.

  20. Concomitant ingestion of lactic acid bacteria and black tea synergistically enhances flavonoid bioavailability and attenuates d-galactose-induced oxidative stress in mice via modulating glutathione antioxidant system.

    Science.gov (United States)

    Zhao, Danyue; Shah, Nagendra P

    2016-12-01

    Black tea (BT) has been positively linked to improved redox status, while its efficacy is limited due to the low bioavailability of BT flavonoids. In addition to the direct antioxidant activity, flavonoids regulate redox balance via inducing endogenous antioxidants, particularly glutathione (GSH) and GSH-dependent antioxidant enzymes. This work first examined the effect of lactic acid bacteria (LAB) and BT alone or in combination on flavonoid bioavailability and metabolism; next, the effect of LAB-fermented BT diet in attenuating oxidative stress in mice and the underlying mechanisms were studied. Phenolic profiles of plasma, urine and feces from healthy mice consuming plain yogurt, BT milk (BTM) or BT yogurt (BTY) were acquired using LC-MS/MS. Plasma antioxidant capacity, lipid peroxidation level, content of nonprotein thiols and expression of GSH-related antioxidant enzymes and Nrf2 were examined in d-galactose-treated mice. Total flavonoid content in plasma following a single dose of BTY attained 0.657 μmol/l, increased by 50% compared with the BTM group. Increased excretion of phenolic metabolite and hippuric acid in urine and feces indicated enhanced metabolism of flavonoids in BTY-fed mice. In the second study, 8-week concomitant LAB-BT treatment of oxidatively stressed mice effectively restored plasma antioxidant capacity and GSH levels, and mitigated lipid peroxidation, which were associated with significant induction of GSH-dependent antioxidant enzymes and nuclear accumulation of Nrf2. Our results demonstrated the effect of LAB fermentation in enhancing BT flavonoid bioavailability in vivo. The synergistic antioxidant efficacy of LAB-BT diet implied its therapeutic potential in enhancing antioxidant defenses and protecting organisms from oxidative damage. Copyright © 2016. Published by Elsevier Inc.

  1. [Bacteriophages in the battle against multidrug resistant bacteria

    NARCIS (Netherlands)

    Meer, J.W.M. van der; Vandenbroucke-Grauls, C.

    2018-01-01

    Bacteriophages are viruses that infect bacteria. They are highly specific for a bacterial species. The so-called 'lytic phages' can lyse bacteria when they infect them; these phages can be used to treat bacterial infections. Despite a century of experience with phage therapy, the evidence for

  2. Viral and bacterial septicaemic infections modulate the expression of PACAP splicing variants and VIP/PACAP receptors in brown trout immune organs.

    Science.gov (United States)

    Gorgoglione, Bartolomeo; Carpio, Yamila; Secombes, Christopher J; Taylor, Nick G H; Lugo, Juana María; Estrada, Mario Pablo

    2015-12-01

    Pituitary Adenylate Cyclase-Activating Polypeptide (PACAP) and PACAP-Related Peptide (PRP) are structurally similar peptides encoded in the same transcripts. Their transcription has been detected not only in the brain but also in a wide range of peripheral tissues, even including organs of the immune system. PACAP exerts pleiotropic activities through G-protein coupled membrane receptors: the PACAP-specific PAC-1 and the VPAC-1 and VPAC-2 receptors that exhibit similar affinities for the Vasoactive Intestinal Peptide (VIP) and PACAP. Recent findings added PACAP and its receptors to the growing list of mediators that allow cross-talk between the nervous, endocrine and immune systems in fish. In this study the expression of genes encoding for PACAP and PRP, as well as VIP/PACAP receptors was studied in laboratory-reared brown trout (Salmo trutta) after septicaemic infections. Respectively Viral Haemorrhagic Septicaemia Virus (VHSV-Ia) or the Gram-negative bacterium Yersinia ruckeri (ser. O1 - biot. 2) were used in infection challenges. Kidney and spleen, the teleost main lymphopoietic organs, were sampled during the first two weeks post-infection. RT-qPCR analysis assessed specific pathogens burden and gene expression levels. PACAP and PRP transcription in each organ was positively correlated to the respective pathogen burden, assessed targeting the VHSV-glycoprotein or Y. ruckeri 16S rRNA. Results showed as the transcription of PACAP splicing variants and VIP/PACAP receptors is modulated in these organs during an acute viral and bacterial septicaemic infections in brown trout. These gene expression results provide clues as to how the PACAP system is modulated in fish, confirming an involvement during active immune responses elicited by both viral and bacterial aetiological agents. However, further experimental evidence is still required to fully elucidate and characterize the role of PACAP and PRP for an efficient immune response against pathogens. Copyright © 2015

  3. Herpes simplex virus 2 modulates apoptosis and stimulates NF-κB nuclear translocation during infection in human epithelial HEp-2 cells

    International Nuclear Information System (INIS)

    Yedowitz, Jamie C.; Blaho, John A.

    2005-01-01

    Virus-mediated apoptosis is well documented in various systems, including herpes simplex virus 1 (HSV-1). HSV-2 is closely related to HSV-1 but its apoptotic potential during infection has not been extensively scrutinized. We report that (i) HEp-2 cells infected with HSV-2(G) triggered apoptosis, assessed by apoptotic cellular morphologies, oligosomal DNA laddering, chromatin condensation, and death factor processing when a translational inhibitor (CHX) was added at 3 hpi. Thus, HSV-2 induced apoptosis but was unable to prevent the process from killing cells. (ii) Results from a time course of CHX addition experiment indicated that infected cell protein produced between 3 and 5 hpi, termed the apoptosis prevention window, are required for blocking virus-induced apoptosis. This corresponds to the same prevention time frame as reported for HSV-1. (iii) Importantly, CHX addition prior to 3 hpi led to less apoptosis than that at 3 hpi. This suggests that proteins produced immediately upon infection are needed for efficient apoptosis induction by HSV-2. This finding is different from that observed previously with HSV-1. (iv) Infected cell factors produced during the HSV-2(G) prevention window inhibited apoptosis induced by external TNFα plus cycloheximide treatment. (v) NF-κB translocated to nuclei and its presence in nuclei correlated with apoptosis prevention during HSV-2(G) infection. (vi) Finally, clinical HSV-2 isolates induced and prevented apoptosis in HEp-2 cells in a manner similar to that of laboratory strains. Thus, while laboratory and clinical HSV-2 strains are capable of modulating apoptosis in human HEp-2 cells, the mechanism of HSV-2 induction of apoptosis differs from that of HSV-1

  4. ChpK and MazF of the toxin-antitoxin modules are involved in the virulence of Leptospira interrogans during infection.

    Science.gov (United States)

    Komi, Komi Koukoura; Ge, Yu-Mei; Xin, Xiao-Yang; Ojcius, David M; Sun, Dexter; Hu, Wei-Lin; Zhao, Xin; Lin, Xu'ai; Yan, Jie

    2015-01-01

    Pathogenic Leptospira species are the causative agents of leptospirosis, a global zoonotic infectious disease. Toxin-antitoxin (TA) modules have been confirmed as stress-response elements that induce prokaryotic and eukaryotic cell-growth arrest or death, but their role in the virulence of Leptospira has not been reported. Here, we confirmed that all the tested leptospiral strains had the chpIK and mazEF TA modules with highly-conserved sequences. The transcription and expression of the chpI, chpK, mazE, and mazF genes of Leptospira interrogans strain Lai were significantly increased during infection of phorbol 12-myristate 13-acetate-induced human THP-1 macrophages. The toxic ChpK and MazF but not the antitoxic ChpI and MazE proteins were detectable in the cytoplasmic fraction of leptospire-infected THP-1 cells, indicating the external secretion of ChpK and MazF during infection. Transfection of the chpK or mazF gene caused decreased viability and necrosis in THP-1 cells, whereas the chpI or mazE gene transfection did not affect the viability of THP-1 cells but blocked the ChpK or MazF-induced toxicity. Deletion of the chpK or mazF gene also decreased the late-apoptotic and/or necrotic ratios of THP-1 cells at the late stages of infection. The recombinant protein MazF (rMazF) cleaved the RNAs but not the DNAs from Leptospira and THP-1 cells, and this RNA cleavage was blocked by rMazE. However, the rChpK had no RNA or DNA-degrading activity. All these findings indicate that the ChpK and MazF proteins in TA modules are involved in the virulence of L. interrogans during infection. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  5. Evidence that Vpu modulates HIV-1 Gag-envelope interaction towards envelope incorporation and infectivity in a cell type dependent manner.

    Directory of Open Access Journals (Sweden)

    Archana Gautam

    Full Text Available The HIV-1 Vpu is required for efficient virus particle release from the plasma membrane and intracellular CD4 degradation in infected cells. In the present study, we found that the loss of virus infectivity as a result of envelope (Env incorporation defect caused by a Gag matrix (MA mutation (L30E was significantly alleviated by introducing a start codon mutation in vpu. Inactivation of Vpu partially restored the Env incorporation defect imposed by L30E substitution in MA. This effect was found to be comparable in cell types such as 293T, HeLa, NP2 and GHOST as well as in peripheral blood mononuclear cells (PBMC and monocyte-derived macrophages (MDM. However, in HeLa cells BST-2 knockdown was found to further alleviate the effect of Vpu inactivation on infectivity of L30E mutant. Our data demonstrated that the impaired infectivity of virus particles due to Env incorporation defect caused by MA mutation was modulated by start codon mutation in Vpu.

  6. Human Leukocyte Antigen (HLA and Immune Regulation: How Do Classical and Non-Classical HLA Alleles Modulate Immune Response to Human Immunodeficiency Virus and Hepatitis C Virus Infections?

    Directory of Open Access Journals (Sweden)

    Nicole B. Crux

    2017-07-01

    Full Text Available The genetic factors associated with susceptibility or resistance to viral infections are likely to involve a sophisticated array of immune response. These genetic elements may modulate other biological factors that account for significant influence on the gene expression and/or protein function in the host. Among them, the role of the major histocompatibility complex in viral pathogenesis in particular human immunodeficiency virus (HIV and hepatitis C virus (HCV, is very well documented. We, recently, added a novel insight into the field by identifying the molecular mechanism associated with the protective role of human leukocyte antigen (HLA-B27/B57 CD8+ T cells in the context of HIV-1 infection and why these alleles act as a double-edged sword protecting against viral infections but predisposing the host to autoimmune diseases. The focus of this review will be reexamining the role of classical and non-classical HLA alleles, including class Ia (HLA-A, -B, -C, class Ib (HLA-E, -F, -G, -H, and class II (HLA-DR, -DQ, -DM, and -DP in immune regulation and viral pathogenesis (e.g., HIV and HCV. To our knowledge, this is the very first review of its kind to comprehensively analyze the role of these molecules in immune regulation associated with chronic viral infections.

  7. Correlation-based iterative clustering methods for time course data: The identification of temporal gene response modules for influenza infection in humans

    Directory of Open Access Journals (Sweden)

    Michelle Carey

    2016-10-01

    Full Text Available Many pragmatic clustering methods have been developed to group data vectors or objects into clusters so that the objects in one cluster are very similar and objects in different clusters are distinct based on some similarity measure. The availability of time course data has motivated researchers to develop methods, such as mixture and mixed-effects modelling approaches, that incorporate the temporal information contained in the shape of the trajectory of the data. However, there is still a need for the development of time-course clustering methods that can adequately deal with inhomogeneous clusters (some clusters are quite large and others are quite small. Here we propose two such methods, hierarchical clustering (IHC and iterative pairwise-correlation clustering (IPC. We evaluate and compare the proposed methods to the Markov Cluster Algorithm (MCL and the generalised mixed-effects model (GMM using simulation studies and an application to a time course gene expression data set from a study containing human subjects who were challenged by a live influenza virus. We identify four types of temporal gene response modules to influenza infection in humans, i.e., single-gene modules (SGM, small-size modules (SSM, medium-size modules (MSM and large-size modules (LSM. The LSM contain genes that perform various fundamental biological functions that are consistent across subjects. The SSM and SGM contain genes that perform either different or similar biological functions that have complex temporal responses to the virus and are unique to each subject. We show that the temporal response of the genes in the LSM have either simple patterns with a single peak or trough a consequence of the transient stimuli sustained or state-transitioning patterns pertaining to developmental cues and that these modules can differentiate the severity of disease outcomes. Additionally, the size of gene response modules follows a power-law distribution with a consistent

  8. Distribution and Antimicrobial Susceptibility Pattern of Gram Negative Bacteria Causing Urinary Tract Infection (UTI and Detection New Delhi Metallo-beta-lactamase-1 (NDM-1 Producing Isolates in Ahwaz

    Directory of Open Access Journals (Sweden)

    Parviz Afrugh

    2016-04-01

    Full Text Available Background: Urinary tract infection (UTI is the commonest bacterial infectious disease in worldwide (especially in developing countries with a high rate of morbidity and financial cost. The management of UTI infections has been jeopardized by increase in immergence of antimicrobial drug resistance. Knowledge of the local bacterial etiology and susceptibility patterns is required to trace any change that might have occurred in time so that updated recommendation for optimal empirical therapy of UTI can be made. The aim of this investigation was distribution and antimicrobial susceptibility pattern of gram negative bacteria causing urinary tract infection (UTI and detection NDM-1 (new-delhi-metallo-beta-lactamase-1 producing isolates in Ahwaz. Materials and Methods: This cross-sectional study was done during a period of one year from April 2013 to March 2014. Clean catch midstream urine samples were collected from suspected patients to UTI. The isolates were identified based on morphological and biochemical testes. Culture was performed on routine microbiological media. Susceptibility testing was performed according CLSI (2013 guidelines. Detection of carbapenemase producing isolates was performed by modified hodge test (MHT. Metallo-beta-lactamase isolates were detected by imipenem-EDTA combined disc test (CDT. Results: In this study 708 gram negative organisms were isolated from urine samples. E.coli was the most common isolated bacteria (67% followed by Klebsiella spp. (26.5% and Enterobacter spp. (2.5%. In antibiotic susceptibility testing more than 90% of isolates were sensitive to tetracycline, ceftazidime, meropenem, amikacin, cefotaxime, imipenem, and cefepime. Isolates were more resistant to cephalothin (32%, co-trimoxazol (30.5%, and nalidixic acid (25%. Conclusion: In our results isolated organisms from outpatients showed very high sensitivity to common antibiotics. Continuous and regular monitoring of susceptibility pattern of

  9. Appropriateness of antibiotic prescription for targeted therapy of infections caused by multidrug-resistant bacteria: assessment of the most common improper uses in a tertiary hospital in southern Italy.

    Science.gov (United States)

    Viceconte, Giulio; Maraolo, Alberto Enrico; Iula, Vita Dora; Catania, Maria Rosaria; Tosone, Grazia; Orlando, Raffaele

    2017-09-01

    A huge proportion of antibiotic therapies for infections caused by multidrug-resistant bacteria (MDR) are inappropriate. In this study, we described the most common causes of inappropriateness of definitive antibiotic regimes in a large university hospital in southern Italy and we evaluated the impact on microbial eradication, length of stay, 30-day readmission and mortality. We retrospectively assessed 45 patients who received a definitive antibiotic therapy after isolation of multidrug-resistant Staphylococcus aureus, Enterococcus spp., Enterobacteriaceae, Pseudomonas aeruginosa and Acinetobacter spp. strains between 2014 and 2015. From the literature, we set a series of criteria to retrospectively determine the appropriateness of the therapy. In all, 61% of the prescribed antibiotic regimes were found to be inappropriate, especially due to incorrect drug dosage. It emerged that meropenem was the antibiotic most frequently inappropriately used. In 46% of infections caused by MDR but not extended-spectrum β-lactamase-producing Enterobacteriaceae, carbapenems were inappropriately administered. Microbial eradication was achieved in 87% of the appropriate therapy group compared to 31% of the inappropriate therapy group (chi-square=6.750, p<0.027). No statistically significant association was found between inappropriate therapy and the length of stay (chi-square=3.084, p=0.101) and 30-day readmission (p=0.103). Definitive antibiotic therapy in infections caused by multidrug-resistant bacteria in a large university hospital is often inappropriate, especially due to the drug dosing regimen, particularly in the case of meropenem and colistin. This inappropriateness has a significant impact on post-treatment microbial eradication in specimens collected after antibiotic therapy.

  10. Reduced sTWEAK and increased sCD163 levels in HIV-infected patients: modulation by antiretroviral treatment, HIV replication and HCV co-infection.

    Directory of Open Access Journals (Sweden)

    Luis M Beltrán

    Full Text Available Patients infected with the human immunodeficiency virus (HIV have an increased risk of cardiovascular disease due to increased inflammation and persistent immune activation. CD163 is a macrophage scavenger receptor that is involved in monocyte-macrophage activation in HIV-infected patients. CD163 interacts with TWEAK, a member of the TNF superfamily. Circulating levels of sTWEAK and sCD163 have been previously associated with cardiovascular disease, but no previous studies have fully analyzed their association with HIV.The aim of this study was to analyze circulating levels of sTWEAK and sCD163 as well as other known markers of inflammation (hsCRP, IL-6 and sTNFRII and endothelial dysfunction (sVCAM-1 and ADMA in 26 patients with HIV before and after 48 weeks of antiretroviral treatment (ART and 23 healthy subjects.Patients with HIV had reduced sTWEAK levels and increased sCD163, sVCAM-1, ADMA, hsCRP, IL-6 and sTNFRII plasma concentrations, as well as increased sCD163/sTWEAK ratio, compared with healthy subjects. Antiretroviral treatment significantly reduced the concentrations of sCD163, sVCAM-1, hsCRP and sTNFRII, although they remained elevated when compared with healthy subjects. Antiretroviral treatment had no effect on the concentrations of ADMA and sTWEAK, biomarkers associated with endothelial function. The use of protease inhibitors as part of antiretroviral therapy and the presence of HCV-HIV co-infection and/or active HIV replication attenuated the ART-mediated decrease in sCD163 plasma concentrations.HIV-infected patients showed a proatherogenic profile characterized by increased inflammatory, immune-activation and endothelial-dysfunction biomarkers that partially improved after ART. HCV-HIV co-infection and/or active HIV replication enhanced immune activation despite ART.

  11. First insight into the heritable variation of the resistance to infection with the bacteria causing the withering syndrome disease in Haliotis rufescens abalone.

    Science.gov (United States)

    Brokordt, Katherina; González, Roxana; Farías, William; Winkler, Federico E; Lohrmann, Karin B

    2017-11-01

    Withering syndrome disease has experienced worldwide spread in the last decade. This fatal disease for abalone is produced by a rickettsia-like organism (WS-RLO), the bacterium "Candidatus Xenohaliotis californiensis". To evaluate the potential of the red abalone (Haliotis rufescens) to improve its resistance to infection by WS-RLO, the additive genetic component in the variation of this trait was estimated. For this, the variation in infection intensity with WS-RLOs and WS-RLOv (phage-infected RLOs) was analyzed in 56 families of full-sibs maintained for three years in a host-parasite cohabitation aquaculture system. A WS-RLO prevalence of 65% was observed in the analysed population; and from the total WS-RLO inclusions 60% were hyperparasited with the phage (WS-RLOv). The decrease in the food ingestion rate was the sole negative effect associated with increasing WS-RLO intensity of infection, suggesting that the high level of WS-RLOv load may have diminished the symptoms of WS disease in the analyzed abalones. The estimated heritabilities were moderate to mid, but significant, varying from 0.21 to 0.23 and 0.36 for WS-RLO and WS-RLOv infections, respectively. This suggests that variation in resistance to infection with WS-RLO may respond to selection in the evaluated red abalone population. Estimated response to selection (G) for the level of infection by WS-RLO indicated that if the 10% of red abalone with the lowest infection level is selected as broodstock, a 90% reduction in the intensity of infection in the progeny can be expected, even with the lowest estimation of heritability (h 2 =0.21). This strong response would be also due to the large phenotypic variance of this trait. Strong positive correlations, both phenotypic and genotypic, were observed between infection intensities with WS-RLO and WS-RLOv, indicating that selection to increase resistance to one of the types of RLOs will affect resistance in the other in the same direction. This is the first

  12. TLR2-Modulating Lipoproteins of the Mycobacterium tuberculosis Complex Enhance the HIV Infectivity of CD4+ T Cells.

    Science.gov (United States)

    Skerry, Ciaran; Klinkenberg, Lee G; Page, Kathleen R; Karakousis, Petros C

    2016-01-01

    Co-infection with Mycobacterium tuberculosis accelerates progression from HIV to AIDS. Our previous studies showed that M. tuberculosis complex, unlike M. smegmatis, enhances TLR2-dependent susceptibility of CD4+ T cells to HIV. The M. tuberculosis complex produces multiple TLR2-stimulating lipoproteins, which are absent in M. smegmatis. M. tuberculosis production of mature lipoproteins and TLR2 stimulation is dependent on cleavage by lipoprotein signal peptidase A (LspA). In order to determine the role of potential TLR2-stimulating lipoproteins on mycobacterial-mediated HIV infectivity of CD4+ T cells, we generated M. smegmatis recombinant strains overexpressing genes encoding various M. bovis BCG lipoproteins, as well as a Mycobacterium bovis BCG strain deficient in LspA (ΔlspA). Exposure of human peripheral blood mononuclear cells (PBMC) to M. smegmatis strains overexpressing the BCG lipoproteins, LprF (p<0.01), LprH (p<0.05), LprI (p<0.05), LprP (p<0.001), LprQ (p<0.005), MPT83 (p<0.005), or PhoS1 (p<0.05), resulted in increased HIV infectivity of CD4+ T cells isolated from these PBMC. Conversely, infection of PBMC with ΔlspA reduced HIV infectivity of CD4+ T cells by 40% relative to BCG-infected cells (p<0.05). These results may have important implications for TB vaccination programs in areas with high mother-to-child HIV transmission.

  13. Using Fluorescent Viruses for Detecting Bacteria in Water

    Science.gov (United States)

    Tabacco, Mary Beth; Qian, Xiaohua; Russo, Jaimie A.

    2009-01-01

    A method of detecting water-borne pathogenic bacteria is based partly on established molecular-recognition and fluorescent-labeling concepts, according to which bacteria of a species of interest are labeled with fluorescent reporter molecules and the bacteria can then be detected by fluorescence spectroscopy. The novelty of the present method lies in the use of bacteriophages (viruses that infect bacteria) to deliver the fluorescent reporter molecules to the bacteria of the species of interest.

  14. EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies), 2014. Scientific Opinion on the substantiation of a health claim related to CranMax® and reduction of the risk of urinary tract infection by inhibiting the adhesion of certain bacteria in the urinary tract pursuant

    DEFF Research Database (Denmark)

    Tetens, Inge

    related to CranMax® and reduction of the risk of urinary tract infection by inhibiting the adhesion of certain bacteria in the urinary tract. The food that is the subject of the claim is CranMax®. The Panel considers that the food, CranMax®, which is the subject of the claim is sufficiently characterised...... in relation to the claimed effect. The Panel considers that reduction of the risk of urinary tract infection by inhibiting the adhesion of certain bacteria in the urinary tract is a beneficial physiological effect. One human study from which conclusions could be drawn for the scientific substantiation...... of the claim did not show an effect of CranMax® on reduction of the risk of urinary tract infection by inhibiting the adhesion of certain bacteria in the urinary tract. The Panel concludes that a cause and effect relationship has not been established between the consumption of CranMax® and reduction...

  15. PERK Signal-Modulated Protein Translation Promotes the Survivability of Dengue 2 Virus-Infected Mosquito Cells and Extends Viral Replication.

    Science.gov (United States)

    Hou, Jiun-Nan; Chen, Tien-Huang; Chiang, Yi-Hsuan; Peng, Jing-Yun; Yang, Tsong-Han; Cheng, Chih-Chieh; Sofiyatun, Eny; Chiu, Cheng-Hsun; Chiang-Ni, Chuan; Chen, Wei-June

    2017-09-20

    Survival of mosquitoes from dengue virus (DENV) infection is a prerequisite of viral transmission to the host. This study aimed to see how mosquito cells can survive the infection during prosperous replication of the virus. In C6/36 cells, global protein translation was shut down after infection by DENV type 2 (DENV2). However, it returned to a normal level when infected cells were treated with an inhibitor of the protein kinase RNA (PKR)-like ER kinase (PERK) signaling pathway. Based on a 7-Methylguanosine 5'-triphosphate (m7GTP) pull-down assay, the eukaryotic translation initiation factor 4F (eIF4F) complex was also identified in DENV2-infected cells. This suggests that most mosquito proteins are synthesized via canonical cap-dependent translation. When the PERK signal pathway was inhibited, both accumulation of reactive oxygen species and changes in the mitochondrial membrane potential increased. This suggested that ER stress response was alleviated through the PERK-mediated shutdown of global proteins in DENV2-infected C6/36 cells. In the meantime, the activities of caspases-9 and -3 and the apoptosis-related cell death rate increased in C6/36 cells with PERK inhibition. This reflected that the PERK-signaling pathway is involved in determining cell survival, presumably by reducing DENV2-induced ER stress. Looking at the PERK downstream target, α-subunit of eukaryotic initiation factor 2 (eIF2α), an increased phosphorylation status was only shown in infected C6/36 cells. This indicated that recruitment of ribosome binding to the mRNA 5'-cap structure could have been impaired in cap-dependent translation. It turned out that shutdown of cellular protein translation resulted in a pro-survival effect on mosquito cells in response to DENV2 infection. As synthesis of viral proteins was not affected by the PERK signal pathway, an alternate mode other than cap-dependent translation may be utilized. This finding provides insights into elucidating how the PERK signal

  16. Epstein-Barr virus ensures B cell survival by uniquely modulating apoptosis at early and late times after infection.

    Science.gov (United States)

    Price, Alexander M; Dai, Joanne; Bazot, Quentin; Patel, Luv; Nikitin, Pavel A; Djavadian, Reza; Winter, Peter S; Salinas, Cristina A; Barry, Ashley Perkins; Wood, Kris C; Johannsen, Eric C; Letai, Anthony; Allday, Martin J; Luftig, Micah A

    2017-04-20

    Latent Epstein-Barr virus (EBV) infection is causally linked to several human cancers. EBV expresses viral oncogenes that promote cell growth and inhibit the apoptotic response to uncontrolled proliferation. The EBV oncoprotein LMP1 constitutively activates NFκB and is critical for survival of EBV-immortalized B cells. However, during early infection EBV induces rapid B cell proliferation with low levels of LMP1 and little apoptosis. Therefore, we sought to define the mechanism of survival in the absence of LMP1/NFκB early after infection. We used BH3 profiling to query mitochondrial regulation of apoptosis and defined a transition from uninfected B cells (BCL-2) to early-infected (MCL-1/BCL-2) and immortalized cells (BFL-1). This dynamic change in B cell survival mechanisms is unique to virus-infected cells and relies on regulation of MCL-1 mitochondrial localization and BFL-1 transcription by the viral EBNA3A protein. This study defines a new role for EBNA3A in the suppression of apoptosis with implications for EBV lymphomagenesis.

  17. Mycobacterium tuberculosis controls microRNA-99b (miR-99b) expression in infected murine dendritic cells to modulate host immunity.

    Science.gov (United States)

    Singh, Yogesh; Kaul, Vandana; Mehra, Alka; Chatterjee, Samit; Tousif, Sultan; Dwivedi, Ved Prakash; Suar, Mrutyunjay; Van Kaer, Luc; Bishai, William R; Das, Gobardhan

    2013-02-15

    Mycobacterium tuberculosis resides and replicates within host phagocytes by modulating host microbicidal responses. In addition, it suppresses the production of host protective cytokines to prevent activation of and antigen presentation by M. tuberculosis-infected cells, causing dysregulation of host protective adaptive immune responses. Many cytokines are regulated by microRNAs (miRNAs), a newly discovered class of small noncoding RNAs, which have been implicated in modulating host immune responses in many bacterial and viral diseases. Here, we show that miRNA-99b (miR-99b), an orphan miRNA, plays a key role in the pathogenesis of M. tuberculosis infection. We found that miR-99b expression was highly up-regulated in M. tuberculosis strain H37Rv-infected dendritic cells (DCs) and macrophages. Blockade of miR-99b expression by antagomirs resulted in significantly reduced bacterial growth in DCs. Interestingly, knockdown of miR-99b in DCs significantly up-regulated proinflammatory cytokines such as IL-6, IL-12, and IL-1β. Furthermore, mRNA and membrane-bound protein data indicated that inhibition of miR-99b augments TNF-α and TNFRSF-4 production. Thus, miR-99b targets TNF-α and TNFRSF-4 receptor genes. Treatment of anti-miR-99b-transfected DCs with anti-TNF-α antibody resulted in increased bacterial burden. Thus, our findings unveil a novel host evasion mechanism adopted by M. tuberculosis via miR-99b, which may open up new avenues for designing miRNA-based vaccines and therapies.

  18. Mycobacterium tuberculosis Controls MicroRNA-99b (miR-99b) Expression in Infected Murine Dendritic Cells to Modulate Host Immunity*

    Science.gov (United States)

    Singh, Yogesh; Kaul, Vandana; Mehra, Alka; Chatterjee, Samit; Tousif, Sultan; Dwivedi, Ved Prakash; Suar, Mrutyunjay; Van Kaer, Luc; Bishai, William R.; Das, Gobardhan

    2013-01-01

    Mycobacterium tuberculosis resides and replicates within host phagocytes by modulating host microbicidal responses. In addition, it suppresses the production of host protective cytokines to prevent activation of and antigen presentation by M. tuberculosis-infected cells, causing dysregulation of host protective adaptive immune responses. Many cytokines are regulated by microRNAs (miRNAs), a newly discovered class of small noncoding RNAs, which have been implicated in modulating host immune responses in many bacterial and viral diseases. Here, we show that miRNA-99b (miR-99b), an orphan miRNA, plays a key role in the pathogenesis of M. tuberculosis infection. We found that miR-99b expression was highly up-regulated in M. tuberculosis strain H37Rv-infected dendritic cells (DCs) and macrophages. Blockade of miR-99b expression by antagomirs resulted in significantly reduced bacterial growth in DCs. Interestingly, knockdown of miR-99b in DCs significantly up-regulated proinflammatory cytokines such as IL-6, IL-12, and IL-1β. Furthermore, mRNA and membrane-bound protein data indicated that inhibition of miR-99b augments TNF-α and TNFRSF-4 production. Thus, miR-99b targets TNF-α and TNFRSF-4 receptor genes. Treatment of anti-miR-99b-transfected DCs with anti-TNF-α antibody resulted in increased bacterial burden. Thus, our findings unveil a novel host evasion mechanism adopted by M. tuberculosis via miR-99b, which may open up new avenues for designing miRNA-based vaccines and therapies. PMID:23233675

  19. Trypanosomatid Infections: How Do Parasites and Their Excreted–Secreted Factors Modulate the Inducible Metabolism of l-Arginine in Macrophages?

    Directory of Open Access Journals (Sweden)

    Philippe Holzmuller

    2018-04-01

    Full Text Available Mononuclear phagocytes (monocytes, dendritic cells, and macrophages are among the first host cells to face intra- and extracellular protozoan parasites such as trypanosomatids, and significant expansion of macrophages has been observed in infected hosts. They play essential roles in the outcome of infections caused by trypanosomatids, as they can not only exert a powerful antimicrobial activity but also promote parasite proliferation. These varied functions, linked to their phenotypic and metabolic plasticity, are exerted via distinct activation states, in which l-arginine metabolism plays a pivotal role. Depending on the environmental factors and immune response elements, l-arginine metabolites contribute to parasite elimination, mainly through nitric oxide (NO synthesis, or to parasite proliferation, through l-ornithine and polyamine production. To survive and adapt to their hosts, parasites such as trypanosomatids developed mechanisms of interaction to modulate macrophage activation in their favor, by manipulating several cellular metabolic pathways. Recent reports emphasize that some excreted–secreted (ES molecules from parasites and sugar-binding host receptors play a major role in this dialog, particularly in the modulation of the macrophage’s inducible l-arginine metabolism. Preventing l-arginine dysregulation by drugs or by immunization against trypanosomatid ES molecules or by blocking partner host molecules may control early infection and is a promising way to tackle neglected diseases including Chagas disease, leishmaniases, and African trypanosomiases. The present review summarizes recent knowledge on trypanosomatids and their ES factors with regard to their influence on macrophage activation pathways, mainly the NO synthase/arginase balance. The review ends with prospects for the use of biological knowledge to develop new strategies of interference in the infectious processes used by trypanosomatids, in particular for the

  20. Rumen bacteria

    International Nuclear Information System (INIS)

    McSweeney, C.S.; Denman, S.E.; Mackie, R.I.

    2005-01-01

    The rumen is the most extensively studied gut community and is characterized by its high population density, wide diversity and complexity of interactions. This complex, mixed microbial culture is comprised of prokaryote organisms including methane-producing archaebacteria, eukaryote organisms, such as ciliate and flagellate protozoa, anaerobic phycomycete fungi and bacteriophage. Bacteria are predominant (up to 10 11 viable cells per g comprising 200 species) but a variety of ciliate protozoa occur widely (10 4 -10 6 /g distributed over 25 genera). The anaerobic fungi are also widely distributed (zoospore population densities of 10 2 -10 4 /g distributed over 5 genera). The occurrence of bacteriophage is well documented (10 7 -10 9 particles/g). This section focuses primarily on the widely used methods for the cultivation and the enumeration of rumen microbes, especially bacteria, which grow under anaerobic conditions. Methods that can be used to measure hydrolytic enzymes (cellulases, xylanases, amylases and proteinases) are also described, along with cell harvesting and fractionation procedures. Brief reference is also made to fungi and protozoa, but detailed explanations for culturing and enumerating these microbes is presented in Chapters 2.4 and 2.5

  1. The alternative sigma factor sigma B of Staphylococcus aureus modulates virulence in experimental central venous catheter-related infections.

    Science.gov (United States)

    Lorenz, Udo; Hüttinger, Christian; Schäfer, Tina; Ziebuhr, Wilma; Thiede, Arnulf; Hacker, Jörg; Engelmann, Susanne; Hecker, Michael; Ohlsen, Knut

    2008-03-01

    The impact of the alternative sigma factor sigma B (SigB) on pathogenesis of Staphylococcus aureus is not conclusively clarified. In this study, a central venous catheter (CVC) related model of multiorgan infection was used to investigate the role of SigB for the pathogenesis of S. aureus infections and biofilm formation in vivo. Analysis of two SigB-positive wild-type strains and their isogenic mutants revealed uniformly that the wild-type was significantly more virulent than the SigB-deficient mutant. The observed difference in virulence was apparently not linked to the capability of the strains to form biofilms in vivo since wild-type and mutant strains were able to produce biofilm layers inside of the catheter. The data strongly indicate that the alternative sigma factor SigB plays a role in CVC-associated infections caused by S. aureus.

  2. TLR2-Modulating Lipoproteins of the Mycobacterium tuberculosis Complex Enhance the HIV Infectivity of CD4+ T Cells.

    Directory of Open Access Journals (Sweden)

    Ciaran Skerry

    Full Text Available Co-infection with Mycobacterium tuberculosis accelerates progression from HIV to AIDS. Our previous studies showed that M. tuberculosis complex, unlike M. smegmatis, enhances TLR2-dependent susceptibility of CD4+ T cells to HIV. The M. tuberculosis complex produces multiple TLR2-stimulating lipoproteins, which are absent in M. smegmatis. M. tuberculosis production of mature lipoproteins and TLR2 stimulation is dependent on cleavage by lipoprotein signal peptidase A (LspA. In order to determine the role of potential TLR2-stimulating lipoproteins on mycobacterial-mediated HIV infectivity of CD4+ T cells, we generated M. smegmatis recombinant strains overexpressing genes encoding various M. bovis BCG lipoproteins, as well as a Mycobacterium bovis BCG strain deficient in LspA (ΔlspA. Exposure of human peripheral blood mononuclear cells (PBMC to M. smegmatis strains overexpressing the BCG lipoproteins, LprF (p<0.01, LprH (p<0.05, LprI (p<0.05, LprP (p<0.001, LprQ (p<0.005, MPT83 (p<0.005, or PhoS1 (p<0.05, resulted in increased HIV infectivity of CD4+ T cells isolated from these PBMC. Conversely, infection of PBMC with ΔlspA reduced HIV infectivity of CD4+ T cells by 40% relative to BCG-infected cells (p<0.05. These results may have important implications for TB vaccination programs in areas with high mother-to-child HIV transmission.

  3. Common Duckweed (Lemna minor) Is a Versatile High-Throughput Infection Model For the Burkholderia cepacia Complex and Other Pathogenic Bacteria

    Science.gov (United States)

    Thomson, Euan L. S.; Dennis, Jonathan J.

    2013-01-01

    Members of the Burkholderia cepacia complex (Bcc) have emerged in recent decades as problematic pulmonary pathogens of cystic fibrosis (CF) patients, with severe infections progressing to acute necrotizing pneumonia and sepsis. This study presents evidence that Lemna minor (Common duckweed) is useful as a plant model for the Bcc infectious process, and has potential as a model system for bacterial pathogenesis in general. To investigate the relationship between Bcc virulence in duckweed and Galleria mellonella (Greater wax moth) larvae, a previously established Bcc infection model, a duckweed survival assay was developed and used to determine LD50 values. A strong correlation (R2 = 0.81) was found between the strains’ virulence ranks in the two infection models, suggesting conserved pathways in these vastly different hosts. To broaden the application of the duckweed model, enteropathogenic Escherichia coli (EPEC) and five isogenic mutants with previously established LD50 values in the larval model were tested against duckweed, and a strong correlation (R2 = 0.93) was found between their raw LD50 values. Potential virulence factors in B. cenocepacia K56-2 were identified using a high-throughput screen against single duckweed plants. In addition to the previously characterized antifungal compound (AFC) cluster genes, several uncharacterized genes were discovered including a novel lysR regulator, a histidine biosynthesis gene hisG, and a gene located near the gene encoding the recently characterized virulence factor SuhBBc. Finally, to demonstrate the utility of this model in therapeutic applications, duckweed was rescued from Bcc infection by treating with bacteriophage at 6-h intervals. It was observed that phage application became ineffective at a timepoint that coincided with a sharp increase in bacterial invasion of plant tissue. These results indicate that common duckweed can serve as an effective infection model for the investigation of bacterial virulence

  4. Common duckweed (Lemna minor is a versatile high-throughput infection model for the Burkholderia cepacia complex and other pathogenic bacteria.

    Directory of Open Access Journals (Sweden)

    Euan L S Thomson

    Full Text Available Members of the Burkholderia cepacia complex (Bcc have emerged in recent decades as problematic pulmonary pathogens of cystic fibrosis (CF patients, with severe infections progressing to acute necrotizing pneumonia and sepsis. This study presents evidence that Lemna minor (Common duckweed is useful as a plant model for the Bcc infectious process, and has potential as a model system for bacterial pathogenesis in general. To investigate the relationship between Bcc virulence in duckweed and Galleria mellonella (Greater wax moth larvae, a previously established Bcc infection model, a duckweed survival assay was developed and used to determine LD50 values. A strong correlation (R(2 = 0.81 was found between the strains' virulence ranks in the two infection models, suggesting conserved pathways in these vastly different hosts. To broaden the application of the duckweed model, enteropathogenic Escherichia coli (EPEC and five isogenic mutants with previously established LD50 values in the larval model were tested against duckweed, and a strong correlation (R(2 = 0.93 was found between their raw LD50 values. Potential virulence factors in B. cenocepacia K56-2 were identified using a high-throughput screen against single duckweed plants. In addition to the previously characterized antifungal compound (AFC cluster genes, several uncharacterized genes were discovered including a novel lysR regulator, a histidine biosynthesis gene hisG, and a gene located near the gene encoding the recently characterized virulence factor SuhB(Bc. Finally, to demonstrate the utility of this model in therapeutic applications, duckweed was rescued from Bcc infection by treating with bacteriophage at 6-h intervals. It was observed that phage application became ineffective at a timepoint that coincided with a sharp increase in bacterial invasion of plant tissue. These results indicate that common duckweed can serve as an effective infection model for the investigation of bacterial

  5. The Central Conserved Region (CCR) of Respiratory Syncytial Virus (RSV) G Protein Modulates Host miRNA Expression and Alters the Cellular Response to Infection.

    Science.gov (United States)

    Bakre, Abhijeet A; Harcourt, Jennifer L; Haynes, Lia M; Anderson, Larry J; Tripp, Ralph A

    2017-07-03

    Respiratory Syncytial Virus (RSV) infects respiratory epithelial cells and deregulates host gene expression by many mechanisms including expression of RSV G protein (RSV G). RSV G protein encodes a central conserved region (CCR) containing a CX3C motif that functions as a fractalkine mimic. Disruption of the CX3C motif (a.a. 182-186) located in the CCR of the G protein has been shown to affect G protein function in vitro and the severity of RSV disease pathogenesis in vivo. We show that infection of polarized Calu3 respiratory cells with recombinant RSV having point mutations in Cys173 and 176 (C173/176S) (rA2-GC12), or Cys186 (C186S) (rA2-GC4) is associated with a decline in the integrity of polarized Calu-3 cultures and decreased virus production. This is accompanied with downregulation of miRNAs let-7f and miR-24 and upregulation of interferon lambda (IFNλ), a primary antiviral cytokine for RSV in rA2-GC12/rA2-GC4 infected cells. These results suggest that residues in the cysteine noose region of RSV G protein can modulate IFN λ expression accompanied by downregulation of miRNAs, and are important for RSV G protein function and targeting.

  6. Cross-talk interactions of exogenous nitric oxide and sucrose modulates phenylpropanoid metabolism in yellow lupine embryo axes infected with Fusarium oxysporum.

    Science.gov (United States)

    Morkunas, Iwona; Formela, Magda; Floryszak-Wieczorek, Jolanta; Marczak, Łukasz; Narożna, Dorota; Nowak, Witold; Bednarski, Waldemar

    2013-10-01

    The aim of the study was to examine cross-talk of exogenous nitric oxide (NO) and sucrose in the mechanisms of synthesis and accumulation of isoflavonoids in embryo axes of Lupinus luteus L. cv. Juno. It was verified whether the interaction of these molecules can modulate the defense response of axes to infection and development of the pathogenic fungus Fusarium oxysporum f. sp. lupini. Sucrose alone strongly stimulated a high level of genistein glucoside in axes pretreated with exogenous nitric oxide (SNP or GSNO) and non-pretreated axes. As a result of amplification of the signal coming from sucrose and GSNO, high isoflavonoids accumulation was observed (+Sn+GSNO). It needs to be stressed that infection in tissues pretreated with SNP/GSNO and cultured on the medium with sucrose (+Si+SNP/+Si+GSNO) very strongly enhances the accumulation of free isoflavone aglycones. In +Si+SNP axes phenylalanine ammonia-lyase activity was high up to 72h. As early as at 12h in +Si+SNP axes an increase was recorded in gene expression level of the specific isoflavonoid synthesis pathway. At 24h in +Si+SNP axes a very high total antioxidant capacity dependent on the pool of fast antioxidants was noted. Post-infection generation of semiquinone radicals was lower in axes with a high level of sucrose than with a deficit. Copyright © 2013 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  7. Zika Virus Infects Human Sertoli Cells and Modulates the Integrity of the In Vitro Blood-Testis Barrier Model.

    Science.gov (United States)

    Siemann, David N; Strange, Daniel P; Maharaj, Payal N; Shi, Pei-Yong; Verma, Saguna

    2017-11-15

    Confirmed reports of Zika virus (ZIKV) in human seminal fluid for months after the clearance of viremia suggest the ability of ZIKV to establish persistent infection in the seminiferous tubules, an immune-privileged site in the testis protected by the blood-testis barrier, also called the Sertoli cell (SC) barrier (SCB). However, cellular targets of ZIKV in human testis and mechanisms by which the virus enters seminiferous tubules remain unclear. We demonstrate that primary human SCs were highly susceptible to ZIKV compared to the closely related dengue virus and induced the expression of alpha interferon (IFN-α), key cytokines, and cell adhesion molecules (vascular cell adhesion molecule 1 [VCAM-1] and intracellular adhesion molecule 1 [ICAM-1]). Furthermore, using an in vitro SCB model, we show that ZIKV was released on the adluminal side of the SCB model with a higher efficiency than in the blood-brain barrier model. ZIKV-infected SCs exhibited enhanced adhesion of leukocytes that correlated with decreases in SCB integrity. ZIKV infection did not affect the expression of tight and adherens junction proteins such as ZO-1, claudin, and JAM-A; however, exposure of SCs to inflammatory mediators derived from ZIKV-infected macrophages led to the degradation of the ZO-1 protein, which correlated with increased SCB permeability. Taken together, our data suggest that infection of SCs may be one of the crucial steps by which ZIKV gains access to the site of spermatozoon development and identify SCs as a therapeutic target to clear testicular infections. The SCB model opens up opportunities to assess interactions of SCs with other testicular cells and to test the ability of anti-ZIKV drugs to cross the barrier. IMPORTANCE Recent outbreaks of ZIKV, a neglected mosquito-borne flavivirus, have identified sexual transmission as a new route of disease spread, which has not been reported for other flaviviruses. To be able to sexually transmit for months after the clearance of

  8. CXCR1/2 Antagonism Is Protective during Influenza and Post-Influenza Pneumococcal Infection

    Directory of Open Access Journals (Sweden)

    Luciana P. Tavares

    2017-12-01

    Full Text Available RationaleInfluenza A infections are a leading cause of morbidity and mortality worldwide especially when associated with secondary pneumococcal infections. Inflammation is important to control pathogen proliferation but may also cause tissue injury and death. CXCR1/2 are chemokine receptors relevant for the recruitment of neutrophils. We investigated the role of CXCR1/2 during influenza, pneumococcal, and post-influenza pneumococcal infections.MethodsMice were infected with influenza A virus (IAV or Streptococcus pneumoniae and then treated daily with the CXCR1/2 antagonist DF2162. To study secondary pneumococcal infection, mice were infected with a sublethal inoculum of IAV then infected with S. pneumoniae 14 days later. DF2162 was given in a therapeutic schedule from days 3 to 6 after influenza infection. Lethality, weight loss, inflammation, virus/bacteria counts, and lung injury were assessed.ResultsCXCL1 and CXCL2 were produced at high levels during IAV infection. DF2162 treatment decreased morbidity and this was associated with decreased infiltration of neutrophils in the lungs and reduced pulmonary damage and viral titers. During S. pneumoniae infection, DF2162 treatment decreased neutrophil recruitment, pulmonary damage, and lethality rates, without affecting bacteria burden. Therapeutic treatment with DF2162 during sublethal IAV infection reduced the morbidity associated with virus infection and also decreased the magnitude of inflammation, lung damage, and number of bacteria in the blood of mice subsequently infected with S. pneumoniae.ConclusionModulation of the inflammatory response by blocking CXCR1/2 improves disease outcome during respiratory influenza and pneumococcal infections, without compromising the ability of the murine host to deal with infection. Altogether, inhibition of CXCR1/2 may be a valid therapeutic strategy for treating lung infections caused by these pathogens, especially controlling secondary bacterial

  9. Dual function of CD70 in viral infection: modulator of early cytokine responses and activator of adaptive responses1

    Science.gov (United States)

    Allam, Atef; Swiecki, Melissa; Vermi, William; Ashwell, Jonathan D.; Colonna, Marco

    2014-01-01

    The role of the tumor necrosis factor family member CD70 in adaptive T cell responses has been intensively studied but its function in innate responses is still under investigation. Here we show that CD70 inhibits the early innate response to murine cytomegalovirus (MCMV) but is essential for the optimal generation of virus-specific CD8 T cells. CD70-/- mice reacted to MCMV infection with a robust type I interferon and proinflammatory cytokine response. This response was sufficient for initial control of MCMV, although at later time points, CD70-/- mice became more susceptible to MCMV infection. The heightened cytokine response during the early phase of MCMV infection in CD70-/- mice was paralleled by a reduction in regulatory T cells (Treg). Treg from naïve CD70-/- mice were not as efficient at suppressing T cell proliferation compared to Treg from naïve WT mice and depletion of Treg during MCMV infection in Foxp3-DTR mice or in WT mice recapitulated the phenotype observed in CD70-/- mice. Our study demonstrates that while CD70 is required for the activation of the antiviral adaptive response, it has a regulatory role in early cytokine responses to viruses such as MCMV, possibly through maintenance of Treg survival and function. PMID:24913981

  10. Modulation of Quorum Sensing in a Gram Positive Pathogen by Linear Imprinted Copolymers with anti-Infective Properties

    NARCIS (Netherlands)

    Motib, Anfal; Guerreiro, Antonio; Al-Bayati, Firas; Piletska, Elena; Manzoor, Irfan; Shafeeq, Sulman; Kadam, Anagha; Kuipers, Oscar; Hiller, Luisa; Cowen, Todd; Piletsky, Sergey; Andrew, Peter; Yesilkaya, Hasan

    2017-01-01

    Here we describe the development, characterization and biological testing of a new type of linear molecularly imprinted polymer (LMIP) designed to act as anti-infective by blocking the quorum sensing (QS) mechanism and so preventing virulence of the pathogen Streptococcus pneumoniae. The LMIP is

  11. High-protein enteral nutrition enriched with immune-modulating nutrients vs standard high-protein enteral nutrition and nosocomial infections in the ICU: a randomized clinical trial.

    Science.gov (United States)

    van Zanten, Arthur R H; Sztark, François; Kaisers, Udo X; Zielmann, Siegfried; Felbinger, Thomas W; Sablotzki, Armin R; De Waele, Jan J; Timsit, Jean-François; Honing, Marina L H; Keh, Didier; Vincent, Jean-Louis; Zazzo, Jean-Fabien; Fijn, Harvey B M; Petit, Laurent; Preiser, Jean-Charles; van Horssen, Peter J; Hofman, Zandrie

    2014-08-06

    Enteral administration of immune-modulating nutrients (eg, glutamine, omega-3 fatty acids, selenium, and antioxidants) has been suggested to reduce infections and improve recovery from critical illness. However, controversy exists on the use of immune-modulating enteral nutrition, reflected by lack of consensus in guidelines. To determine whether high-protein enteral nutrition enriched with immune-modulating nutrients (IMHP) reduces the incidence of infections compared with standard high-protein enteral nutrition (HP) in mechanically ventilated critically ill patients. The MetaPlus study, a randomized, double-blind, multicenter trial, was conducted from February 2010 through April 2012 including a 6-month follow-up period in 14 intensive care units (ICUs) in the Netherlands, Germany, France, and Belgium. A total of 301 adult patients who were expected to be ventilated for more than 72 hours and to require enteral nutrition for more than 72 hours were randomized to the IMHP (n = 152) or HP (n = 149) group and included in an intention-to-treat analysis, performed for the total population as well as predefined medical, surgical, and trauma subpopulations. High-protein enteral nutrition enriched with immune-modulating nutrients vs standard high-protein enteral nutrition, initiated within 48 hours of ICU admission and continued during the ICU stay for a maximum of 28 days. The primary outcome measure was incidence of new infections according to the Centers for Disease Control and Prevention (CDC) definitions. Secondary end points included mortality, Sequential Organ Failure Assessment (SOFA) scores, mechanical ventilation duration, ICU and hospital lengths of stay, and subtypes of infections according CDC definitions. There were no statistically significant differences in incidence of new infections between the groups: 53% (95% CI, 44%-61%) in the IMHP group vs 52% (95% CI, 44%-61%) in the HP group (P = .96). No statistically significant differences were

  12. Urinary Tract Infections (For Kids)

    Medline Plus

    Full Text Available ... Your pee smells bad. These things happen because bacteria have caused an infection somewhere in your urinary ... shorter than boys' urethras. The shorter urethra means bacteria can get up into the bladder more easily ...

  13. Effects of co-occurring Wolbachia and Spiroplasma endosymbionts on the Drosophila immune response against insect pathogenic and non-pathogenic bacteria.

    Science.gov (United States)

    Shokal, Upasana; Yadav, Shruti; Atri, Jaishri; Accetta, Julia; Kenney, Eric; Banks, Katherine; Katakam, Akash; Jaenike, John; Eleftherianos, Ioannis

    2016-02-09

    Symbiotic interactions between microbes and animals are common in nature. Symbiotic organisms are particularly common in insects and, in some cases, they may protect their hosts from pathogenic infections. Wolbachia and Spiroplasma endosymbionts naturally inhabit various insects including Drosophila melanogaster fruit flies. Therefore, this symbiotic association is considered an excellent model to investigate whether endosymbiotic bacteria participate in host immune processes against certain pathogens. Here we have investigated whether the presence of Wolbachia alone or together with Spiroplasma endosymbionts in D. melanogaster adult flies affects the immune response against the virulent insect pathogen Photorhabdus luminescens and against non-pathogenic Escherichia coli bacteria. We found that D. melanogaster flies carrying no endosymbionts, those carrying both Wolbachia and Spiroplasma, and those containing Wolbachia only had similar survival rates after infection with P. luminescens or Escherichia coli bacteria. However, flies carrying both endosymbionts or Wolbachia only contained higher numbers of E. coli cells at early time-points post infection than flies without endosymbiotic bacteria. Interestingly, flies containing Wolbachia only had lower titers of this endosymbiont upon infection with the pathogen P. luminescens than uninfected flies of the same strain. We further found that the presence of Wolbachia and Spiroplasma in D. melanogaster up-regulated certain immune-related genes upon infection with P. luminescens or E. coli bacteria, but it failed to alter the phagocytic ability of the flies toward E. coli inactive bioparticles. Our results suggest that the presence of Wolbachia and Spiroplasma in D. melanogaster can modulate immune signaling against infection by certain insect pathogenic and non-pathogenic bacteria. Results from such studies are important for understanding the molecular basis of the interactions between endosymbiotic bacteria of insects

  14. Understanding Wolbachia acquisition and co-divergence of hosts and their associated bacteria: Wolbachia infection in the Chorthippus parallelus hybrid zone

    OpenAIRE

    Paloma, Martinez-Rodriguez; Luis, Bella; Francisca, Arroyo-Yebras

    2016-01-01

    Wolbachia is one of the best known bacterial endosymbionts affecting insects and nematodes. It is estimated that it infects 40% of insect species, so epidemiologically it may be considered a pandemic species. However, the mechanisms by which it is acquired from other species (horizontal transmission) or by which it coevolves with its hosts as a result of vertical transmission across generations are not known in detail. In fact, there are few systems in which the codivergence between host and ...

  15. The Potential Application and Risks Associated With the Use of Predatory Bacteria as a Bio-control Agent Against Wound Infections

    Science.gov (United States)

    2015-10-01

    213: 428–431. 21. Dwidar M, Monnappa AK, Mitchell RJ (2012) The dual probiotic and antibiotic nature of Bdellovibrio bacteriovorus. BMB Rep 45: 71–78...and characterization of two bacteriophages with strong in vitro antimicrobial activity against Pseudomonas aeruginosa isolated from dogs with ocular...infections. Am J Vet Res 72: 1079–1086. 4. Dwidar M, Monnappa AK, Mitchell RJ (2012) The dual probiotic and antibiotic nature of Bdellovibrio

  16. In vitro comparison between α-tocopheryl acetate and α-tocopheryl phosphate against bacteria responsible of prosthetic and joint infections.

    Directory of Open Access Journals (Sweden)

    Alessandro Bidossi

    Full Text Available Biofilm-related infections represent a recurrent problem in the orthopaedic setting. In recent years, great interest was directed towards the identification of novel molecules capable to interfere with pathogens adhesion and biofilm formation on implant surfaces. In this study, two stable forms of α-tocopherol, the hydrophobic acetate ester and the water-soluble phosphate ester, were tested in vitro as coating for titanium prosthesis. Antimicrobial activity against microorganisms responsible of prosthetic and joints infections was assessed by broth microdilution method. In addition, α-tocopherol esters were evaluated for both their ability to hamper bacterial adhesion to and biofilm formation on sandblasted titanium surfaces. Results showed that only α-tocopheryl phosphate displayed antimicrobial activity against the tested strains. Both esters were able to significantly interfere with bacterial adhesion and to prevent biofilm formation, especially by Staphylococcus aureus and Staphylococcus epidermidis. The activity of α-tocopheryl phosphate was greater than that of α-tocopheryl acetate. Alterations at membrane levels have been reported in literature and may be likely responsible for the interference on bacterial adhesion and biofilm formation shown by α-tocopherol esters. Although further studies are needed to better investigate the mechanisms of action and the spectrum of activity of α-tocopherol esters, these characteristics together with the positive effect on wound healing and immune response, make these molecules promising candidate for coating in order to prevent implant-associated infections.

  17. Viable Legionella pneumophila bacteria in natural soil and rainwater puddles

    NARCIS (Netherlands)

    van Heijnsbergen, E.; de Roda Husman, A. M.; Lodder, W. J.; Bouwknegt, M.; Docters van Leeuwen, A. E.; Bruin, J. P.; Euser, S. M.; den Boer, J. W.; Schalk, J. A C

    Aims: For the majority of sporadic Legionnaires' disease cases the source of infection remains unknown. Infection may possible result from exposure to Legionella bacteria in sources that are not yet considered in outbreak investigations. Therefore, potential sources of pathogenic Legionella

  18. Mathematical studies on nosocomial spread of antibiotic-resistant bacteria

    NARCIS (Netherlands)

    Gurieva, T.V.

    2017-01-01

    Infections with antibiotic-resistant bacteria are a worldwide problem in hospitals and their rates remain high in many countries despite efforts to reduce the rates. Infection prevention is complicated by asymptomatic carriers. Using mathematical modelling, different intervention strategies were

  19. Puerperal infections.

    Science.gov (United States)

    Eschenbach, D A; Wager, G P

    1980-12-01

    This comprehensive review on puerperal infections covers risk factors, causative bacteria, pathophysiology, diagnosis, therapy of specific entities, and prevention. Puerperal infection is problematic to define especially with antibiotics that change the course of fever. I may present as endometritis (most common), myometritis, parametritis, pelvic abscess, salpingitis, septic pelvic thrombophlebitis or septicemia, and also includes infections of the urinary tract, episiotomy, surgical wounds, lacerations or breast. Each of these is discussed in terms of contributing factors, microbiology, clinical findings, diagnosis, treatment, prevention and complications. Risk factors in general are cesarean section, premature rupture of the membranes, internal fetal monitoring, general anesthesia, pelvic examinations. The most common bacterial involved are group B and other streptococci, E. coli, Gardnerella vaginalis, Gram positive anaerobic cocci, Mycoplasma and pre-existing Chlamydial infections. Diagnosis of the causative organism is difficult because of polyinfection and difficulty of getting a sterile endometrial swab. Diagnosis of the infection is equally difficult because of the wide variety of symptoms: fever, abnormal lochia, tachycardia, tenderness, mass and abnormal bowel sounds are common. Therapy depends of the responsible microorganism, although 3 empirical tactics are suggested while awaiting results of culture: 1) choose an antibiotic for the most common aerobic bacteria; 2) an antibiotic effective against B. fragilis and one for aerobic bacteria, e.g. clindamycin and an aminoglycoside; 3) a nontoxic antibiotic active against most aerobic and anaerobic organisms, e.g. doxycycline or cefoxitin. An example of an infection recently described is pudendal-paracervical block infection, often signaled by severe hip pain. It is associated with vaginal bacteria, is usually complicated by abscess even with antibiotic coverage, and may end in paraplegia or fatal sepsis

  20. Immunization with Pseudomonas aeruginosa vaccines and adjuvant can modulate the type of inflammatory response subsequent to infection

    DEFF Research Database (Denmark)

    Johansen, H K; Espersen, F; Cryz, S J

    1994-01-01

    Pseudomonas aeruginosa is the predominant pathogen in patients with cystic fibrosis (CF). To study the possibility of preventing lung inflammation and decreasing the progression of the infection by vaccination, we have developed a rat model of chronic P. aeruginosa lung infection. Rats were......, 2.0 versus 2.1 to 2.8) pathologic abnormalities were less severe in the control rats injected with sterile saline than in the immunized rats and the IFA group. The more severe lung abnormalities observed in immunized rats could be due to the result of immune complex-mediated lung tissue damage...... an acute-type inflammation to a chronic-type inflammation dominated by mononuclear leukocytes and scattered granulomas. Cross-reacting antibodies were induced by the two alginate vaccines, and most immunized animals developed a significant (P

  1. Dual function of CD70 in viral infection: modulator of early cytokine responses and activator of adaptive responses1

    OpenAIRE

    Allam, Atef; Swiecki, Melissa; Vermi, William; Ashwell, Jonathan D.; Colonna, Marco

    2014-01-01

    The role of the tumor necrosis factor family member CD70 in adaptive T cell responses has been intensively studied but its function in innate responses is still under investigation. Here we show that CD70 inhibits the early innate response to murine cytomegalovirus (MCMV) but is essential for the optimal generation of virus-specific CD8 T cells. CD70-/- mice reacted to MCMV infection with a robust type I interferon and proinflammatory cytokine response. This response was sufficient for initia...

  2. Canine distemper virus matrix protein influences particle infectivity, particle composition, and envelope distribution in polarized epithelial cells and modulates virulence.

    Science.gov (United States)

    Dietzel, Erik; Anderson, Danielle E; Castan, Alexandre; von Messling, Veronika; Maisner, Andrea

    2011-07-01

    In paramyxoviruses, the matrix (M) protein mediates the interaction between the envelope and internal proteins during particle assembly and egress. In measles virus (MeV), M mutations, such as those found in subacute sclerosing panencephalitis (SSPE) strains, and differences in vaccine and wild-type M proteins can affect the strength of interaction with the envelope glycoproteins, assembly efficiency, and spread. However, the contribution of the M protein to the replication and pathogenesis of the closely related canine distemper virus (CDV) has not been characterized. To this end this, we generated a recombinant wild-type CDV carrying a vaccine strain M protein. The recombinant virus retained the parental growth phenotype in VerodogSLAMtag cells, but displayed an increased particle-to-infectivity ratio very similar to that of the vaccine strain, likely due to inefficient H protein incorporation. Even though infectious virus was released only from the apical surface, consistent with the release polarity of the wild-type CDV strain, envelope protein distribution in polarized epithelial cells reproduced the bipolar pattern seen in vaccine strain-infected cells. Most notably, the chimeric virus was completely attenuated in ferrets and caused only a mild and transient leukopenia, indicating that the differences in particle infectivity and envelope protein sorting mediated by the vaccine M protein contribute importantly to vaccine strain attenuation.

  3. Small Interfering RNA Pathway Modulates Initial Viral Infection in Midgut Epithelium of Insect after Ingestion of Virus.

    Science.gov (United States)

    Lan, Hanhong; Chen, Hongyan; Liu, Yuyan; Jiang, Chaoyang; Mao, Qianzhuo; Jia, Dongsheng; Chen, Qian; Wei, Taiyun

    2016-01-15

    Numerous viruses are transmitted in a persistent manner by insect vectors. Persistent viruses establish their initial infection in the midgut epithelium, from where they disseminate to the midgut visceral muscles. Although propagation of viruses in insect vectors can be controlled by the small interfering RNA (siRNA) antiviral pathway, whether the siRNA pathway can control viral dissemination from the midgut epithelium is unknown. Infection by a rice virus (Southern rice black streaked dwarf virus [SRBSDV]) of its incompetent vector (the small brown planthopper [SBPH]) is restricted to the midgut epithelium. Here, we show that the siRNA pathway is triggered by SRBSDV infection in continuously cultured cells derived from the SBPH and in the midgut of the intact insect. Knockdown of the expression of the core component Dicer-2 of the siRNA pathway by RNA interference strongly increased the ability of SRBSDV to propagate in continuously cultured SBPH cells and in the midgut epithelium, allowing viral titers in the midgut epithelium to reach the threshold (1.99 × 10(9) copies of the SRBSDV P10 gene/μg of midgut RNA) needed for viral dissemination into the SBPH midgut muscles. Our results thus represent the first elucidation of the threshold for viral dissemination from the insect midgut epithelium. Silencing of Dicer-2 further facilitated the transmission of SRBSDV into rice plants by SBPHs. Taken together, our results reveal the new finding that the siRNA pathway can control the initial infection of the insect midgut epithelium by a virus, which finally affects the competence of the virus's vector. Many viral pathogens that cause significant global health and agricultural problems are transmitted via insect vectors. The first bottleneck in viral infection, the midgut epithelium, is a principal determinant of the ability of an insect species to transmit a virus. Southern rice black streaked dwarf virus (SRBSDV) is restricted exclusively to the midgut epithelium of an

  4. Medicinal Plants Used by a Mbyá-Guarani Tribe Against Infections: Activity on KPC-Producing Isolates and Biofilm-Forming Bacteria.

    Science.gov (United States)

    Brandelli, Clara Lia Costa; Ribeiro, Vanessa Bley; Zimmer, Karine Rigon; Barth, Afonso Luís; Tasca, Tiana; Macedo, Alexandre José

    2015-11-01

    The traditional use of medicinal plants for treatment of infectious diseases by an indigenous Mbyá-Guarani tribe from South Brazil was assessed by evaluating the antibiotic and antibiofilm activities against relevant bacterial pathogens. Aqueous extracts from 10 medicinal plants were prepared according to indigenous Mbyá-Guarani traditional uses. To evaluate antibiotic (OD600) and antibiofilm (crystal violet method) activities, Pseudomonas aeruginosa ATCC 27853, Staphylococcus epidermidis ATCC 35984 and seven multi-drug resistant Klebsiella pneumoniae carbapenemase (KPC)-producing bacterial clinical isolates were challenged with the extracts. Furthermore, the susceptibility profile of KPC-producing bacteria and the ability of these isolates to form biofilm were evaluated. The plants Campomanesia xanthocarpa, Maytenus ilicifolia, Bidens pilosa and Verbena sp. showed the best activity against bacterial growth and biofilm formation. The majority of KPC-producing isolates, which showed strong ability to form biofilm and a multidrug resistance profile, was inhibited by more than 50% by some extracts. The Enterobacter cloacae (KPC 05) clinical isolate was the only one resistant to all extracts. This study confirms the importance of indigenous traditional medicinal knowledge and describes for the first time the ability of these plants to inhibit biofilm formation and/or bacterial growth of multi-drug resistant KPC-producing isolates.

  5. Campylobacter Infections

    Science.gov (United States)

    ... contact with fecal matter (poop) from an infected person (especially a child in diapers). Household pets can carry and spread the bacteria to people. ... preparing food. Clean and disinfect toilets after the person with diarrhea uses them. Also, if a pet dog or cat has diarrhea, wash your hands ...

  6. The 5' untranslated region of a novel infectious molecular clone of the dicistrovirus cricket paralysis virus modulates infection.

    Science.gov (United States)

    Kerr, Craig H; Wang, Qing S; Keatings, Kathleen; Khong, Anthony; Allan, Douglas; Yip, Calvin K; Foster, Leonard J; Jan, Eric

    2015-06-01

    Dicistroviridae are a family of RNA viruses that possesses a single-stranded positive-sense RNA genome containing two distinct open reading frames (ORFs), each preceded by an internal ribosome entry site that drives translation of the viral structural and nonstructural proteins, respectively. The type species, Cricket paralysis virus (CrPV), has served as a model for studying host-virus interactions; however, investigations into the molecular mechanisms of CrPV and other dicistroviruses have been limited as an established infectious clone was elusive. Here, we report the construction of an infectious molecular clone of CrPV. Transfection of in vitro-transcribed RNA from the CrPV clone into Drosophila Schneider line 2 (S2) cells resulted in cytopathic effects, viral RNA accumulation, detection of negative-sense viral RNA, and expression of viral proteins. Transmission electron microscopy, viral titers, and immunofluorescence-coupled transwell assays demonstrated that infectious viral particles are released from transfected cells. In contrast, mutant clones containing stop codons in either ORF decreased virus infectivity. Injection of adult Drosophila flies with virus derived from CrPV clones but not UV-inactivated clones resulted in mortality. Molecular analysis of the CrPV clone revealed a 196-nucleotide duplication within its 5' untranslated region (UTR) that stimulated translation of reporter constructs. In cells infected with the CrPV clone, the duplication inhibited viral infectivity yet did not affect viral translation or RNA accumulation, suggesting an effect on viral packaging or entry. The generation of the CrPV infectious clone provides a powerful tool for investigating the viral life cycle and pathogenesis of dicistroviruses and may further understanding of fundamental host-virus interactions in insect cells. Dicistroviridae, which are RNA viruses that infect arthropods, have served as a model to gain insights into fundamental host-virus interactions in

  7. Quantitative Analysis of Proteome Modulations in Alveolar Epithelial Type II Cells in Response to Pulmonary Aspergillus fumigatus Infection.

    Science.gov (United States)

    Seddigh, Pegah; Bracht, Thilo; Molinier-Frenkel, Válerie; Castellano, Flavia; Kniemeyer, Olaf; Schuster, Marc; Weski, Juliane; Hasenberg, Anja; Kraus, Andreas; Poschet, Gernot; Hager, Thomas; Theegarten, Dirk; Opitz, Christiane A; Brakhage, Axel A; Sitek, Barbara; Hasenberg, Mike; Gunzer, Matthias

    2017-12-01

    The ubiquitous mold Aspergillus fumigatus threatens immunosuppressed patients as inducer of lethal invasive aspergillosis. A. fumigatus conidia are airborne and reach the alveoli, where they encounter alveolar epithelial cells (AEC). Previous studies reported the importance of the surfactant-producing AEC II during A. fumigatus infection via in vitro experiments using cell lines. We established a negative isolation protocol yielding untouched primary murine AEC II with a purity >90%, allowing ex vivo analyses of the cells, which encountered the mold in vivo By label-free proteome analysis of AEC II isolated from mice 24h after A. fumigatus or mock infection we quantified 2256 proteins and found 154 proteins to be significantly differentially abundant between both groups (ANOVA p value ≤ 0.01, ratio of means ≥1.5 or ≤0.67, quantified with ≥2 peptides). Most of these proteins were higher abundant in the infected condition and reflected a comprehensive activation of AEC II on interaction with A. fumigatus This was especially represented by proteins related to oxidative phosphorylation, hence energy production. However, the most strongly induced protein was the l-amino acid oxidase (LAAO) Interleukin 4 induced 1 (IL4I1) with a 42.9 fold higher abundance (ANOVA p value 2.91 -10 ). IL4I1 has previously been found in B cells, macrophages, dendritic cells and rare neurons. Increased IL4I1 abundance in AEC II was confirmed by qPCR, Western blot and immunohistology. Furthermore, A. fumigatus infected lungs showed high levels of IL4I1 metabolic products. Importantly, higher IL4I1 abundance was also confirmed in lung tissue from human aspergilloma. Because LAAO are key enzymes for bactericidal product generation, AEC II might actively participate in pathogen defense. We provide insights into proteome changes of primary AEC II thereby opening new avenues to analyze the molecular changes of this central lung cell on infectious threats. Data are available via Proteome

  8. Pretreatment with Cry1Ac Protoxin Modulates the Immune Response, and Increases the Survival of Plasmodium-Infected CBA/Ca Mice

    Directory of Open Access Journals (Sweden)

    Martha Legorreta-Herrera

    2010-01-01

    Full Text Available Malaria is a major global health problem that kills 1-2 million people each year. Despite exhaustive research, naturally acquired immunity is poorly understood. Cry1A proteins are potent immunogens with adjuvant properties and are able to induce strong cellular and humoral responses. In fact, it has been shown that administration of Cry1Ac protoxin alone or with amoebic lysates induces protection against the lethal infection caused by the protozoa Naegleria fowleri. In this work, we studied whether Cry1Ac is able to activate the innate immune response to induce protection against Plasmodium berghei ANKA (lethal and P. chabaudi AS (nonlethal parasites in CBA/Ca mice. Treatment with Cry1Ac induced protection against both Plasmodium species in terms of reduced parasitaemia, longer survival time, modulation of pro- and anti-inflammatory cytokines, and increased levels of specific antibodies against Plasmodium. Understanding how to boost innate immunity to Plasmodium infection should lead to immunologically based intervention strategies.

  9. Playing Hide and Seek: How Glycosylation of the Influenza Virus Hemagglutinin Can Modulate the Immune Response to Infection

    Directory of Open Access Journals (Sweden)

    Michelle D. Tate

    2014-03-01

    Full Text Available Seasonal influenza A viruses (IAV originate from pandemic IAV and have undergone changes in antigenic structure, including addition of glycans to the hemagglutinin (HA glycoprotein. The viral HA is the major target recognized by neutralizing antibodies and glycans have been proposed to shield antigenic sites on HA, thereby promoting virus survival in the face of widespread vaccination and/or infection. However, addition of glycans can also interfere with the receptor binding properties of HA and this must be compensated for by additional mutations, creating a fitness barrier to accumulation of glycosylation sites. In addition, glycans on HA are also recognized by phylogenetically ancient lectins of the innate immune system and the benefit provided by evasion of humoral immunity is balanced by attenuation of infection. Therefore, a fine balance must exist regarding the optimal pattern of HA glycosylation to offset competing pressures associated with recognition by innate defenses, evasion of humoral immunity and maintenance of virus fitness. In this review, we examine HA glycosylation patterns of IAV associated with pandemic and seasonal influenza and discuss recent advancements in our understanding of interactions between IAV glycans and components of innate and adaptive immunity.

  10. Playing Hide and Seek: How Glycosylation of the Influenza Virus Hemagglutinin Can Modulate the Immune Response to Infection

    Science.gov (United States)

    Tate, Michelle D.; Job, Emma R.; Deng, Yi-Mo; Gunalan, Vithiagaran; Maurer-Stroh, Sebastian; Reading, Patrick C.

    2014-01-01

    Seasonal influenza A viruses (IAV) originate from pandemic IAV and have undergone changes in antigenic structure, including addition of glycans to the hemagglutinin (HA) glycoprotein. The viral HA is the major target recognized by neutralizing antibodies and glycans have been proposed to shield antigenic sites on HA, thereby promoting virus survival in the face of widespread vaccination and/or infection. However, addition of glycans can also interfere with the receptor binding properties of HA and this must be compensated for by additional mutations, creating a fitness barrier to accumulation of glycosylation sites. In addition, glycans on HA are also recognized by phylogenetically ancient lectins of the innate immune system and the benefit provided by evasion of humoral immunity is balanced by attenuation of infection. Therefore, a fine balance must exist regarding the optimal pattern of HA glycosylation to offset competing pressures associated with recognition by innate defenses, evasion of humoral immunity and maintenance of virus fitness. In this review, we examine HA glycosylation patterns of IAV associated with pandemic and seasonal influenza and discuss recent advancements in our understanding of interactions between IAV glycans and components of innate and adaptive immunity. PMID:24638204

  11. The alkaloid compound harmane increases the lifespan of Caenorhabditis elegans during bacterial infection, by modulating the nematode's innate immune response.

    Directory of Open Access Journals (Sweden)

    Henrik Jakobsen

    Full Text Available The nematode Caenorhabditis elegans has in recent years been proven to be a powerful in vivo model for testing antimicrobial compounds. We report here that the alkaloid compound Harmane (2-methyl-β-carboline increases the lifespan of nematodes infected with a human pathogen, the Shiga toxin-producing Escherichia coli O157:H7 strain EDL933 and several other bacterial pathogens. This was shown to be unrelated to the weak antibiotic effect of Harmane. Using GFP-expressing E. coli EDL933, we showed that Harmane does not lower the colonization burden in the nematodes. We also found that the expression of the putative immune effector gene F35E12.5 was up-regulated in response to Harmane treatment. This indicates that Harmane stimulates the innate immune response of the nematode; thereby increasing its lifespan during bacterial infection. Expression of F35E12.5 is predominantly regulated through the p38 MAPK pathway; however, intriguingly the lifespan extension resulting from Harmane was higher in p38 MAPK-deficient nematodes. This indicates that Harmane has a complex effect on the innate immune system of C. elegans. Harmane could therefore be a useful tool in the further research into C. elegans immunity. Since the innate immunity of C. elegans has a high degree of evolutionary conservation, drugs such as Harmane could also be possible alternatives to classic antibiotics. The C. elegans model could prove to be useful for selection and development of such drugs.

  12. The alkaloid compound harmane increases the lifespan of Caenorhabditis elegans during bacterial infection, by modulating the nematode's innate immune response.

    Science.gov (United States)

    Jakobsen, Henrik; Bojer, Martin S; Marinus, Martin G; Xu, Tao; Struve, Carsten; Krogfelt, Karen A; Løbner-Olesen, Anders

    2013-01-01

    The nematode Caenorhabditis elegans has in recent years been proven to be a powerful in vivo model for testing antimicrobial compounds. We report here that the alkaloid compound Harmane (2-methyl-β-carboline) increases the lifespan of nematodes infected with a human pathogen, the Shiga toxin-producing Escherichia coli O157:H7 strain EDL933 and several other bacterial pathogens. This was shown to be unrelated to the weak antibiotic effect of Harmane. Using GFP-expressing E. coli EDL933, we showed that Harmane does not lower the colonization burden in the nematodes. We also found that the expression of the putative immune effector gene F35E12.5 was up-regulated in response to Harmane treatment. This indicates that Harmane stimulates the innate immune response of the nematode; thereby increasing its lifespan during bacterial infection. Expression of F35E12.5 is predominantly regulated through the p38 MAPK pathway; however, intriguingly the lifespan extension resulting from Harmane was higher in p38 MAPK-deficient nematodes. This indicates that Harmane has a complex effect on the innate immune system of C. elegans. Harmane could therefore be a useful tool in the further research into C. elegans immunity. Since the innate immunity of C. elegans has a high degree of evolutionary conservation, drugs such as Harmane could also be possible alternatives to classic antibiotics. The C. elegans model could prove to be useful for selection and development of such drugs.

  13. The bacteria profiles of wounds in diabetic patients hospitalized in ...

    African Journals Online (AJOL)

    Diabetic wound infections still remain a health concern such that correct identification of bacteria is essential in monitoring the spread of the infections as well as in the administration of the correct treatment. This study therefore focuses on isolating and identifying bacteria present in diabetic wounds of hospitalized patients in ...

  14. A product of heme catabolism modulates bacterial function and survival.

    Directory of Open Access Journals (Sweden)

    Christopher L Nobles

    Full Text Available Bilirubin is the terminal metabolite in heme catabolism in mammals. After deposition into bile, bilirubin is released in large quantities into the mammalian gastrointestinal (GI tract. We hypothesized that intestinal bilirubin may modulate the function of enteric bacteria. To test this hypothesis, we investigated the effect of bilirubin on two enteric pathogens; enterohemorrhagic E. coli (EHEC, a Gram-negative that causes life-threatening intestinal infections, and E. faecalis, a Gram-positive human commensal bacterium known to be an opportunistic pathogen with broad-spectrum antibiotic resistance. We demonstrate that bilirubin can protect EHEC from exogenous and host-generated reactive oxygen species (ROS through the absorption of free radicals. In contrast, E. faecalis was highly susceptible to bilirubin, which causes significant membrane disruption and uncoupling of respiratory metabolism in this bacterium. Interestingly, similar results were observed for other Gram-positive bacteria, including B. cereus and S. aureus. A model is proposed whereby bilirubin places distinct selective pressure on enteric bacteria, with Gram-negative bacteria being protected from ROS (positive outcome and Gram-positive bacteria being susceptible to membrane disruption (negative outcome. This work suggests bilirubin has differential but biologically relevant effects on bacteria and justifies additional efforts to determine the role of this neglected waste catabolite in disease processes, including animal models.

  15. Discovery of Functional Toxin/Antitoxin Systems in Bacteria by Shotgun Cloning

    Energy Technology Data Exchange (ETDEWEB)

    Sberro, Hila; Leavitt, Azita; Kiro, Ruth; Koh, Eugene; Peleg, Yoav; Qimron, Udi; Sorek, Rotem

    2013-04-01

    Toxin-antitoxin (TA) modules, composed of a toxic protein and a counteracting antitoxin, play important roles in bacterial physiology. We examined the experimental insertion of 1.5 million genes from 388 microbial genomes into an Escherichia coli host using over 8.5 million random clones. This revealed hundreds of genes (toxins) that could only be cloned when the neighboring gene (antitoxin) was present on the same clone. Clustering of these genes revealed TA families widespread in bacterial genomes, some of which deviate from the classical characteristics previously described for such modules. Introduction of these genes into E. coli validated that the toxin toxicity is mitigated by the antitoxin. Infection experiments with T7 phage showed that two of the new modules can provide resistance against phage. Moreover, our experiments revealed an 'anti-defense' protein in phage T7 that neutralizes phage resistance. Our results expose active fronts in the arms race between bacteria and phage.

  16. 77 FR 59928 - Draft Guidance for Industry on Complicated Intra-Abdominal Infections: Developing Drugs for...

    Science.gov (United States)

    2012-10-01

    ... bacteria, Gram-positive bacteria, and anaerobic bacteria, and there are also mixed infections. This draft... infection caused by bacterial pathogens that show resistance to most antibacterial drugs on in vitro...

  17. Potential role of bacteria packaging by protozoa in the persistence and transmission of pathogenic bacteria

    Directory of Open Access Journals (Sweden)

    Alix M Denoncourt

    2014-05-01

    Full Text Available Many pathogenic bacteria live in close association with protozoa. These unicellular eukaryotic microorganisms are ubiquitous in various environments. A number of protozoa such as amoebae and ciliates ingest pathogenic bacteria, package them usually in membrane structures, and then release them into the environment. Packaged bacteria are more resistant to various stresses and are more apt to survive than free bacteria. New evidence indicates that protozoa and not bacteria control the packaging process. It is possible that packaging is more common than suspected and may play a major role in the persistence and transmission of pathogenic bacteria. To confirm the role of packaging in the propagation of infections, it is vital that the molecular mechanisms governing the packaging of bacteria by protozoa be identified as well as elements related to the ecology of this process in order to determine whether packaging acts as a Trojan Horse.

  18. The alkaloid compound harmane increases the lifespan of Caenorhabditis elegans during bacterial infection, by modulating the nematode's innate immune response

    DEFF Research Database (Denmark)

    Jakobsen, Henrik; Bojer, Martin Saxtorph; Marinus, Martin G.

    2013-01-01

    pathway; however, intriguingly the lifespan extension resulting from Harmane was higher in p38 MAPK-deficient nematodes. This indicates that Harmane has a complex effect on the innate immune system of C. elegans. Harmane could therefore be a useful tool in the further research into C. elegans immunity....... Since the innate immunity of C. elegans has a high degree of evolutionary conservation, drugs such as Harmane could also be possible alternatives to classic antibiotics. The C. elegans model could prove to be useful for selection and development of such drugs.......The nematode Caenorhabditis elegans has in recent years been proven to be a powerful in vivo model for testing antimicrobial compounds. We report here that the alkaloid compound Harmane (2-methyl-β-carboline) increases the lifespan of nematodes infected with a human pathogen, the Shiga toxin...

  19. Bactericidal effects of antibiotics on slowly growing and nongrowing bacteria.

    OpenAIRE

    Eng, R H; Padberg, F T; Smith, S M; Tan, E N; Cherubin, C E

    1991-01-01

    Antimicrobial agents are most often tested against bacteria in the log phase of multiplication to produce the maximum bactericidal effect. In an infection, bacteria may multiply less optimally. We examined the effects of several classes of antimicrobial agents to determine their actions on gram-positive and gram-negative bacteria during nongrowing and slowly growing phases. Only ciprofloxacin and ofloxacin exhibited bactericidal activity against nongrowing gram-negative bacteria, and no antib...

  20. Urinary Tract Infections (For Kids)

    Medline Plus

    Full Text Available ... Mind Sexual Health Food & Fitness Diseases & Conditions Infections Drugs & Alcohol School & Jobs Sports Expert Answers (Q&A) ... a bladder infection, your doctor will order some medicine for you to take to kill the bacteria. ...

  1. Urinary Tract Infections (For Kids)

    Medline Plus

    Full Text Available ... padres General Health Growth & Development Infections Diseases & Conditions Pregnancy & Baby Nutrition & Fitness Emotions & Behavior School & Family Life ... get up into the bladder more easily and cause an infection there. Some of the bacteria that ...

  2. Human Management of a Wild Plant Modulates the Evolutionary Dynamics of a Gene Determining Recessive Resistance to Virus Infection.

    Science.gov (United States)

    Poulicard, Nils; Pacios, Luis Fernández; Gallois, Jean-Luc; Piñero, Daniel; García-Arenal, Fernando

    2016-08-01

    This work analyses the genetic variation and evolutionary patterns of recessive resistance loci involved in matching-allele (MA) host-pathogen interactions, focusing on the pvr2 resistance gene to potyviruses of the wild pepper Capsicum annuum glabriusculum (chiltepin). Chiltepin grows in a variety of wild habitats in Mexico, and its cultivation in home gardens started about 25 years ago. Potyvirus infection of Capsicum plants requires the physical interaction of the viral VPg with the pvr2 product, the translation initiation factor eIF4E1. Mutations impairing this interaction result in resistance, according to the MA model. The diversity of pvr2/eIF4E1 in wild and cultivated chiltepin populations from six biogeographical provinces in Mexico was analysed in 109 full-length coding sequences from 97 plants. Eleven alleles were found, and their interaction with potyvirus VPg in yeast-two-hybrid assays, plus infection assays of plants, identified six resistance alleles. Mapping resistance mutations on a pvr2/eIF4E1 model structure showed that most were around the cap-binding pocket and strongly altered its surface electrostatic potential, suggesting resistance-associated costs due to functional constraints. The pvr2/eIF4E1 phylogeny established that susceptibility was ancestral and resistance was derived. The spatial structure of pvr2/eIF4E1 diversity differed from that of neutral markers, but no evidence of selection for resistance was found in wild populations. In contrast, the resistance alleles were much more frequent, and positive selection stronger, in cultivated chiltepin populations, where diversification of pvr2/eIF4E1 was higher. This analysis of the genetic variation of a recessive resistance gene involved in MA host-pathogen interactions in populations of a wild plant show that evolutionary patterns differ according to the plant habitat, wild or cultivated. It also demonstrates that human management of the plant population has profound effects on the

  3. Human Management of a Wild Plant Modulates the Evolutionary Dynamics of a Gene Determining Recessive Resistance to Virus Infection.

    Directory of Open Access Journals (Sweden)

    Nils Poulicard

    2016-08-01

    Full Text Available This work analyses the genetic variation and evolutionary patterns of recessive resistance loci involved in matching-allele (MA host-pathogen interactions, focusing on the pvr2 resistance gene to potyviruses of the wild pepper Capsicum annuum glabriusculum (chiltepin. Chiltepin grows in a variety of wild habitats in Mexico, and its cultivation in home gardens started about 25 years ago. Potyvirus infection of Capsicum plants requires the physical interaction of the viral VPg with the pvr2 product, the translation initiation factor eIF4E1. Mutations impairing this interaction result in resistance, according to the MA model. The diversity of pvr2/eIF4E1 in wild and cultivated chiltepin populations from six biogeographical provinces in Mexico was analysed in 109 full-length coding sequences from 97 plants. Eleven alleles were found, and their interaction with potyvirus VPg in yeast-two-hybrid assays, plus infection assays of plants, identified six resistance alleles. Mapping resistance mutations on a pvr2/eIF4E1 model structure showed that most were around the cap-binding pocket and strongly altered its surface electrostatic potential, suggesting resistance-associated costs due to functional constraints. The pvr2/eIF4E1 phylogeny established that susceptibility was ancestral and resistance was derived. The spatial structure of pvr2/eIF4E1 diversity differed from that of neutral markers, but no evidence of selection for resistance was found in wild populations. In contrast, the resistance alleles were much more frequent, and positive selection stronger, in cultivated chiltepin populations, where diversification of pvr2/eIF4E1 was higher. This analysis of the genetic variation of a recessive resistance gene involved in MA host-pathogen interactions in populations of a wild plant show that evolutionary patterns differ according to the plant habitat, wild or cultivated. It also demonstrates that human management of the plant population has profound

  4. Human body may produce bacteria.

    Science.gov (United States)

    Salerian, Alen J

    2017-06-01

    "Human body may produce bacteria" proposes that human body may produce bacteria and represent an independent source of infections contrary to the current paradigm of infectious disorders proposed by Louis Pasteur in 1880. The following observations are consistent with this hypothesis: A. Bidirectional transformations of both living and nonliving things have been commonly observed in nature. B. Complex multicellular organisms harbor the necessary properties to produce bacteria (water, nitrogen and oxygen). C. Physical laws suggest any previously observed phenomenon or action will occur again (life began on earth; a non living thing). D. Animal muscle cells may generate energy (fermentation). E. Sterilized food products (i.e. boiled eggs), may produce bacteria and fungus under special conditions and without any exposure to foreign living cells. "Human body may produce bacteria" may challenge the current medical paradigm that views human infectious disorders as the exclusive causative byproducts of invading foreign cells. It may also introduce new avenues to treat infectious disorders. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Bacterial feeding, Leishmania infection and distinct infection routes induce differential defensin expression in Lutzomyia longipalpis.

    Science.gov (United States)

    Telleria, Erich L; Sant'Anna, Maurício R Viana; Alkurbi, Mohammad O; Pitaluga, André N; Dillon, Rod J; Traub-Csekö, Yara M

    2013-01-11

    Phlebotomine insects harbor bacterial, viral and parasitic pathogens that can cause diseases of public health importance. Lutzomyia longipalpis is the main vector of visceral leishmaniasis in the New World. Insects can mount a powerful innate immune response to pathogens. Defensin peptides take part in this response and are known to be active against Gram-positive and Gram-negative bacteria, and some parasites. We studied the expression of a defensin gene from Lutzomyia longipalpis to understand its role in sand fly immune response. We identified, sequenced and evaluated the expression of a L. longipalpis defensin gene by semi-quantitative RT-PCR. The gene sequence was compared to other vectors defensins and expression was determined along developmental stages and after exposure of adult female L. longipalpis to bacteria and Leishmania. Phylogenetic analysis showed that the L. longipalpis defensin is closely related to a defensin from the Old World sand fly Phlebotomus duboscqi. Expression was high in late L4 larvae and pupae in comparison to early larval stages and newly emerged flies. Defensin expression was modulated by oral infection with bacteria. The Gram-positive Micrococcus luteus induced early high defensin expression, whilst the Gram-negative entomopathogenic Serratia marcescens induced a later response. Bacterial injection also induced defensin expression in adult insects. Female sand flies infected orally with Leishmania mexicana showed no significant difference in defensin expression compared to blood fed insects apart from a lower defensin expression 5 days post Leishmania infection. When Leishmania was introduced into the hemolymph by injection there was no induction of defensin expression until 72 h later. Our results suggest that L. longipalpis modulates defensin expression upon bacterial and Leishmania infection, with patterns of expression that are distinct among bacterial species and routes of infection.

  6. Modulation of Quorum Sensing in a Gram-Positive Pathogen by Linear Molecularly Imprinted Polymers with Anti-infective Properties.

    Science.gov (United States)

    Motib, Anfal; Guerreiro, Antonio; Al-Bayati, Firas; Piletska, Elena; Manzoor, Irfan; Shafeeq, Sulman; Kadam, Anagha; Kuipers, Oscar; Hiller, Luisa; Cowen, Todd; Piletsky, Sergey; Andrew, Peter W; Yesilkaya, Hasan

    2017-12-22

    We describe the development, characterization, and biological testing of a new type of linear molecularly imprinted polymer (LMIP) designed to act as an anti-infective by blocking the quorum sensing (QS) mechanism and so abrogating the virulence of the pathogen Streptococcus pneumoniae. The LMIP is prepared (polymerized) in presence of a template molecule, but unlike in traditional molecular imprinting approaches, no cross-linker is used. This results in soluble low-molecular-weight oligomers that can act as a therapeutic agent in vitro and in vivo. The LMIP was characterized by mass spectrometry to determine its monomer composition. Fragments identified were then aligned along the peptide template by computer modeling to predict the possible monomer sequence of the LMIP. These findings provide a proof of principle that LMIPs can be used to block QS, thus setting the stage for the development of LMIPs a novel drug-discovery platform and class of materials to target Gram-positive pathogens. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Assessment of the bacteria reduction in the infected root canal irradiated with diode laser; Avaliacao da reducao bacteriana em conduto radicular infectado e irradiado com laser de diodo. Estudo in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Radaelli, Claudia Amaral Rabello de Mello

    2002-07-01

    High success rates are achieved in conventional endodontic treatment of vital pulp teeth. However, in cases of non-vital pulp, a decrease in the rate of success occurs due to difficulties in achieving a complete disinfection of the root canals system. Some bacteria, such as Enterococcus faecalis, are frequently found in cases of endodontic treatment failure due to their high resistance to the conventional endodontic treatment. The aim of this study was to evaluate the efficiency of a high power diode laser irradiation in bacterial reduction of contaminated canals associated with dressing compose by calcium hydroxide paste propylene glycol and camphorated paramonochlorophenol. Eighty-two root canals were infected in vitro with Enterococcus faecalis in a concentration of 1x10{sup 8} CFU/ml. Specimens were high intensity irradiated with a diode laser model Opus 10, at a wavelength of 830 nm. Two different parameters were employed in continuous mode: 3 W and 2,5 W with a 360 {mu}m optical fiber at an angle of approximately 5 degrees respect to the dentine surface during 5 seconds, in 4 applications, with 20 seconds intervals among them. After these proceedings specimens were vortexed in peptone water and dilutions performed. Aliquots of the dilution were plated on m-Enterococcus agar, incubated, and the Colonies Forming Units (CFU) of ali groups was counted. The results showed a significant reduction of bacteria on ali groups after laser irradiation. A high reduction rate was achieved: 98.5% immediately after the laser irradiation; 48 hours after, the reduction was of 96,73% and, finally, a 100% reduction was achieved through the combination of laser irradiation and a long lasting dressing of calcium hydroxide paste, propylene glycol and camphorated paramonochlorophenol. High rates of bacteria reduction were achieved using the parameter of 3 W in continuous mode with the power of 2,9473 KW/cm{sup 2}. The temperature was monitored with a K-pipe thermocouple placed at

  8. Adipose Tissue-Derived Mesenchymal Stromal Cells Protect Mice Infected with Trypanosoma cruzi from Cardiac Damage through Modulation of Anti-parasite Immunity.

    Science.gov (United States)

    Mello, Debora B; Ramos, Isalira P; Mesquita, Fernanda C P; Brasil, Guilherme V; Rocha, Nazareth N; Takiya, Christina M; Lima, Ana Paula C A; Campos de Carvalho, Antonio C; Goldenberg, Regina S; Carvalho, Adriana B

    2015-01-01

    Chagas disease, caused by the protozoan Trypanosoma cruzi (T. cruzi), is a complex disease endemic in Central and South America. It has been gathering interest due to increases in non-vectorial forms of transmission, especially in developed countries. The objective of this work was to investigate if adipose tissue-derived mesenchymal stromal cells (ASC) can alter the course of the disease and attenuate pathology in a mouse model of chagasic cardiomyopathy. ASC were injected intraperitoneally at 3 days post-infection (dpi). Tracking by bioluminescence showed that cells remained in the abdominal cavity for up to 9 days after injection and most of them migrated to the abdominal or subcutaneous fat, an early parasite reservoir. ASC injection resulted in a significant reduction in blood parasitemia, which was followed by a decrease in cardiac tissue inflammation, parasitism and fibrosis at 30 dpi. At the same time point, analyses of cytokine release in cells isolated from the heart and exposed to T. cruzi antigens indicated an anti-inflammatory response in ASC-treated animals. In parallel, splenocytes exposed to the same antigens produced a pro-inflammatory response, which is important for the control of parasite replication, in placebo and ASC-treated groups. However, splenocytes from the ASC group released higher levels of IL-10. At 60 dpi, magnetic resonance imaging revealed that right ventricular (RV) dilation was prevented in ASC-treated mice. In conclusion, the injection of ASC early after T. cruzi infection prevents RV remodeling through the modulation of immune responses. Lymphoid organ response to the parasite promoted the control of parasite burden, while the heart, a target organ of Chagas disease, was protected from damage due to an improved control of inflammation in ASC-treated mice.

  9. Adipose Tissue-Derived Mesenchymal Stromal Cells Protect Mice Infected with Trypanosoma cruzi from Cardiac Damage through Modulation of Anti-parasite Immunity.

    Directory of Open Access Journals (Sweden)

    Debora B Mello

    Full Text Available Chagas disease, caused by the protozoan Trypanosoma cruzi (T. cruzi, is a complex disease endemic in Central and South America. It has been gathering interest due to increases in non-vectorial forms of transmission, especially in developed countries. The objective of this work was to investigate if adipose tissue-derived mesenchymal stromal cells (ASC can alter the course of the disease and attenuate pathology in a mouse model of chagasic cardiomyopathy.ASC were injected intraperitoneally at 3 days post-infection (dpi. Tracking by bioluminescence showed that cells remained in the abdominal cavity for up to 9 days after injection and most of them migrated to the abdominal or subcutaneous fat, an early parasite reservoir. ASC injection resulted in a significant reduction in blood parasitemia, which was followed by a decrease in cardiac tissue inflammation, parasitism and fibrosis at 30 dpi. At the same time point, analyses of cytokine release in cells isolated from the heart and exposed to T. cruzi antigens indicated an anti-inflammatory response in ASC-treated animals. In parallel, splenocytes exposed to the same antigens produced a pro-inflammatory response, which is important for the control of parasite replication, in placebo and ASC-treated groups. However, splenocytes from the ASC group released higher levels of IL-10. At 60 dpi, magnetic resonance imaging revealed that right ventricular (RV dilation was prevented in ASC-treated mice.In conclusion, the injection of ASC early after T. cruzi infection prevents RV remodeling through the modulation of immune responses. Lymphoid organ response to the parasite promoted the control of parasite burden, while the heart, a target organ of Chagas disease, was protected from damage due to an improved control of inflammation in ASC-treated mice.

  10. AIDS: "it's the bacteria, stupid!".

    Science.gov (United States)

    Broxmeyer, Lawrence; Cantwell, Alan

    2008-11-01

    Acid-fast tuberculous mycobacterial infections are common in AIDS and are regarded as secondary "opportunistic infections." According to the National Institute of Allergy and Infectious Diseases, TB is the major attributable cause of death in AIDS patients. Could such bacteria play a primary or causative role in AIDS? Certainly, In screening tests for HIV, there is frequent, up to 70%, cross-reactivity, between the gag and pol proteins of HIV and patients with mycobacterial infections such as tuberculosis. By 1972, five years before gays started dying in the U.S., Rolland wrote Genital Tuberculosis, a Forgotten Disease? And ironically, in 1979, on the eve of AIDS recognition, Gondzik and Jasiewicz showed that even in the laboratory, genitally infected tubercular male guinea pigs could infect healthy females through their semen by an HIV-compatible ratio of 1 in 6 or 17%, prompting him to warn his patients that not only was tuberculosis a sexually transmitted disease, but also the necessity of the application of suitable contraceptives, such as condoms, to avoid it. Gondzik's solution and date of publication are chilling; his findings significant. Since 1982 Cantwell et al found acid-fast bacteria closely related to tuberculosis (TB) and atypical tuberculosis in AIDS tissue. On the other hand molecular biologist and virologist Duesberg, who originally defined retroviral ultrastructure, has made it clear that HIV is not the cause of AIDS and that the so-called AIDS retrovirus has never been isolated in its pure state. Dr. Etienne de Harven, first to examine retroviruses under the electron, agrees. In 1993 HIV co-discoverer Luc Montagnier reported on cell-wall-deficient (CWD) bacteria which he called "mycoplasma" in AIDS tissue. He suspected these as a necessary "co-factor" for AIDS. Remarkably, Montagnier remained silent on Cantwell's reports of acid-fast bacteria which could simulate "mycoplasma" in AIDS tissue. Mattman makes clear that the differentiation between

  11. Beneficial Effect of Bidens pilosa on Body Weight Gain, Food Conversion Ratio, Gut Bacteria and Coccidiosis in Chickens.

    Directory of Open Access Journals (Sweden)

    Cicero L T Chang

    Full Text Available In the interests of food safety and public health, plants and their compounds are now re-emerging as an alternative approach to treat gastrointestinal diseases in chickens. Here, we studied the impact of the edible medicinal plant, B. pilosa, on growth performance, gut bacteria and coccidiosis in chickens. First, we found that B. pilosa significantly elevated body weight gain and lowered feed conversion ratio in chickens. Next, we showed that B. pilosa reduced cecal damage as evidenced by increased hemorrhage, villus destruction and decreased villus-to-crypt ratio in chicken ceca. We also performed pyrosequencing of the PCR ampilcons based on the 16S rRNA genes of gut bacteria in chickens. Metagenomic analysis indicated that the chicken gut bacteria belonged to 6 phyla, 6 classes, 6 orders, 9 families, and 8 genera. More importantly, we found that B. pilosa affected the composition of bacteria. This change in bacteria composition was correlated with body weight gain, feed conversion ratio and gut pathology in chickens. Collectively, this work suggests that B. pilosa has beneficial effects on growth performance and protozoan infection in chickens probably via modulation of gut bacteria.

  12. Helicobacter pylori infection

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007715.htm Helicobacter pylori infection To use the sharing features on this page, please enable JavaScript. Helicobacter pylori ( H pylori ) is a type of bacteria that ...

  13. Ear Infections in Children

    Science.gov (United States)

    ... ear infections may get better without antibiotics. Using antibiotics cautiously and with good reason helps prevent the development of bacteria that become resistant to antibiotics. If your doctor prescribes an antibiotic, it’s important ...

  14. Infection of Human Fallopian Tube Epithelial Cells with Neisseria gonorrhoeae Protects Cells from Tumor Necrosis Factor Alpha-Induced Apoptosis

    Science.gov (United States)

    Morales, Priscilla; Reyes, Paz; Vargas, Macarena; Rios, Miguel; Imarai, Mónica; Cardenas, Hugo; Croxatto, Horacio; Orihuela, Pedro; Vargas, Renato; Fuhrer, Juan; Heckels, John E.; Christodoulides, Myron; Velasquez, Luis

    2006-01-01

    Following infection with Neisseria gonorrhoeae, bacteria may ascend into the Fallopian tubes (FT) and induce salpingitis, a major cause of infertility. In the FT, interactions between mucosal epithelial cells and gonococci are pivotal events in the pathogen's infection cycle and the inflammatory response. In the current study, primary FT epithelial cells were infected in vitro with different multiplicities of infection (MOI) of Pil+ Opa+ gonococci. Bacteria showed a dose-dependent association with cells and induced the secretion of tumor necrosis factor alpha (TNF-α). A significant finding was that gonococcal infection (MOI = 1) induced apoptosis in approximately 30% of cells, whereas increasing numbers of bacteria (MOI = 10 to 100) did not induce apoptosis. Apoptosis was observed in only 11% of cells with associated bacteria, whereas >84% of cells with no adherent bacteria were apoptotic. TNF-α was a key contributor to apoptosis, since (i) culture supernatants from cells infected with gonococci (MOI = 1) induced apoptosis in naïve cultures, suggesting that a soluble factor was responsible; (ii) gonococcal infection-induced apoptosis was inhibited with anti-TNF-α antibodies; and (iii) the addition of exogenous TNF-α induced apoptosis, which was inhibited by the presence of increasing numbers of bacteria (MOI = 10 to 100). These data suggest that TNF-α-mediated apoptosis of FT epithelial cells is likely a primary host defense mechanism to prevent pathogen colonization. However, epithelial cell-associated gonococci have evolved a mechanism to protect the cells from undergoing TNF-α-mediated apoptosis, and this modulation of the host innate response may contribute to establishment of infection. Understanding the antiapoptotic mechanisms used by Neisseria gonorrhoeae will inform the pathogenesis of salpingitis and could suggest new intervention strategies for prevention and treatment of the disease. PMID:16714596

  15. Biofilm Infections

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Jensen, Peter Østrup; Moser, Claus Ernst

    A still increasing interest and emphasis on the sessile bacterial lifestyle biofilms has been seen since it was realized that the vast majority of the total microbial biomass exists as biofilms. Aggregation of bacteria was first described by Leeuwenhoek in 1677, but only recently recognized...... as being important in chronic infection. In 1993 the American Society for Microbiology (ASM) recognized that the biofilm mode of growth was relevant to microbiology. This book covers both the evidence for biofilms in many chronic bacterial infections as well as the problems facing these infections...... such as diagnostics, pathogenesis, treatment regimes and in vitro and in vivo models for studying biofilms. This is the first scientific book on biofilm infections, chapters written by the world leading scientist and clinicians. The intended audience of this book is scientists, teachers at university level as well...

  16. Insights into the Impact of CD8+ Immune Modulation on Human Immunodeficiency Virus Evolutionary Dynamics in Distinct Anatomical Compartments by Using Simian Immunodeficiency Virus-Infected Macaque Models of AIDS Progression.

    Science.gov (United States)

    Rife Magalis, Brittany; Nolan, David J; Autissier, Patrick; Burdo, Tricia H; Williams, Kenneth C; Salemi, Marco

    2017-12-01

    A thorough understanding of the role of human immunodeficiency virus (HIV) intrahost evolution in AIDS pathogenesis has been limited by the need for longitudinally sampled viral sequences from the vast target space within the host, which are often difficult to obtain from human subjects. CD8 + lymphocyte-depleted macaques infected with simian immunodeficiency virus (SIV) provide an increasingly utilized model of pathogenesis due to clinical manifestations similar to those for HIV-1 infection and AIDS progression, as well as a characteristic rapid disease onset. Comparison of this model with SIV-infected non-CD8 + lymphocyte-depleted macaques also provides a unique opportunity to investigate the role of CD8 + cells in viral evolution and population dynamics throughout the duration of infection. Using several different phylogenetic methods, we analyzed viral gp120 sequences obtained from extensive longitudinal sampling of multiple tissues and enriched leukocyte populations from SIVmac251-infected macaques with or without CD8 + lymphocyte depletion. SIV evolutionary and selection patterns in non-CD8 + lymphocyte-depleted animals were characterized by sequential population turnover and continual viral adaptation, a scenario readily comparable to intrahost evolutionary patterns during human HIV infection in the absence of antiretroviral therapy. Alternatively, animals that were depleted of CD8 + lymphocytes exhibited greater variation in population dynamics among tissues and cell populations over the course of infection. Our findings highlight the major role for CD8 + lymphocytes in prolonging disease progression through continual control of SIV subpopulations from various anatomical compartments and the potential for greater independent viral evolutionary behavior among these compartments in response to immune modulation. IMPORTANCE Although developments in combined antiretroviral therapy (cART) strategies have successfully prolonged the time to AIDS onset in HIV-1

  17. Ascaris suum infection negatively affects the response to a Mycoplasma hyopneumoniae vaccination and subsequent challenge infection in pigs

    DEFF Research Database (Denmark)

    Steenhard, Nina R.; Jungersen, Gregers; Kokotovic, Branko

    2009-01-01

    Since their first introduction more than a century ago, vaccines have become one of the most cost-effective tools to prevent and manage infectious diseases in human and animal populations. It is vital to understand the possible mechanisms that may impair optimal vaccine efficacy. The hypothesis...... posed in this study was that a concurrent Ascaris suum infection of pigs vaccinated with a Mycoplasma hyopneumoniae (Mh)vaccine would modulate the protectiveimmuneresponse to a subsequent challenge infection. Four groups of pigs were either (1) untreated (group C), (2) vaccinated againstMh 3 weeks after...... the start of the study (group V), (3) given a trickle infection with A. suum throughout the study (group A), or (4) given a trickle infection with A. suum and vaccinated against Mh (group AV). All pigs were subsequently inoculated with live Mh bacteria 4 weeks after the Mh vaccination and necropsied after...

  18. Isolamento e teste de susceptibilidade a antimicrobianos de bactérias em infecções uterinas de éguas Isolation and antimicrobial susceptibility of bacteria in uterine infections in mares

    Directory of Open Access Journals (Sweden)

    N. Silva

    1999-06-01

    Full Text Available Foram examinados 206 "swabs" cervicais e uterinos de éguas de várias raças, de diversas regiões do Estado de Minas Gerais, durante o período de 1986 a 1996. Cerca de 164 "swabs" foram positivos para a presença de microrganismos causadores de endometrites. Streptococcus equi subsp. zooepidemicus (25,7% e Escherichia coli (15,1% foram os principais agentes infecciosos isolados. Outros microrganismos presentes foram: Staphylococcus aureus (9,2%, Streptococcus alfa-hemolítico (9,2%, Pseudomonas aeruginosa (3,9%, Staphylococcus coagulase negativo (6,3%, Bacillus spp. (1,9%, Rhodococcus equi (3,4% e Proteus mirabilis (1,5%. As provas de susceptibilidade aos antimicrobianos revelaram que amicacina e gentamicina (70,2%, ampicilina (59,5% e cloranfenicol (59,5% foram os antibióticos de maior ação in vitro contra os microrganismos isolados.This study examined 206 cervical and uterine swabs collected from infected mares from herds in the Minas Gerais State, Brazil, from 1986 to 1996. Amongst 164 successful isolations, 25.7% were identified as Streptococcus equi, subsp. zooepidemicus, and 15.1% as Escherichia coli, both considered the most important isolates. Other bacteria found included Staphylococcus aureus (9.2%, Streptococcus alpha-hemolytic (9.2%, Pseudomonas aeruginosa (3.9%, coagulase negative Staphylococcus (6.3%, Bacillus spp. (1.9%, Rhodococcus equi (3.4% and Proteus mirabilis (1.5%. The antibiotic susceptibility tests revealed amikacin and gentamicin (70.2%, ampicillin and chloramphenicol (59.5% as the most effective in vitro antibiotics against these microorganisms.

  19. Effects of Methicillin-Resistant Staphylococcus aureus/Multiresistant Gram-Negative Bacteria Colonization or Infection and Isolation Measures in End of Life on Family Caregivers: Results of a Qualitative Study.

    Science.gov (United States)

    Heckel, Maria; Sturm, Alexander; Herbst, Franziska A; Ostgathe, Christoph; Stiel, Stephanie

    2017-03-01

    Little is known about the experiences of family caregivers of hospitalized patients with confirmed methicillin-resistant Staphylococcus aureus/multiresistant gram-negative bacteria (MRSA/MRGN) diagnosis at the end of life. The study at hand is a subproject of an interdisciplinary cooperation project that aims at developing a patient-, family-, and team-centered approach in dealing with MRSA/MRGN-positive hospitalized patients in palliative and geriatric care. The present study aimed to assess the individual effects of the patient's MRSA/MRGN colonization or infection and isolation measures on family caregivers. Between April 2014 and September 2015, all known family caregivers associated with an MRSA/MRGN-positive patient from a palliative care unit, a hospital palliative care support team, and a geriatric ward were considered for study participation. A qualitative interview study with family caregivers and an additional focus group was conducted. Data were analyzed using the principles of Grounded Theory. Family caregivers (N = 62) raised suggestions regarding the provision of information and communication on the MRSA/MRGN diagnosis and hygiene measures from staff members and the consistency of hygiene procedures. Family caregivers requested not to be stigmatized or being disadvantaged due to the MRSA/MRGN diagnosis of the patient, and they wished to receive psychosocial and emotional support. Staff members and institutional stakeholders should be aware that family caregivers might be burdened and upset by positive MRSA/MRGN diagnosis and the required hygiene measures. The need for detailed and understandable information on MRSA/MRGN, adequate communication between staff members and family caregivers, and support for family caregivers should be of special attention in particular in end-of-life care.

  20. Bleach vs. Bacteria

    Science.gov (United States)

    ... Articles | Inside Life Science Home Page Bleach vs. Bacteria By Sharon Reynolds Posted April 2, 2014 Your ... hypochlorous acid to help kill invading microbes, including bacteria. Researchers funded by the National Institutes of Health ...

  1. Bactericidal effectiveness of modulated UV light

    International Nuclear Information System (INIS)

    Bank, H.L.; John, J.; Schmehl, M.K.; Dratch, R.J.

    1990-01-01

    Studies were designed to evaluate the effectiveness of pulsed modulated UV light waveforms for killing bacteria. Exposure of five strains of bacteria to the modulated information encoded in the light decreased the colony population from a confluent lawn to less than 20 colonies. However, approximately 2,000 colonies survived treatment with the same intensity and time of exposure to UV light lacking the modulated information

  2. Bacteria and lignin degradation

    Institute of Scientific and Technical Information of China (English)

    Jing LI; Hongli YUAN; Jinshui YANG

    2009-01-01

    Lignin is both the most abundant aromatic (phenolic) polymer and the second most abundant raw material.It is degraded and modified by bacteria in the natural world,and bacteria seem to play a leading role in decomposing lignin in aquatic ecosystems.Lignin-degrading bacteria approach the polymer by mechanisms such as tunneling,erosion,and cavitation.With the advantages of immense environmental adaptability and biochemical versatility,bacteria deserve to be studied for their ligninolytic potential.

  3. Immunobiotic Bifidobacteria Strains Modulate Rotavirus Immune Response in Porcine Intestinal Epitheliocytes via Pattern Recognition Receptor Signaling.

    Directory of Open Access Journals (Sweden)

    Takamasa Ishizuka

    Full Text Available In this work, we aimed to characterize the antiviral response of an originally established porcine intestinal epithelial cell line (PIE cells by evaluating the molecular innate immune response to rotavirus (RVs. In addition, we aimed to select immunomodulatory bacteria with antiviral capabilities. PIE cells were inoculated with RVs isolated from different host species and the infective titers and the molecular innate immune response were evaluated. In addition, the protection against RVs infection and the modulation of immune response by different lactic acid bacteria (LAB strains was studied. The RVs strains OSU (porcine and UK (bovine effectively infected PIE cells. Our results also showed that RVs infection in PIE cells triggered TLR3-, RIG-I- and MDA-5-mediated immune responses with activation of IRF3 and NF-κB, induction of IFN-β and up-regulation of the interferon stimulated genes MxA and RNase L. Among the LAB strains tested, Bifidobacterium infantis MCC12 and B. breve MCC1274 significantly reduced RVs titers in infected PIE cells. The beneficial effects of both bifidobacteria were associated with reduction of A20 expression, and improvements of IRF-3 activation, IFN-β production, and MxA and RNase L expressions. These results indicate the value of PIE cells for studying RVs molecular innate immune response in pigs and for the selection of beneficial bacteria with antiviral capabilities.

  4. Co-Infection of Mosquitoes with Chikungunya and Dengue Viruses Reveals Modulation of the Replication of Both Viruses in Midguts and Salivary Glands of Aedes aegypti Mosquitoes.

    Science.gov (United States)

    Le Coupanec, Alain; Tchankouo-Nguetcheu, Stéphane; Roux, Pascal; Khun, Huot; Huerre, Michel; Morales-Vargas, Ronald; Enguehard, Margot; Lavillette, Dimitri; Missé, Dorothée; Choumet, Valérie

    2017-08-04

    Arthropod-borne virus (arbovirus) infections cause several emerging and resurgent infectious diseases in humans and animals. Chikungunya-affected areas often overlap with dengue-endemic areas. Concurrent dengue virus (DENV) and chikungunya virus (CHIKV) infections have been detected in travelers returning from regions of endemicity. CHIKV and DENV co-infected Aedes albopictus have also been collected in the vicinity of co-infected human cases, emphasizing the need to study co-infections in mosquitoes. We thus aimed to study the pathogen-pathogen interaction involved in these co-infections in DENV/CHIKV co-infected Aedes aegypti mosquitoes. In mono-infections, we detected CHIKV antigens as early as 4 days post-virus exposure in both the midgut (MG) and salivary gland (SG), whereas we detected DENV serotype 2 (DENV-2) antigens from day 5 post-virus exposure in MG and day 10 post-virus exposure in SG. Identical infection rates were observed for singly and co-infected mosquitoes, and facilitation of the replication of both viruses at various times post-viral exposure. We observed a higher replication for DENV-2 in SG of co-infected mosquitoes. We showed that mixed CHIKV and DENV infection facilitated viral replication in Ae. aegypti . The outcome of these mixed infections must be further studied to increase our understanding of pathogen-pathogen interactions in host cells.

  5. Infection control in Indonesian Hospitals

    OpenAIRE

    Duerink, Daphne Offra

    2009-01-01

    The studies in this thesis were performed as part of the AMRIN (Antimicrobial Resistance in Indonesia) study that addressed antimicrobial resistance, antibiotic usage and infection control in Indonesia. They are the first studies that give insight into the incidence of healthcare-associated infections, determinants for carriage of resistant bacteria in Indonesian individuals and the implementation of measures for the prevention of the spread of bacteria and nosocomial infections in Indonesian...

  6. Getting “Inside” Type I IFNs: Type I IFNs in Intracellular Bacterial Infections

    Directory of Open Access Journals (Sweden)

    Deann T. Snyder

    2017-01-01

    Full Text Available Type I interferons represent a unique and complex group of cytokines, serving many purposes during innate and adaptive immunity. Discovered in the context of viral infections, type I IFNs are now known to have myriad effects in infectious and autoimmune disease settings. Type I IFN signaling during bacterial infections is dependent on many factors including whether the infecting bacterium is intracellular or extracellular, as different signaling pathways are activated. As such, the repercussions of type I IFN induction can positively or negatively impact the disease outcome. This review focuses on type I IFN induction and downstream consequences during infection with the following intracellular bacteria: Chlamydia trachomatis, Listeria monocytogenes, Mycobacterium tuberculosis, Salmonella enterica serovar Typhimurium, Francisella tularensis, Brucella abortus, Legionella pneumophila, and Coxiella burnetii. Intracellular bacterial infections are unique because the bacteria must avoid, circumvent, and even co-opt microbial “sensing” mechanisms in order to reside and replicate within a host cell. Furthermore, life inside a host cell makes intracellular bacteria more difficult to target with antibiotics. Because type I IFNs are important immune effectors, modulating this pathway may improve disease outcomes. But first, it is critical to understand the context-dependent effects of the type I IFN pathway in intracellular bacterial infections.

  7. Effect of leukocyte hydrolases on bacteria

    International Nuclear Information System (INIS)

    Cohen, D.; Michel, J.; Ferne, M.; Bergner-Rabinowitz, S.; Ginsburg, I.

    1979-01-01

    Leukocyte extracts, trypsin, and lysozyme are all capable of releasing the bul