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Sample records for aureus bacteremia role

  1. Mild Staphylococcus aureus skin infection improves the course of subsequent endogenous S. aureus bacteremia in mice

    NARCIS (Netherlands)

    S. van den Berg (Sanne); C.P. de Vogel (Corné); A.F. van Belkum (Alex); I.A.J.M. Bakker-Woudenberg (Irma)

    2015-01-01

    textabstractStaphylococcus aureus carriers with S. aureus bacteremia may have a reduced mortality risk compared to non-carriers. A role for the immune system is suggested. Here, we study in mice the effect of mild S. aureus skin infection prior to endogenous or exogenous S. aureus bacteremia, and ev

  2. Mild Staphylococcus aureus Skin Infection Improves the Course of Subsequent Endogenous S. aureus Bacteremia in Mice.

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    Sanne van den Berg

    Full Text Available Staphylococcus aureus carriers with S. aureus bacteremia may have a reduced mortality risk compared to non-carriers. A role for the immune system is suggested. Here, we study in mice the effect of mild S. aureus skin infection prior to endogenous or exogenous S. aureus bacteremia, and evaluate protection in relation to anti-staphylococcal antibody levels. Skin infections once or twice by a clinical S. aureus isolate (isolate P or S. aureus strain 8325-4 were induced in mice free of S. aureus and anti-staphylococcal antibodies. Five weeks later, immunoglobulin G (IgG levels in blood against 25 S. aureus antigens were determined, and LD50 or LD100 bacteremia caused by S. aureus isolate P was induced. S. aureus skin infections led to elevated levels of anti-staphylococcal IgG in blood. One skin infection improved the course of subsequent severe endogenous bacteremia only. A second skin infection further improved animal survival rate, which was associated with increased pre-bacteremia IgG levels against Efb, IsaA, LukD, LukE, Nuc, PrsA and WTA. In conclusion, S. aureus isolate P skin infection in mice reduces the severity of subsequent endogenous S. aureus bacteremia only. Although cellular immune effects cannot be rules out, anti-staphylococcal IgG against specified antigens may contribute to this effect.

  3. Rapid, Culture-Free Detection of Staphylococcus aureus Bacteremia

    Science.gov (United States)

    Burghardt, Elliot L.; Flenker, Katie S.; Clark, Karen C.; Miguel, Jeff; Ince, Dilek; Winokur, Patricia; Ford, Bradley; McNamara, James O.

    2016-01-01

    S. aureus bacteremia (SAB) is a common condition with high rates of morbidity and mortality. Current methods used to diagnose SAB take at least a day, and often longer. Patients with suspected bacteremia must therefore be empirically treated, often unnecessarily, while assay results are pending. In this proof-of-concept study, we describe an inexpensive assay that detects SAB via the detection of micrococcal nuclease (an enzyme secreted by S. aureus) in patient plasma samples in less than three hours. In total, 17 patient plasma samples from culture-confirmed S. aureus bacteremic individuals were tested. 16 of these yielded greater nuclease assay signals than samples from uninfected controls or individuals with non-S. aureus bacteremia. These results suggest that a nuclease-detecting assay may enable the rapid and inexpensive diagnosis of SAB, which is expected to substantially reduce the mortality and morbidity that result from this condition. PMID:27305148

  4. Increased risk of arterial thromboembolic events after Staphylococcus aureus bacteremia

    DEFF Research Database (Denmark)

    Mejer, N; Gotland, N; Uhre, M L;

    2015-01-01

    OBJECTIVES: An association between infection and arterial thromboembolic events (ATE) has been suggested. Here we examined the risk of myocardial infarction (MI), stroke and other ATE after Staphylococcus aureus bacteremia (SAB). METHODS: Danish register-based nation-wide observational cohort study...

  5. Diabetes and risk of community-acquired Staphylococcus aureus bacteremia

    DEFF Research Database (Denmark)

    Smit, Jesper; Søgaard, Mette; Schønheyder, Henrik Carl;

    2016-01-01

    OBJECTIVE: Patients with diabetes may experience higher risk of Staphylococcus aureus bacteremia (SAB) than patients without diabetes due to decreased immunity or coexisting morbidities. We investigated the risk of community-acquired (CA) SAB in persons with and without diabetes. DESIGN: Using...

  6. Characterization of Methicillin-Resistant Staphylococcus aureus Isolates from Patients with Persistent or Recurrent Bacteremia

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    Henry Wong

    2014-01-01

    Full Text Available BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA bloodstream infections (BSI are associated with considerable morbidity and mortality, especially with persistent (PB or recurrent bacteremia (RB.

  7. Novel structurally designed vaccine for S. aureus α-hemolysin: protection against bacteremia and pneumonia.

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    Rajan P Adhikari

    Full Text Available Staphylococcus aureus (S. aureus is a human pathogen associated with skin and soft tissue infections (SSTI and life threatening sepsis and pneumonia. Efforts to develop effective vaccines against S. aureus have been largely unsuccessful, in part due to the variety of virulence factors produced by this organism. S. aureus alpha-hemolysin (Hla is a pore-forming toxin expressed by most S. aureus strains and reported to play a key role in the pathogenesis of SSTI and pneumonia. Here we report a novel recombinant subunit vaccine candidate for Hla, rationally designed based on the heptameric crystal structure. This vaccine candidate, denoted AT-62aa, was tested in pneumonia and bacteremia infection models using S. aureus strain Newman and the pandemic strain USA300 (LAC. Significant protection from lethal bacteremia/sepsis and pneumonia was observed upon vaccination with AT-62aa along with a Glucopyranosyl Lipid Adjuvant-Stable Emulsion (GLA-SE that is currently in clinical trials. Passive transfer of rabbit immunoglobulin against AT-62aa (AT62-IgG protected mice against intraperitoneal and intranasal challenge with USA300 and produced significant reduction in bacterial burden in blood, spleen, kidney, and lungs. Our Hla-based vaccine is the first to be reported to reduce bacterial dissemination and to provide protection in a sepsis model of S. aureus infection. AT62-IgG and sera from vaccinated mice effectively neutralized the toxin in vitro and AT62-IgG inhibited the formation of Hla heptamers, suggesting antibody-mediated neutralization as the primary mechanism of action. This remarkable efficacy makes this Hla-based vaccine a prime candidate for inclusion in future multivalent S. aureus vaccine. Furthermore, identification of protective epitopes within AT-62aa could lead to novel immunotherapy for S. aureus infection.

  8. Changing epidemiology of pediatric Staphylococcus aureus bacteremia in Denmark from 1971 through 2000

    DEFF Research Database (Denmark)

    Frederiksen, Marianne Sjølin; Espersen, Frank; Frimodt-Møller, Niels;

    2007-01-01

    BACKGROUND: Staphylococcus aureus is known to be a leading cause of bacteremia in childhood, and is associated with severe morbidity and increased mortality. To determine developments in incidence and mortality rates, as well as risk factors associated with outcome, we analyzed data from 1971...... through 2000. METHODS: Nationwide registration of S. aureus bacteremia (SAB) among children and adolescents from birth to 20 years of age was performed. Data on age, sex, source of bacteremia, comorbidity and outcome were extracted from discharge records. Rates were population adjusted and risk factors...... and improved treatment modalities. However, incidence rates have increased significantly in the same period, underscoring that S. aureus remains an important invasive pathogen....

  9. Staphylococcus aureus bacteriuria as a prognosticator for outcome of Staphylococcus aureus bacteremia: a case-control study

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    Weinstein Robert A

    2010-07-01

    Full Text Available Abstract Background When Staphylococcus aureus is isolated in urine, it is thought to usually represent hematogenous spread. Because such spread might have special clinical significance, we evaluated predictors and outcomes of S. aureus bacteriuria among patients with S. aureus bacteremia. Methods A case-control study was performed at John H. Stroger Jr. Hospital of Cook County among adult inpatients during January 2002-December 2006. Cases and controls had positive and negative urine cultures, respectively, for S. aureus, within 72 hours of positive blood culture for S. aureus. Controls were sampled randomly in a 1:4 ratio. Univariate and multivariable logistic regression analyses were done. Results Overall, 59% of patients were African-American, 12% died, 56% of infections had community-onset infections, and 58% were infected with methicillin-susceptible S. aureus (MSSA. Among 61 cases and 247 controls, predictors of S. aureus bacteriuria on multivariate analysis were urological surgery (OR = 3.4, p = 0.06 and genitourinary infection (OR = 9.2, p = 0.002. Among patients who died, there were significantly more patients with bacteriuria than among patients who survived (39% vs. 17%; p = 0.002. In multiple Cox regression analysis, death risks in bacteremic patients were bacteriuria (hazard ratio 2.9, CI 1.4-5.9, p = 0.004, bladder catheter use (2.0, 1.0-4.0, p = 0.06, and Charlson score (1.1, 1.1-1.3, p = 0.02. Neither length of stay nor methicillin-resistant Staphylococcus aureus (MRSA infection was a predictor of S. aureus bacteriuria or death. Conclusions Among patients with S. aureus bacteremia, those with S. aureus bacteriuria had 3-fold higher mortality than those without bacteriuria, even after adjustment for comorbidities. Bacteriuria may identify patients with more severe bacteremia, who are at risk of worse outcomes.

  10. Bacteremia

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    ... School Lunch Lines FDA Cracks Down on Antibacterial Soaps Health Tip: Schedule a Back-to-School Dental ... from the infected site, causing bacteremia. In some bacterial infections , such as pneumonia and skin abscesses , bacteria ...

  11. Nasal Carriage as a Source of agr-Defective Staphylococcus aureus Bacteremia

    OpenAIRE

    Smyth, Davida S.; Kafer, Jared M.; Wasserman, Gregory A.; Velickovic, Lili; Mathema, Barun; Robert S Holzman; Knipe, Tiffany A.; Becker, Karsten; von Eiff, Christof; Peters, Georg; Chen, Liang; Kreiswirth, Barry N.; Novick, Richard P.; Shopsin, Bo

    2012-01-01

    Inactivating mutations in the Staphylococcus aureus virulence regulator agr are associated with worse outcomes in bacteremic patients. However, whether agr dysfunction is primarily a cause or a consequence of early bacteremia is unknown. Analysis of 158 paired S. aureus clones from blood and nasal carriage sites in individual patients revealed that recovery of an agr-defective mutant from blood was usually predicted by the agr functionality of carriage isolates. Many agr-positive blood isolat...

  12. Use of Glucocorticoids and Risk of Community-Acquired Staphylococcus aureus Bacteremia

    DEFF Research Database (Denmark)

    Smit, Jesper; Kaasch, Achim J; Søgaard, Mette;

    2016-01-01

    OBJECTIVE: To investigate whether the use of systemic glucocorticoids is a risk factor for community-acquired Staphylococcus aureus bacteremia (CA-SAB). PATIENTS AND METHODS: We used population-based medical registries in Northern Denmark to conduct a case-control study including all adults...

  13. Course and Outcome of Bacteremia Due to Staphylococcus Aureus: Evaluation of Different Clinical Case Definitions

    NARCIS (Netherlands)

    S. Lautenschlager; C. Herzog; W. Zimmerli

    1993-01-01

    textabstractIn a retrospective survey of patients hospitalized in the University Hospital of Basel, Switzerland, the course and outcome of 281 cases of true bacteremia due to Staphylococcus aureus over a 7-year period were analyzed. The main purpose was to evaluate different case definitions. In 78%

  14. Staphylococcus aureus bacteremia: what is the impact of oxacillin resistance on mortality?

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    V.C. Cassettari

    2005-02-01

    Full Text Available In order to analyse the impact of oxacillin resistance on the mortality of Staphylococcus aureus bacteremia, and to assess the antimicrobial susceptibility of community-acquired strains in two large university hospitals (the Instituto do Coração do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo and the Instituto Central do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, we carried out a four-month-long prospective cohort study, which included 163 consecutive cases of S. aureus bacteremia. Of these, 140 (85.9% were hospital-acquired, 9 (5.5% were community-acquired and 14 (8.6% were of indeterminate origin. No cases of community-acquired infection by oxacillin-resistant S. aureus was identified. Among hospital-acquired infections, oxacillin-resistant S. aureus was responsible for 64.3% of cases. Mortality up to 15 days after diagnosis of bacteremia was 27% (18/67 for infections caused by susceptible strains and 33% (32/96 for infections caused by oxacillin-resistant strains (p=0.10. The following independent risk factors for the acquisition of oxacillin-resistant S. aureus were identified in multiple logistical regression analysis: age over 60 years, use of corticoids; presence of a central vascular catheter, and previous use of antibiotics.

  15. Treating Central Catheter-Associated Bacteremia Due to Methicillin-Resistant Staphylococcus aureus: Beyond Vancomycin.

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    Holt, Shannon; Thompson-Brazill, Kelly A; Sparks, E Ryan; Lipetzky, Juliana

    2016-08-01

    Methicillin-resistant Staphylococcus aureus is a frequent cause of hospital-associated infections, including central catheter-associated bacteremia. Vancomycin has been the drug of choice for treating this type of bacteremia for decades in patients who have no contraindications to the antibiotic. However, resistance to vancomycin is an emerging problem. Newer antibiotics approved by the Food and Drug Administration have activity against methicillin-resistant S aureus Some of the antibiotics also have activity against strains of S aureus that are intermediately susceptible or resistant to vancomycin. This article uses a case study to highlight the clinical signs of vancomycin failure and describes the indications for and appropriate use of alternative antimicrobials such as ceftaroline, daptomycin, linezolid, tigecycline, and telavancin. (Critical Care Nurse 2016;36[4]:46-57). PMID:27481801

  16. Future challenges and treatment of Staphylococcus aureus bacteremia with emphasis on MRSA

    DEFF Research Database (Denmark)

    Rasmussen, Rasmus V; Fowler, Vance G; Skov, Robert;

    2011-01-01

    . Compounding this problem is the growing prevalence of methicillin-resistant S. aureus (MRSA) and the dwindling efficacy of vancomycin, long the treatment of choice for this pathogen. Despite the recent availability of several new antibiotics for S. aureus, new strategies for treatment and prevention......Staphylococcus aureus bacteremia (SAB) is an urgent medical problem due to its growing frequency and its poor associated outcome. As healthcare delivery increasingly involves invasive procedures and implantable devices, the number of patients at risk for SAB and its complications is likely to grow...

  17. Distinguishing Complicated from Uncomplicated Bacteremia Caused by Staphylococcus aureus: The Value of "New" and "Old" Serological Tests

    NARCIS (Netherlands)

    H.A. Verbrugh (Henri); W.H.F. Goessens (Wil); M.F. Michel; R. Peters (Roel)

    1986-01-01

    textabstractAntibody responses to staphylococcal α-toxin, cell wall teichoic acid, and cell wall peptodoglycan were measured in 259 serum samples from 74 consecutive patients with Staphylococcus aureus bacteremia. All patients with complicated bacteremia were seropositive in at least one of three te

  18. Genome Sequences of Sequence Type 45 (ST45) Persistent Methicillin-Resistant Staphylococcus aureus (MRSA) Bacteremia Strain 300-169 and ST45 Resolving MRSA Bacteremia Strain 301-188

    OpenAIRE

    Hernandez, David; Seidl, Kati; Corvaglia, Anna-Rita; Bayer, Arnold S.; Xiong, Yan Q.; Francois, Patrice

    2014-01-01

    Persistent methicillin-resistant Staphylococcus aureus (MRSA) bacteremia (positive blood cultures after ≥7 days) represents a challenging subset of invasive MRSA infections. The comparison of genome sequences of persistent (300-169) and resolving (301-188) MRSA bacteremia isolates with similar genetic background (sequence type 45 [ST45]) will help us to better understand underlying mechanisms of persistent MRSA bacteremia.

  19. Staphylococcal Enterotoxin P Predicts Bacteremia in Hospitalized Patients Colonized With Methicillin-Resistant Staphylococcus aureus

    Science.gov (United States)

    Calderwood, Michael S.; Desjardins, Christopher A.; Sakoulas, George; Nicol, Robert; DuBois, Andrea; Delaney, Mary L.; Kleinman, Ken; Cosimi, Lisa A.; Feldgarden, Michael; Onderdonk, Andrew B.; Birren, Bruce W.; Platt, Richard; Huang, Susan S.

    2014-01-01

    Background. Methicillin-resistant Staphylococcus aureus (MRSA) colonization predicts later infection, with both host and pathogen determinants of invasive disease. Methods. This nested case-control study evaluates predictors of MRSA bacteremia in an 8–intensive care unit (ICU) prospective adult cohort from 1 September 2003 through 30 April 2005 with active MRSA surveillance and collection of ICU, post-ICU, and readmission MRSA isolates. We selected MRSA carriers who did (cases) and those who did not (controls) develop MRSA bacteremia. Generating assembled genome sequences, we evaluated 30 MRSA genes potentially associated with virulence and invasion. Using multivariable Cox proportional hazards regression, we assessed the association of these genes with MRSA bacteremia, controlling for host risk factors. Results. We collected 1578 MRSA isolates from 520 patients. We analyzed host and pathogen factors for 33 cases and 121 controls. Predictors of MRSA bacteremia included a diagnosis of cancer, presence of a central venous catheter, hyperglycemia (glucose level, >200 mg/dL), and infection with a MRSA strain carrying the gene for staphylococcal enterotoxin P (sep). Receipt of an anti-MRSA medication had a significant protective effect. Conclusions. In an analysis controlling for host factors, colonization with MRSA carrying sep increased the risk of MRSA bacteremia. Identification of risk-adjusted genetic determinants of virulence may help to improve prediction of invasive disease and suggest new targets for therapeutic intervention. PMID:24041793

  20. Elevated soluble urokinase plasminogen activator receptor (suPAR) predicts mortality in Staphylococcus aureus bacteremia

    DEFF Research Database (Denmark)

    Mölkänen, T; Ruotsalainen, E; Thorball, C W;

    2011-01-01

    are scarce. To elucidate the role of suPAR in a common bacteremic infection, the serum suPAR levels in 59 patients with Staphylococcus aureus bacteremia (SAB) were measured using the suPARnostic ELISA assay and associations to 1-month mortality and with deep infection focus were analyzed. On day three, after......The soluble form of urokinase-type plasminogen activator receptor (suPAR) is a new inflammatory marker. High suPAR levels have been shown to associate with mortality in cancer and in chronic infections like HIV and tuberculosis, but reports on the role of suPAR in acute bacteremic infections......PAR levels as compared to patients with no deep infection focus. suPAR was found to be prognostic for mortality in receiver operator characteristic (ROC) curve analysis, which was not observed for serum C-reactive protein (CRP); the area under the curve (AUC) for suPAR was 0.754 (95% confidence interval [CI...

  1. Clinical and Microbiologic Analysis of the Risk Factors for Mortality in Patients with Heterogeneous Vancomycin-Intermediate Staphylococcus aureus Bacteremia

    Science.gov (United States)

    Chong, Yong Pil; Park, Ki-Ho; Kim, Eun Sil; Kim, Mi-Na; Kim, Sung-Han; Lee, Sang-Oh; Choi, Sang-Ho; Jeong, Jin-Yong; Woo, Jun Hee

    2015-01-01

    The prevalence of the heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA) phenotype among methicillin-resistant S. aureus (MRSA) blood isolates can reach 38%. hVISA bacteremia is known to be associated with vancomycin treatment failure, including persistent bacteremia. We conducted this study to evaluate risk factors for 12-week mortality in patients with hVISA bacteremia through a detailed clinical and microbiological analysis of a prospective cohort of patients with S. aureus bacteremia. All isolates were collected on the first day of bacteremia and subjected to population analysis profiling for hVISA detection, genotyping, and PCR analysis for 39 virulence factors. Of 382 patient with MRSA bacteremia, 121 (32%) had hVISA bacteremia. Deceased patients were more likely to have hematologic malignancy (P = 0.033), ultimately or rapidly fatal disease (P = 0.007), and a higher Pitt bacteremia score (P = 0.010) than surviving patients. The sequence type 239 (ST239) clonal type and definitive linezolid treatment were associated with a trend toward reduced mortality (P = 0.061 and 0.072, respectively), but a high vancomycin MIC (≥2 mg/liter) was not associated with increased mortality (P = 0.368). In a multivariate analysis, ultimately or rapidly fatal disease (adjusted odds ratio [aOR], 2.80; 95% confidence interval [CI], 1.14 to 6.85) and a high Pitt bacteremia score (aOR, 1.26; 95% CI, 1.07 to 1.48) were independent risk factors for mortality. Hematologic malignancy was associated with a trend toward increased mortality (P = 0.094), and ST239 was associated with a trend toward reduced mortality (P = 0.095). Our study suggests that ST239 hVISA is a possible predictor of survival in hVISA bacteremia. PMID:25845875

  2. Risk and prognosis of Staphylococcus aureus bacteremia among individuals with and without end-stage renal disease

    DEFF Research Database (Denmark)

    Nielsen, Lise H; Jensen-Fangel, Søren; Benfield, Thomas;

    2015-01-01

    BACKGROUND: Staphylococcus aureus is a leading cause of bloodstream infections among hemodialysis patients and of exit-site infections among peritoneal dialysis patients. However, the risk and prognosis of Staphylococcus aureus bacteremia among end-stage renal disease patients have not been delin...

  3. Immune dysfunction prior to Staphylococcus aureus bacteremia is a determinant of long-term mortality.

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    Jared A Greenberg

    Full Text Available PURPOSE: The clinical implications for patients who survive serious infections are not well understood. It has been hypothesized that the excess mortality for survivors of sepsis observed in epidemiological studies is due to increased vulnerability to subsequent infections. We undertook this study to identify characteristics of patients who are at high risk for death after surviving a common type of blood-stream infection. MATERIALS AND METHODS: At a single academic medical center, 237 patients with Staphylococcus aureus bacteremia admitted during a three-year period were retrospectively identified. The primary outcomes were 30-day and 31 to 90-day mortality after the first positive blood culture. The primary predictor variable of interest was clinical immune dysfunction prior to bacteremia. RESULTS: The 30-day mortality was not significantly different for patients with and without prior immune dysfunction. However, during days 31 to 90, 11 patients (20% with prior immune dysfunction compared to 10 patients (8.6% without prior immune dysfunction died (OR 2.59, 95% CI 1.03-6.53, p = 0.04. In a Cox-proportional hazard model controlling for age, there was a significant association between prior immune dysfunction and greater 31 to 90 day mortality (HR 2.44, 95% CI 1.01-5.90, p = 0.05 and a non-significant trend towards occurrence of subsequent infections and greater 31 to 90 day mortality (HR 2.12, 95% CI 0.89-5.07, p = 0.09. CONCLUSIONS: Patients with prior immune dysfunction are at high risk for death 31 to 90 days, but not <30 days, after S. aureus bacteremia. Further investigation is needed to determine if this finding is due to poor prognosis of chronic disease or increased vulnerability to subsequent infections.

  4. Comparative effectiveness of nafcillin or cefazolin versus vancomycin in methicillin-susceptible Staphylococcus aureus bacteremia

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    McGregor Jessina C

    2011-10-01

    Full Text Available Abstract Background The high prevalence of methicillin-resistant S. aureus (MRSA has led clinicians to select antibiotics that have coverage against MRSA, usually vancomycin, for empiric therapy for suspected staphylococcal infections. Clinicians often continue vancomycin started empirically even when methicillin-susceptible S. aureus (MSSA strains are identified by culture. However, vancomycin has been associated with poor outcomes such as nephrotoxicity, persistent bacteremia and treatment failure. The objective of this study was to compare the effectiveness of vancomycin versus the beta-lactam antibiotics nafcillin and cefazolin among patients with MSSA bacteremia. The outcome of interest for this study was 30-day in-hospital mortality. Methods This retrospective cohort study included all adult in-patients admitted to a tertiary-care facility between January 1, 2003 and June 30, 2007 who had a positive blood culture for MSSA and received nafcillin, cefazolin or vancomycin. Cox proportional hazard models were used to assess independent mortality hazards comparing nafcillin or cefazolin versus vancomycin. Similar methods were used to estimate the survival benefits of switching from vancomycin to nafcillin or cefazolin versus leaving patients on vancomycin. Each model included statistical adjustment using propensity scores which contained variables associated with an increased propensity to receive vancomycin. Results 267 patients were included; 14% (38/267 received nafcillin or cefazolin, 51% (135/267 received both vancomycin and either nafcillin or cefazolin, and 35% (94/267 received vancomycin. Thirty (11% died within 30 days. Those receiving nafcillin or cefazolin had 79% lower mortality hazards compared with those who received vancomycin alone (adjusted hazard ratio (HR: 0.21; 95% confidence interval (CI: 0.09, 0.47. Among the 122 patients who initially received vancomycin empirically, those who were switched to nafcillin or cefazolin (66

  5. Active immunization with an octa-valent Staphylococcus aureus antigen mixture in models of S. aureus bacteremia and skin infection in mice.

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    Sanne van den Berg

    Full Text Available Proteomic studies with different Staphylococcus aureus isolates have shown that the cell surface-exposed and secreted proteins IsaA, LytM, Nuc, the propeptide of Atl (pro-Atl and four phenol-soluble modulins α (PSMα are invariantly produced by this pathogen. Therefore the present study was aimed at investigating whether these proteins can be used for active immunization against S. aureus infection in mouse models of bacteremia and skin infection. To this end, recombinant His-tagged fusions of IsaA, LytM, Nuc and pro-Atl were isolated from Lactococcus lactis or Escherichia coli, while the PSMα1-4 peptides were chemically synthesized. Importantly, patients colonized by S. aureus showed significant immunoglobulin G (IgG responses against all eight antigens. BALB/cBYJ mice were immunized subcutaneously with a mixture of the antigens at day one (5 μg each, and boosted twice (25 μg of each antigen with 28 days interval. This resulted in high IgG responses against all antigens although the response against pro-Atl was around one log lower compared to the other antigens. Compared to placebo-immunized mice, immunization with the octa-valent antigen mixture did not reduce the S. aureus isolate P load in blood, lungs, spleen, liver, and kidneys in a bacteremia model in which the animals were challenged for 14 days with a primary load of 3 × 10(5 CFU. Discomfort scores and animal survival rates over 14 days did not differ between immunized mice and placebo-immunized mice upon bacteremia with S. aureus USA300 (6 × 10(5 CFU. In addition, this immunization did not reduce the S. aureus isolate P load in mice with skin infection. These results show that the target antigens are immunogenic in both humans and mice, but in the used animal models do not result in protection against S. aureus infection.

  6. Community-associated Methicillin-resistant Staphylococcus aureus Bacteremia and Endocarditis among HIV Patients: A cohort study

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    Stine Oscar C

    2011-10-01

    Full Text Available Abstract Background HIV patients are at increased risk of development of infections and infection-associated poor health outcomes. We aimed to 1 assess the prevalence of USA300 community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA among HIV-infected patients with S. aureus bloodstream infections and. 2 determine risk factors for infective endocarditis and in-hospital mortality among patients in this population. Methods All adult HIV-infected patients with documented S. aureus bacteremia admitted to the University of Maryland Medical Center between January 1, 2003 and December 31, 2005 were included. CA-MRSA was defined as a USA300 MRSA isolate with the MBQBLO spa-type motif and positive for both the arginine catabolic mobile element and Panton-Valentin Leukocidin. Risk factors for S. aureus-associated infective endocarditis and mortality were determined using logistic regression to calculate odds ratios (OR and 95% confidence intervals (CI. Potential risk factors included demographic variables, comorbid illnesses, and intravenous drug use. Results Among 131 episodes of S. aureus bacteremia, 85 (66% were MRSA of which 47 (54% were CA-MRSA. Sixty-three patients (48% developed endocarditis and 10 patients (8% died in the hospital on the index admission Patients with CA-MRSA were significantly more likely to develop endocarditis (OR = 2.73, 95% CI = 1.30, 5.71. No other variables including comorbid conditions, current receipt of antiretroviral therapy, pre-culture severity of illness, or CD4 count were significantly associated with endocarditis and none were associated with in-hospital mortality. Conclusions CA-MRSA was significantly associated with an increased incidence of endocarditis in this cohort of HIV patients with MRSA bacteremia. In populations such as these, in which the prevalence of intravenous drug use and probability of endocarditis are both high, efforts must be made for early detection, which may improve

  7. Chronic heart failure and mortality in patients with community-acquired Staphylococcus aureus bacteremia

    DEFF Research Database (Denmark)

    Smit, Jesper; Adelborg, Kasper; Thomsen, Reimar Wernich;

    2016-01-01

    analysis, we computed hazard ratios as estimates of mortality rate ratios (MRRs) overall and stratified by CHF-related conditions (e.g., cardiomyopathy and valvular heart disease), CHF severity (defined by daily dosage of loop-diuretics), and CHF duration while adjusting for potential confounders. RESULTS...... patients with valvular heart disease (aMRR = 1.73 (95 % CI, 1.26-2.38)), patients with daily loop-diuretic dosages of 81-159 mg/day (aMRR = 1.55 (95 % CI, 1.11-2.14)) and ≥160 mg/day (aMRR = 1.62 (95 % CI, 1.21-2.18)), and among patients with <3 years of CHF duration (aMRR = 1.43 (95 % CI, 1......BACKGROUND: Patients with chronic heart failure (CHF) may experience higher mortality of Staphylococcus aureus bacteremia (SAB) than patients without CHF due to insufficient cardiovascular responses during systemic infection. We investigated 90-day mortality in SAB patients with and without CHF...

  8. Vertebral osteomyelitis caused by vancomycin-tolerant methicillin-resistant Staphylococcus aureus bacteremia: Experience with teicoplanin plus fosfomycin combination therapy.

    Science.gov (United States)

    Lee, Wen-Sen; Chen, Yen-Chuo; Chen, Hung-Ping; Chen, Tso-Hsiao; Cheng, Chung-Yi

    2016-08-01

    An 85-year-old female presented with fever and consciousness disturbance for 3 days. The patient's blood culture subsequently revealed persistent methicillin-resistant Staphylococcus aureus (MRSA) bacteremia despite the administration of vancomycin or teicoplanin monotherapy. Gallium inflammation scan and magnetic resonance image of the spine disclosed osteomyelitis and discitis at the level of L4-5. Surgical debridement was not feasible in this debilitated patient. Because of the creeping minimal inhibitory concentration of vancomycin of the causative isolate (1.5 μg/mL) and clinical failure with glycopeptide monotherapy, we changed the antibiotic therapy to a fosfomycin and teicoplanin combination therapy. The patient showed improved clinical response in terms of her enhanced consciousness as well as subsidence of persisted bacteremia. Despite the potential side effects of fosfomycin (such as diarrhea and hypernatremia), it combined with a glycopeptide may be an alternative therapy for invasive refractory MRSA infections. PMID:24269007

  9. Comparison of cefazolin versus oxacillin for treatment of complicated bacteremia caused by methicillin-susceptible Staphylococcus aureus.

    Science.gov (United States)

    Li, Julius; Echevarria, Kelly L; Hughes, Darrel W; Cadena, Jose A; Bowling, Jason E; Lewis, James S

    2014-09-01

    Contrary to prior case reports that described occasional clinical failures with cefazolin for methicillin-susceptible Staphylococcus aureus (MSSA) infections, recent studies have demonstrated no difference in outcomes between cefazolin and antistaphylococcal penicillins for the treatment of MSSA bacteremia. While promising, these studies described low frequencies of high-inoculum infections, such as endocarditis. This retrospective study compares clinical outcomes of cefazolin versus oxacillin for complicated MSSA bacteremia at two tertiary care hospitals between January 2008 and June 2012. Fifty-nine patients treated with cefazolin and 34 patients treated with oxacillin were included. Osteoarticular (41%) and endovascular (20%) sources were the predominant sites of infection. The rates of clinical cure at the end of therapy were similar between cefazolin and oxacillin (95% versus 88%; P=0.25), but overall failure at 90 days was higher in the oxacillin arm (47% versus 24%; P=0.04). Failures were more likely to have received surgical interventions (63% versus 40%; P=0.05) and to have an osteoarticular source (57% versus 33%; P=0.04). Failures also had a longer duration of bacteremia (7 versus 3 days; P=0.0002), which was the only predictor of failure. Antibiotic selection was not predictive of failure. Rates of adverse drug events were higher in the oxacillin arm (30% versus 3%; P=0.0006), and oxacillin was more frequently discontinued due to adverse drug events (21% versus 3%; P=0.01). Cefazolin appears similar to oxacillin for the treatment of complicated MSSA bacteremia but with significantly improved safety. The higher rates of failure with oxacillin may have been confounded by other patient factors and warrant further investigation. PMID:24936596

  10. Clinical prediction rules in Staphylococcus aureus bacteremia demonstrate the usefulness of reporting likelihood ratios in infectious diseases.

    Science.gov (United States)

    Bai, A D; Showler, A; Burry, L; Steinberg, M; Tomlinson, G A; Bell, C M; Morris, A M

    2016-09-01

    Infectious diseases specialists often use diagnostic tests to assess the probability of a disease based on knowledge of the diagnostic properties. It has become standard for published studies on diagnostic tests to report sensitivity, specificity and predictive values. Likelihood ratios are often omitted. We compared published clinical prediction rules in Staphylococcus aureus bacteremia to illustrate the importance of likelihood ratios. We performed a narrative review comparing published clinical prediction rules used for excluding endocarditis in S. aureus bacteremia. Of nine published clinical prediction rules, only three studies reported likelihood ratios. Many studies concluded that the clinical prediction rule could safely exclude endocarditis based on high sensitivity and high negative predictive value. Of the studies with similar high sensitivity and high negative predictive value, calculated negative likelihood ratios were able to differentiate and identify the best clinical prediction rule for excluding endocarditis. Compared to sensitivity, specificity and predictive values, likelihood ratios can be more directly used to interpret diagnostic test results to assist in ruling in or ruling out a disease. Therefore, a new standard should be set to include likelihood ratios in reporting of diagnostic tests in infectious diseases research. PMID:27357965

  11. Long-term mortality and causes of death associated with Staphylococcus aureus bacteremia. A matched cohort study

    DEFF Research Database (Denmark)

    Gotland, Nanja; Uhre, Marie-Louise; Mejer, N;

    2016-01-01

    respiratory disease, nervous system disease, unknown causes, psychiatric disorders, cardiovascular disease and senility. Over time, rates of death decreased or were stable for all disease categories except for musculoskeletal and skin disease where a trend towards an increase was seen. CONCLUSION: Long......-term mortality after SAB was high but decreased over time. SAB cases were more likely to die of eight specific causes of death and less likely to die of five other causes of death compared to controls. Causes of death decreased for most disease categories. Risk factors associated with long-term mortality were......OBJECTIVES: Data describing long-term mortality in patients with Staphylococcus aureus bacteremia (SAB) is scarce. This study investigated risk factors, causes of death and temporal trends in long-term mortality associated with SAB. METHODS: Nationwide population-based matched cohort study...

  12. Future challenges and treatment of Staphylococcus aureus bacteremia with emphasis on MRSA

    DEFF Research Database (Denmark)

    Rasmussen, Rasmus V; Fowler, Vance G; Skov, Robert;

    2011-01-01

    . Compounding this problem is the growing prevalence of methicillin-resistant S. aureus (MRSA) and the dwindling efficacy of vancomycin, long the treatment of choice for this pathogen. Despite the recent availability of several new antibiotics for S. aureus, new strategies for treatment and prevention...

  13. Genetic polymorphism of the C-reactive protein (CRP) gene and a deep infection focus determine maximal serum CRP level in Staphylococcus aureus bacteremia

    OpenAIRE

    Mölkänen, T.; Rostila, A.; Ruotsalainen, E.; Alanne, M.; Perola, M.; Järvinen, A.

    2010-01-01

    Abstract C-reactive protein (CRP) is widely used in early detection of sepsis or organ dysfunction. Several single nucleotide polymorphisms (SNPs) in the CRP gene are shown to be associated with variability of basal CRP. To clarify the effect of these SNPs to CRP response in systemic infections, we compared genetic and clinical data on patients with Staphylococcus aureus bacteremia (SAB). Six SNPs in the CRP gene region (rs2794521, rs30912449, rs1800947, rs1130864, rs1205 and rs309...

  14. Seasonal Variation of Escherichia coli, Staphylococcus aureus, and Streptococcus pneumoniae Bacteremia According to Acquisition and Patient Characteristics: A Population-Based Study.

    Science.gov (United States)

    Gradel, Kim Oren; Nielsen, Stig Lønberg; Pedersen, Court; Knudsen, Jenny Dahl; Østergaard, Christian; Arpi, Magnus; Jensen, Thøger Gorm; Kolmos, Hans Jørn; Søgaard, Mette; Lassen, Annmarie Touborg; Schønheyder, Henrik Carl

    2016-08-01

    OBJECTIVE Seasonal variation is a characteristic of many infectious diseases, but relatively little is known about determinants thereof. We studied the impact of place of acquisition and patient characteristics on seasonal variation of bacteremia caused by the 3 most common pathogens. DESIGN Seasonal variation analysis. METHODS In 3 Danish health regions (2.3 million total inhabitants), patients with bacteremia were identified from 2000 through 2011 using information from laboratory information systems. Analyses were confined to Escherichia coli, Staphylococcus aureus, and Streptococcus pneumoniae. Additional data were obtained from the Danish National Hospital Registry for the construction of admission histories and calculation of the Charlson comorbidity index (CCI). Bacteremias were categorized as community acquired, healthcare associated (HCA), and hospital acquired. We defined multiple subgroups by combining the following characteristics: species, acquisition, age group, gender, CCI level, and location of infection. Assuming a sinusoidal model, seasonal variation was assessed by the peak-to-trough (PTT) ratio with a 95% confidence interval (CI). RESULTS In total, we included 16,006 E. coli, 6,924 S. aureus, and 4,884 S. pneumoniae bacteremia cases. For E. coli, the seasonal variation was highest for community-acquired cases (PTT ratio, 1.24; 95% CI, 1.17-1.32), was diminished for HCA (PTT ratio, 1.14; 95% CI, 1.04-1.25), and was missing for hospital-acquired cases. No seasonal variation was observed for S. aureus. S. pneumoniae showed high seasonal variation, which did not differ according to acquisition (overall PTT ratio, 3.42; 95% CI, 3.10-3.83). CONCLUSIONS Seasonal variation was mainly related to the species although the place of acquisition was important for E. coli. Infect Control Hosp Epidemiol 2016;37:946-953. PMID:27142942

  15. Distinctive Cytokines as Biomarkers Predicting Fatal Outcome of Severe Staphylococcus aureus Bacteremia in Mice

    NARCIS (Netherlands)

    S. van den Berg (Sanne); J.D. Laman (Jon); L. Boon (Louis); M.T. ten Kate (Marian); G.J. de Knegt (Gerjo); R.M. Verdijk (Robert); H.A. Verbrugh (Henri); J.L. Nouwen (Jan); I.A.J.M. Bakker-Woudenberg (Irma)

    2013-01-01

    textabstractInvasive Staphylococcus aureus infections are frequently associated with bacteraemia. To support clinical decisions on antibiotic therapy, there is an urgent need for reliable markers as predictors of infection outcome. In the present study in mice, bacteraemia was established by intrave

  16. [Consensus document for the treatment of bacteremia and endocarditis caused by methicillin-resistent Staphylococcus aureus. Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica].

    Science.gov (United States)

    Gudiol, Francisco; Aguado, José María; Pascual, Alvaro; Pujol, Miquel; Almirante, Benito; Miró, José María; Cercenado, Emilia; Domínguez, María de Los Angeles; Soriano, Alex; Rodríguez-Baño, Jesús; Vallés, Jordi; Palomar, Mercedes; Tornos, Pilar; Bouza, Emilio

    2009-02-01

    Bacteremia and endocarditis due to methicillin-resistant Staphylococcus aureus (MRSA) are prevalent and clinically important. The rise in MRSA bacteremia and endocarditis is related with the increasing use of venous catheters and other vascular procedures. Glycopeptides have been the reference drugs for treating these infections. Unfortunately their activity is not completely satisfactory, particularly against MRSA strains with MICs > 1 microg/mL. The development of new antibiotics, such as linezolid and daptomycin, and the promise of future compounds (dalvabancin, ceftobiprole and telavancin) may change the expectatives in this field.The principal aim of this consensus document was to formulate several recommendations to improve the outcome of MRSA bacteremia and endocarditis, based on the latest reported scientific evidence. This document specifically analyzes the approach for three clinical situations: venous catheter-related bacteremia, persistent bacteremia, and infective endocarditis due to MRSA.

  17. Relationship between pathogenic, clinical, and virulence factors of Staphylococcus aureus in infective endocarditis versus uncomplicated bacteremia: a case-control study.

    Science.gov (United States)

    Gallardo-García, M M; Sánchez-Espín, G; Ivanova-Georgieva, R; Ruíz-Morales, J; Rodríguez-Bailón, I; Viñuela González, V; García-López, M V

    2016-05-01

    Pathogenic factors of Staphylococcus aureus (SA) in the development of infective endocarditis (IE) have not been sufficiently investigated. The purpose of this study was to analyze the pathogenesis and virulence factors of SA in patients with IE as compared to patients with uncomplicated bacteremia (un-BAC). This is a retrospective case-control study (2002-2014) performed at a tertiary hospital in Spain. Clinical and epidemiological factors were analyzed. We assessed the presence of toxin genes [toxic shock syndrome toxin 1 (tst-1) and enterotoxins A (etA), B (etB), and D (etD)] and the potential relationship between accessory gene regulator (agr) groups and the development of IE confirmed by polymerase chain reaction (PCR). Twenty-nine patients with IE were compared with 58 patients with uncomplicated S. aureus bacteremia (SAB). As many as 75.9 % of patients had community-acquired IE (p infection and severe sepsis or septic shock and IE. Also, a minimum inhibitory concentration (MIC) of vancomycin ≥1.5 μg/ml was found to be associated with IE. The agr group I was prevalent (55.2 % vs. 31.0 %; p = 0.030). No association was observed between toxin genes (tst-1, etA, etB, and etD) and IE. The superantigen (SAg) most frequently found in SA isolates was tst-1 (12.6 %). We found no association between toxin genes and IE, probably due to the small sample size. However, a direct relationship was found between agr I and the development of IE, which suggests that agr I strains may have more potential to cause IE. PMID:26951263

  18. Differential Expression and Roles of Staphylococcus aureus Virulence Determinants during Colonization and Disease

    OpenAIRE

    Jenkins, Amy; Diep, Binh An; Mai, Thuy T.; Vo, Nhung H.; Warrener, Paul; Suzich, Joann; Stover, C. Kendall; Sellman, Bret R.

    2015-01-01

    ABSTRACT Staphylococcus aureus is a Gram-positive, commensal bacterium known to asymptomatically colonize the human skin, nares, and gastrointestinal tract. Colonized individuals are at increased risk for developing S. aureus infections, which range from mild skin and soft tissue infections to more severe diseases, such as endocarditis, bacteremia, sepsis, and osteomyelitis. Different virulence factors are required for S. aureus to infect different body sites. In this study, virulence gene ex...

  19. Bacteremia in burned patients admitted to Sina Hospital, Tabriz, Iran

    Directory of Open Access Journals (Sweden)

    Parviz Saleh

    2014-11-01

    Full Text Available Introduction: One of the most important causes of mortality and morbidity in burn wards is infection, and it is the major reason of death in burn injuries. There are several reasons that make burn victims predisposed to infection. The current study aimed to investigate the role of different factors that have an effect on bacteremia occurrence in burn patients and factors which are relevant to mortality in these patients. Methods: This descriptive-analytic study conducted in a 1 year period in Sina Hospital, Tabriz University of Medical Sciences, Iran, and 81 burn were included. We collected patients’ data about their age, body weight, cause of burn, lesion color, place and percentage of burn by getting history and studying of their files. Then we documented all interventions. Blood tests and cultures and colonies criteria were recorded. Results: In this study, 39 patients were male (48.1%, and 42 was female (51.9%. Mean age was 32.06 ± 17.46 years. In patients without bacteremia, 57 patients did not need catheterization (89.1%, however in patients with bacteremia 9 patients demanded catheter insertion (52.9%. In patients with bacteremia 12 patients survived (70.9%, however in the without bacteremia group 56 patients survived (92.2%. Then, the relationship between type of burn, wound infection and bacterial species investigated, (P = 0.650, P = 0.210 and P = 0.110 respectively. Conclusion: We concluded, invasive interventions increased bacteremia susceptibility in our studied burned patients. Mortality rate is directly related to bacteremia prevalence and increased by extent of burn area in these patients. The three most frequent microbial agents responsible for bacteremia were Pseudomona aeruginosa, Klebsiella and Staphylococcus aureus.

  20. Active immunization with an octa-valent Staphylococcus aureus antigen mixture in models of S. aureus bacteremia and skin infection in mice

    NARCIS (Netherlands)

    Van Den Berg, S. (Sanne); Koedijk, D.G.A.M. (Dennis G. A. M.); Back, J.W. (Jaap Willem); J. Neef (Jolanda); A. Dreisbach (Annette); J.M. Dijl (Jan Maarten); I.A.J.M. Bakker-Woudenberg (Irma); G. Buist (Girbe)

    2015-01-01

    textabstractProteomic studies with different Staphylococcus aureus isolates have shown that the cell surface-exposed and secreted proteins IsaA, LytM, Nuc, the propeptide of Atl (pro-Atl) and four phenol-soluble modulins α (PSMα) are invariantly produced by this pathogen. Therefore the present study

  1. Active Immunization with an Octa-Valent Staphylococcus aureus Antigen Mixture in Models of S. aureus Bacteremia and Skin Infection in Mice

    NARCIS (Netherlands)

    van den Berg, Sanne; Koedijk, Dennis G. A. M.; Back, Jaap Willem; Neef, Jolanda; Dreisbach, Annette; van Dijl, Jan Maarten; Bakker-Woudenberg, Irma A. J. M.; Buist, Girbe

    2015-01-01

    Proteomic studies with different Staphylococcus aureus isolates have shown that the cell surface-exposed and secreted proteins IsaA, LytM, Nuc, the propeptide of Atl (pro-Atl) and four phenol-soluble modulins alpha (PSM alpha) are invariantly produced by this pathogen. Therefore the present study wa

  2. A recommendation to perform a blood culture before the administration of intravenous antibiotics increased the detection of Staphylococcus aureus bacteremia

    OpenAIRE

    Jogenfors, A.; Stark, L.; Svefors, J.; Löfgren, S; Malmvall, B.-E.; Matussek, A.

    2013-01-01

    In 2004, the Surviving Sepsis Campaign was launched to increase awareness and improve the outcome of severe sepsis. Accordingly, in Jönköping County, Sweden, a strong recommendation to perform a blood culture before the start of intravenous antibiotic treatment was introduced in 2007. Moreover, a reminder was included in the laboratory report to consult an infectious disease specialist when Staphylococcus aureus was isolated from a blood culture. Retrospectively, patients with at least one bl...

  3. Characterization of alpha-toxin hla gene variants, alpha-toxin expression levels, and levels of antibody to alpha-toxin in hemodialysis and postsurgical patients with Staphylococcus aureus bacteremia.

    Science.gov (United States)

    Sharma-Kuinkel, Batu K; Wu, Yuling; Tabor, David E; Mok, Hoyin; Sellman, Bret R; Jenkins, Amy; Yu, Li; Jafri, Hasan S; Rude, Thomas H; Ruffin, Felicia; Schell, Wiley A; Park, Lawrence P; Yan, Qin; Thaden, Joshua T; Messina, Julia A; Fowler, Vance G; Esser, Mark T

    2015-01-01

    Alpha-toxin is a major Staphylococcus aureus virulence factor. This study evaluated potential relationships between in vitro alpha-toxin expression of S. aureus bloodstream isolates, anti-alpha-toxin antibody in serum of patients with S. aureus bacteremia (SAB), and clinical outcomes in 100 hemodialysis and 100 postsurgical SAB patients. Isolates underwent spa typing and hla sequencing. Serum anti-alpha-toxin IgG and neutralizing antibody levels were measured by using an enzyme-linked immunosorbent assay and a red blood cell (RBC)-based hemolysis neutralization assay. Neutralization of alpha-toxin by an anti-alpha-toxin monoclonal antibody (MAb MEDI4893) was tested in an RBC-based lysis assay. Most isolates encoded hla (197/200; 98.5%) and expressed alpha-toxin (173/200; 86.5%). In vitro alpha-toxin levels were inversely associated with survival (cure, 2.19 μg/ml, versus failure, 1.09 μg/ml; P toxin-expressing S. aureus isolates (P toxin is highly conserved in clinical S. aureus isolates. Higher in vitro alpha-toxin levels were associated with a positive clinical outcome. Although patients infected with alpha-toxin-producing S. aureus exhibited higher anti-alpha-toxin antibody levels, these levels were not associated with a better clinical outcome in this study.

  4. Vancomycin 24-Hour Area under the Curve/Minimum Bactericidal Concentration Ratio as a Novel Predictor of Mortality in Methicillin-Resistant Staphylococcus aureus Bacteremia.

    Science.gov (United States)

    Britt, Nicholas S; Patel, Nimish; Horvat, Rebecca T; Steed, Molly E

    2016-05-01

    While previous studies have examined the association between vancomycin (VAN) exposure and MIC with regard to outcomes in methicillin-resistant Staphylococcus aureus bacteremia (MRSA-B), none have explored if a relationship exists with the VAN minimum bactericidal concentration (MBC). The objective of this study was to evaluate the VAN 24-h area under the curve (AUC24)/MBC ratio as a pharmacodynamic predictor of mortality. This retrospective cohort study included patients treated with VAN for MRSA-B with the primary outcome of 30-day all-cause mortality. Data collected included patient demographics, comorbidities, antimicrobial treatment data, therapeutic drug levels, and laboratory and microbiological data. Vancomycin MICs and MBCs were determined by Etest (MIC only) and broth microdilution (BMD). The vancomycin AUC24 was determined by pharmacokinetic maximum a posteriori probability Bayesian (MAP-Bayesian) analysis. The most significant breakpoint for 30-day mortality was determined by classification and regression tree (CART) analysis. The association between pharmacodynamic parameters (VAN AUC24/MICBMD, VAN AUC24/MICEtest, and AUC24/MBCBMD) and mortality were determined by χ(2) and multivariable Poisson regression. Overall mortality in this cohort (n = 53) was 20.8% (n = 11/53), and all corresponding MRSA blood isolates were VAN susceptible (MIC range, 0.5 to 2 μg/ml; MIC50, 1 μg/ml; MIC90, 1 μg/ml). The CART-derived breakpoints for mortality were 176 (VAN AUC24/MBC) and 334 (VAN AUC24/MICBMD). In multivariable analysis, the association between a VAN AUC24/MBC of ≥176 and survival persisted, but VAN AUC24/MICBMD values (≥334 or ≥400) were not associated with improved mortality. In conclusion, VAN AUC24/MBC was a more important predictor of 30-day mortality than VAN AUC24/MIC for MRSA-B. PMID:26953202

  5. Role of Monocytes in Experimental Staphylococcus aureus Endocarditis

    OpenAIRE

    Veltrop, Marcel H. A. M.; Bancsi, Maurice J. L. M. F.; Bertina, Rogier M.; Thompson, Jan

    2000-01-01

    In the pathogenesis of bacterial endocarditis (BE), the clotting system plays a cardinal role in the formation and maintenance of the endocardial vegetations. The extrinsic pathway is involved in the activation of the coagulation pathway with tissue factor (TF) as the key protein. Staphylococcus aureus is a frequently isolated bacterium from patients with BE. We therefore investigated whether S. aureus can induce TF activity (TFA) on fibrin-adherent monocytes, used as an in vitro model of BE....

  6. Role of nasopharyngeal colonization with and without bacteremia in the protection of infant rats against Haemophilus influenzae type b challenge.

    OpenAIRE

    Gilsdorf, J R; Ferrieri, P

    1985-01-01

    Nasopharyngeal colonization of infant rats with Haemophilus influenzae type b was investigated by two methods of intranasal inoculation. After traumatic instillation of the bacteria, 100% of the animals became colonized, compared with 75.5% of animals after atraumatic instillation. Among colonized rats, significantly more animals in the traumatic group developed bacteremia compared with those in the atraumatic group. Rats in the traumatic group had an onset of bacteremia at a mean of 2.6 days...

  7. The neglected role of antibody in protection against bacteremia caused by nontyphoidal strains of Salmonella in African children

    OpenAIRE

    MacLennan, Calman A.; Gondwe, Esther N.; Msefula, Chisomo L.; Kingsley, Robert A.; Thomson, Nicholas R.; White, Sarah A; Goodall, Margaret; Pickard, Derek J.; Graham, Stephen M.; Dougan, Gordon; Hart, C. Anthony; Molyneux, Malcolm E.; Drayson, Mark T.

    2008-01-01

    Nontyphoidal strains of Salmonella (NTS) are a common cause of bacteremia among African children. Cell-mediated immune responses control intracellular infection, but they do not protect against extracellular growth of NTS in the blood. We investigated whether antibody protects against NTS bacteremia in Malawian children, because we found this condition mainly occurs before 2 years of age, with relative sparing of infants younger than 4 months old. Sera from all healthy Malawian children teste...

  8. Nosocomial and Community-Acquired Staphylococcus Aureus Bacterimias from 1980 to 1993: Impact of Intravascular Devices and Methicillin Resistance

    NARCIS (Netherlands)

    J.P. Steinberg; C.C. Clarke; B.O. Hackman

    1996-01-01

    textabstractThe rate of nosocomial bacteremia due to Staphylococcus aureus has increased over the past decade, but trends in community-acquired S. aureus bacteremia are less certain. This hospital-based observational study compares nosocomial and community-acquired S. aureus bacteremias during 1980-

  9. Recurrent Escherichia coli bacteremia.

    OpenAIRE

    Maslow, J.N.; Mulligan, M E; Arbeit, R D

    1994-01-01

    Escherichia coli is the most common gram-negative organism associated with bacteremia. While recurrent E. coli urinary tract infections are well-described, recurrent E. coli bacteremia appears to be uncommon, with no episodes noted in multiple series of patients with gram-negative bacteremias. We report on 5 patients with recurrent bloodstream infections identified from a series of 163 patients with E. coli bacteremia. For each patient, the isolates from each episode were analyzed by pulsed-f...

  10. Anti-staphylococcal humoral immune response in persistent nasal carriers and noncarriers of Staphylococcus aureus

    NARCIS (Netherlands)

    N.J. Verkaik (Nelianne); C.P. de Vogel (Corné); H.A.M. Boelens (Hélène); D. Grumann (Dorothee); T. Hoogenboezem (Theo); C. Vink (Cornelis); H. Hooijkaas (Herbert); T.J. Foster (Timothy); H.A. Verbrugh (Henri); A.F. van Belkum (Alex); W.J.B. van Wamel (Willem)

    2009-01-01

    textabstractBACKGROUND. Persistent carriers have a higher risk of Staphylococcus aureus infections than noncarriers but a lower risk of bacteremia-related death. Here, the role played by anti-staphylococcal antibodies was studied. METHODS. Serum samples from 15 persistent carriers and 19 noncarriers

  11. Nitric oxide mediated Staphylococcus aureus pathogenesis and protective role of nanoconjugated vancomycin

    Institute of Scientific and Technical Information of China (English)

    Subhankari Prasad Chakraborty; Santanu Kar Mahapatra; Sumanta Kumar Sahu; Sourav Chattopadhyay; Panchanan Pramanik; Somenath Roy

    2011-01-01

    Objective:To test the survival ofStaphylococcus aureus (S. aureus) inside lymphocyte that contributes to the pathogenesis of infection and possible anti-inflammatory and antioxidative effect of nanoconjugated vancomycin againstin vivo S. aureus infection in a dose and duration dependent manner.Methods:5×106CFU/mL vancomycin-sensitive S. aureus(VSSA) and vancomycin-resistiveS. aureus (VRSA) were challenged in Swiss male mice for3 days,5 days, 10 days and15days, respectively. Bacteremia and inflammatory parameters were observed to evaluate the duration for development ofVSSA andVRSA infection.100mg/kg bw/day and500 mg/kg bw/day nanoconjugated vancomycin were administrated toVSSA andVRSA infected group for5days. Bacteremia, inflammatory parameters and oxidative stress related parameters were tested to observe the effective dose of nanoconjugated vancomycin againstVSSAandVRSA infection. Nanoconjugated vancomycin was treated at a dose of100 mg/kg bw/day and500 mg/kg bw/day, respectively, toVSSA andVRSA infected group for successive5 days,10 days and 15 days. Bacteremia, inflammatory parameters and oxidative stress related parameters were observed to assess the effective duration of nanoconjugated vancomycin againstVSSAand VRSA infection.Results: The result revealed thatin vivoVSSA andVRSA infection developed after 5 days of challenge by elevating theNO generation in lymphocyte and serum inflammatory markers. Administration with nanoconjugated vancomycin toVSSA andVRSA infected group at a dose of100 mg/kg bw/day and500 mg/kg bw/day, respectively, for successive10 days eliminated bacterimia, decreasedNO generation in lymphocyte, serum inflammatory markers and increased antioxidant enzyme status.Conclusions:These findings suggest,in vivochallenge ofVSSA andVRSA for5 days can produce the highest degree of damage in lymphocyte which can be ameliorated by treatment with nanoconjugated vancomycin for10 successive days.

  12. Impact of Vancomycin on sarA-Mediated Biofilm Formation: Role in Persistent Endovascular Infections Due to Methicillin-Resistant Staphylococcus aureus

    OpenAIRE

    Abdelhady, W; Bayer, A S; Seidl, K; Moormeier, D E; Bayles, K W; Cheung, A.; Yeaman, M R; Xiong, Y Q

    2014-01-01

    Background. Staphylococcus aureus is the most common cause of endovascular infections. The staphylococcal accessory regulator A locus (sarA) is a major virulence determinant that may potentially impact methicillin-resistant S. aureus (MRSA) persistence in such infections via its influence on biofilm formation. Methods. Two healthcare-associated MRSA isolates from patients with persistent bacteremia and 2 prototypical community-acquired MRSA strains, as well as their respective isogenic sar...

  13. Fibrinogen acts as a bridging molecule in the adherence of Staphylococcus aureus to cultured human endothelial cells.

    OpenAIRE

    Cheung, A L; Krishnan, M.; Jaffe, E A; Fischetti, V A

    1991-01-01

    The propensity of Staphylococcus aureus to cause acute endovascular infections during transient bacteremia is poorly understood. To examine the events leading to the attachment of staphylococci to endothelium, adherence assays were developed to study the role of blood factors in the mediation of staphylococcal adherence to cultured human umbilical vein endothelium in vitro. Results indicate that the preferential attachment of S. aureus to endothelial cells is mediated by fibrinogen adsorbed f...

  14. Effects of vancomycin versus nafcillin in enhancing killing of methicillin-susceptible Staphylococcus aureus causing bacteremia by human cathelicidin LL-37.

    Science.gov (United States)

    Le, J; Dam, Q; Schweizer, M; Thienphrapa, W; Nizet, V; Sakoulas, G

    2016-09-01

    Recent studies have demonstrated that anti-staphylococcal beta-lactam antibiotics, like nafcillin, render methicillin-resistant Staphylococcus aureus (MRSA) more susceptible to killing by innate host defense peptides (HDPs), such as cathelicidin LL-37. We compared the effects of growth in 1/4 minimum inhibitory concentration (MIC) of nafcillin or vancomycin on the LL-37 killing of 92 methicillin-susceptible S. aureus (MSSA) isolates. For three randomly selected strains among these, we examined the effects of nafcillin, vancomycin, daptomycin, or linezolid on LL-37 killing and autolysis. Growth in the presence of subinhibitory nafcillin significantly enhanced LL-37 killing of MSSA compared to vancomycin and antibiotic-free controls. Nafcillin also reduced MSSA production of the golden staphylococcal pigment staphyloxanthin in 39 % of pigmented strains vs. 14 % for vancomycin. Among the antibiotics tested, only nafcillin resulted in significantly increased MSSA autolysis. These studies point to additional mechanisms of anti-staphylococcal activity of nafcillin beyond direct bactericidal activity, properties that vancomycin and other antibiotic classes do not exhibit. The ability of nafcillin to enhance sensitivity to innate HDPs may contribute to its superior effectiveness against MSSA, as suggested by studies comparing clinical outcomes to vancomycin treatment. PMID:27234592

  15. Role of GapC in the pathogenesis of Staphylococcus aureus.

    Science.gov (United States)

    Kerro-Dego, Oudessa; Prysliak, Tracy; Perez-Casal, Jose; Potter, Andrew A

    2012-05-01

    Staphylococcus aureus is recognized worldwide as a major pathogen causing clinical or subclinical intramammary infections in lactating cows, sheep and goats. S. aureus produces a wide arsenal of cell surface and extracellular proteins involved in virulence. Among these are two conserved proteins with glyceraldehyde-3-phosphate dehydrogenase (GAPDH) activity named glyceraldehyde-3-phosphate dehydrogenase-B (GapB) and -C (GapC). In this study, we used the S. aureus wild type strain RN6390 and its isogenic gapC mutant H330 in in vitro and in vivo studies and determined that the S. aureus GapC protein plays a role on adherence to and internalization into bovine mammary epithelial (MAC-T) cells. In addition, we found that S. aureus H330 did not caused mastitis after an experimental infection of ovine mammary glands. Together, these results show that GapC is important in the pathogenesis of S. aureus mastitis. PMID:22176759

  16. Mortality and hospital stay associated with resistant Staphylococcus aureus and Escherichia coli bacteremia: estimating the burden of antibiotic resistance in Europe.

    Directory of Open Access Journals (Sweden)

    Marlieke E A de Kraker

    2011-10-01

    Full Text Available BACKGROUND: The relative importance of human diseases is conventionally assessed by cause-specific mortality, morbidity, and economic impact. Current estimates for infections caused by antibiotic-resistant bacteria are not sufficiently supported by quantitative empirical data. This study determined the excess number of deaths, bed-days, and hospital costs associated with blood stream infections (BSIs caused by methicillin-resistant Staphylococcus aureus (MRSA and third-generation cephalosporin-resistant Escherichia coli (G3CREC in 31 countries that participated in the European Antimicrobial Resistance Surveillance System (EARSS. METHODS AND FINDINGS: The number of BSIs caused by MRSA and G3CREC was extrapolated from EARSS prevalence data and national health care statistics. Prospective cohort studies, carried out in hospitals participating in EARSS in 2007, provided the parameters for estimating the excess 30-d mortality and hospital stay associated with BSIs caused by either MRSA or G3CREC. Hospital expenditure was derived from a publicly available cost model. Trends established by EARSS were used to determine the trajectories for MRSA and G3CREC prevalence until 2015. In 2007, 27,711 episodes of MRSA BSIs were associated with 5,503 excess deaths and 255,683 excess hospital days in the participating countries, whereas 15,183 episodes of G3CREC BSIs were associated with 2,712 excess deaths and 120,065 extra hospital days. The total costs attributable to excess hospital stays for MRSA and G3CREC BSIs were 44.0 and 18.1 million Euros (63.1 and 29.7 million international dollars, respectively. Based on prevailing trends, the number of BSIs caused by G3CREC is likely to rapidly increase, outnumbering the number of MRSA BSIs in the near future. CONCLUSIONS: Excess mortality associated with BSIs caused by MRSA and G3CREC is significant, and the prolongation of hospital stay imposes a considerable burden on health care systems. A foreseeable shift in

  17. Impact of bacteremia on the pathogenesis of experimental pneumococcal meningitis

    DEFF Research Database (Denmark)

    Brandt, C.T.; Holm, D.; Liptrot, Matthew George;

    2008-01-01

    Background. Bacteremia plays a major role in the outcome of pneumococcal meningitis. This experimental study investigated how bacteremia influences the pathophysiologic profile of the brain. Methods. Rats with Streptococcus pneumoniae meningitis were randomized to 1 of 3 groups of infected study ...

  18. Francisella tularensis Bacteremia

    Science.gov (United States)

    Haristoy, X.; Lozniewski, A.; Tram, C.; Simeon, D.; Bevanger, L.; Lion, C.

    2003-01-01

    Bacteremia caused by Francisella tularensis is rare and has been reported mainly in the United States and infrequently in Europe. We report herein the first case of bacteremic F. tularensis pneumonia in an immunocompetent individual in southern Europe. PMID:12791928

  19. Recurrent Escherichia coli bacteremia.

    Science.gov (United States)

    Maslow, J N; Mulligan, M E; Arbeit, R D

    1994-01-01

    Escherichia coli is the most common gram-negative organism associated with bacteremia. While recurrent E. coli urinary tract infections are well-described, recurrent E. coli bacteremia appears to be uncommon, with no episodes noted in multiple series of patients with gram-negative bacteremias. We report on 5 patients with recurrent bloodstream infections identified from a series of 163 patients with E. coli bacteremia. For each patient, the isolates from each episode were analyzed by pulsed-field gel electrophoresis (PFGE) and ribotyping and for the presence of E. coli virulence factors. For each of four patients, the index and recurrent episodes of bacteremia represented the same strain as defined by PFGE, and the strains were found to carry one or more virulence factors. The remaining patient, with two episodes of bloodstream infection separated by a 4-year interval, was infected with two isolates that did not carry any virulence factors and that were clonally related by ribotype analysis but differed by PFGE. All five patients had either a local host defense defect (three patients) or impaired systemic defenses (one patient) or both (one patient). Thus, recurrent E. coli bacteremia is likely to represent a multifactorial process that occurs in patients with impaired host defenses who are infected with virulent isolates. Images PMID:7910828

  20. Secretome Analysis Defines the Major Role of SecDF in Staphylococcus aureus Virulence

    OpenAIRE

    Chantal Quiblier; Kati Seidl; Bernd Roschitzki; Zinkernagel, Annelies S.; Brigitte Berger-Bächi; Senn, Maria M.

    2013-01-01

    The Sec pathway plays a prominent role in protein export and membrane insertion, including the secretion of major bacterial virulence determinants. The accessory Sec constituent SecDF has been proposed to contribute to protein export. Deletion of Staphylococcus aureus secDF has previously been shown to reduce resistance, to alter cell separation, and to change the expression of certain virulence factors. To analyse the impact of the secDF deletion in S. aureus on protein secretion, a quantita...

  1. Dietzia papillomatosis Bacteremia

    DEFF Research Database (Denmark)

    Rammer, Paul; Calum, Henrik; Moser, Claus;

    2013-01-01

    The clinical significance of Dietzia papillomatosis is for the moment limited to the rare skin disease confluent and reticulated papillomatosis. We present a case of infection with D. papillomatosis in a 2-year-old boy with known syringomyelia. The microbiological diagnosis was done using 16S rRN......RNA gene sequencing. This is the first report of bacteremia with D. papillomatosis....

  2. Staphylococcus aureus Toxins and Diabetic Foot Ulcers: Role in Pathogenesis and Interest in Diagnosis

    Directory of Open Access Journals (Sweden)

    Catherine Dunyach-Remy

    2016-07-01

    Full Text Available Infection of foot ulcers is a common, often severe and costly complication in diabetes. Diabetic foot infections (DFI are mainly polymicrobial, and Staphylococcus aureus is the most frequent pathogen isolated. The numerous virulence factors and toxins produced by S. aureus during an infection are well characterized. However, some particular features could be observed in DFI. The aim of this review is to describe the role of S. aureus in DFI and the implication of its toxins in the establishment of the infection. Studies on this issue have helped to distinguish two S. aureus populations in DFI: toxinogenic S. aureus strains (harboring exfoliatin-, EDIN-, PVL- or TSST-encoding genes and non-toxinogenic strains. Toxinogenic strains are often present in infections with a more severe grade and systemic impact, whereas non-toxinogenic strains seem to remain localized in deep structures and bone involving diabetic foot osteomyelitis. Testing the virulence profile of bacteria seems to be a promising way to predict the behavior of S. aureus in the chronic wounds.

  3. The incidence and prognosis of patients with bacteremia.

    Science.gov (United States)

    Nielsen, Stig Lønberg

    2015-07-01

    incidence rates decreased for Escherichia coli, Staphylococcus aureus, co-agulase-negative staphylococci and Streptococcus pneumoniae, and increased for Pseudomonas aeruginosa and enterococci species (pincidence of 14.2 per 1000 admissions and 23.6 per 10,000 bed days; highest for males, elderly individuals (> 65 years), and patients initially admitted to the Departments of Hematology, Nephrology, Internal Medicine, Urology or Oncology. The daily incidence was highest on the day of admission and declined rapidly to a low level on Day 3-7. Hereafter it increased steadily until Day 12 followed by more or less constant daily incidences. The daily incidences varied considerably with patient and clinical characteristics. Study III: In a population-based cohort study, we included 7783 patients with first-time bacteremia and 38,906 population controls matched on sex, year of birth and residency. We found that the cumulative mortality in bacteremia patients and population controls was 22.0% vs. 0.2% (30 days), 41.4% vs. 2.6% (1 year), and 75.8% vs. 36.6% (10 years). Bacteremia patients were consistently at increased risk of death compared with population controls throughout 12 years of follow-up and the risk of death remained 2-fold increased even among 5-year survivors of bacteremia (adjusted MRR: 2.1; 95% CI: 1.8-2.3). The most common causes of death after bacteremia were cancer and cardiovascular diseases. Compared with population controls, bacteremia patients were at the highest risk of death from genitourinary diseases and infectious diseases within 1 year of bacteremia. Among 1-year survivors of bacteremia, the risk of death was increased for all major causes of death compared with population controls. We conclude that the occurrence of bacteremia is decreasing in the general population. However, bacteremia is associated with a very poor short- and long-term prognosis and the risk of death remains increased for years compared with the general population. The most common

  4. Comparative Study of Plasma Endotoxin with Procalcitonin Levels in Diagnosis of Bacteremia in Intensive Care Unit Patients

    OpenAIRE

    Tao Wang; Yun-Liang Cui; Zhao-Fen Lin; De-Chang Chen

    2016-01-01

    Background: Both procalcitonin (PCT) and plasma endotoxin levels cannot be solely used for a definite diagnosis of bacteremia or sepsis, and there has been few study comparing the values of the two biomarkers for the diagnosis of bacteremia. The aim of this study was to identify bacteria causing bacteremia and evaluate the role of the two biomarkers in the diagnosis of bacteremia in Intensive Care Unit (ICU). Methods: The medical records of 420 patients in ICU were retrospectively reviewed...

  5. Comparative Study of Plasma Endotoxin with Procalcitonin Levels in Diagnosis of Bacteremia in Intensive Care Unit Patients

    OpenAIRE

    WANG, Tao; Cui, Yun-Liang; Lin, Zhao-fen; Chen, De-Chang

    2016-01-01

    Background: Both procalcitonin (PCT) and plasma endotoxin levels cannot be solely used for a definite diagnosis of bacteremia or sepsis, and there has been few study comparing the values of the two biomarkers for the diagnosis of bacteremia. The aim of this study was to identify bacteria causing bacteremia and evaluate the role of the two biomarkers in the diagnosis of bacteremia in Intensive Care Unit (ICU). Methods: The medical records of 420 patients in ICU were retrospectively reviewed. P...

  6. Decreasing incidence rates of bacteremia

    DEFF Research Database (Denmark)

    Nielsen, Stig Lønberg; Pedersen, C; Jensen, T G;

    2014-01-01

    BACKGROUND: Numerous studies have shown that the incidence rate of bacteremia has been increasing over time. However, few studies have distinguished between community-acquired, healthcare-associated and nosocomial bacteremia. METHODS: We conducted a population-based study among adults with first......-acquired, 50.0 for healthcare-associated and 66.7 for nosocomial bacteremia. During 2000-2008, the overall incidence rate decreased by 23.3% from 254.1 to 198.8 (3.3% annually, p ...) and the incidence rate of nosocomial bacteremia decreased by 28.9% from 82.2 to 56.0 (4.2% annually, p

  7. Genetic Screen Reveals the Role of Purine Metabolism in Staphylococcus aureus Persistence to Rifampicin

    Directory of Open Access Journals (Sweden)

    Rebecca Yee

    2015-12-01

    Full Text Available Chronic infections with Staphylococcus aureus such as septicemia, osteomyelitis, endocarditis, and biofilm infections are difficult to treat because of persisters. Despite many efforts in understanding bacterial persistence, the mechanisms of persister formation in S. aureus remain elusive. Here, we performed a genome-wide screen of a transposon mutant library to study the molecular mechanisms involved in persistence of community-acquired S. aureus. Screening of the library for mutants defective in persistence or tolerance to rifampicin revealed many genes involved in metabolic pathways that are important for antibiotic persistence. In particular, the identified mutants belonged to metabolic pathways involved in carbohydrate, amino acid, lipid, vitamin and purine biosynthesis. Five mutants played a role in purine biosynthesis and two mutants, purB, an adenylosuccinate lyase, and purM, a phosphoribosylaminoimidazole synthetase, were selected for further confirmation. Mutants purB and purM showed defective persistence compared to the parental strain USA300 in multiple stress conditions including various antibiotics, low pH, and heat stress. The defect in persistence was restored by complementation with the wildtype purB and purM gene in the respective mutants. These findings provide new insights into the mechanisms of persistence in S. aureus and provide novel therapeutic targets for developing more effective treatment for persistent infections due to S. aureus.

  8. Helicobacter Pylori Bacteremia: An Unusual Finding

    Science.gov (United States)

    De Luca, Concetta; Mancin, Annalisa; Calabrò, Maria; Daleno, Cristina; Ferrario, Antonella; Renzulli, Raffaella; Scuderi, Cristina; Casari, Erminia

    2016-01-01

    We report a case of Helicobacter pylori transient bacteremia in a woman with ulcerated antral gastric cancer. The patient was hospitalized for laparoscopy and subtotal gastrectomy. After surgery she developed fever (39°C) and was empirically treated with levofloxacin. Blood cultures, collected and sent immediately to Laboratory, were positive for a spiral Gram-negative bacterium. This isolate was identified as H. pylori and the specific susceptibility test was performed. One day after the fever was decreased but antibiotic treatment with levofloxacin was continued and it was maintained until discharge. In summary, H. pylori transient bacteremia may occur as a rare complication after stomach surgery. Further studies are necessary to elucidate the potential role of Helicobacter pylori presence in blood.

  9. Dissecting the role of ADAM10 as a mediator of Staphylococcus aureus α-toxin action.

    Science.gov (United States)

    von Hoven, Gisela; Rivas, Amable J; Neukirch, Claudia; Klein, Stefan; Hamm, Christian; Qin, Qianqian; Meyenburg, Martina; Füser, Sabine; Saftig, Paul; Hellmann, Nadja; Postina, Rolf; Husmann, Matthias

    2016-07-01

    Staphylococcus aureus is a leading cause of bacterial infections in humans, including life-threatening diseases such as pneumonia and sepsis. Its small membrane-pore-forming α-toxin is considered an important virulence factor. By destroying cell-cell contacts through cleavage of cadherins, the metalloproteinase ADAM10 (a disintegrin and metalloproteinase 10) critically contributes to α-toxin-dependent pathology of experimental S. aureus infections in mice. Moreover, ADAM10 was proposed to be a receptor for α-toxin. However, it is unclear whether the catalytic activity or specific domains of ADAM10 are involved in mediating binding and/or subsequent cytotoxicity of α-toxin. Also, it is not known how α-toxin triggers ADAM10's enzymatic activity, and whether ADAM10 is invariably required for all α-toxin action on cells. In the present study, we show that efficient cleavage of the ADAM10 substrate epithelial cadherin (E-cadherin) requires supra-cytotoxic concentrations of α-toxin, leading to significant increases in intracellular [Ca(2+)]; the fall in cellular ATP levels, typically following membrane perforation, became observable at far lower concentrations. Surprisingly, ADAM10 was dispensable for α-toxin-dependent xenophagic targeting of S. aureus, whereas a role for α-toxin attack on the plasma membrane was confirmed. The catalytic site of ADAM10, furin cleavage site, cysteine switch and intracellular domain of ADAM10 were not required for α-toxin binding and subsequent cytotoxicity. In contrast, an essential role for the disintegrin domain and the prodomain emerged. Thus, co-expression of the prodomain with prodomain-deficient ADAM10 reconstituted binding of α-toxin and susceptibility of ADAM10-deficient cells. The results of the present study may help to inform structural analyses of α-toxin-ADAM10 interactions and to design novel strategies to counteract S. aureus α-toxin action.

  10. Bacteremia in Children Hospitalized with Respiratory Syncytial Virus Infection

    Science.gov (United States)

    Pardo-Seco, Jacobo; Gómez-Carballa, Alberto; Martinón-Torres, Nazareth; Martinón-Sánchez, José María; Justicia-Grande, Antonio; Rivero-Calle, Irene; Pinnock, Elli; Salas, Antonio; Fink, Colin

    2016-01-01

    Background The risk of bacteremia is considered low in children with acute bronchiolitis. However the rate of occult bacteremia in infants with RSV infection is not well established. The aim was to determine the actual rate and predictive factors of bacteremia in children admitted to hospital due to confirmed RSV acute respiratory illness (ARI), using both conventional culture and molecular techniques. Methods A prospective multicenter study (GENDRES-network) was conducted between 2011–2013 in children under the age of two admitted to hospital because of an ARI. Among those RSV-positive, bacterial presence in blood was assessed using PCR for Meningococcus, Streptococcus pneumoniae, Haemophilus influenzae, Streptococcus pyogenes, Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus, in addition to conventional cultures. Results 66 children with positive RSV respiratory illness were included. In 10.6% patients, bacterial presence was detected: H. influenzae (n = 4) and S. pneumoniae (n = 2). In those patients with bacteremia, there was a previous suspicion of bacterial superinfection and had received empirical antibiotic treatment 6 out of 7 (85.7%) patients. There were significant differences in terms of severity between children with positive bacterial PCR and those with negative results: PICU admission (100% vs. 50%, P-value = 0.015); respiratory support necessity (100% vs. 18.6%, P-value < 0.001); Wood-Downes score (mean = 8.7 vs. 4.8 points, P-value < 0.001); GENVIP scale (mean = 17 vs. 10.1, P-value < 0.001); and length of hospitalization (mean = 12.1 vs. 7.5 days, P-value = 0.007). Conclusion Bacteremia is not frequent in infants hospitalized with RSV respiratory infection, however, it should be considered in the most severe cases. PMID:26872131

  11. Reassessing the Role of Staphylococcus aureus Clumping Factor and Fibronectin-Binding Protein by Expression in Lactococcus lactis

    OpenAIRE

    Que, Yok-Ai; François, Patrice; Haefliger, Jacques-Antoine; Entenza, José-Manuel; Vaudaux, Pierre; Moreillon, Philippe

    2001-01-01

    Since Staphylococcus aureus expresses multiple pathogenic factors, studying their individual roles in single-gene-knockout mutants is difficult. To circumvent this problem, S. aureus clumping factor A (clfA) and fibronectin-binding protein A (fnbA) genes were constitutively expressed in poorly pathogenic Lactococcus lactis using the recently described pOri23 vector. The recombinant organisms were tested in vitro for their adherence to immobilized fibrinogen and fibronectin and in vivo for the...

  12. Infection and T lymphocyte subpopulations: changes associated with bacteremia and the acquired immunodeficiency syndrome.

    Science.gov (United States)

    Fishman, J A; Martell, K M; Rubin, R H

    1983-01-01

    Patients with bacteremia, bacterial endocarditis, or acquired immunodeficiency syndrome (AIDS) were prospectively studied using monoclonal antibody reagents to assess alterations in T-lymphocyte subpopulations. Patients with endocarditis had significantly higher ratios of T-helper (OKT4+) to T-suppressor-cytotoxic (OKT8+) cells than did patients with bacteremia alone. Staphylococcus aureus endocarditis patients had a mean ratio of 8.49 (range 4.73-22.36) while S aureus bacteremia had a mean ratio of 2.75 (range 2.15 to 3.21). Similar results were found with Staphylococcus epidermidis endocarditis (mean 1.62) and bacteremia (mean 1.23). Klebsiella pneumoniae endocarditis (5.10) and sepsis (4.32), and E coli bacteremia (2.15). Nine male patients with AIDS had markedly depressed ratios (mean 0.25, range 0.04 to 0.67) while eight male homosexuals with unexplained lymphadenopathy ("pre-AIDS") had normal or increased ratios. Bacteremic infections are associated with an increased OKT4+/OKT8+ ratio with the degree of increase dependent upon virulence, location, and duration of infection. The immunomodulating effects of infection are manifested in changes in T-cell subsets, and these measurements can be useful in clinical management. PMID:6094086

  13. Bacteremia causes hippocampal apoptosis in experimental pneumococcal meningitis

    DEFF Research Database (Denmark)

    Andersen, Christian Østergaard; Leib, S.L.; Rowland, Ian J;

    2010-01-01

    -specific pneumococcal antibodies (n=14), and III. uninfected controls (n=6). RESULTS: Pneumococcal meningitis resulted in a significantly higher apoptosis score 0.22 (0.18-0.35) compared to uninfected controls (0.02 (0.00-0.02), Mann Whitney test, P=0.0003). Also, meningitis with an attenuation of bacteremia...... by antibody treatment resulted in significantly reduced apoptosis (0.08 (0.02-0.20), P=0.01) as compared to meningitis. CONCLUSIONS: Our results demonstrate that bacteremia accompanying meningitis plays an important role in the development of hippocampal injury in pneumococcal meningitis....

  14. A regulatory role for Staphylococcus aureus toxin-antitoxin system PemIKSa.

    Science.gov (United States)

    Bukowski, Michal; Lyzen, Robert; Helbin, Weronika M; Bonar, Emilia; Szalewska-Palasz, Agnieszka; Wegrzyn, Grzegorz; Dubin, Grzegorz; Dubin, Adam; Wladyka, Benedykt

    2013-01-01

    Toxin-antitoxin systems were shown to be involved in plasmid maintenance when they were initially discovered, but other roles have been demonstrated since. Here we identify and characterize a novel toxin-antitoxin system (pemIKSa) located on Staphylococcus aureus plasmid pCH91. The toxin (PemKSa) is a sequence-specific endoribonuclease recognizing the tetrad sequence U↓AUU, and the antitoxin (PemISa) inhibits toxin activity by physical interaction. Although the toxin-antitoxin system is responsible for stable plasmid maintenance our data suggest the participation of pemIKSa in global regulation of staphylococcal virulence by alteration of the translation of large pools of genes. We propose a common mechanism of reversible activation of toxin-antitoxin systems based on antitoxin transcript resistance to toxin cleavage. Elucidation of this mechanism is particularly interesting because reversible activation is a prerequisite for the proposed general regulatory role of toxin-antitoxin systems.

  15. Antibody responses in patients with invasive Staphylococcus aureus infections

    OpenAIRE

    Jacobsson, G; Colque-Navarro, P.; Gustafsson, E.; Andersson, R.; Möllby, R

    2010-01-01

    Abstract Correlation between antibody response and clinical outcome in Staphylococcus aureus bacteremia has yielded conflicting results. Immunization schedules have failed in clinical trials. Is the humoral response toward S. aureus of protective nature? A prospective study was performed in patients with invasive S. aureus (ISA) infections during the period 2003?2005. The antibody levels were determined at the beginning and at the end of treatment and one month later (n?=?96, n?=?7...

  16. Staphylococcus aureus-Fibronectin Interactions with and without Fibronectin-Binding Proteins and Their Role in Adhesion and Desorption

    NARCIS (Netherlands)

    Xu, C.P.; Boks, N.P.; Vries, de J.; Kaper, H.J.; Norde, W.; Busscher, H.J.; Mei, van der H.C.

    2008-01-01

    Adhesion and residence-time-dependent desorption of two Staphylococcus aureus strains with and without fibronectin (Fn) binding proteins (FnBPs) on Fn-coated glass were compared under flow conditions. To obtain a better understanding of the role of Fn-FnBP binding, the adsorption enthalpies of Fn wi

  17. Staphylococcus aureus-fibronectin interactions with and without fibronectin-binding proteins and their role in adhesion and desorption

    NARCIS (Netherlands)

    Xu, Chun; Boks, Niels P; de Vries, Jacob; Kaper, Harm; Norde, Willem; Busscher, Hendrik; van der Mei, Henderina

    2008-01-01

    Adhesion and residence-time-dependent desorption of two Staphylococcus aureus strains with and without fibronectin (Fn) binding proteins (FnBPs) on Fn-coated glass were compared under flow conditions. To obtain a better understanding of the role of Fn-FnBP binding, the adsorption enthalpies of Fn wi

  18. The role of staphylothrombin-mediated fibrin deposition in catheter-related Staphylococcus aureus infections.

    Science.gov (United States)

    Vanassche, Thomas; Peetermans, Marijke; Van Aelst, Lucas N L; Peetermans, Willy E; Verhaegen, Jan; Missiakas, Dominique M; Schneewind, Olaf; Hoylaerts, Marc F; Verhamme, Peter

    2013-07-01

    Staphylococcus aureus (S. aureus) is a frequent cause of catheter-related infections. S. aureus secretes the coagulases staphylocoagulase and von Willebrand factor-binding protein, both of which form a staphylothrombin complex upon binding to prothrombin. Although fibrinogen and fibrin facilitate the adhesion of S. aureus to catheters, the contribution of staphylothrombin-mediated fibrin has not been examined. In this study, we use a S. aureus mutant lacking both coagulases (Δcoa/vwb) and dabigatran, a pharmacological inhibitor of both staphylothrombin and thrombin, to address this question. Genetic absence or chemical inhibition of pathogen-driven coagulation reduced both fibrin deposition and the retention of S. aureus on catheters in vitro. In a mouse model of jugular vein catheter infection, dabigatran reduced bacterial load on jugular vein catheters, as well as metastatic kidney infection. Importantly, inhibition of staphylothrombin improved the efficacy of vancomycin treatment both in vitro and in the mouse model. PMID:23532100

  19. Daptomycin-nonsusceptible, vancomycin-intermediate, methicillin-resistant Staphylococcus aureus endocarditis

    OpenAIRE

    Ryan Yu; Dale, Suzanne E; Deborah Yamamura; Vida Stankus; Christine Lee

    2012-01-01

    Due to the emergence of Staphylococcus aureus with reduced vancomycin susceptibility, newer antibiotics, including daptomycin, have been used to treat methicillin-resistant S aureus infections. Daptomycin is a cyclic lipopeptide that is approved to treat S aureus bacteremia and right-sided endocarditis, and reports of S aureus with reduced susceptibility to daptomycin are infrequent. To our knowledge, the present report describes the first Canadian case of daptomycin-nonsusceptible, vancomyci...

  20. Clostridium difficile Bacteremia, Taiwan1

    OpenAIRE

    Lee, Nan-Yao; Huang, Yu-Tsung; Hsueh, Po-Ren; Ko, Wen-Chien

    2010-01-01

    To determine clinical characteristics and outcome of patients with Clostridium difficile bacteremia (CDB), we identified 12 patients with CDB in 2 medical centers in Taiwan; all had underlying systemic diseases. Five had gastrointestinal diseases or conditions, including pseudomembranous colitis (2 patients); 4 recalled diarrhea, but only 5 had recent exposure to antimicrobial drugs. Ten available isolates were susceptible to metronidazole and vancomycin. Five isolates had C. difficile toxin ...

  1. Key role for clumping factor B in Staphylococcus aureus nasal colonization of humans

    NARCIS (Netherlands)

    H.F.L. Wertheim (Heiman); E.J. Walsh (Evelyn); R.S.R. Choudhurry (Roos); D.C. Melles (Damian); H.A.M. Boelens (Hélène); H. Miajlovic (Helen); H.A. Verbrugh (Henri); T.J. Foster (Timothy); A.F. van Belkum (Alex)

    2008-01-01

    textabstractBACKGROUND: Staphylococcus aureus permanently colonizes the vestibulum nasi of one-fifth of the human population, which is a risk factor for autoinfection. The precise mechanisms whereby S. aureus colonizes the nose are still unknown. The staphylococcal cell-wall protein clumping factor

  2. The role of human innate immune factors in nasal colonization by Staphylococcus aureus

    NARCIS (Netherlands)

    van Belkum, Alex; Emonts, Marieke; Wertheim, Heiman; Bartels, Hans; Cole, Alexander; Lemmens-den Toom, Nicole; Snijders, Susan Susan; Verbrugh, Henri; van Leeuwen, Willem

    2007-01-01

    Slaphylococcus aureus colonization of the human nares predisposes to sometimes severe auto-infection. To investigate whether genetic polymorphism affects the S. aureus carriage status, sequence variation in alpha-defensin and beta-defensin, and mannose-binding lectin (MBL) genes were determined for

  3. Comparative Study of Plasma Endotoxin with Procalcitonin Levels in Diagnosis of Bacteremia in Intensive Care Unit Patients

    Science.gov (United States)

    Wang, Tao; Cui, Yun-Liang; Lin, Zhao-Fen; Chen, De-Chang

    2016-01-01

    Background: Both procalcitonin (PCT) and plasma endotoxin levels cannot be solely used for a definite diagnosis of bacteremia or sepsis, and there has been few study comparing the values of the two biomarkers for the diagnosis of bacteremia. The aim of this study was to identify bacteria causing bacteremia and evaluate the role of the two biomarkers in the diagnosis of bacteremia in Intensive Care Unit (ICU). Methods: The medical records of 420 patients in ICU were retrospectively reviewed. Patients (n = 241) who met the inclusion criteria were subjected to blood culture (BC) for the analysis of the endotoxin or PCT levels. The exclusion criteria included the presence of infection with human immunodeficiency virus and/or AIDS, neutropenia without sepsis, pregnancy, treatment with immunosuppressive therapies, or blood diseases such as hematological tumors. Patients’ BC episodes were divided into BC negative, Gram-negative (GN) bacteria, Gram-positive bacteria, and fungi groups. The PCT and plasma endotoxin levels were compared in the different groups. Results: A total of 241 patients with 505 episodes of BC were analyzed. The GN bacteria group showed higher levels of PCT and endotoxin than the BC negative, Gram-positive bacteria, and fungi groups. GN bacteremia was more prevalent than Gram-positive bacteremia. The GN bacteremia caused by non-Enterobacteriaceae infection presented higher endotoxin level than that by Enterobacteriaceae, but no significant difference in PCT levels was observed between the two groups. The plasma endotoxin significantly differed among different groups and was bacterial species dependent. Conclusions: Plasma endotoxin was more related to GN than to Gram-positive bacteremia, and that endotoxin level was species dependent, but PCT level remained relatively more stable within the GN bacteria caused bacteremia. Both GN and positive bacteria caused bacteremia in the ICU patients in different regions of China. And PCT is a more valuable

  4. Cost Attributable to Nosocomial Bacteremia. Analysis According to Microorganism and Antimicrobial Sensitivity in a University Hospital in Barcelona

    Science.gov (United States)

    Riu, Marta; Chiarello, Pietro; Terradas, Roser; Sala, Maria; Garcia-Alzorriz, Enric; Castells, Xavier; Grau, Santiago; Cots, Francesc

    2016-01-01

    Aim To calculate the incremental cost of nosocomial bacteremia caused by the most common organisms, classified by their antimicrobial susceptibility. Methods We selected patients who developed nosocomial bacteremia caused by Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, or Pseudomonas aeruginosa. These microorganisms were analyzed because of their high prevalence and they frequently present multidrug resistance. A control group consisted of patients classified within the same all-patient refined-diagnosis related group without bacteremia. Our hospital has an established cost accounting system (full-costing) that uses activity-based criteria to analyze cost distribution. A logistic regression model was fitted to estimate the probability of developing bacteremia for each admission (propensity score) and was used for propensity score matching adjustment. Subsequently, the propensity score was included in an econometric model to adjust the incremental cost of patients who developed bacteremia, as well as differences in this cost, depending on whether the microorganism was multidrug-resistant or multidrug-sensitive. Results A total of 571 admissions with bacteremia matched the inclusion criteria and 82,022 were included in the control group. The mean cost was € 25,891 for admissions with bacteremia and € 6,750 for those without bacteremia. The mean incremental cost was estimated at € 15,151 (CI, € 11,570 to € 18,733). Multidrug-resistant P. aeruginosa bacteremia had the highest mean incremental cost, € 44,709 (CI, € 34,559 to € 54,859). Antimicrobial-susceptible E. coli nosocomial bacteremia had the lowest mean incremental cost, € 10,481 (CI, € 8,752 to € 12,210). Despite their lower cost, episodes of antimicrobial-susceptible E. coli nosocomial bacteremia had a major impact due to their high frequency. Conclusions Adjustment of hospital cost according to the organism causing bacteremia and antibiotic sensitivity could improve

  5. Contribution of Panton-Valentine leukocidin in community-associated methicillin-resistant Staphylococcus aureus pathogenesis.

    Directory of Open Access Journals (Sweden)

    Binh An Diep

    Full Text Available Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA strains typically carry genes encoding Panton-Valentine leukocidin (PVL. We used wild-type parental and isogenic PVL-deletion (Delta pvl strains of USA300 (LAC and SF8300 and USA400 (MW2 to test whether PVL alters global gene regulatory networks and contributes to pathogenesis of bacteremia, a hallmark feature of invasive staphylococcal disease. Microarray and proteomic analyses revealed that PVL does not alter gene or protein expression, thereby demonstrating that any contribution of PVL to CA-MRSA pathogenesis is not mediated through interference of global gene regulatory networks. Inasmuch as a direct role for PVL in CA-MRSA pathogenesis remains to be determined, we developed a rabbit bacteremia model of CA-MRSA infection to evaluate the effects of PVL. Following experimental infection of rabbits, an animal species whose granulocytes are more sensitive to the effects of PVL compared with the mouse, we found a contribution of PVL to pathogenesis over the time course of bacteremia. At 24 and 48 hours post infection, PVL appears to play a modest, but measurable role in pathogenesis during the early stages of bacteremic seeding of the kidney, the target organ from which bacteria were not cleared. However, the early survival advantage of this USA300 strain conferred by PVL was lost by 72 hours post infection. These data are consistent with the clinical presentation of rapid-onset, fulminant infection that has been associated with PVL-positive CA-MRSA strains. Taken together, our data indicate a modest and transient positive effect of PVL in the acute phase of bacteremia, thereby providing evidence that PVL contributes to CA-MRSA pathogenesis.

  6. Immunological role of nasal staphylococcus aureus carriage in patients with persistent allergic rhinitis

    Directory of Open Access Journals (Sweden)

    Mohamed Yousif Atia

    2008-10-01

    Full Text Available Nasal carriage of staphylococcus aureus (S.aureus exerts immunomodulatory effect in patients with atopic dermatitis and it may contribute to airway inflammation and allergic response in patients with allergic rhinitis. We Aim to investigate the frequency of nasal S.aureus carriage in patients with persistent allergic rhinitis and its possible influence on their symptoms and immune markers. We chosed 20 non smoker patients with house dust mite (HDM allergy causing allergic rhinitis and 20 non smoker healthy subjects matched for age and sex. For all subjects rhinoscopy was done, skin prick test, nasal culture for S.aureus, nasal interleukin 4,nasal total IgE, serum total IgE and serum specific IgE(SSIgE for HDM. Nasal S.aureus was detected in 16/20 patients (80% and 5/20 (25% in healthy subjects with highly significant statistical difference plt0.01. Correlation of nasal staph.aureus count and different systemic and local immune markers revealed highly significant positive correlation between nasal S.aureus count and serum total IgE (r = 0.78, plt0.01 and significant positive correlation with SSIgE (HDM (r = 0.53, plt0.05, nasal total IgE (r = 0.39, plt0.05 and nasal IL-4 (r = 0.55, plt0.05. Nasal staph.aureus actively modulated the immune reaction in persistent allergic rhinitis patients by promoting local IgE production, so we recommend early detection and treatment of S.aureus carriage in patients

  7. Bacteremia and candidemia in hematological malignancies

    DEFF Research Database (Denmark)

    Hovgaard, D; Skinhøj, P; Bangsborg, Jette Marie;

    1988-01-01

    171 episodes of bacteremia and candidemia in 142 patients were recorded during the period 1981-1985 in patients with hematological malignancies. Overall mortality, within 1 week of onset of bacteremia, was 20%. Increased mortality was found in patients with poor disease-prognosis (39%), with gran...

  8. Bacteremia Caused by Group G Streptococci, Taiwan

    OpenAIRE

    Liao, Chun-Hsing; Liu, Liang-Chun; Huang, Yu-Tsung; Teng, Lee-Jeng; Hsueh, Po-Ren

    2008-01-01

    A retrospective observational study in Taiwan, 1998–2004, identified 92 patients with group G streptococcal bacteremia; 86 had Streptococcus dysgalactiae subspecies equisimilis. The most common diagnosis was cellulitis (48 cases), followed by primary bacteremia (34 cases). Infection recurred in 9 patients. Mortality rate was low (3.3%); resistance to quinupristin-dalfopristin was high.

  9. Staphylococcus aureus toxins.

    Science.gov (United States)

    Otto, Michael

    2014-02-01

    Staphylococcus aureus is a dangerous pathogen that causes a variety of severe diseases. The virulence of S. aureus is defined by a large repertoire of virulence factors, among which secreted toxins play a preeminent role. Many S. aureus toxins damage biological membranes, leading to cell death. In particular, S. aureus produces potent hemolysins and leukotoxins. Among the latter, some were recently identified to lyse neutrophils after ingestion, representing an especially powerful weapon against bacterial elimination by innate host defense. Furthermore, S. aureus secretes many factors that inhibit the complement cascade or prevent recognition by host defenses. Several further toxins add to this multi-faceted program of S. aureus to evade elimination in the host. This review will give an overview over S. aureus toxins focusing on recent advances in our understanding of how leukotoxins work in receptor-mediated or receptor-independent fashions.

  10. Regulation of Arachidonic Acid Pathway and Eosinophilic Inflammation in Chronic Rhinosinusitis/ Nasal Polyposis. Potential Role of Staphylococcus aureus Enterotoxins

    OpenAIRE

    Pérez Novo, C

    2006-01-01

    linked to inflammation. Furthermore, EP2 and EP4 receptor expression was increased in chronic rhinosinusitis and nasal polyp subjects in contrast to EP1 and EP3, which were down regulated in the polyp group, suggesting a distinctive role of these receptors in the pathophysiology of nasal polyposis. Finally, based on our previous findings and parallel work of our group, we studied the influence of S. aureus enterotoxins in the regulation of both eosinophilic inflammatory and eicosanoid pathway...

  11. Nosocomial Staphylococcus Aureus Bacterimia among Nasal Carriers of Methicillin- Resistant and Methicillin-Susceptible Strains

    NARCIS (Netherlands)

    M. Pujol (Miquel); C. Pena; R. Pallares (Roman); J. Ariza (Javier); J. Ayats (Josefina); M.A. Dominguez; F. Gudiol (Francesc)

    1996-01-01

    textabstractObjectives To determine the relevance of nasal carriage of Staphylococcus aureus, either methicillin-sensitive (MSSA) or methicillinresistant (MRSA), as a risk factor for the development of nosocomial S aureus bacteremia during an MRSA outbreak. patients and methods: In this prospective

  12. Bacteremia in burned patients admitted to Sina Hospital, Tabriz, Iran

    OpenAIRE

    Parviz Saleh; Hamid Noshad

    2014-01-01

    Introduction: One of the most important causes of mortality and morbidity in burn wards is infection, and it is the major reason of death in burn injuries. There are several reasons that make burn victims predisposed to infection. The current study aimed to investigate the role of different factors that have an effect on bacteremia occurrence in burn patients and factors which are relevant to mortality in these patients. Methods: This descriptive-analytic study conducted in a 1...

  13. Simplified risk stratification criteria for identification of patients with MRSA bacteremia at low risk of infective endocarditis: implications for avoiding routine transesophageal echocardiography in MRSA bacteremia.

    Science.gov (United States)

    Buitron de la Vega, P; Tandon, P; Qureshi, W; Nasr, Y; Jayaprakash, R; Arshad, S; Moreno, D; Jacobsen, G; Ananthasubramaniam, K; Ramesh, M; Zervos, M

    2016-02-01

    The aim of this study was to identify patients with methicillin-resistant Staphylococcus aureus (MRSA) bacteremia with low risk of infective endocarditis (IE) who might not require routine trans-esophageal echocardiography (TEE). We retrospectively evaluated 398 patients presenting with MRSA bacteremia for the presence of the following clinical criteria: intravenous drug abuse (IVDA), long-term catheter, prolonged bacteremia, intra-cardiac device, prosthetic valve, hemodialysis dependency, vertebral/nonvertebral osteomyelitis, cardio-structural abnormality. IE was diagnosed using the modified Duke criteria. Of 398 patients with MRSA bacteremia, 26.4 % of cases were community-acquired, 56.3 % were health-care-associated, and 17.3 % were hospital-acquired. Of the group, 44 patients had definite IE, 119 had possible IE, and 235 had a rejected diagnosis. Out of 398 patients, 231 were evaluated with transthoracic echocardiography (TTE) or TEE. All 44 patients with definite IE fulfilled at least one criterion (sensitivity 100 %). Finally, a receiver operator characteristic (ROC) curve was obtained to evaluate the total risk score of our proposed criteria as a predictor of the presence of IE, and this was compared to the ROC curve of a previously proposed criteria. The area under the ROC curve for our criteria was 0.710, while the area under the ROC curve for the criteria previously proposed was 0.537 (p < 0.001). The p-value for comparing those 2 areas was less than 0.001, indicating statistical significance. Patients with MRSA bacteremia without any of our proposed clinical criteria have very low risk of developing IE and may not require routine TEE. PMID:26676855

  14. Internalization of Staphylococcus aureus in Lymphocytes Induces Oxidative Stress and DNA Fragmentation: Possible Ameliorative Role of Nanoconjugated Vancomycin

    Directory of Open Access Journals (Sweden)

    Subhankari Prasad Chakraborty

    2011-01-01

    Full Text Available Staphylococcus aureus is the most frequently isolated pathogen causing bloodstream infections, skin and soft tissue infections and pneumonia. Lymphocyte is an important immune cell. The aim of the present paper was to test the ameliorative role of nanoconjugated vancomycin against Vancomycin-sensitive Staphylococcus aureus (VSSA and vancomycin-resistant Staphylococcus aureus (VRSA infection-induced oxidative stress in lymphocytes. VSSA and VRSA infections were developed in Swiss mice by intraperitoneal injection of 5×106 CFU/mL bacterial solutions. Nanoconjugated vancomycin was adminstrated to VSSA- and VRSA-infected mice at its effective dose for 10 days. Vancomycin was adminstrated to VSSA- and VRSA-infected mice at a similar dose, respectively, for 10 days. Vancomycin and nanoconjugated vancomycin were adminstrated to normal mice at their effective doses for 10 days. The result of this study reveals that in vivo VSSA and VRSA infection significantly increases the level of lipid peroxidation, protein oxidation, oxidized glutathione level, nitrite generation, nitrite release, and DNA damage and decreases the level of reduced glutathione, antioxidant enzyme status, and glutathione-dependent enzymes as compared to control group, which were increased or decreased significantly near to normal in nanoconjugated vancomycin-treated group. These findings suggest the potential use and beneficial role of nanoconjugated vancomycin against VSSA and VRSA infection-induced oxidative stress in lymphocytes.

  15. Role of acute graft-versus-host disease in the risk of bacteremia and invasive fungal disease after allogeneic hemopoietic stem cell transplantation in children. Results from a single-center observational study.

    Science.gov (United States)

    Castagnola, Elio; Bagnasco, Francesca; Bandettini, Roberto; Caviglia, Ilaria; Morreale, Giuseppe; Lanino, Edoardo; Giardino, Stefano; Moroni, Cristina; Haupt, Riccardo; Faraci, Maura

    2014-07-01

    Data on epidemiology of severe infectious complications, ie, bacteremia or invasive fungal disease (IFD), in children with acute graft-versus-host disease (aGVHD) after allogeneic hemopoietic stem cell transplantation (HSCT) are scarce. In a retrospective, single-center study, we analyzed the risk (hazard ratio [HR]) and the rate (episodes/1000 patients days at risk) of bacteremias and IFD in children receiving allogeneic HSCT, according to the type of donor (matched related [MRD] or alternative [AD]) and presence and grade of aGVHD. From 2000 to 2009, 198 children receiving 217 allogeneic HSCT developed 134 severe infectious episodes (103 bacteremias and 31 IFD). The type of donor (AD versus MRD) was the most important risk factor for the severe infections (P = .0052). In separate multivariable analysis for bacteremia and IFD, children receiving an AD HSCT had increased HR and rate of bacteremia compared with those receiving a MRD transplantation (P = .0171 and P = .0001, respectively), whereas the HR and the rate of IFD were significantly influenced by the grade of aGVHD (P = .0002 and P design management strategies of infections in pediatric allogeneic HSCT.

  16. Panton-Valentine leukocidin does play a role in the early stage of Staphylococcus aureus skin infections: a rabbit model.

    Directory of Open Access Journals (Sweden)

    Urszula Lipinska

    Full Text Available Despite epidemiological data linking necrotizing skin infections with the production of Panton-Valentine leukocidin (PVL, the contribution of this toxin to the virulence of S. aureus has been highly discussed as a result of inconclusive results of in vivo studies. However, the majority of these results originate from experiments using mice, an animal species which neutrophils--the major target cells for PVL--are highly insensitive to the action of this leukocidin. In contrast, the rabbit neutrophils have been shown to be as sensitive to PVL action as human cells, making the rabbit a better experimental animal to explore the PVL role. In this study we examined whether PVL contributes to S. aureus pathogenicity by means of a rabbit skin infection model. The rabbits were injected intradermally with 10(8 cfu of either a PVL positive community-associated methicillin-resistant S. aureus isolate, its isogenic PVL knockout or a PVL complemented knockout strain, and the development of skin lesions was observed. While all strains induced skin infection, the wild type strain produced larger lesions and a higher degree of skin necrosis compared to the PVL knockout strain in the first week after the infection. The PVL expression in the rabbits was indirectly confirmed by a raise in the serum titer of anti-LukS-PV antibodies observed only in the rabbits infected with PVL positive strains. These results indicate that the rabbit model is more suitable for studying the role of PVL in staphylococcal diseases than other animal models. Further, they support the epidemiological link between PVL producing S. aureus strains and necrotizing skin infections.

  17. Actinomyces turicensis Bacteremia Secondary to Pyometra.

    Science.gov (United States)

    Hagiya, Hideharu; Ogawa, Hiroko; Takahashi, Yusuke; Kimura, Kosuke; Hasegawa, Kan; Otsuka, Fumio

    2015-01-01

    We herein present a rare case of Actinomyces turicensis bacteremia that was caused by pyometra. The patient was successfully treated with transvaginal drainage and antibiotic therapy. A literature review in MEDLINE showed that there have been only 8 previously reported cases of A. turicensis bacteremia. This infection frequently occurs in patients with visceral abscesses, and blood culture examinations usually reveal a polymicrobial pattern. However, the prognosis of such patients has been reported to generally be benign. Due to difficulties in performing bacterial identification and the wide-spectrum clinical pictures associated with this bacteremia, no comprehensive understanding of the clinical features of each Actinomyces species has yet been established. PMID:26521910

  18. Role of biofilm-associated protein bap in the pathogenesis of bovine Staphylococcus aureus.

    Science.gov (United States)

    Cucarella, Carme; Tormo, M Angeles; Ubeda, Carles; Trotonda, M Pilar; Monzón, Marta; Peris, Critòfol; Amorena, Beatriz; Lasa, Iñigo; Penadés, José R

    2004-04-01

    Staphylococcus aureus is a common cause of intramammary infections, which frequently become chronic, associated with the ability of the bacteria to produce biofilm. Here, we report a relationship between the ability to produce chronic bovine mastitis and biofilm formation. We have classified bovine mastitis S. aureus isolates into three groups based on the presence of particular genetic elements required for biofilm formation: group 1 (ica(+) bap(+)), group 2 (ica(+), bap negative), and group 3 (ica negative, bap negative). Overall, animals naturally infected with group 1 and 2 isolates had a lower milk somatic cell count than those infected with isolates of group 3. In addition, Bap-positive isolates were significantly more able to colonize and persist in the bovine mammary gland in vivo and were less susceptible to antibiotic treatments when forming biofilms in vitro. Analysis of the structural bap gene revealed the existence of alternate forms of expression of the Bap protein in S. aureus isolates obtained under field conditions throughout the animal's life. The presence of anti-Bap antibodies in serum samples taken from animals with confirmed S. aureus infections indicated the production of Bap during infection. Furthermore, disruption of the ica operon in a bap-positive strain had no effect on in vitro biofilm formation, a finding which strongly suggested that Bap could compensate for the deficiency of the PIA/PNAG product (a biofilm matrix polysaccharide). Altogether, these results demonstrate that, in the bovine intramammary gland, the presence of Bap may facilitate a biofilm formation connected with the persistence of S. aureus.

  19. Analysis of Comorbidity of the Patients Affected by Staphylococcal Bacteremia/Sepsis in the Last Ten Years

    Science.gov (United States)

    Lukovac, Enra; Koluder-Cimic, Nada; Hadzovic-Cengic, Meliha; Baljic, Rusmir; Hadzic, Amir; Gojak, Refet

    2012-01-01

    SUMMARY CONFLICT OF INTEREST: none declared. Introduction Staphylococcal bacteremia/sepsis is one of the most serious bacterial infections around the world. In individuals with pre-existing diseases, there is always an increased risk of infections occurring due to impaired immune system, a variety of drug therapy, exposure to a diagnostic and therapeutic procedure and frequent hospitalizations. Objectives To analyze the prevalence of comorbidity in a patient with the staphylococcal bacteremia/sepsis according to the diagnosis, the site of infection and according to the isolated agent. Patients and methods We analyzed the patients affected by the staphylococcal bacteremia/sepsis and treated in the Clinic for Infectious Diseases during a ten-year period. Results 87 patients were included, out of whom 20 (23%) with clinical signs of the bacteremia and 67 (77%) of sepsis. In the analyzed sample, in 36 (41.4%) were not registered comorbidity. Hospital infections are represented by the previous antibiotic, corticosteroid and chemo therapy, pressure ulcers, and different implants. In all comorbidity, the most common isolated bacteria was S. aureus primarily strain MSSA followed by MRSA strain which is more frequent in patients who were surgically treated (comorbidity–various implants). Conclusion The results suggest the importance of being mindful of the staphylococcal etiology of the bacteremia/sepsis in patients with comorbidities due to the selection of an adequate initial empirical therapy and reducing the risks of the septic shock. PMID:24493989

  20. Comparative Study of Plasma Endotoxin with Procalcitonin Levels in Diagnosis of Bacteremia in Intensive Care Unit Patients

    Institute of Scientific and Technical Information of China (English)

    Tao Wang; Yun-Liang Cui; Zhao-Fen Lin; De-Chang Chen

    2016-01-01

    Background: Both procalcitonin (PCT) and plasma endotoxin levels cannot be solely used for a definite diagnosis ofbacteremia or sepsis, and there has been few study comparing the values of the two biomarkers for the diagnosis of bacteremia.The aim of this study was to identify bacteria causing bacteremia and evaluate the role of the two biomarkers in the diagnosis ofbacteremia in Intensive Care Unit (ICU).Methods: The medical records of 420 patients in ICU were retrospectively reviewed.Patients (n =241) who met the inclusion criteria were subjected to blood culture (BC) for the analysis of the endotoxin or PCT levels.The exclusion criteria included the presence of infection with human immunodeficiency virus and/or AIDS, neutropenia without sepsis, pregnancy, treatment with immunosuppressive therapies, or blood diseases such as hematological tumors.Patients' BC episodes were divided into BC negative, Gram-negative (GN) bacteria, Gram-positive bacteria, and fungi groups.The PCT and plasma endotoxin levels were compared in the different groups.Results: A total of 241 patients with 505 episodes of BC were analyzed.The GN bacteria group showed higher levels of PCT and endotoxin than the BC negative, Gram-positive bacteria, and fungi groups.GN bacteremia was more prevalent than Gram-positive bacteremia.The GN bacteremia caused by non-Enterobacteriaceae infection presented higher endotoxin level than that by Enterobacteriaceae, but no significant difference in PCT levels was observed between the two groups.The plasma endotoxin significantly differed among different groups and was bacterial species dependent.Conclusions: Plasma endotoxin was more related to GN than to Gram-positive bacteremia, and that endotoxin level was species dependent, but PCT level remained relatively more stable within the GN bacteria caused bacteremia.Both GN and positive bacteria caused bacteremia in the ICU patients in different regions of China.And PCT is a more valuable biomarker than endotoxin

  1. Role of golden jackals (Canis aureus) as natural reservoirs of Dirofilaria spp. in Romania

    OpenAIRE

    Ionică, Angela Monica; Matei, Ioana Adriana; D’Amico, Gianluca; Daskalaki, Aikaterini Alexandra; Juránková, Jana; Ionescu, Dan Traian; Mihalca, Andrei Daniel; Modrý, David; Gherman, Călin Mircea

    2016-01-01

    Background Dirofilaria immitis and Dirofilaria repens are mosquito-transmitted zoonotic nematodes, causing heartworm disease and skin lesions, respectively, in carnivores. In Europe, the domestic dog is apparently the main definitive host, but patent infections occur also in other species of carnivores. The rapid spread of the golden jackals (Canis aureus) throughout Europe opens a question of involvement of this species in the sylvatic cycle of pathogens in the colonised territories, includi...

  2. Role of Berberine in the Treatment of Methicillin-Resistant Staphylococcus aureus Infections

    OpenAIRE

    Ming Chu; Ming-bo Zhang; Yan-chen Liu; Jia-rui Kang; Zheng-yun Chu; Kai-lin Yin; Ling-yu Ding; Ran Ding; Rong-xin Xiao; Yi-nan Yin; Xiao-yan Liu; Yue-dan Wang

    2016-01-01

    Berberine is an isoquinoline alkaloid widely used in the treatment of microbial infections. Recent studies have shown that berberine can enhance the inhibitory efficacy of antibiotics against clinical multi-drug resistant isolates of methicillin-resistant Staphylococcus aureus (MRSA). However, the underlying mechanisms are poorly understood. Here, we demonstrated that sub-minimum inhibitory concentrations (MICs) of berberine exhibited no bactericidal activity against MRSA, but affected MRSA b...

  3. Coagulase-negative staphylococcus and enterococcus as predominant pathogens in liver transplant recipients with Gram-positive coccal bacteremia

    Institute of Scientific and Technical Information of China (English)

    SHI Shao-hua; KONG Hai-shen; JIA Chang-ku; XU Jian; ZHANG Wen-jin; WANG Wei-lin; SHEN Yan; ZHANG Min; ZHENG Shu-sen

    2010-01-01

    Background Gram-positive bacteria such as Staphylococcus aureus have been a common cause of infection among liver transplant (LT) recipients in recent decades. The understanding of local epidemiology and its evolving trends with regard to pathogenic spectra and antibiotic susceptibility is beneficial to prophylactic and empiric treatment for LT recipients. This study aimed to investigate etiology, timing, antibiotic susceptibility and risk factors for multidrug resistant (MDR) Gram-positive coccal bacteremia after LT.Methods A cohort analysis of prospectively recorded data was performed to investigate etiologies, timing, antibiotic susceptibility and risk factors for MDR Gram-positive coccal bacteremia in 475 LT recipients.Results In 475 LT recipients in the first six months after LT, there were a total of 98 episodes of bacteremia caused by Gram-positive cocci in 82 (17%) patients. Seventy-five (77%) bacteremic episodes occurred in the first post-LT month.The most frequent Gram-positive cocci were methicillin-resistant coagulase-negative staphylococcus (CoNS, 46 isolates),methicillin-resistant Staphylococcus aureus (MRSA, 13) and enterococcus (34, E. faecium 30, E. faecalis 4). In all Gram-positive bacteremic isolates, 59 of 98 (60%) were MDR. Gram-positive coccal bacteremia and MDR Gram-positive coccal bacteremia predominantly occurred in patients with acute severe exacerbation of chronic hepatitis B and with fulminant/subfulminant hepatitis. Four independent risk factors for development of bacteremia caused by MDR Gram-positive coccus were: LT candidates with encephalopathy grades Ⅱ-Ⅳ (P=0.013, OR: 16.253, 95% CI:1.822-144.995), pre-LT use of empirical antibiotics (P=0.018, OR: 1.029, 95% CI: 1.002-1.057), post-LT urinary tract infections (P <0.001, OR: 20.340, 95% CI: 4.135-100.048) and abdominal infection (P=0.004, OR: 2.820, 95% CI:1.122-10.114). The main infectious manifestations were coinfections due to gram-positive cocci and gram-negative bacilli

  4. Comparative antimicrobial susceptibility of aerobic and facultative bacteria from community-acquired bacteremia to ertapenem in Taiwan

    Directory of Open Access Journals (Sweden)

    Fung Chang-Phone

    2007-07-01

    Full Text Available Abstract Background Ertapenem is a once-a-day carbapenem and has excellent activity against many gram-positive and gram-negative aerobic, facultative, and anaerobic bacteria. The susceptibility of isolates of community-acquired bacteremia to ertapenem has not been reported yet. The present study assesses the in vitro activity of ertapenem against aerobic and facultative bacterial pathogens isolated from patients with community-acquired bacteremia by determining and comparing the MICs of cefepime, cefoxitin, ceftazidime, ceftriaxone, ertapenem, piperacillin, piperacillin-tazobactam, ciprofloxacin, amikacin and gentamicin. The prevalence of extended broad spectrum β-lactamases (ESBL producing strains of community-acquired bacteremia and their susceptibility to these antibiotics are investigated. Methods Aerobic and facultative bacteria isolated from blood obtained from hospitalized patients with community-acquired bacteremia within 48 hours of admission between August 1, 2004 and September 30, 2004 in Chang Gung Memorial Hospital at Keelung, Taiwan, were identified using standard procedures. Antimicrobial susceptibility was evaluated by Etest according to the standard guidelines provided by the manufacturer and document M100-S16 Performance Standards of the Clinical Laboratory of Standard Institute. Antimicrobial agents including cefepime, cefoxitin, ceftazidime, ceftriaxone, ertapenem, piperacillin, piperacillin-tazobactam, ciprofloxacin, amikacin and gentamicin were used against the bacterial isolates to test their MICs as determined by Etest. For Staphylococcus aureus isolates, MICs of oxacillin were also tested by Etest to differentiate oxacillin-sensitive and oxacillin-resistant S. aureus. Results Ertapenem was highly active in vitro against many aerobic and facultative bacterial pathogens commonly recovered from patients with community-acquired bacteremia (128/159, 80.5 %. Ertapenem had more potent activity than ceftriaxone, piperacillin

  5. Bacteremia among Jordanian children at Princess Rahmah Hospital: Pathogens and antimicrobial susceptibility patterns

    Directory of Open Access Journals (Sweden)

    A Mohammad

    2010-06-01

    Full Text Available Objective: To investigate microorganisms causing bacteremia in Jordanian children and to assess their sensitivity to various groups of antimicrobials."nMethods: A retrospective study was conducted on positive blood cultures taken from 378 children aged below 15 year, who sought medical attention at Princess Rahmah Hospital between January and December/2008."nResults: Out of 4475 tested blood samples, 378 isolates were recovered from blood cultures. The male to female isolate ratio was (1.26:1.0. The most frequent pathogen found was Staphylococcus aureus (86.2%, followed by Klebsiella spp. (9%, Escherichia coli (1.9%, Streptococcus spp. (1.9%, Pseudomonas spp. (0.8%, and Acinetobacter sp. was found in only one culture (0.3%. The susceptibility rate of S. aureus was recorded the highest (99.6% for vancomycin, and the lowest susceptibility rate (3.2% was recorded for aztreonam."nConclusions: Staphylococcus aureus was the main isolate in bacteremic children, with all isolates demonstrating susceptibility to vancomycin. Overall, aztreonam resistance was near 97%, and this rate was not affected by sex and blood isolate type. This information should be considered when empirical therapy is recommended or prescribed for children with bacteremia.

  6. Two cases of Ruminococcus gnavus bacteremia associated with diverticulitis

    DEFF Research Database (Denmark)

    Hansen, Sanne Grønvall Kjær; Skov, Marianne N; Justesen, Ulrik S

    2013-01-01

    We report two cases of bacteremia with the anaerobic bacterium Ruminococcus gnavus. In both cases, the bacteremia was associated with diverticular disease. Preliminary conventional identification suggested peptostreptococci, and matrix-assisted laser desorption ionization-time of flight mass...

  7. Immune response and functional role of antibodies raised in heifers against a Staphylococcus aureus CP5 lysate and recombinant antigens vaccine formulated with Iscom Matrix adjuvant.

    Science.gov (United States)

    Camussone, C M; Pujato, N; Renna, M S; Veaute, C M; Morein, B; Marcipar, I S; Calvinho, L F

    2014-12-15

    Staphylococcus aureus is the most frequently isolated pathogen from bovine intramammary infections worldwide. Commercially available vaccines for mastitis control are composed either of S. aureus lysates or inactivated whole-cells formulated with traditional adjuvants. We recently showed the ability of a S. aureus CP5 lysate vaccine adjuvanted with Iscom Matrix to generate a longer lasting specific antibody response in blood and milk, with improved opsonic capacity, compared with a S. aureus CP5 whole-cell formulation. The aim of the present study was to obtain an experimental immunogen composed of lysed cells of a CP5 S. aureus strain supplemented with recombinant clumping factor A, fibronectin binding protein A and β-toxin formulated with Iscom Matrix, characterize the immune response generated when immunizing pregnant heifers and assess the functional role of antibodies raised against this immunogen in experimental models. Both a lysate vaccine and a lysate+recombinant antigens vaccine elicited antibodies that promoted neutrophil phagocytosis and inhibited internalization into mammary epithelial cells, in vitro. Incorporation of defined antigenic molecules to the lysate formulation elicited a strong specific humoral immune response against both lysate and recombinant antigens and was associated with higher expression of regulatory and pro-inflammatory cytokines. In addition, antibodies were efficient for blocking S. aureus binding to bovine fibrinogen and fibronectin, and neutralizing β-toxin effect in vitro, placing these antigens as candidates to be included in a formulation directed to prevent staphylococcal bovine mastitis. PMID:25454469

  8. The Role of Mcl-1 in S. aureus-Induced Cytoprotection of Infected Macrophages

    Directory of Open Access Journals (Sweden)

    Joanna Koziel

    2013-01-01

    cytoprotection of infected cells leading to apoptosis. Increased MCL1 expression in infected cells was associated with enhanced NFκB activation and subsequent IL-6 secretion, since the inhibition of both NFκB and IL-6 signalling pathways abrogated Mcl-1 induction and cytoprotection. Finally, we confirmed our observation in vivo in murine model of septic arthritis showing the association between the severity of arthritis and Mcl-1 expression. Therefore, we propose that S. aureus is hijacking the Mcl-1-dependent inhibition of apoptosis to prevent the elimination of infected host cells, thus allowing the intracellular persistence of the pathogen, its dissemination by infected macrophages, and the progression of staphylococci diseases.

  9. Comparison of the regulation, metabolic functions, and roles in virulence of the glyceraldehyde-3-phosphate dehydrogenase homologues gapA and gapB in Staphylococcus aureus.

    Science.gov (United States)

    Purves, Joanne; Cockayne, Alan; Moody, Peter C E; Morrissey, Julie A

    2010-12-01

    The Gram-positive bacterium Staphylococcus aureus contains two glyceraldehyde-3-phosphate dehydrogenase (GAPDH) homologues known as GapA and GapB. GapA has been characterized as a functional GAPDH protein, but currently there is no biological evidence for the role of GapB in metabolism in S. aureus. In this study we show through a number of complementary methods that S. aureus GapA is essential for glycolysis while GapB is essential in gluconeogenesis. These proteins are reciprocally regulated in response to glucose concentrations, and both are influenced by the glycolysis regulator protein GapR, which is the first demonstration of the role of this regulator in S. aureus and the first indication that GapR homologues control genes other than those within the glycolytic operon. Furthermore, we show that both GapA and GapB are important in the pathogenesis of S. aureus in a Galleria mellonella model of infection, showing for the first time in any bacteria that both glycolysis and gluconeogenesis have important roles in virulence.

  10. The role of innate immunity in promoting SaeR/S-mediated virulence in Staphylococcus aureus.

    Science.gov (United States)

    Zurek, Oliwia W; Nygaard, Tyler K; Watkins, Robert L; Pallister, Kyler B; Torres, Victor J; Horswill, Alexander R; Voyich, Jovanka M

    2014-01-01

    The ability of Staphylococcus aureus to infect tissues is dependent on precise control of virulence through gene-regulatory systems. While the SaeR/S two-component system has been shown to be a major regulator of S. aureus virulence, the influence of the host environment on SaeR/S-regulated genes (saeR/S targets) remains incompletely defined. Using QuantiGene 2.0 transcriptional assays, we examined expression of genes with the SaeR binding site in USA300 exposed to human and mouse neutrophils and host-derived peptides and during subcutaneous skin infection. We found that only some of the saeR/S targets, as opposed to the entire SaeR/S virulon, were activated within 5 and 10 min of interacting with human neutrophils as well as α-defensin. Furthermore, mouse neutrophils promoted transcription of saeR/S targets despite lacking α-defensin, and the murine skin environment elicited a distinctive expression profile of saeR/S targets. These findings indicate that saeR/S-mediated transcription is unique to and dependent on specific host stimuli. By using isogenic USA300ΔsaeR/S and USA300Δagr knockout strains, we also determined that SaeR/S is the major regulator of virulence factors, while Agr, a quorum-sensing two-component system, has moderate influence on transcription of the saeR/S targets under the tested physiological conditions.

  11. Population Genomics of Reduced Vancomycin Susceptibility in Staphylococcus aureus.

    Science.gov (United States)

    Rishishwar, Lavanya; Kraft, Colleen S; Jordan, I King

    2016-01-01

    The increased prevalence of vancomycin-intermediate Staphylococcus aureus (VISA) is an emerging health care threat. Genome-based comparative methods hold great promise to uncover the genetic basis of the VISA phenotype, which remains obscure. S. aureus isolates were collected from a single individual that presented with recurrent staphylococcal bacteremia at three time points, and the isolates showed successively reduced levels of vancomycin susceptibility. A population genomic approach was taken to compare patient S. aureus isolates with decreasing vancomycin susceptibility across the three time points. To do this, patient isolates were sequenced to high coverage (~500×), and sequence reads were used to model site-specific allelic variation within and between isolate populations. Population genetic methods were then applied to evaluate the overall levels of variation across the three time points and to identify individual variants that show anomalous levels of allelic change between populations. A successive reduction in the overall levels of population genomic variation was observed across the three time points, consistent with a population bottleneck resulting from antibiotic treatment. Despite this overall reduction in variation, a number of individual mutations were swept to high frequency in the VISA population. These mutations were implicated as potentially involved in the VISA phenotype and interrogated with respect to their functional roles. This approach allowed us to identify a number of mutations previously implicated in VISA along with allelic changes within a novel class of genes, encoding LPXTG motif-containing cell-wall-anchoring proteins, which shed light on a novel mechanistic aspect of vancomycin resistance. IMPORTANCE The emergence and spread of antibiotic resistance among bacterial pathogens are two of the gravest threats to public health facing the world today. We report the development and application of a novel population genomic

  12. Fatal case of Listeria innocua bacteremia.

    Science.gov (United States)

    Perrin, Monique; Bemer, Michel; Delamare, Catherine

    2003-11-01

    Listeria innocua is widespread in the environment and in food. This species has to date never been described in association with human disease. We report a case of fatal bacteremia caused by L. innocua in a 62-year-old patient.

  13. Vibrio cholerae bacteremia associated with gastrectomy.

    OpenAIRE

    Toeg, A; Berger, S A; Battat, A; Hoffman, M.; Yust, I

    1990-01-01

    Bacteremia due to Vibrio cholerae is rare. Each of 15 cases previously reported in the English language literature occurred in the setting of immune deficiency. We describe an instance of non-serogroup O1 V. cholerae septicemia in an otherwise healthy patient. Susceptibility to such infection may have been enhanced by a prior gastrectomy for duodenal ulcer.

  14. Myroides odoratimimus bacteremia in a diabetic patient.

    Science.gov (United States)

    Endicott-Yazdani, Tiana R; Dhiman, Neelam; Benavides, Raul; Spak, Cedric W

    2015-07-01

    Myroides species are a rare source of human infection. Though not part of the human microbiota, Myroides species are commonly found in the environment. Myroides infections are typically attributed to contact with contaminated water; the most common presentation is in immunocompromised patients. We present a patient with a diabetic foot ulcer who subsequently developed Myroides odoratimimus bacteremia and bone abscess. PMID:26130883

  15. Myroides odoratimimus bacteremia in a diabetic patient

    OpenAIRE

    Endicott-Yazdani, Tiana R.; Dhiman, Neelam; Benavides, Raul; Spak, Cedric W.

    2015-01-01

    Myroides species are a rare source of human infection. Though not part of the human microbiota, Myroides species are commonly found in the environment. Myroides infections are typically attributed to contact with contaminated water; the most common presentation is in immunocompromised patients. We present a patient with a diabetic foot ulcer who subsequently developed Myroides odoratimimus bacteremia and bone abscess.

  16. Role of the LytSR two-component regulatory system in adaptation to cationic antimicrobial peptides in Staphylococcus aureus.

    Science.gov (United States)

    Yang, Soo-Jin; Xiong, Yan Q; Yeaman, Michael R; Bayles, Kenneth W; Abdelhady, Wessam; Bayer, Arnold S

    2013-08-01

    Many host defense cationic antimicrobial peptides (HDPs) perturb the staphylococcal cell membrane (CM) and alter transmembrane potential (ΔΨ) as key parts of their lethal mechanism. Thus, a sense-response system for detecting and mediating adaptive responses to such stresses could impact organism survival; the Staphylococcus aureus LytSR two-component regulatory system (TCRS) may serve as such a ΔΨ sensor. One well-known target of this system is the lrgAB operon, which, along with the related cidABC operon, has been shown to be a regulator in the control of programmed cell death and lysis. We used an isogenic set of S. aureus strains: (i) UAMS-1, (ii) its isogenic ΔlytS and ΔlrgAB mutants, and (iii) plasmid-complemented ΔlytSR and ΔlrgAB mutants. The ΔlytS strain displayed significantly increased in vitro susceptibilities to all HDPs tested (neutrophil-derived human neutrophil peptide 1 [hNP-1], platelet-derived thrombin-induced platelet microbicidal proteins [tPMPs], and the tPMP-mimetic peptide RP-1), as well as to calcium-daptomycin (DAP), a cationic antimicrobial peptide (CAP). In contrast, the ΔlrgAB strain exhibited no significant changes in susceptibilities to these cationic peptides, indicating that although lytSR positively regulates transcription of lrgAB, increased HDP/CAP susceptibilities in the ΔlytS mutant were lrgAB independent. Further, parental UAMS-1 (but not the ΔlytS mutant) became more resistant to hNP-1 and DAP following pretreatment with carbonyl cyanide m-chlorophenylhydrazone (CCCP) (a CM-depolarizing agent). Of note, lytSR-dependent survival against CAP/HDP killing was not associated with changes in either surface positive charge, expression of mprF and dlt, or CM fluidity. The ΔlytS strain (but not the ΔlrgAB mutant) displayed a significant reduction in target tissue survival in an endocarditis model during DAP treatment. Collectively, these results suggest that the lytSR TCRS plays an important role in adaptive responses of

  17. Role of Berberine in the Treatment of Methicillin-Resistant Staphylococcus aureus Infections

    Science.gov (United States)

    Chu, Ming; Zhang, Ming-Bo; Liu, Yan-Chen; Kang, Jia-Rui; Chu, Zheng-Yun; Yin, Kai-Lin; Ding, Ling-Yu; Ding, Ran; Xiao, Rong-Xin; Yin, Yi-Nan; Liu, Xiao-Yan; Wang, Yue-Dan

    2016-04-01

    Berberine is an isoquinoline alkaloid widely used in the treatment of microbial infections. Recent studies have shown that berberine can enhance the inhibitory efficacy of antibiotics against clinical multi-drug resistant isolates of methicillin-resistant Staphylococcus aureus (MRSA). However, the underlying mechanisms are poorly understood. Here, we demonstrated that sub-minimum inhibitory concentrations (MICs) of berberine exhibited no bactericidal activity against MRSA, but affected MRSA biofilm development in a dose dependent manner within the concentration ranging from 1 to 64 μg/mL. Further study indicated that berberine inhibited MRSA amyloid fibrils formation, which consist of phenol-soluble modulins (PSMs). Molecular dynamics simulation revealed that berberine could bind with the phenyl ring of Phe19 in PSMα2 through hydrophobic interaction. Collectively, berberine can inhibit MRSA biofilm formation via affecting PSMs’ aggregation into amyloid fibrils, and thereby enhance bactericidal activity of antibiotics. These findings will provide new insights into the multiple pharmacological properties of berberine in the treatment of microbial-generated amyloid involved diseases.

  18. Different roles for non-receptor tyrosine kinases in arachidonate release induced by zymosan and Staphylococcus aureus in macrophages

    Directory of Open Access Journals (Sweden)

    Sundler Roger

    2006-05-01

    Full Text Available Abstract Background Yeast and bacteria elicit arachidonate release in macrophages, leading to the formation of leukotrienes and prostaglandins, important mediators of inflammation. Receptors recognising various microbes have been identified, but the signalling pathways are not entirely understood. Cytosolic phospholipase A2 is a major down-stream target and this enzyme is regulated by both phosphorylation and an increase in intracellular Ca2+. Potential signal components are MAP kinases, phosphatidylinositol 3-kinase and phospholipase Cγ2. The latter can undergo tyrosine phosphorylation, and Src family kinases might carry out this phosphorylation. Btk, a Tec family kinase, could also be important. Our aim was to further elucidate the role of Src family kinases and Btk. Methods Arachidonate release from murine peritoneal macrophages was measured by prior radiolabeling. Furthermore, immunoprecipitation and Western blotting were used to monitor changes in activity/phosphorylation of intermediate signal components. To determine the role of Src family kinases two different inhibitors with broad specificity (PP2 and the Src kinase inhibitor 1, SKI-1 were used as well as the Btk inhibitor LFM-A13. Results Arachidonate release initiated by either Staphylococcus aureus or yeast-derived zymosan beads was shown to depend on members of the Src kinase family as well as Btk. Src kinases were found to act upstream of Btk, phosphatidylinositol 3-kinase, phospholipase Cγ2 and the MAP kinases ERK and p38, thereby affecting all branches of the signalling investigated. In contrast, Btk was not involved in the activation of the MAP-kinases. Since the cytosolic phospholipase A2 in macrophages is regulated by both phosphorylation (via ERK and p38 and an increase in intracellular Ca2+, we propose that members of the Src kinase family are involved in both types of regulation, while the role of Btk may be restricted to the latter type. Conclusion Arachidonate release

  19. Polymorphism in a lincRNA Associates with a Doubled Risk of Pneumococcal Bacteremia in Kenyan Children.

    Science.gov (United States)

    Rautanen, Anna; Pirinen, Matti; Mills, Tara C; Rockett, Kirk A; Strange, Amy; Ndungu, Anne W; Naranbhai, Vivek; Gilchrist, James J; Bellenguez, Céline; Freeman, Colin; Band, Gavin; Bumpstead, Suzannah J; Edkins, Sarah; Giannoulatou, Eleni; Gray, Emma; Dronov, Serge; Hunt, Sarah E; Langford, Cordelia; Pearson, Richard D; Su, Zhan; Vukcevic, Damjan; Macharia, Alex W; Uyoga, Sophie; Ndila, Carolyne; Mturi, Neema; Njuguna, Patricia; Mohammed, Shebe; Berkley, James A; Mwangi, Isaiah; Mwarumba, Salim; Kitsao, Barnes S; Lowe, Brett S; Morpeth, Susan C; Khandwalla, Iqbal; Blackwell, Jenefer M; Bramon, Elvira; Brown, Matthew A; Casas, Juan P; Corvin, Aiden; Duncanson, Audrey; Jankowski, Janusz; Markus, Hugh S; Mathew, Christopher G; Palmer, Colin N A; Plomin, Robert; Sawcer, Stephen J; Trembath, Richard C; Viswanathan, Ananth C; Wood, Nicholas W; Deloukas, Panos; Peltonen, Leena; Williams, Thomas N; Scott, J Anthony G; Chapman, Stephen J; Donnelly, Peter; Hill, Adrian V S; Spencer, Chris C A

    2016-06-01

    Bacteremia (bacterial bloodstream infection) is a major cause of illness and death in sub-Saharan Africa but little is known about the role of human genetics in susceptibility. We conducted a genome-wide association study of bacteremia susceptibility in more than 5,000 Kenyan children as part of the Wellcome Trust Case Control Consortium 2 (WTCCC2). Both the blood-culture-proven bacteremia case subjects and healthy infants as controls were recruited from Kilifi, on the east coast of Kenya. Streptococcus pneumoniae is the most common cause of bacteremia in Kilifi and was thus the focus of this study. We identified an association between polymorphisms in a long intergenic non-coding RNA (lincRNA) gene (AC011288.2) and pneumococcal bacteremia and replicated the results in the same population (p combined = 1.69 × 10(-9); OR = 2.47, 95% CI = 1.84-3.31). The susceptibility allele is African specific, derived rather than ancestral, and occurs at low frequency (2.7% in control subjects and 6.4% in case subjects). Our further studies showed AC011288.2 expression only in neutrophils, a cell type that is known to play a major role in pneumococcal clearance. Identification of this novel association will further focus research on the role of lincRNAs in human infectious disease. PMID:27236921

  20. Staphylococcus aureus aortitis and retroperitoneal fibrosis: A case report and literature review

    Directory of Open Access Journals (Sweden)

    Marta Yague

    2016-01-01

    Full Text Available An infected aortic aneurysm is a process with high mortality rate. Survival is dependent on an early diagnosis and surgical management. This case report details a rare presentation of aortitis with persistent methicillin-sensitive Staphylococcus aureus (MSSA bacteremia, which initially presented as retroperitoneal fibrosis and was ultimately fatal.

  1. Staphylococcus aureus aortitis and retroperitoneal fibrosis: A case report and literature review.

    Science.gov (United States)

    Yague, Marta; Temprano, Ignacio; Losa, Juan; De Benito, Luis; De La Cruz, Raul; Cheyne, Natalie; Henriquez, Cesar

    2016-01-01

    An infected aortic aneurysm is a process with high mortality rate. Survival is dependent on an early diagnosis and surgical management. This case report details a rare presentation of aortitis with persistent methicillin-sensitive Staphylococcus aureus (MSSA) bacteremia, which initially presented as retroperitoneal fibrosis and was ultimately fatal. PMID:27516965

  2. Risk Factors for Nosocomial Bacterremia Due to Methicillin-Resistant Staphylococcus Aureus

    NARCIS (Netherlands)

    M. Pujol (Miquel); C. Pena; R. Pallares (Roman); J. Ayats (Josefina); J. Ariza (Javier); F. Gudiol (Francesc)

    1994-01-01

    textabstractIn a prospective surveillance study (February 1990–December 1991) performed at a 1000-bed teaching hospital to identify risk factors for nosocomial methicillin-resistantStaphylococcus aureus (MRSA) bacteremia, 309 patients were found to be colonized (n=103; 33 %) or infected (n=206; 67 %

  3. Fatal outcome in bacteremia is characterized by high plasma cell free DNA concentration and apoptotic DNA fragmentation: a prospective cohort study.

    Directory of Open Access Journals (Sweden)

    Reetta Huttunen

    Full Text Available INTRODUCTION: Recent studies have shown that apoptosis plays a critical role in the pathogenesis of sepsis. High plasma cell free DNA (cf-DNA concentrations have been shown to be associated with sepsis outcome. The origin of cf-DNA is unclear. METHODS: Total plasma cf-DNA was quantified directly in plasma and the amplifiable cf-DNA assessed using quantitative PCR in 132 patients with bacteremia caused by Staphylococcus aureus, Streptococcus pneumoniae, ß-hemolytic streptococcae or Escherichia coli. The quality of cf-DNA was analyzed with a DNA Chip assay performed on 8 survivors and 8 nonsurvivors. Values were measured on days 1-4 after positive blood culture, on day 5-17 and on recovery. RESULTS: The maximum cf-DNA values on days 1-4 (n = 132 were markedly higher in nonsurvivors compared to survivors (2.03 vs 1.26 ug/ml, p1.52 ug/ml remained an independent risk factor for case fatality in a logistic regression model. Qualitative analysis of cf-DNA showed that cf-DNA displayed a predominating low-molecular-weight cf-DNA band (150-200 bp in nonsurvivors, corresponding to the size of the apoptotic nucleosomal DNA. cf-DNA concentration showed a significant positive correlation with visually graded apoptotic band intensity (R = 0.822, p<0.001. CONCLUSIONS: Plasma cf-DNA concentration proved to be a specific independent prognostic biomarker in bacteremia. cf-DNA displayed a predominating low-molecular-weight cf-DNA band in nonsurvivors corresponding to the size of apoptotic nucleosomal DNA.

  4. Update on the emerging role of telavancin in hospital-acquired infections

    Directory of Open Access Journals (Sweden)

    Nnedu ON

    2015-04-01

    Full Text Available Obinna N Nnedu,1 George A Pankey2 1Infectious Disease Department, Ochsner Clinic Foundation, New Orleans, LA, USA; 2Infectious Disease Research, Ochsner Clinic Foundation, New Orleans, LA, USA Abstract: Telavancin is a lipoglycopeptide that has activity against gram-positive aerobic and anaerobic bacteria. It has activity against methicillin-resistant Staphylococcus aureus, vancomycin-intermediate S. aureus and non-Van-A strains of vancomycin-resistant enterococci. It has been approved by the US Food and Drug Administration (FDA for complicated skin and skin structure infections and hospital-acquired pneumonia. There is a need for more clinical studies to determine the role of telavancin in treating bacteremia and prosthetic device infections. In this review, we discuss the published data on the use of telavancin in treating hospital-acquired infections and provide an update on new research. Keywords: telavancin, vancomycin, linezolid, Staphylococcus aureus

  5. Bacteremia is associated with excess long-term mortality

    DEFF Research Database (Denmark)

    Nielsen, Stig Lønberg; Lassen, Annmarie Touborg; Gradel, Kim Oren;

    2015-01-01

    OBJECTIVES: Little is known about long-term outcomes following bacteremia. We investigated long-term mortality and causes of death among bacteremia patients compared with population controls. METHODS: Population-based cohort study of bacteremia patients and population controls matched on sex, year...... of birth, residency and calendar time, in Denmark during 2000-2008. We calculated absolute mortality and adjusted mortality rate ratios (MRRs) in predefined follow-up periods. RESULTS: The absolute mortality for bacteremia patients (n = 7783) and population controls (n = 38,906) was 22.0% vs. 0.2% (30 days......-term mortality compared with the general population. The most common causes of death after bacteremia are cancer and cardiovascular diseases. SUMMARY: This population-based cohort study reports an excess long-term mortality among 7783 bacteremia patients compared with matched population controls during 12 years...

  6. Staphylococcus aureus sternal osteomyelitis: a rare cause of chest pain

    Directory of Open Access Journals (Sweden)

    Kaur M

    2015-10-01

    Full Text Available Chest pain is a common presenting symptom with a broad differential. Life-threatening cardiac and pulmonary etiologies of chest pain should be evaluated first. However, it is critical to perform a thorough assessment for other sources of chest pain in order to limit morbidity and mortality from less common causes. We present a rare case of a previously healthy 45 year old man who presented with focal, substernal, reproducible chest pain and Staphylococcus aureus bacteremia who was later found to have primary Staphylococcus aureus sternal osteomyelitis.

  7. Bacteremia with the bovis group streptococci

    DEFF Research Database (Denmark)

    Marmolin, Ea S; Hartmeyer, Gitte N; Christensen, Jens J;

    2016-01-01

    . gallolyticus subsp. gallolyticus with colorectal neoplasia and with infective endocarditis and the association between S. gallolyticus subsp. pasteurianus and pancreatic cancer were found to be clinically important. Also, a very high 1-year mortality rate with S. lutetiensis (66.7%) and S. gallolyticus subsp....... pasteurianus (58.7%) bacteremia calls for intensive investigation for underlying disease focusing on the pancreas and the hepatobiliary system....

  8. Factors Associated with Non-typhoidal Salmonella Bacteremia versus Typhoidal Salmonella Bacteremia in Patients Presenting for Care in an Urban Diarrheal Disease Hospital in Bangladesh

    OpenAIRE

    K M Shahunja; Leung, Daniel T.; Ahmed, Tahmeed; Bardhan, Pradip Kumar; Ahmed, Dilruba; Qadri, Firdausi; Ryan, Edward T.; Chisti, Mohammod Jobayer

    2015-01-01

    Background: Non-typhoidal Salmonella (NTS) and Salmonella enterica serovar Typhi bacteremia are the causes of significant morbidity and mortality worldwide. There is a paucity of data regarding NTS bacteremia in South Asia, a region with a high incidence of typhoidal bacteremia. We sought to determine clinical predictors and outcomes associated with NTS bacteremia compared with typhoidal bacteremia. Methodology We performed a retrospective age-matched case-control study of patients admitted t...

  9. Elucidating the crucial role of poly N-acetylglucosamine from Staphylococcus aureus in cellular adhesion and pathogenesis.

    Directory of Open Access Journals (Sweden)

    Mei Hui Lin

    Full Text Available Staphylococcus aureus is an important pathogen that forms biofilms on the surfaces of medical implants. Biofilm formation by S. aureus is associated with the production of poly N-acetylglucosamine (PNAG, also referred to as polysaccharide intercellular adhesin (PIA, which mediates bacterial adhesion, leading to the accumulation of bacteria on solid surfaces. This study shows that the ability of S. aureus SA113 to adhere to nasal epithelial cells is reduced after the deletion of the ica operon, which contains genes encoding PIA/PNAG synthesis. However, this ability is restored after a plasmid carrying the entire ica operon is transformed into the mutant strain, S. aureus SA113Δica, showing that the synthesis of PIA/PNAG is important for adhesion to epithelial cells. Additionally, S. carnosus TM300, which does not produce PIA/PNAG, forms a biofilm and adheres to epithelial cells after the bacteria are transformed with a PIA/PNAG-expressing plasmid, pTXicaADBC. The adhesion of S. carnosus TM300 to epithelial cells is also demonstrated by adding purified exopolysaccharide (EPS, which contains PIA/PNAG, to the bacteria. In addition, using a mouse model, we find that the abscess lesions and bacterial burden in lung tissues is higher in mice infected with S. aureus SA113 than in those infected with the mutant strain, S. aureus SA113Δica. The results indicate that PIA/PNAG promotes the adhesion of S. aureus to human nasal epithelial cells and lung infections in a mouse model. This study elucidates a mechanism that is important to the pathogenesis of S. aureus infections.

  10. Differential Roles of Poly-N-Acetylglucosamine Surface Polysaccharide and Extracellular DNA in Staphylococcus aureus and Staphylococcus epidermidis Biofilms▿

    OpenAIRE

    Era A Izano; Amarante, Matthew A.; Kher, William B.; Kaplan, Jeffrey B.

    2007-01-01

    Staphylococcus aureus and Staphylococcus epidermidis are major human pathogens of increasing importance due to the dissemination of antibiotic-resistant strains. Evidence suggests that the ability to form matrix-encased biofilms contributes to the pathogenesis of S. aureus and S. epidermidis. In this study, we investigated the functions of two staphylococcal biofilm matrix polymers: poly-N-acetylglucosamine surface polysaccharide (PNAG) and extracellular DNA (ecDNA). We measured the ability o...

  11. Clinical implications of species identification in monomicrobial Aeromonas bacteremia.

    Directory of Open Access Journals (Sweden)

    Chi-Jung Wu

    Full Text Available Advances in Aeromonas taxonomy have led to the reclassification of aeromonads. Hereon, we aimed to re-evaluate the characteristics of Aeromonas bacteremia, including those of a novel species, Aeromonas dhakensis.A retrospective study of monomicrobial Aeromonas bacteremia at a medical center in southern Taiwan from 2004-2011 was conducted. Species identification was based on rpoB sequencing. Of bacteremia of 153 eligible patients, A. veronii (50 isolates, 32.7%, A. dhakensis (48, 31.4%, A. caviae (43, 28.1%, and A. hydrophila (10, 6.5% were the principal causative species. A. dhakensis and A. veronii bacteremia were mainly community-acquired and presented as primary bacteremia, spontaneous bacterial peritonitis, or skin and soft-tissue infection, whereas A. caviae was associated with hospital-onset bacteremia. The distribution of the AmpC β-lactamase and metallo-β-lactamase genes was species-specific: bla(AQU-1, bla(MOX, or bla(CepH was present in A. dhakensis, A. caviae, or A. hydrophila, respectively, and bla(CphA was present in A. veronii, A. dhakensis, and A. hydrophila. The cefotaxime resistance rates of the A. caviae, A. dhakensis, and A. hydrophila isolates were higher than that of A. veronii (39.5%%, 25.0%, and 30% vs. 2%, respectively. A. dhakensis bacteremia was linked to the highest 14-day sepsis-related mortality rate, followed by A. hydrophila, A. veronii, and A. caviae bacteremia (25.5%, 22.2%, 14.0%, and 4.7%, respectively; P = 0.048. Multivariate analysis revealed that A. dhakensis bacteremia, active malignancies, and a Pitt bacteremia score ≥ 4 was an independent mortality risk factor.Characteristics of Aeromonas bacteremia vary between species. A. dhakensis prevalence and its associated poor outcomes suggest it an important human pathogen.

  12. Bacteremia Caused by Raoultella ornithinolytica in Two Children.

    Science.gov (United States)

    Yamakawa, Kiyoshi; Yamagishi, Yuka; Miyata, Kenji; Shimomura, Yasuto; Iwata, Atsuko; Hori, Toshinori; Mikamo, Hiroshige; Okumura, Akihisa

    2016-04-01

    We encountered 2 immunocompromised children complicated by Raoultella ornithinolytica bacteremia. One had received methylprednisolone pulse therapy for IgA nephropathy, and the other had leukopenia because of chemotherapy for leukemia. Both children had no specific symptoms, and R. ornithinolytica bacteremia was identified by routine blood culture. Both patients were successfully treated with antibiotic treatment.

  13. Non-spa-typeable clinical Staphylococcus aureus strains are naturally occurring protein A mutants

    DEFF Research Database (Denmark)

    Baum, Cathrin; Haslinger-Löffler, Bettina; Westh, Henrik;

    2009-01-01

    Staphylococcus aureus is a major human pathogen responsible for increasing the prevalence of community- and hospital-acquired infections. Protein A (SpA) is a key virulence factor of S. aureus and is highly conserved. Sequencing of the variable-number tandem-repeat region of SpA (spa typing......) provides a rapid and reliable method for epidemiological studies. Rarely, non-spa-typeable S. aureus strains are encountered. The reason for this is not known. In this study, we characterized eight non-spa-typeable bacteremia isolates. Sequencing of the entire spa locus was successful for five strains...

  14. Association between Accessory Gene Regulator Polymorphism and Mortality among Critically Ill Patients Receiving Vancomycin for Nosocomial MRSA Bacteremia: A Cohort Study

    Science.gov (United States)

    Cechinel, Angélica; Machado, Denise P.; Turra, Eduardo; Pereira, Dariane; dos Santos, Rodrigo P.; Rosa, Regis G.; Goldani, Luciano Z.

    2016-01-01

    Background. Polymorphism of the accessory gene regulator group II (agr) in methicillin-resistant Staphylococcus aureus (MRSA) is predictive of vancomycin failure therapy. Nevertheless, the impact of group II agr expression on mortality of patients with severe MRSA infections is not well established. Objective. The goal of our study was to evaluate the association between agr polymorphism and all-cause in-hospital mortality among critically ill patients receiving vancomycin for nosocomial MRSA bacteremia. Methods. All patients with documented bacteremia by MRSA requiring treatment in the ICU between May 2009 and November 2011 were included in the study. Cox proportional hazards regression was performed to evaluate whether agr polymorphism was associated with all-cause in-hospital mortality. Covariates included age, APACHE II score, initial C-reactive protein plasma levels, initial serum creatinine levels, vancomycin minimum inhibitory concentration, vancomycin serum levels, and time to effective antibiotic administration. Results. The prevalence of group I and group II agr expression was 52.4% and 47.6%, respectively. Bacteremia by MRSA group III or group IV agr was not documented in our patients. The mean APACHE II of the study population was 24.3 (standard deviation 8.5). The overall cohort mortality was 66.6% (14 patients). After multivariate analysis, initial plasma C-reactive protein levels (P = 0.01), initial serum creatinine levels (P = 0.008), and expression of group II agr (P = 0.006) were positively associated with all-cause in-hospital mortality. Patients with bacteremia by MRSA with group II agr expression had their risk of death increased by 12.6 times when compared with those with bacteremia by MRSA with group I agr expression. Conclusion. Group II agr polymorphism is associated with an increase in mortality in critically ill patients with bacteremia by MRSA treated with vancomycin. PMID:27366180

  15. Association between Accessory Gene Regulator Polymorphism and Mortality among Critically Ill Patients Receiving Vancomycin for Nosocomial MRSA Bacteremia: A Cohort Study

    Directory of Open Access Journals (Sweden)

    Angélica Cechinel

    2016-01-01

    Full Text Available Background. Polymorphism of the accessory gene regulator group II (agr in methicillin-resistant Staphylococcus aureus (MRSA is predictive of vancomycin failure therapy. Nevertheless, the impact of group II agr expression on mortality of patients with severe MRSA infections is not well established. Objective. The goal of our study was to evaluate the association between agr polymorphism and all-cause in-hospital mortality among critically ill patients receiving vancomycin for nosocomial MRSA bacteremia. Methods. All patients with documented bacteremia by MRSA requiring treatment in the ICU between May 2009 and November 2011 were included in the study. Cox proportional hazards regression was performed to evaluate whether agr polymorphism was associated with all-cause in-hospital mortality. Covariates included age, APACHE II score, initial C-reactive protein plasma levels, initial serum creatinine levels, vancomycin minimum inhibitory concentration, vancomycin serum levels, and time to effective antibiotic administration. Results. The prevalence of group I and group II agr expression was 52.4% and 47.6%, respectively. Bacteremia by MRSA group III or group IV agr was not documented in our patients. The mean APACHE II of the study population was 24.3 (standard deviation 8.5. The overall cohort mortality was 66.6% (14 patients. After multivariate analysis, initial plasma C-reactive protein levels (P=0.01, initial serum creatinine levels (P=0.008, and expression of group II agr (P=0.006 were positively associated with all-cause in-hospital mortality. Patients with bacteremia by MRSA with group II agr expression had their risk of death increased by 12.6 times when compared with those with bacteremia by MRSA with group I agr expression. Conclusion. Group II agr polymorphism is associated with an increase in mortality in critically ill patients with bacteremia by MRSA treated with vancomycin.

  16. Phenotypes and Virulence among Staphylococcus aureus USA100, USA200, USA300, USA400, and USA600 Clonal Lineages

    OpenAIRE

    King, Jessica M.; Kulhankova, Katarina; Stach, Christopher S.; Vu, Bao G.; Salgado-Pabón, Wilmara

    2016-01-01

    ABSTRACT Staphylococcus aureus diseases affect ~500,000 individuals per year in the United States. Worldwide, the USA100, USA200, USA400, and USA600 lineages cause many of the life-threatening S. aureus infections, such as bacteremia, infective endocarditis, pneumonia, toxic shock syndrome, and surgical site infections. However, the virulence mechanisms associated with these clonal lineages, in particular the USA100 and USA600 isolates, have been severely understudied. We investigated the vir...

  17. Predominant association of Raoultella bacteremia with diseases of the biliary tract.

    Science.gov (United States)

    de Jong, Eefje; Erkens-Hulshof, Sandra; van der Velden, Lieven B J; Voss, Andreas; Bosboom, Ron; Hodiamont, Caspar J; Wever, Peter C; Rentenaar, Rob J; Sturm, Patrick D

    2014-02-01

    A case series of 14 patients with Raoultella bacteremia was compared with 28 Klebsiella oxytoca and 28 Klebsiella pneumoniae bacteremia cases. Forty-three percent of Raoultella bacteremia cases were associated with biliary tract disease, compared to 32% and 22% of patients with K. oxytoca and K. pneumoniae bacteremia, respectively.

  18. Clinical characteristics and significance of Streptococcus salivarius bacteremia and Streptococcus bovis bacteremia: a prospective 16-year study.

    Science.gov (United States)

    Corredoira, J C; Alonso, M P; García, J F; Casariego, E; Coira, A; Rodriguez, A; Pita, J; Louzao, C; Pombo, B; López, M J; Varela, J

    2005-04-01

    The aim of this study was to determine the clinical significance of Streptococcus salivarius isolates recovered from blood cultures and compare them with isolates of Streptococcus bovis biotypes I and II. Seventeen of the 52 (32%) S. salivarius isolates recovered were considered clinically significant, compared with 62 of the 64 (97%) S. bovis isolates (p<0.0001). Bacteremia caused by S. salivarius occurred mostly in patients who showed relevant disruption of the mucous membranes and/or serious underlying diseases. Patients with S. salivarius bacteremia were younger than those with S. bovis bacteremia (57 vs. 67 years; p<0.01). Patients with S. salivarius bacteremia and patients with S. bovis II bacteremia had similar rates of endocarditis, colon tumors, and non-colon cancer. On the other hand, when compared with S. bovis I bacteremia, S. salivarius bacteremia was associated with lower rates of endocarditis (18% vs. 74%, respectively) (p<0.01) and colon tumors (0% vs. 57%, respectively) (p<0.005) and higher rates of non-colon cancer (53% vs. 9.5%, respectively) (p<0.01). Bacteremia caused by S. bovis II had a hepatobiliary origin in 50% of the patients, while, in contrast, that due to S. salivarius or S. bovis I was less frequently associated with a hepatobiliary origin (12% and 5%, respectively) (p<0.00001). The rate of penicillin resistance was 31% among S. salivarius isolates and 0% among S. bovis isolates (p<0.0001). In conclusion, the clinical characteristics of S. salivarius bacteremia and S. bovis II bacteremia are similar, and the isolation of S. salivarius in blood should not be systematically regarded as contamination. PMID:15902530

  19. Staphylococcus aureus vaccines: Deviating from the carol.

    Science.gov (United States)

    Missiakas, Dominique; Schneewind, Olaf

    2016-08-22

    Staphylococcus aureus, a commensal of the human nasopharynx and skin, also causes invasive disease, most frequently skin and soft tissue infections. Invasive disease caused by drug-resistant strains, designated MRSA (methicillin-resistant S. aureus), is associated with failure of antibiotic therapy and elevated mortality. Here we review polysaccharide-conjugate and subunit vaccines that were designed to prevent S. aureus infection in patients at risk of bacteremia or surgical wound infection but failed to reach their clinical endpoints. We also discuss vaccines with ongoing trials for combinations of polysaccharide-conjugates and subunits. S. aureus colonization and invasive disease are not associated with the development of protective immune responses, which is attributable to a large spectrum of immune evasion factors. Two evasive strategies, assembly of protective fibrin shields via coagulases and protein A-mediated B cell superantigen activity, are discussed as possible vaccine targets. Although correlates for protective immunity are not yet known, opsonophagocytic killing of staphylococci by phagocytic cells offers opportunities to establish such criteria. PMID:27526714

  20. Role of Staphylococcus aureus Virulence Factors in Inducing Inflammation and Vascular Permeability in a Mouse Model of Bacterial Endophthalmitis.

    Directory of Open Access Journals (Sweden)

    Ajay Kumar

    Full Text Available Staphylococcus (S. aureus is a common causative agent of bacterial endophthalmitis, a vision threatening complication of eye surgeries. The relative contribution of S. aureus virulence factors in the pathogenesis of endophthalmitis remains unclear. Here, we comprehensively analyzed the development of intraocular inflammation, vascular permeability, and the loss of retinal function in C57BL/6 mouse eyes, challenged with live S. aureus, heat-killed S. aureus (HKSA, peptidoglycan (PGN, lipoteichoic acid (LTA, staphylococcal protein A (SPA, α-toxin, and Toxic-shock syndrome toxin 1 (TSST1. Our data showed a dose-dependent (range 0.01 μg/eye to 1.0 μg/eye increase in the levels of inflammatory mediators by all virulence factors. The cell wall components, particularly PGN and LTA, seem to induce higher levels of TNF-α, IL-6, KC, and MIP2, whereas the toxins induced IL-1β. Similarly, among the virulence factors, PGN induced higher PMN infiltration. The vascular permeability assay revealed significant leakage in eyes challenged with live SA (12-fold and HKSA (7.3-fold, in comparison to other virulence factors (~2-fold and controls. These changes coincided with retinal tissue damage, as evidenced by histological analysis. The electroretinogram (ERG analysis revealed a significant decline in retinal function in eyes inoculated with live SA, followed by HKSA, SPA, and α-toxin. Together, these findings demonstrate the differential innate responses of the retina to S. aureus virulence factors, which contribute to intraocular inflammation and retinal function loss in endophthalmitis.

  1. Selenium Plays a Protective Role in Staphylococcus aureus-Induced Endometritis in the Uterine Tissue of Rats.

    Science.gov (United States)

    Liu, Yuzhu; Qiu, Changwei; Li, Wenyu; Mu, Weiwei; Li, Chengye; Guo, Mengyao

    2016-10-01

    The essential trace element selenium (Se) modulates the functions of many regulatory proteins in signal transduction, conferring benefits in inflammatory diseases. Endometritis is a reproductive obstacle disease both in humans and animals. Staphylococcus aureus is the major pathogen that causes endometritis. The present study analyzes the protection and mechanism of Se-methylselenocysteine (MSC) and methylseleninic acid (MSA) on S. aureus-induced endometritis. An atomic fluorescence spectrophotometry study showed that the uterine Se content increased with the addition of MSC and MSA. Histopathology observation and TUNEL detection showed that Se supplementation displayed a greater defense against uterine inflammatory damage. The quantitative PCR (qPCR) and ELISA analyses showed that the expressions of tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) increased with S. aureus infection and decreased with the addition of MSC and MSA. The Toll-like receptor 2 (TLR2) expression showed the same status as the inflammatory cytokines. The Western blot results showed that the increased phosphorylation of IκBα and NF-κB p65 was also reduced by the addition of MSC and MSA. The qPCR and Western blot results also showed that the transcription expressions and the protein dissociation of caspase-9, caspase-3, caspase-7, caspase-6, and poly(ADP-ribose) polymerase (PARP), which were increased by S. aureus infection, were inhibited by Se supplementation. All of the results displayed that the protection conferred by MSC was stronger than MSA. The present study indicated the Se supplementation might be a potential prevention and control measure for S. aureus-induced endometritis. PMID:26920733

  2. Contribution of coagulases towards Staphylococcus aureus disease and protective immunity.

    Directory of Open Access Journals (Sweden)

    Alice G Cheng

    Full Text Available The bacterial pathogen Staphylococcus aureus seeds abscesses in host tissues to replicate at the center of these lesions, protected from host immune cells via a pseudocapsule. Using histochemical staining, we identified prothrombin and fibrin within abscesses and pseudocapsules. S. aureus secretes two clotting factors, coagulase (Coa and von Willebrand factor binding protein (vWbp. We report here that Coa and vWbp together are required for the formation of abscesses. Coa and vWbp promote the non-proteolytic activation of prothrombin and cleavage of fibrinogen, reactions that are inhibited with specific antibody against each of these molecules. Coa and vWbp specific antibodies confer protection against abscess formation and S. aureus lethal bacteremia, suggesting that coagulases function as protective antigens for a staphylococcal vaccine.

  3. Increasing incidence of hospital-acquired and healthcare-associated bacteremia in northeast Thailand: a multicenter surveillance study.

    Directory of Open Access Journals (Sweden)

    Maliwan Hongsuwan

    Full Text Available BACKGROUND: Little is known about the epidemiology of nosocomial bloodstream infections in public hospitals in developing countries. We evaluated trends in incidence of hospital-acquired bacteremia (HAB and healthcare-associated bacteremia (HCAB and associated mortality in a developing country using routinely available databases. METHODS: Information from the microbiology and hospital databases of 10 provincial hospitals in northeast Thailand was linked with the national death registry for 2004-2010. Bacteremia was considered hospital-acquired if detected after the first two days of hospital admission, and healthcare-associated if detected within two days of hospital admission with a prior inpatient episode in the preceding 30 days. RESULTS: A total of 3,424 patients out of 1,069,443 at risk developed HAB and 2,184 out of 119,286 at risk had HCAB. Of these 1,559 (45.5% and 913 (41.8% died within 30 days, respectively. Between 2004 and 2010, the incidence rate of HAB increased from 0.6 to 0.8 per 1,000 patient-days at risk (p<0.001, and the cumulative incidence of HCAB increased from 1.2 to 2.0 per 100 readmissions (p<0.001. The most common causes of HAB were Acinetobacter spp. (16.2%, Klebsiella pneumoniae (13.9%, and Staphylococcus aureus (13.9%, while those of HCAB were Escherichia coli (26.3%, S. aureus (14.0%, and K. pneumoniae (9.7%. There was an overall increase over time in the proportions of ESBL-producing E. coli causing HAB and HCAB. CONCLUSIONS: This study demonstrates a high and increasing incidence of HAB and HCAB in provincial hospitals in northeast Thailand, increasing proportions of ESBL-producing isolates, and very high associated mortality.

  4. Staphylococcus aureus and hand eczema severity

    DEFF Research Database (Denmark)

    Haslund, P; Bangsgaard, N; Jarløv, J O;

    2009-01-01

    BACKGROUND: The role of bacterial infections in hand eczema (HE) remains to be assessed. OBJECTIVES: To determine the prevalence of Staphylococcus aureus in patients with HE compared with controls, and to relate presence of S. aureus, subtypes and toxin production to severity of HE. METHODS......: Bacterial swabs were taken at three different visits from the hand and nose in 50 patients with HE and 50 controls. Staphylococcus aureus was subtyped by spa typing and assigned to clonal complexes (CCs), and isolates were tested for exotoxin-producing S. aureus strains. The Hand Eczema Severity Index...... was used for severity assessment. RESULTS: Staphylococcus aureus was found on the hands in 24 patients with HE and four controls (P aureus was found to be related to increased severity of the eczema (P aureus types on the hands...

  5. Raoultella Planticola Bacteremia Following Consumption of Seafood

    Directory of Open Access Journals (Sweden)

    Philip W Lam

    2014-01-01

    Full Text Available Raoultella planticola is a Gram-negative bacillus commonly found in water, soil and aquatic environments. There have only been 16 cases of R planticola infection documented in the literature to date. R planticola possesses the ability to convert histidine to histamine and can produce symptoms of scombroid poisoning when poorly prepared seafood is consumed in large amounts. The present report describes a case involving a 56-year-old woman who presented with R planticola bacteremia and symptoms consistent with cholangitis four days after consuming a seafood salad containing squid and octopus. She was successfully treated with intravenous ceftriaxone followed by oral ciprofloxacin. Recent chemotherapy, proton pump inhibitor use and altered biliary flow secondary to hepatic metastases may have been contributing factors to the pathogenesis of disease.

  6. Raoultella planticola bacteremia following consumption of seafood.

    Science.gov (United States)

    Lam, Philip W; Salit, Irving E

    2014-07-01

    Raoultella planticola is a Gram-negative bacillus commonly found in water, soil and aquatic environments. There have only been 16 cases of R planticola infection documented in the literature to date. R planticola possesses the ability to convert histidine to histamine and can produce symptoms of scombroid poisoning when poorly prepared seafood is consumed in large amounts. The present report describes a case involving a 56-year-old woman who presented with R planticola bacteremia and symptoms consistent with cholangitis four days after consuming a seafood salad containing squid and octopus. She was successfully treated with intravenous ceftriaxone followed by oral ciprofloxacin. Recent chemotherapy, proton pump inhibitor use and altered biliary flow secondary to hepatic metastases may have been contributing factors to the pathogenesis of disease.

  7. Campylobacter bacteremia: A rare and under-reported event?

    NARCIS (Netherlands)

    Louwen, R.; Baarlen, van P.; Vliet, van A.H.M.; Belkum, van A.; Hays, J.P.; Endtz, H.P.

    2012-01-01

    Bacteria belonging to the species Campylobacter are the most common cause of bacterial diarrhoea in humans. The clinical phenotype associated with Campylobacter infections ranges from asymptomatic conditions to severe colitis and bacteremia. In susceptible patients, Campylobacter infections are asso

  8. The incidence and prognosis of patients with bacteremia

    DEFF Research Database (Denmark)

    Nielsen, Stig Lønberg

    2015-01-01

    for an overall incidence rate of 215.7 per 100,000 person years including 99.0 for community-acquired, 50.0 for healthcare-associated and 66.7 for nosocomial bacteremia. The overall incidence rate decreased by 23.3% (95% CI, 17.8%-28.4%) from year 2000 to 2008 (3.3% per year, prates...... of community-acquired bacteremia (3.7% per year, p year, pincidence rate of healthcare-associated bacteremia remained more or less stable throughout the study period (p=0.17). The crude incidence rates decreased for Escherichia coli, Staphylococcus......-time bacteremias per admission for an overall incidence of 14.2 per 1000 admissions and 23.6 per 10,000 bed days; highest for males, elderly individuals (> 65 years), and patients initially admitted to the Departments of Hematology, Nephrology, Internal Medicine, Urology or Oncology. The daily incidence...

  9. OXA-48-Producing Enterobacteriaceae Causing Bacteremia, United Arab Emirates

    Directory of Open Access Journals (Sweden)

    Chulsoo Ahn

    2015-01-01

    Full Text Available OXA-48-producing isolates were identified in approximately 4% and less than 1% of ESBL-producing and non-ESBL-producing E. coli and K. pneumoniae causing bacteremia at the largest tertiary hospital in Abu Dhabi.

  10. Staphylococcus saprophyticus bacteremia after ESWL in an immunocompetent woman.

    Science.gov (United States)

    Hofmans, M; Boel, A; Van Vaerenbergh, K; De Beenhouwer, H

    2015-06-01

    Staphylococcus saprophyticus is a well-known cause of uncomplicated urinary tract infections, especially in young and sexually active women. Presence in blood cultures is rare and often attributed to contamination. When bacteremia is significant, it occurs mostly in patients with hematologic malignancies and is predominantly catheter-related. However, we describe a case of significant bacteremia with S. saprophyticus associated with urinary tract infection after extracorporeal shock wave lithotripsy of an ureterolithiasis in an otherwise healthy patient.

  11. Staphylococcus saprophyticus bacteremia after ESWL in an immunocompetent woman.

    Science.gov (United States)

    Hofmans, M; Boel, A; Van Vaerenbergh, K; De Beenhouwer, H

    2015-06-01

    Staphylococcus saprophyticus is a well-known cause of uncomplicated urinary tract infections, especially in young and sexually active women. Presence in blood cultures is rare and often attributed to contamination. When bacteremia is significant, it occurs mostly in patients with hematologic malignancies and is predominantly catheter-related. However, we describe a case of significant bacteremia with S. saprophyticus associated with urinary tract infection after extracorporeal shock wave lithotripsy of an ureterolithiasis in an otherwise healthy patient. PMID:25523318

  12. Bacteremia with Bacteroides pyogenes after a cat bite

    DEFF Research Database (Denmark)

    Madsen, Ida Ringsborg; Justesen, Ulrik Stenz

    2011-01-01

    Animal bite wounds are often infected with bacteria from the animal's oral flora. We report what we believe to be the first case of bacteremia with Bacteroides pyogenes resulting from an infected cat bite.......Animal bite wounds are often infected with bacteria from the animal's oral flora. We report what we believe to be the first case of bacteremia with Bacteroides pyogenes resulting from an infected cat bite....

  13. EDIN-B Promotes the Translocation of Staphylococcus aureus to the Bloodstream in the Course of Pneumonia

    Directory of Open Access Journals (Sweden)

    Johan Courjon

    2015-10-01

    Full Text Available It is crucial to define risk factors that contribute to host invasion by Staphylococcus aureus. Here, we demonstrate that the chromosomally encoded EDIN-B isoform from S. aureus contributes to the onset of bacteremia during the course of pneumonia. Deletion of edinB in a European lineage community-acquired methicillin resistant S. aureus (CA-MRSA strain (ST80-MRSA-IV dramatically decreased the frequency and magnitude of bacteremia in mice suffering from pneumonia. This deletion had no effect on the bacterial burden in both blood circulation and lung tissues. Re-expression of wild-type EDIN-B, unlike the catalytically inactive mutant EDIN-R185E, restored the invasive characteristics of ST80-MRSA-IV.

  14. Staphylococcus hyicus Bacteremia in a Farmer ▿

    OpenAIRE

    Casanova, Carlo; Iselin, Lukas; von Steiger, Niklaus; Droz, Sara; Sendi, Parham

    2011-01-01

    Bacteria known in animal infectious diseases can cause challenges in human diagnostic laboratories. We present pitfalls in the identification and susceptibility testing of Staphylococcus hyicus, a pathogen that typically causes exudative epidermitis in pigs. In this case, the coagulase-positive staphylococcus isolated from a septic patient was misidentified as Staphylococcus aureus.

  15. Increasing Prevalence of Methicillin-Resistant Staphylococcus aureus Causing Nosocomial Infections at a University Hospital in Taiwan from 1986 to 2001

    OpenAIRE

    Hsueh, Po-Ren; Teng, Lee-Jene; Chen, Wen-Hwei; Pan, Huei-Ju; Chen, Mei-Lin; Chang, Shan-Chwen; Luh, Kwen-Tay; Lin, Fang-Yue

    2004-01-01

    A rapid emergence of nosocomial methicillin-resistant Staphylococcus aureus (MRSA) infection (from 26.3% in 1986 to 77% in 2001) was found. The susceptibility of 200 nonduplicate blood isolates of MRSA and 100 MRSA isolates causing refractory bacteremia to 22 antimicrobial agents disclosed that glycopeptides, quinupristin-dalfopristin, and linezolid remained the most active agents.

  16. TNF and CD28 Signaling Play Unique but Complementary Roles in the Systemic Recruitment of Innate Immune Cells after Staphylococcus aureus Enterotoxin A Inhalation.

    Science.gov (United States)

    Svedova, Julia; Tsurutani, Naomi; Liu, Wenhai; Khanna, Kamal M; Vella, Anthony T

    2016-06-01

    Staphylococcus aureus enterotoxins cause debilitating systemic inflammatory responses, but how they spread systemically and trigger inflammatory cascade is unclear. In this study, we showed in mice that after inhalation, Staphylococcus aureus enterotoxin A rapidly entered the bloodstream and induced T cells to orchestrate systemic recruitment of inflammatory monocytes and neutrophils. To study the mechanism used by specific T cells that mediate this process, a systems approach revealed inducible and noninducible pathways as potential targets. It was found that TNF caused neutrophil entry into the peripheral blood, whereas CD28 signaling, but not TNF, was needed for chemotaxis of inflammatory monocytes into blood and lymphoid tissue. However, both pathways triggered local recruitment of neutrophils into lymph nodes. Thus, our findings revealed a dual mechanism of monocyte and neutrophil recruitment by T cells relying on overlapping and nonoverlapping roles for the noninducible costimulatory receptor CD28 and the inflammatory cytokine TNF. During sepsis, there might be clinical value in inhibiting CD28 signaling to decrease T cell-mediated inflammation and recruitment of innate cells while retaining bioactive TNF to foster neutrophil circulation. PMID:27183621

  17. Ceftaroline Fosamil Use in 2 Pediatric Patients With Invasive Methicillin-Resistant Staphylococcus aureus Infections

    OpenAIRE

    Williams, Amanda W.; Newman, Patrick M; Ocheltree, Sara; Beaty, Rachel; Hassoun, Ali

    2015-01-01

    Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is one of the most common pathogens causing pediatric infections including skin and soft tissue infections, pyogenic arthritis, osteomyelitis, and septic shock. For decades, patients were treated with antibiotics such as vancomycin and clindamycin, but there is an increasing incidence of resistance to these traditional therapies. We describe 2 cases of patients with CA-MRSA invasive infections with bacteremia who exper...

  18. Bacteremias por bacilos gram-negativos

    Directory of Open Access Journals (Sweden)

    Adrelírio J. R. Gonçalves

    1969-01-01

    Full Text Available São apresentados 31 casos de bacteremia por gram-negativos, assunto que vem merecendo muita atenção dos pesquisadores nos últimos anos. Os organismos etiológicos mais importantes que apareceram em igualdade de freqüência foram Escherichia coli e Klebsiella-Aerobacter, sendo responsáveis por 58% do total das infecções, seguidos por Pseudomonas. A porta de entrada mais freqüente foi o trato urinário em 61,3% dos casos. A infecção foi mais comum no sexo masculino e a faixa etária de 50 a 60 anos predominou. O uso prévio de antibióticos foi um fator predisponente muito importante, seguido pelo uso de esteróides e citostáticos. As principais doenças predisponentes foram diabetes mellitus e neoplasias malignas. Os principais fatores precipitantes foram a manipulação do aparelho urinário, com infecção prévia ou desencadeada, cirurgia do aparelho digestivo, uronatia obstrutiva e obstrução biliar. As principais manifestações clínicas foram a presença de febre, calafrios e hipotensão arterial. A complicação mais freqüente foi o choque bacteriano que incidiu em 58% dos casos, aproximadamente três vêzes aquela relatada na literatura. As outras foram a insuficiência renal aguda, superinfecção e infecção pulmonar metastática. Considerações terapêuticas gerais e esquemas de antibióticos são propostos para estes casos. A mortalidade da bacteremia simples foi de 30,7% e quando associada ao choque elevou-se para 72,2% . As infecções por Pseudomonas foram 100% fatais.

  19. DEVELOPMENT OF BACTEREMIA IN VENTILATOR ASSOCIATED PNUEMONIA PATIENTS AT A TERTIARY CARE HOSPITAL, GUJARAT- A PROSPECTIVE STUDY

    Directory of Open Access Journals (Sweden)

    Payal Modi

    2011-04-01

    Full Text Available Ventilator Associated Pneumonia (VAP is second most common cause of nosocomial infection. It also increases length of stay in hospital & cost for the patient. The ‘American Thoracic Society’ guidelines for Hospital Acquired Pneumonia recognize that when bronchoscopy is not performed blood cultures may be of value both to isolate an etiologic agent & define severity. Aim: The present study was carried out to measure the prevalence of bacteremia in pt. with VAP. Methodology: In this prospective study 100 patients aged 0-12 years, admitted in ICU & put on ventilator at S.S.G.Hospital, Vadodara from 1st Sep. 2010 to 31st September 2011 were enrolled. The Endotracheal secretion culture & Blood culture were performed after 48hrs of ventilation. The samples were processed as per standard microbiological methods. In case of ET secretion culture, >106 cfu/ml was considered significant for the presence of bacteremia. Result: Of total 100 patients, 85 were Endotracheal secretion culture positive. Blood culture was positive in 38 of these 85 patients. Out of these 38 patients 30 (79% patients showed the same organism as was recovered from the Endotracheal secretion culture. VAP was developed in 85% of patients (85 of 100 & bacteremia was present in 44% of VAP patients but 30 out of 38 (79% cases of bacteremia were of pulmonary origin. Conclusion: The presence of Bacteremia in the patients with Hospital Acquired Pneumonia is considered to have important role for defining the aetiology. [National J of Med Res 2011; 1(2.000: 23-26

  20. Bacteremia during quinsy and elective tonsillectomy

    DEFF Research Database (Denmark)

    Klug, Tejs Ehlers; Henriksen, Jens-Jacob; Rusan, Maria;

    2012-01-01

    . Ninety-three percent of the isolated strains were sensitive to amoxicillin, and all were sensitive to amoxicillin with clavulanic acid. Discussion: Our results challenge the distinction made by the European Society of Cardiology between elective and quinsy tonsillectomy, with regard to antibiotic...... prophylaxis recommendation only to patients undergoing procedures to treat an established infection. To provide full empiric coverage, including coverage for Staphylococcus aureus, we advocate the use of amoxicillin with clavulanic acid in patients at high risk of infective endocarditis....

  1. Klebsiella ESBL bacteremia-mortality and risk factors

    Directory of Open Access Journals (Sweden)

    Felipe Francisco Tuon

    2011-12-01

    Full Text Available Background: Extended spectrum β-lactamase (ESBL-producing bacteria have become recognized as a problem in South America. The aim of this study was to evaluate risk factors and mortality rate in bacteremia caused by ESBL-producing Klebsiella pneumoniae in a Brazilian hospital. Methods: A three-year retrospective cohort study with 104 cases of K. pneumoniae bacteremia (61 ESBL and 43 non-ESBL. Several clinical and laboratory variables were evaluated. The outcome of interest was 30-day mortality. The adequate treatment was evaluated according to antibiotic susceptibility. Results: Multivariable analysis showed that central venous catheter and mechanical ventilation were independent risk factors for ESBL. The duration of hospitalization before the bacteremia was not a risk factor. Mortality was similar in ESBL and non-ESBL and inadequate therapy was not shown to be a risk factor. Conclusion: ESBL-producing Klebsiella bacteremia can occur early, suggesting that a carbapenem should be included in the initial empirical therapy for bacteremia in patients under mechanical ventilation and/or central venous catheter in our institution.

  2. Bacteremia during adenoidectomy: a comparison of suction diathermy adenoid ablation and adenoid curettage.

    LENUS (Irish Health Repository)

    Casserly, Paula

    2010-08-01

    Transient bacteremia is induced by adenoidectomy when the integrity of the nasopharyngeal membrane is broken. The aim of this study was to determine the incidence of bacteremia in patients undergoing adenoidectomy, to identify the causative organisms, and to compare the incidences of bacteremia between the two techniques suction diathermy and curettage.

  3. Predominant association of Raoultella bacteremia with diseases of the biliary tract

    NARCIS (Netherlands)

    Jong, Eefje de; Erkens-Hulshof, S.; Velden, L.B. van der; Voss, A.; Bosboom, R.; Hodiamont, C.J.; Wever, P.C.; Rentenaar, R.J.; Sturm, P.D.J.

    2014-01-01

    A case series of 14 patients with Raoultella bacteremia was compared with 28 Klebsiella oxytoca and 28 Klebsiella pneumoniae bacteremia cases. Forty-three percent of Raoultella bacteremia cases were associated with biliary tract disease, compared to 32% and 22% of patients with K. oxytoca and K. pne

  4. Nosocomial bloodstream infection in patients caused by Staphylococcus aureus: drug susceptibility, outcome, and risk factors for hospital mortality

    Institute of Scientific and Technical Information of China (English)

    CHEN Rong; YAN Zhong-qiang; FENG Dan; LUO Yan-ping; WANG Lei-li; SHEN Ding-xia

    2012-01-01

    Background Previous studies have different viewpoints about the clinical impact of methicillin resistance on mortality of hospital-acquired bloodstream infection (BSI) patients with Staphylococcus aureus (S.aureus).The objective of this study was to investigate the mortality of hospital-acquired BSI with S.aureus in a military hospital and analyze the risk factors for the hospital mortality.Methods A retrospective cohort study was performed in patients admitted to the biggest military tertiary teaching hospital in China between January 2006 and May 2011.All included patients had clinically significant nosocomial BSI with S.aureus.Multivariate Logistic regression analysis was used to identify the risk factors for hospital mortality of patients with S.aureus BSI.Results One hundred and eighteen patients of more than one year old were identified as clinically and microbiologically confirmed nosocomial bacteraemia due to S.aureus,and 75 out of 118 patients were infected with methicillin-resistant S.aureus (MRSA).The overall mortality of nosocomial S.aureus BSI was 28.0%.Methicillin resistance in S.aureus bacteremia was associated with significant increase in the length of hospitalization and high proportion of inappropriate empirical antibiotic treatment.After Logistic regression analysis,the severity of clinical manifestations (APACHE Ⅱ score) (odds ratio (OR) 1.22,95% confidence interval (CI) 1.12-1.34) and inadequacy of empirical antimicrobial therapy (OR 0.25,95% CI 0.09-0.69) remained as risk factors for hospital mortality.Conclusions Nosocomial S.aureus BSI was associated with high in-hospital mortality.Methicillin resistance in S.aureus has no significant impact on the outcome of patients with staphylococcal bacteremia.Proper empirical antimicrobial therapy is very important to the prognosis.

  5. Non-spa-typeable clinical Staphylococcus aureus strains are naturally occurring protein A mutants

    DEFF Research Database (Denmark)

    Baum, Cathrin; Haslinger-Löffler, Bettina; Westh, Henrik;

    2009-01-01

    Staphylococcus aureus is a major human pathogen responsible for increasing the prevalence of community- and hospital-acquired infections. Protein A (SpA) is a key virulence factor of S. aureus and is highly conserved. Sequencing of the variable-number tandem-repeat region of SpA (spa typing......) provides a rapid and reliable method for epidemiological studies. Rarely, non-spa-typeable S. aureus strains are encountered. The reason for this is not known. In this study, we characterized eight non-spa-typeable bacteremia isolates. Sequencing of the entire spa locus was successful for five strains...... and revealed various mutations of spa, all of which included a deletion of immunoglobulin G binding domain C, in which the upper primer for spa typing is located, while two strains were truly spa negative. This is the first report demonstrating that nontypeability of S. aureus by spa sequencing is due either...

  6. A severe Morganella morganii endophthalmitis; followed by bacteremia

    Directory of Open Access Journals (Sweden)

    Tayfur Demiray

    2016-03-01

    Full Text Available Morganella morganii is rarely isolated from nosocomial infections. However, postoperative infections due to Morganella spp. were documented in literature and eye involvements of the infections usually result in severe sequels.  We present a severe case infection, which was caused by M. morganii subsp. morganii, firstly appearing as conjunctivitis and complicated by bacteremia. The infectious agent isolated from both conjunctival and consecutive blood cultures. Identification and anti- microbial susceptibility tests were performed with the Vitek 2® automated system. The isolate was resistant to cephalosporins and carbapenems and it had ability to produce extended spectrum beta-lactamases. Patient was successfully treated with intravenous ciprofloxacin according to susceptibility test results. This is the first report of M. morganii infection detected as a local infection then complicated by bacteremia. Keywords: Morganella morganii, conjunctivitis, bacteremia, ciprofloxacin

  7. Deep venous thrombosis and pulmonary embolism detected by FDG PET/CT in a patient with bacteremia

    DEFF Research Database (Denmark)

    Nielsen, Anne Lerberg; Thomassen, Anders; Hess, Søren;

    2013-01-01

    We report incidental FDG PET/CT findings of deep venous thrombosis and pulmonary embolism in a patient with bacteremia. In this patient, diagnosis of thromboembolism was not considered until FDG PET/CT imaging was performed, and the findings prompted immediate anticoagulant therapy. The role of FDG...... PET/CT in venous thromboembolism is not yet well established, but the potential benefit must be kept in mind when interpreting FDG PET/CT images regardless of the underlying disease....

  8. Comparative Study of Plasma Endotoxin with Procalcitonin Levels in Diagnosis of Bacteremia in Intensive Care Unit Patients

    Directory of Open Access Journals (Sweden)

    Tao Wang

    2016-01-01

    Conclusions: Plasma endotoxin was more related to GN than to Gram-positive bacteremia, and that endotoxin level was species dependent, but PCT level remained relatively more stable within the GN bacteria caused bacteremia. Both GN and positive bacteria caused bacteremia in the ICU patients in different regions of China. And PCT is a more valuable biomarker than endotoxin in the diagnosis of bacteremia.

  9. Shewanella alga bacteremia in two patients with lower leg ulcers

    DEFF Research Database (Denmark)

    Domínguez, H.; Vogel, Birte Fonnesbech; Gram, Lone;

    1996-01-01

    The first Danish cases of Shewanella alga bacteremia in two patients with chronic lower leg ulcers are reported. Both patients were admitted to the hospital during the same month of a very warm summer and had been exposed to the same marine environment, thereby suggesting the same source of infec......The first Danish cases of Shewanella alga bacteremia in two patients with chronic lower leg ulcers are reported. Both patients were admitted to the hospital during the same month of a very warm summer and had been exposed to the same marine environment, thereby suggesting the same source......'Etoile, France), but further genetic and physiological analyses identified them as Shewanella alga....

  10. Piperine Plays an Anti-Inflammatory Role in Staphylococcus aureus Endometritis by Inhibiting Activation of NF-κB and MAPK Pathways in Mice

    Directory of Open Access Journals (Sweden)

    Wen-jun Zhai

    2016-01-01

    Full Text Available Endometritis is commonly caused by pathogenic microorganisms, including Staphylococcus aureus (S. aureus. Piperine, which is a natural medicine, has shown a variety of biological activities. To explore the effect and mechanism of piperine on S. aureus endometritis, a mouse model of S. aureus endometritis was successfully established in the present study. Histopathological changes were observed with H&E staining, cytokines were analyzed by ELISA, mRNA was analyzed by qPCR, and proteins were detected by western blot. The results showed that piperine could significantly alleviate inflammatory injury in S. aureus endometritis. The qPCR and ELISA results showed that piperine effectively reduced the S. aureus-induced overexpression of TNF-α, IL-1β, and IL-6 but increased the expression of IL-10. The S. aureus-induced inflammation was related to TLR-2 and TLR-4 because the results showed that their expression was increased in S. aureus infection but then decreased with piperine treatment. To further confirm that piperine caused an anti-inflammatory response by targeting NF-κB and MAPKs, the expression of I-κB, p65, p38, ERK, and JNK was measured. The phosphorylation of I-κB, p65, p38, ERK, and JNK was inhibited by piperine in a dose-dependent manner. All of the results indicated that piperine may be a potential anti-inflammatory drug both in endometritis and in other S. aureus-induced diseases.

  11. Piperine Plays an Anti-Inflammatory Role in Staphylococcus aureus Endometritis by Inhibiting Activation of NF-κB and MAPK Pathways in Mice.

    Science.gov (United States)

    Zhai, Wen-Jun; Zhang, Zhen-Biao; Xu, Nian-Nian; Guo, Ying-Fang; Qiu, Changwei; Li, Cheng-Ye; Deng, Gan-Zhen; Guo, Meng-Yao

    2016-01-01

    Endometritis is commonly caused by pathogenic microorganisms, including Staphylococcus aureus (S. aureus). Piperine, which is a natural medicine, has shown a variety of biological activities. To explore the effect and mechanism of piperine on S. aureus endometritis, a mouse model of S. aureus endometritis was successfully established in the present study. Histopathological changes were observed with H&E staining, cytokines were analyzed by ELISA, mRNA was analyzed by qPCR, and proteins were detected by western blot. The results showed that piperine could significantly alleviate inflammatory injury in S. aureus endometritis. The qPCR and ELISA results showed that piperine effectively reduced the S. aureus-induced overexpression of TNF-α, IL-1β, and IL-6 but increased the expression of IL-10. The S. aureus-induced inflammation was related to TLR-2 and TLR-4 because the results showed that their expression was increased in S. aureus infection but then decreased with piperine treatment. To further confirm that piperine caused an anti-inflammatory response by targeting NF-κB and MAPKs, the expression of I-κB, p65, p38, ERK, and JNK was measured. The phosphorylation of I-κB, p65, p38, ERK, and JNK was inhibited by piperine in a dose-dependent manner. All of the results indicated that piperine may be a potential anti-inflammatory drug both in endometritis and in other S. aureus-induced diseases. PMID:27293467

  12. Staphylococcus aureus alpha-toxin induces apoptosis in peripheral blood mononuclear cells : role of endogenous tumour necrosis factor-alpha and the mitochondrial death pathway

    NARCIS (Netherlands)

    Haslinger, Bettina; Strangfeld, Katrin; Peters, Georg; Schulze-Osthoff, Klaus; Sinha, Bhanu

    2003-01-01

    Staphylococcus aureus infections can result in septic and toxic shock with depletion of immune cells and massive cytokine production. Recently, we showed that, in S. aureus-infected Jurkat T cells, alpha-toxin is the major mediator of caspase activation and apoptosis. Here, we investigated the mecha

  13. Empirical therapy in Methicillin-resistant Staphylococcus Aureus infections: An Up-To-Date approach.

    Science.gov (United States)

    VanEperen, Alison S; Segreti, John

    2016-06-01

    Methicillin-resistant Staphylococcus aureus (MRSA) continues to be an important pathogen worldwide, with high prevalence of infection in both community and hospital settings. Timely and appropriate choice of empirical therapy in the setting of MRSA infection is imperative due to the high rate of associated morbidity and mortality with MRSA infections. Initial choices should be made based on the site and severity of the infection, most notably moderate skin and soft tissue infections which may be treated with oral antibiotics (trimethoprim-sulfamethoxazole, clindamycin, doxycycline/minocycline, linezolid) in the outpatient setting, versus choice of parenteral therapy in the inpatient setting of more invasive or severe disease. Though the current recommendations continue to strongly rely on vancomycin as a standard empiric choice in the setting of severe/invasive infections, alternative therapies exist with studies supporting their non-inferiority. This includes the use of linezolid in pneumonia and severe skin and skin structure infections (SSSI) and daptomycin for MRSA bacteremia, endocarditis, SSSIs and bone/joint infections. Additionally, concerns continue to arise in regards to vancomycin, such as increasing isolate MICs, and relatively high rates of clinical failures with vancomycin. Thus, the growing interest in vanomycin alternatives, such as ceftaroline, ceftobribole, dalbavancin, oritavancin, and tedizolid, and their potential role in treating MRSA infections.

  14. Empirical therapy in Methicillin-resistant Staphylococcus Aureus infections: An Up-To-Date approach.

    Science.gov (United States)

    VanEperen, Alison S; Segreti, John

    2016-06-01

    Methicillin-resistant Staphylococcus aureus (MRSA) continues to be an important pathogen worldwide, with high prevalence of infection in both community and hospital settings. Timely and appropriate choice of empirical therapy in the setting of MRSA infection is imperative due to the high rate of associated morbidity and mortality with MRSA infections. Initial choices should be made based on the site and severity of the infection, most notably moderate skin and soft tissue infections which may be treated with oral antibiotics (trimethoprim-sulfamethoxazole, clindamycin, doxycycline/minocycline, linezolid) in the outpatient setting, versus choice of parenteral therapy in the inpatient setting of more invasive or severe disease. Though the current recommendations continue to strongly rely on vancomycin as a standard empiric choice in the setting of severe/invasive infections, alternative therapies exist with studies supporting their non-inferiority. This includes the use of linezolid in pneumonia and severe skin and skin structure infections (SSSI) and daptomycin for MRSA bacteremia, endocarditis, SSSIs and bone/joint infections. Additionally, concerns continue to arise in regards to vancomycin, such as increasing isolate MICs, and relatively high rates of clinical failures with vancomycin. Thus, the growing interest in vanomycin alternatives, such as ceftaroline, ceftobribole, dalbavancin, oritavancin, and tedizolid, and their potential role in treating MRSA infections. PMID:27066882

  15. Helicobacter canis bacteremia in a renal transplant patient

    NARCIS (Netherlands)

    van der Vusse, M. L.; van Son, W. J.; Ott, A.; Manson, W.

    2014-01-01

    Here we present a case report of a 41-year-old woman suffering from high fever and bacteremia due to Helicobacter canis, 11months after kidney transplantation. Identification of H.canis was achieved by 16s rDNA sequence analysis of a positive blood culture. The patient was restored fully to health a

  16. Risk factors for mortality in patients with Stenotrophomonas maltophilia bacteremia

    Science.gov (United States)

    Jeon, Yong Duk; Jeong, Woo Yong; Kim, Moo Hyun; Jung, In Young; Ahn, Mi Young; Ann, Hea Won; Ahn, Jin Young; Han, Sang Hoon; Choi, Jun Yong; Song, Young Goo; Kim, June Myung; Ku, Nam Su

    2016-01-01

    Abstract Stenotrophomonas maltophilia is a nosocomial pathogen associated with high morbidity and mortality, particularly in immunocompromised or critically ill patients. In this study, we investigated the risk factors for mortality in patients with S. maltophilia bacteremia. Retrospectively, medical records from all patients with S. maltophilia bacteremia between December 2005 and 2014 at Severance Hospital, a 2000-bed tertiary care hospital in Seoul, Korea, were reviewed. Analysis was performed to identify factors associated with 28-day mortality. In total, 142 bacteremia patients were enrolled in this study. The overall 28-day mortality rate was 36.6%. Based on the univariate analysis, hematologic malignancy (P = 0.015), Sepsis-related Organ Failure Assessment (SOFA) score (P < 0.001) and the removal of a central venous catheter (CVC) (P = 0.040) were significantly related to mortality. In the intensive care unit patients, the Acute Physiology and Chronic Health Evaluation II score (P = 0.001) also had significance. Based on the multivariate analysis, the SOFA score (odds ratio [OR] = 1.323; 95% confidence interval [CI]: 1.159, 1.509; P < 0.001) and removal of the CVC (OR = 0.330; 95% CI: 0.109, 0.996; P = 0.049) were independent factors associated with mortality. Our results suggest that removing a CVC may considerably reduce mortality in patients with S. maltophilia bacteremia. PMID:27495046

  17. Clostridium glycolicum Bacteremia in a Bone Marrow Transplant Patient▿

    OpenAIRE

    Elsayed, Sameer; Zhang, Kunyan

    2007-01-01

    We describe a case of Clostridium glycolicum bacteremia and septic shock in an adult woman with a recent bone marrow transplant for relapsed Hodgkin's disease. The bacterium was identified by 16S rRNA gene sequencing. This is the first published report of the recovery of this organism from human clinical material.

  18. Bacteremia caused by viridans streptococci in 71 children.

    Science.gov (United States)

    Gaudreau, C; Delage, G; Rousseau, D; Cantor, E D

    1981-12-01

    A review of the hospital records of 71 patients from whose blood viridans streptococci were isolated showed that in 13 cases the patient's illness was definitely related to the bacteremia: 4 patients had endocarditis, 3 had pneumonia, 2 had peritonitis and 1 each had meningitis, a scalp wound infection, sinusitis and otitis media. The bacteremia may have contributed to the two deaths among these 13 patients. In 45 cases the viridans streptococci may have contributed to the patient's illness: 15 patients had an infection of the lower respiratory tract and 7 an infection of the upper respiratory tract, 8 were neonates with suspected septicemia, 3 had soft tissue infections, 3 had leukemia and sepsis, and 9 had miscellaneous infections; the bacteremia was unrelated to the two deaths in this group. In another 13 cases the viridans streptococci could not be related to the patient's illness. The species most frequently isolated were Streptococcus mitis, S. sanguis II and S. MG-intermedius. The outcome of the bacteremia was generally good, even among the 11 patients not treated with antibiotics. When viridans streptococci are cultured from a single blood sample, further samples of blood and, if feasible, specimens from the associated focus of infection should be obtained for culture; further blood cultures are especially important in cases of suspected endocarditis.

  19. Risk Factors of Endocarditis in Patients with Enterococcus faecalis Bacteremia

    DEFF Research Database (Denmark)

    Dahl, Anders; Lauridsen, Trine K; Arpi, Magnus;

    2016-01-01

    BACKGROUND:  The NOVA score is a recently developed diagnostic tool to identify patients with increased risk of infective endocarditis (IE) among patients with Enterococcus faecalis (EF) bacteremia. We aim to validate an adapted version of the NOVA score and to identify risk factors for IE...

  20. Raoultella ornithinolytica bacteremia in an infant with visceral heterotaxy.

    Science.gov (United States)

    Mau, Nicole; Ross, Lawrence A

    2010-05-01

    A case of Raoultella ornithinolytica bacteremia in an infant with visceral heterotaxy is reported. Physical examination was remarkable for markedly red skin flushing, not unlike that seen during histamine fish poisoning. R. ornithinolytica is a histamine-producing bacterium recently elucidated as a major cause of histamine fish poisoning. Only 2 other cases of human infection by R. ornithinolytica have been reported.

  1. Raoultella ornithinolytica bacteremia in cancer patients: report of three cases.

    Science.gov (United States)

    Hadano, Yoshiro; Tsukahara, Mika; Ito, Kenta; Suzuki, Jun; Kawamura, Ichiro; Kurai, Hanako

    2012-01-01

    Raoultella ornithinolytica is a Gram-negative aerobic bacillus reclassified in the new genus from the Klebsiella species based on new genetic approaches; however, human infections caused by R. ornithinolytica are rare. We herein report three cases of R. ornithinolytica bacteremia associated with biliary tract infections in cancer patients. R. ornithinolytica can be a causative pathogen of biliary tract infection in cancer patients.

  2. Correlation of tumor necrosis factor-β and interleukin-1 gene cluster polymorphism with susceptibility to bacteremia in patients undergoing kidney transplantation

    Institute of Scientific and Technical Information of China (English)

    WU Xiao-xia; WAN Qi-quan; YE Qi-fa; ZHOU Jian-dang

    2013-01-01

    Background Bacteremia remains a significant cause of morbidity and mortality after kidney transplantation.This study was conducted to investigate whether the polymorphisms of tumor necrosis factor (TNF)-β,interleukin (IL)-1β,and IL-1 receptor antagonist (IL-1ra) gene predicted the susceptibility to bacteremia within the first 6 months after kidney transplantation.Methods Subjects comprised 82 infected kidney transplant recipients and 60 non-infected kidney transplant recipients.Bacteremia was diagnosed in 16 of the 82 infected recipients.Genomic DNA from these 142 kidney transplant recipients was extracted from peripheral blood leukocytes.Regions containing the Ncol polymorphic site at position +252 of TNF-βgene and the Aval polymorphic site at position-511 of IL-1β gene were amplified by polymerase chain reaction (PCR) and subsequently digested with Ncol and Aval restriction enzymes,respectively.The polymorphic regions within intron 2 of IL-1ra gene containing variable numbers of a tandem repeat (VNTR) of 86 base pairs were amplified by PCR.Results Genotypic and allelic frequencies were similar between infected recipients and non-infected ones.Individual locus analysis showed that recipient TNF-β and IL-1ra gene polymorphisms were not associated with the presence of bacteremia (P=0.684 and P=0.567,respectively).However,genotype analysis revealed that recipient IL-1β-511CC genotype was strongly associated with susceptibility to develop bacteremia (P=0.003).Recipient IL-1β-511CC genotype (odds ratio 5.242,95% confidence intervals 1.645-16.706,P=0.005) independently predicted the risk for bacteremia within the first 6 months after kidney transplantation.Conclusions These findings indicate a critical role of IL-1β gene polymorphisms in susceptibility to bacteremia after kidney transplantation,which may be useful to screen for patients at higher risk for post-transplant bacteremias.Thus,the identified individuals can benefit from preventive treatment and a

  3. Prevalence and detection of mixed-population enterococcal bacteremia.

    Science.gov (United States)

    Cárdenas, Ana María; Andreacchio, Kathleen A; Edelstein, Paul H

    2014-07-01

    Mixed-population (heterogeneous) enterococcal bacteremia (MEB) is rarely reported. Based on one occasion in which Vitek2 missed a vancomycin-resistant subpopulation isolated from a patient, we developed a simple method to detect this subpopulation and determined MEB frequency. The four patients presented here had either Enterococcus faecium or Enterococcus faecalis bacteremia caused by both vancomycin-resistant enterococci (VRE) and vancomycin-susceptible enterococci (VSE). No prior common antibiotic therapy was observed, and bacteremia resolved with daptomycin, gentamicin, and/or linezolid treatment. In two cases, VRE presence was missed by Vitek2. To detect the VRE subpopulation, tryptic soy broth was inoculated from positive blood cultures and a saline suspension was inoculated to a vancomycin (6-μg/ml) (V6) plate. Two isolates from each patient were studied further. Relatedness was assessed by multilocus sequence typing, fitness was evaluated by growth curve and competition assays, and vanA presence was determined by PCR. MEB represented ∼5% of all enterococcal bacteremias. All VRE subpopulations grew on V6 plates but were missed in two instances by Vitek2. VRE and VSE isolates from each patient were closely related and did not differ in overall fitness. All four VRE isolates and 2/4 VSE isolates were vanA positive. MEBs occur regardless of prior antimicrobial therapy, are relatively common in our hospital, and are important to detect. As far as we know, this study is the first to report heterogeneous E. faecalis bacteremia. There is a simple method to detect VRE subpopulations that may be missed by Vitek2.

  4. Clinical manifestations and prognostic factors of Morganella morganii bacteremia.

    Science.gov (United States)

    Lin, T-Y; Chan, M-C; Yang, Y-S; Lee, Y; Yeh, K-M; Lin, J-C; Chang, F-Y

    2015-02-01

    Although Morganella morganii causes a variety of clinical infections, there are limited studies on M. morganii bacteremia after the year 2000. A total of 109 patients with M. morganii bacteremia at a medical center in Taiwan from 2003 to 2012 were studied. Among them, 30.3 % had polymicrobial bacteremia and 75.2 % had community-acquired infection. The most common underlying diseases were hypertension (62.4 %) and diabetes mellitus (38.5 %). The urinary tract (41.3 %) was the major portal of entry, followed by the hepatobiliary tract (27.5 %), skin and soft tissue (21.1 %), and primary bacteremia (10.1 %). Susceptibility testing of M. morganii isolates showed ubiquitous resistance to first-generation cephalosporins and ampicillin-clavulanate; resistance rates to gentamicin, piperacillin-tazobactam, and ciprofloxacin were 30.3 %, 1.8 %, and 10.1 %, respectively. Overall, the 14-day mortality was 14.7 %. Univariate analysis revealed that elevated blood urea nitrogen (BUN) values [p = 0.0137, odds ratio (OR) 5.26], intensive care unit (ICU) admission (p = 0.011, OR 4.4), and higher Acute Physiology and Chronic Health Evaluation II (APACHE II) scores (p < 0.001, OR 1.62) were significantly associated with mortality. The APACHE II score remained the only significant risk factor for mortality in multivariate analysis (p = 0.0012, OR 1.55). In conclusion, M. morganii bacteremia patients were mostly elderly, with one or more comorbidities. Most of the patients had community-acquired infection via the urinary and hepatobiliary tracts. Furthermore, prognosis can be predicted according to disease severity measured by the APACHE II score.

  5. Active surveillance to determine the impact of methicillin resistance on mortality in patients with bacteremia and influences of the use of antibiotics on the development of MRSA infection

    Directory of Open Access Journals (Sweden)

    Juliana Pena Porto

    2013-12-01

    Full Text Available Introduction Methicillin-resistant Staphylococcus aureus (MRSA is among the most important pathogens of nosocomial infections, mainly in intensive care units (ICUs, and accounts for 40-60% of all healthcare-associated S. aureus infections. We evaluated the incidence of nosocomial infection by S. aureus, identified the risk factors for MRSA infection, and evaluated the effect of resistance to methicillin on mortality in patients. Methods We conducted MRSA surveillance at a university hospital in Brazil from January 1, 2010, to December 31, 2010, and performed a retrospective case-control matched study to evaluate the frequency of subsequent MRSA bacteremia and death among patients. We evaluated and compared the risk factors between patients with MRSA and methicillin-sensitive Staphylococcus aureus (MSSA infection. Results Sepsis was the most common cause of infection (17.7/1,000 patient-days, followed by surgical site (11.4/1,000 patient-days, pneumonia (4.1/1,000 patient-days, and urinary tract infection (2.4/1,000 patient-days. The significant risk factors were time of hospitalization, use of central vascular catheter (CVC, urinary catheter, nasogastric tube, parenteral nutrition, tracheostomy, mechanical ventilation, and previous antibiotic administration, the latter of which was the only independent risk factor for MRSA infection. Mortality was significantly higher in patients with MRSA. The number of antibiotics tested was not related to increases in the frequency of MRSA/1,000 patient-days. The incidence of mortality attributable to MRSA (bloodstream infection BSI was 50%. Conclusions Surveillance results showed that the use of high levels of antibiotics was directly related to the development of MRSA infection, and the mortality attributable to MRSA in patients with bacteremia was significant.

  6. The role of micro-organisms (Staphylococcus aureus and Candida albicans in the pathogenesis of breast pain and infection in lactating women: study protocol

    Directory of Open Access Journals (Sweden)

    Tabrizi Sepehr N

    2011-07-01

    Full Text Available Abstract Background The CASTLE (Candida and Staphylococcus Transmission: Longitudinal Evaluation study will investigate the micro-organisms involved in the development of mastitis and "breast thrush" among breastfeeding women. To date, the organism(s associated with the development of breast thrush have not been identified. The CASTLE study will also investigate the impact of physical health problems and breastfeeding problems on maternal psychological health in the early postpartum period. Methods/Design The CASTLE study is a longitudinal descriptive study designed to investigate the role of Staphylococcus spp (species and Candida spp in breast pain and infection among lactating women, and to describe the transmission dynamics of S. aureus and Candida spp between mother and infant. The relationship between breastfeeding and postpartum health problems as well as maternal psychological well-being is also being investigated. A prospective cohort of four hundred nulliparous women who are at least thirty six weeks gestation pregnant are being recruited from two hospitals in Melbourne, Australia (November 2009 to June 2011. At recruitment, nasal, nipple (both breasts and vaginal swabs are taken and participants complete a questionnaire asking about previous known staphylococcal and candidal infections. Following the birth, participants are followed-up six times: in hospital and then at home weekly until four weeks postpartum. Participants complete a questionnaire at each time points to collect information about breastfeeding problems and postpartum health problems. Nasal and nipple swabs and breast milk samples are collected from the mother. Oral and nasal swabs are collected from the baby. A telephone interview is conducted at eight weeks postpartum to collect information about postpartum health problems and breastfeeding problems, such as mastitis and nipple and breast pain. Discussion This study is the first longitudinal study of the role of both

  7. Staphylococcus aureus and Pregnancy

    Science.gov (United States)

    Staphylococcus aureus and Pregnancy In every pregnancy, a woman starts out with a 3-5% chance of ... risk. This sheet talks about whether exposure to staphylococcus aureus may increase the risk for birth defects ...

  8. Bacteriemia en pacientes internados con celulitis Bacteremia in patients hospitalized with cellulitis

    Directory of Open Access Journals (Sweden)

    Juan S. Lasa

    2012-08-01

    Full Text Available La celulitis es una inflamación aguda de la dermis y tejido celular subcutáneo de causa bacteriana, que generalmente complica a heridas, úlceras y dermatosis, aunque de manera frecuente no existe sitio de entrada. Se recomienda la realización de cultivo de punción de piel y partes blandas (PPB. Los hemocultivos raramente dan resultados positivos. El objetivo de este trabajo fue determinar la prevalencia de bacteriemia en pacientes internados en nuestra institución con diagnóstico de celulitis. Se analizaron retrospectivamente los registros clínicos de los pacientes con este diagnóstico al ingreso entre junio de 2007 y marzo de 2010. Se evaluaron los datos poblacionales, presencia de comorbilidades, y resultados de los cultivos. En ese período, se internaron 140 pacientes con diagnóstico de celulitis y a todos ellos se les realizó hemocultivo y cultivos de PPB. Setenta y cuatro eran varones (52.8%. La edad promedio: 47.5 ± 19.7 años (rango 16-94. El 40% tuvo cultivos positivos de PPB, en los que el Staphylococcus aureus meticilino resistente (SAMR fue el germen más frecuentemente aislado (35.7%; la prevalencia de bacteriemia fue del 8.6%, en donde el germen más frecuente fue Streptoccocus Beta hemolítico, grupo G (33% del total de hemocultivos positivos. La bacteriemia se asoció significativamente a mayor estadía hospitalaria (10.5 ± 8.9 vs. 4.9 ± 6, p = 0.004. Se asoció con mayor riesgo de hemocultivo positivo a ser diabético, tener cultivo de PPB positivo, consumo de alcohol y/o enfermedad pulmonar obstructiva crónica.Cellulitis is an acute inflammation of dermis and subcutaneous tissue, usually complicating wounds, ulcers, or dermatosis. Even though in these cases it is recommended to perform culture from skin and soft tissue samples, the utility of blood cultures remains controversial due to the low frequency of positive results. Here we report the prevalence of bacteremia in patients with cellulitis admitted in our

  9. The daily risk of bacteremia during hospitalization and associated 30-day mortality evaluated in relation to the traditional classification of bacteremia

    DEFF Research Database (Denmark)

    Nielsen, Stig Lønberg; Lassen, Annmarie Touborg; Kolmos, Hans Jørn;

    2016-01-01

    BACKGROUND: We investigated the overall and daily incidence of bacteremia among hospitalized patients and evaluated the traditional classification of bacteremia (community-onset vs nosocomial based on a 48-hour time window) by means of the daily incidence and associated 30-day mortality. METHODS...

  10. Rhodococcus bacteremia in cancer patients is mostly catheter related and associated with biofilm formation.

    Directory of Open Access Journals (Sweden)

    Fadi Al Akhrass

    Full Text Available Rhodococcus is an emerging cause of opportunistic infection in immunocompromised patients, most commonly causing cavitary pneumonia. It has rarely been reported as a cause of isolated bacteremia. However, the relationship between bacteremia and central venous catheter is unknown. Between 2002 and 2010, the characteristics and outcomes of seventeen cancer patients with Rhodococcus bacteremia and indwelling central venous catheters were evaluated. Rhodococcus bacteremias were for the most part (94% central line-associated bloodstream infection (CLABSI. Most of the bacteremia isolates were Rhodococcus equi (82%. Rhodococcus isolates formed heavy microbial biofilm on the surface of polyurethane catheters, which was reduced completely or partially by antimicrobial lock solution. All CLABSI patients had successful response to catheter removal and antimicrobial therapy. Rhodococcus species should be added to the list of biofilm forming organisms in immunocompromised hosts and most of the Rhodococcus bacteremias in cancer patients are central line associated.

  11. MF59- and Al(OH3-adjuvanted Staphylococcus aureus (4C-Staph vaccines induce sustained protective humoral and cellular immune responses, with a critical role for effector CD4 T cells at low antibody titers.

    Directory of Open Access Journals (Sweden)

    Elisabetta eMonaci

    2015-09-01

    Full Text Available Staphylococcus aureus (S. aureus is an important opportunistic pathogen that may cause invasive life-threatening infections like sepsis and pneumonia. Due to increasing antibiotic-resistance, the development of an effective vaccine against S. aureus is needed. Although a correlate of protection against staphylococcal diseases is not yet established, several findings suggest that both antibodies and CD4 T cells might contribute to optimal immunity. In this study, we show that adjuvanting a multivalent vaccine (4C-Staph with MF59, an oil-in-water emulsion licensed in human vaccines, further potentiated antigen-specific IgG titers and CD4 T cell responses compared to alum and conferred protection in the peritonitis model of S. aureus infection. Moreover, we showed that MF59- and alum-adjuvanted 4C-Staph vaccines induced persistent antigen-specific humoral and T cell responses, and protected mice from infection up to 4 months after immunization. Furthermore, 4C-Staph formulated with MF59 was used to investigate which immune compartment is involved in vaccine-induced protection. Using CD4 T cell-depleted mice or B cell deficient mice, we demonstrated that both T and B cell responses contributed to 4C-Staph vaccine-mediated protective immunity. However, the role of CD4 T cells seemed more evident in the presence of low antibody responses. This study provides preclinical data further supporting the use of the adjuvanted 4C-Staph vaccines against S. aureus diseases, and provides critical insights on the correlates of protective immunity necessary to combat this pathogen.

  12. Elizabethkingia anophelis bacteremia is associated with clinically significant infections and high mortality

    Science.gov (United States)

    Lau, Susanna K. P.; Chow, Wang-Ngai; Foo, Chuen-Hing; Curreem, Shirly O. T.; Lo, George Chi-Shing; Teng, Jade L. L.; Chen, Jonathan H. K.; Ng, Ricky H. Y.; Wu, Alan K. L.; Cheung, Ingrid Y. Y.; Chau, Sandy K. Y.; Lung, David C.; Lee, Rodney A.; Tse, Cindy W. S.; Fung, Kitty S. C.; Que, Tak-Lun; Woo, Patrick C. Y.

    2016-01-01

    Unlike Elizabethkingia meningoseptica, the clinical importance of E. anophelis is poorly understood. We determined the clinical and molecular epidemiology of bacteremia caused by Elizabethkingia-like species from five regional hospitals in Hong Kong. Among 45 episodes of Elizabethkingia-like bacteremia, 21 were caused by Elizabethkingia, including 17 E. anophelis, three E. meningoseptica and one E. miricola; while 24 were caused by other diverse genera/species, as determined by 16S rRNA gene sequencing. Of the 17 cases of E. anophelis bacteremia, 15 (88%) were clinically significant. The most common diagnosis was pneumonia (n = 5), followed by catheter-related bacteremia (n = 4), neonatal meningitis (n = 3), nosocomial bacteremia (n = 2) and neutropenic fever (n = 1). E. anophelis bacteremia was commonly associated with complications and carried 23.5% mortality. In contrast, of the 24 episodes of bacteremia due to non-Elizabethkingia species, 16 (67%) were clinically insignificant. Compared to non-Elizabethkingia bacteremia, Elizabethkingia bacteremia was associated with more clinically significant infections (P < 0.01) and positive cultures from other sites (P < 0.01), less polymicrobial bacteremia (P < 0.01), and higher complication (P < 0.05) and mortality (P < 0.05) rates. Elizabethkingia bacteremia is predominantly caused by E. anophelis instead of E. meningoseptica. Elizabethkingia bacteremia, especially due to E. anophelis, carries significant morbidity and mortality, and should be considered clinically significant unless proven otherwise. PMID:27185741

  13. A severe Morganella morganii endophthalmitis; followed by bacteremia.

    Science.gov (United States)

    Demiray, Tayfur; Aydemir, Ozlem Akkaya; Koroglu, Mehmet; Ozbek, Ahmet; Altindis, Mustafa

    2016-02-01

    Morganella morganii is rarely isolated from nosocomial infections. However, postoperative infections due to Morganella spp. were documented in literature and eye involvements of the infections usually result in severe sequels. We present a severe case infection, which was caused by M. morganii subsp. morganii, firstly appearing as conjunctivitis and complicated by bacteremia. The infectious agent isolated from both conjunctival and consecutive blood cultures. Identification and antimicrobial susceptibility tests were performed with the Vitek 2(®) automated system. The isolate was resistant to cephalosporins and carbapenems and it had ability to produce extended spectrum beta-lactamases. Patient was successfully treated with intravenous ciprofloxacin according to susceptibility test results. This is the first report of M. morganii infection detected as a local infection then complicated by bacteremia.

  14. Risk Factors for Mortality in Patients with Serratia marcescens Bacteremia

    Science.gov (United States)

    Kim, Sun Bean; Jeon, Yong Duk; Kim, Jung Ho; Kim, Jae Kyoung; Ann, Hea Won; Choi, Heun; Kim, Min Hyung; Song, Je Eun; Ahn, Jin Young; Jeong, Su Jin; Han, Sang Hoon; Choi, Jun Yong; Song, Young Goo; Kim, June Myung

    2015-01-01

    Purpose Over the last 30 years, Serratia marcescens (S. marcescens) has emerged as an important pathogen, and a common cause of nosocomial infections. The aim of this study was to identify risk factors associated with mortality in patients with S. marcescens bacteremia. Materials and Methods We performed a retrospective cohort study of 98 patients who had one or more blood cultures positive for S. marcescens between January 2006 and December 2012 in a tertiary care hospital in Seoul, South Korea. Multiple risk factors were compared with association with 28-day all-cause mortality. Results The 28-day mortality was 22.4% (22/98 episodes). In a univariate analysis, the onset of bacteremia during the intensive care unit stay (p=0.020), serum albumin level (p=0.011), serum C-reactive protein level (p=0.041), presence of indwelling urinary catheter (p=0.023), and Sequential Oran Failure Assessment (SOFA) score at the onset of bacteremia (p<0.001) were significantly different between patients in the fatal and non-fatal groups. In a multivariate analysis, lower serum albumin level and an elevated SOFA score were independently associated with 28-day mortality [adjusted odds ratio (OR) 0.206, 95% confidential interval (CI) 0.044-0.960, p=0.040, and adjusted OR 1.474, 95% CI 1.200-1.810, p<0.001, respectively]. Conclusion Lower serum albumin level and an elevated SOFA score were significantly associated with adverse outcomes in patients with S. marcescens bacteremia. PMID:25683980

  15. Meteorological effects on the incidence of pneumococcal bacteremia in Denmark

    DEFF Research Database (Denmark)

    Tvedebrink, Torben; Lundbye-Christensen, Søren; Thomsen, Reimar W.;

    The seasonal nature of invasive pneumococcal disease with peak incidences during winter months is well recognized (Dowell 2003, Talbot 2005, Watson 2006). However few detailed studies of the temporal relationship between actual climatic changes and subsequent pneumococcal disease are available. We...... perform an 8-year longitudinal population-based ecological study in a Danish county to examine whether foregoing changes in meteorological parameters, including temperature, relative humidity, precipitation, and wind velocity, predicted variations in pneumococcal bacteremia (PB) incidence....

  16. Stevioside plays an anti-inflammatory role by regulating the NF-κB and MAPK pathways in S. aureus-infected mouse mammary glands.

    Science.gov (United States)

    Wang, Tiancheng; Guo, Mengyao; Song, Xiaojing; Zhang, Zecai; Jiang, Haichao; Wang, Wei; Fu, Yunhe; Cao, Yongguo; Zhu, Lianqin; Zhang, Naisheng

    2014-10-01

    Mastitis is an inflammatory disease caused by microbial infection. Staphylococcus aureus is one of the primary bacteria responsible for mastitis. Stevioside is isolated from Stevia rebaudiana and is known to have therapeutic functions. This study was designed to evaluate the effects of stevioside in a mouse model of S. aureus-induced mastitis. In this study, the mouse mammary gland was infected with S. aureus to induce the mastitis model. The stevioside was administered intraperitoneally after the S. aureus infection was established. Hematoxylin-eosin (HE) staining, ELISA, Western blot, and q-PCR methods were used. The results show that stevioside significantly reduced the inflammatory cell infiltration and the levels of TNF-α, IL-1β, and IL-6 and the respective expression of their messenger RNAs (mRNAs). Further studies revealed that stevioside downregulated the TLR2, NF-κB, and (mitogen-activated protein kinase) MAPK signaling pathways in the S. aureus-infected mouse mammary gland. Our results demonstrate that stevioside reduced the expression of TNF-α, IL-1β, and IL-6 by inhibiting the phosphorylation of proteins in the NF-κB and MAPK signaling pathways dose-dependently, but that their mRNA expression was not obviously changed. PMID:24858724

  17. Brazilin plays an anti-inflammatory role with regulating Toll-like receptor 2 and TLR 2 downstream pathways in Staphylococcus aureus-induced mastitis in mice.

    Science.gov (United States)

    Gao, Xue-jiao; Wang, Tian-cheng; Zhang, Ze-cai; Cao, Yong-guo; Zhang, Nai-sheng; Guo, Meng-yao

    2015-07-01

    Mastitis, which commonly occurs during the postpartum period, is caused by the infection of the mammary glands. The most common infectious bacterial pathogen of mastitis is Staphylococcus aureus (S. aureus) in both human and animals. Brazilin, a compound isolated from the traditional herbal medicine Caesalpinia sappan L., has been shown to exhibit multiple biological properties. The present study was performed to determine the effect of brazilin on the inflammatory response in the mouse model of S. aureus mastitis and to confirm the mechanism of action involved. Brazilin treatment was applied in both a mouse model and cells. After brazilin treatment of cells, Western blotting and qPCR were performed to detect the protein levels and mRNA levels, respectively. Brazilin treatment significantly attenuated inflammatory cell infiltration and inhibited the expressions of TNF-α, IL-1β and IL-6 in a dose-dependent manner. Administration of brazilin in mice suppressed S. aureus-induced inflammatory injury and the production of proinflammatory mediators. This suppression was achieved by reducing the increased expression of TLR2 and regulating the NF-κB and MAPK signaling pathways in the mammary gland tissues and cells with S. aureus-induced mastitis. These results suggest that brazilin appears to be an effective drug for the treatment of mastitis and may be applied as a clinical therapy.

  18. Cadmium-induced accumulation of hydrogen peroxide in the leaf apoplast of Phaseolus aureus and Vicia sativa and the roles of different antioxidant enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Fenqin [Department of Life Science and Engineering, Hexi University, Zhangye 734000 (China); Zhang Hongxiao; Wang Guiping; Xu Langlai [College of Life Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Shen Zhenguo, E-mail: zgshen@njau.edu.cn [College of Life Sciences, Nanjing Agricultural University, Nanjing 210095 (China)

    2009-08-30

    The effects of cadmium (Cd) on the accumulation of hydrogen peroxide (H{sub 2}O{sub 2}) and superoxide anion (O{sub 2}{center_dot}{sup -}) in leaves of Phaseolus aureus and Vicia sativa were investigated. Cadmium at 100 {mu}M significantly increased the production of O{sub 2}{center_dot}{sup -} and H{sub 2}O{sub 2}, as well as the activities of plasma membrane-bound nicotinamide adenine dinucleotide phosphate (NADPH) oxidases and the symplastic and apoplastic activities of superoxide dismutase and ascorbate peroxidase in the leaves of both species. Apoplastic guaiacol peroxidase activity was significantly induced in the leaves of both species, particularly in P. aureus exposed to 100 {mu}M Cd. Experiments with diphenylene iodonium as an inhibitor of NADPH oxidase and NaN{sub 3} as an inhibitor of peroxidase showed that the majority of Cd-induced reactive oxygen species production in the leaves of both species may involve plasma membrane-bound NADPH oxidase and apoplastic peroxidase. Compared to V. sativa, increases in Cd-induced production of O{sub 2}{center_dot}{sup -} and H{sub 2}O{sub 2} and activities of NADPH oxidase and apoplastic peroxidase were more pronounced in P. aureus. In contrast, V. sativa had higher leaf symplastic superoxide dismutase and ascorbate peroxidase activities than P. aureus. The results indicated that V. sativa was more tolerant to Cd than P. aureus.

  19. Cadmium-induced accumulation of hydrogen peroxide in the leaf apoplast of Phaseolus aureus and Vicia sativa and the roles of different antioxidant enzymes

    International Nuclear Information System (INIS)

    The effects of cadmium (Cd) on the accumulation of hydrogen peroxide (H2O2) and superoxide anion (O2·-) in leaves of Phaseolus aureus and Vicia sativa were investigated. Cadmium at 100 μM significantly increased the production of O2·- and H2O2, as well as the activities of plasma membrane-bound nicotinamide adenine dinucleotide phosphate (NADPH) oxidases and the symplastic and apoplastic activities of superoxide dismutase and ascorbate peroxidase in the leaves of both species. Apoplastic guaiacol peroxidase activity was significantly induced in the leaves of both species, particularly in P. aureus exposed to 100 μM Cd. Experiments with diphenylene iodonium as an inhibitor of NADPH oxidase and NaN3 as an inhibitor of peroxidase showed that the majority of Cd-induced reactive oxygen species production in the leaves of both species may involve plasma membrane-bound NADPH oxidase and apoplastic peroxidase. Compared to V. sativa, increases in Cd-induced production of O2·- and H2O2 and activities of NADPH oxidase and apoplastic peroxidase were more pronounced in P. aureus. In contrast, V. sativa had higher leaf symplastic superoxide dismutase and ascorbate peroxidase activities than P. aureus. The results indicated that V. sativa was more tolerant to Cd than P. aureus.

  20. High MICs for Vancomycin and Daptomycin and Complicated Catheter-Related Bloodstream Infections with Methicillin-Sensitive Staphylococcus aureus

    Science.gov (United States)

    Viedma, Esther; Chaves, Fernando; Lalueza, Antonio; Fortún, Jesús; Loza, Elena; Pujol, Miquel; Ardanuy, Carmen; Morales, Isabel; de Cueto, Marina; Resino-Foz, Elena; Morales-Cartagena, Alejandra; Rico, Alicia; Romero, María P.; Orellana, María Ángeles; López-Medrano, Francisco; Fernández-Ruiz, Mario; Aguado, José María

    2016-01-01

    We investigated the prognostic role of high MICs for antistaphylococcal agents in patients with methicillin-sensitive Staphylococcus aureus catheter-related bloodstream infection (MSSA CRBSI). We prospectively reviewed 83 episodes from 5 centers in Spain during April 2011–June 2014 that had optimized clinical management and analyzed the relationship between E-test MICs for vancomycin, daptomycin, oxacillin, and linezolid and development of complicated bacteremia by using multivariate analysis. Complicated MSSA CRBSI occurred in 26 (31.3%) patients; MICs for vancomycin and daptomycin were higher in these patients (optimal cutoff values for predictive accuracy = 1.5 μg/mL and 0.5 μg/mL). High MICs for vancomycin (hazard ratio 2.4, 95% CI 1.2–5.5) and daptomycin (hazard ratio 2.4, 95% CI 1.1–5.9) were independent risk factors for development of complicated MSSA CRBSI. Our data suggest that patients with MSSA CRBSI caused by strains that have high MICs for vancomycin or daptomycin are at increased risk for complications. PMID:27192097

  1. 金黄色葡萄球菌SarS蛋白参与压力应激的初步研究%SarS protein plays a role in stress response in Staphylococcus aureus

    Institute of Scientific and Technical Information of China (English)

    谭小蓉; 刘玉; 牟春花; 高亚萍; 董洁; 杨光

    2013-01-01

    Objective To investigate the regulatory function of Staphylococcus aureus accessory regulator S (SarS) protein in 5. aureus via insertion mutant construction. Methods The sarS inactive mutant was constructed by homologous re -combination in 5. aureus 8325 -4. The level of extra-toxins production was detected in MDBK cells , and the growth curves under different stress conditions were measured . Results The sarS mutant was successfully constructed in 5. aureus 8325 -4. Compared with its parent strain , the level of extra-toxins and the growth of the sarS mutant were not altered. However, it was found that the growth rate of sarS mutant was significantly decreased under several stress conditions compared with its parent strain. Conclusion SarS plays an important role in stress responses in 5. aureus.%目的 通过构建金黄色葡萄球菌(Staphylococcus aureus,简称金葡菌)中SarS蛋白突变株,研究SarS蛋白在金葡菌中的调控功能.方法 利用同源重组的方法构建金葡菌8325-4来源的sarS插入突变菌株,通过MDBK细胞模型检测突变株外毒素水平,以及其在高盐、高温等条件下的生长情况.结果 成功构建了金葡菌8325-4来源的sarS插入突变菌株.进一步的表型检测结果显示,与野生型菌株相比,sarS突变株在高温、高渗、重金属等应激条件下的生长速度明显下降,但是细菌外毒素对MDBK细胞的杀伤作用没有明显的改变.结论 SarS蛋白在金葡菌抵抗外界压力应激中发挥着重要的功能.

  2. Identification of Infantile Diarrhea Caused by Breast Milk-Transmitted Staphylococcus aureus Infection.

    Science.gov (United States)

    Chen, Zhong; Pan, Wei-Guang; Xian, Wei-Yi; Cheng, Hang; Zheng, Jin-Xin; Hu, Qing-Hua; Yu, Zhi-Jian; Deng, Qi-Wen

    2016-10-01

    Staphylococcus aureus is a well-known organism which is responsible for a variety of human infectious diseases including skin infections, pneumonia, bacteremia, and endocarditis. Few of the microorganisms can be transmitted from mother to the newborn or infant by milk breastfeeding. This study aims to identify transmission of S. aureus from healthy, lactating mothers to their infants by breastfeeding. Stool specimens of diarrheal infants and breast milk of their mother (totally three pairs) were collected and six Staphylococcus aureus isolates were cultured positively. Homology and molecular characters of isolated strains were tested using pulsed-field gel electrophoresis (PFGE), spa typing, and multilocus sequence typing. Furthermore, toxin genes detection was also performed. Each pair of isolates has the same PFGE type and spa type. Four Sequence types (STs) were found among all the isolates; they are ST15, ST188, and ST59, respectively. Among the strains, seb, sec, and tst genes were found, and all were negative for pvl gene. The homology of the S. aureus strains isolated from the infants' stool and the mothers' milk was genetically demonstrated, which indicated that breastfeeding may be important in the transmission of S. aureus infection, and the character of S. aureus needed to be further evaluated. PMID:27344596

  3. Persistent Bacillus cereus Bacteremia in 3 Persons Who Inject Drugs, San Diego, California, USA.

    Science.gov (United States)

    Schaefer, Gabrielle; Campbell, Wesley; Jenks, Jeffrey; Beesley, Cari; Katsivas, Theodoros; Hoffmaster, Alex; Mehta, Sanjay R; Reed, Sharon

    2016-09-01

    Bacillus cereus is typically considered a blood culture contaminant; however, its presence in blood cultures can indicate true bacteremia. We report 4 episodes of B. cereus bacteremia in 3 persons who inject drugs. Multilocus sequence typing showed that the temporally associated infections were caused by unrelated clones. PMID:27533890

  4. Treatment of Haemophilus bacteremia with benzylpenicillin is associated with increased (30-day) mortality

    DEFF Research Database (Denmark)

    Thønnings, Sara; Andersen, Christian Østergaard

    2012-01-01

    Optimal antibiotic treatment strategies of Haemophilus infections are still needed. Therefore, 30-day case fatality rate (CFR) of Haemophilus bacteremia and efficacy of various antibiotic treatment regimes were studied.......Optimal antibiotic treatment strategies of Haemophilus infections are still needed. Therefore, 30-day case fatality rate (CFR) of Haemophilus bacteremia and efficacy of various antibiotic treatment regimes were studied....

  5. Epidemiology, Management, and Risk-Adjusted Mortality of ICU-Acquired Enterococcal Bacteremia.

    NARCIS (Netherlands)

    Ong, David S Y; Bonten, Marc J M; Safdari, Khatera; Spitoni, Cristian; Frencken, Jos F; Witteveen, Esther; Horn, Janneke; Klein Klouwenberg, Peter M C; Cremer, Olaf L

    2015-01-01

    BACKGROUND: Enterococcal bacteremia has been associated with high case fatality, but it remains unknown to what extent death is caused by these infections. We therefore quantified attributable mortality of intensive care unit (ICU)-acquired bacteremia caused by enterococci. METHODS: From 2011 to 201

  6. Epidemiology, Management, and Risk-Adjusted Mortality of ICU-Acquired Enterococcal Bacteremia

    NARCIS (Netherlands)

    Ong, David S Y; Bonten, Marc J M; Safdari, Khatera; Spitoni, Cristian; Frencken, Jos F; Witteveen, Esther; Horn, Janneke; Klein Klouwenberg, Peter M C; Cremer, Olaf L

    2015-01-01

    BACKGROUND:  Enterococcal bacteremia has been associated with high case fatality, but it remains unknown to what extent death is caused by these infections. We therefore quantified attributable mortality of intensive care unit (ICU)-acquired bacteremia caused by enterococci. METHODS:  From 2011 to 2

  7. Chronic Liver Disease Impairs Bacterial Clearance in a Human Model of Induced Bacteremia

    OpenAIRE

    Ashare, Alix; Stanford, Clark; Hancock, Patricia; Stark, Donna; Lilli, Kathleen; Birrer, Emily; Nymon, Amanda; Doerschug, Kevin C.; Hunninghake, Gary W.

    2009-01-01

    Sepsis often causes impaired hepatic function. Patients with liver disease have an increased risk of bacteremia. This is thought to be secondary to impaired reticuloendothelial system function. However, this has not been demonstrated clinically. Since transient bacteremia occurs following toothbrushing, we hypothesized that subjects with cirrhosis would have impaired bacterial clearance following toothbrushing compared with subjects with pulmonary disease and healthy controls. After baseline ...

  8. Invasive Community-Acquired Methicillin-Resistant Staphylococcus aureus in a Japanese Girl with Disseminating Multiple Organ Infection: A Case Report and Review of Japanese Pediatric Cases

    OpenAIRE

    Ryuta Yonezawa; Tsukasa Kuwana; Kengo Kawamura; Yasuji Inamo

    2015-01-01

    Pediatric invasive community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infection is very serious and occasionally fatal. This infectious disease is still a relatively rare and unfamiliar infectious disease in Japan. We report a positive outcome in a 23-month-old Japanese girl with meningitis, osteomyelitis, fasciitis, necrotizing pneumonia, urinary tract infection, and bacteremia due to CA-MRSA treated with linezolid. PCR testing of the CA-MRSA strain was positive for PVL...

  9. C-reactive protein level as a predictor of mortality in liver disease patients with bacteremia

    DEFF Research Database (Denmark)

    Janum, Sine H; Søvsø, Morten; Gradel, Kim O;

    2011-01-01

    Abstract Background and objective. C-reactive protein (CRP) is synthesized in the liver in response to inflammation, and CRP is a widely used marker of sepsis. In bacteremia the initial CRP level is an independent predictor of mortality. Since the CRP response in patients with chronic liver disease...... was observed. Conclusion. Mortality associated with bacteremia is increased in patients with chronic liver disease and it is correlated with Child-Turcotte-Pugh score. The prognostic information of initial CRP levels in patients with chronic liver disease is weak. The clinical management of patients...... is lower than in patients without liver disease the objective was to assess whether CRP levels in chronic liver disease and bacteremia was associated with case fatality. Patients. The study enrolled 105 patients with chronic liver disease and bacteremia as well as 202 patients with bacteremia...

  10. Bacteremia with Streptococcus bovis and Streptococcus salivarius: clinical correlates of more accurate identification of isolates.

    Science.gov (United States)

    Ruoff, K L; Miller, S I; Garner, C V; Ferraro, M J; Calderwood, S B

    1989-01-01

    Two biotypes of Streptococcus bovis can be identified by laboratory testing and can be distinguished from the phenotypically similar organism Streptococcus salivarius. We assessed the clinical relevance of careful identification of these organisms in 68 patients with streptococcal bacteremia caused by these similar species. S. bovis was more likely to be clinically significant when isolated from blood (89%) than was S. salivarius (23%). There was a striking association between S. bovis I bacteremia and underlying endocarditis (94%) compared with that of S. bovis II bacteremia (18%). Bacteremia with S. bovis I was also highly correlated with an underlying colonic neoplasm (71% of patients overall, 100% of those with thorough colonic examinations) compared with bacteremia due to S. bovis II or S. salivarius (17% overall, 25% of patients with thorough colonic examinations). We conclude that careful identification of streptococcal bacteremic isolates as S. bovis biotype I provides clinically important information and should be more widely applied. PMID:2915024

  11. Prevalence of clonal complexes and virulence genes among commensal and invasive Staphylococcus aureus isolates in Sweden.

    Directory of Open Access Journals (Sweden)

    Gunlög Rasmussen

    Full Text Available Staphylococcus aureus encodes a remarkable number of virulence factors which may contribute to its pathogenicity and ability to cause invasive disease. The main objective of this study was to evaluate the association between S. aureus invasiveness and bacterial genotype, in terms of the presence of virulence genes and affiliation to clonal complexes. Also, the significance of different virulence genes, mainly adhesins, for the development of infective endocarditis was investigated. DNA microarray technology was used to analyze 134 S. aureus isolates, all methicillin-susceptible, derived from three groups of clinically well-characterized patients: nasal carriers (n=46, bacteremia (n=55, and bacteremia with infective endocarditis (n=33. Invasive isolates were dominant in four of the major clonal complexes: 5, 8, 15, and 25. Of the 170 virulence genes examined, those encoding accessory gene regulator group II (agr II, capsule polysaccharide serotype 5 (cap5, and adhesins such as S. aureus surface protein G (sasG and fibronectin-binding protein B (fnbB were found to be associated with invasive disease. The same was shown for the leukocidin genes lukD/lukE, as well as the genes encoding serine protease A and B (splA/splB, staphylococcal complement inhibitor (scn and the staphylococcal exotoxin-like protein (setC or selX. In addition, there was a trend of higher prevalence of certain genes or gene clusters (sasG, agr II, cap5 among isolates causing infective endocarditis compared to other invasive isolates. In most cases, the presence of virulence genes was linked to clonal complex affiliation. In conclusion, certain S. aureus clonal lineages harboring specific sets of virulence genes seem to be more successful in causing invasive disease.

  12. Anaerobic Bacteremia: Impact of Inappropriate Therapy on Mortality

    Science.gov (United States)

    Lee, Yangsoon; Park, Yongjung; Kim, Myungsook; Choi, Jun Yong; Yong, Dongeun; Jeong, Seok Hoon

    2016-01-01

    Background Investigation on incidence and mortality of anaerobic bacteremia (AB) is clinically relevant in spite of its infrequent occurrence and not often explored, which report varies according to period and institutions. Therefore, it is necessary to analyze the incidence and risk factors related to mortality and assess clinical outcomes of AB in current aspect. Materials and Methods Characteristics of AB patients and anaerobic bacteria from blood culture at a university hospital in 2012 were reviewed retrospectively. The correlation between risk factors and 28-day patient mortality was analyzed. Results A total of 70 non-duplicated anaerobic bacteria were isolated from blood of 70 bacteremia patients in 2012. The history of cardiovascular disease as host's risk factor was statistically significant (P = 0.0344) in univariate and multivariate analysis. Although the inappropriate therapy was not statistically significant in univariate and multivariate analysis, the survival rate of bacteremia was significantly worse in patients who had inappropriate therapy compared with those underwent appropriate therapy (hazard ratio, 5.4; 95% confidence interval, 1.7–6.9; P = 0.004). The most frequently isolated organism was Bacteroides fragilis (32 isolates, 46%), followed by Bacteroides thetaiotaomicron (10, 14%), and non-perfringens Clostridium (7, 10%). Conclusion The incidence of AB in 2012 was 2.3% (number of AB patients per 100 positive blood culture patients) and the mortality rate in patients with clinically significant AB was 21.4%. In addition, AB was frequently noted in patients having malignancy and the survival rate of AB was significantly worse in patients who received inappropriate therapy compared with those underwent appropriate therapy. PMID:27433379

  13. A Case of Liver Abscess with Desulfovibrio desulfuricans Bacteremia

    Directory of Open Access Journals (Sweden)

    Saho Koyano

    2015-01-01

    Full Text Available Desulfovibrio spp. are gram-negative, sulfate-reducing, and anaerobic bacteria found in the digestive tract of humans. Because Desulfovibrio spp. are infrequent causative agents of infectious diseases and are difficult to isolate and to identify from clinical specimens, the appropriate antibiotic therapy to infection with Desulfovibrio spp. has not been determined. We report the first case of liver abscess with bacteremia due to Desulfovibrio desulfuricans to show the clinical presentation and treatment. The patient was successfully treated with intravenous piperacillin-tazobactam and oral amoxicillin-clavulanic acid.

  14. Potassium Uptake Modulates Staphylococcus aureus Metabolism.

    Science.gov (United States)

    Gries, Casey M; Sadykov, Marat R; Bulock, Logan L; Chaudhari, Sujata S; Thomas, Vinai C; Bose, Jeffrey L; Bayles, Kenneth W

    2016-01-01

    As a leading cause of community-associated and nosocomial infections, Staphylococcus aureus requires sophisticated mechanisms that function to maintain cellular homeostasis in response to its exposure to changing environmental conditions. The adaptation to stress and maintenance of homeostasis depend largely on membrane activity, including supporting electrochemical gradients and synthesis of ATP. This is largely achieved through potassium (K(+)) transport, which plays an essential role in maintaining chemiosmotic homeostasis, affects antimicrobial resistance, and contributes to fitness in vivo. Here, we report that S. aureus Ktr-mediated K(+) uptake is necessary for maintaining cytoplasmic pH and the establishment of a proton motive force. Metabolite analyses revealed that K(+) deficiency affects both metabolic and energy states of S. aureus by impairing oxidative phosphorylation and directing carbon flux toward substrate-level phosphorylation. Taken together, these results underline the importance of K(+) uptake in maintaining essential components of S. aureus metabolism. IMPORTANCE Previous studies describing mechanisms for K(+) uptake in S. aureus revealed that the Ktr-mediated K(+) transport system was required for normal growth under alkaline conditions but not under neutral or acidic conditions. This work focuses on the effect of K(+) uptake on S. aureus metabolism, including intracellular pH and carbon flux, and is the first to utilize a pH-dependent green fluorescent protein (GFP) to measure S. aureus cytoplasmic pH. These studies highlight the role of K(+) uptake in supporting proton efflux under alkaline conditions and uncover a critical role for K(+) uptake in establishing efficient carbon utilization. PMID:27340697

  15. Staphylococcus aureus and the ecology of the nasal microbiome

    DEFF Research Database (Denmark)

    Liu, Cindy M; Price, Lance B; Hungate, Bruce A;

    2015-01-01

    The human microbiome can play a key role in host susceptibility to pathogens, including in the nasal cavity, a site favored by Staphylococcus aureus. However, what determines our resident nasal microbiota-the host or the environment-and can interactions among nasal bacteria determine S. aureus...

  16. Staphylococcus aureus Bacteraemia

    Directory of Open Access Journals (Sweden)

    James Price

    2010-01-01

    Full Text Available Staphylococcus aureus bacteraemia (SAB is commonly complicated by metastatic infection or relapse after treatment. Objectives. The study aim was to determine the role of bacterial, host, and management factors in development of complicated SAB. Methods. A prospectively-conducted observational study gathered data on predisposition, management and outcome of 100 consecutive SAB cases. Antibiotic susceptibilities and genetic lineage of bacterial isolates were determined. Further clinical and microbiological data were gathered on two retrospective series from 1999–2000 (n=57 and 2004 (n=116. Results. In the prospective cases, 27% met our definition of complicated disease. Expressed as RR and 95% CI, complicated disease was associated with diabetes (1.58, 1.00–2.48, injecting-drug use (5.48, 0.88–33.49, community-onset of symptoms (1.4, 1.02–1.92, and symptom duration ≥48 hours prior to starting effective antibiotic therapy (2.10, 1.22–3.61. Uncomplicated disease was associated with the presence of a central line (0.69, 0.55–0.88 and prompt removal of a primary focus (0.71, 0.57–0.90. Neither methicillin resistance nor genetic lineage was associated with complicated disease, but methicillin resistance was associated with higher mortality. Conclusions. This study demonstrates that clinical rather than microbial factors are the major determinants of SAB outcome and underscores the importance of early treatment.

  17. Impact of the Regulators SigB, Rot, SarA and sarS on the Toxic Shock Tst Promoter and TSST-1 Expression in Staphylococcus aureus.

    Science.gov (United States)

    Andrey, Diego O; Jousselin, Ambre; Villanueva, Maite; Renzoni, Adriana; Monod, Antoinette; Barras, Christine; Rodriguez, Natalia; Kelley, William L

    2015-01-01

    Staphylococcus aureus is an important pathogen manifesting virulence through diverse disease forms, ranging from acute skin infections to life-threatening bacteremia or systemic toxic shock syndromes. In the latter case, the prototypical superantigen is TSST-1 (Toxic Shock Syndrome Toxin 1), encoded by tst(H), and carried on a mobile genetic element that is not present in all S. aureus strains. Transcriptional regulation of tst is only partially understood. In this study, we dissected the role of sarA, sarS (sarH1), RNAIII, rot, and the alternative stress sigma factor sigB (σB). By examining tst promoter regulation predominantly in the context of its native sequence within the SaPI1 pathogenicity island of strain RN4282, we discovered that σB emerged as a particularly important tst regulator. We did not detect a consensus σB site within the tst promoter, and thus the effect of σB is likely indirect. We found that σB strongly repressed the expression of the toxin via at least two distinct regulatory pathways dependent upon sarA and agr. Furthermore rot, a member of SarA family, was shown to repress tst expression when overexpressed, although its deletion had no consistent measurable effect. We could not find any detectable effect of sarS, either by deletion or overexpression, suggesting that this regulator plays a minimal role in TSST-1 expression except when combined with disruption of sarA. Collectively, our results extend our understanding of complex multifactorial regulation of tst, revealing several layers of negative regulation. In addition to environmental stimuli thought to impact TSST-1 production, these findings support a model whereby sporadic mutation in a few key negative regulators can profoundly affect and enhance TSST-1 expression. PMID:26275216

  18. Impact of the Regulators SigB, Rot, SarA and sarS on the Toxic Shock Tst Promoter and TSST-1 Expression in Staphylococcus aureus.

    Directory of Open Access Journals (Sweden)

    Diego O Andrey

    Full Text Available Staphylococcus aureus is an important pathogen manifesting virulence through diverse disease forms, ranging from acute skin infections to life-threatening bacteremia or systemic toxic shock syndromes. In the latter case, the prototypical superantigen is TSST-1 (Toxic Shock Syndrome Toxin 1, encoded by tst(H, and carried on a mobile genetic element that is not present in all S. aureus strains. Transcriptional regulation of tst is only partially understood. In this study, we dissected the role of sarA, sarS (sarH1, RNAIII, rot, and the alternative stress sigma factor sigB (σB. By examining tst promoter regulation predominantly in the context of its native sequence within the SaPI1 pathogenicity island of strain RN4282, we discovered that σB emerged as a particularly important tst regulator. We did not detect a consensus σB site within the tst promoter, and thus the effect of σB is likely indirect. We found that σB strongly repressed the expression of the toxin via at least two distinct regulatory pathways dependent upon sarA and agr. Furthermore rot, a member of SarA family, was shown to repress tst expression when overexpressed, although its deletion had no consistent measurable effect. We could not find any detectable effect of sarS, either by deletion or overexpression, suggesting that this regulator plays a minimal role in TSST-1 expression except when combined with disruption of sarA. Collectively, our results extend our understanding of complex multifactorial regulation of tst, revealing several layers of negative regulation. In addition to environmental stimuli thought to impact TSST-1 production, these findings support a model whereby sporadic mutation in a few key negative regulators can profoundly affect and enhance TSST-1 expression.

  19. Impact of the Regulators SigB, Rot, SarA and sarS on the Toxic Shock Tst Promoter and TSST-1 Expression in Staphylococcus aureus.

    Science.gov (United States)

    Andrey, Diego O; Jousselin, Ambre; Villanueva, Maite; Renzoni, Adriana; Monod, Antoinette; Barras, Christine; Rodriguez, Natalia; Kelley, William L

    2015-01-01

    Staphylococcus aureus is an important pathogen manifesting virulence through diverse disease forms, ranging from acute skin infections to life-threatening bacteremia or systemic toxic shock syndromes. In the latter case, the prototypical superantigen is TSST-1 (Toxic Shock Syndrome Toxin 1), encoded by tst(H), and carried on a mobile genetic element that is not present in all S. aureus strains. Transcriptional regulation of tst is only partially understood. In this study, we dissected the role of sarA, sarS (sarH1), RNAIII, rot, and the alternative stress sigma factor sigB (σB). By examining tst promoter regulation predominantly in the context of its native sequence within the SaPI1 pathogenicity island of strain RN4282, we discovered that σB emerged as a particularly important tst regulator. We did not detect a consensus σB site within the tst promoter, and thus the effect of σB is likely indirect. We found that σB strongly repressed the expression of the toxin via at least two distinct regulatory pathways dependent upon sarA and agr. Furthermore rot, a member of SarA family, was shown to repress tst expression when overexpressed, although its deletion had no consistent measurable effect. We could not find any detectable effect of sarS, either by deletion or overexpression, suggesting that this regulator plays a minimal role in TSST-1 expression except when combined with disruption of sarA. Collectively, our results extend our understanding of complex multifactorial regulation of tst, revealing several layers of negative regulation. In addition to environmental stimuli thought to impact TSST-1 production, these findings support a model whereby sporadic mutation in a few key negative regulators can profoundly affect and enhance TSST-1 expression.

  20. Is nosocomial Escherichia coli bacteremia a predictive risk factor for mortality?

    Directory of Open Access Journals (Sweden)

    Felipe F. Tuon

    2014-01-01

    Full Text Available The objective of this study was to determine risk factors associated with mortality in patients with nosocomial Escherichia coli bacteremia from January 2009 to January 2011. In a retrospective study the medical records of 88 patients over 18 years with nosocomial bacteremia caused by E. coli were analyzed. In univariate analysis several risk factors, including chronic renal failure, altered mental status, leukocytosis, and higher Charlson index of comorbidities were associated with mortality. In multivariate analysis only altered mental status remained independently associated with mortality. Mental confusion can be a risk factor for mortality in patients with E. coli bacteremia.

  1. Staphylococcus saprophyticus Bacteremia originating from Urinary Tract Infections: A Case Report and Literature Review

    Science.gov (United States)

    Lee, Anna; Hong, Jeongmin; Jo, Won-yong; Cho, Oh-Hyun; Kim, Sunjoo

    2016-01-01

    Staphylococcus saprophyticus is a common pathogen of acute urinary tract infection (UTI) in young females. However, S. saprophyticus bacteremia originating from UTI is very rare and has not been reported in Korea. We report a case of S. saprophyticus bacteremia from UTI in a 60-year-old female with a urinary stone treated successfully with intravenous ciprofloxacin, and review the cases of S. saprophyticus bacteremia reported in the literature. Thus, the microorganism may cause invasive infection and should be considered when S. saprophyticus is isolated from blood cultures in patients with UTI.

  2. Acute Hemolysis with Renal Failure due to Clostridium Bacteremia in a Patient with AML

    Science.gov (United States)

    Medrano-Juarez, R. M.; Sotello, D.; D'Cuhna, L.; Payne, J. D.

    2016-01-01

    We present a case of acute hemolytic anemia, renal failure, and Clostridium perfringens bacteremia in a patient with acute myelogenous leukemia. The high fatality of C. perfringens bacteremia requires that clinicians recognize and rapidly treat patients at risk for this infection. Although other hemolytic processes are in the differential diagnosis of these events, the presence of high fever, chills, and rapidly positive blood cultures may help narrow the diagnosis. Most cases of C. perfringens bacteremia have a concomitant coinfection, which makes broad spectrum empiric therapy essential. There is a high mortality rate of C. perfringens infections associated with leukemia.

  3. Staphylococcus saprophyticus Bacteremia originating from Urinary Tract Infections: A Case Report and Literature Review.

    Science.gov (United States)

    Hur, Jaehyung; Lee, Anna; Hong, Jeongmin; Jo, Won-Yong; Cho, Oh-Hyun; Kim, Sunjoo; Bae, In-Gyu

    2016-06-01

    Staphylococcus saprophyticus is a common pathogen of acute urinary tract infection (UTI) in young females. However, S. saprophyticus bacteremia originating from UTI is very rare and has not been reported in Korea. We report a case of S. saprophyticus bacteremia from UTI in a 60-year-old female with a urinary stone treated successfully with intravenous ciprofloxacin, and review the cases of S. saprophyticus bacteremia reported in the literature. Thus, the microorganism may cause invasive infection and should be considered when S. saprophyticus is isolated from blood cultures in patients with UTI.

  4. Staphylococcus saprophyticus Bacteremia originating from Urinary Tract Infections: A Case Report and Literature Review.

    Science.gov (United States)

    Hur, Jaehyung; Lee, Anna; Hong, Jeongmin; Jo, Won-Yong; Cho, Oh-Hyun; Kim, Sunjoo; Bae, In-Gyu

    2016-06-01

    Staphylococcus saprophyticus is a common pathogen of acute urinary tract infection (UTI) in young females. However, S. saprophyticus bacteremia originating from UTI is very rare and has not been reported in Korea. We report a case of S. saprophyticus bacteremia from UTI in a 60-year-old female with a urinary stone treated successfully with intravenous ciprofloxacin, and review the cases of S. saprophyticus bacteremia reported in the literature. Thus, the microorganism may cause invasive infection and should be considered when S. saprophyticus is isolated from blood cultures in patients with UTI. PMID:27433385

  5. Daptomycin approved in Japan for the treatment of methicillin-resistant Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Mori T

    2012-02-01

    Full Text Available Mao Hagihara1, Takumi Umemura1, Takeshi Mori1,2, Hiroshige Mikamo11Department of Infection Control and Prevention, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan; 2Division of Pharmaceutical Science, Faculty of Pharmacy, Meijo University, Nagoya, Aichi, JapanAbstract: Daptomycin is a lipoglycopeptide antibacterial drug that is rapidly bactericidal for methicillin-resistant Staphylococcus aureus (MRSA infection and has antibiotic activity against a wide range of Gram-positive organisms. It has been approved by the Ministry of Health, Labor and Welfare in Japan for the treatment for bacteremia, right-sided endocarditis, and skin and skin-structure infections, such as necrotizing fasciitis, due to MRSA on the basis of a Phase III trial conducted in Japan since July, 2011. In Japanese Phase I and III trials, daptomycin therapy given at 4 mg/kg and 6 mg/kg once per day was well tolerated and effective as standard therapy for the treatment of acute bacterial skin and skin-structure infections and bacteremia caused by MRSA, but side effects remain to be evaluated in large-scale trials.Keywords: daptomycin, methicillin-resistant Staphylococcus aureus (MRSA, Japan

  6. A Propensity Score Analysis Shows that Empirical Treatment with Linezolid Does Not Increase the Thirty-Day Mortality Rate in Patients with Gram-Negative Bacteremia

    Science.gov (United States)

    Ternavasio-de la Vega, Hugo-Guillermo; Mateos-Díaz, Ana-María; Martinez, Jose-Antonio; Almela, Manel; Cobos-Trigueros, Nazaret; Morata, Laura; De-la-Calle, Cristina; Sala, Marta; Mensa, Josep; Soriano, Alex

    2014-01-01

    The role of linezolid in empirical therapy of suspected bacteremia remains unclear. The aim of this study was to evaluate the influence of empirical use of linezolid or glycopeptides in addition to other antibiotics on the 30-day mortality rates in patients with Gram-negative bacteremia. For this purpose, 1,126 patients with Gram-negative bacteremia in the Hospital Clinic of Barcelona from 2000 to 2012 were included in this study. In order to compare the mortality rates between patients who received linezolid or glycopeptides, the propensity scores on baseline variables were used to balance the treatment groups, and both propensity score matching and propensity-adjusted logistic regression were used to compare the 30-day mortality rates between the groups. The overall 30-day mortality rate was 16.0% during the study period. Sixty-eight patients received empirical treatment with linezolid, and 1,058 received glycopeptides. The propensity score matching included 64 patients in each treatment group. After matching, the mortality rates were 14.1% (9/64) in patients who received glycopeptides and 21.9% (14/64) in those who received linezolid, and a nonsignificant association between empirical linezolid treatment and mortality rate (odds ratio [OR], 1.63; 95% confidence interval [CI], 0.69 to 3.82; P = 0.275, McNemar's test) was found. This association remained nonsignificant when variables that remained unbalanced after matching were included in a conditional logistic regression model. Further, the stratified propensity score analysis did not show any significant relationship between empirical linezolid treatment and the mortality rate after adjustment by propensity score quintiles or other variables potentially associated with mortality. In conclusion, the propensity score analysis showed that empirical treatment with linezolid compared with that with glycopeptides was not associated with 30-day mortality rates in patients with Gram-negative bacteremia. PMID:25199780

  7. The Stealthy Superbug: the Role of Asymptomatic Enteric Carriage in Maintaining a Long-Term Hospital Outbreak of ST228 Methicillin-Resistant Staphylococcus aureus

    OpenAIRE

    Senn, Laurence; Clerc, Olivier; Zanetti, Giorgio; Basset, Patrick; Prod’Hom, Guy; Gordon, Nicola C.; Sheppard, Anna E.; Crook, Derrick W; James, Richard; Thorpe, Harry A.; Feil, Edward J.; Blanc, Dominique S.

    2016-01-01

    ABSTRACT Whole-genome sequencing (WGS) of 228 isolates was used to elucidate the origin and dynamics of a long-term outbreak of methicillin-resistant Staphylococcus aureus (MRSA) sequence type 228 (ST228) SCCmec I that involved 1,600 patients in a tertiary care hospital between 2008 and 2012. Combining of the sequence data with detailed metadata on patient admission and movement confirmed that the outbreak was due to the transmission of a single clonal variant of ST228, rather than repeated i...

  8. The Stealthy Superbug: The role of asymptomatic enteric carriage in maintaining a long-term hospital outbreak of ST228 methicillin-resistant Staphylococcus aureus.

    OpenAIRE

    Senn, L; Clerc, O; Zanetti, G; Basset, P.; Prod'hom, G.; Gordon, NC; Sheppard, AE; Crook, DW; JAMES, R; Thorpe, HA; Feil, EJ; Blanc, DS

    2016-01-01

    Whole-genome sequencing (WGS) of 228 isolates was used to elucidate the origin and dynamics of a long-term outbreak of methicillin-resistant Staphylococcus aureus(MRSA) sequence type 228 (ST228) SCCmec I that involved 1,600 patients in a tertiary care hospital between 2008 and 2012. Combining of the sequence data with detailed metadata on patient admission and movement confirmed that the outbreak was due to the transmission of a single clonal variant of ST228, rather than repeated introductio...

  9. A Role of Staphyococcus aureus, Interleukin-18, Nerve Growth Factor and Semaphorin 3A, an Axon Guidance Molecule, in Pathogenesis and Treatment of Atopic Dermatitis

    OpenAIRE

    Ikezawa, Zenro; Komori, Junko; Ikezawa, Yuko; Inoue, Yusuke; Kirino, Mio; Katsuyama, Masako; Aihara, Michiko

    2010-01-01

    Staphylococcus aureus (SA) is usually present not only in the skin lesions of atopic dermatitis (AD) but also in the atopic dry skin. SA discharges various toxins and enzymes that injure the skin, results in activation of epidermal keratinocytes, which produce and release IL-18. IL-18 that induces the super Th1 cells secreting IFN-γ and IL-13 is supposed to be involved in development of AD and its pathogenesis. Indeed, the number of SA colonies on the skin surface and the serum IL-18 levels i...

  10. Signaling mechanism by the Staphylococcus aureus two-component system LytSR: role of acetyl phosphate in bypassing the cell membrane electrical potential sensor LytS

    OpenAIRE

    Kevin Patel; Dasantila Golemi-Kotra

    2016-01-01

    The two-component system LytSR has been linked to the signal transduction of cell membrane electrical potential perturbation and is involved in the adaptation of Staphylococcus aureus to cationic antimicrobial peptides. It consists of a membrane-bound histidine kinase, LytS, which belongs to the family of multiple transmembrane-spanning domains receptors, and a response regulator, LytR, which belongs to the novel family of non-helix-turn-helix DNA-binding domain proteins. LytR regulates the e...

  11. Nosocomial Gram-negative bacteremia in intensive care: epidemiology, antimicrobial susceptibilities, and outcomes

    Directory of Open Access Journals (Sweden)

    Wendy Irene Sligl

    2015-08-01

    Conclusions: ICU-acquired Gram-negative bacteremia is associated with high mortality. Resistance to ciprofloxacin, piperacillin/tazobactam, and carbapenems was common. Coronary artery disease, immune suppression, and inadequate empiric antimicrobial therapy were independently associated with increased mortality.

  12. Bartonella spp. bacteremia in blood donors from Campinas, Brazil.

    Directory of Open Access Journals (Sweden)

    Luiza Helena Urso Pitassi

    2015-01-01

    Full Text Available Bartonella species are blood-borne, re-emerging organisms, capable of causing prolonged infection with diverse disease manifestations, from asymptomatic bacteremia to chronic debilitating disease and death. This pathogen can survive for over a month in stored blood. However, its prevalence among blood donors is unknown, and screening of blood supplies for this pathogen is not routinely performed. We investigated Bartonella spp. prevalence in 500 blood donors from Campinas, Brazil, based on a cross-sectional design. Blood samples were inoculated into an enrichment liquid growth medium and sub-inoculated onto blood agar. Liquid culture samples and Gram-negative isolates were tested using a genus specific ITS PCR with amplicons sequenced for species identification. Bartonella henselae and Bartonella quintana antibodies were assayed by indirect immunofluorescence. B. henselae was isolated from six donors (1.2%. Sixteen donors (3.2% were Bartonella-PCR positive after culture in liquid or on solid media, with 15 donors infected with B. henselae and one donor infected with Bartonella clarridgeiae. Antibodies against B. henselae or B. quintana were found in 16% and 32% of 500 blood donors, respectively. Serology was not associated with infection, with only three of 16 Bartonella-infected subjects seropositive for B. henselae or B. quintana. Bartonella DNA was present in the bloodstream of approximately one out of 30 donors from a major blood bank in South America. Negative serology does not rule out Bartonella spp. infection in healthy subjects. Using a combination of liquid and solid cultures, PCR, and DNA sequencing, this study documents for the first time that Bartonella spp. bacteremia occurs in asymptomatic blood donors. Our findings support further evaluation of Bartonella spp. transmission which can occur through blood transfusions.

  13. Global transcriptome analysis reveals small RNAs affecting Neisseria meningitidis bacteremia.

    Directory of Open Access Journals (Sweden)

    Luca Fagnocchi

    Full Text Available Most bacterial small RNAs (sRNAs are post-transcriptional regulators involved in adaptive responses, controlling gene expression by modulating translation or stability of their target mRNAs often in concert with the RNA chaperone Hfq. Neisseria meningitides, the leading cause of bacterial meningitis, is able to adapt to different host niches during human infection. However, only a few sRNAs and their functions have been fully described to date. Recently, transcriptional expression profiling of N. meningitides in human blood ex vivo revealed 91 differentially expressed putative sRNAs. Here we expanded this analysis by performing a global transcriptome study after exposure of N. meningitides to physiologically relevant stress signals (e.g. heat shock, oxidative stress, iron and carbon source limitation. and we identified putative sRNAs that were differentially expressed in vitro. A set of 98 putative sRNAs was obtained by analyzing transcriptome data and 8 new sRNAs were validated, both by Northern blot and by primer extension techniques. Deletion of selected sRNAs caused attenuation of N. meningitides infection in the in vivo infant rat model, leading to the identification of the first sRNAs influencing meningococcal bacteremia. Further analysis indicated that one of the sRNAs affecting bacteremia responded to carbon source availability through repression by a GntR-like transcriptional regulator. Both the sRNA and the GntR-like regulator are implicated in the control of gene expression from a common network involved in energy metabolism.

  14. Time to positivity in blood cultures of adults with Streptococcus pneumoniae bacteremia

    OpenAIRE

    Ansorena Luis; Garrido Jose; Rodríguez-Lera María; Peralta Galo; Roiz María

    2006-01-01

    Abstract Background previous studies have established that bacterial blood concentration is related with clinical outcome. Time to positivity of blood cultures (TTP) has relationship with bacterial blood concentration and could be related with prognosis. As there is scarce information about the usefulness of TTP, we study the relationship of TTP with clinical parameters in patients with Streptococcus pneumoniae bacteremia. Methods TTP of all cases of Streptococcus pneumoniae bacteremia, detec...

  15. Population-Based Surveillance for Hypermucoviscosity Klebsiella pneumoniae Causing Community-Acquired Bacteremia in Calgary, Alberta

    OpenAIRE

    Gisele Peirano; Johann DD Pitout; Laupland, Kevin B; Bonnie Meatherall; Gregson, Daniel B.

    2013-01-01

    The characteristics of hypermucoviscosity isolates among Klebsiella pneumoniae causing community-acquired bacteremia were investigated. The hypermucoviscous phenotype was present in 8.2% of K pneumoniae isolates, and was associated with rmpA and the K2 serotype; liver abscesses were the most common clinical presentation. The present analysis represents the first population-based surveillance study of hypermucoviscosity among K pneumoniae causing bacteremia.

  16. A quantitative analysis of the interactions of antipneumococcal antibody and complement in experimental pneumococcal bacteremia.

    OpenAIRE

    Brown, E J; Hosea, S W; Hammer, C H; Burch, C G; Frank, M M

    1982-01-01

    The mechanism of protection of type-specific antipneumococcal antibody and complement in bacteremia was investigated with purified rabbit antibody and a guinea pig model of pneumococcal bacteremia. IgG and IgM were isolated from the sera of rabbits immunized with type 7 pneumococci (Pn), and their binding to Pn was quantitated. The number of antibody-binding sites on the pnuemococcal capsule was also determined. Pn were incubated with various amounts of the immunoglobulin preparations before ...

  17. Evaluation of the incidence of occult bacteremia among children with fever of unknown origin

    Directory of Open Access Journals (Sweden)

    Eitan Naaman Berezin

    2006-12-01

    Full Text Available We reviewed the incidence of occult bacteremia, to identify the most frequent etiological agents of bacteremias in otherwise healthy children from one month to 10 years old, who had fever of unknown origin attended at the emergency ward of an urban, university-affiliated pediatric referral center. This was a retrospective medical record review, evaluating children with fever. Data were collected from the initial visit, when blood cultures, hematological properties and hemosedimentation rates were examined. Fever was considered as the highest temperature assessed in the hospital or reported by the responsible adult. Occult bacteremia was discovered in 1.4% of the 1,051 children evaluated, and the most common etiologic agent was Streptococcus pneumoniae. Total leukocyte count and blood sedimentation rates greater than 30 mm³ were not predictive factors for occult bacteremia. Fever greater than 39ºC was the most important factor for predicting occult bacteremia (P<0.001. The presence of occult bacteremia was significantly correlated with patient hospitalization.

  18. Staphylococcus aureus Transcriptome Architecture

    DEFF Research Database (Denmark)

    Mäder, Ulrike; Nicolas, Pierre; Depke, Maren;

    2016-01-01

    Staphylococcus aureus is a major pathogen that colonizes about 20% of the human population. Intriguingly, this Gram-positive bacterium can survive and thrive under a wide range of different conditions, both inside and outside the human body. Here, we investigated the transcriptional adaptation of S....... aureus HG001, a derivative of strain NCTC 8325, across experimental conditions ranging from optimal growth in vitro to intracellular growth in host cells. These data establish an extensive repertoire of transcription units and non-coding RNAs, a classification of 1412 promoters according...... to their dependence on the RNA polymerase sigma factors SigA or SigB, and allow identification of new potential targets for several known transcription factors. In particular, this study revealed a relatively low abundance of antisense RNAs in S. aureus, where they overlap only 6% of the coding genes, and only 19...

  19. Staphylococcus aureus antimicrobial susceptibility of abscess samples from adults and children from the Kaleida Health System in western New York State, 2003 to 2006.

    Science.gov (United States)

    Hsiao, Chiu-Bin; Dryja, Diane; Abbatessa, Laurie; Patel, Pravin H

    2010-05-01

    Staphylococcus aureus is the most common etiologic agent of skin abscesses. The regional rate of methicillin-resistant S. aureus (MRSA) abscesses may reflect the prevalence of local community-acquired MRSA (CAMRSA). A retrospective study was conducted to compare the antimicrobial susceptibility patterns of S. aureus isolates recovered from abscesses from 2003 to 2006 from patients at hospitals of the Kaleida Health System in western New York. S. aureus susceptibility information was obtained from a Vitek Legacy system, and the location and source of each isolate were identified. EpiInfo software was used to analyze the antimicrobial susceptibilities of all isolates and the trends in the rates of MRSA. A total of 2,848 S. aureus abscesses were identified by the Kaleida Health Clinical Microbiology Laboratory. Of those, 978 S. aureus abscess events occurred in four hospitals, including three adult facilities (547 episodes with 62 cases of bacteremia) and one children's facility (431 episodes with 2 cases of bacteremia). The MRSA rates in adults increased from 56% (2003) to 71% (2006), and that in children increased from 26% (2003) to 64% (2006). Of the MRSA isolates in the children's samples, more than 92% were susceptible to clindamycin. Of the MRSA isolates in the adult samples, 50% were susceptible to clindamycin in 2003 and 2004, whereas greater than 75% were susceptible in 2005 and 2006. The increased rates of MRSA abscesses with susceptibility to clindamycin may reflect the high prevalence level of CAMRSA in the western New York community. The variations in S. aureus susceptibilities could serve as an indicator of the changing resistance patterns within a broad urban community. PMID:20181909

  20. Risk factors for pan-resistant Pseudomonas aeruginosa bacteremia and the adequacy of antibiotic therapy

    Directory of Open Access Journals (Sweden)

    Felipe F. Tuon

    2012-08-01

    Full Text Available INTRODUCTION: The aim of this study was to determine risk factors for acquiring carbapenemresistant Pseudomonas aeruginosa bacteremia (CR-PA and factors associated with in-hospital mortality. METHODS: Seventy-seven cases of bacteremia caused by P. aeruginosa were evaluated in a hospital with high incidence of CR-PA. Clinical and laboratorial factors, and previous use of antibiotics were also evaluated. In one analysis, CR-PA and carbapenem-susceptible P. aeruginosa (CS-PA bacteremia were compared. A second analysis compared patients who died with survivors. RESULTS: Among 77 P. aeruginosa bacteremia, 29 were caused by CR-PA. Admission to the intensive care unit, higher number of total leukocytes, and previous use of carbapenem were statistically associated with CR-PA. In the multivariate analysis, only previous use of carbapenem (including ertapenem turned out to be a risk factor for CR-PA (p = 0.014. The 30-day mortality of patients with P. aeruginosa bloodstream infection was 44.8% for CS-PA and 54.2% for patients with CR-PA (p = 0.288. Chronic renal failure, admission to the intensive care unit, mechanical ventilation, and central venous catheter were risk factors for mortality. Incorrect treatment increased mortality of patients with bacteremia caused by CS-PA, but not for CR-SA. The odd ratio of mortality associated with incorrect therapy in patients with CS-PA was 3.30 (1.01-10.82; p = 0.043. The mortality of patients with bacteremia caused by CR-PA was unexpectedly similar regardless of antimicrobial treatment adequacy. CONCLUSION: Appropriate treatment for CS-PA bacteremia initiated within the first 24 hours was associated with lower mortality, but this cannot be extrapolated for CR-PA.

  1. A case-control study of mastitis: nasal carriage of Staphylococcus aureus

    OpenAIRE

    Garland Suzanne M; Amir Lisa H; Lumley Judith

    2006-01-01

    Abstract Background Mastitis is a common problem for breastfeeding women. Researchers have called for an investigation into the possible role of maternal nasal carriage of S. aureus in the causation of mastitis in breastfeeding women. Methods The aim of the study was to investigate the role of maternal S. aureus nasal carriage in mastitis. Other factors such as infant nasal S. aureus carriage, nipple damage, maternal fatigue and oversupply of milk were also investigated. A case-control design...

  2. Implantation of Corynebacterium pseudodiphtheriticum for elimination of Staphylococcus aureus from the nasal cavity in volunteers

    Science.gov (United States)

    Viacheslav, Ilyin; Kiryukhina, Nataliya

    Nasal carriage of Staphylococcus aureus is a well-documented risk factor of infection and inflammation of the skin, soft tissues and bacteremia. It is also known that most often etiology of these disorders is associated with autoinfection. The present-day methods of opportunistic pathogens eradication from the nasal cavity are based principally on the use of antiseptic and antibacterial agents. For instance, a local antibiotic mupirocin in the form of nasal ointment is considered to be the gold standard for the treatment of S. aureus carriage. The literature describes investigations showing how mupirocin can strengthen antibiotic resistance in S. aureus strains, including those with methicillin resistance (MRSA). It is also common knowledge that recolonization of the nasal mucous membrane takes place within several months after mupirocin treatment. This circumstance dictates the necessity to look for alternative ways of preventing the S. aureus carriage and methods of elimination. One of the methods of nasal S. aureus elimination is implantation of nonpathogenic microorganisms which will extrude opportunistic pathogens without impinging the symbiotic microbiota. Effectiveness of saline suspension of Corynebacterium pseudodiphtheriticum containing spray was assessed in a several chamber experiments with simulation of some spaceflight factors (dry immersion, isolation). Various schemes of application of preparations were applied. In all cases of corynebacteria application the strong inhibiting effect against S. aureus was detected. This fact opens a prospect of using nonpathogenic corynebacteria as a nasal probiotic. Administration of the nasal corynebacteria spray possibly prevented cross-infection by MRSA and appearance of staphylococcal infection. Further pre-clinical and clinical study of this bacterial therapy method is under development.

  3. [A Case of Bacteremia Caused by Ochrobacterium intermedium].

    Science.gov (United States)

    Hirai, Jun; Yamagishi, Yuka; Sakanashi, Daisuke; Koizumi, Yusuke; Suematsu, Hiroyuki; Mikamo, Hiroshige

    2016-03-01

    We report herein on a case of bacteremia caused by Ochrobactrum intermedium (O. intermedium) identified with biotyper matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). An 86-year-old man was admitted to our hospital with paralysis of the right side of the body and dysphagia. He was diagnosed as having a pontine infarction based on the brain MRI findings and was admitted to hospital to have anti-platelet therapy. Three days after admission, he had a fever. Although he had redness and swelling at the peripheral venous catheter insertion site, he was diagnosed as having aspiration pneumonia, since he had fine crackles on auscultation. Soon after taking two sets of blood cultures and removal of the peripheral venous catheter, sulbactam/ampicillin (SBT/ABPC) was administrated. Fifty three hours after incubation, gram-negative bacilli was detected from an aerobic bottle and identified as O. intermedium with MALDI-TOF MS (Bruker MS). Antimicrobial chemotherapy was changed to meropenem (MEPM). He was treated for a total of seven days, and recovered without relapse. Infection caused by O. intermedium has been very uncommon, however, O. intermedium has been recognized as an emerging pathogen in immunodeficient and immunocompetent patients. Since identification of Ochrobactrum species by biochemical methods could be difficult, MALDI-TOF MS might be helpful to clarify Ochrobactrum species just as in the present case. PMID:27197440

  4. Shigella Bacteremia in a Patient with Visceral Leishmaniasis

    Directory of Open Access Journals (Sweden)

    Mengistu Endris

    2013-01-01

    Full Text Available Bacteremia due to Shigella is rare. A 26-year-old HIV-negative male presented with a persistent high-grade fever of two months duration to the Leishmaniasis Research and Treatment Center of University of Gondar Hospital. He was anorexic and had lost significant weight (from 76 to 57 kg in 4 months, BMI = 17.2 kg/m2. He also complained of headache, chills, and rigor. In the last one year, he was experiencing a few episodes of acute bloody diarrhea, the last episode being two months ago. Microscopy from splenic aspiration showed Leishman-Donovan bodies with parasite load of +3. The blood culture showed Shigella species, but the stool was culture negative. The isolate was sensitive to most tested antibiotic discs, sulfamethoxazole, ceftriaxone, gentamicin, tetracycline, and norfloxacilin, except ampicillin. Therefore, requesting blood culture for identifying unexpected type of organisms causing infections in patients with underlying diseases like visceral leishmaniasis should be encouraged.

  5. Appropriate empirical antibiotic use and 30-d mortality in cirrhotic patients with bacteremia

    Science.gov (United States)

    Park, Hyun; Jang, Ki Jun; Jang, Won; Park, Sang Hoon; Park, Ji Young; Jeon, Tae Joo; Oh, Tae Hoon; Shin, Won Chang; Choi, Won-Choong; Sinn, Dong Hyun

    2015-01-01

    AIM: To analyze whether prompt and appropriate empirical antibiotic (AEA) use is associated with mortality in cirrhotic patients with bacteremia. METHODS: A total of 102 episodes of bacteremia in 72 patients with cirrhosis were analyzed. AEA was defined as a using or starting an antibiotic appropriate to the isolated pathogen at the time of bacteremia. The primary endpoint was 30-d mortality. RESULTS: The mortality rate at 30 d was 30.4% (31/102 episodes). Use of AEA was associated with better survival at 30 d (76.5% vs 46.9%, P = 0.05), and inappropriate empirical antibiotic (IEA) use was an independent factor associated with increased mortality (OR = 3.24; 95%CI: 1.50-7.00; P = 0.003, adjusted for age, sex, Child-Pugh Class, gastrointestinal bleeding, presence of septic shock). IEA use was more frequent when the isolated pathogen was a multiresistant pathogen, and when infection was healthcare-related or hospital-acquired. CONCLUSION: AEA use was associated with increased survival of cirrhotic patients who developed bacteremia. Strategies for AEA use, tailored according to the local epidemiological patterns, are needed to improve survival of cirrhotic patients with bacteremia. PMID:25834324

  6. Recent changes in bacteremia in patients with cancer: a systematic review of epidemiology and antibiotic resistance.

    Science.gov (United States)

    Montassier, E; Batard, E; Gastinne, T; Potel, G; de La Cochetière, M F

    2013-07-01

    Bacteremia remains a major cause of life-threatening complication in patients with cancer. Significant changes in the spectrum of microorganisms isolated from blood culture have been reported in cancer patients over the past years. The aim of our systematic review was to inventory the recent trends in epidemiology and antibiotic resistance of microorganisms causing bacteremia in cancer patients. Data for this review was identified by searches of Medline, Scopus and Cochrane Library for indexed articles and abstracts published in English since 2008. The principal search terms were: "antimicrobial resistance", "bacteremia", "bacterial epidemiology", "bloodstream infection", "cancer patients", "carbapenem resistance", "Escherichia coli resistance", "extended-spectrum β-lactamase producing E. coli", "febrile neutropenia", "fluoroquinolone resistance", "neutropenic cancer patient", "vancomycin-resistant Enterococcus", and "multidrug resistance". Boolean operators (NOT, AND, OR) were also used in succession to narrow and widen the search. Altogether, 27 articles were selected to be analyzed in the review. We found that Gram-negative bacteria were the most frequent pathogen isolated, particularly in studies with minimal use of antibiotic prophylaxis. Another important trend is the extensive emergence of antimicrobial-resistant strains associated with increased risk of morbidity, mortality and cost. This increasing incidence of antibiotic resistance has been reported in Gram-negative bacteria as well as in Gram-positive bacteria. This exhaustive review, reporting the recent findings in epidemiology and antibiotic resistance of bacteremia in cancer patients, highlights the necessity of local continuous surveillance of bacteremia and stringent enforcement of antibiotic stewardship programs in cancer patients. PMID:23354675

  7. Chorioamnionitis caused by Staphylococcus aureus with intact membranes in a term pregnancy: A case of maternal and fetal septic shock.

    Science.gov (United States)

    Sorano, Sumire; Goto, Maki; Matsuoka, Sakiko; Tohyama, Atsushi; Yamamoto, Hiroko; Nakamura, Sumie; Fukami, Tatsuya; Matsuoka, Ryoei; Tsujioka, Hiroshi; Eguchi, Fuyuki

    2016-04-01

    Chorioamnionitis is usually caused by migration of cervicovaginal flora through the cervical canal in women with ruptured membranes. Common causative pathogens are genital mycoplasmas, anaerobes, enteric gram-negative bacilli, and group B streptococcus. There have been only seven previous reports of chorioamnionitis due to Staphylococcus aureus and their clinical courses are characterized by rapid disease progression and poor prognosis. This case report describes a case of acute chorioamnionitis due to S. aureus, which was successfully managed with immediate cesarean section and postoperative intensive care. A 22-year-old woman presented at 39 weeks' gestation with a fever and acute lower abdominal pain. Fetal heart monitoring showed fetal distress. Immediate cesarean delivery was performed under general anesthesia. A male infant weighing 2450 g was born. He had Apgar scores of 3 and 7 at 1 and 5 min, respectively. He was immediately intubated and admitted to the neonatal intensive care unit. Maternal blood culture, vaginal culture, neonatal nares, and blood and gastric fluid culture all showed methicillin-sensitive S. aureus. Histopathology of the placenta demonstrated focal acute funisitis and acute chorioamnionitis. Interestingly, most of the patients in the previous reports developed chorioamnionitis due to S. aureus despite the presence of intact membranes, as in our case. Bacterial spread in the absence of membrane rupture and the presence of bacteremia suggests hematogenous, rather than ascending, etiology of S. aureus chorioamnionitis. PMID:26705749

  8. Inhibiting platelets aggregation could aggravate the acute infection caused by Staphylococcus aureus.

    Science.gov (United States)

    Zhang, Xin; Liu, Yu; Gao, Yaping; Dong, Jie; Mu, Chunhua; Lu, Qiang; Shao, Ningsheng; Yang, Guang

    2011-01-01

    Several fibrinogen binding proteins (Fibs) play important roles in the pathogenesis of Staphylococcus aureus (S. aureus). Most Fibs can promote the aggregation of platelets during infection, but the extracellular fibrinogen-binding protein (Efb) is an exception. It is reported that Efb can specifically bind fibrinogen and inhibit the aggregation of platelet with its N terminal. However, the biological significance of platelet aggregation inhibition in the infection caused by S. aureus is unclear until now. Here, we demonstrated that the persistence and aggregation of platelets were important for killing S. aureus in whole blood. It was found that the N terminal of Efb (EfbN) and platelets inhibitors could increase the survival of S. aureus in whole blood. The study in vivo also showed that EfbN and platelets inhibitors could reduce the killing of S. aureus and increase the lethality rate of S. aureus in the acute infection mouse model.

  9. Ductus arteriosus aneurysm with community-acquired methicillin-resistant Staphylococcus aureus infection and spontaneous rupture: a potentially fatal quandary.

    Science.gov (United States)

    Stewart, Audra; Dyamenahalli, Umesh; Greenberg, S Bruce; Drummond-Webb, Jonathan

    2006-06-01

    We present the case of a 6-month-old previously healthy girl who presented with high fever, labored breathing, and an enlarged cardiac silhouette on her chest radiograph. Comprehensive evaluation discovered a ductus arteriosus aneurysm and pericardial effusion with methicillin-resistant Staphylococcus aureus bacteremia. Despite pericardiocentesis and appropriate intravenous antibiotics, there was rapid enlargement of the aneurysm and accumulation of echogenic material within the ductus arteriosus aneurysm. Infected aneurysm rupture was identified during emergency surgery. This infant also had vocal cord paresis, a likely complication of the surgery. The clinical course, diagnosis, and treatment of this patient are discussed. Infection of a ductus arteriosus or an infected ductal arteriosus aneurysm is a rare and potentially fatal clinical entity. In the era of increasing community-acquired methicillin-resistant S aureus infections, this is a diagnosis that requires a high index of suspicion.

  10. Effect of socioeconomic status on mortality after bacteremia in working-age patients. A danish population-based cohort study

    DEFF Research Database (Denmark)

    Koch, Kristoffer; Nørgaard, Mette; Schønheyder, Henrik Carl;

    2013-01-01

    To examine the effect of socioeconomic status (SES) on mortality in patients with bacteremia and the underlying factors that may mediate differences in mortality.......To examine the effect of socioeconomic status (SES) on mortality in patients with bacteremia and the underlying factors that may mediate differences in mortality....

  11. Bacteremia in a Long-Term -Care Facility: a Five-Year Prospective Study of 163 Consecutive Episodes

    NARCIS (Netherlands)

    R.R. Muder; C. Brennen; M.M. Wagener (Marilyn); A.M. Geotz

    1992-01-01

    textabstractThe clinical features, microbiological characteristics, and outcomes of 163 episodes of bacteremia occurring at a long-term-care facility were evaluated. The rate of nosocomial bacteremia increased from 0.20 to 0.36 cases/1,000 patient-days from 1985 to 1989; there was a parallel increas

  12. Increase in hippocampal water diffusion and volume during experimental pneumococcal meningitis is aggravated by bacteremia

    DEFF Research Database (Denmark)

    Holler, Jon G; Brandt, Christian T; Leib, Stephen L;

    2014-01-01

    BACKGROUND: The hippocampus undergoes apoptosis in experimental pneumococcal meningitis leading to neurofunctional deficits in learning and memory function. The aim of the present study was 1) to investigate hippocampal apparent diffusion coefficient (ADC) and volume with MRI during the course...... of experimental pneumococcal meningitis, 2) to explore the influence of accompanying bacteremia on hippocampal water distribution and volume, 3) and to correlate these findings to the extent of apoptosis in the hippocampus. METHODS: Experimental meningitis in rats was induced by intracisternal injection of live...... pneumococci. The study comprised of four experimental groups. I. Uninfected controls (n = 8); II. Meningitis (n = 11); III. Meningitis with early onset bacteremia by additional i.v. injection of live pneumococci (n = 10); IV. Meningitis with attenuated bacteremia by treatment with serotype-specific anti...

  13. Signaling mechanism by the Staphylococcus aureus two-component system LytSR: role of acetyl phosphate in bypassing the cell membrane electrical potential sensor LytS.

    Science.gov (United States)

    Patel, Kevin; Golemi-Kotra, Dasantila

    2015-01-01

    The two-component system LytSR has been linked to the signal transduction of cell membrane electrical potential perturbation and is involved in the adaptation of Staphylococcus aureus to cationic antimicrobial peptides. It consists of a membrane-bound histidine kinase, LytS, which belongs to the family of multiple transmembrane-spanning domains receptors, and a response regulator, LytR, which belongs to the novel family of non-helix-turn-helix DNA-binding domain proteins. LytR regulates the expression of cidABC and lrgAB operons, the gene products of which are involved in programmed cell death and lysis. In vivo studies have demonstrated involvement of two overlapping regulatory networks in regulating the lrgAB operon, both depending on LytR. One regulatory network responds to glucose metabolism and the other responds to changes in the cell membrane potential. Herein, we show that LytS has autokinase activity and can catalyze a fast phosphotransfer reaction, with 50% of its phosphoryl group lost within 1 minute of incubation with LytR. LytS has also phosphatase activity. Notably, LytR undergoes phosphorylation by acetyl phosphate at a rate that is 2-fold faster than the phosphorylation by LytS. This observation is significant in lieu of the in vivo observations that regulation of the lrgAB operon is LytR-dependent in the presence of excess glucose in the medium. The latter condition does not lead to perturbation of the cell membrane potential but rather to the accumulation of acetate in the cell. Our study provides insights into the molecular basis for regulation of lrgAB in a LytR-dependent manner under conditions that do not involve sensing by LytS. PMID:27127614

  14. Clinical manifestations of bacteremia caused by Aeromonas species in southern Taiwan.

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    Hung-Jen Tang

    Full Text Available This study is conducted to investigate the clinical characteristics of patients with bacteremia caused by Aeromonas species.Patients with bacteremia caused by Aeromonas species during the period 2009 to 2013 were identified from a computerized database of a regional hospital in southern Taiwan. The medical records of these patients were retrospectively reviewed.A total of 91 patients with bacteremia due to Aeromonas species were identified. In addition to 16 (17.6% primary bacteremia, the most common source of secondary infection is peritonitis (n = 27, 29.7%, followed by biliary tract infection (n = 18, 19.8%, and SSTI (n = 12, 13.2%, pneumonia (n = 9, 9.9%, catheter-related bloodstream infection (n =  5, 5.5%, and genitourinary tract infection (n = 4, 4.4%. A. hydrophila (n = 35, 38.5% was the most common pathogen, followed by A. veronii biovar sobria (n = 31, 34.1%, A. caviae (n = 14, 15.4%, and A. veronii biovar veronii (n = 9, 9.9%. Forty-three (47.3% patients were classified as healthcare-associated infections (HCAI causes by Aeromonas species, and patients with HCAI were more likely to have cancer, and receive immunosuppressant than patients with community-acquired bacteremia. The overall outcomes, including rate of ICU admission, acute respiratory failure, and mortality were 33.3%, 28.6%, and 23.1%, respectively. Multivariate analysis showed that the in-hospital day mortality was significantly associated only with underlying cancer (P <.001, and initial shock (P <.001.Aeromonas species should be considered one of the causative pathogens of healthcare-associated bacteremia, especially in immunocompromised patients. In addition, it can be associated with high fatality. Cancer and initial shock were the poor prognostic factors.

  15. Postoperative bacteremia in periodontal flap surgery, with and without prophylactic antibiotic administration: A comparative study

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    Asi Kanwarjit

    2010-01-01

    Full Text Available Objectives: Many a times in clinical periodontology, the decision whether to prescribe prophylactic antibiotics or not , is perplexing.The present study was conducted to compare the bacteremias induced after periodontal flap surgeries with and without prophylactic antibiotics. Materials and Methods: The occurrence of postoperative bacteremia following periodontal flap surgery was studied in 30 patients. On these patients, 30 quadrant wise flap surgeries were carried out without any preoperative prophylactic antibiotics and 30 surgeries carried out after prophylactic administration of amoxycillin preoperatively. A blood sample was taken from each patient at the time of maximum surgical trauma and was cultured for micro-organisms and antibiotic sensitivity. Results: 18 out of 60 blood samples were positive for micro-organisms. There was a significant reduction in post operative bacteremia after amoxycillin prophylaxis (x - 7.96 with P< 0.01 as post operative bacteremia was found in 14 of the non medicated patients as compared to only 4 of the pre medicated patients. The micro-organisms encountered in the study are as follows:- 1 Staphylococcus albus coagulase negative, 2 Klebsiella, 3 Psedomonas aerugenosa, 4 Streptococcus viridans, 5 Alpha hemolytic streptococcus, 6 Neisseria catarrhalis Conclusion: On the basis of the study, it is concluded that the incidence of postoperative bacteremia following periodontal flap surgery is not as high as previously reported. The clinical results show that Amoxicillin is highly effective in reducing postoperative bacteremia in periodontal flap surgery and thus in preventing the possible sequelae (Infective Endocarditis and other systemic maladies in susceptible patients. However, cefotaxime and cephalexin may prove to be more effective in preventing the same.

  16. Successful Treatment of Bacillus cereus Bacteremia in a Patient with Propionic Acidemia

    Science.gov (United States)

    Aygun, Fatih; Cam, Halit

    2016-01-01

    Bacillus cereus can cause serious, life-threatening, systemic infections in immunocompromised patients. The ability of microorganism to form biofilm on biomedical devices can be responsible for catheter-related bloodstream infections. Other manifestations of severe disease are meningitis, endocarditis, osteomyelitis, and surgical and traumatic wound infections. The most common feature in true bacteremia caused by Bacillus is the presence of an intravascular catheter. Herein, we report a case of catheter-related bacteremia caused by B. cereus in a patient with propionic acidemia. PMID:27195164

  17. Successful Treatment of Bacillus cereus Bacteremia in a Patient with Propionic Acidemia.

    Science.gov (United States)

    Aygun, Fatma Deniz; Aygun, Fatih; Cam, Halit

    2016-01-01

    Bacillus cereus can cause serious, life-threatening, systemic infections in immunocompromised patients. The ability of microorganism to form biofilm on biomedical devices can be responsible for catheter-related bloodstream infections. Other manifestations of severe disease are meningitis, endocarditis, osteomyelitis, and surgical and traumatic wound infections. The most common feature in true bacteremia caused by Bacillus is the presence of an intravascular catheter. Herein, we report a case of catheter-related bacteremia caused by B. cereus in a patient with propionic acidemia. PMID:27195164

  18. Successful Treatment of Bacillus cereus Bacteremia in a Patient with Propionic Acidemia

    Directory of Open Access Journals (Sweden)

    Fatma Deniz Aygun

    2016-01-01

    Full Text Available Bacillus cereus can cause serious, life-threatening, systemic infections in immunocompromised patients. The ability of microorganism to form biofilm on biomedical devices can be responsible for catheter-related bloodstream infections. Other manifestations of severe disease are meningitis, endocarditis, osteomyelitis, and surgical and traumatic wound infections. The most common feature in true bacteremia caused by Bacillus is the presence of an intravascular catheter. Herein, we report a case of catheter-related bacteremia caused by B. cereus in a patient with propionic acidemia.

  19. A case of disseminated intravascular coagulation secondary to Acinetobacter lwoffii and Acinetobacter baumannii bacteremia

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    Candice Baldeo

    2015-01-01

    Full Text Available Bacteremia is currently one of the infections with the highest mortality in hospitals [1]. Acinetobacter lwoffii and Acinetobacter baumannii are gram-negative bacteria and both represent opportunistic pathogens. In certain cases, the management can be challenging since these organisms can be highly resistant to antimicrobial agents. Clinical illnesses associated with Acinetobacter include pneumonia, meningitis, peritonitis, endocarditis and infections of the urinary tract and skin [1]. Acinetobacter bacteremia represents a serious and ever increasing problem because of the high associated morbidity and mortality.

  20. Sepsis associated with Lactobacillus bacteremia in a patient with ischemic colitis

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    Hrishikesh S Kulkarni

    2014-01-01

    Full Text Available Lactobacillus species is a known commensal of the mouth, gastrointestinal, and genitourinary tract. However, its isolation on blood cultures is often overlooked and attributed to bench contamination. We present a case of a 58-year-old immunocompetent male who initially presented with altered mental status, but developed sepsis from Lactobacillus bacteremia during his hospital course, while on mechanical ventilation. He was found to have ischemic colitis on colonoscopy. His condition improved with antibiotics and supportive management. Using this example of ischemic colitis, we stress that in the right clinical setting, Lactobacillus bacteremia is a harbinger for a serious underlying pathology and should not be ignored.

  1. Macrophage serum markers in pneumococcal bacteremia: Prediction of survival by soluble CD163

    DEFF Research Database (Denmark)

    Møller, Holger Jon; K. Moestrup, Søren; Wejse, Christian;

    2006-01-01

    with pneumococcal bacteremia. DESIGN: Observational cohort study. SETTING: Five university hospitals in Denmark. PATIENTS: A total of 133 patients with Streptococcus pneumoniae bacteremia (positive blood culture) and 133 age- and gender-matched controls. INTERVENTIONS: Samples were collected for biochemical...... were observed in patients who needed intensive care (hemodialysis, p = .0011; hypotension, p = .0014; mechanical ventilation, p = .0019). Significantly lower levels of sCD163, ferritin, transcobalamin, and suPAR (but not C-reactive protein) were measured in patients > or =75 yrs. In patients

  2. An affinity adsorption media that mimics heparan sulfate proteoglycans for the treatment of drug-resistant bacteremia

    Science.gov (United States)

    McCrea, Keith R.; Ward, Robert S.

    2016-06-01

    Removal of several drug-resistant bacteria from blood by affinity adsorption onto a heparin-functional media is reported. Heparin is a chemical analogue of heparan sulfate (HS) proteoglycans, found on transmembrane proteins of endothelial cells. Many blood-borne human pathogens, including bacteria, viruses, parasites, and fungi have been reported to target HS as an initial step in their pathogenesis. Here, we demonstrate the binding and removal of Methicillin-resistant Staphylococcus aureus (MRSA), Extended-Spectrum Betalactamase Klebsiella pneumoniae (ESBL), and two Carbapenem-resistant Enterobacteriaceae (both CRE Escherichia coli and CRE K. pneumoniae) using 300 μm polyethylene beads surface modified with end-point-attached heparin. Depending on the specific bacteria, the amount removed ranged between 39% (ESBL) and 99.9% (CRE). The total amount of bacteria adsorbed ranged between 2.8 × 105 and 8.6 × 105 colony forming units (CFU) per gram of adsorption media. Based on a polymicrobial challenge which showed no competitive binding, MRSA and CRE apparently utilize different binding sequences on the immobilized heparin ligand. Since the total circulating bacterial load during bacteremia seldom exceeds 5 × 105 CFUs, it appears possible to significantly reduce bacterial concentration in infected patients by multi-pass recirculation of their blood through a small extracorporeal affinity filter containing the heparin-functional adsorption media. This 'dialysis-like therapy' is expected to improve patient outcomes and reduce the cost of care, particularly when there are no anti-infective drugs available to treat the infection.

  3. Epidemiology, microbiology and mortality associated with community-acquired bacteremia in northeast Thailand: a multicenter surveillance study.

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    Manas Kanoksil

    Full Text Available BACKGROUND: National statistics in developing countries are likely to underestimate deaths due to bacterial infections. Here, we calculated mortality associated with community-acquired bacteremia (CAB in a developing country using routinely available databases. METHODS/PRINCIPAL FINDINGS: Information was obtained from the microbiology and hospital database of 10 provincial hospitals in northeast Thailand, and compared with the national death registry from the Ministry of Interior, Thailand for the period between 2004 and 2010. CAB was defined in patients who had pathogenic organisms isolated from blood taken within 2 days of hospital admission without a prior inpatient episode in the preceding 30 days. A total of 15,251 CAB patients identified, of which 5,722 (37.5% died within 30 days of admission. The incidence rate of CAB between 2004 and 2010 increased from 16.7 to 38.1 per 100,000 people per year, and the mortality rate associated with CAB increased from 6.9 to 13.7 per 100,000 people per year. In 2010, the mortality rate associated with CAB was lower than that from respiratory tract infection, but higher than HIV disease or tuberculosis. The most common causes of CAB were Escherichia coli (23.1%, Burkholderia pseudomallei (19.3%, and Staphylococcus aureus (8.2%. There was an increase in the proportion of Extended-Spectrum Beta-Lactamases (ESBL producing E. coli and Klebsiella pneumoniae over time. CONCLUSIONS: This study has demonstrated that national statistics on causes of death in developing countries could be improved by integrating information from readily available databases. CAB is neglected as an important cause of death, and specific prevention and intervention is urgently required to reduce its incidence and mortality.

  4. Dispersal of Bap-mediated Staphylococcus aureus biofilm by proteinase K.

    Science.gov (United States)

    Kumar Shukla, Sudhir; Rao, Toleti Subba

    2013-02-01

    The dominant role of biofilm-associated protein (Bap) in Staphylococcus aureus biofilm development prompted us to investigate Bap as a potential target for proteinase-mediated biofilm dispersion. Biofilm assay in microtitre plates showed that proteinase K hampered the early adhesion of cells as well as biofilm development. Proteinase K treatment of 24- and 48-h-old biofilms showed enhanced dispersion of bap-positive S. aureus biofilm; however, proteinase K did not affect the bap-negative S. aureus biofilm. When antibiotics were used in combination with proteinase K, significant enhancement in antibiotic action was noticed against bap-positive S. aureus biofilm. This study establishes that antibiotics in combination with proteinase K can be used for controlling S. aureus biofilms in whose development Bap surface protein has a major role. We propose that Bap protein could be a potential target for therapeutic control of S. aureus infections (for example, bovine mastitis).

  5. Resistance to Antimicrobials Mediated by Efflux Pumps in Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Isabel Couto

    2013-03-01

    Full Text Available Resistance mediated by efflux has been recognized in Staphylococcus aureus in the last few decades, although its clinical relevance has only been recognized recently. The existence of only a few studies on the individual and overall contribution of efflux to resistance phenotypes associated with the need of well-established methods to assess efflux activity in clinical isolates contributes greatly to the lack of solid knowledge of this mechanism in S. aureus. This study aims to provide information on approaches useful to the assessment and characterization of efflux activity, as well as contributing to our understanding of the role of efflux to phenotypes of antibiotic resistance and biocide tolerance in S. aureus clinical isolates. The results described show that efflux is an important contributor to fluoroquinolone resistance in S. aureus and suggest it as a major mechanism in the early stages of resistance development. We also show that efflux plays an important role on the reduced susceptibility to biocides in S. aureus, strengthening the importance of this long neglected resistance mechanism to the persistence and proliferation of antibiotic/biocide-resistant S. aureus in the hospital environment.

  6. Infertility as a Consequence of Spermagglutinating Staphylococcus aureus Colonization in Genital Tract of Female Mice

    OpenAIRE

    Siftjit Kaur; Vijay Prabha

    2012-01-01

    Various studies have shown Staphylococcus aureus to be one of the most prevalent organism in male and female genital tract but most practitioners dismiss it as mere contamination which is assumed to be of no significance. However, it is now suggested that the presence of this organism should not be ignored, as incubation of spermatozoa with S. aureus results in reduced sperm motility. Although S. aureus has been reported to cause immobilization of spermatozoa, however, its role in infertility...

  7. Ceftaroline Fosamil Use in 2 Pediatric Patients With Invasive Methicillin-Resistant Staphylococcus aureus Infections.

    Science.gov (United States)

    Williams, Amanda W; Newman, Patrick M; Ocheltree, Sara; Beaty, Rachel; Hassoun, Ali

    2015-01-01

    Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is one of the most common pathogens causing pediatric infections including skin and soft tissue infections, pyogenic arthritis, osteomyelitis, and septic shock. For decades, patients were treated with antibiotics such as vancomycin and clindamycin, but there is an increasing incidence of resistance to these traditional therapies. We describe 2 cases of patients with CA-MRSA invasive infections with bacteremia who experienced vancomycin therapy failure but who were successfully treated with ceftaroline fosamil. Case 1 involves an 8-year-old Hispanic male who was diagnosed with CA-MRSA bacteremia, thigh abscess, and osteomyelitis. The patient was admitted to the pediatric intensive care unit in septic shock. Case 2 involves an 8-year-old Caucasian male who was diagnosed with CA-MRSA sepsis, right arm abscess, and osteomyelitis. We were able to successfully treat both patients with CA-MRSA sepsis and invasive infection-who failed vancomycin therapy-with ceftaroline fosamil with no adverse efiects. Despite the positive outcome in both pediatric patients, clinical trials with ceftaroline fosamil are needed to further support its use in pediatric patients. PMID:26766937

  8. Central venous catheter-related bloodstream infection caused by Staphylococcus aureus: microbiology and risk factors

    Directory of Open Access Journals (Sweden)

    Geraldo Sadoyma

    2006-04-01

    Full Text Available Although central vascular catheters (CVC are indispensable in modern medicine, they are an important risk factor for primary bacteremias. We examined the incidence and risk factors associated with catheter-related bloodstream infection (CR-BSI caused by Staphylococcus aureus in surgical patients. A prospective study was carried out in the Hospital das Clínicas da Universidade Federal de Uberlândia (HC-UFU from September 2000 to December 2002. The skin insertion site, catheter tip, and blood were microbiologically analyzed. Demographics and risk factors were recorded for each patient, and cultures were identified phenotypically. Staphylococcus aureus was the most frequent pathogen, with an incidence rate of 4.9 episodes of CR-BSIs per 1,000 catheter/days. Based on logistic regression, the independent risk factors were: colonization on the insertion site =200 colony forming units (CFU/20 cm² (p=0.03; odds ratio (OR =6.89 and catheter tip (p=0.01; OR=7.95. The CR-BSI rate was high; it was mainly associated with S. aureus, and skin colonization at the insertion site and on the catheter tip were important risk factors for CR-BSI.

  9. Methicillin-resistant Staphylococcus aureus: the superbug.

    Science.gov (United States)

    Ippolito, Giuseppe; Leone, Sebastiano; Lauria, Francesco N; Nicastri, Emanuele; Wenzel, Richard P

    2010-10-01

    Over the last decade, methicillin-resistant Staphylococcus aureus (MRSA) strains have emerged as serious pathogens in the nosocomial and community setting. Hospitalization costs associated with MRSA infections are substantially greater than those associated with methicillin-sensitive S. aureus (MSSA) infections, and MRSA has wider economic effects that involve indirect costs to the patient and to society. In addition, there is some evidence suggesting that MRSA infections increase morbidity and the risk of mortality. Glycopeptides are the backbone antibiotics for the treatment of MRSA infections. However, several recent reports have highlighted the limitations of vancomycin, and its role in the management of serious infections is now being reconsidered. Several new antimicrobials demonstrate in vitro activity against MRSA and other Gram-positive bacteria. Data from large surveys indicate that linezolid, daptomycin, and tigecycline are almost universally active against MRSA. This review will briefly discuss the epidemiology, costs, outcome, and therapeutic options for the management of MRSA infections. PMID:20851011

  10. Salmonella enterica Serovar Virchow Bacteremia Presenting as Typhoid-Like Illness in an Immunocompetent Patient ▿

    OpenAIRE

    Eckerle, Isabella; Zimmermann, Stefan; Kapaun, Annette; Junghanss, Thomas

    2010-01-01

    We report a typhoid-like illness with fever and altered consciousness in a 22-year-old man with growth of Salmonella enterica serovar Virchow in blood and stool culture. Bacteremia and invasive disease due to non-typhoid salmonellae (NTS) are known in severely immunocompromised patients, but so far have not been described in immunocompetent adults.

  11. Catheter-related Rahnella aquatilis bacteremia in a pediatric bone marrow transplant recipient.

    OpenAIRE

    Hoppe, J E; Herter, M.; Aleksic, S; Klingebiel, T; Niethammer, D

    1993-01-01

    Rahnella aquatilis, a rarely encountered member of the family Enterobacteriaceae, was twice isolated from the blood of a pediatric bone marrow transplant recipient. This is the first report of a pediatric case of R. aquatilis bacteremia, and it was probably related to inappropriate handling of a Hickman catheter.

  12. Successive bacteremias with "Campylobacter cinaedi" and "Campylobacter fennelliae" in a bisexual male.

    OpenAIRE

    Ng, V L; Hadley, W K; Fennell, C L; Flores, B. M.; Stamm, W. E.

    1987-01-01

    A bisexual human immunodeficiency virus-seropositive male had successive bacteremias with "Campylobacter cinaedi" and "Campylobacter fennelliae." Because final identification of both isolates was not completed until 1 month after the last admission of the patient, a novel and nonstandardized antimicrobial susceptibility testing method was useful in guiding timely antimicrobial therapy.

  13. Incidence of bacteremia after chewing, tooth brushing and scaling in individuals with periodontal inflammation

    DEFF Research Database (Denmark)

    Forner, Lone; Larsen, Tove; Kilian, Mogens;

    2006-01-01

    higher in periodontitis than in gingivitis patients and healthy control individuals. In periodontitis patients, the magnitude of bacteremia was associated with gingival index, plaque index and number of sites with bleeding on probing, but not with probing pocket depth measurements. PRACTICAL IMPLICATIONS...

  14. Incidence of bacteremia after chewing, tooth brushing and scaling in individuals with periodontal inflammation

    DEFF Research Database (Denmark)

    Larsen, F.L.; Kilian, Mogens; Holmstrup, P.

    2006-01-01

    higher in periodontitis than in gingivitis patients and healthy control individuals. In periodontitis patients, the magnitude of bacteremia was associated with gingival index, plaque index and number of sites with bleeding on probing, but not with probing pocket depth measurements. Practical implications...

  15. Multidrug-Resistant Bacteroides fragilis Bacteremia in a US Resident: An Emerging Challenge

    Directory of Open Access Journals (Sweden)

    Cristian Merchan

    2016-01-01

    Full Text Available We describe a case of Bacteroides fragilis bacteremia associated with paraspinal and psoas abscesses in the United States. Resistance to b-lactam/b-lactamase inhibitors, carbapenems, and metronidazole was encountered despite having a recent travel history to India as the only possible risk factor for multidrug resistance. Microbiological cure was achieved with linezolid, moxifloxacin, and cefoxitin.

  16. Clinical importance and cost of bacteremia caused by nosocomial multi drug resistant acinetobacter baumannii

    Directory of Open Access Journals (Sweden)

    Tugba Arslan Gulen

    2015-09-01

    Conclusion: Our results suggest that the occurrence of MDR A.baumannii bacteremia was related with the usage of the wide spectrum antibiotics, and mortality rates were increased in patients that high SAPS II scores, long term hospitalization. Infection control procedures and limited antibiotic usage are very important for prevent nosocomial infections.

  17. Nonspecific Erysipelothrix rhusiopathiae Bacteremia in a Patient with Subclinical Alcoholic Liver Disease

    Directory of Open Access Journals (Sweden)

    Asim Ahmed Kichloo

    2013-01-01

    Full Text Available Erysipelothrix rhusiopathiae, a pleomorphic gram-positive bacillus, is found widely in nature or as a commensal pathogen. It infects domestic animals such as swine, which may be the major reservoir of the organism. E. rhusiopathiae is primarily an occupational illness; 89% of the cases are linked to high-risk epidemiological situations. Humans that are infected by this bacillus typically present with one or a combination of the following symptoms: localized skin lesion (erysipeloid, diffuse cutaneous eruptions with systemic symptoms, or bacteremia, which is often followed by endocarditis. We report a case of E. rhusiopathiae bacteremia that was present without severe clinical illness such as endocarditis, arthritis, or skin lesions. The patient was a 64-year-old male with a complicated past medical history including subclinical alcoholic liver disease. Penicillin-G therapy completely resolved the patients bacteremia. The case presented has exceptional clinical merit due to 2 key factors: the patient does not fit the occupational demographic typically affected by this bacterium, and the patient presented with subclinical septicemia, which has a high correlation with fatal endocarditis. This case brings a new prospective to E. rhusiopathiae bacteremia.

  18. Multidrug-Resistant Bacteroides fragilis Bacteremia in a US Resident: An Emerging Challenge

    Science.gov (United States)

    Parajuli, Sunita; Siegfried, Justin; Dubrovskaya, Yanina; Rahimian, Joseph

    2016-01-01

    We describe a case of Bacteroides fragilis bacteremia associated with paraspinal and psoas abscesses in the United States. Resistance to b-lactam/b-lactamase inhibitors, carbapenems, and metronidazole was encountered despite having a recent travel history to India as the only possible risk factor for multidrug resistance. Microbiological cure was achieved with linezolid, moxifloxacin, and cefoxitin. PMID:27418986

  19. Catheter-Related Bacteremia Due to Kocuria kristinae in a Patient with Ovarian Cancer

    OpenAIRE

    Basaglia, G.; Carretto, E; D. Barbarini; Moras, L.; Scalone, S; Marone, P; P. De Paoli

    2002-01-01

    We report on the first case of a catheter-related recurrent bacteremia caused by Kocuria kristinae, a gram-positive microorganism belonging to the family Micrococcaceae, in a 51-year-old woman with ovarian cancer. This unusual pathogen may cause opportunistic infections in patients with severe underlying diseases.

  20. Does the empiric use of vancomycin in pediatrics increase the risk for Gram-negative bacteremia?

    NARCIS (Netherlands)

    Cuno, SPMU; Heesen, GJM; Arends, JP; Kimpen, JLL; van Houten, M.A.

    2001-01-01

    Background, Gram-negative bacteremia in children, a major cause of morbidity and mortality, may in part be induced by intensive treatment procedures and nonspecific use of antibiotics. Our primary objective was to study the causal relationship between the use of vancomycin and Gram-negative bacterem

  1. First clinical description of Eggerthia catenaformis bacteremia in a patient with dental abscess

    DEFF Research Database (Denmark)

    Kordjian, Hayarpi H; Schultz, Joyce D J H; Rosenvinge, Flemming Schønning;

    2015-01-01

    We present a case of Eggerthia catenaformis bacteremia originating from a dental abscess and imitating necrotizing fasciitis in a previously healthy adult. The isolates were easily identified by MALDI-TOF MS. The clinical course, surgical and antibiotic treatment as well as the successful outcome...

  2. Influence of Host Genetics and Environment on Nasal Carriage of Staphylococcus aureus in Danish Middle-Aged and Elderly Twins

    DEFF Research Database (Denmark)

    Andersen, Paal Skytt; Pedersen, Jacob Krabbe; Fode, Peder;

    2012-01-01

    Background. Nasal carriage is a major risk factor for Staphylococcus aureus infection. Approximately, one-quarter of adults carry S. aureus. However, the role of host genetics on S. aureus nasal carriage is unknown. Methods. Nasal swabs were obtained from a national cohort of middle-aged and elde......Background. Nasal carriage is a major risk factor for Staphylococcus aureus infection. Approximately, one-quarter of adults carry S. aureus. However, the role of host genetics on S. aureus nasal carriage is unknown. Methods. Nasal swabs were obtained from a national cohort of middle.......4%-34.5%), and opposite sex (21.4%; 95% CI, 12.0%-33.4%) dizygotic twins. Despite shared childhoods, only 1 of 617 pairs was concordant with respect to lineage. Although heritability increased for S. aureus and lineage persistency, no significant heritability was detected. Conclusion. In this study, host genetic factors...

  3. Time to positivity in blood cultures of adults with Streptococcus pneumoniae bacteremia

    Directory of Open Access Journals (Sweden)

    Ansorena Luis

    2006-04-01

    Full Text Available Abstract Background previous studies have established that bacterial blood concentration is related with clinical outcome. Time to positivity of blood cultures (TTP has relationship with bacterial blood concentration and could be related with prognosis. As there is scarce information about the usefulness of TTP, we study the relationship of TTP with clinical parameters in patients with Streptococcus pneumoniae bacteremia. Methods TTP of all cases of Streptococcus pneumoniae bacteremia, detected between January 1995 and December 2004 using the BacT/Alert automated blood culture system in a teaching community hospital was analyzed. When multiple cultures were positive only the shortest TTP was selected for the analysis. Results in the study period 105 patients with Streptococcus pneumoniae bacteremia were detected. Median TTP was 14.1 hours (range 1.2 h to 127 h. Immunosuppressed patients (n = 5, patients with confusion (n = 19, severe sepsis or shock at the time of blood culture extraction (n = 12, those with a diagnosis of meningitis (n = 7 and those admitted to the ICU (n = 14 had lower TTP. Patients with TTP in the first quartile were more frequently hospitalized, admitted to the ICU, had meningitis, a non-pneumonic origin of the bacteremia, and a higher number of positive blood cultures than patients with TTP in the fourth quartile. None of the patients with TTP in the 90th decile had any of these factors associated with shorter TTP, and eight out of ten patients with TTP in the 10th decile had at least one of these factors. The number of positive blood cultures had an inverse correlation with TTP, suggesting a relationship of TTP with bacterial blood concentration. Conclusion Our data support the relationship of TTP with several clinical parameters in patients with Streptococcus pneumoniae bacteremia, and its potential usefulness as a surrogate marker of outcome.

  4. Comparison of radiometric and conventional culture systems in detecting Haemophilus influenzae type b bacteremia in rats

    International Nuclear Information System (INIS)

    To compare the efficiency of detecting Haemophilus influenzae type b bacteremia by the BACTEC radiometric system and a conventional Trypticase soy broth blood culture system, the authors developed an in vivo model of bacteremia in rats. After intravenous injection of 50 to 200 CFU into adult rats, there was a linear logarithmic increase in CFU per milliliter of rat blood during the first 10 h (r = 0.98), allowing accurate prediction of the level of bacteremia with time. Culture bottles were inoculated with 0.5 ml of blood obtained by cardiac puncture and processed as clinical samples in the microbiology laboratory with RS and conventional protocols. They found the following. (i) The first detection of bacteremia by RS was similar to that by TSB if a Gram stain of the TSB was done on day 1 and was superior if that smear was omitted (P less than 0.01). (ii) The detection times in both systems were comparable at different magnitudes of bacteremia (10(1) to 10(4) CFU/ml). (iii) Supplementation of inoculated bottles with 2 ml of sterile rat blood interfered with Gram stain detection in TSB but resulted in increased 14CO2 production in RS. (iv) No difference in detection time was found between RS and TSB for four different clinical isolates. These studies show that, in a biologically relevant model, the detection of positive blood cultures for H. influenzae type b by RS was comparable to or better than detection by TSB when blood was processed analogously to clinical specimens

  5. Differential Analysis of the Nasal Microbiome of Pig Carriers or Non-Carriers of Staphylococcus aureus

    DEFF Research Database (Denmark)

    Espinosa-Gongora, Carmen; Larsen, Niels; Schonning, Kristian;

    2016-01-01

    pathogen in animal carriers. The aim of this study was to determine whether the nasal microbiome of pig S. aureus carriers differs from that of non-carriers. The V3-V5 region of the 16S rRNA gene was sequenced from nasal swabs of 44 S. aureus carriers and 56 non-carriers using the 454 GS FLX titanium...... microbiome of pigs that are not colonized with S. aureus harbours several species/taxa that are significantly less abundant in pig carriers, suggesting that the nasal microbiota may play a role in the individual predisposition to S. aureus nasal carriage in pigs. Further research is warranted to isolate...

  6. Pattern differentiation in co-culture biofilms formed by Staphylococcus aureus and Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Yang, Liang; Liu, Yang; Markussen, Trine;

    2011-01-01

    important for understanding of biofilm physiology and the treatment of biofilm-related infectious diseases. Here, we have investigated interactions of two of the major bacterial species of cystic fibrosis lung microbial communities -Pseudomonas aeruginosa and Staphylococcus aureus- when grown in co......-culture biofilms. By growing co-culture biofilms of S. aureus with P. aeruginosa mutants in a flow-chamber system and observing them using confocal laser scanning microscopy, we show that wild-type P. aeruginosa PAO1 facilitates S. aureus microcolony formation. In contrast, P. aeruginosa mucA and rpoN mutants do...... not facilitate S. aureus microcolony formation and tend to outcompete S. aureus in co-culture biofilms. Further investigations reveal that extracellular DNA (eDNA) plays an important role in S. aureus microcolony formation and that P. aeruginosa type IV pili are required for this process, probably through...

  7. Avaliação in vitro da atividade antibacteriana da água ozonizada frente ao Staphylococcus aureus In vitro evaluation of the antibacterial activity of ozonized water against Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Helena Engel VELANO

    2001-03-01

    Full Text Available O Staphylococcus aureus faz parte da microbiota da pele, mucosas e nasofaringe de várias espécies animais, incluindo o homem, mas também está associado a enfermidades como abscessos, bacteremias, endocardites e osteomielites, além de se mostrar resistente a múltiplas drogas. Este trabalho foi realizado com a finalidade de avaliar o efeito do gás ozônio, dissolvido em água, sobre o S. aureus. Foram preparadas suspensões de S. aureus, com concentrações variando de 10(6 a 10(16 microrganismos/ml. De cada suspensão recém-preparada foi retirado 1 ml e adicionado a 99 ml de água destilada estéril (com ou sem prévia ozonização, em um reator de cristal. Foram preparadas diluições seriadas (1/10 das suspensões testadas e inoculado 0,1 ml de cada suspensão em Tryptic Soy Agar, incubadas a 37ºC por 24 h, quando então se procedeu à contagem das UFC. Os resultados obtidos mostraram que o tempo máximo para a inativação total das bactérias tratadas com água previamente ozonizada (0,6 mg/ml foi de 5’25" e, para a água não previamente ozonizada, foi de 23’45", indicando um efeito antibacteriano mais rápido da água previamente ozonizada, frente ao S. aureus.Staphylococcus aureus belongs to the normal flora of the skin, mucosa and nasopharynx of several animal species, including man, but it is also associated to illnesses such as abscesses, bacteremia, endocarditis and osteomyelitis, besides showing resistance to multiple drugs. The purpose of this paper was to evaluate the disinfecting ability of ozone when dissolved in water. Suspensions of Staphylococcus aureus with concentrations varying from 10(6 to 10(16 microorganisms/ml were prepared. One milliliter of each recently prepared suspension was added to 99 ml of distilled water (with or without previous ozonization contained in a crystal reactor. Aliquots of 0.1 ml of this new suspension were taken at various time intervals and, then, serially diluted and inoculated on

  8. Toxin-Antitoxin Systems of Staphylococcus aureus.

    Science.gov (United States)

    Schuster, Christopher F; Bertram, Ralph

    2016-05-05

    Toxin-antitoxin (TA) systems are small genetic elements found in the majority of prokaryotes. They encode toxin proteins that interfere with vital cellular functions and are counteracted by antitoxins. Dependent on the chemical nature of the antitoxins (protein or RNA) and how they control the activity of the toxin, TA systems are currently divided into six different types. Genes comprising the TA types I, II and III have been identified in Staphylococcus aureus. MazF, the toxin of the mazEF locus is a sequence-specific RNase that cleaves a number of transcripts, including those encoding pathogenicity factors. Two yefM-yoeB paralogs represent two independent, but auto-regulated TA systems that give rise to ribosome-dependent RNases. In addition, omega/epsilon/zeta constitutes a tripartite TA system that supposedly plays a role in the stabilization of resistance factors. The SprA1/SprA1AS and SprF1/SprG1 systems are post-transcriptionally regulated by RNA antitoxins and encode small membrane damaging proteins. TA systems controlled by interaction between toxin protein and antitoxin RNA have been identified in S. aureus in silico, but not yet experimentally proven. A closer inspection of possible links between TA systems and S. aureus pathophysiology will reveal, if these genetic loci may represent druggable targets. The modification of a staphylococcal TA toxin to a cyclopeptide antibiotic highlights the potential of TA systems as rather untapped sources of drug discovery.

  9. The relation between Staphylococcus aureus and Wegener's granulomatosis : Current knowledge and future directions

    NARCIS (Netherlands)

    Popa, ER; Tervaert, JWC

    2003-01-01

    To date, in the investigation of the role of S. aureus in WG, we face a paradoxical situation. On the one hand, clinical results obtained from treatment of WG patients with co-trimoxazole and studies assessing the impact of S. aureus on disease relapses strongly suggest that this bacterium contribut

  10. Linezolid resistant Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Pavani Gandham

    2014-08-01

    Full Text Available Linezolid is the only antibiotic available as an oral formulation for resistant staphylococcal infections. It is effective in skin and soft tissue infections, nosocomial pneumonias including VAP, infective endocarditis and MRSA meningitis. It is also effective in the eradication of both nasal and throat colonization of MRSA. Its high bioavailability and post antibiotic effect, ease of switching to oral therapy during its use and the fact that it can be used in patients of all ages, also in patients with liver disease and poor kidney function and its increased effectiveness over glycopeptides makes this drug a precious drug in the treatment of resistant staphylococcal infections. Linezolid resistance in staphylococcus is defined as a linezolid MIC of and #8805;8 mg/L. Reported Linezolid resistance in India and elsewhere is 2-20%. There is clonal dissemination of Linezolid Resistant Staphylococcus aureus (LRSA within or across health care settings which demands continuous surveillance to determine the emergent risk of resistance strains and to establish guidelines for appropriate use. Clinical laboratories should confirm any LRSA preferably by a second method, prior to using linezolid for serious infections. Effective surveillance, more judicious use of this antibiotic, avoiding linezolid usage for empiric therapy in hospital acquired staphylococcus infections, optimization of the pharmacological parameters of the antibiotics in specific clinical situation, decreasing bacterial load by timely surgical debridement or drainage of collections, use of combination therapies would prevent the emergence of resistance to linezolid in staphylococcus aureus. [Int J Res Med Sci 2014; 2(4.000: 1253-1256

  11. Value of soluble TREM-1, procalcitonin, and C-reactive protein serum levels as biomarkers for detecting bacteremia among sepsis patients with new fever in intensive care units: a prospective cohort study

    Directory of Open Access Journals (Sweden)

    Su Longxiang

    2012-07-01

    Full Text Available Abstract Background The purpose of this study was to explore the diagnostic value of soluble triggering receptor expressed on myeloid cells 1 (sTREM-1, procalcitonin (PCT, and C-reactive protein (CRP serum levels for differentiating sepsis from SIRS, identifying new fever caused by bacteremia, and assessing prognosis when new fever occurred. Methods We enrolled 144 intensive care unit (ICU patients: 60 with systemic inflammatory response syndrome (SIRS and 84 with sepsis complicated by new fever at more than 48 h after ICU admission. Serum sTREM-1, PCT, and CRP levels were measured on the day of admission and at the occurrence of new fever (>38.3°C during hospitalization. Based on the blood culture results, the patients were divided into a blood culture-positive bacteremia group (33 patients and blood culture-negative group (51 patients. Based on 28-day survival, all patients, both blood culture-positive and -negative, were further divided into survivor and nonsurvivor groups. Results On ICU day 1, the sepsis group had higher serum sTREM-1, PCT, and CRP levels compared with the SIRS group (P P Conclusions Serum sTREM-1, PCT, and CRP levels each have a role in the early diagnosis of sepsis. Serum sTREM-1, with the highest sensitivity and specificity of all indicators studied, is especially notable. sTREM-1, PCT, and CRP levels are of no use in determining new fever caused by bacteremia in ICU patients, but sTREM-1 levels reflect the prognosis of bacteremia. Trial registration ClinicalTrial.gov identifier NCT01410578

  12. Naturally occurring IgG antibody levels to the Staphylococcus aureus protein IsdB in humans.

    Science.gov (United States)

    Zorman, Julie K; Esser, Mark; Raedler, Michael; Kreiswirth, Barry N; Ala'Aldeen, Dlawer A A; Kartsonis, Nicholas; Smugar, Steven S; Anderson, Annaliesa S; McNeely, Tessie; Arduino, Jean Marie

    2013-09-01

    Staphylococcus aureus is a well-recognized, clinically important cause of nosocomial infections, and as such, a vaccine to prevent S. aureus infections would be an important achievement. A Phase IIB/III study of V710, a vaccine containing iron-regulated surface determinant B (IsdB), demonstrated significant sero-conversion rates in cardiovascular surgery patients following a single pre-surgery immunization. However, the vaccine was not efficacious in preventing bacteremia or deep sternal wound infection post-surgery, thus raising the possibility that IsdB might not be available for immune recognition during infection. The purpose of the work described herein was to evaluate and quantify the naturally occurring anti-IsdB levels at baseline and over time during infection, to understand whether IsdB is expressed during a S. aureus infection in hospitalized non-vaccinated patients. We evaluated baseline and follow-up titers in 3 populations: (1) healthy subjects, (2) hospitalized patients with non-S. aureus infections, and (3) hospitalized patients with S. aureus infections. Baseline anti-IsdB levels generally overlapped between the 3 groups, but were highly variable within each group. In healthy subjects, baseline and follow-up levels were highly correlated (Spearman's rho = 0.93), and the geometric mean fold-rise (GMFR) in anti-IsdB levels between study entry and last value was 0.9-fold (95% confidence interval (CI): 0.8 to 1.0 ; p = 0.09), showing no trend over time. The convalescent GMFR in anti-IsdB levels from baseline was 1.7-fold (95% CI: 1.3 to 2.2, p = 0.0008) during S. aureus infection, significantly different from the 1.0-fold GMFR (95% CI: 0.9-1.2, p = 0.60) in non-S. aureus infection, p = 0.005. Additionally, S. aureus isolates (51) obtained from the hospitalized patient group expressed the IsdB protein in vitro. Collectively, these data suggest that IsdB expression levels rise substantially following infection with S. aureus, but not with other pathogens

  13. Two novel point mutations in clinical Staphylococcus aureus reduce linezolid susceptibility and switch on the stringent response to promote persistent infection.

    Directory of Open Access Journals (Sweden)

    Wei Gao

    Full Text Available Staphylococcus aureus frequently invades the human bloodstream, leading to life threatening bacteremia and often secondary foci of infection. Failure of antibiotic therapy to eradicate infection is frequently described; in some cases associated with altered S. aureus antimicrobial resistance or the small colony variant (SCV phenotype. Newer antimicrobials, such as linezolid, remain the last available therapy for some patients with multi-resistant S. aureus infections. Using comparative and functional genomics we investigated the molecular determinants of resistance and SCV formation in sequential S. aureus isolates from a patient who had a persistent and recurrent S. aureus infection, after failed therapy with multiple antimicrobials, including linezolid. Two point mutations in key staphylococcal genes dramatically affected clinical behaviour of the bacterium, altering virulence and antimicrobial resistance. Most strikingly, a single nucleotide substitution in relA (SACOL1689 reduced RelA hydrolase activity and caused accumulation of the intracellular signalling molecule guanosine 3', 5'-bis(diphosphate (ppGpp and permanent activation of the stringent response, which has not previously been reported in S. aureus. Using the clinical isolate and a defined mutant with an identical relA mutation, we demonstrate for the first time the impact of an active stringent response in S. aureus, which was associated with reduced growth, and attenuated virulence in the Galleria mellonella model. In addition, a mutation in rlmN (SACOL1230, encoding a ribosomal methyltransferase that methylates 23S rRNA at position A2503, caused a reduction in linezolid susceptibility. These results reinforce the exquisite adaptability of S. aureus and show how subtle molecular changes cause major alterations in bacterial behaviour, as well as highlighting potential weaknesses of current antibiotic treatment regimens.

  14. Biofilm formation and genotyping of Staphylococcus aureus bovine mastitis isolates: Evidence for lack of penicillin-resistance in Agr-type II strains

    NARCIS (Netherlands)

    Melchior, M.B.; Osch, M.H.J.; Graat, R.; Duijkeren, van E.; Mevius, D.J.; Nielen, M.; Gaastra, W.; Fink, J.

    2009-01-01

    The increasing evidence for a role of biofilm formation in bovine mastitis caused by Staphylococcus aureus led to further investigations on biofilm formation by S. aureus isolates from mastitis in two growth media (TSBg and bovine milk serum). The ability of 99 S. aureus strains that were recently i

  15. Biofilm formation and genotyping of Staphylococcus aureus bovine mastitis isolates: evidence for lack of penicillin-resistance in Agr-type II strains.

    NARCIS (Netherlands)

    Melchior, M.B.; van Osch, M.H.J.; Graat, R.M.; van Duijkeren, E.; Mevius, D.J.; Nielen, M.; Gaastra, W.; Fink-Gremmels, J.

    2009-01-01

    The increasing evidence for a role of biofilm formation in bovine mastitis caused by Staphylococcus aureus led to further investigations on biofilm formation by S. aureus isolates from mastitis in two growth media (TSBg and bovine milk serum). The ability of 99 S. aureus strains that were recently i

  16. Staphylococcus aureus triggered reactive arthritis.

    OpenAIRE

    Siam, A R; M. Hammoudeh

    1995-01-01

    OBJECTIVES--To report two patients who developed reactive arthritis in association with Staphylococcus aureus infection. METHODS--A review of the case notes of two patients. RESULTS--Two adult female patients have developed sterile arthritis in association with Staph aureus infection. The first patient has had two episodes of arthritis; the first followed olecranon bursitis, the second followed infection of a central venous catheter used for dialysis. The second patient developed sterile arth...

  17. International travel and the risk of hospitalization with non-typhoidal Salmonella bacteremia. A Danish population-based cohort study, 1999-2008

    OpenAIRE

    Mølbak Kåre; Ethelberg Steen; Holt Hanne M; Kristensen Brian; Koch Kristoffer; Schønheyder Henrik C

    2011-01-01

    Abstract Background Information is sparse regarding the association between international travel and hospitalization with non-typhoidal Salmonella bacteremia. The aim of this study was to determine the proportion, risk factors and outcomes of travel-related non-typhoidal Salmonella bacteremia. Methods We conducted a 10-year population-based cohort study of all patients hospitalized with non-typhoidal Salmonella bacteremia in three Danish counties (population 1.6 million). We used denominator ...

  18. Serum procalcitonin elevation in critically ill patients at the onset of bacteremia caused by either gram negative or gram positive bacteria

    Directory of Open Access Journals (Sweden)

    Prin Sébastien

    2008-03-01

    Full Text Available Abstract Background In the ICU, bacteremia is a life-threatening infection whose prognosis is highly dependent on early recognition and treatment with appropriate antibiotics. Procalcitonin levels have been shown to distinguish between bacteremia and noninfectious inflammatory states accurately and quickly in critically ill patients. However, we still do not know to what extent the magnitude of PCT elevation at the onset of bacteremia varies according to the Gram stain result. Methods Review of the medical records of every patient treated between May, 2004 and December, 2006 who had bacteremia caused by either Gram positive (GP or Gram negative (GN bacteria, and whose PCT dosage at the onset of infection was available. Results 97 episodes of either GN bacteremia (n = 52 or GP bacteremia (n = 45 were included. Procalcitonin levels were found to be markedly higher in patients with GN bacteremia than in those with GP bacteremia, whereas the SOFA score value in the two groups was similar. Moreover, in the study population, a high PCT value was found to be independently associated with GN bacteremia. A PCT level of 16.0 ng/mL yielded an 83.0% positive predictive value and a 74.0% negative predictive value for GN-related bacteremia in the study cohort (AUROCC = 0.79; 95% CI, 0.71–0.88. Conclusion In a critically ill patient with clinical sepsis, GN bacteremia could be associated with higher PCT values than those found in GP bacteremia, regardless of the severity of the disease.

  19. Evaluating antibiotic stewardship programs in patients with bacteremia using administrative data

    DEFF Research Database (Denmark)

    Boel, J; Søgaard, M; Andreasen, V;

    2015-01-01

    of treatment, and computed adjusted hazard ratios (HRs) and 95 % confidence intervals (CIs) for 30-day mortality and post-discharge readmission by regimen and appropriateness of treatment. In total, 945 (47.1 %) were treated by the old regimen and 1,063 (52.9 %) by the new. The median length of stay (8 days...... treatment. We categorized 2,008 adult patients diagnosed with bacteremia between 2010 and 2012 according to whether they received cephalosporins or fluoroquinolones (old regimen) or not (new regimen). We used administrative data to extract individual level data on mortality, readmission, and appropriateness......When introducing new antibiotic guidelines for empirical treatment of bacteremia, it is imperative to evaluate the performance of the new guideline. We examined the utility of administrative data to evaluate the effect of new antibiotic guidelines and the prognostic impact of appropriate empirical...

  20. [Rare infection--prolonged A. naeslundii bacteremia caused by severe caries].

    Science.gov (United States)

    Abozaid, Said; Peretz, Avi; Nasser, Wael; Zarfin, Yehoshua

    2013-07-01

    Actinomyces is an anaerobic, gram positive, rod shape bacteria that doesn't create spores. Actinomyces is part of the mouth, intestines, vagina and upper respiratory system flora. The infection appears mostly on the face, neck, abdomen and pelvis in cases of mucosa injury and most common in immunosuppressed patients. The spread of Actinomyces through the blood system is rare. In this article we present a 9 year old male patient with no history of diseases who was diagnosed with prolonged bacteremia of A. naeslundii without specific infection excluding severe caries. Characterization of bacteria from the blood culture was performed by molecular biology and the patient was treated with Ampicillin and tooth extraction that led to the disappearance of the bacteremia. PMID:23957079

  1. The effect of S. pneumoniae bacteremia on cerebral blood flow autoregulation in rats

    DEFF Research Database (Denmark)

    Pedersen, Michael; Brandt, Christian T.; Knudsen, Gitte Moos;

    2008-01-01

    In the present study, we studied the effect of bacteremia on cerebral blood flow (CBF) autoregulation in a rat model of pneumococcal bacteremia and meningitis. Anesthetized rats were divided into five groups (A to E) and inoculated with pneumococci intravenously and normal saline intracisternally......); or saline intravenously and saline intracisternally (group E, N=10), respectively. Positive cultures occurred in the blood for all rats in groups A, B, and C, and in the cerebrospinal fluid for all rats in groups D and E. Twenty-four hours after inoculation, CBF was measured with laser-Doppler ultrasound...... during incremental reductions in cerebral perfusion pressure (CPP) by controlled hemorrhage. Autoregulation was preserved in all rats without meningitis (groups A and E) and was lost in 24 of 25 meningitis rats (groups B, C, and D) (P

  2. Staphylococcus aureus small colony variants in diabetic foot infections

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    Estrella Cervantes-García

    2015-03-01

    Full Text Available Background: Staphylococcus aureus (S. aureus is one of the major pathogens causing chronic infections. The ability of S. aureus to acquire resistance to a diverse range of antimicrobial compounds results in limited treatment options, particularly in methicillin-resistant S. aureus (MRSA. A mechanism by which S. aureus develops reduced susceptibility to antimicrobials is through the formation of small colony variants (SCVs. Infections by SCVs of S. aureus are an upcoming problem due to difficulties in laboratory diagnosis and resistance to antimicrobial therapy. Methods: A prospective study was performed on 120 patients diagnosed with both type 2 diabetes mellitus and infected diabetic foot ulcers. The study was carried out from July 2012 to December 2013 in Hospital General de Mexico. The samples were cultured in blood agar, mannitol salt agar, and MacConkey agar media, and incubated at 37°C in aerobic conditions. Results: We describe the first known cases of diabetic foot infections caused by MRSA-SCVs in patients diagnosed with type 2 diabetes mellitus and infected diabetic foot ulcers. In all of our cases, the patients had not received any form of gentamicin therapy. Conclusions: The antibiotic therapy commonly used in diabetic patients with infected diabetic foot ulcers fails in the case of MRSA-SCVs because the intracellular location protects S. aureus-SCVs from the host's defenses and also helps them resist antibiotics. The cases studied in this article add to the spectrum of persistent and relapsing infections attributed to MRSA-SCVs and emphasizes that these variants may also play a relevant role in diabetic foot infections.

  3. Mortality attributable to carbapenem-resistant Pseudomonas aeruginosa bacteremia: a meta-analysis of cohort studies

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    Zhang, Yu; Chen, Xiao-Li; Huang, Ai-Wei; Liu, Su-Ling; Liu, Wei-Jiang; Zhang, Ni; Lu, Xu-Zai

    2016-01-01

    Whether carbapenem resistance is associated with mortality in patients with Pseudomonas aeruginosa bacteremia is controversial. To address this issue, we conducted a systematic review and meta-analysis based on cohort studies. We searched PubMed and Embase databases to identify articles (up to April 2015). The DerSimonian and Laird random-effect model was used to generate a summary estimate of effect. Associations were evaluated in subgroups based on different patient characteristics and study quality criteria. Seven studies with a total of 1613 patients were finally included, of which 1 study had a prospective design, and the other 6 were retrospective. Our meta-analysis showed patients with carbapenem-resistant P. aeruginosa bacteremia were at a higher risk of death compared with those with carbapenem-susceptible P. aeruginosa bloodstream infections (pooled odds ratio (OR) from three studies reporting adjusted ORs: 3.07, 95% confidence interval (CI), 1.60–5.89; pooled OR from 4 studies only reporting crude ORs: 1.46, 95% CI, 1.10–1.94). The results were robust across a number of stratified analyses and a sensitivity analysis. We also calculated that 8%–18.4% of deaths were attributable to carbapenem resistance in four studies assessing the outcome with 30-day mortality, and these were 3% and 14.6%, respectively, in two studies using 7-day mortality or mortality during bacteremia as an outcome of interest. Carbapenem resistance had a deleterious impact on the mortality of P. aeruginosa bacteremia; however, the results should be interpreted cautiously because only three studies reporting adjusted ORs were included. More large-scale, well-designed prospective cohorts, as well as mechanistic studies, are urgently needed in the future. PMID:27004762

  4. Neurological complications after neonatal bacteremia: the clinical characteristics, risk factors, and outcomes.

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    Shih-Ming Chu

    Full Text Available BACKGROUND: Neonates with bacteremia are at risk of neurologic complications. Relevant information warrants further elucidation. STUDY DESIGN: This was a retrospective cohort study of neonates with bacteremia-related neurologic complications (BNCs in a tertiary-level neonatal intensive care unit (NICU. A systemic chart review was performed conducted to identify clinical characteristics and outcomes. A cohort of related conditions was constructed as the control group. Logistic regression analysis was used to identify independent risk factors for BNC. RESULTS: Of 1037 bacteremia episodes, 36 (3.5% had BNCs. Twenty-four cases of BNCs were related to meningitis, five were presumed meningitis, and seven occurred after septic shock. The most common causative pathogens were Group B streptococcus (41.7% and E. coli (16.7%. The major BNCs consisted of seizures (28, hydrocephalus (20, encephalomalacia (11, cerebral infarction (7, subdural empyema (6, ventriculitis (8, and abscess (4. Eight (22.8% neonates died and six (16.7% were discharged in critical condition when the family withdrew life-sustaining treatment. Among the 22 survivors, eight had neurologic sequelae upon discharge. After multivariate logistic regression analysis, neonates with meningitis caused by Group B streptococcus (adjusted odds ratio [OR]: 8.90, 95% confidence interval [CI]: 2.20-36.08; p = 0.002 and combined meningitis and septic shock (OR, 5.94; 95% CI: 1.53-23.15; p = 0.010 were independently associated with BNCs. CONCLUSIONS: Neonates with bacteremia-related neurologic complications are associated with adverse outcomes or sequelae. Better strategies aimed at early detection and reducing the emergence of neurologic complications and aggressive treatment of Group B streptococcus sepsis are needed in neonates with meningitis and septic shock.

  5. Staphylococcus pettenkoferi Bacteremia: A Case Report and Review of the Literature

    OpenAIRE

    Abdulaziz Ahmed Hashi; Johannes Andries Delport; Sameer Elsayed; Michael Seth Silverman

    2015-01-01

    Staphylococcus pettenkoferi is a relatively recently described coagulase-negative staphylococci species first described in 2002. Since then, nine additional cases of infection caused by this species have been reported in various countries around the world, including Germany, Belgium, France, South Korea, Italy, Brazil and Mexico. The present report describes a case of S pettenkoferi peripheral line-associated bacteremia. To our knowledge, the present report is the first description of human i...

  6. Minocycline-EDTA Lock Solution Prevents Catheter-Related Bacteremia in Hemodialysis

    OpenAIRE

    Campos, Rodrigo Peixoto; do Nascimento, Marcelo Mazza; Chula, Domingos Candiota; Riella, Miguel Carlos

    2011-01-01

    There is growing concern about the development of antibacterial resistance with the use of antibiotics in catheter lock solutions. The use of an antibiotic that is not usually used to treat other serious infections may be an alternative that may reduce the clinical impact should resistance develop. We conducted a randomized controlled trial to compare a solution of minocycline and EDTA with the conventional unfractionated heparin for the prevention of catheter-related bacteremia in hemodialys...

  7. A rare bacteremia caused by Cedecea davisae in patient with chronic renal disease

    OpenAIRE

    Peretz, Avi; Simsolo, Claudia; Farber, Evgeny; Roth, Anna; Brodsky, Diana; Nakhoul, Farid

    2013-01-01

    Patient: Female, 77 Final Diagnosis: Bacteremia Symptoms: Chills • diarrhea • fever • nausea Medication: — Clinical Procedure: X-Ray • CBC • urine and blood cultur Specialty: Infectious diseases Objective: Rare disease Background: Cedecea davisae is a gram negative, oxidase negative bacilli that include 5 species. In the medical literature there are very few reports that describe infections caused by different species of the Cedecea genus. Case Report: In this paper we report a fourth case of...

  8. Carbapenem Breakpoints for Acinetobacter baumannii Group: Supporting Clinical Outcome Data from Patients with Bacteremia.

    Science.gov (United States)

    Lee, Yi-Tzu; Chiang, Mei-Chun; Kuo, Shu-Chen; Wang, Yung-Chih; Lee, I-Hsin; Chen, Te-Li; Yang, Ya-Sung

    2016-01-01

    The carbapenem breakpoints set by different organizations for Acinetobacter are discordant, but supporting clinical data are lacking. This study aimed to provide the first clinical outcome data to support the carbapenem breakpoints for Acinetobacter baumannii (Ab) group in patients with bacteremia. This study included 117 adults who received carbapenems for treatment of Ab group bacteremia in Taipei Veterans General Hospital over an 8-year period. We analyzed 30-day mortality rates among patient groups acquiring isolates with different carbapenem minimal inhibitory concentrations (MICs). The carbapenem MIC breakpoint derived from classification and regression tree (CART) analysis to delineate the risk of 30-day mortality was between MICs of ≤ 4 mg/L and ≥ 8 mg/L. Mortality rate was higher in patients acquiring isolates with carbapenem MIC ≥ 8 mg/L than ≤ 4 mg/L, by bivariate (54.9% [28/51] vs 25.8% [17/66]; P = 0.003) and survival analysis (P = 0.001 by log-rank test). Multivariate analysis using logistic regression and Cox regression models including severity of illness indices demonstrated that treating patients with Ab group bacteremia caused by isolates with a carbapenem MIC ≥ 8 mg/L with carbapenem was an independent predictor of 30-day mortality (odds ratio, 5.125; 95% confidence interval [CI], 1.946-13.498; P = 0.001, and hazard ratio, 2.630; 95% CI, 1.431-4.834; P = 0.002, respectively). The clinical outcome data confirmed that isolates with MIC ≤ 4 mg/L were susceptible to carbapenem, and those with MIC ≥ 8 mg/L were resistant in patients with Ab group bacteremia. PMID:27644087

  9. Beta Lactamase Producing Clostridium perfringens Bacteremia in an Elderly Man with Acute Pancreatitis

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    Rashmi Mishra

    2016-01-01

    Full Text Available Clostridium perfringens bacteremia is associated with adverse outcomes. Known risk factors include chronic kidney disease, malignancy, diabetes mellitus, and gastrointestinal disease. We present a 74-year-old man admitted with confusion, vomiting, and abdominal pain. Exam revealed tachycardia, hypotension, lethargy, distended abdomen, and cold extremities. He required intubation and aggressive resuscitation for septic shock. Laboratory data showed leukocytosis, metabolic acidosis, acute kidney injury, and elevated lipase. CT scan of abdomen revealed acute pancreatitis and small bowel ileus. He was started on vancomycin and piperacillin-tazobactam. Initial blood cultures were positive for C. perfringens on day five. Metronidazole and clindamycin were added to the regimen. Repeat CT (day 7 revealed pancreatic necrosis. The patient developed profound circulatory shock requiring multiple vasopressors, renal failure requiring dialysis, and bacteremia with vancomycin-resistant enterococci. Hemodynamic instability precluded surgical intervention and he succumbed to multiorgan failure. Interestingly, our isolate was beta lactamase producing. We review the epidemiology, risk factors, presentation, and management of C. perfringens bacteremia. This case indicates a need for high clinical suspicion for clostridial sepsis and that extended spectrum beta lactam antibiotic coverage may be inadequate and should be supplemented with use of clindamycin or metronidazole if culture is positive, until sensitivities are known.

  10. Severe Sepsis due to Clostridium perfringens Bacteremia of Urinary Origin: A Case Report and Systematic Review.

    Science.gov (United States)

    Millard, Michael A; McManus, Kathleen A; Wispelwey, Brian

    2016-01-01

    Clostridium perfringens bacteremia is an uncommon yet serious clinical syndrome that typically arises from a gastrointestinal source. However, clinicians should consider nongastrointestinal sources as well. We present a rare case of C. perfringens bacteremia of urinary origin that required surgical intervention for definitive treatment. A 61-year-old male presented with acute nausea and vomiting, altered mental status, and chronic diarrhea. His physical exam revealed right costovertebral tenderness and his laboratory work-up revealed acute renal failure. Percutaneous blood cultures grew C. perfringens. Cross-sectional imaging revealed a right-sided ureteral stone with hydronephrosis, which required nephrostomy placement. On placement of the nephrostomy tube, purulent drainage was identified and Gram stain of the drainage revealed Gram-variable rods. A urinary source of C. perfringens was clinically supported. Although it is not a common presentation, nongastrointestinal sources such as a urinary source should be considered in C. perfringens bacteremia because failure to recognize a nongastrointestinal source can delay appropriate treatment, which may include surgical intervention. PMID:26998370

  11. Severe Sepsis due to Clostridium perfringens Bacteremia of Urinary Origin: A Case Report and Systematic Review

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    Michael A. Millard

    2016-01-01

    Full Text Available Clostridium perfringens bacteremia is an uncommon yet serious clinical syndrome that typically arises from a gastrointestinal source. However, clinicians should consider nongastrointestinal sources as well. We present a rare case of C. perfringens bacteremia of urinary origin that required surgical intervention for definitive treatment. A 61-year-old male presented with acute nausea and vomiting, altered mental status, and chronic diarrhea. His physical exam revealed right costovertebral tenderness and his laboratory work-up revealed acute renal failure. Percutaneous blood cultures grew C. perfringens. Cross-sectional imaging revealed a right-sided ureteral stone with hydronephrosis, which required nephrostomy placement. On placement of the nephrostomy tube, purulent drainage was identified and Gram stain of the drainage revealed Gram-variable rods. A urinary source of C. perfringens was clinically supported. Although it is not a common presentation, nongastrointestinal sources such as a urinary source should be considered in C. perfringens bacteremia because failure to recognize a nongastrointestinal source can delay appropriate treatment, which may include surgical intervention.

  12. [Case of Streptococcus salivarius bacteremia/meningoencephalitis leading to discovery of early gastric cancer].

    Science.gov (United States)

    Ijyuuin, Toshiro; Umehara, Fujio

    2012-01-01

    A 73-year old man was brought to our hospital because of acute onset of fever and consciousness disturbance. He had been hemodialyzed three times a week because of chronic renal failure since 13 years ago. Neurological examination revealed deteriorated consciousness and neck stiffness. A lumbar puncture yielded clouded fluid with a WBC 7,912/mm³ (polymorphonuclear cells 88%, mononuclear cells 12%), 786 mg/dl of protein and 4 mg/dl of glucose (blood glucose 118 mg/dl). Brain CT and MRI were unremarkable. He was treated with ceftriaxone and ampicillin. Streptococcus salivarius was isolated from the blood sample, but not from cerebrospinal fluid. The patient responded promptly to antibiotics therapy (ampicillin 3g/day, ceftriaxone 1g/day), and within several days he became lucid and afebrile. Isolated S. salivarius was sensitive for ampicillin and ceftriaxone. We diagnosed this case as S. salivarius bacteremia/meningoencephalitis. A gastrointestinal diagnostic workup revealed an asymptomatic gastric adenocarcinoma. S. salivarius is a common inhabitant of the oral mucosa that has been associated with infection in different sites. Meningeal infection by S. salivarius generally related to neoplasia of colon or iatrogenia, has been described on few occasions. This is the first report of S. salivarius bacteremia/meningoencephalitis associated with gastric neoplasm. Neurologist should be aware of the association of S. salivarius bacteremia/meningoencephalitis and gastrointestinal disease. PMID:22688117

  13. BRIEF HYPOXIA PRECEDING E. COLI BACTEREMIA DOWNREGULATES HEPATIC TNF-α PRODUCTION

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Hepatic TNF-α production following gram-negative bacteremia or hypovolemic shock predisposes to acute lung injury. However, TNF-α expression may be modified by the manner in which the hepatic O2 supply is reduced and equally important, its timing relative to bacteremia. Brief secondary hypoxic stress of buffer-perfused rat livers downregulates E. Coli (EC)-induced TNF-α expression whereas low-flow ischemia preceding EC increases subsequent TNF-α production owing to reactive O2 species (ROS). Here we determined whether 30 min of constant-flow hypoxia preceding 109 intraportal EC likewise increases antigenic and bioactive TNF-α protein concentrations during reoxygenation via production of ROS. Multiple groups (n=38) were studied over 180 minutes, circulation antigenic TNF-α decreased in H/R+EC vs. EC controls (1 939±640 vs. 12 407±2 476 μg/L at t=180 min; P<0.01, along with TNF-α bioactivity). TNF-α protein were not restored to control levels in ALLO+H/R+EC. Thus, EC-induced hepatic TNF-α production and export is strongly O2-dependent in intact liver regardless of the generation of ROS or the sequence of bacteremia and modest hypoxic stress.

  14. Evaluating Children with Otitis Media for Bacteremia or Urinary Tract Infection

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    Daniel Yawman

    2010-01-01

    Full Text Available Background. It is unclear if clinicians evaluate for concurrent bacteremia or UTI in young patients diagnosed with acute otitis media (AOM. Objectives. To describe how often, and under which circumstances, emergency providers investigate for bacteremia or UTI in 2–36 month olds with AOM. Methods. Cases of AOM were analyzed from the 2001–2004 National Hospital Ambulatory Medical Care Survey (NHAMCS-Emergency Department dataset. Results. AOM was diagnosed in 17% of the 10,847 recorded visits of 2–36 month olds. Of these visits, laboratory testing included: CBC: 7%, Blood culture: 4%, urinalysis or urine culture: 5%, and any of these tests: 9%. Rates of testing for 2–6 month olds with temperature ≥ 38.0 (CBC: 13%, blood culture: 9%, urinalysis or urine culture: 7%, any of the tests: 14% were not significantly different from testing of patients aged 6–12 months, or 12–36 months (all P>.1. Patients with temperature of ≥39.0 were more likely to have all tests, with the exception of urine investigation, than patients with temperature between 38.0 and 38.9. Conclusions. 17% of 2–36 month old patients seen in the emergency department are diagnosed with AOM. Investigating for bacteremia or UTI in these patients is not routine, even in febrile infants.

  15. Extensively drug-resistant bacteria are an independent predictive factor of mortality in 130 patients with spontaneous bacterial peritonitis or spontaneous bacteremia

    Science.gov (United States)

    Alexopoulou, Alexandra; Vasilieva, Larisa; Agiasotelli, Danai; Siranidi, Kyriaki; Pouriki, Sophia; Tsiriga, Athanasia; Toutouza, Marina; Dourakis, Spyridon P

    2016-01-01

    AIM: To evaluate the epidemiology and outcomes of culture-positive spontaneous bacterial peritonitis (SBP) and spontaneous bacteremia (SB) in decompensated cirrhosis. METHODS: We prospectively collected clinical, laboratory characteristics, type of administered antibiotic, susceptibility and resistance of bacteria to antibiotics in one hundred thirty cases (68.5% males) with positive ascitic fluid and/or blood cultures during the period from January 1, 2012 to May 30, 2014. All patients with SBP had polymorphonuclear cell count in ascitic fluid > 250/mm3. In patients with SB a thorough study did not reveal any other cause of bacteremia. The patients were followed-up for a 30-d period following diagnosis of the infection. The final outcome of the patients was recorded in the end of follow-up and comparison among 3 groups of patients according to the pattern of drug resistance was performed. RESULTS: Gram-positive-cocci (GPC) were found in half of the cases. The most prevalent organisms in a descending order were Escherichia coli (33), Enterococcus spp (30), Streptococcus spp (25), Klebsiella pneumonia (16), S. aureus (8), Pseudomanas aeruginosa (5), other Gram-negative-bacteria (GNB) (11) and anaerobes (2). Overall, 20.8% of isolates were multidrug-resistant (MDR) and 10% extensively drug-resistant (XDR). Health-care-associated (HCA) and/or nosocomial infections were present in 100% of MDR/XDR and in 65.5% of non-DR cases. Meropenem was the empirically prescribed antibiotic in HCA/nosocomial infections showing a drug-resistance rate of 30.7% while third generation cephalosporins of 43.8%. Meropenem was ineffective on both XDR bacteria and Enterococcus faecium (E. faecium). All but one XDR were susceptible to colistin while all GPC (including E. faecium) and the 86% of GNB to tigecycline. Overall 30-d mortality was 37.7% (69.2% for XDR and 34.2% for the rest of the patients) (log rank, P = 0.015). In multivariate analysis, factors adversely affecting outcome included

  16. A systematic review of animal models for Staphylococcus aureus osteomyelitis

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    W Reizner

    2014-03-01

    Full Text Available Staphylococcus aureus (S. aureus osteomyelitis is a significant complication for orthopaedic patients undergoing surgery, particularly with fracture fixation and arthroplasty. Given the difficulty in studying S. aureus infections in human subjects, animal models serve an integral role in exploring the pathogenesis of osteomyelitis, and aid in determining the efficacy of prophylactic and therapeutic treatments. Animal models should mimic the clinical scenarios seen in patients as closely as possible to permit the experimental results to be translated to the corresponding clinical care. To help understand existing animal models of S. aureus, we conducted a systematic search of PubMed and Ovid MEDLINE to identify in vivo animal experiments that have investigated the management of S. aureus osteomyelitis in the context of fractures and metallic implants. In this review, experimental studies are categorised by animal species and are further classified by the setting of the infection. Study methods are summarised and the relevant advantages and disadvantages of each species and model are discussed. While no ideal animal model exists, the understanding of a model’s strengths and limitations should assist clinicians and researchers to appropriately select an animal model to translate the conclusions to the clinical setting.

  17. Methicillin-resistant Staphylococcus aureus in central Iowa wildlife.

    Science.gov (United States)

    Wardyn, Shylo E; Kauffman, Lin K; Smith, Tara C

    2012-10-01

    Livestock and pets have been identified as carriers of Staphylococcus aureus; however, the role of wild animals as a reservoir of S. aureus strains has not yet been examined. We conducted a pilot study to determine the prevalence of methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) in 37 species of wild animals rehabilitated at a university clinic. Nasal, wing, wound, and cloacal swabs were collected. Of 114 animals, seven (6.1%) were MSSA-positive and three (2.6%) were MRSA-positive. The MRSA isolates were obtained from two eastern cottontail rabbits (Sylvilagus floridanus) and a Lesser Yellowlegs (Tringa flavipes), a migratory shorebird. Antibiotic resistance testing of the MRSA isolates revealed that two were additionally resistant to tetracycline and erythromycin, and the third isolate was also resistant to erythromycin, clindamycin, and levofloxacin. All three isolates were positive for the Panton-Valentine leukocidin (PVL) gene. Sequence typing of the staphylococcal protein A (spa) region revealed one MRSA isolate to be t002, whereas the other two MRSA isolates were found to be t008. Our results suggest that S. aureus, including MRSA, is being carried by wild animals, although at a low prevalence with the limited number of animals tested. Additional studies are needed to determine how this may impact human health. PMID:23060511

  18. Staphylococcus aureus biofilms: recent developments in biofilm dispersal.

    Science.gov (United States)

    Lister, Jessica L; Horswill, Alexander R

    2014-01-01

    Staphylococcus aureus is a major cause of nosocomial and community-acquired infections and represents a significant burden on the healthcare system. S. aureus attachment to medical implants and host tissue, and the establishment of a mature biofilm, play an important role in the persistence of chronic infections. The formation of a biofilm, and encasement of cells in a polymer-based matrix, decreases the susceptibility to antimicrobials and immune defenses, making these infections difficult to eradicate. During infection, dispersal of cells from the biofilm can result in spread to secondary sites and worsening of the infection. In this review, we discuss the current understanding of the pathways behind biofilm dispersal in S. aureus, with a focus on enzymatic and newly described broad-spectrum dispersal mechanisms. Additionally, we explore potential applications of dispersal in the treatment of biofilm-mediated infections.

  19. Kinase Inhibitors that Increase the Sensitivity of Methicillin Resistant Staphylococcus aureus to β-Lactam Antibiotics

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    Jay Vornhagen

    2015-10-01

    Full Text Available Staphylococcus aureus are Gram-positive bacteria that are the leading cause of recurrent infections in humans that include pneumonia, bacteremia, osteomyelitis, arthritis, endocarditis, and toxic shock syndrome. The emergence of methicillin resistant S. aureus strains (MRSA has imposed a significant concern in sustained measures of treatment against these infections. Recently, MRSA strains deficient in expression of a serine/threonine kinase (Stk1 or PknB were described to exhibit increased sensitivity to β-lactam antibiotics. In this study, we screened a library consisting of 280 drug-like, low-molecular-weight compounds with the ability to inhibit protein kinases for those that increased the sensitivity of wild-type MRSA to β-lactams and then evaluated their toxicity in mice. We report the identification of four kinase inhibitors, the sulfonamides ST085384, ST085404, ST085405, and ST085399 that increased sensitivity of WT MRSA to sub-lethal concentrations of β-lactams. Furthermore, these inhibitors lacked alerting structures commonly associated with toxic effects, and toxicity was not observed with ST085384 or ST085405 in vivo in a murine model. These results suggest that kinase inhibitors may be useful in therapeutic strategies against MRSA infections.

  20. Risk factors for multi-drug resistant Acinetobacter baumannii bacteremia in patients with colonization in the intensive care unit

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    Kim Se

    2010-07-01

    Full Text Available Abstract Background Epidemic outbreaks of multi-drug resistant (MDR Acinetobacter baumannii (AB in intensive care units (ICUs are increasing. The incidence of MDR AB bacteremia, which develops as a result of colonization, is increasing through widespread dissemination of the pathogen, and further colonization. We sought to determine risk factors for MDR AB bacteremia in patients colonized with MDR AB in the ICU. Methods We conducted a retrospective, observational study of 200 patients colonized with MDR AB in the ICU at Severance Hospital, South Korea during the outbreak period between January 2008 and December 2009. Results Of the 200 patients colonized with MDR AB, 108 developed MDR AB bacteremia, and 92 did not. APACHE II scores were higher in bacteremic than non-bacteremic patients at the time of ICU admission and colonization (24.0 vs. 21.6; P = 0.035, 22.9 vs. 16.8; P P = 0.923, but the duration of time at risk was shorter in bacteremic patients (12.1 vs. 6.0 days; P = 0.016. A recent invasive procedure was a significant risk factor for development of bacteremia (odds ratio = 3.85; 95% CI 1.45-10.24; P = 0.007. Multivariate analysis indicated infection and respiratory failure at the time of ICU admission, maintenance of mechanical ventilation, maintenance of endotracheal tube instead of switching to a tracheostomy, recent central venous catheter insertion, bacteremia caused by other microorganism after colonization by MDR AB, and prior antimicrobial therapy, were significant risk factors for MDR AB bacteremia. Conclusions Patients in the ICU, colonized with MDR AB, should be considered for minimizing invasive procedures and early removal of the invasive devices to prevent development of MDR AB bacteremia.

  1. Differing burden and epidemiology of non-Typhi Salmonella bacteremia in rural and urban Kenya, 2006-2009.

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    Collins Tabu

    Full Text Available BACKGROUND: The epidemiology of non-Typhi Salmonella (NTS bacteremia in Africa will likely evolve as potential co-factors, such as HIV, malaria, and urbanization, also change. METHODS: As part of population-based surveillance among 55,000 persons in malaria-endemic, rural and malaria-nonendemic, urban Kenya from 2006-2009, blood cultures were obtained from patients presenting to referral clinics with fever ≥38.0°C or severe acute respiratory infection. Incidence rates were adjusted based on persons with compatible illnesses, but whose blood was not cultured. RESULTS: NTS accounted for 60/155 (39% of blood culture isolates in the rural and 7/230 (3% in the urban sites. The adjusted incidence in the rural site was 568/100,000 person-years, and the urban site was 51/100,000 person-years. In both sites, the incidence was highest in children 85% of blood NTS isolates in both sites, but only 21% (urban and 64% (rural of stool NTS isolates. Overall, 76% of S. Typhimurium blood isolates were multi-drug resistant, most of which had an identical profile in Pulse Field Gel Electrophoresis. In the rural site, the incidence of NTS bacteremia increased during the study period, concomitant with rising malaria prevalence (monthly correlation of malaria positive blood smears and NTS bacteremia cases, Spearman's correlation, p = 0.018 for children, p = 0.16 adults. In the rural site, 80% of adults with NTS bacteremia were HIV-infected. Six of 7 deaths within 90 days of NTS bacteremia had HIV/AIDS as the primary cause of death assigned on verbal autopsy. CONCLUSIONS: NTS caused the majority of bacteremias in rural Kenya, but typhoid predominated in urban Kenya, which most likely reflects differences in malaria endemicity. Control measures for malaria, as well as HIV, will likely decrease the burden of NTS bacteremia in Africa.

  2. Clinical manifestations and outcome in Staphylococcus aureus endocarditis among injection drug users and nonaddicts: a prospective study of 74 patients

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    Ruotsalainen Eeva

    2006-09-01

    Full Text Available Abstract Background Endocarditis is a common complication in Staphylococcus aureus bacteremia (SAB. We compared risk factors, clinical manifestations, and outcome in a large, prospective cohort of patients with S. aureus endocarditis in injection drug users (IDUs and in nonaddicts. Methods Four hundred and thirty consecutive adult patients with SAB were prospectively followed up for 3 months. Definite or possible endocarditis by modified Duke criteria was found in 74 patients: 20 patients were IDUs and 54 nonaddicts. Results Endocarditis was more common in SAB among drug abusers (46% than in nonaddicts (14% (odds ratio [OR], 5.12; 95% confidence interval [CI], 2.65–9.91; P P P P = 0.03, and their SAB was more often community-acquired (95% vs 39%, P P P = 0.70. Arterial thromboembolic events and severe sepsis were also equally common in both groups. There was no difference in mortality between the groups at 7 days, but at 3 months it was lower among IDUs (10% compared with nonaddicts (39% (OR, 5.73; 95% CI, 1.20–27.25; P = 0.02. Conclusion S. aureus endocarditis in IDUs was associated with as high complication rates including extracardiac deep infections, thromboembolic events, or severe sepsis as in nonaddicts. Injection drug abuse in accordance with younger age and lack of underlying diseases were associated with lower mortality, but after adjusting by age and underlying diseases injection drug abuse was not significantly associated with mortality.

  3. Isorhamnetin Attenuates Staphylococcus aureus-Induced Lung Cell Injury by Inhibiting Alpha-Hemolysin Expression.

    Science.gov (United States)

    Jiang, Lanxiang; Li, Hongen; Wang, Laiying; Song, Zexin; Shi, Lei; Li, Wenhua; Deng, Xuming; Wang, Jianfeng

    2016-03-01

    Staphylococcus aureus, like other gram-positive pathogens, has evolved a large repertoire of virulence factors as a powerful weapon to subvert the host immune system, among which alpha-hemolysin (Hla), a secreted pore-forming cytotoxin, plays a preeminent role. We observed a concentration-dependent reduction in Hla production by S. aureus in the presence of sub-inhibitory concentrations of isorhamnetin, a flavonoid from the fruits of Hippophae rhamnoides L., which has little antibacterial activity. We further evaluate the effect of isorhamnetin on the transcription of the Hla-encoding gene hla and RNAIII, an effector molecule in the agr system. Isorhamnetin significantly down-regulated RNAIII expression and subsequently inhibited hla transcription. In a co-culture of S. aureus and lung cells, topical isorhamnetin treatment protected against S. aureus-induced cell injury. Isorhamnetin may represent a leading compound for the development of anti-virulence drugs against S. aureus infections. PMID:26643966

  4. NOD2 plays an important role in the inflammatory responses of macrophages to Staphylococcus aureus%NOD2在巨噬细胞对金黄葡萄球菌的炎性反应中的作用研究

    Institute of Scientific and Technical Information of China (English)

    谢旭华; 王丽丽; 龚凤云; 夏超; 宋莹; 宋建新

    2011-01-01

    Objective To investigate the effects of NOD2 on inflammatory responses of macrophages to Staphylococcus aureus. Methods Real-time RT-PCR detected NOD2 gene expression of macrophages infected by S. aureus. Synthesis of siRNA against NOD2 and interfere with macrophages, observed the effects of NOD2 gene silencing to phagocytosis of 5. aureus, cytokine secretion, activation of nuclear transcription factors, cell apoptosis of the macrophages infected by S. aureus using F.I .IS A, flow cytometry etc. Results S. aureus infection of macrophages can cause increased expression of intracellular NOD2. NOD2 gene silencing of macrophage lead to the decreased ability of phagocytosis with S. aureus, the lower levels of cytokines secretion, deficiencies of NF-κB activation. S. aureus can cause macrophage apoptosis, with the apoptosis rate increased with time. Conclusion The intracellular pattern recognition receptor NOD2 play a key role in pathogen recognition, signal transduction, activation of nuclear transcription factors in the process of macrophages infected by S. aureus.%目的 通过观察对比巨噬细胞NOD2基因沉默前后对金黄葡萄球菌感染的免疫应答,了解NOD2基因在金黄葡萄球菌感染巨噬细胞过程中所起的作用.方法 采用real-time RT-PCR的方法检测巨噬细胞NOD2基因在金黄葡萄球菌感染时的表达情况,合成针对NOD2的siRNA并干扰巨噬细胞.采用ELISA、流式细胞术等方法观察NOD2基因沉默对其在金黄葡萄球菌感染时的吞噬能力、细胞因子分泌水平、核转录因子(NF-κB)活化水平、细胞凋亡的影响.结果 金黄葡萄球菌感染巨噬细胞可引起细胞内NOD2表达增高.巨噬细胞NOD2基因沉默可导致其吞噬金黄葡萄球菌的能力降低,分泌细胞因子水平降低,NF-κB激活不足.金黄葡萄球菌可以引起巨噬细胞发生凋亡,凋亡率随时间延长而升高.结论 在金黄葡萄球菌感染巨噬细胞的过程中,位于细

  5. Staphylococcus aureus: resistance pattern and risk factors

    Directory of Open Access Journals (Sweden)

    Mohammad Naghavi-Behzad

    2015-03-01

    Full Text Available Introduction: Methicillin resistant Staphylococcus aureus (MRSA has emerged as a nosocomial pathogen of major worldwide importance and is an increasingly frequent cause of community-acquired infections. In this study, different risk factors and MRSA resistance pattern were investigated. Methods: In a 24 months period, all of the patients who were confined to bed in the surgery ward were included in the study. Then they were assessed to find out as if they had MRSA infection when hospitalized and once when they were discharged. Almost 48 h after admission, when patients were discharged, social and medical histories were acquired. Acquired samples were examined. Results: During the present study of 475 patients, 108 patients (22.8% had S. aureus. About frequency of antibiotic resistance among collected S. aureus colonies, erythromycin resistance, was the most frequent antibiotic resistance, also resistance to vancomycin was 0.4% that was the least. Only hospitalization duration had statistically significant correlation with antibiotic resistance, also resistance to erythromycin had statistically significant relation with history of surgery and alcohol consumption. Of all 34 MRSA species, 22 (64.7% samples were resistant to erythromycin, 17 (50.0% resistant to cefoxitin, 5 (14.7% resistant to mupirocin, 1 (2.9% resistant to vancomycin and 1 (2.9% resistant to linezolid. Conclusion: The results of the current study show that among hospitalized patients, there is resistance against methicillin. Since based on results of the study there is resistance against oxacillin and erythromycin in most cases, administering appropriate antibiotics have an important role in minimizing the resistance burden among bacterial species.

  6. Host-adaptive evolution of Staphylococcus aureus

    OpenAIRE

    Lowder, Bethan Victoria

    2011-01-01

    Staphylococcus aureus is a notorious human pathogen associated with severe nosocomial and community-acquired infections. In addition, S. aureus is a major cause of animal diseases including skeletal infections of poultry and bovine and ovine mastitis, which are a large economic burden on the broiler chicken and dairy farming industries. The population structure of S. aureus associated with humans has been well studied. However, despite the prevalence of S. aureus infections in ...

  7. Third generation cephalosporin resistant Enterobacteriaceae and multidrug resistant gram-negative bacteria causing bacteremia in febrile neutropenia adult cancer patients in Lebanon, broad spectrum antibiotics use as a major risk factor, and correlation with poor prognosis

    Directory of Open Access Journals (Sweden)

    Rima eMoghnieh

    2015-02-01

    Full Text Available Bacteremia remains a major cause of life-threatening complications in patients receiving anticancer chemotherapy. The spectrum and susceptibility profiles of causative microorganisms differ with time and place. Data from Lebanon are scarce. We aim at evaluating the epidemiology of bacteremia in cancer patients in a university hospital in Lebanon, emphasizing antibiotic resistance and risk factors of multi-drug resistant organism (MDRO-associated bacteremia.This is a retrospective study of 75 episodes of bacteremia occurring in febrile neutropenic patients admitted to the hematology-oncology unit at Makassed General Hospital, Lebanon, from October 2009-January 2012.It corresponds to epidemiological data on bacteremia episodes in febrile neutropenic cancer patients including antimicrobial resistance and identification of risk factors associated with third generation cephalosporin resistance (3GCR and MDRO-associated bacteremia. Out of 75 bacteremias, 42.7% were gram-positive (GP, and 57.3% were gram-negative (GN. GP bacteremias were mostly due to methicillin-resistant coagulase negative staphylococci (28% of total bacteremias and 66% of GP bacteremias. Among the GN bacteremias, Escherichia coli (22.7% of total, 39.5% of GN organisms and Klebsiellapneumoniae(13.3% of total, 23.3% of GN organisms were the most important causative agents. GN bacteremia due to 3GC sensitive (3GCS bacteria represented 28% of total bacteremias, while 29% were due to 3GCR bacteria and 9% were due to carbapenem-resistant organisms. There was a significant correlation between bacteremia with MDRO and subsequent intubation, sepsis and mortality. Among potential risk factors, only broad spectrum antibiotic intake >4 days before bacteremia was found to be statistically significant for acquisition of 3GCR bacteria. Using carbapenems or piperacillin/ tazobactam>4 days before bacteremia was significantly associated with the emergence of MDRO (p value<0.05.

  8. [Protein toxins of Staphylococcus aureus].

    Science.gov (United States)

    Shamsutdinov, A F; Tiurin, Iu A

    2014-01-01

    Main scientific-research studies regarding protein bacterial toxins of the most widespread bacteria that belong to Staphylococcus spp. genus and in particular the most pathogenic species for humans--Staphylococcus aureus, are analyzed. Structural and biological properties of protein toxins that have received the name of staphylococcus pyrogenic toxins (PTSAg) are presented. Data regarding genetic regulation of secretion and synthesis of these toxins and 3 main regulatory genetic systems (agr--accessory gene regulator, xpr--extracellular protein regulator, sar--staphylococcal accessory regulator) that coordinate synthesis of the most important protein toxins and enzymes for virulence of S. aureus, are presented.

  9. Studies of the in Vitro Antibacterial Activities of Several Polyphenols against Clinical Isolates of Methicillin-Resistant Staphylococcus aureus

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    Yanli Su

    2014-08-01

    Full Text Available In this study, we report the antibacterial activities of six polyphenols (i.e., luteolin, quercetin, scutellarin, apigenin, chlorogenic acid, and resveratrol against 29 clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA, and in vitro antibacterial activities of two-drug combinations. All of the MRSA strains evaluated were clinical isolates from patients with MRSA bacteremia. The antibacterial activities were determined by agar dilution method, and the two-drug antibacterial activities were determined by the checkerboard agar dilution method. It was found that luteolin, quercetin and resveratrol show obvious antibacterial activities against MRSA, and the results of two-drug antibacterial activity show either synergy or additivity, without evidences of antagonistic effects.

  10. The cefazolin inoculum effect in methicillin-susceptible Staphylococcus aureus blood isolates: their association with dysfunctional accessory gene regulator (agr).

    Science.gov (United States)

    Wi, Yu Mi; Park, Young Kyoung; Moon, Chisook; Ryu, Seong Yeol; Lee, Hyuck; Ki, Hyun Kyun; Cheong, Hae Suk; Son, Jun Seong; Lee, Jin Seo; Kwon, Ki Tae; Kim, June Myong; Ha, Young Eun; Kang, Cheol In; Ko, Kwan Soo; Chung, Doo Ryeon; Peck, Kyong Ran; Song, Jae-Hoon

    2015-11-01

    We evaluated the clinical significance of the cefazolin inoculum effect (CIE) in methicillin-susceptible Staphylococcus aureus (MSSA) isolates. In total, 146 isolates were recovered from patients with MSSA bacteremia at 9 hospitals in Korea. The CIE was observed in 16 MSSA isolates, and while type A was the only detected β-lactamase in MSSA isolates exhibiting the CIE, no strains expressing type B, C, or D β-lactamases exhibited this effect. The CIE was only observed in agr group III and I isolates and was significantly more common in isolates with agr dysfunction than in those with functional agr (P<0.001). Even among isolates producing type A β-lactamase, the CIE was also prevalent in isolates with dysfunctional agr than in isolates with functional agr (P=0.025). This study demonstrates an association between the CIE of MSSA isolates and agr dysfunction, in addition to those between the CIE and type A β-lactamase.

  11. Treatment of methicillin-resistant Staphylococcus aureus: vancomycin and beyond.

    Science.gov (United States)

    Holmes, Natasha E; Tong, Steven Y C; Davis, Joshua S; van Hal, Sebastiaan J

    2015-02-01

    There has been a welcome increase in the number of agents available for the treatment of methicillin-resistant Staphylococcus aureus (MRSA). Vancomycin remains an acceptable treatment option, with moves toward individualized dosing to a pharmacokinetic/pharmacodynamic (PK/PD) target. Numerous practicalities, however, would need to be resolved before implementation. Lipoglycopeptides as a class show excellent in vitro potency. Their long half-lives and complex PKs may preclude these agents being used in critically ill patients. Anti-MRSA cephalosporins provide great promise in the treatment of MRSA. These agents, despite broad-spectrum activity, should be reserved for patients with MRSA infections as it is likely that usage will be associated with increased rates of resistance. Daptomycin is currently the only antibiotic to have shown noninferiority to vancomycin in the treatment of MRSA bacteremia. The results of an open-labeled trial to address the superiority of daptomycin compared with vancomycin in reduced vancomycin susceptibility infections are eagerly anticipated. No drug to date has shown superiority to vancomycin in the treatment of MRSA infections with the possible exception of linezolid in hospital-acquired pneumonia (HAP), making linezolid an important option in the treatment of MRSA-proven HAP. Whether these strengths and features are agent or class specific are unclear but will likely be answered with the marketing of tedizolid. There are insufficient data to recommend either quinupristin/dalfopristin or tigecycline, as first line in the treatment of severe MRSA infections. These agents however remain options in patients with no other alternatives. PMID:25643268

  12. Prevention of Healthcare Associated Staphylococcus aureus Infections

    NARCIS (Netherlands)

    L.G.M. Bode (Lonneke)

    2014-01-01

    markdownabstract__Abstract__ S. aureus colonizes the skin and mucosae of a proportion of the human population. Carriers of S. aureus are at increased risk of developing infections with this pathogen. The aim of this thesis was to add to the prevention of healthcare associated S. aureus infections.

  13. Etiological Misidentification by Routine Biochemical Tests of Bacteremia Caused by Gordonia terrae Infection in the Course of an Episode of Acute Cholecystitis

    Science.gov (United States)

    Gil-Sande, E.; Brun-Otero, M.; Campo-Cerecedo, F.; Esteban, E.; Aguilar, L.; García-de-Lomas, J.

    2006-01-01

    Gordonia terrae has been reported to be a rare cause of bacteremia. We report the first case of bacteremia associated with acute cholecystitis. Commercial biochemical testing was not able to identify the strain at the genus level, classifying it instead as Rhodococcus sp. Definitive identification was obtained by sequencing of the 16S rRNA gene. PMID:16825404

  14. Where does a Staphylococcus aureus vaccine stand?

    Science.gov (United States)

    Fowler, V G; Proctor, R A

    2014-05-01

    In this review, we examine the current status of Staphylococcus aureus vaccine development and the prospects for future vaccines. Examination of the clinical trials to date show that murine models have not predicted success in humans for active or passive immunization. A key factor in the failure to develop a vaccine to prevent S. aureus infections comes from our relatively limited knowledge of human protective immunity. More recent reports on the elements of the human immune response to staphylococci are analysed. In addition, there is some controversy concerning the role of antibodies for protecting humans, and these data are reviewed. From a review of the current state of understanding of staphylococcal immunity, a working model is proposed. Some new work has provided some initial candidate biomarker(s) to predict outcomes of invasive infections and to predict the efficacy of antibiotic therapy in humans. We conclude by looking to the future through the perspective of lessons gleaned from the clinical vaccine trials. PMID:24476315

  15. Stress Responses in Staphylococcus aureus

    DEFF Research Database (Denmark)

    Frees, Dorte; Ingmer, Hanne

    2016-01-01

    Staphylococcus aures are prominent members of the normal flora of humans and animals, but are also a major cause of mild and severe infections. To persist and disseminate in the human host, and to survive in environmental settings, such as hospitals, S. aureus have developed a plethora of cellular...

  16. Clostridium difficile bacteremia and meningitis as a complication of prolonged cephalosporin therapy in a case of staphylococcal pyogenic arthritis

    Institute of Scientific and Technical Information of China (English)

    Abhrajit Ganguly; Saibal Das; Jayanta Kumar Dey; Somnath Mondal

    2012-01-01

    With increasing incidence of Clostridium difficile (C. difficile) associated diarrhea and pseudomembranous colitis, several extra-intestinal manifestations of the organism have been unmasked which include-bacteremia, brain abscess, pericarditis etc. We report a rare and interesting case of C. difficile bacteremia and subsequent meningitis in a 10 year old child. The child was immune competent, which further raises the question about the virulent possibilities of the organism and its implications in the near future. The condition resulted from a prolonged treatment with intravenous (I.V.) cefotaxime for staphylococcal pyogenic arthritis. The child recovered from the septic arthritis but on the 7th day post-admission developed features of bacteremia. The child was later treated with intravenous metronidazole and vancomycin and he was discharged on the 21st day post-admission. No recurrence of symptoms was noted.

  17. Clostridium difficile bacteremia and meningitis as a complication of prolonged cephalosporin therapy in a case of staphylococcal pyogenic arthritis

    Directory of Open Access Journals (Sweden)

    Abhrajit Ganguly

    2012-01-01

    Full Text Available With increasing incidence of Clostridium difficile (C. difficile associated diarrhea and pseudomembranous colitis, several extra-intestinal manifestations of the organism have been unmasked which include-bacteremia, brain abscess, pericarditis etc. We report a rare and interesting case of C. difficile bacteremia and subsequent meningitis in a 10 year old child. The child was immune competent, which further raises the question about the virulent possibilities of the organism and its implications in the near future. The condition resulted from a prolonged treatment with intravenous (I.V. cefotaxime for staphylococcal pyogenic arthritis. The child recovered from the septic arthritis but on the 7th day post-admission developed features of bacteremia. The child was later treated with intravenous metronidazole and vancomycin and he was discharged on the 21st day post-admission. No recurrence of symptoms was noted.

  18. Streptococcus salivarius bacteremia and spontaneous bacterial peritonitis in liver transplantation candidates.

    Science.gov (United States)

    Gautam, Manjushree; Chopra, Kapil B; Douglas, David D; Stewart, Rebecca A; Kusne, Shimon

    2007-11-01

    Bacterial infections are a serious complication of end-stage liver disease (ESLD) that occurs in 20% to 60% of patients. We retrospectively reviewed medical records of patients with ESLD who were identified by our microbiology laboratory as having Streptococcus salivarius bacteremia. Of 592 patients listed for transplantation between January 1998 and January 2006, 9 (1.5%) had 10 episodes of S salivarius bacteremia. Of 2 patients already receiving quinolone prophylaxis for spontaneous bacterial peritonitis (SBP), 1 later presented with a second episode. The male-to-female ratio was 1:1.2. Medians for age, Model for End-Stage Liver Disease score, and Child-Turcotte-Pugh score were 50 years, 17, and 10, respectively. Presenting symptoms and signs in 10 episodes of infection were ascites (in 8 episodes), elevated temperature (6), abdominal pain (5), and encephalopathy (4). Median laboratory values included: white blood cell count, 15.1 x 10(9)/L; creatinine, 0.9 mg/dL; albumin, 3.1 gm/dL; aspartate aminotransferase, 64 U/L; alanine aminotransferase, 52.5 U/L; ammonia, 67 mug/dL; and prothrombin time, 17.3 seconds. Ascitic fluid in patients with peritonitis showed a median white blood cell count of 466 cells/mm(3) (range, 250-12,822 cells/mm(3)), with 66% polymorphs, protein of 0.9 gm/dL, and albumin of 0.4 gm/dL. S salivarius may cause primary bacteremia and SBP in liver transplantation candidates despite quinolone prophylaxis. PMID:17969206

  19. Identifying Patients with Bacteremia in Community-Hospital Emergency Rooms: A Retrospective Cohort Study.

    Directory of Open Access Journals (Sweden)

    Taro Takeshima

    Full Text Available (1 To develop a clinical prediction rule to identify patients with bacteremia, using only information that is readily available in the emergency room (ER of community hospitals, and (2 to test the validity of that rule with a separate, independent set of data.Multicenter retrospective cohort study.To derive the clinical prediction rule we used data from 3 community hospitals in Japan (derivation. We tested the rule using data from one other community hospital (validation, which was not among the three "derivation" hospitals.Adults (age ≥ 16 years old who had undergone blood-culture testing while in the ER between April 2011 and March 2012. For the derivation data, n = 1515 (randomly sampled from 7026 patients, and for the validation data n = 467 (from 823 patients.We analyzed 28 candidate predictors of bacteremia, including demographic data, signs and symptoms, comorbid conditions, and basic laboratory data. Chi-square tests and multiple logistic regression were used to derive an integer risk score (the "ID-BactER" score. Sensitivity, specificity, likelihood ratios, and the area under the receiver operating characteristic curve (i.e., the AUC were computed.There were 241 cases of bacteremia in the derivation data. Eleven candidate predictors were used in the ID-BactER score: age, chills, vomiting, mental status, temperature, systolic blood pressure, abdominal sign, white blood-cell count, platelets, blood urea nitrogen, and C-reactive protein. The AUCs was 0.80 (derivation and 0.74 (validation. For ID-BactER scores ≥ 2, the sensitivities for derivation and validation data were 98% and 97%, and specificities were 20% and 14%, respectively.The ID-BactER score can be computed from information that is readily available in the ERs of community hospitals. Future studies should focus on developing a score with a higher specificity while maintaining the desired sensitivity.

  20. Clostridium perfringens bacteremia caused by choledocholithiasis in the absence of gallbladder stones

    Institute of Scientific and Technical Information of China (English)

    Antwan Atia; Tejas Raiyani; Pranav Patel; Robert Patton; Mark Young

    2012-01-01

    A 67-years-old male presented with periumbilical abdominal pain,fever and jaundice.His anaerobic blood culture was positive for clostridium perfringens.Computed tomogram scan of the abdomen and abdominal ultrasound showed normal gallbladder and common bile duct (CBD).Subsequently magnetic resonance cholangiopancreaticogram showed choledocholithiasis.Endoscopic retrograde cholangiopancreaticogramwith sphincterotomy and CBD stone extraction was performed.The patient progressively improved with antibiotic therapy Choledocholithiasis should be considered as a source of clostridium perfringens bacteremia especially in the setting of elevated liver enzymes with cholestatic pattern.

  1. Staphylococcus pettenkoferi Bacteremia: A Case Report and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Abdulaziz Ahmed Hashi

    2015-01-01

    Full Text Available Staphylococcus pettenkoferi is a relatively recently described coagulase-negative staphylococci species first described in 2002. Since then, nine additional cases of infection caused by this species have been reported in various countries around the world, including Germany, Belgium, France, South Korea, Italy, Brazil and Mexico. The present report describes a case of S pettenkoferi peripheral line-associated bacteremia. To our knowledge, the present report is the first description of human infection caused by S pettenkoferi in Canada. The present report also provides an overview of the laboratory detection of uncommon coagulase-negative staphylococci.

  2. Intravenous Drug Abuse by Patients Inside the Hospital: A Cause for Sustained Bacteremia.

    Science.gov (United States)

    Goel, Noopur; Munshi, Lubna Bashir; Thyagarajan, Braghadheeswar

    2016-01-01

    Patients with history of intravenous drug abuse are noted to be at risk of several infections including HIV, endocarditis, and other opportunistic infections. We report the case of a patient with sustained Bacillus cereus bacteremia despite use of multiple antibiotic regimens during his inpatient stay. Our case highlights the importance of high suspicion for active drug use inside the hospital in such patients. This is important in order to minimize unnecessary diagnostic workup and provide adequate treatment and safe hospital stay for these patients. PMID:27433362

  3. Rapid diagnosis of bacteremia in adults using acridine orange stained buffy coat smears

    OpenAIRE

    Miller, Mark; Mendelson, Jack

    1990-01-01

    The use of acridine orange stained buffy coat smears was assessed as a rapid screening test for bacteremia in adults. A total of 356 consecutive blood cultures were submitted with simultaneous anticoagulated blood samples, from which a buffy coat smear was prepared and stained with acridine orange (100 mg/L; pH 3.0). Forty-one of 356 blood samples (12%) yielded organisms in the blood culture system. Compared to blood culture, the overall sensitivity of acridine orange stained buffy coat smear...

  4. Extended spectrum β-lactamase producing Shigella flexneri serotype-2 causing bacteremia in a patient with uncontrolled diabetes mellitus.

    Science.gov (United States)

    Ninan, Marilyn M; George, Tarun K; Balaji, V; Ramya, I

    2016-01-01

    We report a case of Shigella flexneri serotype-2 causing bacteremia in an elderly gentleman with uncontrolled diabetes mellitus, who had no other apparent risk factors. Antibiotic susceptibility testing revealed that the organism was a multidrug resistant extended spectrum beta-lactamase producing straian, which was confirmed by molecular characterization. This rare case alerts both the clinician and microbiologist to a previously unaddressed risk factor of Shigella spp. causing bacteremia, as well as emerging resistant strains that are on the rise in immunocompromised patients. PMID:27510696

  5. Phenotypes and Virulence among Staphylococcus aureus USA100, USA200, USA300, USA400, and USA600 Clonal Lineages.

    Science.gov (United States)

    King, Jessica M; Kulhankova, Katarina; Stach, Christopher S; Vu, Bao G; Salgado-Pabón, Wilmara

    2016-01-01

    Staphylococcus aureus diseases affect ~500,000 individuals per year in the United States. Worldwide, the USA100, USA200, USA400, and USA600 lineages cause many of the life-threatening S. aureus infections, such as bacteremia, infective endocarditis, pneumonia, toxic shock syndrome, and surgical site infections. However, the virulence mechanisms associated with these clonal lineages, in particular the USA100 and USA600 isolates, have been severely understudied. We investigated the virulence of these strains, in addition to strains in the USA200, USA300, and USA400 types, in well-established in vitro assays and in vivo in the rabbit model of infective endocarditis and sepsis. We show in the infective endocarditis and sepsis model that strains in the USA100 and USA600 lineages cause high lethality and are proficient in causing native valve infective endocarditis. Strains with high cytolytic activity or producing toxic shock syndrome toxin 1 (TSST-1) or staphylococcal enterotoxin C (SEC) caused lethal sepsis, even with low cytolytic activity. Strains in the USA100, USA200, USA400, and USA600 lineages consistently contained genes that encode for the enterotoxin gene cluster proteins, SEC, or TSST-1 and were proficient at causing infective endocarditis, while the USA300 strains lacked these toxins and were deficient in promoting vegetation growth. The USA100, USA200, and USA400 strains in our collection formed strong biofilms in vitro, whereas the USA200 and USA600 strains exhibited increased blood survival. Hence, infective endocarditis and lethal sepsis are multifactorial and not intrinsic to any one individual clonal group, further highlighting the importance of expanding our knowledge of S. aureus pathogenesis to clonal lineages causative of invasive disease. IMPORTANCE S. aureus is the leading cause of infective endocarditis in the developed world, affecting ~40,000 individuals each year in the United States, and the second leading cause of bacteremia (D. R

  6. Staphylococcus aureus redirects central metabolism to increase iron availability.

    Directory of Open Access Journals (Sweden)

    David B Friedman

    2006-08-01

    Full Text Available Staphylococcus aureus pathogenesis is significantly influenced by the iron status of the host. However, the regulatory impact of host iron sources on S. aureus gene expression remains unknown. In this study, we combine multivariable difference gel electrophoresis and mass spectrometry with multivariate statistical analyses to systematically cluster cellular protein response across distinct iron-exposure conditions. Quadruplicate samples were simultaneously analyzed for alterations in protein abundance and/or post-translational modification state in response to environmental (iron chelation, hemin treatment or genetic (Deltafur alterations in bacterial iron exposure. We identified 120 proteins representing several coordinated biochemical pathways that are affected by changes in iron-exposure status. Highlighted in these experiments is the identification of the heme-regulated transport system (HrtAB, a novel transport system which plays a critical role in staphylococcal heme metabolism. Further, we show that regulated overproduction of acidic end-products brought on by iron starvation decreases local pH resulting in the release of iron from the host iron-sequestering protein transferrin. These findings reveal novel strategies used by S. aureus to acquire scarce nutrients in the hostile host environment and begin to define the iron and heme-dependent regulons of S. aureus.

  7. Exaggerated Acute Lung Injury and Impaired Antibacterial Defenses During Staphylococcus aureus Infection in Rats with the Metabolic Syndrome.

    Directory of Open Access Journals (Sweden)

    Xiaomei Feng

    Full Text Available Rats with Metabolic Syndrome (MetaS have a dysregulated immune response to the aseptic trauma of surgery. We hypothesized that rats with MetaS would have dysregulated inflammation, increased lung injury, and less effective antibacterial defenses during Staphylococcus (S. aureus sepsis as compared to rats without MetaS. Low capacity runner (LCR; a model of MetaS and high capacity runner (HCR rats were challenged intravenously with S. aureus bacteria. After 48 h, inflammatory mediators and bacteria were quantified in the blood, bronchoalveolar lavage fluid (BALF, and lung homogenates. Lungs were analyzed histologically. BALF protein and lung wet-dry ratios were quantified to assess for vascular leak. Endpoints were compared in infected LCR vs HCR rats. LCR rats had higher blood and lung S. aureus counts, as well as higher levels of IL-6 in plasma, lungs and BALF, MIP-2 in plasma and lung, and IL-17A in lungs. Conversely, LCR rats had lower levels of IL-10 in plasma and lungs. Although lactate levels, and liver and renal function tests were similar between groups, LCR rats had higher BALF protein and lung wet-dry ratios, and more pronounced acute lung injury histologically. During S. aureus bacteremia, as compared with HCR rats, LCR (MetaS rats have heightened pro-inflammatory responses, accompanied by increased acute lung injury and vascular leak. Notably, despite an augmented pro-inflammatory phenotype, LCR rats have higher bacterial levels in their blood and lungs. The MetaS state may exacerbate lung injury and vascular leak by attenuating the inflammation-resolving response, and by weakening antimicrobial defenses.

  8. Exaggerated Acute Lung Injury and Impaired Antibacterial Defenses During Staphylococcus aureus Infection in Rats with the Metabolic Syndrome.

    Science.gov (United States)

    Feng, Xiaomei; Maze, Mervyn; Koch, Lauren G; Britton, Steven L; Hellman, Judith

    2015-01-01

    Rats with Metabolic Syndrome (MetaS) have a dysregulated immune response to the aseptic trauma of surgery. We hypothesized that rats with MetaS would have dysregulated inflammation, increased lung injury, and less effective antibacterial defenses during Staphylococcus (S.) aureus sepsis as compared to rats without MetaS. Low capacity runner (LCR; a model of MetaS) and high capacity runner (HCR) rats were challenged intravenously with S. aureus bacteria. After 48 h, inflammatory mediators and bacteria were quantified in the blood, bronchoalveolar lavage fluid (BALF), and lung homogenates. Lungs were analyzed histologically. BALF protein and lung wet-dry ratios were quantified to assess for vascular leak. Endpoints were compared in infected LCR vs HCR rats. LCR rats had higher blood and lung S. aureus counts, as well as higher levels of IL-6 in plasma, lungs and BALF, MIP-2 in plasma and lung, and IL-17A in lungs. Conversely, LCR rats had lower levels of IL-10 in plasma and lungs. Although lactate levels, and liver and renal function tests were similar between groups, LCR rats had higher BALF protein and lung wet-dry ratios, and more pronounced acute lung injury histologically. During S. aureus bacteremia, as compared with HCR rats, LCR (MetaS) rats have heightened pro-inflammatory responses, accompanied by increased acute lung injury and vascular leak. Notably, despite an augmented pro-inflammatory phenotype, LCR rats have higher bacterial levels in their blood and lungs. The MetaS state may exacerbate lung injury and vascular leak by attenuating the inflammation-resolving response, and by weakening antimicrobial defenses.

  9. Prevalence of methicillin resistance and virulence determinants of Staphylococcus aureus in diabetic foot ulcers

    Directory of Open Access Journals (Sweden)

    Sumeet Sandhu

    2014-12-01

    Conclusions: DNA-based detection and characterization of bacteria in DFUs are rapid and efficient and can assist in accurate, targeted antibiotic therapy of DFU infections. The majority of S. aureus detected in this study were highly virulent and also resistant to methicillin. Further studies are required to understand the role of S. aureus in DFU trajectory. [Int J Basic Clin Pharmacol 2014; 3(6.000: 978-982

  10. Risk and Prognosis of Bacteremia and Fungemia among Peritoneal Dialysis Patients

    DEFF Research Database (Denmark)

    Dalgaard, Lars S; Nørgaard, Mette; Povlsen, Johan V;

    2016-01-01

    ♦ Background: The incidence of bacteremia and fungemia (BAF) is largely unknown in end-stage renal disease (ESRD) patients initiating peritoneal dialysis (PD). ♦ Objective: The main objective was to estimate and compare incidence rates of first episodes of BAF in incident PD patients and a compar......♦ Background: The incidence of bacteremia and fungemia (BAF) is largely unknown in end-stage renal disease (ESRD) patients initiating peritoneal dialysis (PD). ♦ Objective: The main objective was to estimate and compare incidence rates of first episodes of BAF in incident PD patients...... and a comparison cohort. A secondary objective was to compare causative agents and 30-day post-BAF mortality between PD patients and the comparison cohort. ♦ Methods: Design: Observational cohort study. SETTING: Central and North Denmark regions. PARTICIPANTS: patients who initiated PD during 1995 - 2010. For each...... and population controls. Incidence-rate ratios (IRRs) were calculated to compare these rates. Thirty-day mortality was estimated by Kaplan-Meier analysis. ♦ Results: Among 1,024 PD patients and 10,215 population controls, we identified 75 and 282 episodes of BAF, respectively. Incidence rates of BAF were 4.7 (95...

  11. Streptococcus intermedius Bacteremia and Liver Abscess following a Routine Dental Cleaning

    Directory of Open Access Journals (Sweden)

    Lachara V. Livingston

    2014-01-01

    Full Text Available Streptococcus intermedius is a member of the Streptococcus anginosus group of bacteria. This group is part of the normal flora of the oropharynx, genitourinary, and gastrointestinal tracts; however, they have been known to cause a variety of purulent infections including meningitis, endocarditis, and abscesses, even in immunocompetent hosts. In particular, S. intermedius has been associated with the development of liver and brain abscesses. There have been several case reports of S. intermedius liver abscesses with active periodontal infection. To our knowledge, however, there has not been a case following a routine dental procedure. In fact, the development of liver abscesses secondary to dental procedures is very rare in general, and there are only a few case reports in the literature describing this in relation to any pathogen. We present a rare case of S. intermedius bacteremia and liver abscess following a dental cleaning. This case serves to further emphasize that even routine dental procedures can place a patient at risk of the development of bacteremia and liver abscesses. For this reason, the clinician must be sure to perform a detailed history and careful examination. Timely diagnosis of pyogenic liver abscesses is vital, as they are typically fatal if left untreated.

  12. Streptococcus intermedius Bacteremia and Liver Abscess following a Routine Dental Cleaning.

    Science.gov (United States)

    Livingston, Lachara V; Perez-Colon, Elimarys

    2014-01-01

    Streptococcus intermedius is a member of the Streptococcus anginosus group of bacteria. This group is part of the normal flora of the oropharynx, genitourinary, and gastrointestinal tracts; however, they have been known to cause a variety of purulent infections including meningitis, endocarditis, and abscesses, even in immunocompetent hosts. In particular, S. intermedius has been associated with the development of liver and brain abscesses. There have been several case reports of S. intermedius liver abscesses with active periodontal infection. To our knowledge, however, there has not been a case following a routine dental procedure. In fact, the development of liver abscesses secondary to dental procedures is very rare in general, and there are only a few case reports in the literature describing this in relation to any pathogen. We present a rare case of S. intermedius bacteremia and liver abscess following a dental cleaning. This case serves to further emphasize that even routine dental procedures can place a patient at risk of the development of bacteremia and liver abscesses. For this reason, the clinician must be sure to perform a detailed history and careful examination. Timely diagnosis of pyogenic liver abscesses is vital, as they are typically fatal if left untreated.

  13. Bacteremia due to Achromobacter xylosoxidans in neonates: clinical features and outcome

    Directory of Open Access Journals (Sweden)

    Ozden Turel

    2013-08-01

    Full Text Available OBJECTIVE: We report an outbreak of Achromobacter xylosoxidans at a neonatal intensive care unit. We aimed to present clinical, laboratory and treatment data of the patients. Materials and METHODS: All consecutive episodes of bacteremia due to A. xylosoxidans at our neonatal intensive care unit, beginning with the index case detected at November 2009 until cessation of the outbreak in April 2010, were evaluated retrospectively. RESULTS: Thirty-four episodes of bacteremia occurred in 22 neonates during a 6-month period. Among the affected, 90% were preterm newborns with gestational age of 32 weeks or less and 60% had birth weight of 1000 g or less. Endotracheal intubation, intravenous catheter use, total parenteral nutrition and prolonged antibiotic therapy were the predisposing conditions. Presenting features were abdominal distention, thrombocytopenia and neutropenia. The mortality rate was 13.6% and the majority of isolates were susceptible to piperacillin-tazobactam, carbapenems and trimethoprim-sulfametoxazole, and resistant to gentamycin. More than half were breakthrough infections. Despite intensive efforts to control the outbreak by standard methods of hand hygiene, patient screening and isolation, containment could be achieved only after the neonatal intensive care unit was relocated. The investigation was not able to single out the source of the outbreak. CONCLUSION: A. xylosoxidans has the potential to cause serious infections in premature babies. More studies are needed to determine the importance of different sources of infection in hospital units.

  14. Staphylococcus aureus produces membrane-derived vesicles that induce host cell death.

    Directory of Open Access Journals (Sweden)

    Mamata Gurung

    Full Text Available Gram-negative bacteria produce outer membrane vesicles that play a role in the delivery of virulence factors to host cells. However, little is known about the membrane-derived vesicles (MVs produced by gram-positive bacteria. The present study examined the production of MVs from Staphylococcus aureus and investigated the delivery of MVs to host cells and subsequent cytotoxicity. Four S. aureus strains tested, two type strains and two clinical isolates, produced spherical nanovesicles during in vitro culture. MVs were also produced during in vivo infection of a clinical S. aureus isolate in a mouse pneumonia model. Proteomic analysis showed that 143 different proteins were identified in the S. aureus-derived MVs. S. aureus MVs were interacted with the plasma membrane of host cells via a cholesterol-rich membrane microdomain and then delivered their component protein A to host cells within 30 min. Intact S. aureus MVs induced apoptosis of HEp-2 cells in a dose-dependent manner, whereas lysed MVs neither delivered their component into the cytosol of host cells nor induced cytotoxicity. In conclusion, this study is the first report that S. aureus MVs are an important vehicle for delivery of bacterial effector molecules to host cells.

  15. High-resolution subtyping of Staphylococcus aureus strains by means of Fourier-transform infrared spectroscopy.

    Science.gov (United States)

    Johler, Sophia; Stephan, Roger; Althaus, Denise; Ehling-Schulz, Monika; Grunert, Tom

    2016-05-01

    Staphylococcus aureus causes a variety of serious illnesses in humans and animals. Subtyping of S. aureus isolates plays a crucial role in epidemiological investigations. Metabolic fingerprinting by Fourier-transform infrared (FTIR) spectroscopy is commonly used to identify microbes at species as well as subspecies level. In this study, we aimed to assess the suitability of FTIR spectroscopy as a tool for S. aureus subtyping. To this end, we compared the subtyping performance of FTIR spectroscopy to other subtyping methods such as pulsed field gel electrophoresis (PFGE) and spa typing in a blinded experimental setup and investigated the ability of FTIR spectroscopy for identifying S. aureus clonal complexes (CC). A total of 70 S. aureus strains from human, animal, and food sources were selected, for which clonal complexes and a unique virulence and resistance gene pattern had been determined by DNA microarray analysis. FTIR spectral analysis resulted in high discriminatory power similar as obtained by spa typing and PFGE. High directional concordance was found between FTIR spectroscopy based subtypes and capsular polysaccharide expression detected by FTIR spectroscopy and the cap specific locus, reflecting strain specific expression of capsular polysaccharides and/or other surface glycopolymers, such as wall teichoic acid, peptidoglycane, and lipoteichoic acid. Supervised chemometrics showed only limited possibilities for differentiation of S. aureus CC by FTIR spectroscopy with the exception of CC45 and CC705. In conclusion, FTIR spectroscopy represents a valuable tool for S. aureus subtyping, which complements current molecular and proteomic strain typing. PMID:27021524

  16. Campylobacter fetus Bacteremia Revealed by Cellulitis without Gastrointestinal Symptoms in the Context of Acquired Hypogammaglobulinemia: A Report of Three Cases

    Directory of Open Access Journals (Sweden)

    Souleymane Brah

    2011-01-01

    Full Text Available Campylobacter fetus bacteremia is rare and occurs mainly in patients with immunosuppression. This infection, which often involves secondary localizations has already been reported in some primary humoral immune deficiencies. We describe three cases of severe infection due to C. fetus with cellulitis at presentation, but without any gastrointestinal symptoms, occurring in patients with acquired hypogammaglobulinemia.

  17. 18F-FDG PET/CT for detection of metastatic infection in gram-positive bacteremia.

    NARCIS (Netherlands)

    Vos, F.J.; Bleeker-Rovers, C.P.; Sturm, P.D.J.; Krabbe, P.F.M.; Dijk, A.P.J. van; Cuijpers, M.L.H.; Adang, E.M.M.; Wanten, G.J.A.; Kullberg, B.J.; Oyen, W.J.G.

    2010-01-01

    The timely detection of metastatic infectious foci in gram-positive bacteremia is crucial, because these foci often require prolonged antibiotic treatment or drainage. The diagnosis of metastatic infectious foci is difficult because localizing symptoms are often absent. We investigated whether (18)F

  18. 18F-FDG PET/CT for detection of metastatic infection in gram-positive bacteremia

    NARCIS (Netherlands)

    Vos, Fidel J; Bleeker-Rovers, Chantal P; Sturm, Patrick D; Krabbe, Paul F M; van Dijk, Arie P J; Cuijpers, Maria L H; Adang, Eddy M M; Wanten, Geert J A; Kullberg, Bart-Jan; Oyen, Wim J G

    2010-01-01

    UNLABELLED: The timely detection of metastatic infectious foci in gram-positive bacteremia is crucial, because these foci often require prolonged antibiotic treatment or drainage. The diagnosis of metastatic infectious foci is difficult because localizing symptoms are often absent. We investigated w

  19. (18)F-FDG PET/CT for detection of metastatic infection in gram-positive bacteremia

    NARCIS (Netherlands)

    Vos, F.J.; Bleeker-Rovers, C.P.; Sturm, P.D.; Krabbe, P.F.M.; Van Dijk, A. P. J.; Cuijpers, M.L.H.; Adang, E.M.M.; Wanten, G.J.A.; Kullberg, B.J.; Oyen, W.J.G.

    2010-01-01

    The timely detection of metastatic infectious foci in gram-positive bacteremia is crucial, because these foci often require prolonged antibiotic treatment or drainage. The diagnosis of metastatic infectious foci is difficult because localizing symptoms are often absent. We investigated whether (18)F

  20. Nosocomial extended-spectrum beta-lactamase-producing Klebsiella pneumoniae bacteremia in hemodialysis patients and the implications for antibiotic therapy

    Directory of Open Access Journals (Sweden)

    Chih-Chao Yang

    2014-11-01

    Conclusions: In accordance with our previous study, our results have demonstrated the inferiority of flomoxef to carbapenems in the treatment of HD access-related ESBL-Kp bacteremia and provide an insight into the possibility of using ertapenem rather than flomoxef as an initial or de-escalating therapy for infections caused by ESBL-producing bacteria.

  1. Serial and panel analyses of biomarkers do not improve the prediction of bacteremia compared to one procalcitonin measurement

    NARCIS (Netherlands)

    Tromp, M.; Lansdorp, B.; Bleeker-Rovers, C.P.; Klein Gunnewiek, J.M.; Kullberg, B.J.; Pickkers, P.

    2012-01-01

    Objectives We evaluated the value of a single biomarker, biomarker panels, biomarkers combined with clinical signs of sepsis, and serial determinations of biomarkers in the prediction of bacteremia in patients with sepsis. Methods Adult patients visiting the emergency department because of a susp

  2. Serial and panel analyses of biomarkers do not improve the prediction of bacteremia compared to one procalcitonin measurement.

    NARCIS (Netherlands)

    Tromp, M.; Lansdorp, B.; Bleeker-Rovers, C.P.; Gunnewiek, J.M.; Kullberg, B.J.; Pickkers, P.

    2012-01-01

    OBJECTIVES: We evaluated the value of a single biomarker, biomarker panels, biomarkers combined with clinical signs of sepsis, and serial determinations of biomarkers in the prediction of bacteremia in patients with sepsis. METHODS: Adult patients visiting the emergency department because of a suspe

  3. First report of neonatal bacteremia caused by "Haemophilus quentini" diagnosed by 16S rRNA gene sequencing, Italy.

    Science.gov (United States)

    Giufrè, Maria; Cardines, Rita; Degl'Innocenti, Roberto; Cerquetti, Marina

    2015-10-01

    We report the first case of neonatal bacteremia caused by a "Haemophilus quentini" isolate in Italy. The isolate was differentiated from H. influenzae by 16S rRNA sequencing and was characterized by comparison with the wild-type "H. quentini" CCUG 36167. Both isolates carried substitutions in penicillin-binding protein 3 but were susceptible to aminopenicillins.

  4. Mycobacterium tuberculosis bacteremia diagnosed in an HIV-negative patient in Brazil: a rare or an under-reported event?

    Directory of Open Access Journals (Sweden)

    D. J. Hadad

    2004-04-01

    Full Text Available A case of Mycobacterium tuberculosis bacteremia in an HIV negative immunodepressed patient was described using the BACTEC 460 TB system. This bacterium should be investigated in the blood of immunodepressed non-HIV infected patients with prolonged fever.

  5. Isolation of Yokenella regensburgei ("Koserella trabulsii") from a patient with transient bacteremia and from a patient with a septic knee.

    OpenAIRE

    Abbott, S L; Janda, J M

    1994-01-01

    Yokenella regensburgei ("Koserella trabulsii") was isolated from a 74-year-old male with a septic knee and from a 35-year-old immunocompromised female whose transient bacteremia occurred without overt signs of sepsis. Neither strain was correctly identified by laboratories using a variety of techniques.

  6. Lymphocytopenia and neutrophil-lymphocyte count ratio predict bacteremia better than conventional infection markers in an emergency care unit

    NARCIS (Netherlands)

    C.P.C. de Jager; P.T.I. van Wijk; R.B. Mathoera; J. de Jongh-Leuvenink; T. van der Poll; P.C. Wever

    2010-01-01

    Introduction: Absolute lymphocytopenia has been reported as a predictor of bacteremia in medical emergencies. Likewise, the neutrophil-lymphocyte count ratio (NLCR) has been shown a simple promising method to evaluate systemic inflammation in critically ill patients. Methods: We retrospectively eval

  7. Central venous catheter-related bacteremia caused by Kocuria kristinae: Case report and review of the literature

    Directory of Open Access Journals (Sweden)

    David Michael Z

    2011-08-01

    Full Text Available Abstract Kocuria species are unusual human pathogens isolated most commonly from immunocompromised hosts, such as transplant recipients and cancer patients undergoing chemotherapy, or from patients with chronic medical conditions. A case of catheter-related bacteremia with pulmonary septic emboli in a pregnant adult female without chronic medical conditions is described. A review of other reported Kocuria infections is provided.

  8. Bacteria causing bacteremia in pediatric cancer patients presenting with febrile neutropenia-species distribution and susceptibility patterns

    NARCIS (Netherlands)

    Miedema, Karin G. E.; Winter, Rik H. L. J.; Ammann, Roland A.; Droz, Sara; Spanjaard, Lodewijk; de Bont, Eveline S. J. M.; Kamps, Willem A.; van de Wetering, Marianne D.; Tissing, Wim J. E.

    2013-01-01

    Infections are a major cause of morbidity and mortality in pediatric cancer patients. The aim of this study was to establish the microbiological spectrum and the susceptibility patterns of bacteremia-causing bacteria in pediatric cancer patients with febrile neutropenia in relation to the use of pro

  9. Early vancomycin-resistant enterococcus (VRE) bacteremia after allogeneic bone marrow transplantation is associated with a rapidly deteriorating clinical course.

    Science.gov (United States)

    Avery, R; Kalaycio, M; Pohlman, B; Sobecks, R; Kuczkowski, E; Andresen, S; Mossad, S; Shamp, J; Curtis, J; Kosar, J; Sands, K; Serafin, M; Bolwell, B

    2005-03-01

    Vancomycin-resistant enterococcal (VRE) infection is a growing threat. We studied the incidence, risk factors, and clinical course of early-onset VRE bacteremia in allogeneic hematopoietic stem cell transplant recipients. We carried out a chart review of 281 allogeneic hematopoietic stem cell transplant recipients from 1997-2003, including preparative regimen, diagnosis, status of disease, graft-versus-host disease prophylaxis, antimicrobial therapy, and survival. VRE bacteremia developed in 12/281 (4.3%) recipients; 10 (3.6%) were within 21 days of transplant. Diagnoses were acute leukemia (7), NHL (2), and MDS (1). In all, 70% had refractory/relapsed disease; 30% were in remission. In total, 50% had circulating blasts. Nine of 10 had matched unrelated donors (7/9 with CD8+ T-cell depletion). The average time to positive VRE cultures was 15 days; average WBC was 0.05, and 80% had concomitant infections. Despite treatment, all patients died within 73 days of VRE bacteremia. Intra-abdominal complications were common. Causes of death included bacterial or fungal infection, multiorgan failure, VOD, ARDS, and relapse. A total of 60% of patients engrafted neutrophils, but none engrafted platelets. Early VRE bacteremia after allogeneic bone marrow transplant is associated with a rapidly deteriorating clinical course, although not always directly due to VRE. Early VRE may be a marker for the critical condition of these high-risk patients at the time of transplant. PMID:15640812

  10. Significance of biopterin induction in rats with postburn Staphylococcus aureus sepsis

    Institute of Scientific and Technical Information of China (English)

    Li Hongyun; Yao Yongming; Shi Zhiguo; Dong Ning; Yu Yan; Lu Lianrong; Sheng Zhiyong

    2002-01-01

    Objective: It has been demonstrated that biopterin, an essential cofactor of nitric oxide synthase (NOS), plays an important role in the pathogenesis of endotoxin-induced shock, yet its biological significance in gram-positive sepsis remains unclear. In this study, we adopted a rat model of postburn Staphylococcus aureus (S.aureus) sepsis to observe the time course and tissue distribution of biopterin in postburn S. aureus infection, and to investigate its potential role in the pathogenesis of gram-positive sepsis. Wistar rats were inflicted with a 20% total body surface area (TBSA) full-chickness scald injury followed by S. aureus challenge, then guanosine triphosphatecyclohydrolase I (GTP-CHI) mRNA expression and biopterin levels in liver, kidneys, lungs and heart were determined at 0. 5, 2, 6, 12 and 24 hours after S. aureus challenge. We found that after S. aureus challenge, GTP-CHI gene expressions and biopterin levels were markedly up-regulated in various tissues, and remained at high values up to 24 hours (P< 0. 05-0.01). Meanwhile, the organ function indexes, including serum alanine amimotransferase (ALT), aspartate aminotransferase (AST), creatinine (Cr), MB isoenzyme of creatine kinase (CK-MB), levels and pulmonary myeloperoxidase (MPO) activities significantly increased at 24 hours postburn, and the multiple organ dysfunction was aggravated by S. aureus challenge. Moreover, it was shown that cardiac GTP-CHI mRNA expression and renal BH4levels were positively correlated with CK-MB and Cr (r=0. 892, P=0. 0012 and r=0. 9423,P=0.0015, respectively). Conclusion: These results suggested that thermal injury combined with S. aureus challenge could induce de novo biosynthesis of biopterin, which acts as the most important cofactor of iNOS, might play a role in the development of multiple organ dysfunction syndrome secondary to postburn sepsis.

  11. Immunomodulation and Disease Tolerance to Staphylococcus aureus

    OpenAIRE

    Zhigang Li; Peres, Adam G.; Andreea C. Damian; Joaquín Madrenas

    2015-01-01

    The Gram-positive bacterium Staphylococcus aureus is one of the most frequent pathogens that causes severe morbidity and mortality throughout the world. S. aureus can infect skin and soft tissues or become invasive leading to diseases such as pneumonia, endocarditis, sepsis or toxic shock syndrome. In contrast, S. aureus is also a common commensal microbe and is often part of the human nasal microbiome without causing any apparent disease. In this review, we explore the immunomodulation and d...

  12. Postoperative Staphylococcus aureus infections in Medicare beneficiaries.

    Directory of Open Access Journals (Sweden)

    Moaven Razavi

    Full Text Available Staphylococcus aureus (S. aureus infections are important because of their increasing frequency, resistance to antibiotics, and high associated rates of disabilities and deaths. We examined the incidence and correlates of S. aureus infections following 219,958 major surgical procedures in a 5% random sample of fee-for-service Medicare beneficiaries from 2004-2007. Of these surgical patients, 0.3% had S. aureus infections during the hospitalizations when index surgical procedures were performed; and 1.7% and 2.3%, respectively, were hospitalized with infections within 60 days or 180 days following admissions for index surgeries. S. aureus infections occurred within 180 days in 1.9% of patients following coronary artery bypass graft surgery, 2.3% following hip surgery, and 5.9% following gastric or esophageal surgery. Of patients first hospitalized with any major infection reported during the first 180 days after index surgery, 15% of infections were due to S. aureus, 18% to other documented organisms, and no specific organism was reported on claim forms in 67%. Patient-level predictors of S. aureus infections included transfer from skilled nursing facilities or chronic hospitals and comorbid conditions (e.g., diabetes, congestive heart failure, chronic obstructive pulmonary disease, and chronic renal disease. In a logarithmic regression, elective index admissions with S. aureus infection stayed 130% longer than comparable patients without that infection. Within 180 days of the index surgery, 23.9% of patients with S. aureus infection and 10.6% of patients without this infection had died. In a multivariate logistic regression of death within 180 days of admission for the index surgery with adjustment for demographics, co-morbidities, and other risks, S. aureus was associated with a 42% excess risk of death. Due to incomplete documentation of organisms in Medicare claims, these statistics may underestimate the magnitude of S. aureus infection

  13. [Role of anaerobic blood culture in the simultaneous blood culture taking for the diagnosis of bacteremia].

    Science.gov (United States)

    Guajardo-Lara, Claudia Elena; Saldaña-Ramírez, Martha Idalia; Ayala-Gaytán, Juan Jacobo; Valdovinos-Chávez, Salvador Bruno

    2016-01-01

    Introducción: la frecuencia de la septicemia va en aumento y su mortalidad es alta; por lo tanto, su detección, la identificación del microorganismo causal y su susceptibilidad son perentorias. Metodos: se revisaron los registros de 4110 botellas de cultivo de sangre obtenida de enero de 2013 a julio de 2014 de pacientes adultos en un hospital privado de tercer nivel. Resultados: se observó crecimiento de microorganismos en 559 cultivos (12.6 %). En 2648 hemocultivos (60 %) inoculados en pares de frascos uno con medio aeróbico y el otro anaeróbico (1324 sets), se detectó crecimiento en 182 frascos a los que les fueron inoculadas las muestras tomadas al mismo tiempo a 135 pacientes (13.7 %). En 86 pares de frascos con las muestras de 54 pacientes (40 %), el crecimiento solamente se dio en el frasco aeróbico (47.5 %); en 24 pares de frascos (13.19 %) tomados a 21 pacientes (15.5 %, p crecimiento en el frasco anaeróbico. En los hemocultivos de 32 de 60 pacientes con crecimiento en ambos frascos (53 %), el crecimiento se detectó primero en el frasco anaeróbico. Conclusiones: los hemocultivos anaeróbicos tienen una utilidad baja para la detección de bacteriemias por anaerobios estrictos; no obstante, en el 15.55 % de los pacientes estuvo presente el riesgo de pasar por alto la presencia de bacteriemia, y en 53 % de los pacientes con hemocultivos positivos, el diagnóstico de bacteriemia pudo establecerse de manera más temprana, lo que permitió anticipar con mejor precisión la toma de decisiones.

  14. Serum procalcitonin elevation in elderly patients with coronary heart disease at the onset of septic shock caused by either Gram negative or Gram positive bacteremia

    Institute of Scientific and Technical Information of China (English)

    HUANG Dao-zheng; MA Huan; WANG Shou-hong; WU Yan; QIN Tie-he; TAN Ning

    2016-01-01

    Background Septic shock caused by bacteremia is a life-threatening infection whose prognosis is highly dependent on early recognition and appropriate treatment.Procalcitonin (PCT) has been shown to accurately and quickly distinguish bacteremia from noninfectious inflammatory states in critically severe patients.However,the extent of PCT magnitude elevation according to the Gram stain result in elderly patients with coronary heart disease (CHD) at the onset of septic shock caused by bacteremia varies,and has not been clearly elucidated.Methods The medical records of advanced age (non-neutropenic) patient with CHD and septic shock between Mar 2013 and Jun 2015 who had bacteremia caused by either Gram-positive (GP) bacteria or Gram-negative (GN) bacteria were reviewed,and the levels of PCT,C-reactive (CRP) protein and white blood cells count (WBC) in both groups were analyzed.Results 75 episodes of either GN bacteremia (n =40) or GP bacteremia (n =35) were enrolled.PCT levels were found to be markedly higher in patients with GN bacteremia than in those with GP bacteremia [(8.93 ± 17.58) vs.(64.42 ± 58.56) ng/L (P < 0.001)],whereas there was no significant difference in CRP and WBC (P > 0.05).Moreover,a high PCT level was found to be independently associated with GN bacteremia in this study population.A PCT level of 19.69 ng/mL yielded a 72.5% sensitivity,a 91.4% specificity,an 8.43 positive likelihood ratio and a 0.30 negative likelihood ratio for GN-related bacteremia in the study cohort [AUROCC =0.870 (0.041),95% CI (0.790-0.949)].Conclusion In an elderly patient (non-neutropenic)with CHD and septic shock,GN bacteremia could be associated with higher PCT values than those found in GP bacteremia (PCT > 19.69 ng/mL).

  15. Immunomodulation and Disease Tolerance to Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Zhigang Li

    2015-11-01

    Full Text Available The Gram-positive bacterium Staphylococcus aureus is one of the most frequent pathogens that causes severe morbidity and mortality throughout the world. S. aureus can infect skin and soft tissues or become invasive leading to diseases such as pneumonia, endocarditis, sepsis or toxic shock syndrome. In contrast, S. aureus is also a common commensal microbe and is often part of the human nasal microbiome without causing any apparent disease. In this review, we explore the immunomodulation and disease tolerance mechanisms that promote commensalism to S. aureus.

  16. Mastite com lesões sistêmicas por Staphylococus aureus subesp. aureus em coelhos Mastitis with systemic lesions due to Staphylococus aureus subesp. aureus in rabbits

    OpenAIRE

    Sandra Davi Traverso; Leonardo da Cunha; Joaquim César Teixeira Fernandes; Alexandre Paulino Loretti; Adriana Rhoden; Elsio Wunder Jr.; David Driemeier

    2003-01-01

    Em uma criação composta por 1800 coelhos, 33% das matrizes apresentaram mastite e lesões cutâneas crostosas e purulentas. Estes animais apresentavam-se entre 10 a- 12 meses de idade e em segunda parição. Quinze coelhos afetados foram sacrificados e necropsiados. Na necropsia, além das lesões cutâneas haviam microabscessos em diversos órgãos. Das amostras coletadas isolou-se Staphylococcus aureus subesp. aureus. S. aureus subesp. aureus também foi isolado de "swab" nasal coletado do tratador e...

  17. Methicillin-Resistant Staphylococcus aureus (MRSA) Treatment

    Science.gov (United States)

    ... Laboratory of Bacteriology Network on Antimicrobial Resistance in Staphylococcus aureus (NARSA) Antibacterial Resistance Leadership Group (ARLG) NIAID Antimicrobial Resistance Funding Information ...

  18. Methicillin-Resistant Staphylococcus aureus (MRSA) Diagnosis

    Science.gov (United States)

    ... Laboratory of Bacteriology Network on Antimicrobial Resistance in Staphylococcus aureus (NARSA) Antibacterial Resistance Leadership Group (ARLG) NIAID Antimicrobial Resistance Funding Information ...

  19. Differential Analysis of the Nasal Microbiome of Pig Carriers or Non-Carriers of Staphylococcus aureus.

    Science.gov (United States)

    Espinosa-Gongora, Carmen; Larsen, Niels; Schønning, Kristian; Fredholm, Merete; Guardabassi, Luca

    2016-01-01

    Staphylococcus aureus is presently regarded as an emerging zoonotic agent due to the spread of specific methicillin-resistant S. aureus (MRSA) clones in pig farms. Studying the microbiota can be useful for the identification of bacteria that antagonize such opportunistic veterinary and zoonotic pathogen in animal carriers. The aim of this study was to determine whether the nasal microbiome of pig S. aureus carriers differs from that of non-carriers. The V3-V5 region of the 16S rRNA gene was sequenced from nasal swabs of 44 S. aureus carriers and 56 non-carriers using the 454 GS FLX titanium system. Carriers and non-carriers were selected on the basis of quantitative longitudinal data on S. aureus carriage in 600 pigs sampled at 20 Danish herds included in two previous studies in Denmark. Raw sequences were analysed with the BION meta package and the resulting abundance matrix was analysed using the DESeq2 package in R to identify operational taxonomic units (OTUs) with differential abundance between S. aureus carriers and non-carriers. Twenty OTUs were significantly associated to non-carriers, including species with known probiotic potential and antimicrobial effect such as lactic acid-producing isolates described among Leuconostoc spp. and some members of the Lachnospiraceae family, which is known for butyrate production. Further 5 OTUs were significantly associated to carriage, including known pathogenic bacteria such as Pasteurella multocida and Klebsiella spp. Our results show that the nasal microbiome of pigs that are not colonized with S. aureus harbours several species/taxa that are significantly less abundant in pig carriers, suggesting that the nasal microbiota may play a role in the individual predisposition to S. aureus nasal carriage in pigs. Further research is warranted to isolate these bacteria and assess their possible antagonistic effect on S. aureus for the pursuit of new strategies to control MRSA in pig farming. PMID:27509169

  20. Effects of nisin on Staphylococcus aureus count and physicochemical properties of Minas Frescal cheese.

    Science.gov (United States)

    Felicio, Bruna A; Pinto, Maximiliano S; Oliveira, Francielly S; Lempk, Marcus W; Pires, Ana Clarissa S; Lelis, Carini A

    2015-07-01

    The aim of this work was to evaluate the effects of nisin on in vitro and in situ Staphylococcus aureus counts. For in vitro experiment, milk was inoculated with 5.0 log cfu·mL(-1) of S. aureus and nisin was added at concentrations of 0, 100, 200, 400, and 500 IU mL(-1). The main effect of the bacteriocin was lag phase extension from 0h, for 0 and 100 IU·mL(-1) to 8h, when 200, 400, and 500 IU·mL(-1) of nisin were used; however, log phase was not affected. Microbial growth rate was found to be exponential and around 0.11 log cfu·mL(-1)·h(-1) for all treatments. For in situ experiments, 0, 400, and 500 IU·mL(-1) of nisin were directly added to pasteurized milk previously inoculated with 5.0 log cfu·g(-1) of S. aureus. Milk, curd, and whey were analyzed to S. aureus counts. Nisin at concentration of 500 IU·mL(-1) was able to reduce S. aureus count in curd and whey, demonstrating nisin partition between both phases. Throughout storage at 4°C, S. aureus count increased for all treatments, but the bacterial grew slower when nisin was added in both concentrations, maintaining S. aureus count about 1.5 log cycles lower than the control, despite abusive initial S. aureus count. Therefore, nisin seems to play an important role in reducing S. aureus initial count in cheese made with highly contaminated milk. Nisin showed potential to be used as an additional, important hurdle to improve Minas Frescal cheese safety, without replacing good manufacturing practices.

  1. Differential Analysis of the Nasal Microbiome of Pig Carriers or Non-Carriers of Staphylococcus aureus

    Science.gov (United States)

    Espinosa-Gongora, Carmen; Larsen, Niels; Schønning, Kristian; Fredholm, Merete; Guardabassi, Luca

    2016-01-01

    Staphylococcus aureus is presently regarded as an emerging zoonotic agent due to the spread of specific methicillin-resistant S. aureus (MRSA) clones in pig farms. Studying the microbiota can be useful for the identification of bacteria that antagonize such opportunistic veterinary and zoonotic pathogen in animal carriers. The aim of this study was to determine whether the nasal microbiome of pig S. aureus carriers differs from that of non-carriers. The V3-V5 region of the 16S rRNA gene was sequenced from nasal swabs of 44 S. aureus carriers and 56 non-carriers using the 454 GS FLX titanium system. Carriers and non-carriers were selected on the basis of quantitative longitudinal data on S. aureus carriage in 600 pigs sampled at 20 Danish herds included in two previous studies in Denmark. Raw sequences were analysed with the BION meta package and the resulting abundance matrix was analysed using the DESeq2 package in R to identify operational taxonomic units (OTUs) with differential abundance between S. aureus carriers and non-carriers. Twenty OTUs were significantly associated to non-carriers, including species with known probiotic potential and antimicrobial effect such as lactic acid-producing isolates described among Leuconostoc spp. and some members of the Lachnospiraceae family, which is known for butyrate production. Further 5 OTUs were significantly associated to carriage, including known pathogenic bacteria such as Pasteurella multocida and Klebsiella spp. Our results show that the nasal microbiome of pigs that are not colonized with S. aureus harbours several species/taxa that are significantly less abundant in pig carriers, suggesting that the nasal microbiota may play a role in the individual predisposition to S. aureus nasal carriage in pigs. Further research is warranted to isolate these bacteria and assess their possible antagonistic effect on S. aureus for the pursuit of new strategies to control MRSA in pig farming. PMID:27509169

  2. Characterisation of Staphylococcus aureus bacteraemia at Tygerberg hospital

    NARCIS (Netherlands)

    Orth, H.; Dreyer, Z.S.; Makgotlho, E.; Oosthuysen, W.; Sinha, B.; Wasserman, E.

    2013-01-01

    To elucidate the local epidemiology of Staphylococcus aureus bacteraemia, we characterised blood culture isolates using molecular methods and prospectively collected clinical data to determine the occurrence of community-acquired, methicillinresistant S. aureus (MRSA). Consecutive S. aureus blood cu

  3. Evaluation of Two New Chromogenic Media, CHROMagar MRSA and S. aureus ID, for Identifying Staphylococcus aureus and Screening Methicillin-Resistant S. aureus

    OpenAIRE

    Hedin, Göran; Fang, Hong

    2005-01-01

    Thirty-nine methicillin-resistant Staphylococcus aureus (MRSA) isolates with diverse genetic backgrounds and two reference strains were correctly identified as S. aureus on CHROMagar MRSA and S. aureus ID media. Growth inhibition on CHROMagar MRSA was noted. A combination of cefoxitin disk and S. aureus ID was found suitable for rapid MRSA screening.

  4. Bacteremia due to Acinetobacter ursingii in infants: Reports of two cases

    Science.gov (United States)

    Yakut, Nurhayat; Kepenekli, Eda Kadayifci; Karaaslan, Ayse; Atici, Serkan; Akkoc, Gulsen; Demir, Sevliya Ocal; Soysal, Ahmet; Bakir, Mustafa

    2016-01-01

    Acinetobacter ursingii is an aerobic, gram-negative, opportunistic microorganism which is rarely isolated among Acinetobacter species. We present two immunocompetent infants who developed bacteremia due to A. ursingii. The first patient is a two -month- old boy who had been hospitalized in pediatric surgery unit for suspected tracheo-esophageal fistula because of recurrent aspiration pneumonia unresponsive to antibiotic therapy. The second patient is a fourteen -month- old boy with prolonged vomiting and diarrhea. A. ursingii was isolated from their blood cultures. They were successfully treated with ampicillin-sulbactam. Although A. ursingii has recently been isolated from a clinical specimen; reports of infection with A. ursingii in children are rare. A. ursingii should be kept in mind as an opportunistic microorganism in children. PMID:27347282

  5. Treatment of Haemophilus bacteremia with benzylpenicillin is associated with increased (30-day mortality

    Directory of Open Access Journals (Sweden)

    Thønnings Sara

    2012-07-01

    Full Text Available Abstract Background Optimal antibiotic treatment strategies of Haemophilus infections are still needed. Therefore, 30-day case fatality rate (CFR of Haemophilus bacteremia and efficacy of various antibiotic treatment regimes were studied. Methods All episodes of Haemophilus bacteremia in the former Copenhagen County during the period 2000-9 were included in the study. Clinical and biochemical findings and outcome were collected retrospectively from medical records. Results 105 consecutive episodes were identified (median age: 69 years, with only 4 children H. influenzae, and 11% to other Haemophilus species. Pneumonia was the most common primary focus (in 48%, and 58% of the patients had Charlson comorbidity index > 1. Definitive antibiotic therapy was in 26 cases benzylpenicillin, in 12 cases aminopenicillins, in 50 cases cefuroxime and in 16 cases broadspectrum antibiotics, whereas 1 palliative case died without start of therapy. Whereas the use of broadspectrum antibiotics was related to the severity of the disease (admittance to ICU, need for assisted ventilation or hemodialysis, septic shock, no significant difference in clinical features was demonstrated for therapy with benzylpenicillin, aminopenicillin or cefuroxime, except benzylpenicillin was rarely administered to immunosuppressed patients. The CFR was 22% (23/105. The choice of empiric antibiotic therapy was not significantly associated with mortality (adequate vs. inadequate treatment: 23% (21/93 vs. 17% (2/12, respectively, P > 0.05. In contrast, definite antibiotic therapy with cefuroxime or aminopenicillins resulted in a significantly lower CFR than treatment with benzylpenicillin (12% (6/50 or 0% (0/12 vs. 39% (10/26, respectively, Log rank test P  0.02. When adjustments were made for other identified risk factors in bivariate logistic regression analysis, treatment with cefuroxime was still were found to be associated with a significantly lower CFR than for

  6. An Arthrobacter spp. bacteremia leading to fetal death and maternal disseminated intravascular coagulation.

    Science.gov (United States)

    Shigeta, Naoya; Ozaki, Kimiaki; Hori, Kensuke; Ito, Kimihiko; Nakayama, Masahiro; Nakahira, Kumiko; Yanagihara, Itaru

    2013-02-01

    A 34-year-old parous woman developed high fever and threatened preterm labor after a 1-day trip, for which she was receiving prenatal care at a hospital. Three days after onset, at 24 4/7 weeks of gestation, she was transferred to our hospital in an emergency. Soon after the woman's arrival at our hospital, the infant was spontaneously stillborn via a transvaginal delivery. Laboratory tests revealed severe maternal disseminated intravascular coagulation with renal and liver insufficiency. Histopathologic examination of the placenta revealed vast fibrin deposition and remarkable neutrophilic infiltration in the intervillous space, suggesting a rare bacterial infection caused by Arthrobacter spp. The bacteria were predominantly detected in the placenta and maternal blood serum by common bacterial 16S rRNA sequencing after polymerase chain reaction amplification. We report the first case, to our knowledge, of bacteremia with Arthrobacter spp., which may lead to maternal disseminated intravascular coagulation and intrauterine fetal death.

  7. Capnocytophaga ochracea-related Bacterium Bacteremia in a Hypertrophic Cardiomyopathy Patient without Neutropenia.

    Science.gov (United States)

    Ito, Shimpei; Hagiya, Hideharu; Kimura, Keigo; Nishi, Isao; Yoshida, Hisao; Kioka, Hidetaka; Ohtani, Tomohito; Yamaguchi, Osamu; Tanabe, Kazuaki; Tomono, Kazunori; Sakata, Yasushi

    2016-01-01

    Gram-negative fusiform rods were detected in a blood culture obtained from a 63-year-old man who had been hospitalized for a long duration for severe heart failure. Although the organism could not be identified using a conventional method, it was finally identified as a bacterium of the Capnocytophaga ochracea group based on the results of biochemical testing, 16S rRNA sequencing and a matrix-assisted laser desorption ionization time-of-flight mass spectrometry analysis. Although neutropenic patients with poor oral hygiene are exclusively vulnerable to Capnocytophaga bacteremia, this case was unique because such predisposing conditions were not noted. A multi-centered investigation is warranted for a better understanding of this clinically rare, but potentially pathogenic organism. PMID:27629977

  8. Epidemiology of Haemophilus influenzae bacteremia: A multi-national population-based assessment

    DEFF Research Database (Denmark)

    Laupland, Kevin B; Schønheyder, Henrik C; Østergaard, Christian;

    2011-01-01

    OBJECTIVES: Haemophilus influenzae is an important cause of invasive infection but contemporary data in non-selected populations is limited. METHODS: Population-based surveillance for Haemophilus influenzae bacteremia was conducted in seven regions in Australia, Canada, and Denmark during 2000...... independently associated with death at 30-days in logistic regression analysis included male gender, hospital-onset disease, older age, and lower respiratory tract, central nervous system, or unknown focus of infection. CONCLUSIONS: Haemophilus influenzae is an important cause of morbidity and mortality......-2008. RESULTS: The overall annual incidence rate was 1.31 per 100,000 population and type specific rates were 0.08 for H. influenzae serotype b (Hib), 0.22 for H. influenzae serotypes a, c-f (Hiac-f), and 0.98 per 100,000 for non-typeable H. influenzae (NTHi). Very young and old patients were at highest risk...

  9. Immunogenicity of toxins during Staphylococcus aureus infection

    NARCIS (Netherlands)

    N.J. Verkaik (Nelianne); O. Dauwalder (Olivier); K. Antri (Kenza); I. Boubekri (Ilhem); C.P. de Vogel (Corné); C. Badiou (Cédric); M. Bes (Michèle); F. Vandenesch (François); M. Tazir (Mohammed); H. Hooijkaas (Herbert); H.A. Verbrugh (Henri); A.F. van Belkum (Alex); J. Etienne (Jerome); G. Lina (Gérard); N. Ramdani-Bouguessa (Nadjia); W.J.B. van Wamel (Willem)

    2010-01-01

    textabstractAB - BACKGROUND: Toxins are important Staphylococcus aureus virulence factors, but little is known about their immunogenicity during infection. Here, additional insight is generated. METHODS: Serum samples from 206 S. aureus-infected patients and 201 hospital-admitted control subjects we

  10. The cell surface proteome of Staphylococcus aureus

    NARCIS (Netherlands)

    Dreisbach, Annette; van Dijl, Jan Maarten; Buist, Girbe

    2011-01-01

    The Gram-positive bacterium Staphylococcus aureus is a wide spread opportunistic pathogen that can cause a range of life-threatening diseases. To obtain a better understanding of the global mechanisms for pathogenesis and to identify novel targets for therapeutic interventions, the S. aureus proteom

  11. Population structure of Staphylococcus aureus in China

    NARCIS (Netherlands)

    Yan, Xiaomei

    2015-01-01

    The present PhD research was aimed at analysing the population structure of Staphylococcus aureus in China. Between 2000 and 2005 we found that patients from a single Chinese hospital showed increasing trends in antimicrobial resistance. Among methicillin-resistant S. aureus (MRSA), resistance again

  12. Animal models of hematogenous Staphylococcus aureus osteomyelitis in long bones: a review

    Directory of Open Access Journals (Sweden)

    Johansen LK

    2013-08-01

    Full Text Available Louise Kruse Johansen, Henrik Elvang JensenDepartment of Veterinary Disease Biology, Faculty of Health and Medical Science, University of Copenhagen, Frederiksberg, DenmarkAbstract: Hematogenous osteomyelitis (HO, especially due to Staphylococcus aureus, is primarily reported in children and occurs when blood-borne bacteria settle in the metaphysis of a long bone and mediate an inflammatory response. The literature contains several reports on animal models aiming to simulate pediatric HO, in order to investigate the pathogenesis and for therapeutic use. In these models, osteomyelitis lesions develop subsequently to bacteremia, which can be induced by either intravenous or intra-arterial inoculation of bacteria. Intravenous inoculation is not optimal because of the ethical aspects of the extensive systemic reaction and the unpredictable identity of bones being infected. Also, intravenous inoculation often has to be combined with the induction of artificial bone necrosis in order to have macroscopic lesions. In contrast, models based on intra-arterial inoculation and subsequent development of local osteomyelitis, are the most accurate and predictable way to extrapolate to pediatric cases of HO. The most commonly used animal species for modeling of HO are rabbits, chickens, and mice, whereas, less frequently, dogs, rats, and pigs have been applied. The use of intra-arterial inoculation, without simultaneous artificial bone necrosis for the development of HO lesions has only been used in porcine models. Because of the similarity of human and porcine physiology, metabolic rate, and size, porcine models of HO are advantageous. Therefore, porcine models based on the intra-arterial induction of osteomyelitis are the most refined HO models.Keywords: hematogenous osteomyelitis, animal models, Staphylococcus aureus

  13. Morphological and molecular imaging of hematogenously inoculated and disseminated Staphylococcus aureus lesions in domestic juvenile female pigs by PET/CT. The bio-distribution of the radionuclides 18F-FDG, 11C-methionine, 11C-PK11195, and 68Ga-citrate in pigs is presented

    DEFF Research Database (Denmark)

    Afzelius, Pia; Nielsen, Ole Lerberg; Alstrup, Aage Kristian Olsen;

    2016-01-01

    . Bacteremia may give rise to bacterial spread to different tissues such as e.g. heart, joints, spleen, bones, and skin/soft tissue. Staphylococcus aureus is a conditional pathogen: it is carried on many humans and animals without symptoms, but it is also able to cause serious diseases like osteomyelitis...... tracers that potentially could improve uncovering of infectious lesions in soft tissues. We chose 11C-methionine, 11C-PK11195, and 68Ga-citrate as tracers and validated their diagnostic utility in a porcine model. Four juvenile 14-15 weeks old female domestic pigs were scanned seven days after intra...

  14. Outcomes and Risk Factors for Mortality among Patients Treated with Carbapenems for Klebsiella spp. Bacteremia

    Science.gov (United States)

    Biehle, Lauren R.; Cottreau, Jessica M.; Thompson, David J.; Filipek, Rachel L.; O’Donnell, J. Nicholas; Lasco, Todd M.; Mahoney, Monica V.; Hirsch, Elizabeth B.

    2015-01-01

    Background Extensive dissemination of carbapenemase-producing Enterobacteriaceae has led to increased resistance among Klebsiella species. Carbapenems are used as a last resort against resistant pathogens, but carbapenemase production can lead to therapy failure. Identification of risk factors for mortality and assessment of current susceptibility breakpoints are valuable for improving patient outcomes. Aim The objective of this study was to evaluate outcomes and risk factors for mortality among patients treated with carbapenems for Klebsiella spp. bacteremia. Methods Patients hospitalized between 2006 and 2012 with blood cultures positive for Klebsiella spp. who received ≥ 48 hours of carbapenem treatment within 72 hours of positive culture were included in this retrospective study. Patient data were retrieved from electronic medical records. Multivariate logistic regression was used to identify risk factors for 30-day hospital mortality. Results One hundred seven patients were included. The mean patient age was 61.5 years and the median APACHE II score was 13 ± 6.2. Overall, 30-day hospital mortality was 9.3%. After adjusting for confounding variables, 30-day mortality was associated with baseline APACHE II score (OR, 1.17; 95% CI, 1.01–1.35; P = 0.03), length of stay prior to index culture (OR, 1.03; 95% CI, 1.00–1.06; P = 0.04), and carbapenem non-susceptible (imipenem or meropenem MIC > 1 mg/L) infection (OR, 9.08; 95% CI, 1.17–70.51; P = 0.04). Conclusions Baseline severity of illness and length of stay prior to culture were associated with 30-day mortality and should be considered when treating patients with Klebsiella bacteremia. These data support the change in carbapenem breakpoints for Klebsiella species. PMID:26618357

  15. Deficiency of the Complement Component 3 but Not Factor B Aggravates Staphylococcus aureus Septic Arthritis in Mice.

    Science.gov (United States)

    Na, Manli; Jarneborn, Anders; Ali, Abukar; Welin, Amanda; Magnusson, Malin; Stokowska, Anna; Pekna, Marcela; Jin, Tao

    2016-04-01

    The complement system plays an essential role in the innate immune response and protection against bacterial infections. However, detailed knowledge regarding the role of complement in Staphylococcus aureus septic arthritis is still largely missing. In this study, we elucidated the roles of selected complement proteins in S. aureus septic arthritis. Mice lacking the complement component 3 (C3(-/-)), complement factor B (fB(-/-)), and receptor for C3-derived anaphylatoxin C3a (C3aR(-/-)) and wild-type (WT) control mice were intravenously or intra-articularly inoculated with S. aureus strain Newman. The clinical course of septic arthritis, as well as histopathological and radiological changes in joints, was assessed. After intravenous inoculation, arthritis severity and frequency were significantly higher in C3(-/-)mice than in WT controls, whereas fB(-/-)mice displayed intermediate arthritis severity and frequency. This was in accordance with both histopathological and radiological findings. C3, but not fB, deficiency was associated with greater weight loss, more frequent kidney abscesses, and higher bacterial burden in kidneys. S. aureus opsonized with C3(-/-)sera displayed decreased uptake by mouse peritoneal macrophages compared with bacteria opsonized with WT or fB(-/-)sera. C3aR deficiency had no effect on the course of hematogenous S. aureus septic arthritis. We conclude that C3 deficiency increases susceptibility to hematogenous S. aureus septic arthritis and impairs host bacterial clearance, conceivably due to diminished opsonization and phagocytosis of S. aureus. PMID:26787717

  16. Deficiency of the Complement Component 3 but Not Factor B Aggravates Staphylococcus aureus Septic Arthritis in Mice.

    Science.gov (United States)

    Na, Manli; Jarneborn, Anders; Ali, Abukar; Welin, Amanda; Magnusson, Malin; Stokowska, Anna; Pekna, Marcela; Jin, Tao

    2016-04-01

    The complement system plays an essential role in the innate immune response and protection against bacterial infections. However, detailed knowledge regarding the role of complement in Staphylococcus aureus septic arthritis is still largely missing. In this study, we elucidated the roles of selected complement proteins in S. aureus septic arthritis. Mice lacking the complement component 3 (C3(-/-)), complement factor B (fB(-/-)), and receptor for C3-derived anaphylatoxin C3a (C3aR(-/-)) and wild-type (WT) control mice were intravenously or intra-articularly inoculated with S. aureus strain Newman. The clinical course of septic arthritis, as well as histopathological and radiological changes in joints, was assessed. After intravenous inoculation, arthritis severity and frequency were significantly higher in C3(-/-)mice than in WT controls, whereas fB(-/-)mice displayed intermediate arthritis severity and frequency. This was in accordance with both histopathological and radiological findings. C3, but not fB, deficiency was associated with greater weight loss, more frequent kidney abscesses, and higher bacterial burden in kidneys. S. aureus opsonized with C3(-/-)sera displayed decreased uptake by mouse peritoneal macrophages compared with bacteria opsonized with WT or fB(-/-)sera. C3aR deficiency had no effect on the course of hematogenous S. aureus septic arthritis. We conclude that C3 deficiency increases susceptibility to hematogenous S. aureus septic arthritis and impairs host bacterial clearance, conceivably due to diminished opsonization and phagocytosis of S. aureus.

  17. Determinants of mortality in oncology patients colonized or infected with Staphylococcus aureus Determinantes de mortalidade em pacientes colonizados ou infectados por internados em um hospital do câncer. Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Luiz Claudio Santos Thuler

    1999-04-01

    Full Text Available Oxacillin-resistant Staphylococcus aureus (ORSA infection is an important cause of hospital morbidity and mortality. The objective of this study was to identify the main factors associated with death in patients colonized or infected with Staphylococcus aureus in a cancer center. A matched-pair case-control study enrolled all patients infected or colonized with ORSA (cases admitted to the Hospital do Câncer in Rio de Janeiro from 01/01/1992 to 12/31/1994. A control was defined as a patient hospitalized during the same period as the case-patients and colonized or infected with oxacillin-susceptible Staphylococcus aureus (OSSA. The study enrolled 95 cases and 95 controls. Patient distribution was similar for the two groups (p > or = 0.05 with respect to gender, underlying diseases, hospital transfer, prior infection, age, temperature, heart and respiratory rates, neutrophil count, and duration of hospitalization. Univariate analysis of putative risk factors associated with mortality showed the following significant variables: admission to the intensive care unit (ICU, presence of bacteremia, use of central venous catheter (CVC, ORSA colonization or infection, pneumonia, use of urinary catheter, primary lung infection, prior use of antibiotics, mucositis, and absence of cutaneous abscesses. Multivariate analysis showed a strong association between mortality and the following independent variables: admission to ICU (OR [odds ratio]=7.2, presence of Staphylococcus bacteremia (OR=6.8, presence of CVC (OR=5.3, and isolation of ORSA (OR=2.7. The study suggests a higher virulence of ORSA in comparison to OSSA in cancer patients.As infecções causadas por Staphylococcus aureus resistentes à oxacilina (ORSA são causas importantes de morbidade e mortalidade. O objetivo do estudo foi identificar os principais fatores associados à mortalidade em pacientes colonizados ou infectados por Staphylococcus aureus em um hospital de câncer. Foi realizado um

  18. Invasive Community-Acquired Methicillin-Resistant Staphylococcus aureus in a Japanese Girl with Disseminating Multiple Organ Infection: A Case Report and Review of Japanese Pediatric Cases

    Directory of Open Access Journals (Sweden)

    Ryuta Yonezawa

    2015-01-01

    Full Text Available Pediatric invasive community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA infection is very serious and occasionally fatal. This infectious disease is still a relatively rare and unfamiliar infectious disease in Japan. We report a positive outcome in a 23-month-old Japanese girl with meningitis, osteomyelitis, fasciitis, necrotizing pneumonia, urinary tract infection, and bacteremia due to CA-MRSA treated with linezolid. PCR testing of the CA-MRSA strain was positive for PVL and staphylococcal enterotoxin b and negative for ACME. SCC mec was type IVa. This case underscores the selection of effective combinations of antimicrobial agents for its treatment. We need to be aware of invasive CA-MRSA infection, which rapidly progresses with a serious clinical course, because the incidence of the disease may be increasing in Japan.

  19. Binding of Efb from Staphylococcus aureus to fibrinogen blocks neutrophil adherence

    Science.gov (United States)

    In addition to its pivotal role in hemostasis, fibrinogen (Fg) and provisional fibrin matrices play important roles in inflammation and regulate innate immune responses by interacting with leukocytes. Efb (the extracellular fibrinogen-binding protein) is a secreted Staphylococcus aureus protein that...

  20. An Acute Ibuprofen Overdose Masking a Severe Staphylococcus aureus Meningitis: A Case Report

    Directory of Open Access Journals (Sweden)

    Matthew Smetana

    2013-01-01

    Full Text Available Acute bacterial meningitis has a low incidence (3/100,000 in the United States and yet high fatality rate (approximately 14–16% and classically presents as a triad of fever, neck stiffness, and altered mental status. However, less than half of patients with meningitis present with this classic triad. We present the clinical course of a patient who initially presented to the emergency department after overdosing on ibuprofen for what he described as back pain secondary to mechanical injury. However, the patient's condition quickly deteriorated: he developed tachycardia, mental status changes, was intubated due to respiratory distress, and then suffered an 8-minute PEA arrest before return of spontaneous circulation was achieved. After the patient was stabilized, in addition to the nonsteroidal anti-inflammatory drug (NSAID overdose Staphylococcus aureus meningitis, bacteremia, and pneumonia were diagnosed. We report this case to illustrate that the initial presentation of meningitis may be extremely unusual especially in the setting of NSAID overdose and the acutely decompensating patient. As the risk of adverse clinical outcomes increases with delays in appropriate antibiotic therapy, it is therefore crucial to recognize the many signs and symptoms of meningitis, typical and atypical, and quickly begin appropriate treatment.

  1. Ongoing Horizontal and Vertical Transmission of Virulence Genes and papA Alleles among Escherichia coli Blood Isolates from Patients with Diverse-Source Bacteremia

    OpenAIRE

    Johnson, James R.; O'Bryan, Timothy T.; Kuskowski, Michael; Maslow, Joel N.

    2001-01-01

    The phylogenetic distributions of multiple putative virulence factors (VFs) and papA (P fimbrial structural subunit) alleles among 182 Escherichia coli blood isolates from patients with diverse-source bacteremia were defined. Phylogenetic correspondence among these strains, the E. coli Reference (ECOR) collection, and other collections of extraintestinal pathogenic E. coli (ExPEC) was assessed. Although among the 182 bacteremia isolates phylogenetic group B2 predominated, exhibited the greate...

  2. A new lipase as a pharmaceutical target for battling infections caused by Staphylococcus aureus: Gene cloning and biochemical characterization.

    Science.gov (United States)

    Ünlü, Aişe; Tanriseven, Aziz; Sezen, I Yavuz; Çelik, Ayhan

    2015-01-01

    Staphylococcus aureus lipases along with other cell-wall-associated proteins and enzymes (i.e., catalase, coagulase, protease, hyaluronidase, and β-lactamase) play important roles in the pathogenesis of S. aureus and are important subject of drug targeting. The appearance of antibiotic-resistant types of pathogenic S. aureus (e.g., methicillin-resistant S. aureus, MRSA) is a worldwide medical problem. In the present work, a novel lipase from a newly isolated MRSA strain from a cow with subclinical mastitis was cloned and biochemically characterized. The mature part of the lipase was expressed in Escherichia coli and purified by nickel affinity chromatography. It displays a high lipase activity at pH 8.0 and 25 °C using p-nitrophenyl palmitate and has a preference for medium-long-chain substrates of p-nitrophenyl esters (pNPC10-C16). Furthermore, in search of inhibitors, the effect of farnesol on the growth of S. aureus and the lipase activity was also studied. Farnesol inhibits the growth of S. aureus and is a mixed-type inhibitor with Ki and Ki (') values of 0.2 and 1.2 mmol L(-1), respectively. A lipase with known properties could not only serve as a template for developing inhibitors for S. aureus but also a valuable addition to enzyme toolbox of biocatalysis. The discovery of this lipase can be potentially important and could provide a new target for pharmaceutical intervention against S. aureus infection. PMID:25385356

  3. Significância clínica, epidemiologia e microbiologia das bacteremias por estafilococos coagulase-negativos em Hospital de Ensino

    Directory of Open Access Journals (Sweden)

    Góngora-Rubio F.

    1997-01-01

    Full Text Available Os estafilococos coagulase-negativos (ECN são importantes agentes etiológicos das bacteremias hospitalares e freqüentemente considerados como contaminantes de hemoculturas. No período de outubro de 1990 a setembro de 1992, foram estudadas 300 hemoculturas positivas para ECN no Hospital São Paulo, sendo 141 bacteremias consideradas de origem hospitalar. Com o objetivo de diferenciar as bacteremias hospitalares verdadeiras das contaminantes por ECN, foram definidos critérios clínicos e microbiológicos. Apenas 20,6% das bacteremias hospitalares por ECN foram consideradas como verdadeiras. A maior freqüência de recém-nascidos internados na unidade de terapia intensiva neonatal, a presença de cateter intravascular e a utilização de nutrição parenteral foram achados significativos. Não houve diferença significante quanto a resistência a oxacilina e produção de SLIME entre os ECN isolados das bacteremias verdadeiras e contaminantes. O critério clínico e a positividade da hemocultura até 48 horas após a incubação, utilizados em nossa definição, foram úteis para caracterizar as bacteremias verdadeiras por ECN.

  4. The adherens junctions control susceptibility to Staphylococcus aureus α-toxin.

    Science.gov (United States)

    Popov, Lauren M; Marceau, Caleb D; Starkl, Philipp M; Lumb, Jennifer H; Shah, Jimit; Guerrera, Diego; Cooper, Rachel L; Merakou, Christina; Bouley, Donna M; Meng, Wenxiang; Kiyonari, Hiroshi; Takeichi, Masatoshi; Galli, Stephen J; Bagnoli, Fabio; Citi, Sandra; Carette, Jan E; Amieva, Manuel R

    2015-11-17

    Staphylococcus aureus is both a transient skin colonizer and a formidable human pathogen, ranking among the leading causes of skin and soft tissue infections as well as severe pneumonia. The secreted bacterial α-toxin is essential for S. aureus virulence in these epithelial diseases. To discover host cellular factors required for α-toxin cytotoxicity, we conducted a genetic screen using mutagenized haploid human cells. Our screen identified a cytoplasmic member of the adherens junctions, plekstrin-homology domain containing protein 7 (PLEKHA7), as the second most significantly enriched gene after the known α-toxin receptor, a disintegrin and metalloprotease 10 (ADAM10). Here we report a new, unexpected role for PLEKHA7 and several components of cellular adherens junctions in controlling susceptibility to S. aureus α-toxin. We find that despite being injured by α-toxin pore formation, PLEKHA7 knockout cells recover after intoxication. By infecting PLEKHA7(-/-) mice with methicillin-resistant S. aureus USA300 LAC strain, we demonstrate that this junctional protein controls disease severity in both skin infection and lethal S. aureus pneumonia. Our results suggest that adherens junctions actively control cellular responses to a potent pore-forming bacterial toxin and identify PLEKHA7 as a potential nonessential host target to reduce S. aureus virulence during epithelial infections.

  5. Interleukin-33 facilitates neutrophil recruitment and bacterial clearance in S. aureus-caused peritonitis.

    Science.gov (United States)

    Lan, Fang; Yuan, Baohong; Liu, Tao; Luo, Xiaochun; Huang, Ping; Liu, Yunjun; Dai, Liangcheng; Yin, Hui

    2016-04-01

    Interleukin (IL)-33, a newly recognized member of IL-1 family of cytokines, plays an important role in polarizing Th2-associated immunity. Recently growing evidence indicates that IL-33 also represents a crucial mediator of antimicrobial infection. In this study, we investigated the effect of IL-33 on antibacterial response using an acute Staphylococcus aureus peritoneal infection model. Our results showed that IL-33 administration induced a rapid bacterial clearance and markedly reduced the S. aureus infection-related mortality. IL-33-treated mice displayed increased neutrophil influx into the focus of infection and higher concentrations of chemokine CXCL2 in the peritoneum than untreated mice. The beneficial effect of IL-33 priming was related to reversal of the S. aureus-induced reduction of CXCR2 expression on the surface of neutrophils. Furthermore, conditioning of neutrophils by IL-33 led to the enhancement of complement receptor 3 expression induced by S. aureus, which in turn facilitates the phagocytosis of opsonized S. aureus. Finally, neutrophils primed by IL-33 upregulated the production of reactive oxygen species and the subsequent killing activity for S. aureus. All together, these findings suggest that IL-33, through regulating multiple steps of neutrophil-mediated bactericidal function, provides a profound effect in host antimicrobial defense response.

  6. Buah Mengkudu (Morinda citrifolia Meningkatkan Respon Imun Mencit (Mus musculus Terhadap Infeksi Bakteri Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Mufidah Zumrotul

    2015-11-01

    Full Text Available Noni (Morinda citrifolia Increase Immune Response in Mice (Mus musculus Infected Staphylococcus aureus. Infection disease caused by bacteria is one of the illness in several developing countries including in Indonesia, with high mortality rate. Infection of  S. aureus as the cause of problem resistance for antibiotic or multi drug resistance are giving the therapy of drug itself with change to medical herbal. The aim of this study is known the role of M.citrifolia extract to increase immune response of mice with infectioned of S. aureus. Mice were divided into two groups there are Non Infection and infection. Non Infection is without S. aureus and than infection has S. aureus. The each groups are including control, dose 1 (25 mg/kg BW, dose 2 (100 mg/kg BW, and dose 3 (300 mg/kg BW. Relative number of lymphocyte T cell (CD4+ subsets was measured  using the BD FACSCaliburTM Flowcytometer. Data were analyzed using Analysis of Varians (p<0,05 and using SPSS 16 for windows. The result showed that administration of  M. citrifolia crude extract in non infection groups was significantly increase the relative amounts T cell subsets (CD4+. Noni fruit extract can used as prevention therapy on infection disease of S. aureus bacteria because it contains active compounds that are anti-inflammation

  7. XerC Contributes to Diverse Forms of Staphylococcus aureus Infection via agr-Dependent and agr-Independent Pathways.

    Science.gov (United States)

    Atwood, Danielle N; Beenken, Karen E; Loughran, Allister J; Meeker, Daniel G; Lantz, Tamara L; Graham, Justin W; Spencer, Horace J; Smeltzer, Mark S

    2016-04-01

    We demonstrate that mutation of xerC, which reportedly encodes a homologue of an Escherichia coli recombinase, limits biofilm formation in the methicillin-resistant Staphylococcus aureus strain LAC and the methicillin-sensitive strain UAMS-1. This was not due to the decreased production of the polysaccharide intracellular adhesin (PIA) in either strain because the amount of PIA was increased in a UAMS-1xerC mutant and undetectable in both LAC and its isogenic xerC mutant. Mutation of xerC also resulted in the increased production of extracellular proteases and nucleases in both LAC and UAMS-1, and limiting the production of either class of enzymes increased biofilm formation in the isogenic xerC mutants. More importantly, the limited capacity to form a biofilm was correlated with increased antibiotic susceptibility in both strains in the context of an established biofilm in vivo. Mutation of xerC also attenuated virulence in a murine bacteremia model, as assessed on the basis of the bacterial loads in internal organs and overall lethality. It also resulted in the decreased accumulation of alpha toxin and the increased accumulation of protein A. These findings suggest that xerC may impact the functional status of agr. This was confirmed by demonstrating the reduced accumulation of RNAIII and AgrA in LAC and UAMS-1xerC mutants. However, this cannot account for the biofilm-deficient phenotype of xerC mutants because mutation of agr did not limit biofilm formation in either strain. These results demonstrate that xerC contributes to biofilm-associated infections and acute bacteremia and that this is likely due to agr-independent and -dependent pathways, respectively.

  8. No specific time window distinguishes between community-, healthcare-, and hospital-acquired bacteremia, but they are prognostically robust

    DEFF Research Database (Denmark)

    Nielsen, Stig Lønberg; Pedersen, Court; Ostergaard, Christian;

    2014-01-01

    Objective. We examined whether specific time windows after hospital admission reflected a sharp transition between community and hospital acquisition of bacteremia. We further examined whether different time windows to distinguish between community acquisition, healthcare association (HCA...... mortality pertaining to bacteremia 0, 1, 2, …, 30, and 31 days and later after admission. Next, we assessed whether different admission (0-1, 0-2, 0-3, 0-7 days) and HCA (30, 90 days) time windows were associated with changes in odds ratio (OR) and area under the receiver operating characteristic (ROC......) curve for 30-day mortality, adjusting for sex, age, comorbidity, and microorganisms. Results. For 56,606 bacteremic episodes, no sharp transitions were detected on a specific day after admission. Among the 8 combined time windows, ORs for 30-day mortality varied from 1.30 (95% confidence interval [CI...

  9. Successful treatment of a neonate with persistent vancomycin-resistant enterococcal bacteremia with a daptomycin-containing regimen.

    Science.gov (United States)

    Beneri, Christy A; Nicolau, David P; Seiden, Howard S; Rubin, Lorry G

    2008-01-01

    Infections caused by vancomycin-resistant enterococci (VRE) may be difficult to treat because of the limited armamentarium of antimicrobial agents. The difficulty is compounded in pediatric patients in general and neonates in particular because many of the newer antimicrobials have not been studied or approved for children. We report a 3-week-old infant who developed enterococcal bacteremia on post-operative day 10 after a surgical palliation for complex congenital heart disease that was complicated by acute renal failure. Despite removal of vascular catheters and antimicrobial regimens that included linezolid, quinupristin/dalfopristin, ampicillin/sulbactam, rifampin, and gentamicin, bacteremia persisted. It was not cleared until daptomycin (in combination with doxycycline) was started. This is the first case of successful treatment of probable endocarditis due to VRE in a neonate using a daptomycin-containing regimen. PMID:21694874

  10. Genomic Analysis of Companion Rabbit Staphylococcus aureus.

    Science.gov (United States)

    Holmes, Mark A; Harrison, Ewan M; Fisher, Elizabeth A; Graham, Elizabeth M; Parkhill, Julian; Foster, Geoffrey; Paterson, Gavin K

    2016-01-01

    In addition to being an important human pathogen, Staphylococcus aureus is able to cause a variety of infections in numerous other host species. While the S. aureus strains causing infection in several of these hosts have been well characterised, this is not the case for companion rabbits (Oryctolagus cuniculus), where little data are available on S. aureus strains from this host. To address this deficiency we have performed antimicrobial susceptibility testing and genome sequencing on a collection of S. aureus isolates from companion rabbits. The findings show a diverse S. aureus population is able to cause infection in this host, and while antimicrobial resistance was uncommon, the isolates possess a range of known and putative virulence factors consistent with a diverse clinical presentation in companion rabbits including severe abscesses. We additionally show that companion rabbit isolates carry polymorphisms within dltB as described as underlying host-adaption of S. aureus to farmed rabbits. The availability of S. aureus genome sequences from companion rabbits provides an important aid to understanding the pathogenesis of disease in this host and in the clinical management and surveillance of these infections. PMID:26963381

  11. Increased mortality associated with meticillin-resistant Staphylococcus aureus (MRSA) infection in the intensive care unit: results from the EPIC II study

    NARCIS (Netherlands)

    Hanberger, H.; Walther, S.; Leone, M.; Barie, P.S.; Rello, J.; Lipman, J.; Marshall, J.C.; Anzueto, A.; Sakr, Y.; Pickkers, P.; Felleiter, P.; Engoren, M.; Vincent, J.L.

    2011-01-01

    Controversy continues regarding whether the presence of meticillin resistance increases mortality risk in Staphylococcus aureus infections. In this study, we assessed the role of meticillin resistance in survival of patients with S. aureus infection included in the EPIC II point-prevalence study of

  12. 21 CFR 866.3700 - Staphylococcus aureus serological reagents.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Staphylococcus aureus serological reagents. 866... Staphylococcus aureus serological reagents. (a) Identification. Staphylococcus aureus serological reagents are... epidemiological information on these diseases. Certain strains of Staphylococcus aureus produce an...

  13. Exfoliative Toxins of Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Michal Bukowski

    2010-05-01

    Full Text Available Staphylococcus aureus is an important pathogen of humans and livestock. It causes a diverse array of diseases, ranging from relatively harmless localized skin infections to life-threatening systemic conditions. Among multiple virulence factors, staphylococci secrete several exotoxins directly associated with particular disease symptoms. These include toxic shock syndrome toxin 1 (TSST-1, enterotoxins, and exfoliative toxins (ETs. The latter are particularly interesting as the sole agents responsible for staphylococcal scalded skin syndrome (SSSS, a disease predominantly affecting infants and characterized by the loss of superficial skin layers, dehydration, and secondary infections. The molecular basis of the clinical symptoms of SSSS is well understood. ETs are serine proteases with high substrate specificity, which selectively recognize and hydrolyze desmosomal proteins in the skin. The fascinating road leading to the discovery of ETs as the agents responsible for SSSS and the characterization of the molecular mechanism of their action, including recent advances in the field, are reviewed in this article.

  14. [Staphylococcus aureus and antibiotic resistance].

    Science.gov (United States)

    Sancak, Banu

    2011-07-01

    After the report of first case of methicillin-resistant Staphylococcus aureus (MRSA) in 1961, MRSA become a major problem worldwide. Over the last decade MRSA strains have emerged as serious pathogens in nosocomial and community settings. Glycopeptides (vancomycin and teicoplanin) are still the current mainstay of therapy for infections caused by MRSA. In the last decade dramatic changes have occurred in the epidemiology of MRSA infections. The isolates with reduced susceptibility and in vitro resistance to vancomycin have emerged. Recently, therapeutic alternatives such as quinupristin/dalfopristin, linezolid, tigecycline and daptomycin have been introduced into clinical practice for treating MRSA infections. Nevertheless, these drugs are only approved for certain indication and resistance has already been reported. In this review, the new information on novel drugs for treating MRSA infections and the resistance mechanisms of these drugs were discussed. PMID:21935792

  15. The Heme Sensor System of Staphylococcus aureus

    OpenAIRE

    Stauff, Devin L; Skaar, Eric P.

    2009-01-01

    The important human pathogen Staphylococcus aureus is able to satisfy its nutrient iron requirement by acquiring heme from host hemoglobin in the context of infection. However, heme acquisition exposes S. aureus to heme toxicity. In order to detect the presence of toxic levels of exogenous heme, S. aureus is able to sense heme through the heme sensing system (HssRS) two-component system. Upon sensing heme, HssRS directly regulates the expression of the heme-regulated ABC transporter HrtAB, wh...

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

    Science.gov (United States)

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

    2015-01-01

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

  17. The Association of Streptococcus gallolyticus Subspecies pasteurianus Bacteremia with the Detection of Premalignant and Malignant Colonic Lesions.

    Science.gov (United States)

    Chand, Gaurav; Shamban, Leonid; Forman, Adam; Sinha, Prabhat

    2016-01-01

    Streptococcus gallolyticus subspecies (subsp.) gallolyticus (formerly bovis biotype I) bacteremia has been associated with colonic adenocarcinoma. The bovis species underwent reclassification in 2003. Subtypes of gallolyticus are associated with colonic malignancy but are less frequent, resulting in less awareness. A 71-year-old male admitted with worsening lower back pain and fevers. Initial vital signs and laboratory data were within normal limits. MRI revealed lumbosacral osteomyelitis and antibiotics were initiated. Blood cultures showed Streptococcus species, prompting a transesophageal echocardiogram (TEE) revealing vegetations on the mitral and aortic valves. The etiology for his endocarditis was unclear. A colonoscopy was suggested, but his clinical instability made such a procedure intolerable. Final cultures revealed Streptococcus gallolyticus subsp. pasteurianus (previously bovis biotype II). After antibiotic completion he underwent aortic grafting with valve replacements. Later, he was readmitted for Streptococcus bacteremia. After a negative TEE, colonoscopy revealed a 2.5 × 3 cm cecal tubulovillous adenoma with high-grade dysplasia suspicious for his origin of infection. Clinicians understand the link between Streptococcus gallolyticus subsp. gallolyticus (bovis type I) and malignancy, but the new speciation may be unfamiliar. There are no guidelines for managing S. gallolyticus subsp. pasteurianus bacteremia; therefore a colonoscopy should be considered when no source is identified. PMID:27555973

  18. Infertility as a consequence of spermagglutinating Staphylococcus aureus colonization in genital tract of female mice.

    Directory of Open Access Journals (Sweden)

    Siftjit Kaur

    Full Text Available Various studies have shown Staphylococcus aureus to be one of the most prevalent organism in male and female genital tract but most practitioners dismiss it as mere contamination which is assumed to be of no significance. However, it is now suggested that the presence of this organism should not be ignored, as incubation of spermatozoa with S. aureus results in reduced sperm motility. Although S. aureus has been reported to cause immobilization of spermatozoa, however, its role in infertility has yet to be elucidated. The present study was designed to establish a spermagglutinating strain of S. aureus isolated from the cervix of a woman with unexplained infertility, in mouse and evaluate its effect on fertility outcome. Female Balb/c mice were inoculated intravaginally with different doses of S. aureus (10(4, 10(6 or 10(8cfu/20 µl for 10 consecutive days. Microbial colonization monitored every 3(rd day by vaginal cultures, revealed that strain could efficiently colonize mouse vagina. Mating on day 12, with proven breeder males led to 100% decrease in fertility as compared to control. Even a single dose of 10(6 or 10(8cfu could lead to vaginal colonization which persisted for 10 days followed by gradual clearing till 21 days, vaginal cultures were negative thereafter. Female mice mated on day 7 (culture positive, were rendered infertile, however, the mice mated on day 22 (culture negative, retained fertility and delivered pups indicating its role in provoking infertility. Further, except infertility, no other clinical manifestation could be seen apparently or histologically. However, when a non-spermagglutinating/immobilizing standard strain of S. aureus MTCC6625 was inoculated intravaginally at 10(8cfu for 10 days followed by mating on day 12, fertility was observed in all the female mice. This supports the hypothesis that infertility observed in the former groups was as a result of colonization with spermagglutinating strain of S. aureus.

  19. Laboratory Maintenance of Methicillin-Resistant Staphylococcus aureus (MRSA)

    OpenAIRE

    Nicholas P Vitko; Richardson, Anthony R.

    2013-01-01

    Staphylococcus aureus is an important bacterial pathogen in the hospital and community settings, especially Staphylococcus aureus clones that exhibit methicillin-resistance (MRSA). Many strains of S. aureus are utilized in the laboratory, underscoring the genetic differences inherent in clinical isolates. S. aureus grows quickly at 37°C with aeration in rich media (e.g. BHI) and exhibits a preference for glycolytic carbon sources. Furthermore, S. aureus has a gold pigmentation, exhibits β-hem...

  20. Mastite com lesões sistêmicas por Staphylococus aureus subesp. aureus em coelhos

    OpenAIRE

    Traverso Sandra Davi; Cunha Leonardo da; Fernandes Joaquim César Teixeira; Loretti Alexandre Paulino; Rhoden Adriana; Wunder Jr. Elsio; Driemeier David

    2003-01-01

    Em uma criação composta por 1800 coelhos, 33% das matrizes apresentaram mastite e lesões cutâneas crostosas e purulentas. Estes animais apresentavam-se entre 10 a- 12 meses de idade e em segunda parição. Quinze coelhos afetados foram sacrificados e necropsiados. Na necropsia, além das lesões cutâneas haviam microabscessos em diversos órgãos. Das amostras coletadas isolou-se Staphylococcus aureus subesp. aureus. S. aureus subesp. aureus também foi isolado de "swab" nasal coletado do tratador e...

  1. Mortality and Hospital Stay Associated with Resistant Staphylococcus aureus and Escherichia coli Bacteremia : Estimating the Burden of Antibiotic Resistance in Europe

    NARCIS (Netherlands)

    de Kraker, Marlieke E. A.; Davey, Peter G.; Grundmann, Hajo

    2011-01-01

    Background: The relative importance of human diseases is conventionally assessed by cause-specific mortality, morbidity, and economic impact. Current estimates for infections caused by antibiotic-resistant bacteria are not sufficiently supported by quantitative empirical data. This study determined

  2. Bacteremia in cirrhotic patients submitted to endoscopic band ligation of esophageal varices Bacteremia em pacientes cirróticos submetidos a ligadura elástica endoscópica de varizes esofágicas

    Directory of Open Access Journals (Sweden)

    Eduardo Balzano Maulaz

    2003-09-01

    Full Text Available BACKGROUND: Endoscopic procedures can develop bacteremia. Patients with chronic liver disease are more predisposed to undergo bacteremia and infections because they are immunocompromised. AIMS: The purpose of this study was to determine the incidence of bacteremia in cirrhotics submitted to endoscopic variceal ligation. METHODS: Three groups of 40 patients each were studied. One group was made up of patients with cirrhosis who were submitted to ligation, a second group was composed of cirrhotics who underwent esophagogastroduodenoscopy only, and a third group was composed of patients without liver disease who underwent esophagogastroduodenoscopy. Blood was sampled from all patients for culture, both in aerobic and in anaerobic mediums, immediately before endoscopy and at 5 and 30 minutes after its completion. RESULTS: Blood culture was positive in 6 samples. In 4 of these, the bacteria (Staphylococcus hominis hominis, Staphylococcus auricularis, Acinetobacter lwoffii, and coagulase-negative staphylococcus were isolated before the endoscopic procedure and thus were considered as contamination. In the ligation group, a streptococcus of the viridans group was isolated 5 minutes after the procedure, and in the cirrhosis without ligation group, a Staphylococcus epidermidis was isolated at 30 minutes. None of the patients showed clinical evidence of infection. CONCLUSIONS: The bacteremia incidence in cirrhotic patients submitted to variceal ligation was 2.5%, showing no difference from the control groups.RACIONAL: Os procedimentos endoscópicos são passíveis de favorecerem o desenvolvimento de bacteremia. Por serem imunodeprimidos, os hepatopatas crônicos estão mais predispostos a essa complicação e, conseqüentemente, a infecções. OBJETIVO: Determinar a incidência de bacteremia em pacientes cirróticos submetidos a ligadura elástica endoscópica de varizes esofágicas. PACIENTES E MÉTODOS: Foram estudados prospectivamente 120 pacientes

  3. Staphylococcus aureus nuclease is an SaeRS-dependent virulence factor.

    Science.gov (United States)

    Olson, Michael E; Nygaard, Tyler K; Ackermann, Laynez; Watkins, Robert L; Zurek, Oliwia W; Pallister, Kyler B; Griffith, Shannon; Kiedrowski, Megan R; Flack, Caralyn E; Kavanaugh, Jeffrey S; Kreiswirth, Barry N; Horswill, Alexander R; Voyich, Jovanka M

    2013-04-01

    Several prominent bacterial pathogens secrete nuclease (Nuc) enzymes that have an important role in combating the host immune response. Early studies of Staphylococcus aureus Nuc attributed its regulation to the agr quorum-sensing system. However, recent microarray data have indicated that nuc is under the control of the SaeRS two-component system, which is a major regulator of S. aureus virulence determinants. Here we report that the nuc gene is directly controlled by the SaeRS two-component system through reporter fusion, immunoblotting, Nuc activity measurements, promoter mapping, and binding studies, and additionally, we were unable identify a notable regulatory link to the agr system. The observed SaeRS-dependent regulation was conserved across a wide spectrum of representative S. aureus isolates. Moreover, with community-associated methicillin-resistant S. aureus (CA MRSA) in a mouse model of peritonitis, we observed in vivo expression of Nuc activity in an SaeRS-dependent manner and determined that Nuc is a virulence factor that is important for in vivo survival, confirming the enzyme's role as a contributor to invasive disease. Finally, natural polymorphisms were identified in the SaeRS proteins, one of which was linked to Nuc regulation in a CA MRSA USA300 endocarditis isolate. Altogether, our findings demonstrate that Nuc is an important S. aureus virulence factor and part of the SaeRS regulon.

  4. Staphylococcus aureus spa type t437

    DEFF Research Database (Denmark)

    Glasner, C; Pluister, G; Westh, H;

    2015-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) belonging to the multilocus sequence type clonal complex 59 (MLST CC59) is the predominant community-associated MRSA clone in Asia. This clone, which is primarily linked with the spa type t437, has so far only been reported in low numbers among...... large epidemiological studies in Europe. Nevertheless, the overall numbers identified in some Northern European reference laboratories have increased during the past decade. To determine whether the S. aureus t437 clone is present in other European countries, and to assess its genetic diversity across...... Europe, we analysed 147 S. aureus t437 isolates from 11 European countries collected over a period of 11 years using multiple locus variable number tandem repeat fingerprinting/analysis (MLVF/MLVA) and MLST. Additionally 16 S. aureus t437 isolates from healthy carriers and patients from China were...

  5. Relationship between time to positivity of blood culture with clinical characteristics and hospital mortality in patients with Escherichia coli bacteremia

    Institute of Scientific and Technical Information of China (English)

    BO Shi-ning; BO Jian; NING Yong-zhong; ZHAO Yu; LU Xiao-lin; YANG Ji-yong; ZHU Xi; YAO Gai-qi

    2011-01-01

    Background Previous studies indicated that the time to positivity (TTP) of blood culture is a parameter correlating with degree of the bacteremia and outcome in patients with bloodstream infections caused by Escherichia coli (E.co/i). The objective of this study was to further investigate the diagnostic and prognostic power of using TTP to predict E. coli bacteremia.Methods A retrospective cohort study at two university hospitals was conducted. We retrieved all the medical records of those with E. coli bloodstream infection according to the records generated by their microbiology departments.Univariate and multivariate analyses were applied to identify clinical factors correlating with fast bacterial growth and significant prognostic factors for hospital mortality.Results Medical records of 353 episodes of E. coli bacteremia diagnosed between January 1,2007 and December 31,2009 were retrieved in the investigation. Univariate analysis demonstrated that the TTP≤7 hours group is associated with higher incidence of active malignancies (41.7% vs. 27.2%, P=0.010), neutropenia (30% vs.14.3%, P=0.007), primary bacteremia (55.0% vs. 33.4%, P=0.002), and poorer outcome (hospital mortality 43.3% vs.11.9%, P=0.000) than the TTP >7 hours group. Multivariate analysis revealed that the significant predictors of hospital mortality, in rank order from high to low, were TTP (for TTP <7 hours, odds ratio (OR): 4.886; 95% confidence interval (CI): 2.572-9.283; P=0.000),neutropenia (OR: 2.800; 95% CI:1.428-5.490; P=0.003), comedication of steroids or immunosuppressive agents (OR:2.670; 95% CI: 0.971-7.342; P=0.057).Conclusions Incidence of malignancies, neutropenia and primary bacterernia correlates with fast bacterial growth in patients with E. coli bacteremia. The parameter of TTP has been identified as a variable of highest correlation to hospital mortality and therefore can be potentially utilized as a mortality prognostic marker.

  6. Signaling mechanism by the Staphylococcus aureus two-component system LytSR: role of acetyl phosphate in bypassing the cell membrane electrical potential sensor LytS [version 2; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Kevin Patel

    2016-03-01

    Full Text Available The two-component system LytSR has been linked to the signal transduction of cell membrane electrical potential perturbation and is involved in the adaptation of Staphylococcus aureus to cationic antimicrobial peptides. It consists of a membrane-bound histidine kinase, LytS, which belongs to the family of multiple transmembrane-spanning domains receptors, and a response regulator, LytR, which belongs to the novel family of non-helix-turn-helix DNA-binding domain proteins. LytR regulates the expression of cidABC and lrgAB operons, the gene products of which are involved in programmed cell death and lysis. In vivo studies have demonstrated involvement of two overlapping regulatory networks in regulating the lrgAB operon, both depending on LytR. One regulatory network responds to glucose metabolism and the other responds to changes in the cell membrane potential. Herein, we show that LytS has autokinase activity and can catalyze a fast phosphotransfer reaction, with 50% of its phosphoryl group lost within 1 minute of incubation with LytR. LytS has also phosphatase activity. Notably, LytR undergoes phosphorylation by acetyl phosphate at a rate that is 2-fold faster than the phosphorylation by LytS. This observation is significant in lieu of the in vivo observations that regulation of the lrgAB operon is LytR-dependent in the presence of excess glucose in the medium. The latter condition does not lead to perturbation of the cell membrane potential but rather to the accumulation of acetate in the cell. Our study provides insights into the molecular basis for regulation of lrgAB in a LytR-dependent manner under conditions that do not involve sensing by LytS.

  7. The Staphylococcus aureus “superbug”

    OpenAIRE

    FOSTER, TIMOTHY JAMES

    2004-01-01

    PUBLISHED There has been some debate about the disease-invoking potential of Staphylococcus aureus strains and whether invasive disease is associated with particularly virulent genotypes, or "superbugs." A study in this issue of the JCI describes the genotyping of a large collection of nonclinical, commensal S. aureus strains from healthy individuals in a Dutch population. Extensive study of their genetic relatedness by amplified restriction fragment typing and comparison with strains that...

  8. Transmissible mupirocin resistance in Staphylococcus aureus.

    OpenAIRE

    Rahman, M.; Noble, W. C.; Cookson, B

    1989-01-01

    The spread of two strains of Staphylococcus aureus with high level resistance to mupirocin is described. The resistance proved to be easily transferred to other S. aureus strains by filter mating experiments and on the skin of mice. No plasmid band corresponding to the resistance could be demonstrated by agarose gel electrophoresis or by caesium chloride gradient centrifugation but cleavage of 'chromosomal' DNA from resistant recipients showed bright bands of DNA absent from sensitive controls.

  9. Faecal carriage of Staphylococcus aureus in the hospital and community setting: a systematic review

    Directory of Open Access Journals (Sweden)

    Shantelle eClaassen-Weitz

    2016-05-01

    Full Text Available Background and rationale: Staphylococcus aureus faecal carriage has been identified as a potential source for nosocomial transmission and a risk factor for disease development. This systematic review determined the overall S. aureus (including methicillin susceptible and resistant S. aureus (MSSA and MRSA faecal carriage rates within the community and healthcare settings.Methodology: Peer-reviewed articles indexed in Medline, Scopus, Academic Search Premier, Africa-Wide Information, CINAHL, and Web of Science were identified using applicable and controlled vocabulary through to 11 November 2015. Eligible studies were ascertained by three independent reviewers. Random-effects meta-analyses of proportions were performed to determine S. aureus, MSSA and MRSA faecal carriage rates reported by eligible studies.Results: Twenty six studies were included in this review. The pooled estimates for S. aureus, MSSA and MRSA faecal carriage were 26 % (95 % confidence interval (CI: 16.8 % - 36.3 %, 86 % (95 % confidence interval (CI: 65.9 % - 97.9 % and 10 % (95 % CI: 0.7 % - 27.0 %, respectively. Faecal S. aureus carriage rates increased on average from 10 % to 65 % during the first eight weeks of life, followed by an average carriage rate of 64 % at six months and 46 % at one year of life. Genotyping techniques were employed mainly in studies conducted in developed countries and comprised largely of gel-based techniques. Six studies reported on the role of S. aureus faecal strains in diarrhoea (n = 2 and the risk for acquiring infections (n = 4. Eight of the 26 studies included in this review performed antibiotic susceptibility testing of S. aureus faecal isolates.Conclusion: This study provides evidence that screening for S. aureus faecal carriage, at least in populations at high risk, could be an effective measure for the prevention of S. aureus transmission and infection in the healthcare and community setting. More well-structured studies need to be

  10. Serum procalcitonin: Early detection of neonatal bacteremia and septicemia in a tertiary healthcare facility

    Directory of Open Access Journals (Sweden)

    Ibeh Isaiah Nnanna

    2011-01-01

    Full Text Available Background: The benefits of procalcitonin measurement in neonatal bacteremia/septicemia with suspected nosocomial infection are unclear and unresearched. Aim: The aim of the study was to assess procalcitonin value as an early or first line diagnosis/prognosis for bacterial neonatal septicemic infection in selected critically ill neonates. Patients and Methods: An observational cohort study in a 10-bed intensive care unit was performed. Sixty neonates, with either proven or clinically suspected, but not confirmed, bacterial neonatal septicemic infection were included. Procalcitonin measurements were obtained on the day when the infection was suspected. Neonates with proven septicemic infection were compared to those without. The diagnostic value of procalcitonin was determined through the area under the corresponding receiver operating characteristic curve (AUROCC. In addition, the predictive value of procalcitonin variations preceding the clinical suspicion of infection was also assessed. Results: Procalcitonin was the best early predictor of proven infection in this population of neonates with a clinical suspicion of septicemia (AUROCC = 0.80; 91.6% CI, 0.68-0.91. In contrast, CRP elevation, leukocyte count and fever had a poor predictive value in our population. Conclusion: PCT monitoring could be helpful in the early diagnosis of neonatal septicemic infection in the intensive care unit. Both absolute values and variations should be considered and evaluated in further studies.

  11. Serum procalcitonin: Early detection of neonatal bacteremia and septicemia in a tertiary healthcare facility

    Directory of Open Access Journals (Sweden)

    Ibeh Isaiah Nnanna

    2011-03-01

    Full Text Available Background: The benefits of procalcitonin measurement in neonatal bacteremia/septicemia with suspected nosocomial infection are unclear and unresearched. Aim: The aim of the study was to assess procalcitonin value as an early or first line diagnosis/prognosis for bacterial neonatal septicemic infection in selected critically ill neonates. Patients and Methods: An observational cohort study in a 10-bed intensive care unit was performed. Sixty neonates, with either proven or clinically suspected, but not confirmed, bacterial neonatal septicemic infection were included. Procalcitonin measurements were obtained on the day when the infection was suspected. Neonates with proven septicemic infection were compared to those without. The diagnostic value of procalcitonin was determined through the area under the corresponding receiver operating characteristic curve (AUROCC. In addition, the predictive value of procalcitonin variations preceding the clinical suspicion of infection was also assessed. Results: Procalcitonin was the best early predictor of proven infection in this population of neonates with a clinical suspicion of septicemia (AUROCC = 0.80; 91.6% CI, 0.68–0.91. In contrast, CRP elevation, leukocyte count and fever had a poor predictive value in our population. Conclusion: PCT monitoring could be helpful in the early diagnosis of neonatal septicemic infection in the intensive care unit. Both absolute values and variations should be considered and evaluated in further studies.

  12. August 2014 Tucson critical care journal club: bacteremia in cardiac arrest

    Directory of Open Access Journals (Sweden)

    Hypes C

    2014-10-01

    Full Text Available No abstract available. Article truncated at 150 words. Out-of-hospital cardiac arrest (OHCA is an uncommon, but important, condition encountered in the emergency department (ED. While cardiac arrest represents the final common pathway of multiple conditions, early evaluation often focuses on cardiac abnormalities. However, observed associations between infection, particularly pneumonia, and in-hospital cardiac arrest led Coba et al. (1 to investigate the incidence of bacteremia among OHCA patients. The study prospectively investigated 250 adult patients who presented to an academic ED with OHCA between 2007 and 2009. Two blood culture samples were drawn during resuscitation or shortly after return of spontaneous circulation through vascular devices placed for clinical purposes. Children, pregnant women, victims of trauma were excluded. To minimize false positive results, patients were classified as bacteremic if one sample was positive for a typical pathogen or both samples were positive for the same skin colonizing organism. Patients in whom only 1 sample was positive for suspected skin contaminant ...

  13. Bacteremia due to anaerobic bacteria: epidemiology in a northern Bari Hospital, Italy

    Directory of Open Access Journals (Sweden)

    Maria Antonietta Distasi

    2015-06-01

    Full Text Available Background. Anaerobic bacteria are part of the commensal bacterial flora of skin and mucosae. Iatrogenic and pathological conditions altering this commensal relationship cause life-threatening diseases. Materials and Methods. We analysed the blood cultures sent to the microbiology of our hospital between 2008 and the first quarter of 2013 to measure the frequency of bacteraemia caused by anaerobia. We examined 3138 vials of blood cultures for anaerobia, inoculated following in-house standard procedures. The colonies grown in absence of air were subjected to biochemical analysis. The MICs of metronidazole for 23 of the 26 organisms was tested. Results. Twelve bacteria of the Bacteroides genus were identified, 9 Propionibacterium acnes, 1 Peptosctreptococcus micros, 1 Lactobacillus acidophilus, 1 Clostridium perfringens, 1 Prevotella oralis, 1 Eubacterium lentum. Conclusions. The analysis of the results suggests that the incidence of cultures positive to anaerobia was constant across the years. We note that advanced age, altered mucocutaneous tropism, alterations to the oral and intestinal bacterial flora intensify the risk of anaerobial pathogenicity. The analysis of the metronidazole-determined MIC suggests that the intestinal anaerobic flora responds well to therapy and prophylaxis with Metronidazole, while the anaerobic bacteria residing on skin and other mucosae are resistant. It is however hard to determine the clinical impact of anaerobic bacteremiae and their effect on the outcome of the patient, due to the scarcity of available clinical data.

  14. Comparative Genomic Analysis of Meningitis- and Bacteremia-Causing Pneumococci Identifies a Common Core Genome.

    Science.gov (United States)

    Kulohoma, Benard W; Cornick, Jennifer E; Chaguza, Chrispin; Yalcin, Feyruz; Harris, Simon R; Gray, Katherine J; Kiran, Anmol M; Molyneux, Elizabeth; French, Neil; Parkhill, Julian; Faragher, Brian E; Everett, Dean B; Bentley, Stephen D; Heyderman, Robert S

    2015-10-01

    Streptococcus pneumoniae is a nasopharyngeal commensal that occasionally invades normally sterile sites to cause bloodstream infection and meningitis. Although the pneumococcal population structure and evolutionary genetics are well defined, it is not clear whether pneumococci that cause meningitis are genetically distinct from those that do not. Here, we used whole-genome sequencing of 140 isolates of S. pneumoniae recovered from bloodstream infection (n = 70) and meningitis (n = 70) to compare their genetic contents. By fitting a double-exponential decaying-function model, we show that these isolates share a core of 1,427 genes (95% confidence interval [CI], 1,425 to 1,435 genes) and that there is no difference in the core genome or accessory gene content from these disease manifestations. Gene presence/absence alone therefore does not explain the virulence behavior of pneumococci that reach the meninges. Our analysis, however, supports the requirement of a range of previously described virulence factors and vaccine candidates for both meningitis- and bacteremia-causing pneumococci. This high-resolution view suggests that, despite considerable competency for genetic exchange, all pneumococci are under considerable pressure to retain key components advantageous for colonization and transmission and that these components are essential for access to and survival in sterile sites.

  15. Comparative Genomic Analysis of Meningitis- and Bacteremia-Causing Pneumococci Identifies a Common Core Genome.

    Science.gov (United States)

    Kulohoma, Benard W; Cornick, Jennifer E; Chaguza, Chrispin; Yalcin, Feyruz; Harris, Simon R; Gray, Katherine J; Kiran, Anmol M; Molyneux, Elizabeth; French, Neil; Parkhill, Julian; Faragher, Brian E; Everett, Dean B; Bentley, Stephen D; Heyderman, Robert S

    2015-10-01

    Streptococcus pneumoniae is a nasopharyngeal commensal that occasionally invades normally sterile sites to cause bloodstream infection and meningitis. Although the pneumococcal population structure and evolutionary genetics are well defined, it is not clear whether pneumococci that cause meningitis are genetically distinct from those that do not. Here, we used whole-genome sequencing of 140 isolates of S. pneumoniae recovered from bloodstream infection (n = 70) and meningitis (n = 70) to compare their genetic contents. By fitting a double-exponential decaying-function model, we show that these isolates share a core of 1,427 genes (95% confidence interval [CI], 1,425 to 1,435 genes) and that there is no difference in the core genome or accessory gene content from these disease manifestations. Gene presence/absence alone therefore does not explain the virulence behavior of pneumococci that reach the meninges. Our analysis, however, supports the requirement of a range of previously described virulence factors and vaccine candidates for both meningitis- and bacteremia-causing pneumococci. This high-resolution view suggests that, despite considerable competency for genetic exchange, all pneumococci are under considerable pressure to retain key components advantageous for colonization and transmission and that these components are essential for access to and survival in sterile sites. PMID:26259813

  16. Carotenoid Formation by Staphylococcus aureus

    Science.gov (United States)

    Hammond, Ray K.; White, David C.

    1970-01-01

    The carotenoid pigments of Staphylococcus aureus U-71 were identified as phytoene; ζ-carotene; δ-carotene; phytofluenol; a phytofluenol-like carotenoid, rubixanthin; and three rubixanthin-like carotenoids after extraction, saponification, chromatographic separation, and determination of their absorption spectra. There was no evidence of carotenoid esters or glycoside ethers in the extract before saponification. During the aerobic growth cycle the total carotenoids increased from 45 to 1,000 nmoles per g (dry weight), with the greatest increases in the polar, hydroxylated carotenoids. During the anaerobic growth cycle, the total carotenoids increased from 20 nmoles per g (dry weight) to 80 nmoles per g (dry weight), and only traces of the polar carotenoids were formed. Light had no effect on carotenoid synthesis. About 0.14% of the mevalonate-2-14C added to the culture was incorporated into the carotenoids during each bacterial doubling. The total carotenoids did not lose radioactivity when grown in the absence of 14C for 2.5 bacterial doublings. The total carotenoids did not lose radioactivity when grown in the absence of 14C for 2.5 bacterial doublings. The incorporation and turnover of 14C indicated the carotenes were sequentially desaturated and hydroxylated to form the polar carotenoids. PMID:5423369

  17. Complete Genome Sequence of the Quality Control Strain Staphylococcus aureus subsp. aureus ATCC 25923.

    Science.gov (United States)

    Treangen, Todd J; Maybank, Rosslyn A; Enke, Sana; Friss, Mary Beth; Diviak, Lynn F; Karaolis, David K R; Koren, Sergey; Ondov, Brian; Phillippy, Adam M; Bergman, Nicholas H; Rosovitz, M J

    2014-01-01

    Staphylococcus aureus subsp. aureus ATCC 25923 is commonly used as a control strain for susceptibility testing to antibiotics and as a quality control strain for commercial products. We present the completed genome sequence for the strain, consisting of the chromosome and a 27.5-kb plasmid. PMID:25377701

  18. Complete Genome Sequence of the Quality Control Strain Staphylococcus aureus subsp. aureus ATCC 25923

    OpenAIRE

    Todd J. Treangen; Maybank, Rosslyn A.; Enke, Sana; Friss, Mary Beth; Diviak, Lynn F.; Karaolis, David K. R.; Koren, Sergey; Ondov, Brian; Phillippy, Adam M.; Bergman, Nicholas H.; Rosovitz, M. J.

    2014-01-01

    Staphylococcus aureus subsp. aureus ATCC 25923 is commonly used as a control strain for susceptibility testing to antibiotics and as a quality control strain for commercial products. We present the completed genome sequence for the strain, consisting of the chromosome and a 27.5-kb plasmid.

  19. Are gym surfaces reservoirs for Staphylococcus aureus? A point prevalence survey.

    Science.gov (United States)

    Markley, John Daniel; Edmond, Michael B; Major, Yvette; Bearman, Gonzalo; Stevens, Michael P

    2012-12-01

    We sought to identify staphylococcal contamination of gymnasium surfaces. Various environmental surfaces were cultured at a university fitness center. Ten out of 99 samples yielded Staphylococcus aureus, all of which were methicillin-susceptible. Gym surfaces may be colonized with staphylococci and could play a role in community transmission of staphylococcal species.

  20. Environmental meticillin-resistant Staphylococcus aureus (MRSA) disinfection using dry-mist-generated hydrogen peroxide

    DEFF Research Database (Denmark)

    Bartels, M.D.; Kristoffersen, K.; Slotsbjerg, T.;

    2008-01-01

    Meticillin-resistant Staphylococcus aureus (MRSA) is a major problem in hospitals worldwide. Hand hygiene is recognised as crucial in limiting the spread of MRSA but less is known about the role of MRSA reservoirs in the inanimate hospital environment. We evaluated the effect of hydrogen peroxide...

  1. Staphylococcus aureus nasal colonization in HIV-seropositive and HIV-seronegative drug users

    NARCIS (Netherlands)

    K.A. Holbrook; R.S. Klein; D. Hartel; D.A. Elliott; T. B. Barsky; L. H. Rothschild; F. D. Lowy

    1997-01-01

    textabstractNasal colonization plays an important role in the pathogenesis of Staphylococcus aureus infections. To identify characteristics associated with colonization, we studied a cross-section of a well-described cohort of HIV-seropositive and -seronegative active and former drug users considere

  2. In vitro phagocytosis of methicillin resistant and methicillin sensitive staphylococcus aureus by human polymorphonuclear leucocytes

    International Nuclear Information System (INIS)

    Staphylococcus aureus is a gram positive bacterium that causes a number of diseases such as abscesses, infective endocarditis, septic arthritis, etc. It is acquiring resistance against many antibiotics like methicillin; therefore its control is becoming increasingly difficult. Peripheral blood phagocytes particularly polymorphonuclear leucocytes play an important role in the protective mechanisms against these organisms. Phagocytes interact with bacteria and phagocytose these microorganisms to kill them. Phenotypically different isolates of Staphylococcus aureus including methicillin resistant Staphylococcus aureus (MRSA) and methicillin sensitive Staphylococcus aureus (MSSA) were collected from various hospitals of Lahore, Pakistan. Fresh polymorphonuclaer leucocytes were obtained from healthy individuals by centrifugation using Ficol-Hypaque gradient combined with dextran sedimentation. Microbiological method was used for the determination of phagocytic index of phenotypic variants of Staphylococcus aureus. A significant difference was observed between the phagocytic index of both bacterial groups. MSSA group showed the Mean+-SD of 79.46%+-3.9 while MRSA group showed 72.35%+-2.5. Significant difference in phagocytic index indicates that it can be one of the mechanisms of MRSA to evade host immune system as compare to MSSA. (author)

  3. Staphylokinase Control of Staphylococcus aureus Biofilm Formation and Detachment Through Host Plasminogen Activation.

    Science.gov (United States)

    Kwiecinski, Jakub; Peetermans, Marijke; Liesenborghs, Laurens; Na, Manli; Björnsdottir, Halla; Zhu, Xuefeng; Jacobsson, Gunnar; Johansson, Bengt R; Geoghegan, Joan A; Foster, Timothy J; Josefsson, Elisabet; Bylund, Johan; Verhamme, Peter; Jin, Tao

    2016-01-01

    Staphylococcus aureus biofilms, a leading cause of persistent infections, are highly resistant to immune defenses and antimicrobial therapies. In the present study, we investigated the contribution of fibrin and staphylokinase (Sak) to biofilm formation. In both clinical S. aureus isolates and laboratory strains, high Sak-producing strains formed less biofilm than strains that lacked Sak, suggesting that Sak prevents biofilm formation. In addition, Sak induced detachment of mature biofilms. This effect depended on plasminogen activation by Sak. Host-derived fibrin, the main substrate cleaved by Sak-activated plasminogen, was a major component of biofilm matrix, and dissolution of this fibrin scaffold greatly increased susceptibility of biofilms to antibiotics and neutrophil phagocytosis. Sak also attenuated biofilm-associated catheter infections in mouse models. In conclusion, our results reveal a novel role for Sak-induced plasminogen activation that prevents S. aureus biofilm formation and induces detachment of existing biofilms through proteolytic cleavage of biofilm matrix components.

  4. Coagulase gene polymorphisms detected by PCR in Staphylococcus aureus isolated from subclinical bovine mastitis in Turkey.

    Science.gov (United States)

    Karahan, Murat; Cetinkaya, Burhan

    2007-09-01

    The genetic relatedness of coagulase (coa) positive Staphylococcus aureus isolated from cows with subclinical mastitis in Turkey was investigated by polymerase chain reaction (PCR)-based restriction fragment length polymorphism (RFLP) analysis. Among 700 milk samples positive in the California Mastitis Test (CMT), species specific PCR identified 200 (28.6%) isolates as S. aureus and 161 (80.5%) of these isolates were positive for the 3' end of the coa gene by PCR. Most isolates (n=135, 83.9%) produced a single band on coa PCR, with molecular sizes ranging from 500 to 1400bp, whereas a small number of isolates (n=26, 16.1%) yielded two amplification products. Coa RFLP analysis using AluI and Hin6I revealed 23 and 22 band patterns, respectively. The detection of double bands by coa PCR, previously reported in human isolates, suggests that milking personnel can play a role in the transmission of S. aureus. PMID:16901735

  5. Combinatorial approaches with selected phytochemicals to increase antibiotic efficacy against Staphylococcus aureus biofilms.

    Science.gov (United States)

    Abreu, Ana Cristina; Saavedra, Maria José; Simões, Lúcia C; Simões, Manuel

    2016-10-01

    Combinations of selected phytochemicals (reserpine, pyrrolidine, quinine, morin and quercetin) with antibiotics (ciprofloxacin, tetracycline and erythromycin) were tested on the prevention and control of Staphylococcus aureus biofilms. The phytochemicals were also studied for their ability to avoid antibiotic adaptation and to inhibit antibiotic efflux pumps. Morin, pyrrolidine and quercetin at subinhibitory concentrations had significant effects in biofilm prevention and/or control when applied alone and combined with antibiotics. Synergism between antibiotics and phytochemicals was found especially against biofilms of NorA overexpressing strain S. aureus SA1199B. This strain when growing with subinhibitory concentrations of ciprofloxacin developed increased tolerance to this antibiotic. However, this was successfully reversed by quinine and morin. In addition, reserpine and quercetin showed significant efflux pump inhibition. The overall results demonstrate the role of phytochemicals in co-therapies to promote more efficient treatments and decrease antimicrobial resistance to antibiotics, with substantial effects against S. aureus in both planktonic and biofilm states. PMID:27643487

  6. Staphylococcus aureus autoinducer-2 quorum sensing decreases biofilm formation in an icaR-dependent manner

    Directory of Open Access Journals (Sweden)

    Yu Dan

    2012-12-01

    Full Text Available Abstract Background Staphylococcus aureus is an important pathogen that causes biofilm-associated infection in humans. Autoinducer 2 (AI-2, a quorum-sensing (QS signal for interspecies communication, has a wide range of regulatory functions in both Gram-positive and Gram-negative bacteria, but its exact role in biofilm formation in S. aureus remains unclear. Results Here we demonstrate that mutation of the AI-2 synthase gene luxS in S. aureus RN6390B results in increased biofilm formation compared with the wild-type (WT strain under static, flowing and anaerobic conditions and in a mouse model. Addition of the chemically synthesized AI-2 precursor in the luxS mutation strain (ΔluxS restored the WT phenotype. Real-time RT-PCR analysis showed that AI-2 activated the transcription of icaR, a repressor of the ica operon, and subsequently a decreased level of icaA transcription, which was presumably the main reason why luxS mutation influences biofilm formation. Furthermore, we compared the roles of the agr-mediated QS system and the LuxS/AI-2 QS system in the regulation of biofilm formation using the ΔluxS strain, RN6911 and the Δagr ΔluxS strain. Our data indicate a cumulative effect of the two QS systems on the regulation of biofilm formation in S. aureus. Conclusion These findings demonstrate that AI-2 can decrease biofilm formation in S. aureus via an icaR-activation pathway. This study may provide clues for therapy in S. aureus biofilm-associated infection.

  7. Panton-Valentine Leukocidin (PVL)-Positive Health Care-Associated Methicillin-Resistant Staphylococcus aureus Isolates Are Associated with Skin and Soft Tissue Infections and Colonized Mainly by Infective PVL-Encoding Bacteriophages

    Science.gov (United States)

    Hu, Qiwen; Cheng, Hang; Yuan, Wenchang; Zeng, Fangyin; Shang, Weilong; Tang, Dahai; Xue, Wencheng; Fu, Jianfeng; Zhou, Renjie; Zhu, Junmin; Yang, Jie; Hu, Zhen; Yuan, Jizhen; Zhang, Xia; Rao, Qing; Li, Shu; Chen, Zhijin; Hu, Xiaomei; Wu, Xingan

    2014-01-01

    The emergence of Panton-Valentine leukocidin (PVL)-positive methicillin-resistant Staphylococcus aureus (MRSA) is a public health concern worldwide. PVL is associated with community-associated MRSA and is linked to skin and soft tissue infections (SSTIs). However, PVL genes have also been detected in health care-associated (HA) MRSA isolates. The diseases associated with PVL-positive HA-MRSA isolates and the distributions of PVL-encoding bacteriophages in HA-MRSA have not been determined. In this study, a total of 259 HA-MRSA strains isolated between 2009 and 2012 in China from inpatients with SSTIs, pneumonia, and bacteremia were selected for molecular typing, including staphylococcal cassette chromosome mec typing, multilocus sequence typing, and staphylococcal protein A gene typing. The PVL genes and PVL bacteriophages in the MRSA isolates were characterized by PCR. Among the tested MRSA isolates, 28.6% (74/259) were PVL positive. The high prevalence of PVL-carrying HA-MRSA was observed to be associated with SSTIs but not with pneumonia or bacteremia. The PVL-positive HA-MRSA isolates were colonized mainly by infective PVL phages, namely, Φ7247PVL, ΦSLT, and ΦSa2958. The distribution of PVL-carrying bacteriophages differed geographically. Our study highlights the potential risk of the emergence of multidrug-resistant HA-MRSA strains with increased virulence. PMID:25339405

  8. Chlorhexidine-based antiseptic solutions effectively reduce catheter-related bacteremia.

    Science.gov (United States)

    Onder, Ali Mirza; Chandar, Jayanthi; Billings, Anthony; Diaz, Rosa; Francoeur, Denise; Abitbol, Carolyn; Zilleruelo, Gaston

    2009-09-01

    The aim of this retrospective study was to investigate if the application of chlorhexidine-based solutions (ChloraPrep) to the exit site and the hub of long-term hemodialysis catheters could prevent catheter-related bacteremia (CRB) and prolong catheter survival when compared with povidone-iodine solutions. There were 20,784 catheter days observed. Povidone-iodine solutions (Betadine) were used in the first half of the study and ChloraPrep was used in the second half for all the patients. Both groups received chlorhexidine-impregnated dressings at the exit sites. The use of ChloraPrep significantly decreased the incidence of CRB (1.0 vs 2.2/1,000 catheter days, respectively, P = 0.0415), and hospitalization due to CRB (1.8 days vs 4.1 days/1,000 catheter days, respectively, P = 0.0416). The incidence of exit site infection was similar for the two groups. Both the period of overall catheter survival (207.6 days vs 161.1 days, P = 0.0535) and that of infection-free catheter survival (122.0 days vs 106.9 days, P = 0.1100) tended to be longer for the catheters cleansed with ChloraPrep, with no statistical significance. In conclusion, chlorhexidine-based solutions are more effective for the prevention of CRB than povidone-iodine solutions. This positive impact cannot be explained by decreased number of exit site infections. This study supports the notion that the catheter hub is the entry site for CRB. PMID:19296135

  9. Multicenter Retrospective Study of Cefmetazole and Flomoxef for Treatment of Extended-Spectrum-β-Lactamase-Producing Escherichia coli Bacteremia

    Science.gov (United States)

    Yamamoto, Masaki; Nagao, Miki; Komori, Toshiaki; Fujita, Naohisa; Hayashi, Akihiko; Shimizu, Tsunehiro; Watanabe, Harumi; Doi, Shoichi; Tanaka, Michio; Takakura, Shunji; Ichiyama, Satoshi

    2015-01-01

    The efficacy of cefmetazole and flomoxef (CF) for the treatment of patients with extended-spectrum β-lactamase-producing Escherichia coli (ESBL-EC) bacteremia (ESBL-CF group) was compared with that of carbapenem treatment for ESBL-EC patients (ESBL-carbapenem group) and with that of CF treatment in patients with non-ESBL-EC bacteremia (non-ESBL-CF group). Adult patients treated for E. coli bacteremia in four hospitals were retrospectively evaluated. The 30-day mortality rates in patients belonging to the ESBL-CF, ESBL-carbapenem, and non-ESBL-CF groups were compared as 2 (empirical and definitive therapy) cohorts. The adjusted hazard ratios (aHRs) for mortality were calculated using Cox regression models with weighting according to the inverse probability of propensity scores for receiving CF or carbapenem treatment. The empirical-therapy cohort included 104 patients (ESBL-CF, 26; ESBL-carbapenem, 45; non-ESBL-CF, 33), and the definitive-therapy cohort included 133 patients (ESBL-CF, 59; ESBL-carbapenem, 54; non-ESBL-CF, 20). The crude 30-day mortality rates for patients in the ESBL-CF, ESBL-carbapenem, and non-ESBL-CF groups were, respectively, 7.7%, 8.9%, and 3.0% in the empirical-therapy cohort and 5.1%, 9.3%, and 5.0% in the definitve-therapy cohort. In patients without hematological malignancy and neutropenia, CF treatment for ESBL-EC patients was not associated with mortality compared with carbapenem treatment (empirical-therapy cohort: aHR, 0.87; 95% confidence interval [CI], 0.11 to 6.52; definitive therapy cohort: aHR, 1.04; CI, 0.24 to 4.49). CF therapy may represent an effective alternative to carbapenem treatment for patients with ESBL-EC bacteremia for empirical and definitive therapy in adult patients who do not have hematological malignancy and neutropenia. PMID:26100708

  10. Differing Burden and Epidemiology of Non-Typhi Salmonella Bacteremia in Rural and Urban Kenya, 2006–2009

    OpenAIRE

    Collins Tabu; Breiman, Robert F.; Benjamin Ochieng; Barrack Aura; Leonard Cosmas; Allan Audi; Beatrice Olack; Godfrey Bigogo; Juliette R Ongus; Patricia Fields; Eric Mintz; Deron Burton; Joe Oundo; Feikin, Daniel R.

    2012-01-01

    BACKGROUND: The epidemiology of non-Typhi Salmonella (NTS) bacteremia in Africa will likely evolve as potential co-factors, such as HIV, malaria, and urbanization, also change. METHODS: As part of population-based surveillance among 55,000 persons in malaria-endemic, rural and malaria-nonendemic, urban Kenya from 2006-2009, blood cultures were obtained from patients presenting to referral clinics with fever ≥38.0°C or severe acute respiratory infection. Incidence rates were adjusted based on ...

  11. Impact of Empiric Antimicrobial Therapy on Outcomes in Patients with Escherichia coli and Klebsiella pneumoniae Bacteremia: A Cohort Study

    Directory of Open Access Journals (Sweden)

    Furuno Jon P

    2008-09-01

    Full Text Available Abstract Background It is unclear whether appropriate empiric antimicrobial therapy improves outcomes in patients with bacteremia due to Escherichia coli or Klebsiella. The objective of this study is to assess the impact of appropriate empiric antimicrobial therapy on in-hospital mortality and post-infection length of stay in patients with Escherichia coli or Klebsiella bacteremia while adjusting for important confounding variables. Methods We performed a retrospective cohort study of adult patients with a positive blood culture for E. coli or Klebsiella between January 1, 2001 and June 8, 2005 and compared in-hospital mortality and post-infection length of stay between subjects who received appropriate and inappropriate empiric antimicrobial therapy. Empiric therapy was defined as the receipt of an antimicrobial agent between 8 hours before and 24 hours after the index blood culture was drawn and was considered appropriate if it included antimicrobials to which the specific isolate displayed in vitro susceptibility. Data were collected electronically and through chart review. Survival analysis was used to statistically assess the association between empiric antimicrobial therapy and outcome (mortality or length of stay. Multivariable Cox proportional hazards models were used to calculate hazard ratios (HR and 95% confidence intervals (CI. Results Among 416 episodes of bacteremia, 305 (73.3% patients received appropriate empiric antimicrobial therapy. Seventy-one (17% patients died before discharge from the hospital. The receipt of appropriate antimicrobial agents was more common in hospital survivors than in those who died (p = 0.04. After controlling for confounding variables, there was no association between the receipt of appropriate empiric antimicrobial therapy and in-hospital mortality (HR, 1.03; 95% CI, 0.60 to 1.78. The median post-infection length of stay was 7 days. The receipt of appropriate antimicrobial agents was not associated

  12. Differing Burden and Epidemiology of Non-Typhi Salmonella Bacteremia in Rural and Urban Kenya, 2006–2009

    OpenAIRE

    Tabu, Collins; Breiman, Robert F.; Ochieng, Benjamin; Aura, Barrack; Cosmas, Leonard; Audi, Allan; Olack, Beatrice; Bigogo, Godfrey; Ongus, Juliette R.; Fields, Patricia; Mintz, Eric; Burton, Deron; Oundo, Joe; Feikin, Daniel R.

    2012-01-01

    Background The epidemiology of non-Typhi Salmonella (NTS) bacteremia in Africa will likely evolve as potential co-factors, such as HIV, malaria, and urbanization, also change. Methods As part of population-based surveillance among 55,000 persons in malaria-endemic, rural and malaria-nonendemic, urban Kenya from 2006–2009, blood cultures were obtained from patients presenting to referral clinics with fever ≥38.0°C or severe acute respiratory infection. Incidence rates were adjusted based on pe...

  13. Genomics of Natural Populations of Staphylococcus aureus.

    Science.gov (United States)

    Fitzgerald, J Ross; Holden, Matthew T G

    2016-09-01

    Staphylococcus aureus is a major human pathogen and an important cause of livestock infections. The first S. aureus genomes to be published, 15 years ago, provided the first view of genome structure and gene content. Since then, thousands of genomes from a wide array of strains from different sources have been sequenced. Comparison of these sequences has resulted in broad insights into population structure, bacterial evolution, clone emergence and expansion, and the molecular basis of niche adaptation. Furthermore, this information is now being applied clinically in outbreak investigations to inform infection control measures and to determine appropriate treatment regimens. In this review, we summarize some of the broad insights into S. aureus biology gained from the analysis of genomes and discuss future directions and opportunities in this dynamic field of research. PMID:27482738

  14. Genomics of Natural Populations of Staphylococcus aureus.

    Science.gov (United States)

    Fitzgerald, J Ross; Holden, Matthew T G

    2016-09-01

    Staphylococcus aureus is a major human pathogen and an important cause of livestock infections. The first S. aureus genomes to be published, 15 years ago, provided the first view of genome structure and gene content. Since then, thousands of genomes from a wide array of strains from different sources have been sequenced. Comparison of these sequences has resulted in broad insights into population structure, bacterial evolution, clone emergence and expansion, and the molecular basis of niche adaptation. Furthermore, this information is now being applied clinically in outbreak investigations to inform infection control measures and to determine appropriate treatment regimens. In this review, we summarize some of the broad insights into S. aureus biology gained from the analysis of genomes and discuss future directions and opportunities in this dynamic field of research.

  15. Antimicrobial (Drug) Resistance: Methicillin-Resistant Staphylococcus aureus (MRSA)

    Science.gov (United States)

    ... Marketing Share this: Main Content Area Methicillin-Resistant Staphylococcus aureus (MRSA) During the past four decades, methicillin-resistant Staphylococcus aureus , or MRSA, has evolved from a controllable ...

  16. Evolution of methicillin-resistant Staphylococcus aureus towards increasing resistance

    DEFF Research Database (Denmark)

    Strommenger, Birgit; Bartels, Mette Damkjær; Kurt, Kevin;

    2014-01-01

    To elucidate the evolutionary history of Staphylococcus aureus clonal complex (CC) 8, which encompasses several globally distributed epidemic lineages, including hospital-associated methicillin-resistant S. aureus (MRSA) and the highly prevalent community-associated MRSA clone USA300....

  17. Propionibacterium acnes biofilm - A sanctuary for Staphylococcus aureus?

    Science.gov (United States)

    Tyner, Harmony; Patel, Robin

    2016-08-01

    The purpose of this study was to measure the effect of combined culture of Propionibacterium acnes and Staphylococcus aureus on biofilm formation under different oxygen concentrations. We measured planktonic growth and biofilm formation of P. acnes and S. aureus alone and together under aerobic and anaerobic conditions. Both P. acnes and S. aureus grew under anaerobic conditions. When grown under anaerobic conditions, P. acnes with or without S. aureus formed a denser biomass biofilm than did S. aureus alone. Viable S. aureus was recovered from a16-day old combined P. acnes and S. aureus biofilm, but not a monomicrobial S. aureus biofilm.

  18. Prevalence of infective endocarditis in patients with Staphylococcus aureus bacteraemia

    DEFF Research Database (Denmark)

    Rasmussen, Rasmus V; Høst, Ulla; Arpi, Magnus;

    2011-01-01

    Aims Staphylococcus aureus infective endocarditis (IE) is a critical medical condition associated with a high morbidity and mortality. In the present study, we prospectively evaluated the importance of screening with echocardiography in an unselected S. aureus bacteraemia (SAB) population. Methods...

  19. Comparative Efficacy of Ceftaroline with Linezolid against Staphylococcus Aureus and Methicillin Resistant Staphylococcus Aureus

    International Nuclear Information System (INIS)

    Objective:To compare the in vitro antimicrobial efficacy of ceftaroline with linezolid against Staphylococcus aureus and methicillin resistant Staphylococcus aureus. Study Design: Quasi-experimental study. Place and Duration of Study: Microbiology Department, Army Medical College, Rawalpindi, from January to December 2013. Methodology: Clinical samples from respiratory tract, blood, pus and various catheter tips routinely received in the Department of Microbiology, Army Medical College, Rawalpindi were innoculated on blood and MacConkey agar. Staphylococcus aureus was identified by colony morphology, Gram reaction, catalase test and coagulase test. Methicillin resistant Staphylococcus aureus detection was done by modified Kirby Bauer disc diffusion method using cefoxitin disc (30g) and the isolates were considered methicillin resistant if the zone of inhibition around cefoxitin disc was /sup 2/ 21 mm. Bacterial suspensions of 56 Staphylococcus aureus isolates and 50 MRSA isolates were prepared, which were standardized equal to 0.5 McFarland's turbidity standard and inoculated on Mueller-Hinton agar plates followed by application of ceftaroline and linezolid disc (Oxoid, UK), according to manufacturer's instructions. The plates were then incubated at 37 Degree C aerobically for 18 - 24 hours. Diameters of inhibition zone were measured and interpretated as per Clinical and Laboratory Standards Institute (CLSI) guidelines. Results: Out of 106 isolates all of the 56 Staphylococcus aureus (100%) were sensitive to ceftaroline and linezolid. However, out of 50 methicillin resistant Staphylococcus aureus, 48 (96%) were sensitive to ceftaroline whereas, 49 (98%) were sensitive to linezolid. Conclusion: Ceftaroline is equally effective as linezolid against Staphylococcus aureus and methicillin resistant Staphylococcus aureus. (author)

  20. Mastite com lesões sistêmicas por Staphylococus aureus subesp. aureus em coelhos Mastitis with systemic lesions due to Staphylococus aureus subesp. aureus in rabbits

    Directory of Open Access Journals (Sweden)

    Sandra Davi Traverso

    2003-04-01

    Full Text Available Em uma criação composta por 1800 coelhos, 33% das matrizes apresentaram mastite e lesões cutâneas crostosas e purulentas. Estes animais apresentavam-se entre 10 a- 12 meses de idade e em segunda parição. Quinze coelhos afetados foram sacrificados e necropsiados. Na necropsia, além das lesões cutâneas haviam microabscessos em diversos órgãos. Das amostras coletadas isolou-se Staphylococcus aureus subesp. aureus. S. aureus subesp. aureus também foi isolado de "swab" nasal coletado do tratador encarregado de fazer o diagnóstico de gestação nas coelhas. Histologicamente, havia formação de múltiplos abscessos, presença de bactérias gram positivas em vasos sangüíneos e linfáticos, além de êmbolos bacterianos nos tecidos. Nas mamas, observou-se tecido glandular normal associado a abscessos multifocais delimitados.At a commercial rabbitry which was composed of 1800 New Zealand White rabbits, 30% of the does had presented mastitis and purulent cutaneal lesions. The age of the animals ranged from 10 to 12 months and were at the second parturition. At necropsy, microabscesses were observed in several organs. Bacteriological samples collected from affected animals resulted Staphylococcus aureus subesp. aureus.. Additionally, the same agent has been isolated from a nasal swab collected from the person responsible for the pregnancy diagnosis. Histologically, there were multiple abscesses, gram positive bacteria within blood and lymphatic vessels, and bacterial emboli scattered in the tissues. In the mammas, normal glandular tissue associated with multifocal abscesses were observed.

  1. Staphylococcus aureus α-Toxin: Nearly a Century of Intrigue

    Directory of Open Access Journals (Sweden)

    Bryan J. Berube

    2013-06-01

    Full Text Available Staphylococcus aureus secretes a number of host-injurious toxins, among the most prominent of which is the small β-barrel pore-forming toxin α-hemolysin. Initially named based on its properties as a red blood cell lytic toxin, early studies suggested a far greater complexity of α-hemolysin action as nucleated cells also exhibited distinct responses to intoxication. The hemolysin, most aptly referred to as α-toxin based on its broad range of cellular specificity, has long been recognized as an important cause of injury in the context of both skin necrosis and lethal infection. The recent identification of ADAM10 as a cellular receptor for α-toxin has provided keen insight on the biology of toxin action during disease pathogenesis, demonstrating the molecular mechanisms by which the toxin causes tissue barrier disruption at host interfaces lined by epithelial or endothelial cells. This review highlights both the historical studies that laid the groundwork for nearly a century of research on α-toxin and key findings on the structural and functional biology of the toxin, in addition to discussing emerging observations that have significantly expanded our understanding of this toxin in S. aureus disease. The identification of ADAM10 as a proteinaceous receptor for the toxin not only provides a greater appreciation of truths uncovered by many historic studies, but now affords the opportunity to more extensively probe and understand the role of α-toxin in modulation of the complex interaction of S. aureus with its human host.

  2. Proteome changes of Caenorhabditis elegans upon a Staphylococcus aureus infection

    Directory of Open Access Journals (Sweden)

    Schoofs Liliane

    2010-02-01

    Full Text Available Abstract Background The success of invertebrates throughout evolution is an excellent illustration of the efficiency of their defence strategies. Caenorhabditis elegans has proven to be an appropriate model for transcriptome studies of host-pathogen interactions. The aim of this paper is to complement this knowledge by investigating the worm's response to a Staphylococcus aureus infection through a 2-dimensional differential proteomics approach. Results Different types of growth media in combination with either E. coli OP50 or Staphylococcus aureus were tested for an effect on the worm's lifespan. LB agar was chosen and C. elegans samples were collected 1 h, 4 h, 8 h and 24 h post S. aureus infection or E. coli incubation. Proteomics analyses resulted in the identification of 130 spots corresponding to a total of 108 differentially expressed proteins. Conclusions Exploring four time-points discloses a dynamic insight of the reaction against a gram-positive infection at the level of the whole organism. The remarkable upregulation after 8 h and 24 h of many enzymes involved in the citric acid cycle might illustrate the cost of fighting off an infection. Intriguing is the downregulation of chaperone molecules, which are presumed to serve a protective role. A comparison with a similar experiment in which C. elegans was infected with the gram-negative Aeromonas hydrophila reveals that merely 9% of the identified spots, some of which even exhibiting an opposite regulation, are present in both studies. Hence, our findings emphasise the complexity and pathogen-specificity of the worm's immune response and form a firm basis for future functional research. Reviewers This article was reviewed by Itai Yanai, Dieter Wolf and Torben Luebke (nominated by Walter Lutz.

  3. Meticillin-resistant Staphylococcus aureus (MRSA)

    DEFF Research Database (Denmark)

    Stefani, Stefania; Chung, Doo Ryeon; Lindsay, Jodi A;

    2012-01-01

    This article reviews recent findings on the global epidemiology of healthcare-acquired/associated (HA), community-acquired/associated (CA) and livestock-associated (LA) meticillin-resistant Staphylococcus aureus (MRSA) and aims to reach a consensus regarding the harmonisation of typing methods...... health. Continuous efforts to understand the changing epidemiology of S. aureus infection in humans and animals are therefore necessary, not only for appropriate antimicrobial treatment and effective infection control but also to monitor the evolution of the species. The group made several consensus...

  4. Biofilm-Forming Methicillin-Resistant Staphylococcus aureus Survive in Kupffer Cells and Exhibit High Virulence in Mice

    Directory of Open Access Journals (Sweden)

    Takuto Oyama

    2016-06-01

    Full Text Available Although Staphylococcus aureus is part of the normal body flora, heavy usage of antibiotics has resulted in the emergence of methicillin-resistant strains (MRSA. MRSA can form biofilms and cause indwelling foreign body infections, bacteremia, soft tissue infections, endocarditis, and osteomyelitis. Using an in vitro assay, we screened 173 clinical blood isolates of MRSA and selected 20 high-biofilm formers (H-BF and low-biofilm formers (L-BF. These were intravenously administered to mice and the general condition of mice, the distribution of bacteria, and biofilm in the liver, lung, spleen, and kidney were investigated. MRSA count was the highest in the liver, especially within Kupffer cells, which were positive for acid polysaccharides that are associated with intracellular biofilm. After 24 h, the general condition of the mice worsened significantly in the H-BF group. In the liver, bacterial deposition and aggregation and the biofilm-forming spot number were all significantly greater for H-BF group than for L-BF. CFU analysis revealed that bacteria in the H-BF group survived for long periods in the liver. These results indicate that the biofilm-forming ability of MRSA is a crucial factor for intracellular persistence, which could lead to chronic infections.

  5. 9 CFR 113.115 - Staphylococcus Aureus Bacterin-Toxoid.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Staphylococcus Aureus Bacterin-Toxoid... REQUIREMENTS Inactivated Bacterial Products § 113.115 Staphylococcus Aureus Bacterin-Toxoid. Staphylococcus Aureus Bacterin-Toxoid shall be prepared from toxoided broth cultures of selected toxogenic strains...

  6. A pig model of acute Staphylococcus aureus induced pyemia

    DEFF Research Database (Denmark)

    Nielsen, O. L.; Iburg, T.; Aalbæk, B.;

    2009-01-01

    Background: Sepsis caused by Staphylococcus aureus constitutes an important cause of morbidity and mortality in humans, and the incidence of this disease-entity is increasing. In this paper we describe the initial microbial dynamics and lesions in pigs experimentally infected with S. aureus....... aureus isolated from man and an extension of the timeframe aiming at inducing sepsis, severe sepsis and septic shock....

  7. Multidrug-Resistant Staphylococcus aureus in US Meat and Poultry

    OpenAIRE

    Waters, Andrew E.; Contente-Cuomo, Tania; Buchhagen, Jordan; Liu, Cindy M.; Watson, Lindsey; Pearce, Kimberly; Foster, Jeffrey T.; Bowers, Jolene; Driebe, Elizabeth M; Engelthaler, David M.; Keim, Paul S; Lance B Price

    2011-01-01

    We characterized the prevalence, antibiotic susceptibility profiles, and genotypes of Staphylococcus aureus among US meat and poultry samples (n = 136). S. aureus contaminated 47% of samples, and multidrug resistance was common among isolates (52%). S. aureus genotypes and resistance profiles differed significantly among sample types, suggesting food animal–specific contamination.

  8. Inhibitory Effect of Lactobacillus plantarum Extracts on HT-29 Colon Cancer Cell Apoptosis Induced by Staphylococcus aureus and Its Alpha-Toxin.

    Science.gov (United States)

    Kim, Hangeun; Kim, Hye Sun; Park, Woo Jung; Chung, Dae Kyun

    2015-11-01

    Staphylococcus aureus plays an important role in sepsis, septic shock, pneumonia, and wound infections. Here, we demonstrate that Lactobacillus plantarum extracts inhibited S. aureusinduced cell death of a human epithelial cell line, HT-29. In particular, we have shown that S. aureus-induced cell death was abolished by neutralization of α-toxin, indicating that α-toxin is the major mediator of S. aureus-induced cell death. DNA fragmentation experiment and caspase assay revealed that the S. aureus-induced cell death was apoptosis. L. plantarum extracts inhibited the generation of effector caspase-3 and the initiator caspase-9 in S. aureusor α-toxin-induced cell death. Moreover, expression of Bcl-2, an anti-apoptotic protein, was activated in L. plantarum extract-treated cells as compared with the S. aureus- or α-toxintreated only cells. Furthermore, S. aureus-induced apoptosis was efficiently inhibited by lipoteichoic acid and peptidoglycan of L. plantarum. Together, our results suggest that L. plantarum extracts can inhibit the S. aureus-mediated apoptosis, which is associated with S. aureus spreading, in intestinal epithelial cells, and may provide a new therapeutic reagent to treat bacterial infections.

  9. Emerging Community-Acquired Methicillin-Resistant Staphylococcus Aureus Pneumonia

    Directory of Open Access Journals (Sweden)

    Dragana Orlovic

    2009-04-01

    Full Text Available Background: Methicillin-resistant Staphylococcus aureus (MRSA has been an important nosocomial pathogen worldwide for more than four decades. Community-acquired MRSA infections, generally occurring in previously healthy persons without recognizable risk factors for health care setting-related MRSA, are emerging as serious clinical and public health concerns. The most frequent of these community-based infections include skin and soft tissue infections and necrotizing pneumonias. A majority of causative community-acquired MRSA (CA-MRSA isolates are associated with genes that encode the virulence factor, Panton-Valentine leukocidin (PVL toxin. Aims & Objectives: To describe six cases of CA-MRSA pneumonia recently admitted to our community hospital in Florida, and discuss the epidemiology, clinical features, and management of these expanding infections. Methods/Study Design: The medical records of six patients with radiographically-confirmed pneumonia and positive sputum cultures for MRSA at the time of hospitalization at the Lawnwood Regional Medical Center and Heart Institute, Fort Pierce, Florida, from December 2006 through January 2007, were retrospectively reviewed. All patients were seen by one of the authors (DO, an infectious diseases consultant. Lawnwood Regional Medical Center is a 341-bed, acute care institution and regional referral center for four counties of Treasure Coast, FL. The hospital institution review board gave permission for this study. Results/Findings: Six patients (5 men, 1 woman with CA-MRSA pneumonia were identified. The mean patient age was 57 years (range, 32-79 years. Three patients had no history of previous hospital admission, while two patients had been last hospitalized two years prior to the study admission. Three elderly patients had known co-morbidities predisposing to pneumonia including carcinoma of the lung (2 patients, and cirrhosis, diabetes mellitus, chronic renal failure, COPD, and cardiomyopathy (1

  10. Molecular typing and phenotype characterization of methicillin-resistant Staphylococcus aureus isolates from blood in Taiwan.

    Directory of Open Access Journals (Sweden)

    Wei-Yao Wang

    Full Text Available BACKGROUND: Staphylococcus aureus causes a variety of severe infections such as bacteremia and sepsis. At present, 60-80% of S. aureus isolates from Taiwan are methicillin resistant (MRSA. It has been shown that certain MRSA clones circulate worldwide. The goals of this study were to identify MRSA clones in Taiwan and to correlate the molecular types of isolates with their phenotypes. METHODS: A total of 157 MRSA isolates from bacteremic patients were collected from nine medical centers. They were typed based on polymorphisms in agr, SCCmec, MLST, spa, and dru. Phenotypes characterized included Panton-Valentine leucocidin (pvl, inducible macrolide-lincosamide-streptogramin B resistance (MLSBi, vancomycin (VA and daptomycin (DAP minimal inhibitory concentrations (MIC, and superantigenic toxin gene profiles. Difference between two consecutive samples was determined by Mann-Whitney-U test, and difference between two categorical variables was determined by Fisher's exact test. RESULTS: Four major MRSA clone complexes CC1, CC5, CC8, and CC59 were found, including 4 CC1, 9 CC5, 111 CC8, and 28 CC59 isolates. These clones had the following molecular types: CC1: SCCmecIV and ST573; CC5: SCCmecII and ST5; CC8: SCCmecIII, ST239, and ST241, and CC59: SCCmecIV, SCCmecV(T, ST59, and ST338. The toxin gene profiles of these clones were CC1: sec-seg-(sei-sell-selm-(seln-selo; CC5: sec-seg-sei-sell-selm-(seln-selp-tst1; CC8: sea-selk-selq, and CC59: seb-selk-selq. Most isolates with SCCmecV(T, ST59, spat437, and dru11 types were pvl(+ (13 isolates, while multidrug resistance (≥4 antimicrobials were associated with SCCmecIII, ST239, spa t037, agrI, and dru14 (119 isolates (p<0.001. One hundred and twenty four isolates with the following molecular types had higher VA MIC: SCCmecII and SCCmecIII; ST5, ST239, and ST241; spa t002, t037, and t421; dru4, dru10, dru12, dru13, and dru14 (p<0.05. No particular molecular types were found to be associated with MLSBi

  11. The psmα locus regulates production of Staphylococcus aureus alpha-toxin during infection.

    Science.gov (United States)

    Berube, Bryan J; Sampedro, Georgia R; Otto, Michael; Bubeck Wardenburg, Juliane

    2014-08-01

    Staphylococcus aureus is a leading cause of human bacterial infection, causing a wide spectrum of disease ranging from skin and soft tissue infections to life-threatening pneumonia and sepsis. S. aureus toxins play an essential role in disease pathogenesis, contributing to both immunomodulation and host tissue injury. Prominent among these toxins are the membrane-active pore-forming cytolysin alpha-toxin (Hla) and the amphipathic α-helical phenol-soluble modulin (PSM) peptides. As deletion of either the hla or psm locus leads to a phenotypically similar virulence defect in skin and soft tissue infection, we sought to determine the relative contribution of each locus to disease pathogenesis. Here we show that production of Hla can be modulated by PSM expression. An S. aureus mutant lacking PSM expression exhibits a transcriptional delay in hla mRNA production and therefore fails to secrete normal levels of Hla at early phases of growth. This leads to attenuation of virulence in vitro and in murine skin and lung models of infection, correlating with reduced recovery of Hla from host tissues. Production of Hla and restoration of staphylococcal virulence can be achieved in the psm mutant by plasmid-driven overexpression of hla. Our study suggests the coordinated action of Hla and PSMs in host tissue during early pathogenesis, confirming a major role for Hla in epithelial injury during S. aureus infection. These findings highlight the possibility that therapeutics targeting PSM production may simultaneously prevent Hla-mediated tissue injury.

  12. Oral antibiotics increase blood neutrophil maturation and reduce bacteremia and necrotizing enterocolitis in the immediate postnatal period of preterm pigs.

    Science.gov (United States)

    Nguyen, Duc Ninh; Fuglsang, Eva; Jiang, Pingping; Birck, Malene M; Pan, Xiaoyu; Kamal, Shamrulazhar B S; Pors, Susanne E; Gammelgaard, Pernille L; Nielsen, Dennis S; Thymann, Thomas; Levy, Ofer; Frøkiær, Hanne; Sangild, Per T

    2016-01-01

    Immature immunity may predispose preterm neonates to infections and necrotizing enterocolitis (NEC). Intravenous antibiotics are frequently given to prevent and treat sepsis, while oral antibiotics are seldom used. We hypothesized that oral antibiotics promote maturation of systemic immunity and delay gut bacterial colonization and thereby protect preterm neonates against both NEC and bacteremia in the immediate postnatal period. Preterm pigs were given formula and administered saline (CON) or broad-spectrum antibiotics orally (ORA) or systemically (SYS) for 5 d after birth. Temporal changes in blood parameters and bacterial composition in the intestine, blood and immune organs were analyzed. Newborn preterm pigs had few blood neutrophils and a high frequency of progenitor cells. Neutrophils gradually matured after preterm birth with increasing CD14 and decreasing CD172a expressions. Preterm neutrophil and monocyte TLR2 expression and TLR2-mediated blood cytokine responses were low relative to adults. ORA pigs showed enhanced blood neutrophil maturation with reduced cell size and CD172a expression. Only ORA pigs, but not SYS pigs, were protected from a high density of gut Gram-positive bacteria, high gut permeability, Gram-positive bacteremia and NEC. Neonatal oral antibiotics may benefit mucosal and systemic immunity via delayed gut colonization and enhanced blood neutrophil maturation just after preterm birth.

  13. Genetic Determination and Clonal Relationships of Staphylococcus aureus Isolated from Dairy Cows in Baturraden, Central Java, Indonesia

    Directory of Open Access Journals (Sweden)

    Fatkhanuddin Aziz

    2016-02-01

    Full Text Available Cases of mastitis in cows at Baturraden are leading to signifi cant and ongoing problems due to reducedproduction and lower milk quality. This study was designed to identify which of selected virulence determinantgenes of S. aureus are involved in the Baturraden infection, and to determine the clonal relationship amongthese isolates. Seventeen isolates were identifi ed as S. aureus based on their biochemical properties and speciesspecifi city for 23S rRNA and nuc genes. S. aureus isolates were genotypically characterized for the selectedvirulence determinants: coa, clfA, fnbA, fnbB, cap5, spa IgG and spa X- region genes. Clonal relationship analysisamong isolates was carried out using AFLP and results compared with previously confi rmed relationshipsbetween selected S. aureus isolated from other regions. The results show that eight isolates contain all thegenes, but six isolates lack fnbB and two isolates lack cap5 genes. AFLP analysis showed that all isolates of S.aureus originating from cows in Baturraden belong to one cluster. This study provides additional knowledgeabout S. aureus infection in Baturraden cows, including the number of virulence determinant genes that mayplay a role in pathogenicity.

  14. Staphylococcus aureus Entrance into the Dairy Chain: Tracking S. aureus from Dairy Cow to Cheese

    Science.gov (United States)

    Kümmel, Judith; Stessl, Beatrix; Gonano, Monika; Walcher, Georg; Bereuter, Othmar; Fricker, Martina; Grunert, Tom; Wagner, Martin; Ehling-Schulz, Monika

    2016-01-01

    Staphylococcus aureus is one of the most important contagious mastitis pathogens in dairy cattle. Due to its zoonotic potential, control of S. aureus is not only of great economic importance in the dairy industry but also a significant public health concern. The aim of this study was to decipher the potential of bovine udder associated S. aureus as reservoir for S. aureus contamination in dairy production and processing. From 18 farms, delivering their milk to an alpine dairy plant for the production of smeared semi-hard and hard cheese. one thousand hundred seventy six one thousand hundred seventy six quarter milk (QM) samples of all cows in lactation (n = 294) and representative samples form bulk tank milk (BTM) of all farms were surveyed for coagulase positive (CPS) and coagulase negative Staphylococci (CNS). Furthermore, samples from different steps of the cheese manufacturing process were tested for CPS and CNS. As revealed by chemometric-assisted FTIR spectroscopy and molecular subtyping (spa typing and multi locus sequence typing), dairy cattle represent indeed an important, yet underreported, entrance point of S. aureus into the dairy chain. Our data clearly show that certain S. aureus subtypes are present in primary production as well as in the cheese processing at the dairy plant. However, although a considerable diversity of S. aureus subtypes was observed in QM and BTM at the farms, only certain S. aureus subtypes were able to enter and persist in the cheese manufacturing at the dairy plant and could be isolated from cheese until day 14 of ripening. Farm strains belonging to the FTIR cluster B1 and B3, which show genetic characteristics (t2953, ST8, enterotoxin profile: sea/sed/sej) of the recently described S. aureus genotype B, most successfully contaminated the cheese production at the dairy plant. Thus, our study fosters the hypothesis that genotype B S. aureus represent a specific challenge in control of S. aureus in the dairy chain that requires

  15. Common R-plasmids in Staphylococcus aureus and Staphylococcus epidermidis during a nosocomial Staphylococcus aureus outbreak.

    OpenAIRE

    Cohen, M. L.; Wong, E. S.; Falkow, S

    1982-01-01

    During a 7-month period in 1978 to 1979, 31 patients and personnel at a Kentucky hospital were colonized or infected with a Staphylococcus aureus strain resistant to clindamycin, erythromycin, gentamicin, methicillin, penicillin, and tetracycline. S. epidermidis with similar antibiotic resistance patterns had been isolated in this hospital in the year before the S. aureus outbreak. A 32-megadalton R-plasmid, pUW3626, mediating resistance to penicillin and gentamicin, was present in these isol...

  16. Autophagy mediates tolerance to Staphylococcus aureus alpha-toxin.

    Science.gov (United States)

    Maurer, Katie; Reyes-Robles, Tamara; Alonzo, Francis; Durbin, Joan; Torres, Victor J; Cadwell, Ken

    2015-04-01

    Resistance and tolerance are two defense strategies employed by the host against microbial threats. Autophagy-mediated degradation of bacteria has been extensively described as a major resistance mechanism. Here we find that the dominant function of autophagy proteins during infections with the epidemic community-associated methicillin-resistant Staphylococcus aureus USA300 is to mediate tolerance rather than resistance. Atg16L1 hypomorphic mice (Atg16L1(HM)), which have reduced autophagy, were highly susceptible to lethality in both sepsis and pneumonia models of USA300 infection. Autophagy confers protection by limiting the damage caused by α-toxin, particularly to endothelial cells. Remarkably, Atg16L1(HM) mice display enhanced survival rather than susceptibility upon infection with α-toxin-deficient S. aureus. These results identify an essential role for autophagy in tolerance to Staphylococcal disease and highlight how a single virulence factor encoded by a pathogen can determine whether a given host factor promotes tolerance or resistance.

  17. Staphylococcus aureus resistente a la meticilina (SARM)

    Centers for Disease Control (CDC) Podcasts

    2007-10-22

    Datos importantes sobre las infecciones por SARM en Estados Unidos, en las escuelas y los entornos médicos. (Title: Methicillin-resistant Staphylococcus aureus (MRSA)Created: 10/2007).  Created: 10/22/2007 by National Center for Preparedness, Detection, and Control of Infectious Diseases.   Date Released: 11/9/2007.

  18. Methicillin-resistant Staphylococcus aureus transmission

    DEFF Research Database (Denmark)

    Andersen, Leif Percival; Nielsen, Xiaohui

    2015-01-01

    INTRODUCTION: Even though methicillin-resistant Staphylococcus aureus (MRSA) is a common cause of nosocomial infections, it may often be difficult to evaluate the exact route of transmission. METHODS: In this study, we describe four cases of nosocomial transmission of MRSA in a hospital with a low...

  19. Carriage of Staphylococcus aureus in the elderly

    NARCIS (Netherlands)

    R. M. Parnaby; G. O'Dwyer; H. A. Monsey; M. S. Shafi

    1996-01-01

    textabstractThe point prevalence and incidence of Staphylococcus aureus (methicillin-sensitive and -resistant) carriage by inpatients on acute elderly care wards was estimated. The relationship to body site and to previous admissions to hospital or other institutions was determined. Fifty-five patie

  20. Increasing resistance of Staphylococcus aureus to ciprofloxacin.

    OpenAIRE

    Daum, T E; Schaberg, D R; Terpenning, M S; Sottile, W S; Kauffman, C A

    1990-01-01

    We demonstrated the marked emergence of resistance to ciprofloxacin among Staphylococcus arueus strains isolated at the Ann Arbor Veterans Administration Medical Center. All S. aureus isolates tested from 1984 to 1985 were susceptible, whereas 55.1% of methicillin-resistant and 2.5% of methicillin-susceptible strains from 1989 had high-level resistance to ciprofloxacin.

  1. [Invasive pneumococcal disease in two non-vaccinated pediatric cases: pleural empyema and bacteremia].

    Science.gov (United States)

    Kanık Yüksek, Saliha; Gülhan, Belgin; Tezer, Hasan; Özkaya Parlakay, Aslınur; Uzun Kenan, Bahriye; Sayed Oskovi, Hülya; Nar Ötgün, Selin

    2015-07-01

    Streptococcus pneumoniae, a gram-positive diplococcus, is the causative agent of invasive pneumococcal diseases (IPDs) characterized by severe infections such as bacteraemia, sepsis and meningitis. S.pneumoniae and IPDs are situated in the focus of the vaccine studies because of being encompassed of a significant burden of disease in the world, severe mortality and morbidities, and location in vaccine-preventable diseases group. Although S.pneumoniae has more than 90 defined serotypes, certain serotypes are often identified as the cause of IPDs. Individuals with comorbid and chronic diseases, primary or secondary immune deficiencies, and 65 years of age are at increased risk for IPDs. Currently, a 23-valent polysaccharide vaccine and also 7, 10 and 13 valent pneumococcal conjugated vaccines (PCV) have been produced for pneumococci. Phase studies of protein based vaccines, which will provide protection independent of serotypes, and 15-valent pneumococcal conjugated vaccine are still ongoing. In Turkey, in November 2008 PCV7 and in April 2011 PCV13 have been implemented in the national immunization program. First case of the pneumococcal unvaccinated cases presented in this report was a 6-year-old girl patient with pneumonia and pleural empyema due to S.pneumoniae serotype 1, without any underlying risk factors. The other case is a 52-days-old male patient, who had a history of pneumococcal septicemia in the newborn period and was followed for bacteremia associated S.pneumoniae serotype 12B and diagnosed as complement deficiency on follow-up. S.pneumoniae serotype 1 is within serotypes covered by 10 and 13 valent pneumococcal conjugate vaccines and pneumococcal polysaccharide vaccine that are in use today, and is a highly invasive strain often isolated in pneumococcal lobar pneumonia and empyema. S.pneumoniae serotype 12B is a non-vaccine serotype not included in any of conjugate and polysaccharide vaccines, and usually obtained in respiratory infections and

  2. Periodontal status and bacteremia with oral viridans streptococci and coagulase negative staphylococci in allogeneic hematopoietic stem cell transplantation recipients: a prospective observational study

    NARCIS (Netherlands)

    J.E. Raber-Durlacher; A.M.G.A. Laheij; J.B. Epstein; M. Epstein; G.M. Geerligs; G.N. Wolffe; N.M.A. Blijlevens; J.P. Donnelly

    2013-01-01

    Aim This study was aimed to investigate whether any association could be found between the presence of an inflamed and infected periodontium (e.g., gingivitis and periodontitis) and the development of bacteremia during neutropenia following allogeneic hematopoietic stem cell transplantation (HSCT).

  3. Periodontal status and bacteremia with oral viridans streptococci and coagulase negative staphylococci in allogeneic hematopoietic stem cell transplantation recipients: a prospective observational study.

    NARCIS (Netherlands)

    Raber-Durlacher, J.E.; Laheij, A.M.; Epstein, J.B.; Epstein, M.; Geerligs, G.M.; Wolffe, G.N.; Blijlevens, N.M.A.; Donnelly, J.P.

    2013-01-01

    AIM: This study was aimed to investigate whether any association could be found between the presence of an inflamed and infected periodontium (e.g., gingivitis and periodontitis) and the development of bacteremia during neutropenia following allogeneic hematopoietic stem cell transplantation (HSCT).

  4. Impact of empirical treatment in extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella spp. bacteremia. A multicentric cohort study

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    Peralta Galo

    2012-10-01

    Full Text Available Abstract Background The objective of this study is to analyze the factors that are associated with the adequacy of empirical antibiotic therapy and its impact in mortality in a large cohort of patients with extended-spectrum β-lactamase (ESBL - producing Escherichia coli and Klebsiella spp. bacteremia. Methods Cases of ESBL producing Enterobacteriaceae (ESBL-E bacteremia collected from 2003 through 2008 in 19 hospitals in Spain. Statistical analysis was performed using multivariate logistic regression. Results We analyzed 387 cases ESBL-E bloodstream infections. The main sources of bacteremia were urinary tract (55.3%, biliary tract (12.7%, intra-abdominal (8.8% and unknown origin (9.6%. Among all the 387 episodes, E. coli was isolated from blood cultures in 343 and in 45.71% the ESBL-E was multidrug resistant. Empirical antibiotic treatment was adequate in 48.8% of the cases and the in hospital mortality was 20.9%. In a multivariate analysis adequacy was a risk factor for death [adjusted OR (95% CI: 0.39 (0.31-0.97; P = 0.04], but not in patients without severe sepsis or shock. The class of antibiotic used empirically was not associated with prognosis in adequately treated patients. Conclusion ESBL-E bacteremia has a relatively high mortality that is partly related with a low adequacy of empirical antibiotic treatment. In selected subgroups the relevance of the adequacy of empirical therapy is limited.

  5. Cost-Effectiveness of Routine 18F-FDG PET/CT in High-Risk Patients with Gram-Positive Bacteremia

    NARCIS (Netherlands)

    Vos, F.J.; Bleeker-Rovers, C.P.; Kullberg, B.J.; Adang, E.M.M.; Oyen, W.J.G.

    2011-01-01

    Gram-positive bacteremia has a high morbidity and mortality rate of approximately 30%. Delayed diagnosis of clinically silent metastatic infectious foci is an important indicator for a complicated outcome. (18)F-FDG PET/CT allows detection of focal infection, resulting in lower relapse rates and mor

  6. Central venous catheter-related bacteremia caused by Kocuria kristinae: Case report and review of the literature

    OpenAIRE

    David Michael Z; Bares Sara; Dunn Ryan

    2011-01-01

    Abstract Kocuria species are unusual human pathogens isolated most commonly from immunocompromised hosts, such as transplant recipients and cancer patients undergoing chemotherapy, or from patients with chronic medical conditions. A case of catheter-related bacteremia with pulmonary septic emboli in a pregnant adult female without chronic medical conditions is described. A review of other reported Kocuria infections is provided.

  7. Relationship between Vancomycin-Resistant Staphylococcus aureus, Vancomycin-Intermediate S. aureus, High Vancomycin MIC, and Outcome in Serious S. aureus Infections

    OpenAIRE

    Holmes, Natasha E.; Johnson, Paul D. R.; Howden, Benjamin P.

    2012-01-01

    Vancomycin has been used successfully for over 50 years for the treatment of Staphylococcus aureus infections, particularly those involving methicillin-resistant S. aureus. It has proven remarkably reliable, but its efficacy is now being questioned with the emergence of strains of S. aureus that display heteroresistance, intermediate resistance, and, occasionally, complete vancomycin resistance. More recently, an association has been established between poor outcome and infections with strain...

  8. Staphylococcus aureus Shifts toward Commensalism in Response to Corynebacterium Species.

    Science.gov (United States)

    Ramsey, Matthew M; Freire, Marcelo O; Gabrilska, Rebecca A; Rumbaugh, Kendra P; Lemon, Katherine P

    2016-01-01

    Staphylococcus aureus-human interactions result in a continuum of outcomes from commensalism to pathogenesis. S. aureus is a clinically important pathogen that asymptomatically colonizes ~25% of humans as a member of the nostril and skin microbiota, where it resides with other bacteria including commensal Corynebacterium species. Commensal Corynebacterium spp. are also positively correlated with S. aureus in chronic polymicrobial diabetic foot infections, distinct from acute monomicrobial S. aureus infections. Recent work by our lab and others indicates that microbe-microbe interactions between S. aureus and human skin/nasal commensals, including Corynebacterium species, affect S. aureus behavior and fitness. Thus, we hypothesized that S. aureus interactions with Corynebacterium spp. diminish S. aureus virulence. We tested this by assaying for changes in S. aureus gene expression during in vitro mono- versus coculture with Corynebacterium striatum, a common skin and nasal commensal. We observed a broad shift in S. aureus gene transcription during in vitro growth with C. striatum, including increased transcription of genes known to exhibit increased expression during human nasal colonization and decreased transcription of virulence genes. S. aureus uses several regulatory pathways to transition between commensal and pathogenic states. One of these, the quorum signal accessory gene regulator (agr) system, was strongly inhibited in response to Corynebacterium spp. Phenotypically, S. aureus exposed to C. striatum exhibited increased adhesion to epithelial cells, reflecting a commensal state, and decreased hemolysin activity, reflecting an attenuation of virulence. Consistent with this, S. aureus displayed diminished fitness in experimental in vivo coinfection with C. striatum when compared to monoinfection. These data support a model in which S. aureus shifts from virulence toward a commensal state when exposed to commensal Corynebacterium species.

  9. Staphylococcus aureus Shifts toward Commensalism in Response to Corynebacterium Species.

    Science.gov (United States)

    Ramsey, Matthew M; Freire, Marcelo O; Gabrilska, Rebecca A; Rumbaugh, Kendra P; Lemon, Katherine P

    2016-01-01

    Staphylococcus aureus-human interactions result in a continuum of outcomes from commensalism to pathogenesis. S. aureus is a clinically important pathogen that asymptomatically colonizes ~25% of humans as a member of the nostril and skin microbiota, where it resides with other bacteria including commensal Corynebacterium species. Commensal Corynebacterium spp. are also positively correlated with S. aureus in chronic polymicrobial diabetic foot infections, distinct from acute monomicrobial S. aureus infections. Recent work by our lab and others indicates that microbe-microbe interactions between S. aureus and human skin/nasal commensals, including Corynebacterium species, affect S. aureus behavior and fitness. Thus, we hypothesized that S. aureus interactions with Corynebacterium spp. diminish S. aureus virulence. We tested this by assaying for changes in S. aureus gene expression during in vitro mono- versus coculture with Corynebacterium striatum, a common skin and nasal commensal. We observed a broad shift in S. aureus gene transcription during in vitro growth with C. striatum, including increased transcription of genes known to exhibit increased expression during human nasal colonization and decreased transcription of virulence genes. S. aureus uses several regulatory pathways to transition between commensal and pathogenic states. One of these, the quorum signal accessory gene regulator (agr) system, was strongly inhibited in response to Corynebacterium spp. Phenotypically, S. aureus exposed to C. striatum exhibited increased adhesion to epithelial cells, reflecting a commensal state, and decreased hemolysin activity, reflecting an attenuation of virulence. Consistent with this, S. aureus displayed diminished fitness in experimental in vivo coinfection with C. striatum when compared to monoinfection. These data support a model in which S. aureus shifts from virulence toward a commensal state when exposed to commensal Corynebacterium species. PMID:27582729

  10. Cost Analysis of an Intervention to Prevent Methicillin-Resistant Staphylococcus Aureus (MRSA Transmission.

    Directory of Open Access Journals (Sweden)

    Michal Chowers

    Full Text Available Our objective was to assess the cost implications of a vertical MRSA prevention program that led to a reduction in MRSA bacteremia.We performed a matched historical cohort study and cost analysis in a single hospital in Israel for the years 2005-2011. The cost of MRSA bacteremia was calculated as total hospital cost for patients admitted with bacteremia and for patients with hospital-acquired bacteremia, the difference in cost compared to matched controls. The cost of prevention was calculated as the sum of the cost of microbiology tests, single-use equipment used for patients in isolation, and infection control personnel.An average of 20,000 patients were screened yearly. The cost of prevention was $208,100 per year, with the major contributor being laboratory cost. We calculated that our intervention averted 34 cases of bacteremia yearly: 17 presenting on admission and 17 acquired in the hospital. The average cost of a case admitted with bacteremia was $14,500, and the net cost attributable to nosocomial bacteremia was $9,400. Antibiotics contributed only 0.4% of the total disease management cost. When the annual cost of averted cases of bacteremia and that of prevention were compared, the intervention resulted in annual cost savings of $199,600.A vertical MRSA prevention program targeted at high-risk patients, which was highly effective in preventing bacteremia, is cost saving. These results suggest that allocating resources to targeted prevention efforts might be beneficial even in a single institution in a high incidence country.

  11. Cost Analysis of an Intervention to Prevent Methicillin-Resistant Staphylococcus Aureus (MRSA) Transmission

    Science.gov (United States)

    Chowers, Michal; Carmeli, Yehuda; Shitrit, Pnina; Elhayany, Asher; Geffen, Keren

    2015-01-01

    Introduction Our objective was to assess the cost implications of a vertical MRSA prevention program that led to a reduction in MRSA bacteremia. Methods We performed a matched historical cohort study and cost analysis in a single hospital in Israel for the years 2005-2011. The cost of MRSA bacteremia was calculated as total hospital cost for patients admitted with bacteremia and for patients with hospital-acquired bacteremia, the difference in cost compared to matched controls. The cost of prevention was calculated as the sum of the cost of microbiology tests, single-use equipment used for patients in isolation, and infection control personnel. Results An average of 20,000 patients were screened yearly. The cost of prevention was $208,100 per year, with the major contributor being laboratory cost. We calculated that our intervention averted 34 cases of bacteremia yearly: 17 presenting on admission and 17 acquired in the hospital. The average cost of a case admitted with bacteremia was $14,500, and the net cost attributable to nosocomial bacteremia was $9,400. Antibiotics contributed only 0.4% of the total disease management cost. When the annual cost of averted cases of bacteremia and that of prevention were compared, the intervention resulted in annual cost savings of $199,600. Conclusions A vertical MRSA prevention program targeted at high-risk patients, which was highly effective in preventing bacteremia, is cost saving. These results suggest that allocating resources to targeted prevention efforts might be beneficial even in a single institution in a high incidence country. PMID:26406889

  12. The nuclear factor kappa B (NF-κB) activation is required for phagocytosis of staphylococcus aureus by RAW 264.7 cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Fei, E-mail: zhufei@zju.edu.cn; Yue, Wanfu; Wang, Yongxia

    2014-10-01

    Nuclear factor kappa B (NF-κB) is a ubiquitous transcription factor which controls the expression of various genes involved in immune responses. However, it is not clear whether NF-κB activation is critical for phagocytosis when Staphylococcus aureus is the pathogen. Using oligonucleotide microarrays, we investigated whether NF-κB cascade genes are altered in a mouse leukemic monocyte macrophage cell line (RAW 264.7) when the cells were stimulated to activate a host innate immune response against live S. aureus or heat-inactivated S. aureus (HISA). NF-κB cascade genes such as Nfκb1, Nfκbiz, Nfκbie, Rel, Traf1 and Tnfaip3 were up-regulated by all treatments at one hour after incubation. NF-κB play an important role in activating phagocytosis in RAW 264.7 cells infected with S. aureus. Inhibition of NF-κB significantly blocked phagocytosis of fluorescently labeled S. aureus and decreased the expression of NFκB1, IL1α, IL1β and TLR2 in this cell line. Our results demonstrate that S. aureus may activate the NF-κB pathway and that NF-κB activation is required for phagocytosis of S. aureus by macrophages. - Highlights: • NF-κB cascade genes such as Nfκb1 and Traf1 were up-regulated by heat-inactivated S. aureus. • Inhibition of NF-κB significantly blocked phagocytosis of fluorescently labeled S. aureus. • NF-κB activation is required for phagocytosis of S. aureus by macrophages.

  13. Role of α-toxin-induced apoptosis of umbilical vein endothelial cells in vertical infection of Staphylococcus aureus L-form%α-毒素诱导的脐静脉内皮细胞凋亡在金葡菌L型垂直感染中的作用

    Institute of Scientific and Technical Information of China (English)

    管俊昌; 朱翔; 余峰玲; 杨文选; 刘婷婷; 张涛; 林娜; 刘勇; 刘从森

    2013-01-01

    目的 确定α-毒素诱导脐静脉内皮细胞(HUV-EC-C)的凋亡在金葡菌L型垂直感染中的作用.方法 在培养的HUV-EC-C细胞中加入不同浓度(0、10、30、90、270 ng/ml)的金葡菌α-毒素,处理不同时间(0、2、4、6、8h)后经Annexin V-PI染色,流式细胞仪检测HUV-EC-C细胞的凋亡率.通过ELISA检测α肿瘤坏死因子(TNF-α)、caspase-3与caspase-8的表达量,并观察加入TNF-α中口抗体、caspases-3抑制剂zDEVD-FMK、caspase-8抑制剂zIETD-fmk对α-毒素诱导HUV-EC-C细胞凋亡的影响.结果 α-毒素能够诱导HUV-EC-C细胞凋亡并表现为时间、剂量依赖性,明显增加HUV-EC-C细胞中TNF-α、caspase-3与caspase-8的表达;在加入TNF-α中和抗体、zDEVD-FMK、zIETD-fmk后可部分阻断α-毒素能够诱导的HUV-EC-C细胞凋亡.结论 α-毒素通过TNF-α及caspase-8介导的外源性死亡途径诱导HUV-EC-C细胞凋亡,表明α-毒素诱导内皮细胞凋亡是金葡菌L型垂直感染影响胎儿发育的主要机制之一.%Objective To investigate α-toxin-induced apoptosis of umbilical vein endothelial cells and explore its role in vertical infection of Staphylococcus aureus L-form.Methods HUV-EC-C cells exposed to different concentrations (0,10,30,90,and 270 ng/ml) of α-toxin for different time lengths (0,2,4,6,and 8 h) were examined for apoptosis using flow cytometry with Annexin V-PI staining.The levels of tumor necrosis factor-α (TNF-α) and the activities of,caspase-3 and caspase-8 in the cell culture were detected by ELISA and colorimetric method,respectively.α-Toxin-induced cell apoptosis was also analyzed in HUV-EC-C cells treated with a neutralizing antibody of TNF-α or with the inhibitory peptides of caspase-3 (zDEVD-FMK) and caspase-8 (zIETD-fmk).Results α-Toxin induced apoptosis of HUV-EC-C cells in a dose-and time-dependent manner and caused significantly enhanced expression of TNF-α and the activation of both caspase-3 and caspase-8.Inhibition of TNF-α with

  14. Correlation of American Burn Association sepsis criteria with the presence of bacteremia in burned patients admitted to the intensive care unit.

    Science.gov (United States)

    Hogan, Brian K; Wolf, Steven E; Hospenthal, Duane R; D'Avignon, Laurie C; Chung, Kevin K; Yun, Heather C; Mann, Elizabeth A; Murray, Clinton K

    2012-01-01

    Severe burn injury is accompanied by a systemic inflammatory response, making traditional indicators of sepsis both insensitive and nonspecific. To address this, the American Burn Association (ABA) published diagnostic criteria in 2007 to standardize the definition of sepsis in these patients. These criteria include temperature (>39°C or 110 beats per minute), progressive tachypnea (>25 breaths per minute not ventilated or minute ventilation >12 L/minute ventilated), thrombocytopenia (200 mg/dl, >7 units of insulin/hr intravenous drip, or >25% increase in insulin requirements over 24 hours), and feed intolerance >24 hours (abdominal distension, residuals two times the feeding rate, or diarrhea >2500 ml/day). Meeting >3 of these criteria should "trigger" concern for infection. In this initial assessment of the ABA sepsis criteria correlation with infection, the authors evaluated the ABA sepsis criteria's correlation with bacteremia because bacteremia is not associated with inherent issues of diagnosis as occurs with pneumonia or soft tissue infections, and blood cultures are typically obtained due to concern for ongoing infections falling within the definition of "septic." A retrospective electronic records review was performed to evaluate episodes of bacteremia in the United States Army Institute of Research from 2006 through 2007. A total of 196 patients were admitted during the study period who met inclusion criteria. The first positive and negative cultures, if present, from each patient were evaluated. This totaled 101 positive and 181 negative cultures. Temperature, heart rate, insulin resistance, and feed intolerance criteria were significant on univariate analysis. Only heart rate and temperature were found to significantly correlate with bacteremia on multivariate analysis. The receiver operating characteristic curve area for meeting >3 ABA sepsis criteria is 0.638 (95% confidence interval 0.573-0.704; P burn patients, the ABA trigger for sepsis did not

  15. Exploring the contribution of efflux on the resistance to fluoroquinolones in clinical isolates of Staphylococcus aureus

    LENUS (Irish Health Repository)

    Costa, Sofia SANTOS

    2011-10-27

    Abstract Background Antimicrobial resistance mediated by efflux systems is still poorly characterized in Staphylococcus aureus, despite the description of several efflux pumps (EPs) for this bacterium. In this work we used several methodologies to characterize the efflux activity of 52 S. aureus isolates resistant to ciprofloxacin collected in a hospital in Lisbon, Portugal, in order to understand the role played by these systems in the resistance to fluoroquinolones. Results Augmented efflux activity was detected in 12 out of 52 isolates and correlated with increased resistance to fluoroquinolones. Addition of efflux inhibitors did not result in the full reversion of the fluoroquinolone resistance phenotype, yet it implied a significant decrease in the resistance levels, regardless of the type(s) of mutation(s) found in the quinolone-resistance determining region of grlA and gyrA genes, which accounted for the remaining resistance that was not efflux-mediated. Expression analysis of the genes coding for the main efflux pumps revealed increased expression only in the presence of inducing agents. Moreover, it showed that not only different substrates can trigger expression of different EP genes, but also that the same substrate can promote a variable response, according to its concentration. We also found isolates belonging to the same clonal type that showed different responses towards drug exposure, thus evidencing that highly related clinical isolates may diverge in the efflux-mediated response to noxious agents. The data gathered by real-time fluorometric and RT-qPCR assays suggest that S. aureus clinical isolates may be primed to efflux antimicrobial compounds. Conclusions The results obtained in this work do not exclude the importance of mutations in resistance to fluoroquinolones in S. aureus, yet they underline the contribution of efflux systems for the emergence of high-level resistance. All together, the results presented in this study show the potential

  16. Nuclease modulates biofilm formation in community-associated methicillin-resistant Staphylococcus aureus.

    Directory of Open Access Journals (Sweden)

    Megan R Kiedrowski

    Full Text Available Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA is an emerging contributor to biofilm-related infections. We recently reported that strains lacking sigma factor B (sigB in the USA300 lineage of CA-MRSA are unable to develop a biofilm. Interestingly, when spent media from a USA300 sigB mutant was incubated with other S. aureus strains, biofilm formation was inhibited. Following fractionation and mass spectrometry analysis, the major anti-biofilm factor identified in the spent media was secreted thermonuclease (Nuc. Considering reports that extracellular DNA (eDNA is an important component of the biofilm matrix, we investigated the regulation and role of Nuc in USA300. The expression of the nuc gene was increased in a sigB mutant, repressed by glucose supplementation, and was unaffected by the agr quorum-sensing system. A FRET assay for Nuc activity was developed and confirmed the regulatory results. A USA300 nuc mutant was constructed and displayed an enhanced biofilm-forming capacity, and the nuc mutant also accumulated more high molecular weight eDNA than the WT and regulatory mutant strains. Inactivation of nuc in the USA300 sigB mutant background partially repaired the sigB biofilm-negative phenotype, suggesting that nuc expression contributes to the inability of the mutant to form biofilm. To test the generality of the nuc mutant biofilm phenotypes, the mutation was introduced into other S. aureus genetic backgrounds and similar increases in biofilm formation were observed. Finally, using multiple S. aureus strains and regulatory mutants, an inverse correlation between Nuc activity and biofilm formation was demonstrated. Altogether, our findings confirm the important role for eDNA in the S. aureus biofilm matrix and indicates Nuc is a regulator of biofilm formation.

  17. The prevalence of methicillin-resistant Staph. aureus strains producing enterotoxin A and B

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    Safiyeh Abbasi

    2016-02-01

    Full Text Available Background: Staphylococcus aureus is a gram positive coccus which is able to cause different kinds of infection in certain condition. The function of this bacteria is to provide the conditions for the invasion of it to the host with the secretion of different sorts of toxins such as Staphylococcus aureus enterotoxin, including important virulence factors that super antigens are all factors digestive inconvenience. Staphylococcus aureus enterotoxin-secreting toxins such conditions provides invasion of host genes. There are different types of SE, but type A enterotoxin (SEA and type B enterotoxin (SEB are the most important types. Therefore, in this study, the prevalence of Staphylococcus aureus toxin-producing enterotoxin genes (SEB, SEA in clinical strains isolated from patients in teaching hospitals of Shahrekord city, Iran, were studied. Methods: This cross-sectional and descriptive study, which was conducted from May 2014 to December 2014. A hundred and ten isolates of Staphylococcus aureus from patients collected over a period of 8 months and were first identified using standard biochemical methods and laboratory. Using standard methods and laboratory tests were identified and compared with the antibiotic oxacillin minimum inhibitory concentration were determined by broth micro dilution, and then they were assessed by polymerase chain reaction (PCR technique. Results: The results indicated that, 110 samples of dairy products infected by Staphylococcus aureus were detected. Two cases (1.8% of these infected samples were carrying both enterotoxin A and enterotoxin B genes. The frequencies of enterotoxin A genes were twenty-six cases (23/6% and The frequencies of enterotoxin B genes were two cases (1/8%, respectively. Conclusion: The detection of enterotoxin A and enterotoxin B genes, shows the most important role they have in bringing about superinfection. The detection of enterotoxin A and B genes, shows the most important role they have in

  18. YsxC, an essential protein in Staphylococcus aureus crucial for ribosome assembly/stability

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    García-Lara Jorge

    2009-12-01

    Full Text Available Abstract Background Bacterial growth and division requires a core set of essential proteins, several of which are still of unknown function. They are also attractive targets for the development of new antibiotics. YsxC is a member of a family of GTPases highly conserved across eubacteria with a possible ribosome associated function. Results Here, we demonstrate by the creation of a conditional lethal mutant that ysxC is apparently essential for growth in S. aureus. To begin to elucidate YsxC function, a translational fusion of YsxC to the CBP-ProteinA tag in the staphylococcal chromosome was made, enabling Tandem Affinity Purification (TAP of YsxC-interacting partners. These included the ribosomal proteins S2, S10 and L17, as well as the β' subunit of the RNA polymerase. YsxC was then shown to copurify with ribosomes as an accessory protein specifically localizing to the 50 S subunit. YsxC depletion led to a decrease in the presence of mature ribosomes, indicating a role in ribosome assembly and/or stability in S. aureus. Conclusions In this study we demonstrate that YsxC of S. aureus localizes to the ribosomes, is crucial for ribosomal stability and is apparently essential for the life of S. aureus.

  19. A systematic review and meta-analysis on Staphylococcus aureus carriage in psoriasis, acne and rosacea.

    Science.gov (United States)

    Totté, J E E; van der Feltz, W T; Bode, L G M; van Belkum, A; van Zuuren, E J; Pasmans, S G M A

    2016-07-01

    Staphylococcus aureus might amplify symptoms in chronic inflammatory skin diseases. This study evaluates skin and mucosal colonization with S. aureus in patients with psoriasis, acne and rosacea. A systematic literature search was conducted. Both odds ratios (OR) for colonization in patients versus controls and the prevalence of colonization in patients are reported. Fifteen articles about psoriasis and 13 about acne (12 having a control group) were included. No study in rosacea met our inclusion criteria. For psoriasis, one study out of three controlled studies showed increased skin colonization (OR 18.86; 95 % confidence interval [CI] 2.20-161.99). Three out of the five studies that reported on nasal colonization showed significant ORs varying from 1.73 (95 % CI 1.16-2.58) to 14.64 (95 % CI 2.82-75.95). For acne one of the three studies that evaluated skin colonization reported a significant OR of 4.16 (95 % CI 1.74-9.94). A relation between nasal colonization and acne was not found. Limitations in study design and low sample sizes should be taken into consideration when interpreting the results. Colonisation with S. aureus seems to be increased in patients with psoriasis. This bacterial species, known for its potential to induce long-lasting inflammation, might be involved in psoriasis pathogenesis. Information on acne is limited. Prospective controlled studies should further investigate the role of S. aureus in chronic inflammatory skin diseases. PMID:27151386

  20. Fosfomycin enhances phagocyte-mediated killing of Staphylococcus aureus by extracellular traps and reactive oxygen species.

    Science.gov (United States)

    Shen, Fengge; Tang, Xudong; Cheng, Wei; Wang, Yang; Wang, Chao; Shi, Xiaochen; An, Yanan; Zhang, Qiaoli; Liu, Mingyuan; Liu, Bo; Yu, Lu

    2016-01-01

    The successful treatment of bacterial infections is the achievement of a synergy between the host's immune defences and antibiotics. Here, we examined whether fosfomycin (FOM) could improve the bactericidal effect of phagocytes, and investigated the potential mechanisms. FOM enhanced the phagocytosis and extra- or intracellular killing of S. aureus by phagocytes. And FOM enhanced the extracellular killing of S. aureus in macrophage (MФ) and in neutrophils mediated by extracellular traps (ETs). ET production was related to NADPH oxidase-dependent reactive oxygen species (ROS). Additionally, FOM increased the intracellular killing of S. aureus in phagocytes, which was mediated by ROS through the oxidative burst process. Our results also showed that FOM alone induced S. aureus producing hydroxyl radicals in order to kill the bacterial cells in vitro. In a mouse peritonitis model, FOM treatment increased the bactericidal extra- and intracellular activity in vivo, and FOM strengthened ROS and ET production from peritoneal lavage fluid ex vivo. An IVIS imaging system assay further verified the observed in vivo bactericidal effect of the FOM treatment. This work may provide a deeper understanding of the role of the host's immune defences and antibiotic interactions in microbial infections. PMID:26778774