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  1. MRSA

    MedlinePlus

    Methicillin-resistant Staphylococcus aureus; Hospital-acquired MRSA (HA-MRSA); Staph - MRSA; Staphylococcal - MRSA ... Centers for Disease Control and Prevention. Methicillin-resistant Staphylococcus aureus (MRSA) infections. Updated March 1, 2016. www.cdc. ...

  2. MRSA

    MedlinePlus

    ... How Can I Help a Friend Who Cuts? MRSA KidsHealth > For Teens > MRSA Print A A A ... and how can you protect yourself? What Is MRSA? MRSA stands for methicillin-resistant Staphylococcus aureus . Staphylococcus_ ...

  3. Evolution of Staphylococcus aureus and MRSA during outbreaks.

    PubMed

    Lindsay, Jodi A

    2014-01-01

    Investigation of Staphylococcus aureus outbreaks, and particularly those due to methicillin-resistant S. aureus (MRSA) in hospitals, can identify infection reservoirs and prevent further colonization and infection. During outbreaks, S. aureus genomes develop single nucleotide polymorphisms (SNPs), small genetic rearrangements, and/or acquire and lose mobile genetic elements (MGE) encoding resistance and virulence genes. Whole genome sequencing (WGS) is the most powerful method for discriminating between related isolates and deciding which are involved in an outbreak. Isolates with only minor variations are detectable and can identify MRSA transmission routes and identify reservoirs. Some patients may carry 'clouds' of related isolates, and this has consequences for how we interpret the data from outbreak investigations. Different clones of MRSA are evolving at different rates, influencing their typability. S. aureus genome variation reveals the importance of antibiotic resistance in the long term evolution of successful hospital clones, contributing to strategies to prevent the spread of successful MRSA clones.

  4. Evolution of Staphylococcus aureus and MRSA during outbreaks.

    PubMed

    Lindsay, Jodi A

    2014-01-01

    Investigation of Staphylococcus aureus outbreaks, and particularly those due to methicillin-resistant S. aureus (MRSA) in hospitals, can identify infection reservoirs and prevent further colonization and infection. During outbreaks, S. aureus genomes develop single nucleotide polymorphisms (SNPs), small genetic rearrangements, and/or acquire and lose mobile genetic elements (MGE) encoding resistance and virulence genes. Whole genome sequencing (WGS) is the most powerful method for discriminating between related isolates and deciding which are involved in an outbreak. Isolates with only minor variations are detectable and can identify MRSA transmission routes and identify reservoirs. Some patients may carry 'clouds' of related isolates, and this has consequences for how we interpret the data from outbreak investigations. Different clones of MRSA are evolving at different rates, influencing their typability. S. aureus genome variation reveals the importance of antibiotic resistance in the long term evolution of successful hospital clones, contributing to strategies to prevent the spread of successful MRSA clones. PMID:23665384

  5. Evaluation of Two New Chromogenic Media, CHROMagar MRSA and S. aureus ID, for Identifying Staphylococcus aureus and Screening Methicillin-Resistant S. aureus

    PubMed Central

    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. PMID:16081989

  6. Predictive value of methicillin-resistant Staphylococcus aureus (MRSA) nasal swab PCR assay for MRSA pneumonia.

    PubMed

    Dangerfield, Benjamin; Chung, Andrew; Webb, Brandon; Seville, Maria Teresa

    2014-01-01

    Pneumonia due to methicillin-resistant Staphylococcus aureus (MRSA) is associated with poor outcomes and frequently merits empirical antibiotic consideration despite its relatively low incidence. Nasal colonization with MRSA is associated with clinical MRSA infection and can be reliably detected using the nasal swab PCR assay. In this study, we evaluated the performance of the nasal swab MRSA PCR in predicting MRSA pneumonia. A retrospective cohort study was performed in a tertiary care center from January 2009 to July 2011. All patients with confirmed pneumonia who had both a nasal swab MRSA PCR test and a bacterial culture within predefined time intervals were included in the study. These data were used to calculate sensitivity, specificity, positive predictive value, and negative predictive value for clinically confirmed MRSA pneumonia. Four hundred thirty-five patients met inclusion criteria. The majority of cases were classified as either health care-associated (HCAP) (54.7%) or community-acquired (CAP) (34%) pneumonia. MRSA nasal PCR was positive in 62 (14.3%) cases. MRSA pneumonia was confirmed by culture in 25 (5.7%) cases. The MRSA PCR assay demonstrated 88.0% sensitivity and 90.1% specificity, with a positive predictive value of 35.4% and a negative predictive value of 99.2%. In patients with pneumonia, the MRSA PCR nasal swab has a poor positive predictive value but an excellent negative predictive value for MRSA pneumonia in populations with low MRSA pneumonia incidence. In cases of culture-negative pneumonia where initial empirical antibiotics include an MRSA-active agent, a negative MRSA PCR swab can be reasonably used to guide antibiotic de-escalation.

  7. MRSA

    MedlinePlus

    MRSA stands for methicillin-resistant Staphylococcus aureus. It causes a staph infection (pronounced "staff infection") that is resistant to several common antibiotics. There are two types of infection. ...

  8. MRSA

    MedlinePlus

    ... that are no longer killed by penicillin-type antibiotics. Methicillin-resistant Staphylococcus aureus (MRSA) is a strain of staph bacteria that is resistant to penicillin and standard penicillin-related antibiotics. MRSA causes the same types of infections as ...

  9. Methicillin-Resistant Staphylococcus aureus (MRSA) Treatment

    MedlinePlus

    ... antibiotics, your provider will consider the potential for antibiotic resistance. Thus, if MRSA is suspected, your provider will avoid treating you with beta-lactam antibiotics, a class of antibiotic observed not to be ...

  10. Methicillin resistant Staphylococcus aureus (MRSA) infection in cystic fibrosis

    PubMed Central

    Miall, L; McGinley, N; Brownlee, K; Conway, S

    2001-01-01

    BACKGROUND—Methicillin resistant Staphylococcus aureus (MRSA) infection is increasingly found in patients with cystic fibrosis (CF).
AIMS—To determine whether MRSA infection has a deleterious effect on the clinical status of children with CF.
METHODS—Children with MRSA in respiratory cultures during a seven year period were identified and compared with controls matched for age, sex, and respiratory function. Respiratory function tests, anthropometric data, Shwachman-Kulczycki score, Northern chest x ray score, intravenous and nebulised antibiotic therapy, and steroid therapy were compared one year before and one year after MRSA infection.
RESULTS—From a clinic population of 300, 10 children had positive sputum or cough swab cultures for MRSA. Prevalence rose from 0 in 1992-1994 to 7 in 1998. Eighteen controls were identified. Children with MRSA showed significant worsening of height standard deviation scores and required twice as many courses of intravenous antibiotics as controls after one year. They had significantly worse chest x ray scores at the time of the first MRSA isolate and one year later, but showed no increase in the rate of decline in chest x ray appearance. There was a trend towards lower FEV1 and FEF25-75 in children with MRSA. There were no significant differences between the two groups with respect to change in weight, body mass index, or Shwachman score. There was no significant difference in prior use of steroids or nebulised antibiotics.
CONCLUSION—MRSA infection in children with CF does not significantly affect respiratory function, but may have an adverse effect on growth. Children with MRSA require significantly more courses of intravenous antibiotics and have a worse chest x ray appearance than controls.

 PMID:11159295

  11. Comparison of BD GeneOhm Methicillin-Resistant Staphylococcus aureus (MRSA) PCR versus the CHROMagar MRSA Assay for Screening Patients for the Presence of MRSA Strains▿

    PubMed Central

    Boyce, John M.; Havill, Nancy L.

    2008-01-01

    We compared the BD GeneOhm methicillin-resistant Staphylococcus aureus (MRSA) real-time PCR assay with the CHROMagar MRSA assay for the detection of MRSA in 286 nasal surveillance specimens. Compared with the CHROMagar MRSA assay, PCR had sensitivity, specificity, positive predictive value, and negative predictive values of 100%, 98.6%, 95.8%, and 100%, respectively. The mean PCR turnaround time was 14.5 h. PMID:18032616

  12. Performance of CHROMagar MRSA Medium for Detection of Methicillin-Resistant Staphylococcus aureus

    PubMed Central

    Diederen, Bram; van Duijn, Inge; van Belkum, Alex; Willemse, Piet; van Keulen, Peter; Kluytmans, Jan

    2005-01-01

    CHROMagar MRSA was evaluated for its ability to identify methicillin-resistant Staphylococcus aureus (MRSA). A well-defined collection consisting of 216 MRSA strains and 241 methicillin-susceptible Staphylococcus aureus isolates was used. The sensitivity of CHROMagar MRSA after 24 h of incubation was 95.4%, increasing to 100% after 48 h. The specificity was already 100% after 24 h. PMID:15815020

  13. Blue Light Phototherapy Kills Methycillin Resistant Staphylococcus Aureus (MRSA)

    NASA Astrophysics Data System (ADS)

    Enwemeka, Chukuka S.; Williams, Debora; Enwemeka, Sombiri K.; Hollosi, Steve; Yens, David

    2010-05-01

    Background: Methycillin resistant staphylococcus aureus (MRSA) bacteria continue to defy most available antibiotics. As a result infections with MRSA remain a growing public health concern. As a paradigm shift and a significant departure from the on-going trend to develop stronger drug-based therapies, we studied the effect of 405 nm and 470 nm wavelengths of blue light on two strains of MRSA—US-300 strain of CA-MRSA and the IS853 strain of HA-MRSA—in vitro. Methods: We cultured and plated each strain, following which bacteria colonies were irradiated with 0, 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 25, 30, 35, 40, 45, 50, 55, or 60 Jcm-2 energy densities—just once. Specimens were incubated at 35° C for 24 h. Then, digital images obtained were quantified to obtain colony counts and the aggregate area occupied by bacteria colonies. Results: Each wavelength produced a statistically significant dose-dependent reduction in both the number and the aggregate area of colonies formed by each bacteria strain (P<0.001). Maximum eradication of the US-300 (92.1%) and the IS-853 colonies (93.5%) was achieved within 10 minutes of irradiation with each wavelength. The longer the irradiation the more bacteria were eradicated. However, the effect was non-linear as increases of energy densities between 1.0 and 15 J cm-2 resulted in more bacteria death than similar increases between 15 J cm-2 and 60 J cm-2. Conclusion: At low doses, blue light photo-destroys HA-MRSA and CA-MRSA in vitro; raising the prospect that phototherapy may be an effective clinical tool in the on-going effort to stem MRSA infections.

  14. Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) at ambient freshwater beaches.

    PubMed

    Fogarty, Lisa R; Haack, Sheridan K; Johnson, Heather E; Brennan, Angela K; Isaacs, Natasha M; Spencer, Chelsea

    2015-09-01

    Methicillin-resistant Staphylococcus aureus (MRSA) are a threat to human health worldwide, and although detected at marine beaches, they have been largely unstudied at freshwater beaches. Genes indicating S. aureus (SA; femA) and methicillin resistance (mecA) were detected at 11 and 12 of 13 US Great Lakes beaches and in 18% or 27% of 287 recreational water samples, respectively. Eight beaches had mecA+femA (potential MRSA) detections. During an intensive study, higher bather numbers, staphylococci concentrations, and femA detections were found in samples collected after noon than before noon. Local population density, beach cloud cover, and beach wave height were significantly correlated with SA or MRSA detection frequency. The Panton-Valentine leukocidin gene, associated with community-acquired MRSA, was detected in 12 out of 27 potential MRSA samples. The femA gene was detected less frequently at beaches that met US enterococci criteria or EU enterococci 'excellent' recreational water quality, but was not related to Escherichia coli-defined criteria. Escherichia coli is often the only indicator used to determine water quality at US beaches, given the economic and healthcare burden that can be associated with infections caused by SA and MRSA, monitoring of recreational waters for non-fecal bacteria such as staphylococci and/or SA may be warranted.

  15. Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) at ambient freshwater beaches

    USGS Publications Warehouse

    Fogarty, Lisa R.; Haack, Sheridan K.; Johnson, Heather E.; Brennan, Angela K.; Isaacs, Natasha M.; Spencer, Chelsea

    2015-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) are a threat to human health worldwide, and although detected at marine beaches, they have been largely unstudied at freshwater beaches. Genes indicating S. aureus (SA; femA) and methicillin resistance (mecA) were detected at 11 and 12 of 13 US Great Lakes beaches and in 18% or 27% of 287 recreational water samples, respectively. Eight beaches had mecA + femA (potential MRSA) detections. During an intensive study, higher bather numbers, staphylococci concentrations, and femA detections were found in samples collected after noon than before noon. Local population density, beach cloud cover, and beach wave height were significantly correlated with SA or MRSA detection frequency. The Panton-Valentine leukocidin gene, associated with community-acquired MRSA, was detected in 12 out of 27 potential MRSA samples. The femA gene was detected less frequently at beaches that met US enterococci criteria or EU enterococci ‘excellent’ recreational water quality, but was not related to Escherichia coli-defined criteria. Escherichia coli is often the only indicator used to determine water quality at US beaches, given the economic and healthcare burden that can be associated with infections caused by SA and MRSA, monitoring of recreational waters for non-fecal bacteria such as staphylococci and/or SA may be warranted.

  16. Long-Term Risk for Readmission, Methicillin-Resistant Staphylococcus aureus (MRSA) Infection, and Death among MRSA-Colonized Veterans

    PubMed Central

    Quezada Joaquin, Nestor M.; Diekema, Daniel J.; Perencevich, Eli N.; Bailey, George; Winokur, Patricia L.

    2013-01-01

    While numerous studies have assessed the outcomes of methicillin-resistant S. aureus (MRSA) colonization over the short term, little is known about longer-term outcomes after discharge. An assessment of long-term outcomes could provide information about the utility of various MRSA prevention approaches. A matched-cohort study was performed among Veterans Affairs (VA) patients screened for MRSA colonization between the years 2007 and 2009 and followed to evaluate outcomes until 2010. Cox proportional-hazard models were used to evaluate the association between MRSA colonization and long-term outcomes, such as infection-related readmission and crude mortality. A total of 404 veterans were included, 206 of whom were MRSA carriers and 198 of whom were noncarriers. There were no culture-proven MRSA infections on readmission among the noncarriers, but 13% of MRSA carriers were readmitted with culture-proven MRSA infections on readmission (P < 0.01). MRSA carriers were significantly more likely to be readmitted, to be readmitted more than once due to proven or probable MRSA infections, and to be readmitted within 90 days of discharge than noncarriers (P < 0.05). Infection-related readmission (adjusted hazard ratio [HR] = 4.07; 95% confidence interval [CI], 2.16 to 7.67) and mortality (adjusted HR = 2.71; 95% CI, 1.87 to 3.91) were significantly higher among MRSA carriers than among noncarriers after statistically adjusting for potential confounders. Among a cohort of VA patients, MRSA carriers are at high risk of infection-related readmission, MRSA infection, and mortality compared to noncarriers. Noncarriers are at very low risk of subsequent MRSA infection. Future studies should address whether interventions such as nasal or skin decolonization could result in improved outcomes for MRSA carriers. PMID:23254427

  17. Long-term risk for readmission, methicillin-resistant Staphylococcus aureus (MRSA) infection, and death among MRSA-colonized veterans.

    PubMed

    Quezada Joaquin, Nestor M; Diekema, Daniel J; Perencevich, Eli N; Bailey, George; Winokur, Patricia L; Schweizer, Marin L

    2013-03-01

    While numerous studies have assessed the outcomes of methicillin-resistant S. aureus (MRSA) colonization over the short term, little is known about longer-term outcomes after discharge. An assessment of long-term outcomes could provide information about the utility of various MRSA prevention approaches. A matched-cohort study was performed among Veterans Affairs (VA) patients screened for MRSA colonization between the years 2007 and 2009 and followed to evaluate outcomes until 2010. Cox proportional-hazard models were used to evaluate the association between MRSA colonization and long-term outcomes, such as infection-related readmission and crude mortality. A total of 404 veterans were included, 206 of whom were MRSA carriers and 198 of whom were noncarriers. There were no culture-proven MRSA infections on readmission among the noncarriers, but 13% of MRSA carriers were readmitted with culture-proven MRSA infections on readmission (P < 0.01). MRSA carriers were significantly more likely to be readmitted, to be readmitted more than once due to proven or probable MRSA infections, and to be readmitted within 90 days of discharge than noncarriers (P < 0.05). Infection-related readmission (adjusted hazard ratio [HR] = 4.07; 95% confidence interval [CI], 2.16 to 7.67) and mortality (adjusted HR = 2.71; 95% CI, 1.87 to 3.91) were significantly higher among MRSA carriers than among noncarriers after statistically adjusting for potential confounders. Among a cohort of VA patients, MRSA carriers are at high risk of infection-related readmission, MRSA infection, and mortality compared to noncarriers. Noncarriers are at very low risk of subsequent MRSA infection. Future studies should address whether interventions such as nasal or skin decolonization could result in improved outcomes for MRSA carriers.

  18. Prevalence of MRSA strains among Staphylococcus aureus isolated from outpatients, 2006.

    PubMed

    Coombs, Geoffrey W; Nimmo, Graeme R; Pearson, Julie C; Christiansen, Keryn J; Bell, Jan M; Collignon, Peter J; McLaws, Mary-Louise

    2009-03-01

    Biennial community-based Staphylococcus aureus antimicrobial surveillance programs have been performed by the Australian Group for Antimicrobial Resistance (AGAR) since 2000. Over this time the percentage of S. aureus identified as methicillin resistant has increased significantly from 10.3% in 2000 to 16% in 2006. This increase has occurred throughout Australia and has been due to the emergence of community-associated MRSA (CA-MRSA) clones. However, healthcare associated MRSA were still predominant in New South Wales/Australian Capital Territory and Victoria/Tasmania. In the 2006 survey CA-MRSA accounted for 8.8% of community-onset S. aureus infections. Although multiple CA-MRSA clones were characterised, the predominate clone identified was Queensland (Qld) MRSA (ST93-MRSA-IV) a Panton-Valentine leukocidin (PVL) positive MRSA that was first reported in Queensland and northern New South Wales in 2003 but has now spread throughout Australia. Several international PVL-positive CA-MRSA clones were also identified including USA300 MRSA (ST8-MRSA-IV). In addition, PVL was detected in an EMRSA-15 (ST22-MRSA-IV) isolate; a hospital associated MRSA clone that is known to be highly transmissible in the healthcare setting. With the introduction of the international clones and the transmission of Qld MRSA throughout the country, over 50% of CA-MRSA in Australia are now PVL positive. This change in the epidemiology of CA-MRSA in the Australian community will potentially result in an increase in skin and soft tissue infections in young Australians. As infections caused by these strains frequently results in hospitalisation their emergence is a major health concern.

  19. Rapid Identification of Methicillin-Resistant Staphylococcus aureus (MRSA) by the Vitek MS Saramis system.

    PubMed

    Shan, Weiguang; Li, Jiaping; Fang, Ying; Wang, Xuan; Gu, Danxia; Zhang, Rong

    2016-01-01

    A rapid, sensitive, and accurate Vitek MS assay was developed to distinguish clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) from clinical isolates of methicillin-sensitive Staphylococcus aureus (MSSA) by developing an in-house knowledgebase of SuperSpectra. Three unique peaks, including peaks at 2305.6 and 3007.3 Da specific to MRSA, and 6816.7 Da specific to MSSA, were selected for differentiating MRSA and MSSA. This assay accurately identified 84 and 91% of clinical MRSA and MSSA strains out of the total 142 clinically acquired S. aureus strains that were tested. This method will greatly improve the efficiency of single clinical sample identification of MRSA, thereby facilitating a reduction in the transmission of MRSA in clinical settings.

  20. Methicillin-resistant Staphylococcus aureus (MRSA): a community-based prevalence survey.

    PubMed Central

    Abudu, L.; Blair, I.; Fraise, A.; Cheng, K. K.

    2001-01-01

    A prevalence survey of nasal methicillin-resistant Staphylococcus aureus (MRSA) carriage was undertaken on a random sample of adults (aged over 16) resident in the community in Birmingham, UK during 1998. Microbiological samples were taken from the anterior nares at the subjects' general practice or in their home. Information about risk factors for the acquisition of MRSA was obtained via a self-completed questionnaire. A 58% response rate (280/483) was achieved. The prevalence of nasal MRSA colonization was 1.5% [4/274, 95% confidence interval (CI) 0.03-2.9%]. Twenty-three per cent (63/274) of subjects were nasal carriers of S. aureus. Six per cent (4/63) of S. aureus isolates were MRSA and 2 of the 4 MRSA carriers reported previous contact with health facilities. The prevalence of MRSA colonization in the general adult population in Birmingham appears to be low. PMID:11467791

  1. Molecular Typing of MRSA and of Clinical Staphylococcus aureus Isolates from Iaşi, Romania

    PubMed Central

    Monecke, Stefan; Müller, Elke; Dorneanu, Olivia Simona; Vremeră, Teodora; Ehricht, Ralf

    2014-01-01

    Romania is one of the countries with the highest prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in the world. To obtain data on affiliation of MRSA to strains and clonal complexes and on the population of methicillin susceptible S. aureus (MSSA), clinical isolates from bloodstream infections, skin and soft tissue infections as well as from screening swabs were collected at hospitals in Ia?i, a city in the North-Eastern part of Romania. Isolates were characterised by microarray hybridisation. Nearly half of all isolates (47%), and about one third (34%) of bloodstream isolates were MRSA. The prevalence of the Panton-Valentine leukocidin (PVL) was also high (31% among MRSA, 14% among MSSA). The most common MRSA strain was a PVL-negative CC1-MRSA-IV that might have emerged locally, as a related MSSA was also common. PVL-positive CC8-MRSA-IV (“USA300”) and PVL-negative ST239-like MRSA-III were also frequently found while other MRSA strains were only sporadically detected. Among MSSA, PVL-positive CC121 as well as PVL-negative CC1, CC22 and CC45 predominated. Although this study provides only a snapshot of S. aureus/MRSA epidemiology in Romania, it confirms the high burden of MRSA and PVL on Romanian healthcare settings. PMID:24846009

  2. Molecular typing of MRSA and of clinical Staphylococcus aureus isolates from Iaşi, Romania.

    PubMed

    Monecke, Stefan; Müller, Elke; Dorneanu, Olivia Simona; Vremeră, Teodora; Ehricht, Ralf

    2014-01-01

    Romania is one of the countries with the highest prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in the world. To obtain data on affiliation of MRSA to strains and clonal complexes and on the population of methicillin susceptible S. aureus (MSSA), clinical isolates from bloodstream infections, skin and soft tissue infections as well as from screening swabs were collected at hospitals in Ia?i, a city in the North-Eastern part of Romania. Isolates were characterised by microarray hybridisation. Nearly half of all isolates (47%), and about one third (34%) of bloodstream isolates were MRSA. The prevalence of the Panton-Valentine leukocidin (PVL) was also high (31% among MRSA, 14% among MSSA). The most common MRSA strain was a PVL-negative CC1-MRSA-IV that might have emerged locally, as a related MSSA was also common. PVL-positive CC8-MRSA-IV ("USA300") and PVL-negative ST239-like MRSA-III were also frequently found while other MRSA strains were only sporadically detected. Among MSSA, PVL-positive CC121 as well as PVL-negative CC1, CC22 and CC45 predominated. Although this study provides only a snapshot of S. aureus/MRSA epidemiology in Romania, it confirms the high burden of MRSA and PVL on Romanian healthcare settings.

  3. Methicillin-Resistant Staphylococcus aureus (MRSA) Detection: Comparison of Two Molecular Methods (IDI-MRSA PCR Assay and GenoType MRSA Direct PCR Assay) with Three Selective MRSA Agars (MRSA ID, MRSASelect, and CHROMagar MRSA) for Use with Infection-Control Swabs▿

    PubMed Central

    van Hal, S. J.; Stark, D.; Lockwood, B.; Marriott, D.; Harkness, J.

    2007-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is an increasing problem. Rapid detection of MRSA-colonized patients has the potential to limit spread of the organism. We evaluated the sensitivities and specificities of MRSA detection by two molecular methods (IDI-MRSA PCR assay and GenoType MRSA Direct PCR assay) and three selective MRSA agars (MRSA ID, MRSASelect, and CHROMagar MRSA), using 205 (101 nasal, 52 groin, and 52 axillary samples) samples from consecutive known MRSA-infected and/or -colonized patients. All detection methods had higher MRSA detection rates for nasal swabs than for axillary and groin swabs. Detection of MRSA by IDI-MRSA was the most sensitive method, independent of the site (94% for nasal samples, 80% for nonnasal samples, and 90% overall). The sensitivities of the GenoType MRSA Direct assay and the MRSA ID, MRSASelect, and CHROMagar MRSA agars with nasal swabs were 70%, 72%, 68%, and 75%, respectively. All detection methods had high specificities (95 to 99%), independent of the swab site. Extended incubation for a further 24 h with selective MRSA agars increased the detection of MRSA, with a corresponding decline in specificity secondary to a significant increase in false-positive results. There was a noticeable difference in test performance of the GenoType MRSA Direct assay in detection of MRSA (28/38 samples [74%]) compared with detection of nonmultiresistant MRSA (17/31 samples [55%]) (susceptible to two or more non-β-lactam antibiotics). This was not observed with selective MRSA agar plates or IDI-MRSA. Although it is more expensive, in addition to rapid turnaround times of 2 to 4 h, IDI-MRSA offers greater detection of MRSA colonization, independent of the swab site, than do conventional selective agars and GenoType MRSA Direct. PMID:17537949

  4. Patients with Methicillin-Resistant Staphylococcus aureus (MRSA) Infection – 21st Century Lepers

    PubMed Central

    Mozzillo, Kristin L.; Ortiz, Nancy; Miller, Loren G.

    2009-01-01

    In the recent past, there has been a dramatic increase in the incidence of methicillin-resistant Staphylococcus aureus (MRSA) infections, especially community-associated methicillin-resistant S. aureus (CA-MRSA) infections. Many media descriptions of MRSA are sensational and focus on its potential for severe disease and contagiousness. Our objective is to describe psychological and social morbidity associated with MRSA infection via a case series of five patients with CA-MRSA infection. We also analyze the resulting stigmatization associated with being diagnosed with MRSA infection. We learned that patients describe a variety of stigmatization related to their diagnosis of MRSA, including being shunned at home and in the workplace. Patients describe being asked by family, colleagues, and clients to take extraordinary measures to prevent MRSA transmission. Consequences of MRSA diagnoses have included erosion or termination of key personal and business relationships. In conclusion, stigmatization resulting from the diagnosis of MRSA can have profound personal and social morbidity. Media and public health awareness of MRSA infection needs to be balanced with information about how MRSA transmission is usually preventable with simple hygienic measures. PMID:20236730

  5. Comparison of Methicillin Resistant Staphylococcus Aureus in Healthy Community Hospital Visitors [CA-MRSA] and Hospital Staff [HA-MRSA

    PubMed Central

    Pathare, Nirmal A; Tejani, Sara; Asogan, Harshini; Al Mahruqi, Gaitha; Al Fakhri, Salma; Zafarulla, Roshna; Pathare, Anil V.

    2015-01-01

    Background The prevalence of community-associated methicillin-resistant Staphylococcus aureus [CA-MRSA] is unknown in Oman. Methods Nasal and cell phones swabs were collected from hospital visitors and health-care workers on sterile polyester swabs and directly inoculated onto a mannitol salt agar containing oxacillin, allowing growth of methicillin-resistant microorganisms. Antibiotic susceptibility tests were performed using Kirby Bauer’s disc diffusion method on the isolates. Minimum inhibitory concentration (MIC) was determined for vancomycin and teicoplanin against the resistant isolates of MRSA by the Epsilometer [E] test. A brief survey questionnaire was requested be filled to ascertain the exposure to known risk factors for CA-MRSA carriage. Results Overall, nasal colonization with CA-MRSA was seen in 34 individuals (18%, 95% confidence interval [CI] =12.5%–23.5%), whereas, CA-MRSA was additionally isolated from the cell phone surface in 12 participants (6.3%, 95% CI =5.6%–6.98%). Nasal colonization prevalence with hospital-acquired [HA] MRSA was seen in 16 individuals (13.8%, 95% confidence interval [CI] =7.5%–20.06%), whereas, HA-MRSA was additionally isolated from the cell phone surface in 3 participants (2.6%, 95% CI =1.7–4.54). Antibiotic sensitivity was 100% to linezolid and rifampicin in the CA-MRSA isolates. Antibiotic resistance to vancomycin and clindamycin varied between 9–11 % in the CA-MRSA isolates. Mean MIC for vancomycin amongst CA- and HA-MRSA were 6.3 and 9.3 μg/ml, whereas for teicoplanin they were 13 and 14 μg/ml respectively by the E-test. There was no statistically significant correlation between CA-MRSA nasal carriage and the risk factors (P>0.05, Chi-square test). Conclusions The prevalence of CA-MRSA in the healthy community hospital visitors was 18 % (95% CI, 12.5% to 23.5%) as compared to 13.8% HA-MRSA in the hospital health-care staff. Despite a significant prevalence of CA-MRSA, these strains were mostly sensitive

  6. Global epidemiology of community-associated methicillin resistant Staphylococcus aureus (CA-MRSA).

    PubMed

    Mediavilla, José R; Chen, Liang; Mathema, Barun; Kreiswirth, Barry N

    2012-10-01

    During the 1990s, various reports of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infections appeared in the literature, caused by novel strains genetically distinct from traditional healthcare-associated MRSA (HA-MRSA). Numerous lineages of CA-MRSA have since emerged on every continent, several of which have spread internationally, most notably USA300. CA-MRSA strains are increasingly implicated in nosocomial infections, and may eventually displace HA-MRSA strains in hospitals. Consequently, distinctions based on clinical epidemiology and susceptibility are becoming less relevant, arguing in favor of genotypic definitions. We review the current molecular epidemiology of CA-MRSA with respect to genetic diversity, global distribution, and factors related to its emergence and spread.

  7. Use of BBL CHROMagar MRSA Medium for Identification of Methicillin-Resistant Staphylococcus aureus Directly from Blood Cultures

    PubMed Central

    Pape, John; Wadlin, Jill; Nachamkin, Irving

    2006-01-01

    We evaluated the ability of BBL CHROMagar MRSA medium (Becton Dickinson, Sparks, MD) to identify methicillin-resistant Staphylococcus aureus (MRSA) directly upon subculture from positive blood culture bottles. There were 124 MRSA isolates recovered from blood cultures in the study. BBL CHROMagar MRSA medium was highly sensitive (97.6% [121/124] at 18 to 24 h of incubation and 100% [124/124] at 48 h) and 99.9% specific for identifying MRSA from positive blood cultures. PMID:16825383

  8. New patterns of methicillin-resistant Staphylococcus aureus (MRSA) clones, community-associated MRSA genotypes behave like healthcare-associated MRSA genotypes within hospitals, Argentina.

    PubMed

    Egea, Ana L; Gagetti, Paula; Lamberghini, Ricardo; Faccone, Diego; Lucero, Celeste; Vindel, Ana; Tosoroni, Dario; Garnero, Analía; Saka, Hector A; Galas, Marcelo; Bocco, José L; Corso, Alejandra; Sola, Claudia

    2014-11-01

    Methicillin-resistant Staphylococcus aureus (MRSA) burden is increasing worldwide in hospitals [healthcare-associated (HA)-MRSA] and in communities [community-associated (CA)-MRSA]. However, the impact of CA-MRSA within hospitals remains limited, particularly in Latin America. A countrywide representative survey of S. aureus infections was performed in Argentina by analyzing 591 clinical isolates from 66 hospitals in a prospective cross-sectional, multicenter study (Nov-2009). This work involved healthcare-onset infections-(HAHO, >48 hospitalization hours) and community-onset (CO) infections [including both, infections (HACO) in patients with healthcare-associated risk-factors (HRFs) and infections (CACO) in those without HRFs]. MRSA strains were genetically typed as CA-MRSA and HA-MRSA genotypes (CA-MRSAG and HA-MRSAG) by SCCmec- and spa-typing, PFGE, MLST and virulence genes profile by PCR. Considering all isolates, 63% were from CO-infections and 55% were MRSA [39% CA-MRSAG and 16% HA-MRSAG]. A significantly higher MRSA proportion among CO- than HAHO-S. aureus infections was detected (58% vs 49%); mainly in children (62% vs 43%). The CA-MRSAG/HA-MRSAG have accounted for 16%/33% of HAHO-, 39%/13% of HACO- and 60.5%/0% of CACO-infections. Regarding the epidemiological associations identified in multivariate models for patients with healthcare-onset CA-MRSAG infections, CA-MRSAG behave like HA-MRSAG within hospitals but children were the highest risk group for healthcare-onset CA-MRSAG infections. Most CA-MRSAG belonged to two major clones: PFGE-type N-ST30-SCCmecIVc-t019-PVL(+) and PFGE-type I-ST5-IV-SCCmecIVa-t311-PVL(+) (45% each). The ST5-IV-PVL(+)/ST30-IV-PVL(+) clones have caused 31%/33% of all infections, 20%/4% of HAHO-, 43%/23% of HACO- and 35%/60% of CACO- infections, with significant differences by age groups (children/adults) and geographical regions. Importantly, an isolate belonging to USA300-0114-(ST8-SCCmecIVa-spat008-PVL(+)-ACME(+)) was detected

  9. Methicillin-resistant Staphylococcus aureus (MRSA) as a cause of nosocomial wound infections.

    PubMed

    Sisirak, Maida; Zvizdic, Amra; Hukic, Mirsada

    2010-02-01

    Postoperative wound infections represent about 16% of hospital-acquired infections. Staphylococcus aureus is the most common cause of nosocomial wound infections. Increased frequency of Methicillin-resistant Staphylococcus aureus (MRSA) in hospitalized patients and possibility of vancomycin resistance requires permanent control of MRSA spread in the hospital.The purpose of this study was to analyse the frequency of Methicillin-resistant Staphylococcus aureus (MRSA) in the swabs taken from the surgical wounds, the presence of MRSA infection in surgical departments and to examine antimicrobial susceptibility of MRSA isolates. Wound swabs were examined from January 2006 to December 2008. The isolates were identified by conventional methods. Antimicrobial susceptibility testing was performed by Kirby-Bauer disc-diffusion method as per NCCLS guidelines.A total of 5755 wound swabs were examined: 938 (16,3%) swabs were sterile and 4817 (83,7%) were positive. Staphylococcus aureus was isolated in 1050 (22,0%) swabs and it was the most common cause of wound infections. MRSA was isolated from 12,4% samples in 2006, from 6,7% samples in 2007 and from 3,7% samples during 2008. Wound infections caused by MRSA dominated in the department of plastic surgery (24,4%) and in the department of orthopaedic surgery (24,1%). Antimicrobial susceptibility testing showed that 73% of MRSA isolates were with the same antibiotic sensitivity pattern (antibiotyp)-sensitive only to vancomycin, tetracycline, fucid acid and trimethoprim/sulfamethoxasole. Our results show decreasing of MRSA infection in the surgical wards. These results appear to be maintained with strategies for preventing nosocomial infection: permanent education, strong application of protocols and urging the implementation of strict infection control policy.

  10. Chloride anion transporters inhibit growth of methicillin-resistant Staphylococcus aureus (MRSA) in vitro.

    PubMed

    Share, Andrew I; Patel, Khushali; Nativi, Cristina; Cho, Eun J; Francesconi, Oscar; Busschaert, Nathalie; Gale, Philip A; Roelens, Stefano; Sessler, Jonathan L

    2016-06-18

    A series of aminopyrrolic receptors were tested as anion transporters using POPC liposome model membranes. Many were found to be effective Cl(-) transporters and to inhibit clinical strains of Staphylococcus aureus growth in vitro. The best transporters proved effective against the methicillin-resistant Staphylococcus aureus (MRSA) strains, Mu50 and HP1173. Tris-thiourea tren-based chloride transporters were also shown to inhibit the growth of S. aureus in vitro.

  11. Detection of mecA- and mecC-Positive Methicillin-Resistant Staphylococcus aureus (MRSA) Isolates by the New Xpert MRSA Gen 3 PCR Assay.

    PubMed

    Becker, Karsten; Denis, Olivier; Roisin, Sandrine; Mellmann, Alexander; Idelevich, Evgeny A; Knaack, Dennis; van Alen, Sarah; Kriegeskorte, André; Köck, Robin; Schaumburg, Frieder; Peters, Georg; Ballhausen, Britta

    2016-01-01

    An advanced methicillin-resistant Staphylococcus aureus (MRSA) detection PCR approach targeting SCCmec-orfX along with mecA and mecC was evaluated for S. aureus and coagulase-negative staphylococci. The possession of mecA and/or mecC was correctly confirmed in all cases. All methicillin-susceptible S. aureus strains (n = 98; including staphylococcal cassette chromosome mec element [SCCmec] remnants) and 98.1% of the MRSA strains (n = 160, including 10 mecC-positive MRSA) were accurately categorized.

  12. Detection of mecA- and mecC-Positive Methicillin-Resistant Staphylococcus aureus (MRSA) Isolates by the New Xpert MRSA Gen 3 PCR Assay.

    PubMed

    Becker, Karsten; Denis, Olivier; Roisin, Sandrine; Mellmann, Alexander; Idelevich, Evgeny A; Knaack, Dennis; van Alen, Sarah; Kriegeskorte, André; Köck, Robin; Schaumburg, Frieder; Peters, Georg; Ballhausen, Britta

    2016-01-01

    An advanced methicillin-resistant Staphylococcus aureus (MRSA) detection PCR approach targeting SCCmec-orfX along with mecA and mecC was evaluated for S. aureus and coagulase-negative staphylococci. The possession of mecA and/or mecC was correctly confirmed in all cases. All methicillin-susceptible S. aureus strains (n = 98; including staphylococcal cassette chromosome mec element [SCCmec] remnants) and 98.1% of the MRSA strains (n = 160, including 10 mecC-positive MRSA) were accurately categorized. PMID:26491186

  13. Detection of mecA- and mecC-Positive Methicillin-Resistant Staphylococcus aureus (MRSA) Isolates by the New Xpert MRSA Gen 3 PCR Assay

    PubMed Central

    Denis, Olivier; Roisin, Sandrine; Idelevich, Evgeny A.; Knaack, Dennis; van Alen, Sarah; Kriegeskorte, André; Köck, Robin; Schaumburg, Frieder; Peters, Georg; Ballhausen, Britta

    2015-01-01

    An advanced methicillin-resistant Staphylococcus aureus (MRSA) detection PCR approach targeting SCCmec-orfX along with mecA and mecC was evaluated for S. aureus and coagulase-negative staphylococci. The possession of mecA and/or mecC was correctly confirmed in all cases. All methicillin-susceptible S. aureus strains (n = 98; including staphylococcal cassette chromosome mec element [SCCmec] remnants) and 98.1% of the MRSA strains (n = 160, including 10 mecC-positive MRSA) were accurately categorized. PMID:26491186

  14. Meticillin-resistant Staphylococcus aureus (MRSA): global epidemiology and harmonisation of typing methods.

    PubMed

    Stefani, Stefania; Chung, Doo Ryeon; Lindsay, Jodi A; Friedrich, Alex W; Kearns, Angela M; Westh, Henrik; Mackenzie, Fiona M

    2012-04-01

    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 for MRSA. MRSA rates continue to increase rapidly in many regions and there is a dynamic spread of strains across the globe. HA-MRSA is currently endemic in hospitals in most regions. CA-MRSA clones have been spreading rapidly in the community and also infiltrating healthcare in many regions worldwide. To date, LA-MRSA is only prevalent in certain high-risk groups of workers in direct contact with live animals. CA-MRSA and LA-MRSA have become a challenge for countries that have so far maintained low rates of MRSA. These evolutionary changes have resulted in MRSA continuing to be a major threat to public 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 decisions with regard to harmonisation of typing methods. A stratified, three-level organisation of testing laboratories was proposed: local; regional; and national. The functions of, and testing methodology used by, each laboratory were defined. The group consensus was to recommend spa and staphylococcal cassette chromosome mec (SCCmec) typing as the preferred methods. Both are informative in defining particular strain characteristics and utilise standardised nomenclatures, making them applicable globally. Effective communication between each of the different levels and between national centres was viewed as being crucial to inform and monitor the molecular epidemiology of MRSA at national and international levels.

  15. Alternative use for spectra MRSA chromogenic agar in detection of methicillin-resistant Staphylococcus aureus from positive blood cultures.

    PubMed

    Peterson, Jess F; Dionisio, Alexander A; Riebe, Katherine M; Hall, Gerri S; Wilson, Deborah A; Whittier, Susan; Dipersio, Joseph R; Ledeboer, Nathan A

    2010-06-01

    Spectra MRSA agar (Remel, Lenexa, KS), a novel chromogenic medium originally developed to detect methicillin-resistant Staphylococcus aureus (MRSA) from nasal swabs, was evaluated in this multicenter study for the detection of MRSA from positive blood cultures exhibiting Gram-positive cocci upon initial Gram staining.

  16. [Treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections in Latin America].

    PubMed

    Luna, Carlos M; Rodríguez-Noriega, Eduardo; Bavestrello, Luis; Gotuzzo, Eduardo

    2010-08-01

    The global spread of MRSA means it is now a pathogen of worldwide public health concern. Within Latin America, MRSA is highly prevalent, with the proportion of S. aureus isolates that are methicillin-resistant on the rise, yet resources for managing the infection are limited. While several guidelines exist for the treatment of MRSA infections, many are written for the North American or European setting and need adaptation for use in Latin America. In this article, we aim to emphasize the importance of appropriate treatment of MRSA in the healthcare and community settings of Latin America. We present a summary of the available guidelines and antibiotics, and discuss particular considerations for clinicians treating MRSA in Latin America. PMID:21137164

  17. [Treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections in Latin America].

    PubMed

    Luna, Carlos M; Rodríguez-Noriega, Eduardo; Bavestrello, Luis; Gotuzzo, Eduardo

    2010-08-01

    The global spread of MRSA means it is now a pathogen of worldwide public health concern. Within Latin America, MRSA is highly prevalent, with the proportion of S. aureus isolates that are methicillin-resistant on the rise, yet resources for managing the infection are limited. While several guidelines exist for the treatment of MRSA infections, many are written for the North American or European setting and need adaptation for use in Latin America. In this article, we aim to emphasize the importance of appropriate treatment of MRSA in the healthcare and community settings of Latin America. We present a summary of the available guidelines and antibiotics, and discuss particular considerations for clinicians treating MRSA in Latin America.

  18. Methicillin-Resistant Staphylococcus aureus (MRSA) Detected at Four U.S. Wastewater Treatment Plants

    PubMed Central

    Goldstein, Rachel E. Rosenberg; Micallef, Shirley A.; Gibbs, Shawn G.; Davis, Johnnie A.; He, Xin; George, Ashish; Kleinfelter, Lara M.; Schreiber, Nicole A.; Mukherjee, Sampa; Joseph, Sam W.

    2012-01-01

    Background: The incidence of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infections is increasing in the United States, and it is possible that municipal wastewater could be a reservoir of this microorganism. To date, no U.S. studies have evaluated the occurrence of MRSA in wastewater. Objective: We examined the occurrence of MRSA and methicillin-susceptible S. aureus (MSSA) at U.S. wastewater treatment plants. Methods: We collected wastewater samples from two Mid-Atlantic and two Midwest wastewater treatment plants between October 2009 and October 2010. Samples were analyzed for MRSA and MSSA using membrane filtration. Isolates were confirmed using biochemical tests and PCR (polymerase chain reaction). Antimicrobial susceptibility testing was performed by Sensititre® microbroth dilution. Staphylococcal cassette chromosome mec (SCCmec) typing, Panton-Valentine leucocidin (PVL) screening, and pulsed field gel electrophoresis (PFGE) were performed to further characterize the strains. Data were analyzed by two-sample proportion tests and analysis of variance. Results: We detected MRSA (n = 240) and MSSA (n = 119) in 22 of 44 (50%) and 24 of 44 (55%) wastewater samples, respectively. The odds of samples being MRSA-positive decreased as treatment progressed: 10 of 12 (83%) influent samples were MRSA-positive, while only one of 12 (8%) effluent samples was MRSA-positive. Ninety-three percent and 29% of unique MRSA and MSSA isolates, respectively, were multidrug resistant. SCCmec types II and IV, the pvl gene, and USA types 100, 300, and 700 (PFGE strain types commonly found in the United States) were identified among the MRSA isolates. Conclusions: Our findings raise potential public health concerns for wastewater treatment plant workers and individuals exposed to reclaimed wastewater. Because of increasing use of reclaimed wastewater, further study is needed to evaluate the risk of exposure to antibiotic-resistant bacteria in treated

  19. Is methicillin-resistant Staphylococcus aureus (MRSA) contamination of ward-based computer terminals a surrogate marker for nosocomial MRSA transmission and handwashing compliance?

    PubMed

    Devine, J; Cooke, R P; Wright, E P

    2001-05-01

    A survey of two acute district general hospitals (A and B) was undertaken to investigate the extent of methicillin-resistant Staphylococcus aureus (MRSA) contamination of ward-based computer terminals. Of 25 terminals examined, MRSA was identified in six (24%). Environmental contamination was of a low level. Five of the MRSA positive terminals were from hospital A which had a significantly higher rate of MRSA transmission compared to hospital B (1.02 vs. 0.49 new inpatient MRSA cases per 100 hospital admissions for 1999). MRSA containment and handwashing policies were similar at both hospitals, though only hospital B actively audited handwashing compliance and had a 44% higher rate of paper towel usage per hospital bed. Ward-based computer terminals pose a low risk of MRSA cross-infection. This risk can be further reduced if all staff wash their hands before and after patient contact.

  20. Is methicillin-resistant Staphylococcus aureus (MRSA) contamination of ward-based computer terminals a surrogate marker for nosocomial MRSA transmission and handwashing compliance?

    PubMed

    Devine, J; Cooke, R P; Wright, E P

    2001-05-01

    A survey of two acute district general hospitals (A and B) was undertaken to investigate the extent of methicillin-resistant Staphylococcus aureus (MRSA) contamination of ward-based computer terminals. Of 25 terminals examined, MRSA was identified in six (24%). Environmental contamination was of a low level. Five of the MRSA positive terminals were from hospital A which had a significantly higher rate of MRSA transmission compared to hospital B (1.02 vs. 0.49 new inpatient MRSA cases per 100 hospital admissions for 1999). MRSA containment and handwashing policies were similar at both hospitals, though only hospital B actively audited handwashing compliance and had a 44% higher rate of paper towel usage per hospital bed. Ward-based computer terminals pose a low risk of MRSA cross-infection. This risk can be further reduced if all staff wash their hands before and after patient contact. PMID:11358473

  1. Evaluation of the LightCycler methicillin-resistant Staphylococcus aureus (MRSA) advanced test for detection of MRSA nasal colonization.

    PubMed

    Yam, W C; Siu, Gilman K H; Ho, P L; Ng, T K; Que, T L; Yip, K T; Fok, Cathie P K; Chen, Jonathan H K; Cheng, Vincent C C; Yuen, K Y

    2013-09-01

    Rapid detection of methicillin-resistant Staphylococcus aureus (MRSA) nasal colonization is crucial for the prevention and control of MRSA infections in health care settings. The LightCycler MRSA Advanced Test (Roche Diagnostics) is a commercially available real-time PCR assay for direct detection of MRSA nasal colonization by targeting of the staphylococcal cassette chromosome mec (SCCmec)-orfX junction. The diagnostic performance of the assay was compared with that of ChromID MRSA agar (bioMérieux) culture and an in-house duplex real-time PCR assay. Among 1,246 nasal swab specimens collected from 2 general hospitals in Hong Kong, 174 (14%) were considered true positive for MRSA. Chromogenic culture and the in-house real-time PCR assay identified 147 (84.5%) and 133 (76.4%) true-positive cases with specificities of 100% and 98.6%, respectively. Based on the target melting temperature (Tm) values (57.0 to 62.0 °C) defined by the manufacturer, the LightCycler MRSA Advanced Test identified only 85 (48.9%) true-positive specimens. Interestingly, an additional 60 (34.5%) true-positive specimens were detected despite atypical Tm values of 55 °C, providing overall sensitivity and specificity values of 83.3% and 99%, respectively. Among isolates with Tm values of 55 °C, most were typed as clonal complex 45 (CC45). By sequence analysis of the SCCmec-orfX junction, characteristic single-nucleotide polymorphisms (SNPs) were identified only in isolates with Tm values of 55°C and not in those with typical Tm values. It is conceivable that those SNPs were located inside the target region of the proprietary hybridization probes, which resulted in a Tm shift in the melting curve analysis. Our study highlights the importance of a global evaluation of commercial kits so that the interpretation algorithm covers different lineages of MRSA clones prevalent in various geographical regions.

  2. Methicillin-resistant Staphylococcus aureus (MRSA): is there a need to change clinical practice?

    PubMed

    Baird, V L; Hawley, R

    2000-12-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a virulent organism that causes significant mortality and morbidity especially to patients in critical care areas (CCAs). MRSA can (and does in some cases) also contribute to an increased length of hospital stay and higher health care costs. The literature proposes that routine screening of patients in CCAs is an effective strategy to control MRSA. Furthermore, placing patients in contact isolation until screening results are confirmed can prevent the spread of MRSA. The policies for management of MRSA patients and the incidence of MRSA infection vary widely. The preliminary findings from this review suggest that a uniform policy regarding routine screening and infection control management for all CCA patients should be recommended. A uniform policy has the potential to reduce rates of infection, cross-contamination and associated health costs attributed to MRSA management. However, further research is required before changes to infection control policy can be recommended. The outcomes from this review will be used to increase staff awareness of current infection control practices for MRSA patients in critical care areas and encourage further research.

  3. The economic burden of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA).

    PubMed

    Lee, B Y; Singh, A; David, M Z; Bartsch, S M; Slayton, R B; Huang, S S; Zimmer, S M; Potter, M A; Macal, C M; Lauderdale, D S; Miller, L G; Daum, R S

    2013-06-01

    The economic impact of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) remains unclear. We developed an economic simulation model to quantify the costs associated with CA-MRSA infection from the societal and third-party payer perspectives. A single CA-MRSA case costs third-party payers $2277-$3200 and society $7070-$20 489, depending on patient age. In the United States (US), CA-MRSA imposes an annual burden of $478 million to 2.2 billion on third-party payers and $1.4-13.8 billion on society, depending on the CA-MRSA definitions and incidences. The US jail system and Army may be experiencing annual total costs of $7-11 million ($6-10 million direct medical costs) and $15-36 million ($14-32 million direct costs), respectively. Hospitalization rates and mortality are important cost drivers. CA-MRSA confers a substantial economic burden on third-party payers and society, with CA-MRSA-attributable productivity losses being major contributors to the total societal economic burden. Although decreasing transmission and infection incidence would decrease costs, even if transmission were to continue at present levels, early identification and appropriate treatment of CA-MRSA infections before they progress could save considerable costs.

  4. Evaluation of six agglutination tests for Staphylococcus aureus identification depending upon local prevalence of meticillin-resistant S. aureus (MRSA).

    PubMed

    Weist, Klaus; Cimbal, Ann-Katrin; Lecke, Christoph; Kampf, Günter; Rüden, Henning; Vonberg, Ralf-Peter

    2006-03-01

    Most routine laboratory detection of Staphylococcus aureus isolates is based on rapid agglutination test systems. Failure of agglutination assays to identify meticillin-resistant S. aureus strains (MRSA) has been demonstrated. The aim of this study was to evaluate six commercially available agglutination tests for the detection of meticillin-sensitive S. aureus (MSSA) and mecA-positive MRSA strains. The Dry Spot Staphytect Plus test (Oxoid), the Pastorex Staph Plus test (Bio-Rad), the Slidex Staph-Kit and Slidex Staph Plus test (bioMérieux), the Staphaurex Plus test (Remel) and the Staphylase Test (Oxoid) were used. As determined by pulsed field gel electrophoresis, 52 distinct MRSA strains from five countries, 83 MSSA strains and 150 coagulase-negative staphylococci were included. Species identification and determination of susceptibility patterns were performed using colony morphology, Gram stain, catalase testing, tube coagulase testing, DNase testing, mannitol fermentation, susceptibility testing towards oxacillin by Etest, coagulase gene PCR, fibrinogen receptor gene PCR and PCR of the mecA gene. Sensitivity of the agglutination tests ranged from 82.7 to 100.0 % for MRSA strains and 92.8 to 100.0 % for MSSA strains, respectively. Specificity of the test systems ranged from 91.3 to 99.1 %. None of the six agglutination assays produced correct reactions for all staphylococci tested. Only the Dry Spot Staphytect Plus test correctly identified all 52 MRSA strains. For the other tests kits, sensitivity of MRSA detection was lower than for MSSA isolates. Depending upon the local MRSA prevalence and the parameter of interest (sensitivity or specificity), these test systems may be useful for routine diagnostic purposes.

  5. Epidemiology of emerging methicillin-resistant Staphylococcus aureus (MRSA) in Denmark: a nationwide study in a country with low prevalence of MRSA infection.

    PubMed

    Faria, Nuno A; Oliveira, Duarte C; Westh, Henrik; Monnet, Dominique L; Larsen, Anders R; Skov, Robert; de Lencastre, Hermínia

    2005-04-01

    Strict infection control measures introduced during the 1970s have kept the incidence of methicillin-resistant Staphylococcus aureus (MRSA) infections extremely low in Denmark. Nevertheless, similarly to other countries, MRSA infections began to appear in the community in the late 1990s. A nationwide surveillance program has collected and stored all MRSA isolates since 1988 and, since 1999, clinical information has been also recorded. We used this information and isolates in a detailed epidemiological and molecular analysis of the 81 MRSA infections identified in Denmark in 2001. MRSA isolates were characterized by pulsed-field gel electrophoresis (PFGE), spa typing, multilocus sequence typing, and SCCmec typing. Comparison of the 45 community-onset MRSA (CO-MRSA) infections with the 36 hospital-acquired MRSA (HA-MRSA) infections showed several striking contrasts. Most CO-MRSA were recovered from skin and soft tissue infections caused by isolates carrying the Panton-Valentine leucocidin toxin genes, and the majority (84%) of isolates belonged to a single clonal type, ST80-IV, which has been found in the community in other European countries. Clone ST80-IV could be traced in Denmark back to 1993. ST80-IV was rarely found in HA-MRSA infections, which belonged to a large number of clonal types, including some pandemic MRSA clones. The low number of HA-MRSA infections and the diversity of MRSA clones in Danish hospitals may be the result of successful infection control measures that prevent spread of clones in hospitals. The mechanism of spread of the ST80-IV clone in the Danish community is not known, and new control measures are needed to control further spread of this and other CA-MRSA clones. PMID:15815005

  6. Epidemiology of Emerging Methicillin-Resistant Staphylococcus aureus (MRSA) in Denmark: a Nationwide Study in a Country with Low Prevalence of MRSA Infection

    PubMed Central

    Faria, Nuno A.; Oliveira, Duarte C.; Westh, Henrik; Monnet, Dominique L.; Larsen, Anders R.; Skov, Robert; de Lencastre, Hermínia

    2005-01-01

    Strict infection control measures introduced during the 1970s have kept the incidence of methicillin-resistant Staphylococcus aureus (MRSA) infections extremely low in Denmark. Nevertheless, similarly to other countries, MRSA infections began to appear in the community in the late 1990s. A nationwide surveillance program has collected and stored all MRSA isolates since 1988 and, since 1999, clinical information has been also recorded. We used this information and isolates in a detailed epidemiological and molecular analysis of the 81 MRSA infections identified in Denmark in 2001. MRSA isolates were characterized by pulsed-field gel electrophoresis (PFGE), spa typing, multilocus sequence typing, and SCCmec typing. Comparison of the 45 community-onset MRSA (CO-MRSA) infections with the 36 hospital-acquired MRSA (HA-MRSA) infections showed several striking contrasts. Most CO-MRSA were recovered from skin and soft tissue infections caused by isolates carrying the Panton-Valentine leucocidin toxin genes, and the majority (84%) of isolates belonged to a single clonal type, ST80-IV, which has been found in the community in other European countries. Clone ST80-IV could be traced in Denmark back to 1993. ST80-IV was rarely found in HA-MRSA infections, which belonged to a large number of clonal types, including some pandemic MRSA clones. The low number of HA-MRSA infections and the diversity of MRSA clones in Danish hospitals may be the result of successful infection control measures that prevent spread of clones in hospitals. The mechanism of spread of the ST80-IV clone in the Danish community is not known, and new control measures are needed to control further spread of this and other CA-MRSA clones. PMID:15815005

  7. First description of PVL-positive methicillin-resistant Staphylococcus aureus (MRSA) in wild boar meat.

    PubMed

    Kraushaar, Britta; Fetsch, Alexandra

    2014-09-01

    Staphylococcus aureus is an important food-borne pathogen due to the ability of enterotoxigenic strains to produce staphylococcal enterotoxins (SEs) in food. Methicillin-resistant S. aureus (MRSA) is also an important pathogen for humans, causing severe and hard to treat diseases in hospitals and in the community due to its multiresistance against antimicrobials. In particular, strains harbouring genes encoding for the Panton-Valentine leukocidin (PVL) toxin are of concern from a public health perspective as they are usually capable of causing severe skin and soft tissue infections (sSSTIs) and occasionally necrotizing pneumonia which is associated with high mortality. This is the first report on the detection of MRSA with genes encoding for PVL in wild boar meat. Among the 28 MRSA isolated from wild boar meat in the course of a national monitoring programme in Germany, seven harboured PVL-encoding genes. Six of the isolates were identical according to the results of spa-, MLST-, microarray- and PFGE-typing. They could be assigned to the epidemic MRSA clone USA300. Epidemiological investigations revealed that people handling the food were the most likely common source of contamination with these MRSA. These findings call again for suitable hygienic measures at all processing steps of the food production chain. The results of the study underline that monitoring along the food chain is essential to closely characterise the total burden of MRSA for public health.

  8. First description of PVL-positive methicillin-resistant Staphylococcus aureus (MRSA) in wild boar meat.

    PubMed

    Kraushaar, Britta; Fetsch, Alexandra

    2014-09-01

    Staphylococcus aureus is an important food-borne pathogen due to the ability of enterotoxigenic strains to produce staphylococcal enterotoxins (SEs) in food. Methicillin-resistant S. aureus (MRSA) is also an important pathogen for humans, causing severe and hard to treat diseases in hospitals and in the community due to its multiresistance against antimicrobials. In particular, strains harbouring genes encoding for the Panton-Valentine leukocidin (PVL) toxin are of concern from a public health perspective as they are usually capable of causing severe skin and soft tissue infections (sSSTIs) and occasionally necrotizing pneumonia which is associated with high mortality. This is the first report on the detection of MRSA with genes encoding for PVL in wild boar meat. Among the 28 MRSA isolated from wild boar meat in the course of a national monitoring programme in Germany, seven harboured PVL-encoding genes. Six of the isolates were identical according to the results of spa-, MLST-, microarray- and PFGE-typing. They could be assigned to the epidemic MRSA clone USA300. Epidemiological investigations revealed that people handling the food were the most likely common source of contamination with these MRSA. These findings call again for suitable hygienic measures at all processing steps of the food production chain. The results of the study underline that monitoring along the food chain is essential to closely characterise the total burden of MRSA for public health. PMID:25016468

  9. Comparison of the BD GeneOhm Methicillin-Resistant Staphylococcus aureus (MRSA) PCR Assay to Culture by Use of BBL CHROMagar MRSA for Detection of MRSA in Nasal Surveillance Cultures from Intensive Care Unit Patients▿

    PubMed Central

    Snyder, James W.; Munier, Gina K.; Johnson, Charles L.

    2010-01-01

    This study compared the BD GeneOhm methicillin-resistant Staphylococcus aureus (MRSA) real-time PCR assay to culture by the use of BBL CHROMagar MRSA for the detection of MRSA in 627 nasal surveillance specimens collected from intensive care unit (ICU) patients. The PCR assay had a sensitivity, specificity, positive predictive value, and negative predictive value of 100%, 96.7%, 70.3%, and 100%, respectively. Nine of 19 false-positive PCR specimens grew methicillin-susceptible S. aureus (MSSA) from broth enrichment culture, of which two demonstrated evidence of mecA gene dropout. Compared to culture by the use of BBL CHROMagar MRSA, the BD GeneOhm MRSA PCR assay demonstrated sensitivity and specificity above 95% for the detection of MRSA nasal colonization and provided shorter turnaround time in generating positive and negative final results. PMID:20181916

  10. Detection of methicillin resistant Staphylococcus aureus (MRSA) from recreational beach using the mecA gene

    NASA Astrophysics Data System (ADS)

    Zulkifli, Aisya; Ahmad, Asmat

    2015-09-01

    Water samples were collected in triplicates from three different locations choosen from the recreational beach of Teluk Kemang, Port Dickson as sampling station including main area of recreation activity for the public. Bacteria were isolated from the water and cultured. Out of 286 presumptive Staphylococcus aureus enumerated by using culture method, only 4 (1.4 %) confirmed as Meticillin Resistant S. aureus (MRSA) based on PCR detection of mecA gene. Interestingly, all of MRSA detections were found at the main area of recreational activity. Our results suggested that public beaches may be reservoir for transmission of MRSA to beach visitors and PCR using the mecA gene is the fastest way to detect this pathogenic bacteria.

  11. Methicillin-resistant Staphylococcus aureus (MRSA) among dental patients: a problem for infection control in dentistry?

    PubMed

    Zimmerli, Melanie; Widmer, Andreas F; Dangel, Marc; Filippi, Andreas; Frei, Reno; Meyer, Jürg

    2009-12-01

    We assessed the frequency of carriers of methicillin-resistant Staphylococcus aureus (MRSA) among 500 dental patients of a university clinic. From each participant, two specimens were taken from the anterior nares and the pharynx and analysed by culture. The participants completed a questionnaire on possible risk factors of MRSA infection. Two hundred ten individuals carried S. aureus, 90 in the nares only, 51 in the throat only and 69 in nares and throat. Isolates of 208 patients were methicillin-sensitive; two isolates were methicillin-resistant, both carried in the throat exclusively. In conclusion, the frequency of nasal and/or throat carriers of MRSA among dental patients was low and suggests few opportunities of exposure in the dental clinic assessed.

  12. Staphylococcus aureus and MRSA Growth and Biofilm Formation after Treatment with Antibiotics and SeNPs.

    PubMed

    Cihalova, Kristyna; Chudobova, Dagmar; Michalek, Petr; Moulick, Amitava; Guran, Roman; Kopel, Pavel; Adam, Vojtech; Kizek, Rene

    2015-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a dangerous pathogen resistant to β-lactam antibiotics. Due to its resistance, it is difficult to manage the infections caused by this strain. We examined this issue in terms of observation of the growth properties and ability to form biofilms in sensitive S. aureus and MRSA after the application of antibiotics (ATBs)-ampicillin, oxacillin and penicillin-and complexes of selenium nanoparticles (SeNPs) with these ATBs. The results suggest the strong inhibition effect of SeNPs in complexes with conventional ATBs. Using the impedance method, a higher disruption of biofilms was observed after the application of ATB complexes with SeNPs compared to the group exposed to ATBs without SeNPs. The biofilm formation was intensely inhibited (up to 99%±7% for S. aureus and up to 94%±4% for MRSA) after application of SeNPs in comparison with bacteria without antibacterial compounds whereas ATBs without SeNPs inhibited S. aureus up to 79%±5% and MRSA up to 16%±2% only. The obtained results provide a basis for the use of SeNPs as a tool for the treatment of bacterial infections, which can be complicated because of increasing resistance of bacteria to conventional ATB drugs. PMID:26501270

  13. Staphylococcus aureus and MRSA Growth and Biofilm Formation after Treatment with Antibiotics and SeNPs

    PubMed Central

    Cihalova, Kristyna; Chudobova, Dagmar; Michalek, Petr; Moulick, Amitava; Guran, Roman; Kopel, Pavel; Adam, Vojtech; Kizek, Rene

    2015-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a dangerous pathogen resistant to β-lactam antibiotics. Due to its resistance, it is difficult to manage the infections caused by this strain. We examined this issue in terms of observation of the growth properties and ability to form biofilms in sensitive S. aureus and MRSA after the application of antibiotics (ATBs)—ampicillin, oxacillin and penicillin—and complexes of selenium nanoparticles (SeNPs) with these ATBs. The results suggest the strong inhibition effect of SeNPs in complexes with conventional ATBs. Using the impedance method, a higher disruption of biofilms was observed after the application of ATB complexes with SeNPs compared to the group exposed to ATBs without SeNPs. The biofilm formation was intensely inhibited (up to 99% ± 7% for S. aureus and up to 94% ± 4% for MRSA) after application of SeNPs in comparison with bacteria without antibacterial compounds whereas ATBs without SeNPs inhibited S. aureus up to 79% ± 5% and MRSA up to 16% ± 2% only. The obtained results provide a basis for the use of SeNPs as a tool for the treatment of bacterial infections, which can be complicated because of increasing resistance of bacteria to conventional ATB drugs. PMID:26501270

  14. Methicillin resistant Staphylococcus aureus (MRSA) carriage in different free-living wild animal species in Spain.

    PubMed

    Porrero, M Concepción; Mentaberre, Gregorio; Sánchez, Sergio; Fernández-Llario, Pedro; Gómez-Barrero, Susana; Navarro-Gonzalez, Nora; Serrano, Emmanuel; Casas-Díaz, Encarna; Marco, Ignasi; Fernández-Garayzabal, José-Francisco; Mateos, Ana; Vidal, Dolors; Lavín, Santiago; Domínguez, Lucas

    2013-10-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a life-threatening pathogen in humans and its presence in animals is a public health concern. The aim of this study was to measure the prevalence of MRSA in free-living wild animals. Samples from red deer (n=273), Iberian ibex (n=212), Eurasian Griffon vulture (n=40) and wild boar (n=817) taken from different areas in Spain between June 2008 and November 2011 were analyzed. Characterization of the isolates was performed by spa typing, multi-locus sequence typing (MLST) and antimicrobial susceptibility testing. A low prevalence of MRSA was found with 13 isolates obtained from 12 animals (0.89%; 95% CI: 0.46-1.56). All MRSA sequence types belonged to ST398 (t011 and t1451) and ST1 (t127). Genotypes and antimicrobial susceptibility patterns (tetracycline resistance in ST398 and clindamycin-erythromycin-tetracycline resistance in ST1) suggest that the MRSA found probably originated in livestock (ST398) or humans (ST1). This is the first report of MRSA carriers in free-living wild animals in Europe. Although our data showed that MRSA prevalence is currently low, free-living wild animals might act as reservoir and represent a potential risk for human health.

  15. Anti-methicillin-resistant Staphylococcus aureus (MRSA) substance from the marine bacterium Pseudomonas sp. UJ-6.

    PubMed

    Lee, Dae-Sung; Eom, Sung-Hwan; Jeong, Seong-Yun; Shin, Hee Jae; Je, Jae-Young; Lee, Eun-Woo; Chung, Yong-Hyun; Kim, Young-Mog; Kang, Chang-Keun; Lee, Myung-Suk

    2013-03-01

    A multivalent approach to discover a novel antibiotic substance against methicillin-resistant Staphylococcus aureus (MRSA), a marine bacterium, UJ-6, exhibiting an antibacterial activity against MRSA was isolated from seawater. The isolated strain was identified to be Pseudomonas sp. by the morphology, biochemical, and genetical analyses. The ethyl acetate extract of Pseudomonas sp. UJ-6 culture showed significant ant-MRSA activity. Bioassay-guided isolation of the extract using a growth inhibitory assay led to the isolation and identification of an active compound exhibiting anti-MRSA activity. Based on the analyses of the physicochemical and spectroscopic data including nuclear magnetic resonance and mass, the compound was identified to be 1-acetyl-beta-carboline. The minimum inhibitory concentration (MIC) of the compound was determined to be in a range of 32-128 μg/ml against MRSA strains. The MIC values against MRSA were superior or equal to those of other natural compounds such as catechins, suggesting that 1-acetyl-beta-carboline would be a good candidate in applications of the treatment of MRSA infection.

  16. Comparison of the BD GeneOhm Methicillin-Resistant Staphylococcus aureus (MRSA) PCR Assay to Culture by Use of BBL CHROMagar MRSA for Detection of MRSA in Nasal Surveillance Cultures from an At-Risk Community Population▿

    PubMed Central

    Farley, Jason E.; Stamper, Paul D.; Ross, Tracy; Cai, Mian; Speser, Sharon; Carroll, Karen C.

    2008-01-01

    We compared the BD GeneOhm methicillin-resistant Staphylococcus aureus (MRSA) PCR assay to culture with BBL CHROMagar MRSA for nasal surveillance among 602 arrestees from the Baltimore City Jail. The sensitivity and specificity were 88.5% and 91.0%, respectively, and after secondary analysis using enrichment broth, they were 89.0% and 91.7%, respectively. Twenty-three of 42 false-positive PCR lysates contained methicillin-susceptible S. aureus. PMID:18057129

  17. Methicillin-resistant Staphylococcus aureus (MRSA) in slaughtered pigs and abattoir workers in Italy.

    PubMed

    Normanno, Giovanni; Dambrosio, Angela; Lorusso, Vanessa; Samoilis, Georgios; Di Taranto, Pietro; Parisi, Antonio

    2015-10-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a pathogen present in the hospital environment (HA-MRSA), in the community (CA-MRSA) and in livestock, including pigs (LA-MRSA). MRSA may enter the human food chain during slaughtering and may infect humans coming into direct contact with pigs or pork products. This study aimed to determine the prevalence and characteristics of MRSA isolated from pigs and workers at industrial abattoirs in southern Italy. A total of 215 pig nasal swabs were screened for the presence of MRSA using PCR. An MRSA isolate was detected from each mecA/nuc PCR-positive sample and characterized by spa-typing, Multi-Locus Sequence Typing, SCC-mec and Panton-Valentine Leukocidin (PVL), and also tested for the production of staphylococcal enterotoxins (SEs). Eighty-one MRSA isolates (37.6%) were obtained from the 215 pig nasal swabs; 37 of these isolates were further characterized, and showed 18 different spa-types and 8 different STs. The most frequently recovered STs were ST398 (CC398-t034, t011, t899, t1939 - 43.2%) followed by ST8 (CC8-t008, t064, t2953, t5270 - 24.3%) and ST1 (CC1-t127, t174, t2207 - 10.8%). Nine MRSA isolates were obtained from the 113 human swabs; the isolates showed 5 different spa-types and 5 different STs, including the novel ST2794 (t159). The most representative STs recovered were ST1 (CC1-t127) and ST398 (CC398-t034) (33.3%). None of the MRSA isolates showed the ability to produce SEs and PVL and all resulted resistant to two or more classes of antimicrobials. This study shows the great genetic diversity of MRSA strains in slaughtered pigs and in abattoir employees in Italy, and clearly demonstrates the need for improved hygiene standards to reduce the risk of occupational and food-borne infection linked to the handling/consumption of raw pork containing MRSA.

  18. Validity of ICD-9-CM Coding for Identifying Incident Methicillin-Resistant Staphylococcus aureus (MRSA) Infections: Is MRSA Infection Coded as a Chronic Disease?

    PubMed Central

    Schweizer, Marin L.; Eber, Michael R.; Laxminarayan, Ramanan; Furuno, Jon P.; Popovich, Kyle J.; Hota, Bala; Rubin, Michael A.; Perencevich, Eli N.

    2013-01-01

    BACKGROUND AND OBJECTIVE Investigators and medical decision makers frequently rely on administrative databases to assess methicillin-resistant Staphylococcus aureus (MRSA) infection rates and outcomes. The validity of this approach remains unclear. We sought to assess the validity of the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) code for infection with drug-resistant microorganisms (V09) for identifying culture-proven MRSA infection. DESIGN Retrospective cohort study. METHODS All adults admitted to 3 geographically distinct hospitals between January 1, 2001, and December 31, 2007, were assessed for presence of incident MRSA infection, defined as an MRSA-positive clinical culture obtained during the index hospitalization, and presence of the V09 ICD-9-CM code. The k statistic was calculated to measure the agreement between presence of MRSA infection and assignment of the V09 code. Sensitivities, specificities, positive predictive values, and negative predictive values were calculated. RESULTS There were 466,819 patients discharged during the study period. Of the 4,506 discharged patients (1.0%) who had the V09 code assigned, 31% had an incident MRSA infection, 20% had prior history of MRSA colonization or infection but did not have an incident MRSA infection, and 49% had no record of MRSA infection during the index hospitalization or the previous hospitalization. The V09 code identified MRSA infection with a sensitivity of 24% (range, 21%–34%) and positive predictive value of 31% (range, 22%–53%). The agreement between assignment of the V09 code and presence of MRSA infection had a κ coefficient of 0.26 (95% confidence interval, 0.25–0.27). CONCLUSIONS In its current state, the ICD-9-CM code V09 is not an accurate predictor of MRSA infection and should not be used to measure rates of MRSA infection. PMID:21460469

  19. Effects of Subinhibitory Concentrations of Ceftaroline on Methicillin-Resistant Staphylococcus aureus (MRSA) Biofilms.

    PubMed

    Lázaro-Díez, María; Remuzgo-Martínez, Sara; Rodríguez-Mirones, Cristina; Acosta, Felix; Icardo, Jose M; Martínez-Martínez, Luis; Ramos-Vivas, José

    2016-01-01

    Ceftaroline (CPT) is a novel cephalosporin with in vitro activity against Staphylococcus aureus. Ceftaroline exhibits a level of binding affinity for PBPs in S. aureus including PBP2a of methicillin-resistant S. aureus (MRSA). The aims of this study were to investigate the morphological, physiological and molecular responses of MRSA clinical strains and MRSA biofilms to sub-MICs (1/4 and 1/16 MIC) of ceftaroline by using transmission, scanning and confocal microscopy. We have also used quantitative Real-Time PCR to study the effect of sub-MICs of ceftaroline on the expression of the staphylococcal icaA, agrA, sarA and sasF genes in MRSA biofilms. In one set of experiments, ceftaroline was able to inhibit biofilm formation in all strains tested at MIC, however, a strain dependent behavior in presence of sub-MICs of ceftaroline was shown. In a second set of experiments, destruction of preformed biofilms by addition of ceftaroline was evaluated. Ceftaroline was able to inhibit biofilm formation at MIC in all strains tested but not at the sub-MICs. Destruction of preformed biofilms was strain dependent because the biofilm formed by a matrix-producing strain was resistant to a challenge with ceftaroline at MIC, whereas in other strains the biofilm was sensitive. At sub-MICs, the impact of ceftaroline on expression of virulence genes was strain-dependent at 1/4 MIC and no correlation between ceftaroline-enhanced biofilm formation and gene regulation was established at 1/16 MIC. Our findings suggest that sub-MICs of ceftaroline enhance bacterial attachment and biofilm formation by some, but not all, MRSA strains and, therefore, stress the importance of maintaining effective bactericidal concentrations of ceftaroline to fight biofilm-MRSA related infections.

  20. Effects of Subinhibitory Concentrations of Ceftaroline on Methicillin-Resistant Staphylococcus aureus (MRSA) Biofilms

    PubMed Central

    Rodríguez-Mirones, Cristina; Acosta, Felix; Icardo, Jose M.; Martínez-Martínez, Luis; Ramos-Vivas, José

    2016-01-01

    Ceftaroline (CPT) is a novel cephalosporin with in vitro activity against Staphylococcus aureus. Ceftaroline exhibits a level of binding affinity for PBPs in S. aureus including PBP2a of methicillin-resistant S. aureus (MRSA). The aims of this study were to investigate the morphological, physiological and molecular responses of MRSA clinical strains and MRSA biofilms to sub-MICs (1/4 and 1/16 MIC) of ceftaroline by using transmission, scanning and confocal microscopy. We have also used quantitative Real-Time PCR to study the effect of sub-MICs of ceftaroline on the expression of the staphylococcal icaA, agrA, sarA and sasF genes in MRSA biofilms. In one set of experiments, ceftaroline was able to inhibit biofilm formation in all strains tested at MIC, however, a strain dependent behavior in presence of sub-MICs of ceftaroline was shown. In a second set of experiments, destruction of preformed biofilms by addition of ceftaroline was evaluated. Ceftaroline was able to inhibit biofilm formation at MIC in all strains tested but not at the sub-MICs. Destruction of preformed biofilms was strain dependent because the biofilm formed by a matrix-producing strain was resistant to a challenge with ceftaroline at MIC, whereas in other strains the biofilm was sensitive. At sub-MICs, the impact of ceftaroline on expression of virulence genes was strain-dependent at 1/4 MIC and no correlation between ceftaroline-enhanced biofilm formation and gene regulation was established at 1/16 MIC. Our findings suggest that sub-MICs of ceftaroline enhance bacterial attachment and biofilm formation by some, but not all, MRSA strains and, therefore, stress the importance of maintaining effective bactericidal concentrations of ceftaroline to fight biofilm-MRSA related infections. PMID:26800524

  1. Contamination of environmental surfaces by methicillin-resistant Staphylococcus aureus (MRSA) in rooms of inpatients with MRSA-positive body sites.

    PubMed

    Kurashige, E Jessica Ohashi; Oie, Shigeharu; Furukawa, H

    2016-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) can contaminate environmental surfaces that are frequently touched by the hands of patients with MRSA colonization/infection. There have been many studies in which the presence or absence of MRSA contamination was determined but no studies in which MRSA contamination levels were also evaluated in detail. We evaluated MRSA contamination of environmental surfaces (overbed tables, bed side rails, and curtains) in the rooms of inpatients from whom MRSA was isolated via clinical specimens. We examined the curtains within 7-14 days after they had been newly hung. The environmental surfaces were wiped using gauze (molded gauze for wiping of surface bacteria; 100% cotton, 4cm×8cm) moistened with sterile physiological saline. The MRSA contamination rate and mean counts (range) were 25.0% (6/24 samples) and 30.6 (0-255)colony-forming units (cfu)/100cm(2), respectively, for the overbed tables and 31.6% (6/19 samples) and 159.5 (0-1620)cfu/100cm(2), respectively, for the bed side rails. No MRSA was detected in 24 curtain samples. The rate of MRSA contamination of environmental surfaces was high for the overbed tables and bed side rails but low for the curtains. Therefore, at least until the 14th day of use, frequent disinfection of curtains may be not necessary.

  2. Synergism between Medihoney and rifampicin against methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Müller, Patrick; Alber, Dagmar G; Turnbull, Lynne; Schlothauer, Ralf C; Carter, Dee A; Whitchurch, Cynthia B; Harry, Elizabeth J

    2013-01-01

    Skin and chronic wound infections caused by highly antibiotic resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) are an increasing and urgent health problem worldwide, particularly with sharp increases in obesity and diabetes. New Zealand manuka honey has potent broad-spectrum antimicrobial activity, has been shown to inhibit the growth of MRSA strains, and bacteria resistant to this honey have not been obtainable in the laboratory. Combinational treatment of chronic wounds with manuka honey and common antibiotics may offer a wide range of advantages including synergistic enhancement of the antibacterial activity, reduction of the effective dose of the antibiotic, and reduction of the risk of antibiotic resistance. The aim of this study was to investigate the effect of Medihoney in combination with the widely used antibiotic rifampicin on S. aureus. Using checkerboard microdilution assays, time-kill curve experiments and agar diffusion assays, we show a synergism between Medihoney and rifampicin against MRSA and clinical isolates of S. aureus. Furthermore, the Medihoney/rifampicin combination stopped the appearance of rifampicin-resistant S. aureus in vitro. Methylglyoxal (MGO), believed to be the major antibacterial compound in manuka honey, did not act synergistically with rifampicin and is therefore not the sole factor responsible for the synergistic effect of manuka honey with rifampicin. Our findings support the idea that a combination of honey and antibiotics may be an effective new antimicrobial therapy for chronic wound infections. PMID:23469049

  3. MRSA (For Parents)

    MedlinePlus

    ... Story" 5 Things to Know About Zika & Pregnancy MRSA KidsHealth > For Parents > MRSA Print A A A ... and most infections can be treated easily. About MRSA MRSA stands for methicillin-resistant Staphylococcus aureus, a ...

  4. Three-Way Comparison of BBL CHROMagar MRSA II, MRSASelect, and Spectra MRSA for Detection of Methicillin-Resistant Staphylococcus aureus Isolates in Nasal Surveillance Cultures

    PubMed Central

    Renzi, Pamela B.; Koch, Kim M.; Wissel, Carol M.

    2013-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of hospital-acquired and life-threatening infections. Active surveillance programs for MRSA utilize either molecular or culture-based methods. A prospective study was performed to compare the performance of selective and differential chromogenic media, BBL CHROMagar MRSA II (CMRSA II; BD Diagnostics, Sparks, MD), MRSASelect (Bio-Rad Laboratories, Redmond, WA), and Spectra MRSA (Remel, Lenexa, KS), for the detection of MRSA in nasal swab specimens. A total of 515 compliant remnant nasal swab specimens were sequentially used to inoculate BBL Trypticase soy agar with 5% sheep blood (TSA II) and each chromogenic medium. After 24 h of incubation, colony color reactions and morphology on chromogenic media were compared to suspicious colonies on nonselective TSA II. MRSA on TSA II was confirmed by Gram staining, a coagulase test, and a cefoxitin disk test. The overall prevalence of MRSA and methicillin-susceptible S. aureus (MSSA) on TSA II was 12.4% (64/515) and 9.7% (50/515), respectively. When each chromogenic medium was compared to the standard culture method, the sensitivity and specificity, respectively, were as follows: CMRSA II, 87.7% and 98.6%; MRSASelect, 89.0% and 93.4%; and Spectra MRSA, 83.6% and 92.1%. The positive predictive values were highest for CMRSA II (91.4%), followed by MRSASelect (69.1%) and Spectra MRSA (63.5%). False-positive results on chromogenic media were mainly due to color interpretation. The negative predictive values for all three media were greater than 97%. In conclusion, CMRSA II gave the best overall results for detecting MRSA from nasal specimens. PMID:23135930

  5. Evaluation of a New Selective Medium, BD BBL CHROMagar MRSA II, for Detection of Methicillin-Resistant Staphylococcus aureus in Stool Specimens ▿

    PubMed Central

    Havill, Nancy L.; Boyce, John M.

    2010-01-01

    We compared the recovery of methicillin-resistant Staphylococcus aureus (MRSA) on a new selective chromogenic agar, BD BBL CHROMagar MRSA II (CMRSAII), to that on traditional culture media with 293 stool specimens. The recovery of MRSA was greater on the CMRSAII agar. Screening of stool samples can identify patients who were previously unknown carriers of MRSA. PMID:20392908

  6. Inactivating Methicillin Resistant Staphylococcus aureus (MRSA) and Other Pathogens by Bacteriocins OR-7 and E 50-52.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Worldwide, reports document the increasing frequency of methicillin resistant Staphylococcus aureus (MRSA) infections. Other human pathogens are recognized as unresponsive to antibiotics of last resort. These previously treatable infections now account for increased numbers of human disease and de...

  7. Inactivating Methicillin Resistant Staphylococcus aureus (MRSA) and other Pathogens by Bacteriocins OR-7 and E 50-52.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Worldwide, reports document the increasing frequency of methicillin resistant Staphylococcus aureus (MRSA) infections. Other human pathogens are recognized as unresponsive to antibiotics of last resort. These previously treatable infections now account for increased numbers of human disease and de...

  8. Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) isolates of swine origin form robust biofilms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methicillin-resistant Staphylococcus aureus (MRSA) colonization of livestock animals is common and prevalence rates for pigs have been reported to be as high as 49%. One hypothesis to explain the high prevalence of MRSA in swine herds is the ability of these organisms to exist as biofilms. To invest...

  9. Prevalence and molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) among subjects working on bovine dairy farms.

    PubMed

    Antoci, Eugenio; Pinzone, Marilia Rita; Nunnari, Giuseppe; Stefani, Stefania; Cacopardo, Bruno

    2013-06-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of healthcare-associated infections worldwide and has recently been identified as an emerging pathogen in livestock and companion animals. Livestock-associated MRSA (LA-MRSA) may be responsible for increased rates of colonization and/or infection among people working on farms. We evaluated the prevalence and molecular characteristics of MRSA among dairy farmers in the province of Ragusa, South-Eastern Sicily, their animals and bulk tank milk samples. A surprisingly high number of samples tested positive for MRSA: 36% of human nasal swabs, 61% of bovine nasal swabs and 44% of bulk tank milk samples. MRSA carrier prevalence in humans significantly correlated with the percentage of positive cows on the farm, the number of livestock units and the presence of consensual positive bulk tank milk samples. Prospective studies are needed to investigate MRSA transmission between animals and humans and implement preventive strategies.

  10. Prevalence and molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) in organic pig herds in The Netherlands.

    PubMed

    van de Vijver, L P L; Tulinski, P; Bondt, N; Mevius, D; Verwer, C

    2014-08-01

    The prevalence of the methicillin-resistant Staphylococcus aureus (MRSA) among conventional pig herds in the Netherlands is high (around 71%). Nevertheless, information about the prevalence of MRSA among organic pig herds is lacking. Here, we report a study on 24 of the 49 organic pig herds in the Netherlands. The prevalence of MRSA positive herds showed to be 21%. The genetic characteristics of the MRSA isolates were similar to MRSA CC398 described in conventional pigs except one exceptional HA-MRSA CC30 found in one herd, which was presumably caused by human to animal transmission. This resulted in a prevalence of MRSA CC398 in the organic herds of 16.7%.

  11. Virulence strategies of the dominant USA300 lineage of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA).

    PubMed

    Thurlow, Lance R; Joshi, Gauri S; Richardson, Anthony R

    2012-06-01

    Methicillin-resistant Staphylococcus aureus (MRSA) poses a serious threat to worldwide health. Historically, MRSA clones have strictly been associated with hospital settings, and most hospital-associated MRSA (HA-MRSA) disease resulted from a limited number of virulent clones. Recently, MRSA has spread into the community causing disease in otherwise healthy people with no discernible contact with healthcare environments. These community-associated MRSA clones (CA-MRSA) are phylogenetically distinct from traditional HA-MRSA clones, and CA-MRSA strains seem to exhibit hypervirulence and more efficient host : host transmission. Consequently, CA-MRSA clones belonging to the USA300 lineage have become dominant sources of MRSA infections in North America. The rise of this successful USA300 lineage represents an important step in the evolution of emerging pathogens and a great deal of effort has been exerted to understand how these clones evolved. Here, we review much of the recent literature aimed at illuminating the source of USA300 success and broadly categorize these findings into three main categories: newly acquired virulence genes, altered expression of common virulence determinants and alterations in protein sequence that increase fitness. We argue that none of these evolutionary events alone account for the success of USA300, but rather their combination may be responsible for the rise and spread of CA-MRSA.

  12. Significant antibacterial activity and synergistic effects of camel lactoferrin with antibiotics against methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Redwan, Elrashdy M; El-Baky, Nawal Abd; Al-Hejin, Ahmed M; Baeshen, Mohammed N; Almehdar, Hussein A; Elsaway, Abdulrahman; Gomaa, Abu-Bakr M; Al-Masaudi, Saad Berki; Al-Fassi, Fahad A; AbuZeid, Isam Eldin; Uversky, Vladimir N

    2016-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) causes major healthcare problems in many countries, as it is present as several hospital- and community-associated strains. Hospital-associated MRSA is one of the most prevalent nosocomial pathogens throughout the world and infections caused by community-acquired MRSA are rising. This emphasizes the need for new and efficient anti-MRSA agents. We evaluated the antibacterial effects of camel lactoferrin (cLf) and human lactoferrin (hLf) alone and in combination with several antibiotics against MRSA. Antimicrobials were tested against MRSA and an S. aureus control strain by the agar disc diffusion method. The minimum inhibitory concentration (MIC) was determined for antimicrobials by the broth microdilution method. Synergy between cLf or hLf and antibiotics was examined by checkerboard and time-kill assays. The agar disc diffusion assay showed that MRSA growth was inhibited by cLf at 0.25-3 mg/ml and hLf at 1-3 mg/ml. cLf demonstrated 3 times higher inhibitory activity against MRSA than hLf in terms of MIC values (250 vs. 750 μg/ml, respectively). Biotinylated cLf was recognized by two membrane proteins of MRSA, 66-67 KDa. Combinations of cLf or hLf and oxacillin or vancomycin at sub-MIC levels enhanced in vitro antibacterial activity against MRSA compared with each agent alone. PMID:27130281

  13. Immunological control of methicillin-resistant Staphylococcus aureus (MRSA) infection in an immunodeficient murine model of thermal injuries

    PubMed Central

    Katakura, T; Yoshida, T; Kobayashi, M; Herndon, D N; Suzuki, F

    2005-01-01

    Staphylococcus aureus, especially methicillin-resistant S. aureus (MRSA), is a major cause of sepsis in patients who are immunosuppressed by their burns. In this study, an immunological regulation of MRSA infection was attempted in a mouse model of thermal injury. SCIDbg mice were resistant to MRSA infection, while SCIDbgMN mice (SCIDbg mice depleted of neutrophils and macrophages (Mφ)) were susceptible to the same infection. Also, thermally injured SCIDbg mice were shown to be susceptible to MRSA infection. On the other hand, the resistance of SCIDbgMN mice to the infection was completely recovered after an inoculation with Mφ from normal mice. However, anti-MRSA resistance was not shown in SCIDbgMN mice inoculated with Mφ from thermally injured mice. Mφ from MRSA-infected thermally injured mice were identified as alternatively activated Mφ, and Mφ from MRSA-infected unburned mice were characterized as classically activated Mφ. Mφ from thermally injured SCIDbg mice previously treated with 2-carboxyethylgermanium sesquioxide (Ge-132) protected SCIDbgMN mice against MRSA infection. Ge-132 has been described as an inhibitor of alternatively activated Mφ generation. These results suggest that MRSA infection in thermally injured patients is controlled immunologically through the induction of anti-MRSA effector cells and elimination of burn-associated alternatively activated Mφ, which are cells that inhibit the generation of classically activated Mφ. PMID:16297152

  14. Performance of 3 real-time PCR assays for direct detection of Staphylococcus aureus and MRSA from clinical samples.

    PubMed

    Mehta, Maitry S; McClure, J T; Mangold, Kathy; Peterson, Lance R

    2015-11-01

    We compared 3 real-time PCR assays: off-label use of 2 commercial assays (BD-GeneOhm™ MRSA assay for methicillin-resistant Staphylococcus aureus [MRSA] detection and BD-GeneOhm StaphSR™ for MRSA and methicillin-susceptible S. aureus detection) and an in-house real-time PCR assay for detection of total S. aureus from clinical specimens. Testing was performed on 200 distinct specimens. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated using culture as the gold standard. The prevalence of S. aureus in the samples was 44.5%, and MRSA was 20%. For total S. aureus, the StaphSR-PCR and the in-house PCR assays had a sensitivity and specificity of 94.4% and 96.4% and 93.3% and 99.1%, respectively. For MRSA detection, the StaphSR and the BD GeneOhm assay had a sensitivity and specificity of 92.5% and 98.8% and 92.5% and 96.3%, respectively. This study demonstrates the potential use of tests like the StaphSR-PCR assay for rapid detection of S. aureus and MRSA directly from clinical specimens; however, culture follow-up would be needed to identify other potential pathogens in the specimen.

  15. Antimethicillin-resistant Staphylococcus aureus (MRSA) activity of 'pacific propolis' and isolated prenylflavanones.

    PubMed

    Raghukumar, Raghavendra; Vali, Leila; Watson, Dave; Fearnley, James; Seidel, Véronique

    2010-08-01

    The need to discover and develop alternative therapies to treat methicillin-resistant Staphylococcus aureus (MRSA) infections is timely. This study was undertaken to purify and identify some anti-MRSA constituents from propolis, a natural product from the beehive traditionally used in folk medicine for its antimicrobial properties. A crude extract of propolis originating from the Solomon Islands ('Pacific propolis') was screened, using an agar dilution assay, in vitro against 15 MRSA clinical isolates. Results revealed activity worthy of further investigation, and subsequent purification work on this crude extract afforded 23 fractions. Further purification of active fractions led to the isolation of compounds 1-4, characterized upon analysis of their spectroscopic data (1D- and 2D-NMR, MS) and by comparison with the literature, as the prenylflavanones propolin H (1), propolin G (2), propolin D (3), and propolin C (4). This study is the first to report the anti-MRSA activity of 'Pacific propolis' and the presence of prenylflavanones in the propolis sample selected. The anti-MRSA activity of propolin D (3) (MIC 8-16 mg/L) and propolin C (4) (MIC 8-32 mg/L) is reported for the first time.

  16. Phenotypic and genotypic characterization of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible Staphylococcus aureus (MSSA) from different sources in China.

    PubMed

    Chao, Guoxiang; Zhang, Xiaoping; Zhang, Xiaorong; Huang, Yao; Xu, Lan; Zhou, Liping; Yang, Weixia; Jiang, Yuan; Xue, Feng; Wu, Yantao

    2013-03-01

    A diverse collection of 261 Staphylococcus aureus strains from human, animal, food, and environmental sources were tested for the presence and type of SCCmec elements, antibiotic susceptibility to various antibiotics, and non-ß-lactam antibiotic resistance genes. About 18.39% (48/261) of strains were methicillin-resistant S. aureus (MRSA) including 29.75% (36/121) human strains of which 29 strains were hospital-acquired MRSA (HA-MRSA) and 7 strains were community-associated MRSA (CA-MRSA) and 19.67% (12/61) animal strains that all were CA-MRSA strains. The percentage of CA-MRSA strains from animals was significantly higher than that from human (p<0.01). Most of MRSA strains and a part of methicillin-susceptible S. aureus (MSSA) strains harbored unique combinations of non-ß-lactamase genes aac(6')/aph(2″), aph(3')-III, ant (4',4″), ermA, ermC, mrsA, tetM, and tetK. Antibiotic resistance genes were detected more frequently in HA-MRSA strains than in CA-MRSA strains (p<0.01). MRSA strains and MSSA strains had 22 and 39 antibiotic profiles to 15 tested antibiotics, respectively. The resistant proportion was higher in HA-MRSA strains than in CA-MSSA strains for various antibiotics, as well as higher in MRSA strains than in MSSA strains. Animal MRSA reservoirs (particularly pigs and cows) might represent an important source of human CA-MRSA. CA-MRSA strains might acquire more different resistance genes gradually, depending on the selective pressure of antibiotics in different regions or environments. CA-MRSA is not yet endemic in China, but could be prevalent in future, contributing to its acquiring more resistance genes and huge animal sources. Infection with multidrug-resistant MSSA strains acquired from food, animal, and human sources might also become a significant problem for human medicine, which warrants further study.

  17. Genotypic and phenotypic characteristics of Methicillin-resistant Staphylococcus aureus (MRSA) strains, isolated on three different geography locations.

    PubMed

    Ostojić, Maja; Hukić, Mirsada

    2015-08-04

    Staphylococcus aureus is a major cause of hospital-acquired infections worldwide. Increased frequency of methicillin-resistant Staphylococcus aureus (MRSA) in hospitalized patients and possibility of vancomycin resistance requires rapid and reliable characterization of isolates and control of MRSA spread in hospitals. Typing of isolates helps to understand the route of a hospital pathogen spread. The aim of this study was to investigate and compare genotypic and phenotypic characteristics of MRSA samples on three different geography locations. In addition, our aim was to evaluate three different methods of MRSA typing: spa-typing, agr-typing and GenoType MRSA.  We included 104 samples of MRSA, isolated in 3 different geographical locations in clinical hospitals in Zagreb, Mostar, and Heidelberg, during the period of six months. Genotyping and phenotyping were done by spa-typing, agr-typing and dipstick assay GenoType MRSA. We failed to type all our samples by spa-typing.  The most common spa-type in clinical hospital Zagreb was t041, in Mostar t001, and in Heidelberg t003.We analyzed 102/104 of our samples by agr-typing method. We did not find any agr-type IV in our locations. We analyzed all our samples by the dipstick assay GenoType MRSA. All isolates in our study were MRSA strains. In Zagreb there were no positive strains to PVL gene. In Mostar we have found 5/25 positive strains to PVL gene, in Heidelberg there was 1/49. PVL positive isolates were associated with spa-type t008 and agr-type I, thus, genetically, they were community-associated MRSA (CA-MRSA). Dipstick assay GenoType MRSA has demonstrated sufficient specificity, sensibility, simple performance and low cost, so we could introduce it to work in smaller laboratories. Using this method may expedite MRSA screening, thus preventing its spread in hospitals.

  18. Genotypic and phenotypic characteristics of Methicillin-resistant Staphylococcus aureus (MRSA) strains, isolated on three different geography locations

    PubMed Central

    Ostojić, Maja; Hukić, Mirsada

    2015-01-01

    Staphylococcus aureus is a major cause of hospital-acquired infections worldwide. Increased frequency of methicillin-resistant Staphylococcus aureus (MRSA) in hospitalized patients and possibility of vancomycin resistance requires rapid and reliable characterization of isolates and control of MRSA spread in hospitals. Typing of isolates helps to understand the route of a hospital pathogen spread. The aim of this study was to investigate and compare genotypic and phenotypic characteristics of MRSA samples on three different geography locations. In addition, our aim was to evaluate three different methods of MRSA typing: spa-typing, agr-typing and GenoType MRSA. We included 104 samples of MRSA, isolated in 3 different geographical locations in clinical hospitals in Zagreb, Mostar, and Heidelberg, during the period of six months. Genotyping and phenotyping were done by spa-typing, agr-typing and dipstick assay GenoType MRSA. We failed to type all our samples by spa-typing. The most common spa-type in clinical hospital Zagreb was t041, in Mostar t001, and in Heidelberg t003. We analyzed 102/104 of our samples by agr-typing method. We did not find any agr-type IV in our locations. We analyzed all our samples by the dipstick assay GenoType MRSA. All isolates in our study were MRSA strains. In Zagreb there were no positive strains to PVL gene. In Mostar we have found 5/25 positive strains to PVL gene, in Heidelberg there was 1/49. PVL positive isolates were associated with spa-type t008 and agr-type I, thus, genetically, they were community-associated MRSA (CA-MRSA). Dipstick assay GenoType MRSA has demonstrated sufficient specificity, sensibility, simple performance and low cost, so we could introduce it to work in smaller laboratories. Using this method may expedite MRSA screening, thus preventing its spread in hospitals. PMID:26295294

  19. Genotypic and phenotypic characteristics of Methicillin-resistant Staphylococcus aureus (MRSA) strains, isolated on three different geography locations.

    PubMed

    Ostojić, Maja; Hukić, Mirsada

    2015-01-01

    Staphylococcus aureus is a major cause of hospital-acquired infections worldwide. Increased frequency of methicillin-resistant Staphylococcus aureus (MRSA) in hospitalized patients and possibility of vancomycin resistance requires rapid and reliable characterization of isolates and control of MRSA spread in hospitals. Typing of isolates helps to understand the route of a hospital pathogen spread. The aim of this study was to investigate and compare genotypic and phenotypic characteristics of MRSA samples on three different geography locations. In addition, our aim was to evaluate three different methods of MRSA typing: spa-typing, agr-typing and GenoType MRSA.  We included 104 samples of MRSA, isolated in 3 different geographical locations in clinical hospitals in Zagreb, Mostar, and Heidelberg, during the period of six months. Genotyping and phenotyping were done by spa-typing, agr-typing and dipstick assay GenoType MRSA. We failed to type all our samples by spa-typing.  The most common spa-type in clinical hospital Zagreb was t041, in Mostar t001, and in Heidelberg t003.We analyzed 102/104 of our samples by agr-typing method. We did not find any agr-type IV in our locations. We analyzed all our samples by the dipstick assay GenoType MRSA. All isolates in our study were MRSA strains. In Zagreb there were no positive strains to PVL gene. In Mostar we have found 5/25 positive strains to PVL gene, in Heidelberg there was 1/49. PVL positive isolates were associated with spa-type t008 and agr-type I, thus, genetically, they were community-associated MRSA (CA-MRSA). Dipstick assay GenoType MRSA has demonstrated sufficient specificity, sensibility, simple performance and low cost, so we could introduce it to work in smaller laboratories. Using this method may expedite MRSA screening, thus preventing its spread in hospitals. PMID:26295294

  20. Antibacterial activity of extracellular compounds produced by a Pseudomonas strain against methicillin-resistant Staphylococcus aureus (MRSA) strains

    PubMed Central

    2013-01-01

    Background The emergence of multidrug-resistant bacteria is a world health problem. Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA) strains, is one of the most important human pathogens associated with hospital and community-acquired infections. The aim of this work was to evaluate the antibacterial activity of a Pseudomonas aeruginosa-derived compound against MRSA strains. Methods Thirty clinical MRSA strains were isolated, and three standard MRSA strains were evaluated. The extracellular compounds were purified by vacuum liquid chromatography. Evaluation of antibacterial activity was performed by agar diffusion technique, determination of the minimal inhibitory concentration, curve of growth and viability and scanning electron microscopy. Interaction of an extracellular compound with silver nanoparticle was studied to evaluate antibacterial effect. Results The F3 (ethyl acetate) and F3d (dichloromethane- ethyl acetate) fractions demonstrated antibacterial activity against the MRSA strains. Phenazine-1-carboxamide was identified and purified from the F3d fraction and demonstrated slight antibacterial activity against MRSA, and synergic effect when combined with silver nanoparticles produced by Fusarium oxysporum. Organohalogen compound was purified from this fraction showing high antibacterial effect. Using scanning electron microscopy, we show that the F3d fraction caused morphological changes to the cell wall of the MRSA strains. Conclusions These results suggest that P. aeruginosa-produced compounds such as phenazines have inhibitory effects against MRSA and may be a good alternative treatment to control infections caused by MRSA. PMID:23773484

  1. Staphylococcus aureus and Community-Associated Methicillin-Resistant Staphylococcus aureus (CA-MRSA) in and Around Therapeutic Whirlpools in College Athletic Training Rooms

    PubMed Central

    Kahanov, Leamor; Kim, Young Kyun; Eberman, Lindsey; Dannelly, Kathleen; Kaur, Haninder; Ramalinga, A.

    2015-01-01

    Context: Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has become a leading cause of skin and soft tissue infection in the nonhospitalized community. Care of the athletes in athletic training rooms is specifically designed with equipment tailored to the health care needs of the athletes, yet recent studies indicate that CA-MRSA is still prevalent in athletic facilities and that cleaning methods may not be optimal. Objective: To investigate the prevalence of Staphylococcus aureus and CA-MRSA in and around whirlpools in the athletic training room. Design: Cross-sectional study. Setting: National Collegiate Athletic Association Division I university. Patients or Other Participants: Student-athletes (n = 109) consisting of 46 men (42%) and 63 women (58%) representing 6 sports. Main Outcome Measure(s): Presence of MRSA and Staphylococcus aureus in and around the whirlpool structures relative to sport and number of athletes using the whirlpools. Results: We identified Staphylococcus aureus in 22% (n = 52/240) of the samples and MRSA in 0.8% (n = 2/240). A statistically significant difference existed between the number of athletes using the whirlpool and the presence of Staphylococcus aureus in and around the whirlpools (F2,238 = 2.445, P = .007). However, Staphylococcus aureus was identified regardless of whether multiple athletes used a whirlpool or no athletes used a whirlpool. We did not identify a relationship between the number of athletes who used a whirlpool and Staphylococcus aureus or MRSA density (P = .134). Conclusions: Staphylococcus aureus and MRSA were identified in and around the whirlpools. Transmission of the bacteria can be reduced by following the cleaning and disinfecting protocols recommended by the Centers for Disease Control and Prevention. Athletic trainers should use disinfectants registered by the Environmental Protection Agency to sanitize all whirlpools between uses. PMID:25710853

  2. Novel quorum-quenching agents promote methicillin-resistant Staphylococcus aureus (MRSA) wound healing and sensitize MRSA to β-lactam antibiotics.

    PubMed

    Kuo, David; Yu, Guanping; Hoch, Wyatt; Gabay, Dean; Long, Lisa; Ghannoum, Mahmoud; Nagy, Nancy; Harding, Clifford V; Viswanathan, Rajesh; Shoham, Menachem

    2015-03-01

    The dwindling repertoire of antibiotics to treat methicillin-resistant Staphylococcus aureus (MRSA) calls for novel treatment options. Quorum-quenching agents offer an alternative or an adjuvant to antibiotic therapy. Three biaryl hydroxyketone compounds discovered previously (F1, F12, and F19; G. Yu, D. Kuo, M. Shoham, and R. Viswanathan, ACS Comb Sci 16:85-91, 2014) were tested for efficacy in MRSA-infected animal models. Topical therapy of compounds F1 and F12 in a MRSA murine wound infection model promotes wound healing compared to the untreated control. Compounds F1, F12, and F19 afford significant survival benefits in a MRSA insect larva model. Combination therapy of these quorum-quenching agents with cephalothin or nafcillin, antibiotics to which MRSA is resistant in monotherapy, revealed additional survival benefits. The quorum-quenching agents sensitize MRSA to the antibiotic by a synergistic mode of action that also is observed in vitro. An adjuvant of 1 μg/ml F1, F12, or F19 reduces the MIC of nafcillin and cephalothin about 50-fold to values comparable to those for vancomycin, the antibiotic often prescribed for MRSA infections. These findings suggest that it is possible to resurrect obsolete antibiotic therapies in combination with these novel quorum-quenching agents.

  3. Novel Quorum-Quenching Agents Promote Methicillin-Resistant Staphylococcus aureus (MRSA) Wound Healing and Sensitize MRSA to β-Lactam Antibiotics

    PubMed Central

    Kuo, David; Yu, Guanping; Hoch, Wyatt; Gabay, Dean; Long, Lisa; Ghannoum, Mahmoud; Nagy, Nancy; Harding, Clifford V.; Viswanathan, Rajesh

    2014-01-01

    The dwindling repertoire of antibiotics to treat methicillin-resistant Staphylococcus aureus (MRSA) calls for novel treatment options. Quorum-quenching agents offer an alternative or an adjuvant to antibiotic therapy. Three biaryl hydroxyketone compounds discovered previously (F1, F12, and F19; G. Yu, D. Kuo, M. Shoham, and R. Viswanathan, ACS Comb Sci 16:85–91, 2014) were tested for efficacy in MRSA-infected animal models. Topical therapy of compounds F1 and F12 in a MRSA murine wound infection model promotes wound healing compared to the untreated control. Compounds F1, F12, and F19 afford significant survival benefits in a MRSA insect larva model. Combination therapy of these quorum-quenching agents with cephalothin or nafcillin, antibiotics to which MRSA is resistant in monotherapy, revealed additional survival benefits. The quorum-quenching agents sensitize MRSA to the antibiotic by a synergistic mode of action that also is observed in vitro. An adjuvant of 1 μg/ml F1, F12, or F19 reduces the MIC of nafcillin and cephalothin about 50-fold to values comparable to those for vancomycin, the antibiotic often prescribed for MRSA infections. These findings suggest that it is possible to resurrect obsolete antibiotic therapies in combination with these novel quorum-quenching agents. PMID:25534736

  4. Evaluation of the Xpert™ MRSA/SA Blood Culture assay for the detection of Staphylococcus aureus including strains with reduced vancomycin susceptibility from blood culture specimens.

    PubMed

    Kelley, Peter G; Grabsch, Elizabeth A; Farrell, Jenny; Xie, Shirley; Montgomery, Janet; Mayall, Barrie; Howden, Benjamin P

    2011-07-01

    The Xpert MRSA/SA Blood Culture (BC) assay (Cepheid, Sunnyvale, CA) was prospectively compared to culture and found to have excellent specificity for both Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) in BC specimens with a sensitivity of 75% (3/4) and 100% (17/17), respectively. Among 28 heterogeneous vancomycin-intermediate S. aureus (hVISA)/VISA spiked BCs, the assay correctly identified 84.6% VISA and 80% hVISA isolates as MRSA.

  5. Comparison of MRSASelect Agar, CHROMagar Methicillin-Resistant Staphylococcus aureus (MRSA) Medium, and Xpert MRSA PCR for Detection of MRSA in Nares: Diagnostic Accuracy for Surveillance Samples with Various Bacterial Densities ▿

    PubMed Central

    Wolk, D. M.; Marx, J. L.; Dominguez, L.; Driscoll, D.; Schifman, R. B.

    2009-01-01

    Rapid laboratory methods provide optimal support for active surveillance efforts to screen for methicillin-resistant Staphylococcus aureus (MRSA). Most laboratories struggle to determine the optimal use of resources, considering options to balance cost, speed, and diagnostic accuracy. To assess the performance of common methods, the first comparison of MRSASelect agar (MS) and CHROMagar MRSA (CA), with and without broth enrichment followed by a 24-h subculture to MS, was performed. Results were compared to those of the Xpert MRSA assay. For direct culture methods, the agreement between MS and CA was 98.8%. At 18 h, direct MS identified 93% of all positive samples from direct culture and 84% of those identified by the Xpert MRSA. For Trypticase soy broth-enriched MS culture, incubated overnight and then subcultured for an additional 24 h, the agreement with Xpert MRSA was 96%. The agreement between direct MS and Xpert MRSA was 100% when semiquantitative culture revealed a bacterial density of 2+ or greater; however, discrepancies between culture and Xpert MRSA arose for MRSA bacterial densities of 1+ or less, indicating low density as a common cause of false-negative culture results. Since 1+ or less was established as the most common MRSA carrier state, broth enrichment or PCR may be critical for the identification of all MRSA carriers who may be reservoirs for transmission. In this active-surveillance convenience sample, the use of broth enrichment followed by subculture to MS offered a low-cost but sensitive method for MRSA screening, with performance similar to that of Xpert MRSA PCR. PMID:19828738

  6. Discovery of bisindolyl-substituted cycloalkane-anellated indoles as novel class of antibacterial agents against S. aureus and MRSA.

    PubMed

    El-Sayed, Mardia Telep; Suzen, Sibel; Altanlar, Nurten; Ohlsen, Knut; Hilgeroth, Andreas

    2016-01-01

    Antibiotic resistance is an ongoing problem in the treatment of bacterial diseases. Among the various antibacterial infections Staphylococcus aureus infections remain critical due to the increasing resistances, especially against the methicillin-resistant S. aureus (MRSA). We discovered novel antibacterial compounds with activities against both S. aureus and MRSA types. Structure-activity relationships (SAR) are discussed and show that the activity depends on the ring size of the anellated cycloalkane. Moreover, first substituent effects have been investigated for both the cycloalkane and the indole residues.

  7. Solid lipid nanoparticles of clotrimazole silver complex: An efficient nano antibacterial against Staphylococcus aureus and MRSA.

    PubMed

    Kalhapure, Rahul S; Sonawane, Sandeep J; Sikwal, Dhiraj R; Jadhav, Mahantesh; Rambharose, Sanjeev; Mocktar, Chunderika; Govender, Thirumala

    2015-12-01

    New and effective strategies to transform current antimicrobials are required to address the increasing issue of microbial resistance and declining introduction of new antibiotic drugs. In this context, metal complexes of known drugs and nano delivery systems for antibiotics are proving to be promising strategies. The aim of the study was therefore to synthesize a silver complex of clotrimazole and formulate it into a nano delivery system for enhanced and sustained antibacterial activity against susceptible and resistant Staphylococcus aureus. A silver complex of clotrimazole was synthesized, characterized and further encapsulated into solid lipid nanoparticles to evaluate its antibacterial activity against S. aureus and methicillin-resistant S. aureus (MRSA). An in vitro cytotoxicity study was performed on HepG2 cell lines to assess the overall biosafety of the synthesized clotrimazole silver complex to mammalian cells, and was found to be non-toxic to mammalian cells (cell viability >80%). The minimum inhibitory concentrations (MIC) of clotrimazole and clotrimazole-silver were 31.25 and 9.76 μg/mL against S. aureus, and 31.25 and 15.62 against MRSA, respectively. Clotrimazole SLNs exhibited MIC values of 104 and 208 μg/mL against both MSSA and MRSA at the end of 18 and 36 h, respectively, but thereafter completely lost its antibacterial activity. Clotrimazole-silver SLNs had an MIC value of 52 μg/mL up to 54 h, after which the MIC value was 104 μg/mL against both strains at the end of 72 h. Thus, clotrimazole-silver SLNs was found to be an efficient nanoantibiotic.

  8. Solid lipid nanoparticles of clotrimazole silver complex: An efficient nano antibacterial against Staphylococcus aureus and MRSA.

    PubMed

    Kalhapure, Rahul S; Sonawane, Sandeep J; Sikwal, Dhiraj R; Jadhav, Mahantesh; Rambharose, Sanjeev; Mocktar, Chunderika; Govender, Thirumala

    2015-12-01

    New and effective strategies to transform current antimicrobials are required to address the increasing issue of microbial resistance and declining introduction of new antibiotic drugs. In this context, metal complexes of known drugs and nano delivery systems for antibiotics are proving to be promising strategies. The aim of the study was therefore to synthesize a silver complex of clotrimazole and formulate it into a nano delivery system for enhanced and sustained antibacterial activity against susceptible and resistant Staphylococcus aureus. A silver complex of clotrimazole was synthesized, characterized and further encapsulated into solid lipid nanoparticles to evaluate its antibacterial activity against S. aureus and methicillin-resistant S. aureus (MRSA). An in vitro cytotoxicity study was performed on HepG2 cell lines to assess the overall biosafety of the synthesized clotrimazole silver complex to mammalian cells, and was found to be non-toxic to mammalian cells (cell viability >80%). The minimum inhibitory concentrations (MIC) of clotrimazole and clotrimazole-silver were 31.25 and 9.76 μg/mL against S. aureus, and 31.25 and 15.62 against MRSA, respectively. Clotrimazole SLNs exhibited MIC values of 104 and 208 μg/mL against both MSSA and MRSA at the end of 18 and 36 h, respectively, but thereafter completely lost its antibacterial activity. Clotrimazole-silver SLNs had an MIC value of 52 μg/mL up to 54 h, after which the MIC value was 104 μg/mL against both strains at the end of 72 h. Thus, clotrimazole-silver SLNs was found to be an efficient nanoantibiotic. PMID:26492156

  9. The Pleiotropic Antibacterial Mechanisms of Ursolic Acid against Methicillin-Resistant Staphylococcus aureus (MRSA).

    PubMed

    Wang, Chao-Min; Jhan, Yun-Lian; Tsai, Shang-Jie; Chou, Chang-Hung

    2016-07-07

    (1) BACKGROUND: Several triterpenoids were found to act synergistically with classes of antibiotic, indicating that plant-derived chemicals have potential to be used as therapeutics to enhance the activity of antibiotics against multidrug-resistant pathogens. However, the mode of action of triterpenoids against bacterial pathogens remains unclear. The objective of this study is to evaluate the interaction between ursolic acid against methicillin-resistant Staphylococcus aureus (MRSA); (2) METHODS: The ability of ursolic acid to damage mammalian and bacterial membranes was examined. The proteomic response of methicillin-resistant S. aureus in ursolic acid treatment was investigated using two-dimensional (2D) proteomic analysis; (3) RESULTS: Ursolic acid caused the loss of staphylococcal membrane integrity without hemolytic activity. The comparison of the protein pattern of ursolic acid-treated and normal MRSA cells revealed that ursolic acid affected a variety of proteins involved in the translation process with translational accuracy, ribonuclease and chaperon subunits, glycolysis and oxidative responses; (4) CONCLUSION: The mode of action of ursolic acid appears to be the influence on the integrity of the bacterial membrane initially, followed by inhibition of protein synthesis and the metabolic pathway. These findings reflect that the pleiotropic effects of ursolic acid against MRSA make it a promising antibacterial agent in pharmaceutical research.

  10. The Pleiotropic Antibacterial Mechanisms of Ursolic Acid against Methicillin-Resistant Staphylococcus aureus (MRSA).

    PubMed

    Wang, Chao-Min; Jhan, Yun-Lian; Tsai, Shang-Jie; Chou, Chang-Hung

    2016-01-01

    (1) BACKGROUND: Several triterpenoids were found to act synergistically with classes of antibiotic, indicating that plant-derived chemicals have potential to be used as therapeutics to enhance the activity of antibiotics against multidrug-resistant pathogens. However, the mode of action of triterpenoids against bacterial pathogens remains unclear. The objective of this study is to evaluate the interaction between ursolic acid against methicillin-resistant Staphylococcus aureus (MRSA); (2) METHODS: The ability of ursolic acid to damage mammalian and bacterial membranes was examined. The proteomic response of methicillin-resistant S. aureus in ursolic acid treatment was investigated using two-dimensional (2D) proteomic analysis; (3) RESULTS: Ursolic acid caused the loss of staphylococcal membrane integrity without hemolytic activity. The comparison of the protein pattern of ursolic acid-treated and normal MRSA cells revealed that ursolic acid affected a variety of proteins involved in the translation process with translational accuracy, ribonuclease and chaperon subunits, glycolysis and oxidative responses; (4) CONCLUSION: The mode of action of ursolic acid appears to be the influence on the integrity of the bacterial membrane initially, followed by inhibition of protein synthesis and the metabolic pathway. These findings reflect that the pleiotropic effects of ursolic acid against MRSA make it a promising antibacterial agent in pharmaceutical research. PMID:27399657

  11. Descriptive Analysis of Antibiotic-Resistant Patterns of Methicillin-Resistant Staphylococcus aureus (MRSA) st398 Isolated from Healthy Swine

    PubMed Central

    Morcillo, Ana; Castro, Beatriz; Rodríguez-Álvarez, Cristobalina; Abreu, Rossana; Aguirre-Jaime, Armando; Arias, Angeles

    2015-01-01

    Background: Livestock-associated methicillin-resistant Staphylococcus aureus (MRSA) such as the MRSA ST398 strain has spread all over the World and the most worrying aspect of this fact appears to be its capacity to easily spread to humans. The excessive use of antibiotics has made swine a reservoir of MRSA. The aim of the present study was to determine the antibiotic resistance profile of MRSA samples isolated from healthy swine of the island of Tenerife (Spain). Methods: A total of 256 MRSA isolates from swine samples and five MRSA isolates from pig worker samples were investigated for MRSA antibiotic resistant patterns. Results: Analysis of the susceptibility status of MRSA pig isolates revealed that 39 isolates were resistant to one antibiotic, 71 isolates were resistant to two antibiotics and 96 isolates were resistant to three or more antibiotics. SCCmec typing revealed the presence of types IV and V. Isolates having SCCmec IV had an increased resistance to the antimicrobial agents tested than those having SCCmec V. We observed significant differences when comparing the most common resistance patterns and SCCmec type. Conclusions: MRSA isolated from humans showed similar resistance to those isolated from pigs, excepting erythromycin, since all the workers’ isolates were sensitive to this antibiotic. The evolution of new MRSA clones has emphasized the need for infection control practices in animals and humans in close contact. PMID:25588155

  12. [Methicillin resistance detection in Staphylococcus aureus: comparison between conventional methods and MRSA-Screen latex agglutination technique].

    PubMed

    Soloaga, R; Corso, A; Gagetti, P; Faccone, D; Galas, M

    2004-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a significant pathogen that has emerged over the last four decades, causing both nosocomial and community-acquired infections. Rapid and accurate detection of methicillin resistance in S. aureus is important for the use of appropriate antimicrobial therapy and for the control of nosocomial spread of MRSA strains. We evaluated the efficiency of conventional methods for detection of methicillin resistance such as the disk diffusion, agar dilution, oxacillin agar screen test, and the latex agglutination test MRSA-Screen latex, in 100 isolates of S. aureus, 79 mecA positive and 21 mecA negative. The MRSA-Screen latex (Denka Seiken, Niigata, Japón), is a latex agglutination method that detects the presence of PLP-2a, product of mecA gene in S. aureus. The PCR of the mecA gene was used as the "gold standard" for the evaluation of the different methods tested. The percentages of sensitivity and specificity were as follows: disk difusión 97 and 100%, agar dilution 97 and 95%, oxacillin agar screen test 100 and 100%, and MRSA-Screen latex, 100 and 100 %. All methods presented high sensitivity and specificity, but MRSA-Screen latex had the advantage of giving a reliable result, equivalent to PCR, in only 15 minutes.

  13. Dissemination of Methicillin-Resistant Staphylococcus aureus (MRSA), USA300 Sequence Type 8 Lineage in Latin-America

    PubMed Central

    Reyes, Jinnethe; Rincón, Sandra; Díaz, Lorena; Panesso, Diana; Contreras, Germán A.; Zurita, Jeannete; Carrillo, Carlos; Rizzi, Adele; Guzmán, Manuel; Adachi, Javier; Chowdhury, Shahreen; Murray, Barbara E.; Arias, Cesar A.

    2009-01-01

    Background Methicillin-resistant Staphylococus aureus (MRSA) is an important nosocomial and community-associated (CA) pathogen. Recently, a variant of the MRSA USA300 clone emerged and disseminated in South-America causing important clinical problems. Methods S. aureus isolates were prospectively collected (2006 to 2008) from 32 tertiary hospitals in Colombia, Ecuador, Peru, and Venezuela. MRSA isolates were subjected to antimicrobial susceptibility testing, pulsed field gel electrophoresis (PFGE), and categorized as healthcare-associated (HA)-like or CA-like clones based on genotypic characteristics and detection of genes encoding the Panton-Valentine leukocidin (PVL) and staphylococcal cassette mec (SCCmec) IV. Additionally, MLST of representative isolates of each major CA-MRSA pulsotype, and detection of USA300-associated toxins and the arcA gene were performed in all isolates categorized as CA-MRSA. Results A total of 1570 S. aureus were included; 651 were MRSA (41%), with the highest rates of MRSA isolation in Peru (62%), and lowest in Venezuela (26%) and 71%, 27%, and 2% were classified as HA-like, CA-like, and non-CA/HA-like clones, respectively. Only 9 MRSA isolates were confirmed to have reduced susceptibility to glycopeptides (GISA phenotype). The most common pulsotype (designated ComA) amongst the CA-like MRSA strains was found in 96% of isolates with the majority (81%) having ≤6 bands difference with the USA300-0114 strain. Representative isolates of this clone were ST8 but, unlike the USA300-0114 strain, they harbored a different SCCmec IV subtype and lacked arcA (an indicator of the arginine catabolic mobile element (ACME)). Conclusion A variant CA-MRSA USA300 clone has now become established in South America and, in some countries, is endemic in hospital settings. PMID:19911971

  14. In vitro activity of oritavancin against community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA), vancomycin-intermediate S. aureus (VISA), vancomycin-resistant S. aureus (VRSA) and daptomycin-non-susceptible S. aureus (DNSSA).

    PubMed

    Saravolatz, Louis D; Pawlak, Joan; Johnson, Leonard B

    2010-07-01

    Isolates of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA), vancomycin-intermediate S. aureus (VISA), vancomycin-resistant S. aureus (VRSA) and daptomycin non-susceptible S. aureus (DNSSA) are increasing in frequency and new antistaphylococcal therapies are needed. Microdilution testing using Mueller-Hinton broth was used to determine the minimal inhibitory concentrations (MICs) of oritavancin and nine additional antimicrobial agents against 92 CA-MRSA, 23 VISA, 7 DNSSA and 10 VRSA isolates. Minimal bactericidal concentrations were also determined. Pulsed-field gel electrophoresis (PFGE) was performed. Staphylococcal cassette chromosome mec (SCCmec) typing as well as assays for Panton-Valentine leukocidin (PVL) and arginine catabolic mobile element (ACME) genes were performed. Oritavancin was more bactericidal than any of the other comparators against CA-MRSA and demonstrated excellent activity against VRSA and VISA.

  15. Cardiac tamponade complicating purulent pericarditis due to community acquired methicilin resistant Staphylococcus aureus (CA-MRSA).

    PubMed

    Bagavathy, Kavitha; Raju, Shine K; Joseph, Ranjit; Kumar, Anupam

    2014-03-01

    Community acquired methicillin resistant Staphylococcus aureus(CA-MRSA) is a global pathogen capable of causing life-threatening infections with increasing prevalence since the 1990s. Purulentpericarditis, characterized by accumulation of purulent fluid in the pericardial space was historically a disease of the pediatric and early adult population, but through the years the median age of diagnosis has increased from 21 to 49. Mortality rates are as high as 40% even in the treated population. We report a case of purulent pericarditis due to CA-MRSA that was complicated by cardiac tamponade. Early diagnosis and intervention proved to be life-saving. A brief review of the literature and current management options are discussed.

  16. Detection of methicillin-resistant Staphylococcus aureus (MRSA) using the NanoLantern Biosensor

    NASA Astrophysics Data System (ADS)

    Strohsahl, Christopher M.; Miller, Benjamin L.; Krauss, Todd D.

    2009-02-01

    Staphylococcus aureus is a leading cause of human illness, and has developed the remarkable ability to resist the bactericidal capabilities of many of the world's leading antibiotics (i.e. MRSA). In an effort to enable rapid detection and treatment of MRSA infections, we have developed a DNA detection technology termed the NanoLantern(TM). The NanoLantern(TM) biosensor technology is based on the simple immobilization of a fluorophore-terminated DNA hairpin onto a gold chip. This produces a label-free sensor that allows for a positive response to be obtained without extensive processing of the sample, saving cost and increasing accuracy. We will also discuss a newly developed method of partial gene analysis, used to develop a DNA hairpin probe that is capable of detecting the presence of the mecR gene, a gene necessary for methicillin resistance to be present in S. aureus, with 100% sequence specificity. The successful incorporation of this probe into the NanoLantern(TM) platform, along with the concomitant development of the paired PCR assay has allowed for the successful detection of methicillin-resistance directly from a culture of S. aureus. These results represent an important step forward in terms of developing the ability to rapidly and effectively detect the presence of antibiotic resistance in bacterial infections.

  17. Identification and characterization of methicillin-resistant Staphylococcus aureus (MRSA) from Austrian companion animals and horses.

    PubMed

    Loncaric, Igor; Künzel, Frank; Licka, Theresia; Simhofer, Hubert; Spergser, Joachim; Rosengarten, Renate

    2014-01-31

    The aim of this study was to investigate the antimicrobial resistance, resistance gene patterns and genetic relatedness of a collection of Austrian methicillin-resistant Staphylococcus aureus (MRSA) isolates from companion animals and horses. A total of 89 non-repetitive MRSA isolates collected during routine veterinary microbiological examinations from April 2004 to the end of 2012, and one isolate from 2013 were used for this study. The presence of mecA and other resistance genes was confirmed by PCR. Isolates were genotyped by spa typing, two multiple-locus variable-number tandem repeat analyses (MLVA) analyses, SCCmec typing and multilocus sequence typing (MLST). PCR targeting Panton-Valentine leukocidin (PVL) and detection of staphylococcal enterotoxins (SE), toxic shock syndrome toxin (TSST) was performed using PCR assays. Antimicrobial susceptibility testing was performed. Five sequence types (STs-ST398, ST254, ST22, ST5 and ST1), SCCmec types II, IVa, V, and non-type-abele, 8 spa-types (t003, t011, t036, t127, t386, t1348, and t4450), and two isolates could not be assigned, 21 MLVA-14Orsay types Multiplex-PCR MLVA (mMLVA) displayed 17 different MLVA types. The present study is the most comprehensive dealing with MRSA from Austrian companion animals and horses. The results confirm that MRSA ST398 is present in a wide range of animal species and is predominant especially in horses. In other companion animals it is unclear whether the infections with the different MRSA isolates investigated in the present study truly represents a rare phenomenon or may be an emerging problem in companion animals.

  18. Vulvar Abscess Caused by Methicillin-resistant Staphylococcus Aureus (MRSA) in a Postmenopausal Woman

    PubMed Central

    Kim, Tae-Hee; Kim, Soo Ah; Heo, Gyeong-Eun

    2016-01-01

    Infections of the vulva can present a complex differential to the gynecologist, ranging from superficial skin infections to lifethreatening necrotizing fasciitis. Recognition and timely treatment remain universal to skin and soft-tissue infections as the subcutaneous anatomy of the vulva can facilitate rapid spread to other tissues with significant morbidity and mortality. Employing a multidisciplinary team approach to care for vulvar cellulitis and abscess can guide treatment from antibiotic therapies to more aggressive surgical debridement. In this report, we describe a case of vulvar abscess caused by Methicillin-resistant staphylococcus aureus (MRSA) in a postmenopausal woman with underlying diseases of bronchiectasis and atelectasis. PMID:27617247

  19. Vulvar Abscess Caused by Methicillin-resistant Staphylococcus Aureus (MRSA) in a Postmenopausal Woman

    PubMed Central

    Kim, Tae-Hee; Kim, Soo Ah; Heo, Gyeong-Eun

    2016-01-01

    Infections of the vulva can present a complex differential to the gynecologist, ranging from superficial skin infections to lifethreatening necrotizing fasciitis. Recognition and timely treatment remain universal to skin and soft-tissue infections as the subcutaneous anatomy of the vulva can facilitate rapid spread to other tissues with significant morbidity and mortality. Employing a multidisciplinary team approach to care for vulvar cellulitis and abscess can guide treatment from antibiotic therapies to more aggressive surgical debridement. In this report, we describe a case of vulvar abscess caused by Methicillin-resistant staphylococcus aureus (MRSA) in a postmenopausal woman with underlying diseases of bronchiectasis and atelectasis.

  20. Vulvar Abscess Caused by Methicillin-resistant Staphylococcus Aureus (MRSA) in a Postmenopausal Woman.

    PubMed

    Kim, Tae-Hee; Seap, Bel; Kim, Soo Ah; Heo, Gyeong-Eun

    2016-08-01

    Infections of the vulva can present a complex differential to the gynecologist, ranging from superficial skin infections to lifethreatening necrotizing fasciitis. Recognition and timely treatment remain universal to skin and soft-tissue infections as the subcutaneous anatomy of the vulva can facilitate rapid spread to other tissues with significant morbidity and mortality. Employing a multidisciplinary team approach to care for vulvar cellulitis and abscess can guide treatment from antibiotic therapies to more aggressive surgical debridement. In this report, we describe a case of vulvar abscess caused by Methicillin-resistant staphylococcus aureus (MRSA) in a postmenopausal woman with underlying diseases of bronchiectasis and atelectasis. PMID:27617247

  1. Extensive dissemination of methicillin-resistant Staphylococcus aureus (MRSA) between the hospital and the community in a country with a high prevalence of nosocomial MRSA.

    PubMed

    Espadinha, Diana; Faria, Nuno A; Miragaia, Maria; Lito, Luís Marques; Melo-Cristino, José; de Lencastre, Hermínia

    2013-01-01

    According to the EARS-Net surveillance data, Portugal has the highest prevalence of nosocomial methicillin-resistant Staphylococcus aureus (MRSA) in Europe, but the information on MRSA in the community is very scarce and the links between the hospital and community are not known. In this study we aimed to understand the events associated to the recent sharp increase in MRSA frequency in Portugal and to evaluate how this has shaped MRSA epidemiology in the community. With this purpose, 180 nosocomial MRSA isolates recovered from infection in two time periods and 14 MRSA isolates recovered from 89 samples of skin and soft tissue infections (SSTI) were analyzed by pulsed-field gel electrophoresis (PFGE), staphylococcal chromosome cassette mec (SCCmec) typing, spa typing and multilocus sequence typing (MLST). All isolates were also screened for the presence of Panton Valentine leukocidin (PVL) and arginine catabolic mobile element (ACME) by PCR. The results showed that ST22-IVh, accounting for 72% of the nosocomial isolates, was the major clone circulating in the hospital in 2010, having replaced two previous dominant clones in 1993, the Iberian (ST247-I) and Portuguese (ST239-III variant) clones. Moreover in 2010, three clones belonging to CC5 (ST105-II, ST125-IVc and ST5-IVc) accounted for 20% of the isolates and may represent the beginning of new waves of MRSA in this hospital. Interestingly, more than half of the MRSA isolates (8/14) causing SSTI in people attending healthcare centers in Portugal belonged to the most predominant clones found in the hospital, namely ST22-IVh (n = 4), ST5-IVc (n = 2) and ST105-II (n = 1). Other clones found included ST5-V (n = 6) and ST8-VI (n = 1). None of the MRSA isolates carried PVL and only five isolates (ST5-V-t179) carried ACME type II. The emergence and spread of EMRSA-15 may be associated to the observed increase in MRSA frequency in the hospital and the consequent spillover of MRSA into the community.

  2. Anti-methicillin-resistant Staphylococcus aureus (MRSA) activity of Rubiaceae, Fabaceae and Poaceae plants: A search for new sources of useful alternative antibacterials against MRSA infections.

    PubMed

    Sharifi-Rad, M; Iriti, M; Sharifi-Rad, M; Gibbons, S; Sharifi-Rad, J

    2016-01-01

    In this study, we evaluated the effects of the extracts of the leaves of species from the Rubiaceae (Galium aparine L. and Asperula arvensis L.), Fabaceae (Lathyrus aphaca L. and Vicia narbonensis L.) and Poaceae (Digitaria sanguinalis (L.) Scop. and Hordeum murinum L.) plant families on a wide and extensive panel of isolated methicillin-resistant Staphylococcus aureus strains (MRSA). The effects of the methanolic leaf extracts of Rubiaceae, Fabaceae and Poaceae plants on MRSA were evaluated by the disc diffusion assay and the broth dilution method. Among a total of 177 S. aureus isolates, 92 (51.97%) were found to be methicillin-resistant in an antibiogram and this was confirmed by the presence of the mecA gene in polymerase chain reaction method. All MRSA isolates were sensitive to all extracts. There were dose-dependent inhibitions on tested microorganisms for all plant extracts which showed maximum inhibition zones at a concentration of 300 mg/L. L. aphaca, G. aparine and H. murinum exhibited the highest antibacterial activity on the MRSA strains compared to the positive control (P < 0.05), as well as higher total polyphenol and flavonoid contents than other plant extracts. Minimum inhibitory concentrations on MRSA isolates ranged from 388.4 ± 0.2 mg/L, in D. sanguinalis, to 5.5 ± 0.1 mg/L, in L. aphaca. The methanolic extracts of L. aphaca (Fabaceae), G. aparine (Rubiaceae), and H. murinum (Poaceae) proved to have high antibacterial activity on MRSA isolates, thus representing promising antimicrobial agents in clinical settings. PMID:27585260

  3. Anti-methicillin-resistant Staphylococcus aureus (MRSA) activity of Rubiaceae, Fabaceae and Poaceae plants: A search for new sources of useful alternative antibacterials against MRSA infections.

    PubMed

    Sharifi-Rad, M; Iriti, M; Sharifi-Rad, M; Gibbons, S; Sharifi-Rad, J

    2016-01-01

    In this study, we evaluated the effects of the extracts of the leaves of species from the Rubiaceae (Galium aparine L. and Asperula arvensis L.), Fabaceae (Lathyrus aphaca L. and Vicia narbonensis L.) and Poaceae (Digitaria sanguinalis (L.) Scop. and Hordeum murinum L.) plant families on a wide and extensive panel of isolated methicillin-resistant Staphylococcus aureus strains (MRSA). The effects of the methanolic leaf extracts of Rubiaceae, Fabaceae and Poaceae plants on MRSA were evaluated by the disc diffusion assay and the broth dilution method. Among a total of 177 S. aureus isolates, 92 (51.97%) were found to be methicillin-resistant in an antibiogram and this was confirmed by the presence of the mecA gene in polymerase chain reaction method. All MRSA isolates were sensitive to all extracts. There were dose-dependent inhibitions on tested microorganisms for all plant extracts which showed maximum inhibition zones at a concentration of 300 mg/L. L. aphaca, G. aparine and H. murinum exhibited the highest antibacterial activity on the MRSA strains compared to the positive control (P < 0.05), as well as higher total polyphenol and flavonoid contents than other plant extracts. Minimum inhibitory concentrations on MRSA isolates ranged from 388.4 ± 0.2 mg/L, in D. sanguinalis, to 5.5 ± 0.1 mg/L, in L. aphaca. The methanolic extracts of L. aphaca (Fabaceae), G. aparine (Rubiaceae), and H. murinum (Poaceae) proved to have high antibacterial activity on MRSA isolates, thus representing promising antimicrobial agents in clinical settings.

  4. Structure elucidation of anti-methicillin resistant Staphylococcus aureus (MRSA) flavonoids from balsam poplar buds.

    PubMed

    Simard, François; Gauthier, Charles; Legault, Jean; Lavoie, Serge; Mshvildadze, Vakhtang; Pichette, André

    2016-09-15

    There is nowadays an urgent need for developing novel generations of antibiotic agents due to the increased resistance of pathogenic bacteria. As a rich reservoir of structurally diverse compounds, plant species hold promise in this regard. Within this framework, we isolated a unique series of antibacterial flavonoids, named balsacones N-U, featuring multiple cinnamyl chains on the flavan skeleton. The structures of these compounds, isolated as racemates, were determined using extensive 1D and 2D NMR analysis in tandem with HRMS. Balsacones N-U along with previously isolated balsacones A-M were evaluated for their antibacterial activity against clinical isolates of methicillin resistant Staphylococcus aureus (MRSA). Several of the tested balsacones were potent anti-MRSA agents showing MIC values in the low micromolar range. Structure-activity relationships study highlighted some important parameters involved in the antibacterial activity of balsacones such as the presence of cinnamyl and cinnamoyl chains at the C-3 and C-8 positions of the flavan skeleton, respectively. These results suggest that balsacones could represent a potential novel class of naturally occurring anti-MRSA agents.

  5. Control of spread of Methicillin Resistant Staphylococcus aureus (MRSA) in Burns Units.

    PubMed

    Muthotho, James N.; Waiyaki, Peter G.; Mbalu, Michael; Wairugu, Anne; Mwanthi, Beth; Odongo, Ben

    1995-02-01

    Results of four years' studies from a number of hospitals in Kenya have shown that nosocomial infections in burns units are due to Methicillin Resistant Staphylococcus aureus (MRSA). Through chromosomal DNA and plasmid DNA, the stain is highly resistant to sulphonamide ointment and other antibiotics. 90% of patients admitted in burns units get colonized or infected with MRSA. The strain prolongs the duration of patients in hospitals. The burns degenerate to second and third degree burns, thereby necessitating skin grafting. The environment has been found to be contaminated with this strain with some staff members having chronic throat infections. Minocycline was found to be effective in treating the infected staff members. Cleaning this environment with Sodium dichloroisocyanurate (precepts)/Sodium hypochlorite (JIK) reduced drastically the mechanical transmission of bacteria in the units. The duration of stay of the patient was reduced. This shows that MRSA which is spread in government and private hospitals can cheaply be controlled by the proper use of disinfectants, antiseptics, and use of effective antibiotics when necessary. PMID:12160450

  6. Structure elucidation of anti-methicillin resistant Staphylococcus aureus (MRSA) flavonoids from balsam poplar buds.

    PubMed

    Simard, François; Gauthier, Charles; Legault, Jean; Lavoie, Serge; Mshvildadze, Vakhtang; Pichette, André

    2016-09-15

    There is nowadays an urgent need for developing novel generations of antibiotic agents due to the increased resistance of pathogenic bacteria. As a rich reservoir of structurally diverse compounds, plant species hold promise in this regard. Within this framework, we isolated a unique series of antibacterial flavonoids, named balsacones N-U, featuring multiple cinnamyl chains on the flavan skeleton. The structures of these compounds, isolated as racemates, were determined using extensive 1D and 2D NMR analysis in tandem with HRMS. Balsacones N-U along with previously isolated balsacones A-M were evaluated for their antibacterial activity against clinical isolates of methicillin resistant Staphylococcus aureus (MRSA). Several of the tested balsacones were potent anti-MRSA agents showing MIC values in the low micromolar range. Structure-activity relationships study highlighted some important parameters involved in the antibacterial activity of balsacones such as the presence of cinnamyl and cinnamoyl chains at the C-3 and C-8 positions of the flavan skeleton, respectively. These results suggest that balsacones could represent a potential novel class of naturally occurring anti-MRSA agents. PMID:27436809

  7. Knowing prior methicillin-resistant Staphylococcus aureus (MRSA) infection or colonization status increases the empirical use of glycopeptides in MRSA bacteraemia and may decrease mortality.

    PubMed

    Robinson, J O; Phillips, M; Christiansen, K J; Pearson, J C; Coombs, G W; Murray, R J

    2014-06-01

    To compare the management and outcome of methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia in patients known to be MRSA-colonized/infected (C-patients) with the management and outcome in those not known to be colonized/infected (NC-patients), we conducted a 10-year retrospective review of MRSA bacteraemia in an adult tertiary hospital. Clinical data were obtained by chart review, and mortality data from linked databases. Prior MRSA colonization/infection status was available to treating clinicians at the time of the bacteraemia as a 'Micro-Alert' tag on the patient's labels, in medical charts, and in electronic information systems. C-patients accounted for 35.4% of all MRSA bacteraemia episodes. C-patients were more likely to be indigenous, to be diabetic, or to have a history of previous S. aureus infection. Markers of illness severity (Simplified Acute Physiology Score (SAPS)-II, need for admission to the intensive-care unit, length of stay, and metastatic seeding) were similar in both groups. Empirical therapy included a glycopeptide in 49.3% of C-patients vs. 18.9% of NC-patients (p <0.01), and contained an antibiotic to which the MRSA isolate tested susceptible in vitro in 56.7% of C-patients vs. 45.1% of NC-patients (p 0.13). All-cause 7-day and 30-day mortality were 7.5% vs. 18.9% (p 0.04), and 22.4% vs. 31.1% (p 0.20), in the C-patient and NC-patient groups, respectively. Knowing MRSA colonization status was significantly associated with lower 30-day mortality in Cox regression analysis (p <0.01). These data suggest that mortality from MRSA bacteraemia is lower in C-patients, which may reflect the earlier use of glycopeptides. The low use of empirical glycopeptides in septic patients known to be previously MRSA-colonized/infected may represent a missed opportunity for infection control to positively impact on clinical management.

  8. Knowing prior methicillin-resistant Staphylococcus aureus (MRSA) infection or colonization status increases the empirical use of glycopeptides in MRSA bacteraemia and may decrease mortality.

    PubMed

    Robinson, J O; Phillips, M; Christiansen, K J; Pearson, J C; Coombs, G W; Murray, R J

    2014-06-01

    To compare the management and outcome of methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia in patients known to be MRSA-colonized/infected (C-patients) with the management and outcome in those not known to be colonized/infected (NC-patients), we conducted a 10-year retrospective review of MRSA bacteraemia in an adult tertiary hospital. Clinical data were obtained by chart review, and mortality data from linked databases. Prior MRSA colonization/infection status was available to treating clinicians at the time of the bacteraemia as a 'Micro-Alert' tag on the patient's labels, in medical charts, and in electronic information systems. C-patients accounted for 35.4% of all MRSA bacteraemia episodes. C-patients were more likely to be indigenous, to be diabetic, or to have a history of previous S. aureus infection. Markers of illness severity (Simplified Acute Physiology Score (SAPS)-II, need for admission to the intensive-care unit, length of stay, and metastatic seeding) were similar in both groups. Empirical therapy included a glycopeptide in 49.3% of C-patients vs. 18.9% of NC-patients (p <0.01), and contained an antibiotic to which the MRSA isolate tested susceptible in vitro in 56.7% of C-patients vs. 45.1% of NC-patients (p 0.13). All-cause 7-day and 30-day mortality were 7.5% vs. 18.9% (p 0.04), and 22.4% vs. 31.1% (p 0.20), in the C-patient and NC-patient groups, respectively. Knowing MRSA colonization status was significantly associated with lower 30-day mortality in Cox regression analysis (p <0.01). These data suggest that mortality from MRSA bacteraemia is lower in C-patients, which may reflect the earlier use of glycopeptides. The low use of empirical glycopeptides in septic patients known to be previously MRSA-colonized/infected may represent a missed opportunity for infection control to positively impact on clinical management. PMID:24224545

  9. Characterization of PVL/ACME-positive methicillin-resistant Staphylococcus aureus (genotypes ST8-MRSA-IV and ST5-MRSA-II) isolated from a university hospital in Japan.

    PubMed

    Kawaguchiya, Mitsuyo; Urushibara, Noriko; Yamamoto, Dai; Yamashita, Toshiharu; Shinagawa, Masaaki; Watanabe, Naoki; Kobayashi, Nobumichi

    2013-02-01

    The ST8 methicillin-resistant Staphylococcus aureus (MRSA) with Staphylococcal cassette chromosome mec (SCCmec) type IVa, known as USA300, is a prevalent community-acquired MRSA (CA-MRSA) clone in the United States and has been spreading worldwide. The USA300 characteristically harbors Panton-Valentine Leukocidin (PVL) genes and the arginine catabolic mobile element (ACME, type I). Prevalence and molecular characteristics of PVL(+) and/or ACME(+) S. aureus were investigated in a university hospital located in northern Japan, for 1,366 S. aureus isolates, including 601 MRSA strains derived from clinical specimens collected from 2008 to 2010. The PVL gene was identified in three MRSA strains with SCCmec IV, which belonged to ST8, spa type t008, coagulase type III, and agr type I. Two PVL-positive MRSA strains had also type I ACME, and were isolated from skin abscess of outpatients who have not travelled abroad recently. One of these PVL(+)/ACME(+) strains carried tet(K), msrA, and aph(3')-IIIa, showing resistance to kanamycin, tetracycline, erythromycin, and ciprofloxacin, suggesting acquisition of more resistance than ST8 CA-MRSA reported in Japan previously. In contrast, another PVL(+)/ACME(+) strain and a PVL(+)/ACME(-) strain were susceptible to more antimicrobials and had less virulence factors than PVL(-)/ACME(+) MRSA strains. Besides the two PVL(+) MRSA strains, ACME (type-ΔII) was identified into seven MRSA strains with SCCmec II belonging to ST5, one of the three spa types (t002, t067, and t071), coagulase type II, and agr type II. These PVL(-)/ACME(+) MRSA strains showed multiple drug resistance and harbored various toxin genes as observed for ST5 PVL(-)/ACME(-) MRSA-II. The present study suggested the spread of ST8-MRSA-IV in northern Japan, and a potential significance of ACME-positive ST5-MRSA-II as an emerging MRSA clone in a hospital.

  10. Rapid confirmation of suspected methicillin-resistant Staphylococcus aureus colonies on chromogenic agars by a new commercial PCR assay, the GenomEra MRSA/SA Diagnose.

    PubMed

    Hirvonen, J J; Nevalainen, M; Tissari, P; Salmenlinna, S; Rantakokko-Jalava, K; Kaukoranta, S-S

    2012-08-01

    A new automated closed tube PCR assay, the GenomEra(™) MRSA/SA Diagnose (Abacus Diagnostica Oy, Finland) was evaluated for rapid confirmation of methicillin-resistant Staphylococcus aureus (MRSA) from cultured screening specimens. The ability of the assay to detect genotypically different MRSA strains was studied with a collection of 304 MRSA isolates covering 68 spa types. The specificity was investigated with a collection of 146 non-MRSA staphylococcus isolates. The usefulness of the assay for clinical purposes was assessed by a sequential combination of MRSA screening culture and confirmation of the colonies with the GenomEra MRSA/SA Diagnose assay. A total of 145 suspected MRSA colonies on chromogenic plates were analyzed this way. All MRSA isolates from the culture collection and from the clinical screening specimens were confirmed as MRSA with the GenomEra MRSA/SA Diagnose assay and none of the non-MRSA staphylococci caused false-positive results, which indicates both sensitivity and specificity of 100%. The combination of GenomEra MRSA/SA Diagnose with preceding culture on selective MRSA agar permitted MRSA confirmation within 24 h. This practice offers a reliable and quick detection of MRSA that is also suitable in areas where several strain types cause epidemics.

  11. Genotypic and phenotypic characterization of methicillin-resistant Staphylococcus aureus (MRSA) clones with high-level mupirocin resistance.

    PubMed

    González-Domínguez, María; Seral, Cristina; Potel, Carmen; Sáenz, Yolanda; Álvarez, Maximiliano; Torres, Carmen; Castillo, Francisco Javier

    2016-06-01

    A high proportion of methicillin-resistant Staphylococcus aureus isolates recovered in one year period showed high-level mupirocin-resistance (HLMUPR-MRSA) in our environment (27.2%). HLMUPR-MRSA isolates were mainly collected from skin and soft tissue samples, and diabetes was the main related comorbidity condition. These isolates were more frequently found in vascular surgery. HLMUPR-MRSA was more resistant to aminoglycosides than mupirocin-susceptible MRSA, linked to the presence of bifunctional and/or nucleotidyltransferase enzymes with/without macrolide resistance associated with the msr(A) gene. Most of HLMUPR-MRSA isolates belonged to ST125/t067. Nine IS257-ileS2 amplification patterns (p3 was the most frequent) were observed in HLMUPR-MRSA isolates, suggesting the presence of several mupirocin-resistance-carrying plasmids in our environment and promoting the emergence of mupirocin resistance. The presence of the same IS257-ileS2 amplification pattern p3 in 65% of HLMUPR-MRSA, all of them ST125/t067, suggests a clonal spread in our hospital and community environment which could explain the high prevalence of HLMUPR-MRSA during the study period. An outbreak situation or an increase in mupirocin consumption was not observed.

  12. [State of infection caused by methicillin-resistant Staphylococcus aureus (MRSA) in Extremadura: susceptibility, clonality and role of community-associated MRSA].

    PubMed

    Aguadero, V; González-Velasco, C; Vindel, A; González-Velasco, M; Moreno, J J

    2014-09-01

    The correct surveillance and control of infection caused by methicillin-resistant Staphylococcus aureus (MRSA) needs of update knowledge of its specific properties in each place. Our study aims to describe the current characteristics of infection due to MRSA in Extremadura. During 2010, 309 MRSA were collected from clinical samples in our region. A susceptibility test that included 17 antibiotics tested by AST -588 card Vitek 2 ® and E -test method was performed on all isolates. A sample of 100 strains, selected by stratified random sampling, were genotyped by pulsed field electrophoresis (PFGE). The prevalence of MRSA in Extremadura was 20.2%. Don Benito-Villanueva area showed the most prevalence and a higher incidence. Merida reported the most favourable situation, with a relatively low ratios of prevalence and incidence. The community acquired reached 44 % in the region, showing predominantly in less populated areas (Navalmoral and Coria). The most common multiresistant pattern was tobramycin-levofloxacin-erythromycin (44%), followed tobramycin-erythromycin-clindamycin (20%). No linezolid, daptomycin and tigecycline resistant strains were observed, but 42 % of the MRSA strains showed decreased susceptibility vancomycin (DSV). PFGE analysis reported 27 genotypes, with 3 major genotypes: E8a (25%), E7b (17%) and E7a (12%). The post-hoc statistical analysis did not reveal significant differences in the distribution of genotypes between different areas. However it revealed some trends that should be considered.

  13. Rifampicin and sodium fusidate reduces the frequency of methicillin-resistant Staphylococcus aureus (MRSA) isolation in adults with cystic fibrosis and chronic MRSA infection.

    PubMed

    Garske, L A; Kidd, T J; Gan, R; Bunting, J P; Franks, C A; Coulter, C; Masel, P J; Bell, S C

    2004-03-01

    Nosocomial transmission of methicillin-resistant Staphylococcus aureus (MRSA) to patients with cystic fibrosis (CF) frequently results in chronic respiratory tract carriage. This is an increasing problem, adds to the burden of glycopeptide antibiotic use in hospitals, and represents a relative contraindication to lung transplantation. The aim of this study was to determine whether it is possible to eradicate MRSA with prolonged oral combination antibiotics, and whether this treatment is associated with improved clinical status. Adult CF patients (six male, one female) with chronic MRSA infection were treated for six months with rifampicin and sodium fusidate. Outcome data were examined for six months before treatment, on treatment and after treatment. The patients had a mean age of 29.3 (standard deviation=6.3) years and FEV(1) of 36.1% (standard deviation=12.7) predicted. The mean duration of MRSA isolation was 31 months. MRSA isolates identified in these patients was of the same lineage as the known endemic strain at the hospital when assessed by pulsed-field gel electrophoresis. Five of the seven had no evidence of MRSA during and for at least six months after rifampicin and sodium fusidate. The proportion of sputum samples positive for MRSA was lower during the six months of treatment (0.13) and after treatment (0.19) compared with before treatment (0.85) (P<0.0001). There was a reduction in the number of days of intravenous antibiotics per six months with 20.3+/-17.6 on treatment compared with 50.7 before treatment and 33.0 after treatment (P=0.02). There was no change in lung function. Gastrointestinal side effects occurred in three, but led to therapy cessation in only one patient. Despite the use of antibiotics with anti-staphylococcal activity for treatment of respiratory exacerbation, MRSA infection persists. MRSA can be eradicated from the sputum of patients with CF and chronic MRSA carriage by using rifampicin and sodium fusidate for six months. This

  14. Isolation, Virulence, and Antimicrobial Resistance of Methicillin-Resistant Staphylococcus aureus (MRSA) and Methicillin Sensitive Staphylococcus aureus (MSSA) Strains from Oklahoma Retail Poultry Meats

    PubMed Central

    Abdalrahman, Lubna S.; Stanley, Adriana; Wells, Harrington; Fakhr, Mohamed K.

    2015-01-01

    Staphylococcus aureus is one the top five pathogens causing domestically acquired foodborne illness in the U.S. Only a few studies are available related to the prevalence of S. aureus and MRSA in the U.S. retail poultry industry. The objectives of this study were to determine the prevalence of S. aureus (MSSA and MRSA) in retail chicken and turkey meats sold in Tulsa, Oklahoma and to characterize the recovered strains for their antimicrobial resistance and possession of toxin genes. A total of 167 (114 chicken and 53 turkey) retail poultry samples were used in this study. The chicken samples included 61 organic samples while the rest of the poultry samples were conventional. The overall prevalence of S. aureus was 57/106 (53.8%) in the conventional poultry samples and 25/61 (41%) in the organic ones. Prevalence in the turkey samples (64.2%) was higher than in the chicken ones (42.1%). Prevalence of S. aureus did not vary much between conventional (43.4%) and organic chicken samples (41%). Two chicken samples 2/114 (1.8%) were positive for MRSA. PFGE identified the two MRSA isolates as belonging to PFGE type USA300 (from conventional chicken) and USA 500 (from organic chicken) which are community acquired CA-MRSA suggesting a human based source of contamination. MLST and spa typing also supported this conclusion. A total of 168 Staphylococcus aureus isolates (101 chicken isolates and 67 turkey isolates) were screened for their antimicrobial susceptibility against 16 antimicrobials and their possession of 18 different toxin genes. Multidrug resistance was higher in the turkey isolates compared to the chicken ones and the percentage of resistance to most of the antimicrobials tested was also higher among the turkey isolates. The hemolysin hla and hld genes, enterotoxins seg and sei, and leucocidins lukE-lukD were more prevalent in the chicken isolates. The PVL gene lukS-lukF was detected only in chicken isolates including the MRSA ones. In conclusion, S. aureus is

  15. Isolation, Virulence, and Antimicrobial Resistance of Methicillin-Resistant Staphylococcus aureus (MRSA) and Methicillin Sensitive Staphylococcus aureus (MSSA) Strains from Oklahoma Retail Poultry Meats.

    PubMed

    Abdalrahman, Lubna S; Stanley, Adriana; Wells, Harrington; Fakhr, Mohamed K

    2015-05-29

    Staphylococcus aureus is one the top five pathogens causing domestically acquired foodborne illness in the U.S. Only a few studies are available related to the prevalence of S. aureus and MRSA in the U.S. retail poultry industry. The objectives of this study were to determine the prevalence of S. aureus (MSSA and MRSA) in retail chicken and turkey meats sold in Tulsa, Oklahoma and to characterize the recovered strains for their antimicrobial resistance and possession of toxin genes. A total of 167 (114 chicken and 53 turkey) retail poultry samples were used in this study. The chicken samples included 61 organic samples while the rest of the poultry samples were conventional. The overall prevalence of S. aureus was 57/106 (53.8%) in the conventional poultry samples and 25/61 (41%) in the organic ones. Prevalence in the turkey samples (64.2%) was higher than in the chicken ones (42.1%). Prevalence of S. aureus did not vary much between conventional (43.4%) and organic chicken samples (41%). Two chicken samples 2/114 (1.8%) were positive for MRSA. PFGE identified the two MRSA isolates as belonging to PFGE type USA300 (from conventional chicken) and USA 500 (from organic chicken) which are community acquired CA-MRSA suggesting a human based source of contamination. MLST and spa typing also supported this conclusion. A total of 168 Staphylococcus aureus isolates (101 chicken isolates and 67 turkey isolates) were screened for their antimicrobial susceptibility against 16 antimicrobials and their possession of 18 different toxin genes. Multidrug resistance was higher in the turkey isolates compared to the chicken ones and the percentage of resistance to most of the antimicrobials tested was also higher among the turkey isolates. The hemolysin hla and hld genes, enterotoxins seg and sei, and leucocidins lukE-lukD were more prevalent in the chicken isolates. The PVL gene lukS-lukF was detected only in chicken isolates including the MRSA ones. In conclusion, S. aureus is

  16. Salicylanilide carbamates: Promising antibacterial agents with high in vitro activity against methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Zadrazilova, Iveta; Pospisilova, Sarka; Masarikova, Martina; Imramovsky, Ales; Ferriz, Juana Monreal; Vinsova, Jarmila; Cizek, Alois; Jampilek, Josef

    2015-09-18

    A series of twenty-one salicylanilide N-alkylcarbamates was assessed for novel antibacterial characteristics against three clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and S. aureus ATCC 29213 as the reference and quality control strain. The minimum inhibitory concentration was determined by the broth dilution micro-method with subsequent subcultivation of aliquots to assess minimum bactericidal concentration. The bactericidal kinetics was established by time-kill assay. Ampicillin, ciprofloxacin and vancomycin were used as reference antibacterial drugs. All the tested compounds exhibited highly potent anti-MRSA activity (⩽ 0.008-4 μg/mL) comparable or up to 250× higher than that of vancomycin, the standard in the treatment of serious MRSA infections. 4-Chloro-2-(3,4-dichlorophenylcarbamoyl)phenyl butylcarbamate and 4-chloro-2-(3,4-dichlorophenylcarbamoyl)phenyl ethylcarbamate were the most active compounds. In most cases, compounds provided reliable bacteriostatic activity, except for 4-chloro-2-(4-chlorophenylcarbamoyl)phenyl decylcarbamate exhibiting bactericidal effect at 8h (for clinical isolate of MRSA 63718) and at 24h (for clinical isolates of MRSA SA 630 and MRSA SA 3202) at 4× MIC. Structure-activity relationships are discussed.

  17. Comparison of the Xpert methicillin-resistant Staphylococcus aureus (MRSA) assay, BD GeneOhm MRSA assay, and culture for detection of nasal and cutaneous groin colonization by MRSA.

    PubMed

    Kelley, P G; Grabsch, E A; Howden, B P; Gao, W; Grayson, M L

    2009-11-01

    Detection of methicillin (meticillin)-resistant Staphylococcus aureus colonization was assessed using combined nose and groin swabs in two commercial PCR assays (the Xpert MRSA assay and the BD GeneOhm MRSA assay). Compared to routine culture, both had similar sensitivities (87.0% versus 84.8%, respectively) and specificities (93.8% versus 92.7%, respectively). Combined PCR assays provide a rapid and more-complete assessment of colonization at a cost similar to that of single-site analysis.

  18. Noninvasive in vivo imaging to evaluate immune responses and antimicrobial therapy against Staphylococcus aureus and USA300 MRSA skin infections.

    PubMed

    Cho, John S; Zussman, Jamie; Donegan, Niles P; Ramos, Romela Irene; Garcia, Nairy C; Uslan, Daniel Z; Iwakura, Yoichiro; Simon, Scott I; Cheung, Ambrose L; Modlin, Robert L; Kim, Jenny; Miller, Lloyd S

    2011-04-01

    Staphylococcus aureus skin infections represent a significant public health threat because of the emergence of antibiotic-resistant strains such as methicillin-resistant S. aureus (MRSA). As greater understanding of protective immune responses and more effective antimicrobial therapies are needed, a S. aureus skin wound infection model was developed in which full-thickness scalpel cuts on the backs of mice were infected with a bioluminescent S. aureus (methicillin sensitive) or USA300 community-acquired MRSA strain and in vivo imaging was used to noninvasively monitor the bacterial burden. In addition, the infection-induced inflammatory response was quantified using in vivo fluorescence imaging of LysEGFP mice. Using this model, we found that both IL-1α and IL-1β contributed to host defense during a wound infection, whereas IL-1β was more critical during an intradermal S. aureus infection. Furthermore, treatment of a USA300 MRSA skin infection with retapamulin ointment resulted in up to 85-fold reduction in bacterial burden and a 53% decrease in infection-induced inflammation. In contrast, mupirocin ointment had minimal clinical activity against this USA300 strain, resulting in only a 2-fold reduction in bacterial burden. Taken together, this S. aureus wound infection model provides a valuable preclinical screening method to investigate cutaneous immune responses and the efficacy of topical antimicrobial therapies.

  19. Linezolid minimum inhibitory concentration (MIC) creep in methicillin-resistant Staphylococcus aureus (MRSA) clinical isolates at a single Japanese center.

    PubMed

    Miyazaki, Motoyasu; Nagata, Nobuhiko; Miyazaki, Hiroyuki; Matsuo, Koichi; Takata, Tohru; Tanihara, Shinichi; Kamimura, Hidetoshi

    2014-01-01

    The aim of this study was to evaluate whether linezolid minimum inhibitory concentration (MIC) creep occurred in Staphylococcus aureus clinical isolates, including methicillin-resistant S. aureus (MRSA), over a recent 5-year period at a single Japanese center. A total of 453 MRSA and 195 methicillin-susceptible S. aureus (MSSA) isolates recovered from inpatients from April 1, 2008 to March 31, 2013 were analyzed. The MIC of linezolid was determined by automated Vitek-2 system. The modal MIC, MIC range, MIC50 and MIC90 (MICs required to inhibit the growth of 50% and 90% of organisms, respectively), geometric mean MIC and percentages of susceptible and resistant isolates were evaluated for each fiscal year. None of the S. aureus isolates were resistant to linezolid. Isolates with an MIC of >1 µg/mL were more common in the MSSA samples than in the MRSA samples (91.3% versus 38.2%, p<0.001). The linezolid geometric mean MIC increased by 0.403 µg/mL (from 1.178 in 2008 to 1.582 in 2012) in the MRSA isolates (p=0.006, r(2)=0.945 according to a linear regression analysis) over the 5-year period; however, no increase was observed in the MSSA isolates. The frequency of MRSA isolates with an MIC of 1 µg/mL decreased (from 76.3% in 2008 to 35.4% in 2012) and the isolates with MICs of >1 µg/mL increased over time (from 23.7% in 2008 to 64.6% in 2012). This report demonstrates the occurrence of linezolid MIC creep, as determined using the geometric mean MIC, in MRSA clinical isolates at a single Japanese center.

  20. Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) isolates of swine origin form robust biofilms.

    PubMed

    Nicholson, Tracy L; Shore, Sarah M; Smith, Tara C; Frana, Timothy S; Fraena, Timothy S

    2013-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) colonization of livestock animals is common and prevalence rates for pigs have been reported to be as high as 49%. Mechanisms contributing to the persistent carriage and high prevalence rates of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) strains in swine herds and production facilities have not been investigated. One explanation for the high prevalence of MRSA in swine herds is the ability of these organisms to exist as biofilms. In this report, the ability of swine LA-MRSA strains, including ST398, ST9, and ST5, to form biofilms was quantified and compared to several swine and human isolates. The contribution of known biofilm matrix components, polysaccharides, proteins and extracellular DNA (eDNA), was tested in all strains as well. All MRSA swine isolates formed robust biofilms similar to human clinical isolates. The addition of Dispersin B had no inhibitory effect on swine MRSA isolates when added at the initiation of biofilm growth or after pre-established mature biofilms formed. In contrast, the addition of proteinase K inhibited biofilm formation in all strains when added at the initiation of biofilm growth and was able to disperse pre-established mature biofilms. Of the LA-MRSA strains tested, we found ST398 strains to be the most sensitive to both inhibition of biofilm formation and dispersal of pre-formed biofilms by DNaseI. Collectively, these findings provide a critical first step in designing strategies to control or eliminate MRSA in swine herds.

  1. [Molecular epidemiological study of community-acquired methicillin-resistant staphylococcus aureus (CA-MRSA) - an examination of commercially distributed meat as a possible vehicle for CA-MRSA].

    PubMed

    Ogata, Kikuyo; Narimatsu, Hiroshi; Suzuki, Masahiro; Higuchi, Wataru; Yamamoto, Tatsuo; Taniguchi, Hatsumi

    2014-09-01

    Staphylococcus aureus has occupied an important position in public health as a cause of food poisoning and hospital-acquired MRSA (HA-MRSA) infections. The spread of community-acquired MRSA (CA-MRSA) infections has also recently become a concern. However, the sources of this infection remain unclear, and there are few reports of epidemiology information. In order to understand MRSA spread in the community, we investigated the distribution of MRSA strains in commercially distributed raw meat samples (n=305) and stool samples from outpatients with diarrhea (n=1,543) from the same meat distribution region in Oita Prefecture, Japan. 301 Staphylococcus aureus strains were isolated and 18 of them were MRSA (2 from chicken meat, 1 from duck meat, 1 from pork meat, and 14 from patients with diarrhea). All 18 MRSA strains were negative for Panton-Valentine leucocidin gene. In this study conducting a comparison of properties and a molecular epidemiological analysis of MRSA isolated from commercially distributed meat and diarrhea patient stools, the results suggest that commercially distributed meat could play a role in the prevalence of CA-MRSA in the community.

  2. Anti-Glucosaminidase Monoclonal Antibodies as a Passive Immunization for Methicillin-Resistant Staphylococcus aureus (MRSA) Orthopaedic Infections.

    PubMed

    Varrone, John J; Li, Dan; Daiss, John L; Schwarz, Edward M

    2011-04-01

    Recently, methicillin-resistant Staphylococcus aureus (MRSA) has surpassed HIV as the most deadly pathogen in the United States, accounting for over 100,000 deaths per year. In orthopedics, MRSA osteomyelitis has become the greatest concern in patient care, despite the fact that improvements in surgical technique and aggressive antibiotic prophylaxis have decreased the infection rate for most procedures to less than 5%. This great concern is largely due to the very poor outcomes associated with MRSA osteomyelitis, which includes 30-50% failure rates for revision surgery. Thus, there is a need to develop additional therapeutic interventions such as passive immunization, particularly for immunocompromised patients and the elderly who are typically poor responders to active vaccines. Using a novel murine model of implant-associated osteomyelitis in which a stainless steel pin is coated with bioluminescent S. aureus and implanted transcortically through the tibial metaphysis, we discovered that mice protect themselves from this infection by mounting a specific IgG2b response against the peptidoglycan hydrolase, glucosaminidase (Gmd), an enzyme involved in cell wall digestion during binary fission. Since this subunit of S. aureus autolysin is essential for bacterial growth, and no genetic variation has been identified among clinical strains, we propose that monoclonal antibodies against this enzyme would have multiple mechanisms of action, including promotion of opsonophagocytosis and direct inhibition of enzyme function. Here we review the field of MRSA osteomyelitis and our research to date on the development of an anti-Gmd passive immunotherapy. PMID:22328866

  3. Regulation of the expression of the β-lactam antibiotic-resistance determinants in methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Blázquez, Blas; Llarrull, Leticia I; Luque-Ortega, Juan R; Alfonso, Carlos; Boggess, Bill; Mobashery, Shahriar

    2014-03-18

    β-Lactam antibiotics have faced obsolescence with the emergence of methicillin-resistant Staphylococcus aureus (MRSA). A complex set of events ensues upon exposure of MRSA to these antibiotics, which culminates in proteolysis of BlaI or MecI, two gene repressors, and results in the induction of resistance. We report studies on the mechanism of binding of these gene repressors to the operator regions by fluorescence anisotropy. Within the range of in vivo concentrations for BlaI and MecI, these proteins interact with their regulatory elements in a reversible manner, as both a monomer and a dimer. PMID:24564530

  4. Evaluation of rep-PCR/DiversiLab versus PFGE and spa typing in genotyping methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Aguadero, V; González Velasco, C; Vindel, A; Gonzalez Velasco, M; Moreno, J J

    2015-01-01

    Pulsed-field gel electrophoresis (PFGE) is the 'gold standard' for genotyping of methicillin-resistant Staphylococcus aureus (MRSA); however, the DiversiLab (DL) system, based on rep-PCR, is faster, simpler and could be better adapted to daily routine hospital work. We genotyped 100 MRSA isolates using PFGE, DL, and spa typing, and evaluated the discriminatory power of each technique and the correlation between them by Simpson's index(SI) and adjusted Rand coefficient (ARI), respectively. The isolates were from clinical samples from eight hospitals in Extremadura (Spain) during 2010. DL separated the 100 MRSA into 18 patterns, with 69% of the isolates grouped into four predominant patterns. spa typing reported 17 spa types, classifying 69% of MRSA into two major types (t067 and t002). PFGE revealed the existence of 27 patterns, gathering 54% of MRSA into three pulse types (E8a, E7a and E7b). SI values were 0.819, 0.726, 0.887 and 0.460 for DL, spa typing, PFGE and CC-BURP, respectively. ARI values of DL over PFGE, spa typing and CC-BURP were 0.151, 0.321 and 0.071, respectively. DL has less discriminatory power than PFGE but more than spa typing. The concordance of DL with PFGE is low, primarily because DL does not discriminate between the three predominant MRSA pulse types in our environment.

  5. Effectiveness of hospital-wide methicillin-resistant Staphylococcus aureus (MRSA) infection control policies differs by ward specialty.

    PubMed

    Sadsad, Rosemarie; Sintchenko, Vitali; McDonnell, Geoff D; Gilbert, Gwendolyn L

    2013-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of preventable nosocomial infections and is endemic in hospitals worldwide. The effectiveness of infection control policies varies significantly across hospital settings. The impact of the hospital context towards the rate of nosocomial MRSA infections and the success of infection control is understudied. We conducted a modelling study to evaluate several infection control policies in surgical, intensive care, and medical ward specialties, each with distinct ward conditions and policies, of a tertiary public hospital in Sydney, Australia. We reconfirm hand hygiene as the most successful policy and find it to be necessary for the success of other policies. Active screening for MRSA, patient isolation in single-bed rooms, and additional staffing were found to be less effective. Across these ward specialties, MRSA transmission risk varied by 13% and reductions in the prevalence and nosocomial incidence rate of MRSA due to infection control policies varied by up to 45%. Different levels of infection control were required to reduce and control nosocomial MRSA infections for each ward specialty. Infection control policies and policy targets should be specific for the ward and context of the hospital. The model we developed is generic and can be calibrated to represent different ward settings and pathogens transmitted between patients indirectly through health care workers. This can aid the timely and cost effective design of synergistic and context specific infection control policies.

  6. Evaluation of rep-PCR/DiversiLab versus PFGE and spa typing in genotyping methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Aguadero, V; González Velasco, C; Vindel, A; Gonzalez Velasco, M; Moreno, J J

    2015-01-01

    Pulsed-field gel electrophoresis (PFGE) is the 'gold standard' for genotyping of methicillin-resistant Staphylococcus aureus (MRSA); however, the DiversiLab (DL) system, based on rep-PCR, is faster, simpler and could be better adapted to daily routine hospital work. We genotyped 100 MRSA isolates using PFGE, DL, and spa typing, and evaluated the discriminatory power of each technique and the correlation between them by Simpson's index(SI) and adjusted Rand coefficient (ARI), respectively. The isolates were from clinical samples from eight hospitals in Extremadura (Spain) during 2010. DL separated the 100 MRSA into 18 patterns, with 69% of the isolates grouped into four predominant patterns. spa typing reported 17 spa types, classifying 69% of MRSA into two major types (t067 and t002). PFGE revealed the existence of 27 patterns, gathering 54% of MRSA into three pulse types (E8a, E7a and E7b). SI values were 0.819, 0.726, 0.887 and 0.460 for DL, spa typing, PFGE and CC-BURP, respectively. ARI values of DL over PFGE, spa typing and CC-BURP were 0.151, 0.321 and 0.071, respectively. DL has less discriminatory power than PFGE but more than spa typing. The concordance of DL with PFGE is low, primarily because DL does not discriminate between the three predominant MRSA pulse types in our environment. PMID:26510268

  7. Effectiveness of Hospital-Wide Methicillin-Resistant Staphylococcus aureus (MRSA) Infection Control Policies Differs by Ward Specialty

    PubMed Central

    Sadsad, Rosemarie; Sintchenko, Vitali; McDonnell, Geoff D.; Gilbert, Gwendolyn L.

    2013-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of preventable nosocomial infections and is endemic in hospitals worldwide. The effectiveness of infection control policies varies significantly across hospital settings. The impact of the hospital context towards the rate of nosocomial MRSA infections and the success of infection control is understudied. We conducted a modelling study to evaluate several infection control policies in surgical, intensive care, and medical ward specialties, each with distinct ward conditions and policies, of a tertiary public hospital in Sydney, Australia. We reconfirm hand hygiene as the most successful policy and find it to be necessary for the success of other policies. Active screening for MRSA, patient isolation in single-bed rooms, and additional staffing were found to be less effective. Across these ward specialties, MRSA transmission risk varied by 13% and reductions in the prevalence and nosocomial incidence rate of MRSA due to infection control policies varied by up to 45%. Different levels of infection control were required to reduce and control nosocomial MRSA infections for each ward specialty. Infection control policies and policy targets should be specific for the ward and context of the hospital. The model we developed is generic and can be calibrated to represent different ward settings and pathogens transmitted between patients indirectly through health care workers. This can aid the timely and cost effective design of synergistic and context specific infection control policies. PMID:24340085

  8. Tackling contamination of the hospital environment by methicillin-resistant Staphylococcus aureus (MRSA): a comparison between conventional terminal cleaning and hydrogen peroxide vapour decontamination.

    PubMed

    French, G L; Otter, J A; Shannon, K P; Adams, N M T; Watling, D; Parks, M J

    2004-05-01

    The hospital environment can sometimes harbour methicillin-resistant Staphylococcus aureus (MRSA) but is not generally regarded as a major source of MRSA infection. We conducted a prospective study in surgical wards of a London teaching hospital affected by MRSA, and compared the effectiveness of standard cleaning with a new method of hydrogen peroxide vapour decontamination. MRSA contamination, measured by surface swabbing was compared before and after terminal cleaning that complied with UK national standards, or hydrogen peroxide vapour decontamination. All isolation rooms, ward bays and bathrooms tested were contaminated with MRSA and several antibiogram types were identified. MRSA was common in sites that might transfer organisms to the hands of staff and was isolated from areas and bed frames used by non-MRSA patients. Seventy-four percent of 359 swabs taken before cleaning yielded MRSA, 70% by direct plating. After cleaning, all areas remained contaminated, with 66% of 124 swabs yielding MRSA, 74% by direct plating. In contrast, after exposing six rooms to hydrogen peroxide vapour, only one of 85 (1.2%) swabs yielded MRSA, by enrichment culture only. The hospital environment can become extensively contaminated with MRSA that is not eliminated by standard cleaning methods. In contrast, hydrogen peroxide vapour decontamination is a highly effective method of eradicating MRSA from rooms, furniture and equipment. Further work is needed to determine the importance of environmental contamination with MRSA and the effect on hospital infection rates of effective decontamination.

  9. MRSA Screening

    MedlinePlus

    ... be limited. Home Visit Global Sites Search Help? MRSA Screening Share this page: Was this page helpful? Formal name: Methicillin resistant Staphylococcus aureus Screening Related tests: Wound Culture At a Glance ...

  10. Molecular epidemiology of clinical and carrier strains of methicillin resistant Staphylococcus aureus (MRSA) in the hospital settings of north India

    PubMed Central

    Dar, Javid A; Thoker, Manzoor A; Khan, Jamal A; Ali, Asif; Khan, Mohammed A; Rizwan, Mohammed; Bhat, Khalid H; Dar, Mohammad J; Ahmed, Niyaz; Ahmad, Shamim

    2006-01-01

    Background The study was conducted between 2000 and 2003 on 750 human subjects, yielding 850 strains of staphylococci from clinical specimens (575), nasal cultures of hospitalized patients (100) and eye & nasal sources of hospital workers (50 & 125 respectively) in order to determine their epidemiology, acquisition and dissemination of resistance genes. Methods Organisms from clinical samples were isolated, cultured and identified as per the standard routine procedures. Susceptibility was measured by the agar diffusion method, as recommended by the Nat ional Committee for Clinical Laboratory Standards (NCCLS). The modified method of Birnboin and Takahashi was used for isolation of plasmids from staphylococci. Pulsed-field gel electrophoresis (PFGE) typing of clinical and carrier Methicillin resistant Staphylococcus aureus (MRSA) strains isolated during our study was performed as described previously. Results It was shown that 35.1% of Staphylococcus aureus and 22.5% of coagulase-negative staphylococcal isolates were resistant to methicillin. Highest percentage of MRSA (35.5%) was found in pus specimens (n = 151). The multiple drug resistance of all MRSA (n = 180) and Methicillin resistant Coagulase-negative Staphylococcus aureus (MRCNS) (n = 76) isolates was detected. In case of both methicillin-resistant as well as methicillin-sensitive Saphylococcal isolates zero resistance was found to vancomycin where as highest resistance was found to penicillin G followed by ampicillin. It was shown that the major reservoir of methicillin resistant staphylococci in hospitals are colonized/infected inpatients and colonized hospital workers, with carriers at risk for developing endogenous infection or transmitting infection to health care workers and patients. The results were confirmed by molecular typing using PFGE by SmaI-digestion. It was shown that the resistant markers G and T got transferred from clinical S. aureus (JS-105) to carrier S. aureus (JN-49) and the

  11. Impact of target site distribution for Type I restriction enzymes on the evolution of methicillin-resistant Staphylococcus aureus (MRSA) populations.

    PubMed

    Roberts, Gareth A; Houston, Patrick J; White, John H; Chen, Kai; Stephanou, Augoustinos S; Cooper, Laurie P; Dryden, David T F; Lindsay, Jodi A

    2013-08-01

    A limited number of Methicillin-resistant Staphylococcus aureus (MRSA) clones are responsible for MRSA infections worldwide, and those of different lineages carry unique Type I restriction-modification (RM) variants. We have identified the specific DNA sequence targets for the dominant MRSA lineages CC1, CC5, CC8 and ST239. We experimentally demonstrate that this RM system is sufficient to block horizontal gene transfer between clinically important MRSA, confirming the bioinformatic evidence that each lineage is evolving independently. Target sites are distributed randomly in S. aureus genomes, except in a set of large conjugative plasmids encoding resistance genes that show evidence of spreading between two successful MRSA lineages. This analysis of the identification and distribution of target sites explains evolutionary patterns in a pathogenic bacterium. We show that a lack of specific target sites enables plasmids to evade the Type I RM system thereby contributing to the evolution of increasingly resistant community and hospital MRSA.

  12. Effectual detection of group B streptococci with reduced penicillin susceptibility (PRGBS) by commercially available methicillin-resistant-Staphylococcus aureus (MRSA)-selective agar.

    PubMed

    Fukigai, Shinako; Morimoto, Makiko; Kimura, Kouji; Doyama, Yo; Miyazaki, Akira; Kamiya, Chitose; Banno, Hirotsugu; Morishima, Eriko; Onoda, Tomohiro; Nagano, Noriyuki; Jin, Wanchun; Wachino, Jun-Ichi; Yamada, Keiko; Arakawa, Yoshichika

    2016-07-01

    We evaluated the feasibility and efficacy of a commercially available methicillin-resistant Staphylococcus aureus (MRSA)-selective agar, chromID(™) MRSA, to detect group B streptococci with reduced penicillin susceptibility (PRGBS) in this study. The results showed 72.4% (21/29) sensitivity and 98.4% (60/61) specificity to detect PRGBS using this method.

  13. Surveillance of Physician-Diagnosed Skin and Soft Tissue Infections Consistent With Methicillin-Resistant "Staphylococcus aureus" (MRSA) among Nebraska High School Athletes, 2008-2012

    ERIC Educational Resources Information Center

    Buss, Bryan F.; Connolly, Susan

    2014-01-01

    Though historically confined to hospital settings, methicillin-resistant Staphylococcus aureus (MRSA) has received increasing attention in the wider community, particularly among athletes. A 2007-2008 investigation in Nebraska concluded that MRSA skin infections were an emerging problem among the state's student athletes. Statewide…

  14. The community prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in older people living in their own homes: implications for treatment, screening and surveillance in the UK.

    PubMed

    Maudsley, J; Stone, S P; Kibbler, C C; Iliffe, S R; Conaty, S J; Cookson, B D; Duckworth, G J; Johnson, A; Wallace, P G

    2004-07-01

    Methicillin-resistant Staphylococcus aureus (MRSA) predominantly affects those over 65 years old. There may be a substantial pool of older people with MRSA in the community. We studied the prevalence in one London general practice, screening 258 older people living in their own home. MRSA (E-MRSA 15) was found in two participants (0.78%). Past history of MRSA was the only significant risk factor. The results of this and other studies suggest that national guidelines recommending early discharge for MRSA carriers have not resulted in widespread community acquisition amongst elderly people living in their own home. Community antibiotic policies for skin and soft-tissue infection do not require amendment. Patients with previous MRSA should be isolated and screened on admission especially to high-risk units.

  15. Risk factors for methicillin-resistant Staphylococcus aureus skin and soft tissue infection in MRSA-colonized patients discharged from a Veterans Affairs hospital.

    PubMed

    Cadena, J; Richardson, A M; Frei, C R

    2016-02-01

    Currently, limited studies have quantified the risk of methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infections (SSTIs) for MRSA-colonized patients on discharge from hospital. Our retrospective, case-control study identified independent risk factors for the development of MRSA SSTIs among such patients detected by active MRSA nasal screening in an acute care hospital by PCR on admission, and bacteriological cultures on discharge. Cases were MRSA-colonized patients aged ⩾18 years who developed a MRSA SSTI post-discharge and controls were those who did not develop a MRSA SSTI post-discharge. Controls were matched to cases by length of follow-up (±10 days) for up to 18 months. Potential demographic and clinical risk factors for MRSA infection were identified using electronic queries and manual chart abstraction; data were compared by standard statistical tests and variables with P values ⩽0·05 in bivariable analysis were entered into a logistic regression model. Multivariable analysis demonstrated prior hospital admission within 12 months (P = 0·02), prior MRSA infection (P = 0·05), and previous myocardial infarction (P = 0·01) were independently predictive of a MRSA SSTI post-discharge. Identification of MRSA colonization upon admission and recognition of risk factors could help identify a high-risk population that could benefit from MRSA SSTI prevention strategies.

  16. Frequency of Aminoglycoside-Resistance Genes in Methicillin-Resistant Staphylococcus aureus (MRSA) Isolates from Hospitalized Patients

    PubMed Central

    Mahdiyoun, Seyed Mohsen; Kazemian, Hossein; Ahanjan, Mohammad; Houri, Hamidreza; Goudarzi, Mehdi

    2016-01-01

    Background Staphylococcus aureus is one of the most important causative agents in community- and hospital-acquired infections. Aminoglycosides are powerful bactericidal drugs that are often used in combination with beta-lactams or glycopeptides to treat staphylococcal infections. Objectives The main objective of the present study was to determine the prevalence of aminoglycoside resistance among methicillin-resistant Staphylococcus aureus (MRSA) isolates in hospitalized patients in Sari and Tehran, Iran. Methods In this study, 174 MRSA strains isolated from different clinical samples, such as blood, sputum, tracheal exudates, bronchus, pleura, urine, wounds, and catheters, were collected from hospitalized patients in Tehran and Sari during 2014. Antibiotic susceptibility testing was performed against nine antibiotics with the Kirby-Bauer disk diffusion method according to CLSI guidelines. The MRSA strains were examined with oxacillin and cefoxitin disks. MRSA was then validated by detection of the mecA gene. PCR was used to evaluate the prevalence of the aminoglycoside-resistance genes aac (6’)-Ie/aph (2”), aph (3’)-IIIa, and ant (4’) among the MRSA isolates. Results The results of drug susceptibility testing showed that the highest rate of resistance was against erythromycin in Tehran (84.4%) and gentamicin (71.7%) in Sari. All isolates were sensitive to vancomycin, and all strains harbored the mecA gene. The aac (6’)-Ie/aph (2”), aph (3’)-IIIa, and ant (4’)-Ia genes were detected among 134 (77%), 119 (68.4%), and 122 (70.1%) of the isolates, respectively. Conclusions The present study showed a high prevalence of aminoglycoside-resistance genes among MRSA isolates in two cities in Iran. PMID:27800135

  17. Nursing home characteristics associated with methicillin-resistant Staphylococcus aureus (MRSA) Burden and Transmission

    PubMed Central

    2012-01-01

    Background MRSA prevalence in nursing homes often exceeds that in hospitals, but reasons for this are not well understood. We sought to measure MRSA burden in a large number of nursing homes and identify facility characteristics associated with high MRSA burden. Methods We performed nasal swabs of residents from 26 nursing homes to measure MRSA importation and point prevalence, and estimate transmission. Using nursing home administrative data, we identified facility characteristics associated with MRSA point prevalence and estimated transmission risk in multivariate models. Results We obtained 1,649 admission and 2,111 point prevalence swabs. Mean MRSA point prevalence was 24%, significantly higher than mean MRSA admission prevalence, 16%, (paired t-test, p<0.001), with a mean estimated MRSA transmission risk of 16%. In multivariate models, higher MRSA point prevalence was associated with higher admission prevalence (p=0.005) and higher proportions of residents with indwelling devices (p=0.01). Higher estimated MRSA transmission risk was associated with higher proportions of residents with diabetes (p=0.01) and lower levels of social engagement (p=0.03). Conclusions MRSA importation was a strong predictor of MRSA prevalence, but MRSA burden and transmission were also associated with nursing homes caring for more residents with chronic illnesses or indwelling devices. Frequent social interaction among residents appeared to be protective of MRSA transmission, suggesting that residents healthy enough to engage in group activities do not incur substantial risks of MRSA from social contact. Identifying characteristics of nursing homes at risk for high MRSA burden and transmission may allow facilities to tailor infection control policies and interventions to mitigate MRSA spread. PMID:23095678

  18. THE FREQUENCY OF COMMUNITY-ACQUIRED METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS (CA-MRSA) AMONG SAMPLES IN INSTITUTE FOR PUBLIC HEALTH IN CANTON SARAJEVO

    PubMed Central

    Bektas, Sabaheta; Obradovic, Amina; Aljicevic, Mufida; Numanovic, Fatima; Hodzic, Dunja; Sporisevic, Lutvo

    2016-01-01

    Background: The increase in the incidence of methicillin-resistant Staphylococcus aureus (MRSA) infections lacking risk factors for exposure to the health care system has been associated with the recognition of new MRSA clones known as community-associated MRSA (CA-MRSA). These strains have been distinguished from health care-associated MRSA (HA-MRSA) strains by epidemiological, molecular and genetic means as well as by antibiotic susceptibility profile, tissue tropism and virulence traits. Objective: To assess prevalence and antibiotic susceptibility profile of CA-MRSA in Canton Sarajevo, Bosnia and Herzegovina. Results: Out of 1.905 positive Staphylococcus aureus isolates from various samples of outpatients collected during six months, 279 (14,64%) were MRSA isolates. Out of 279 MRSA samples, 133 (47,67%) were found in nasal swabs, from which 48 (36,09%) were in the age group <1 year and 39 (29,32 %) are in the age 1-5 year. Rate of the positive skin swabs was highest among the subject of age group <1 year (46 or 54,12 %) and 1-5 year (18 or 21,18 %). Predominantly antibiotic types among MRSA strains are resistant to penicillin and cefoxitin (36,90 %) and to penicillin, cefoxitin and erythromycin (61,35 %). Conclusion: Continued monitoring of epidemiology and emerging drug resistance data is critical for the effective management of these infections. PMID:27047271

  19. Risk factors for methicillin-resistant Staphylococcus aureus (MRSA) infection in dogs and cats: a case-control study

    PubMed Central

    Soares Magalhães, Ricardo Jorge; Loeffler, Anette; Lindsay, Jodi; Rich, Mick; Roberts, Larry; Smith, Heather; Lloyd, David Hugh; Pfeiffer, Dirk Udo

    2010-01-01

    Risk factors for methicillin-resistant Staphylococcus aureus (MRSA) infection in dogs and cats were investigated in an unmatched case-control study. A total of 197 animals from 150 veterinary practices across the United Kingdom was enrolled, including 105 MRSA cases and 92 controls with methicillin-susceptible S. aureus (MSSA) infection. The association of owners and veterinarian staff with the human healthcare sector (HCS) and animal-related characteristics such as signalment, antimicrobial and immunosuppressive therapy, and surgery were evaluated as putative risk factors using logistic regression. We found that significant risk factors for MRSA infection were the number of antimicrobial courses (p = 0.005), number of days admitted to veterinary clinics (p = 0.003) and having received surgical implants (p = 0.001). In addition, the odds of contact with humans which had been ill and admitted to hospital (p = 0.062) were higher in MRSA infected pets than in MSSA controls. The risk factors identified in this study highlight the need to increase vigilance towards identification of companion animal groups at risk and to advocate responsible and judicious use of antimicrobials in small animal practice. PMID:20423695

  20. Multicenter Evaluation of BBL CHROMagar MRSA Medium for Direct Detection of Methicillin-Resistant Staphylococcus aureus from Surveillance Cultures of the Anterior Nares

    PubMed Central

    Flayhart, Diane; Hindler, Janet F.; Bruckner, David A.; Hall, Geraldine; Shrestha, Rabin K.; Vogel, Sherilynn A.; Richter, Sandra S.; Howard, Wanita; Walther, Rhonda; Carroll, Karen C.

    2005-01-01

    Active surveillance for methicillin-resistant Staphylococcus aureus (MRSA) is among the strategies recommended by the Society for Healthcare Epidemiology of America for control of nosocomial MRSA infections. Infection control and laboratory personnel desire rapid, sensitive, and inexpensive methods to enhance surveillance activities. A multicenter study was performed to evaluate a new selective and differential chromogenic medium, BBL CHROMagar MRSA (C-MRSA) medium (BD Diagnostics, Sparks, MD), which enables recovery and concomitant identification of MRSA strains directly from nasal swab specimens taken from the anterior nares. Specimens were inoculated to C-MRSA and Trypticase soy agar with 5% sheep blood agar (TSA II, BD Diagnostics). Mauve colonies on C-MRSA at 24 h and 48 h and suspicious colonies on TSA II were confirmed as Staphylococcus aureus by Gram stain morphology and a coagulase test. In addition, the results of C-MRSA were compared to results of susceptibility testing (five different methods) of S. aureus strains isolated on TSA II. A total of 2,015 specimens were inoculated to C-MRSA and TSA II. Three hundred fifty-four S. aureus isolates were recovered; 208 (59%) were oxacillin (methicillin) susceptible and 146 (41%) were oxacillin resistant (MRSA). On C-MRSA, 139/146 or 95.2% of MRSA isolates were recovered, whereas recovery on TSA II was 86.9% (127/146) (P = 0.0027). The overall specificity of C-MRSA was 99.7%. When C-MRSA was compared to each susceptibility testing method, the sensitivity and specificity, respectively, were as follows: oxacillin MIC by broth microdilution, 94.4% and 96.7%; oxacillin screen agar, 94.3% and 96.7%; PBP2′ latex agglutination, 93.7% and 98.5%; cefoxitin disk diffusion, 95.0% and 98.1%; and mecA PCR, 95.1% and 98.1%. In this study, C-MRSA was superior to TSA II for recovery of MRSA from surveillance specimens obtained from the anterior nares and was comparable to conventional, rapid, and molecular susceptibility

  1. Comparative genomic analysis of Staphylococcus aureus FORC_001 and S. aureus MRSA252 reveals the characteristics of antibiotic resistance and virulence factors for human infection.

    PubMed

    Lim, Sooyeon; Lee, Dong-Hoon; Kwak, Woori; Shin, Hakdong; Ku, Hye-Jin; Lee, Jong-Eun; Lee, Gun Eui; Kim, Heebal; Choi, Sang-Ho; Ryu, Sangryeol; Lee, Ju-Hoon

    2015-01-01

    Staphylococcus aureus is an important foodborne pathogen that causes diverse diseases ranging from minor infections to life-threatening conditions in humans and animals. To further understand its pathogenesis, the genome of the strain S. aureus FORC_001 was isolated from a contaminated food. Its genome consists of 2,886,017 bp double-stranded DNA with a GC content of 32.8%. It is predicted to contain 2,728 open reading frames, 57 tRNAs, and 6 rRNA operons, including 1 additional 5S rRNA gene. Comparative phylogenetic tree analysis of 40 complete S. aureus genome sequences using average nucleotide identity (ANI) revealed that strain FORC_001 belonged to Group I. The closest phylogenetic match was S. aureus MRSA252, according to a whole-genome ANI (99.87%), suggesting that they might share a common ancestor. Comparative genome analysis of FORC_001 and MRSA252 revealed two non-homologous regions: Regions I and II. The presence of various antibiotic resistance genes, including the SCCmec cluster in Region I of MRSA252, suggests that this strain might have acquired the SCCmec cluster to adapt to specific environments containing methicillin. Region II of both genomes contains prophage regions but their DNA sequence identity is very low, suggesting that the prophages might differ. This is the first report of the complete genome sequence of S. aureus isolated from a real foodborne outbreak in South Korea. This report would be helpful to extend our understanding about the genome, general characteristics, and virulence factors of S. aureus for further studies of pathogenesis, rapid detection, and epidemiological investigation in foodborne outbreak.

  2. Analysis of reporting time for identification of methicillin-resistant Staphylococcus aureus carriers using ChromID MRSA.

    PubMed

    Lee, Yirang; Kim, Jae-Seok; Kim, Han-Sung; Kim, Hyun Soo; Song, Wonkeun; Lee, Kyu Man

    2014-05-01

    We assessed the reporting times for identification of nasal methicillin-resistant Staphylococcus aureus (MRSA) carriers in 2011 in a university-affiliated hospital using surveillance cultures incubated for 1 and 2 days with ChromID MRSA (bioMérieux, France). Of 2,732 nasal swabs tested, MRSA was detected in 829 (85.6%) and 140 (14.4%) swabs after 1 and 2 days of incubation, respectively, and the median reporting times for positive specimens were 33.7 hr (range, 18.2-156.9 hr) and 108.1 hr (range, 69.8-181.0 hr), respectively. Detection rate after 1-day incubation was 85%. Additional 1-day incubation improved detection rate; however, it prolonged the reporting times of positive specimens approximately up to 4 days because of the need for confirmatory tests such as species identification and susceptibility tests. Following a 2-day culture with ChromID MRSA, rapid confirmatory tests are warranted to reduce delay in identifying MRSA carriers.

  3. Potential therapeutic drug target identification in Community Acquired-Methicillin Resistant Staphylococcus aureus (CA-MRSA) using computational analysis.

    PubMed

    Yadav, Pramod Kumar; Singh, Gurmit; Singh, Satendra; Gautam, Budhayash; Saad, Esmaiel If

    2012-01-01

    The emergence of multidrug-resistant strain of community-acquired methicillin resistant Staphylococcus aureus (CA-MRSA) strain has highlighted the urgent need for the alternative and effective therapeutic approach to combat the menace of this nosocomial pathogen. In the present work novel potential therapeutic drug targets have been identified through the metabolic pathways analysis. All the gene products involved in different metabolic pathways of CA-MRSA in KEGG database were searched against the proteome of Homo sapiens using the BLASTp program and the threshold of E-value was set to as 0.001. After database searching, 152 putative targets were identified. Among all 152 putative targets, 39 genes encoding for putative targets were identified as the essential genes from the DEG database which are indispensable for the survival of CA-MRSA. After extensive literature review, 7 targets were identified as potential therapeutic drug target. These targets are Fructose-bisphosphate aldolase, Phosphoglyceromutase, Purine nucleoside phosphorylase, Uridylate kinase, Tryptophan synthase subunit beta, Acetate kinase and UDP-N-acetylglucosamine 1-carboxyvinyltransferase. Except Uridylate kinase all the identified targets were involved in more than one metabolic pathways of CA-MRSA which underlines the importance of drug targets. These potential therapeutic drug targets can be exploited for the discovery of novel inhibitors for CA-MRSA using the structure based drug design (SBDD) strategy.

  4. The bactericidal effect of 470 nm light and hyperbaric oxygen on methicillin-resistant Staphylococcus aureus (MRSA)

    PubMed Central

    Bumah, Violet Vakunseh; Whelan, Harry Thomas; Masson-Meyers, Daniela Santos; Quirk, Brendan; Buchmann, Ellen; Enwemeka, Chukuka Samuel

    2015-01-01

    It has been shown that, in vitro, hyperbaric oxygen (HBO) suppresses 28% bacterial growth, while 470 nm blue light alone suppresses up to 92% methicillin resistant Staphylococcus aureus (MRSA) in one application in vitro. Therefore, we determined if combined 470 nm light (55 J/cm2) and HBO will yield 100% bacterial suppression in experimental simulation of mild, moderate or severe MRSA infection. We cultured MRSA at 3×106, 5×106, 7×106, 8×106 or 12×106 CFU/ml and treated each concentration in four groups as follows: (1) Control (no treatment) (2) photo-irradiation only, (3) photo-irradiation then HBO, (4) HBO only, and (5) HBO then photo-irradiation. Bacteria colonies were then quantified. The results showed that at each bacterial concentration, HBO alone was significantly less effective in suppressing MRSA than photo-irradiation or combined HBO and photo-irradiation (p<0.0001). Similarly, at no bacterial concentration did combined HBO and 470 nm light treatment yield a statistically better result than 470 nm light alone (p > 0.05), neither did HBO treatment either before or after irradiation make a difference. Furthermore, at no bacterial concentration was 100% MRSA suppression achieved. Indeed, the maximum bacterial suppression attained was in the mild infection model (3×106 CFU/ml), with blue light producing 97.3±0.2% suppression and HBO +55 J/cm2 yielding 97.5±2.5% suppression. We conclude that: (1) HBO and 470 nm light individually suppress MRSA growth; (2) 470nm blue light is more effective in suppressing MRSA than HBO; and (3) HBO did not act synergistically to heighten the bactericidal effect of 470 nm light. PMID:25700768

  5. Emerging ST121/agr4 community-associated methicillin-resistant Staphylococcus aureus (MRSA) with strong adhesin and cytolytic activities: trigger for MRSA pneumonia and fatal aspiration pneumonia in an influenza-infected elderly.

    PubMed

    Wan, T-W; Tomita, Y; Saita, N; Konno, K; Iwao, Y; Hung, W-C; Teng, L-J; Yamamoto, T

    2016-09-01

    The pathogenesis of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) pneumonia in influenza-infected elderly individuals has not yet been elucidated in detail. In the present study, a 92-year-old man infected with influenza developed CA-MRSA pneumonia. His CA-MRSA was an emerging type, originated in ST121/agr4 S. aureus, with diversities of Panton-Valentine leucocidin (PVL)(-)/spat5110/SCCmecV(+) versus PVL(+)/spat159((etc.))/SCCmec (-), but with common virulence potentials of strong adhesin and cytolytic activities. Resistance to erythromycin/clindamycin (inducible-type) and gentamicin was detected. Pneumonia improved with the administration of levofloxacin, but with the subsequent development of fatal aspiration pneumonia. Hence, characteristic CA-MRSA with strong adhesin and cytolytic activities triggered influenza-related sequential complications.

  6. GenomEra MRSA/SA, a fully automated homogeneous PCR assay for rapid detection of Staphylococcus aureus and the marker of methicillin resistance in various sample matrixes.

    PubMed

    Hirvonen, Jari J; Kaukoranta, Suvi-Sirkku

    2013-09-01

    The GenomEra MRSA/SA assay (Abacus Diagnostica, Turku, Finland) is the first commercial homogeneous PCR assay using thermally stable, intrinsically fluorescent time-resolved fluorometric (TRF) labels resistant to autofluorescence and other background effects. This fully automated closed tube PCR assay simultaneously detects Staphylococcus aureus specific DNA and the mecA gene within 50 min. It can be used for both screening and confirmation of methicillin-resistant and -sensitive S. aureus (MRSA and MSSA) directly in different specimen types or from preceding cultures. The assay has shown excellent performance in comparisons with other diagnostic methods in all the sample types tested. The GenomEra MRSA/SA assay provides rapid assistance for the detection of MRSA as well as invasive staphylococcal infections and helps the early targeting of antimicrobial therapy to patients with potential MRSA infection.

  7. Trends in annual incidence of methicillin-resistant Staphylococcus aureus (MRSA) infection in HIV-infected and HIV-uninfected patients.

    PubMed

    Delorenze, G N; Horberg, M A; Silverberg, M J; Tsai, A; Quesenberry, C P; Baxter, R

    2013-11-01

    We describe trends in incidence rates of methicillin-resistant Staphylococcus aureus (MRSA) in HIV-infected and HIV-uninfected patients enrolled in a large northern California Health Plan, and the ratio of MRSA to methicillin-susceptible S. aureus (MSSA) case counts. Between 1995 and 2010, 1549 MRSA infections were diagnosed in 14060 HIV-infected patients (11·0%) compared to 89546 MRSA infections in 6597396 HIV-uninfected patients (1·4%) (P = 0·00). A steady rise in MRSA infection rates began in 1995 in HIV-uninfected patients, peaking at 396·5 infections/100000 person-years in 2007. A more rapid rise in MRSA infection rates occurred in the HIV-infected group after 2000, peaking at 3592·8 infections/100000 in 2005. A declining trend in MRSA rates may have begun in 2008-2009. Comparing the ratio of MRSA to MSSA case counts, we observed that HIV-infected patients shouldered a greater burden of MRSA infection during most years of study follow-up compared to HIV-uninfected patients.

  8. First reporting of methicillin-resistant Staphylococcus aureus (MRSA) ST398 in an industrial rabbit holding and in farm-related people.

    PubMed

    Agnoletti, Fabrizio; Mazzolini, Elena; Bacchin, Cosetta; Bano, Luca; Berto, Giacomo; Rigoli, Roberto; Muffato, Giovanna; Coato, Paola; Tonon, Elena; Drigo, Ilenia

    2014-05-14

    Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) has been described in food-producing animals and farm or slaughterhouse workers involved in the primary industrial production of swine, bovine and poultry. This communication describes the first case of LA-MRSA (ST398, spa types t034 and t5210) occurring in rabbits raised intensively for meat production and involving farm workers or their family members. In 2012-2013, in a study involving 40 rabbit industrial holdings in Italy, one farm was found to have rabbits colonized or infected with MRSA. Four farm workers and one of their relatives were found to be carrying MRSA. In this case holding, rabbits, people and the holding environment were further investigated and followed up by a second sampling five months later. MRSA was found in 48% (11/23) and 25% (15/59) of the rabbits carrying S. aureus at first and second samplings, respectively. Five months after first detection, some farm workers or family members were still MRSA carriers. Surface samples (2/10) and air samples (2/3) were contaminated with MRSA. Air samples yielded MRSA counts of 5 and 15CFU/m(3). MRSA from rabbits and people collected at first sampling were spa types t034 and t5210 belonging to ST398. The MRSA isolates from rabbits and persons tested at second sampling were t034 and t5210, but spa types t1190 and t2970 were also detected in MRSA isolates from rabbits. Tracing the epidemiological pattern earlier may prevent further spread of LA-MRSA in these food producing animals.

  9. Isolation of Methicillin-Resistant Staphylococcus aureus (MRSA) from HIV Patients Referring to HIV Referral Center, Shiraz, Iran, 2011-2012.

    PubMed

    Hassanzadeh, Parvin; Hassanzadeh, Yashgin; Mardaneh, Jalal; Rezai, Esmaeel; Motamedifar, Mohammad

    2015-11-01

    Extension of drug resistant Staphylococcus aureus strains is one of the problems of modern society. Presence of methicillin-resistant Staphylococcus aureus (MRSA) in HIV-infected individuals is an important cause of severe infections. Therefore, the main goal of this study was to determine the prevalence rate of MRSA carriage rate among HIV patients referring to the Shiraz HIV referral center (Shiraz, Iran) during 2011-2012. Nasal swabs were obtained from HIV positive patients and were cultured on differential and selective media to isolate Staphylococcus aureus, which was confirmed by standard biochemical tests. For isolation of MRSA isolates, bacterial suspensions were cultured on Muller-Hinton Agar containing NaCl and Oxacillin. Finally, data were analyzed by the SPSS software. Of 180 HIV patients, MRSA was isolated from nasal cavity of 23 (12.8%) patients. Most of the isolates were recovered from male subjects who were under 40 years old. No variables such as skin disease, history of hospitalization or infectious disease had significant association with the MRSA colonization rate. The presence of MRSA isolates in the nasal cavity of HIV patients in such a rate warns us about the potential spreading of MRSA among HIV patients in our society and emphasizes on establishing better prevention strategies.

  10. Isolation of Methicillin-Resistant Staphylococcus aureus (MRSA) from HIV Patients Referring to HIV Referral Center, Shiraz, Iran, 2011-2012

    PubMed Central

    Hassanzadeh, Parvin; Hassanzadeh, Yashgin; Mardaneh, Jalal; Rezai, Esmaeel; Motamedifar, Mohammad

    2015-01-01

    Extension of drug resistant Staphylococcus aureus strains is one of the problems of modern society. Presence of methicillin-resistant Staphylococcus aureus (MRSA) in HIV-infected individuals is an important cause of severe infections. Therefore, the main goal of this study was to determine the prevalence rate of MRSA carriage rate among HIV patients referring to the Shiraz HIV referral center (Shiraz, Iran) during 2011-2012. Nasal swabs were obtained from HIV positive patients and were cultured on differential and selective media to isolate Staphylococcus aureus, which was confirmed by standard biochemical tests. For isolation of MRSA isolates, bacterial suspensions were cultured on Muller-Hinton Agar containing NaCl and Oxacillin. Finally, data were analyzed by the SPSS software. Of 180 HIV patients, MRSA was isolated from nasal cavity of 23 (12.8%) patients. Most of the isolates were recovered from male subjects who were under 40 years old. No variables such as skin disease, history of hospitalization or infectious disease had significant association with the MRSA colonization rate. The presence of MRSA isolates in the nasal cavity of HIV patients in such a rate warns us about the potential spreading of MRSA among HIV patients in our society and emphasizes on establishing better prevention strategies. PMID:26538782

  11. Update on the prevention and control of community-acquired meticillin-resistant Staphylococcus aureus (CA-MRSA).

    PubMed

    Skov, Robert; Christiansen, Keryn; Dancer, Stephanie J; Daum, Robert S; Dryden, Matthew; Huang, Yhu-Chering; Lowy, Franklin D

    2012-03-01

    The rapid dissemination of community-acquired meticillin-resistant Staphylococcus aureus (CA-MRSA) since the early 2000s and the appearance of new successful lineages is a matter of concern. The burden of these infections varies widely between different groups of individuals and in different regions of the world. Estimating the total burden of disease is therefore problematic. Skin and soft-tissue infections, often in otherwise healthy young individuals, are the most common clinical manifestation of these infections. The antibiotic susceptibilities of these strains also vary, although they are often more susceptible to 'traditional' antibiotics than related hospital-acquired strains. Preventing the dissemination of these organisms throughout the general population requires a multifaceted approach, including screening and decolonisation, general hygiene and cleaning measures, antibiotic stewardship programmes and, in the future, vaccination. The current evidence on the prevention and control of CA-MRSA is appraised and summarised in this review.

  12. Staphylococcal enterotoxin B toxic shock syndrome induced by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA).

    PubMed

    Kashiwada, Takeru; Kikuchi, Ken; Abe, Shinji; Kato, Hidehito; Hayashi, Hiroki; Morimoto, Taisuke; Kamio, Koichiro; Usuki, Jiro; Takeda, Shinhiro; Tanaka, Keiji; Imanishi, Ken'ichi; Yagi, Junji; Azuma, Arata; Gemma, Akihiko

    2012-01-01

    We herein report a case of toxic shock syndrome (TSS) associated with the 2009 pandemic H1N1 (pH1N1) influenza virus and a community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infection in a 16-year-old Vietnamese girl. Staphylococcal enterotoxin B (SEB) was detected in the patient's serum, and the level of anti-SEB antibodies was found to be elevated. A flow cytometric analysis showed evidence of activated SEB-reactive Vβ3+ and Vβ12+ T cells. These data suggest that the CA-MRSA-induced activation of SEB-reactive T cells may cause TSS in patients with pH1N1 virus infection. Moreover, this is the first report describing immunological confirmation of SEB contributing directly to TSS in a patient fulfilling the diagnostic criteria of TSS.

  13. Rifampicin-fosfomycin coating for cementless endoprostheses: antimicrobial effects against methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Alt, Volker; Kirchhof, Kristin; Seim, Florian; Hrubesch, Isabelle; Lips, Katrin S; Mannel, Henrich; Domann, Eugen; Schnettler, Reinhard

    2014-10-01

    New strategies to decrease infection rates in cementless arthroplasty are needed, especially in the context of the growing incidence of methicillin-resistant Staphylococcus aureus (MRSA) infections. The purpose of this study was to investigate the antimicrobial activity of a rifampicin-fosfomycin coating against methicillin-sensitive Staphylococcus aureus (MSSA) and MRSA in a rabbit infection prophylaxis model. Uncoated or rifampicin-fosfomycin-coated K-wires were inserted into the intramedullary canal of the tibia in rabbits and contaminated with an inoculation dose of 10(5) or 10(6) colony-forming units of MSSA EDCC 5055 in study 1 and MRSA T6625930 in study 2, respectively. After 28days the animals were killed and clinical, histological and microbiological assessment, including pulse-field gel electrophoresis, was conducted. Positive culture growth in agar plate testing and/or clinical signs and/or histological signs were defined positive for infection. Statistical evaluation was performed using Fisher's exact test. Both studies showed a statistically significant reduction of infection rates for rifampicin-fosfomycin-coated implants compared to uncoated K-wires (P=0.015). In both studies none of the 12 animals that were treated with a rifampicin-fosfomycin-coated implant showed clinical signs of infection or a positive agar plate testing result. In both studies, one animal of the coating group showed the presence of sporadic bacteria with concomitant inflammatory signs in histology. The control groups in both studies exhibited an infection rate of 100% with clear clinical signs of infection and positive culture growth in all animals. In summary, the rifampicin-fosfomycin-coating showed excellent antimicrobial activity against both MSSA and MRSA, and therefore warrants further clinical testing.

  14. The use of vancomycin in the treatment of adult patients with methicillin-resistant Staphylococcus aureus (MRSA) infection: a survey in a tertiary hospital in China

    PubMed Central

    Tang, Jing; Hu, Jiali; Kang, Lei; Deng, Zhengjun; Wu, Jiaofen; Pan, Jiaqian

    2015-01-01

    Background: Vancomycin is frequently used in the treatment of methicillin-resistant Staphylococcus aureus (MRSA). Objectives: To determine MRSA infection status and the use of vancomycin in its treatment at a teaching hospital in China. Methods: We retrospectively reviewed 140 cases of MRSA infection that were treated from January 2013 to October 2014. We analyzed the etiology of MRSA infection and the use of vancomycin in these cases. Results: MRSA infection mainly occurred in elderly patients concomitant with a variety of diseases, which incidence was more in men than women. More cases of MRSA infection were encountered in the ICU than in other departments. The positive culture results for MRSA were obtained in the sputum (38.57%), pharyngeal swab (19.29%), blood (5.71%), and wound secretion (11.43%) samples. The MRSA patients were sensitive to vancomycin, with the minimum inhibitory concentration (MIC) being 1 μg/mL in 53.80% of the cases and 2 μg/mL in 44.10% of the cases, respectively. Among the 35 (25%) cases treated with vancomycin, 23 were cured, while 3 died and 7 (20%) were considered as an unreasonable application. Conclusions: MRSA infection mainly appeared in patients admitted to the ICU. The MIC of vancomycin had a tendency to increase gradually. PMID:26770588

  15. The bactericidal effect of 470-nm light and hyperbaric oxygen on methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Bumah, Violet Vakunseh; Whelan, Harry Thomas; Masson-Meyers, Daniela Santos; Quirk, Brendan; Buchmann, Ellen; Enwemeka, Chukuka Samuel

    2015-04-01

    It has been shown that, in vitro, hyperbaric oxygen (HBO) suppresses 28 % bacterial growth, while 470-nm blue light alone suppresses up to 92 % methicillin-resistant Staphylococcus aureus (MRSA) in one application in vitro. Therefore, we determined if combined 470-nm light (55 J/cm(2)) and HBO will yield 100 % bacterial suppression in experimental simulation of mild, moderate or severe MRSA infection. We cultured MRSA at 3 × 10(6), 5 × 10(6), 7 × 10(6), 8 × 10(6), or 12 × 10(6) CFU/ml and treated each concentration in four groups as follows: (1) control (no treatment) (2) photo-irradiation only, (3) photo-irradiation then HBO, (4) HBO only, and (5) HBO then photo-irradiation. Bacteria colonies were then quantified. The results showed that at each bacterial concentration, HBO alone was significantly less effective in suppressing MRSA than photo-irradiation or combined HBO and photo-irradiation (p < 0.0001). Similarly, at no bacterial concentration did combined HBO and 470-nm light treatment yield a statistically better result than 470-nm light alone (p > 0.05), neither did HBO treatment either before or after irradiation make a difference. Furthermore, at no bacterial concentration was 100 % MRSA suppression achieved. Indeed, the maximum bacterial suppression attained was in the mild infection model (3 × 10(6) CFU/ml), with blue light producing 97.3 ± 0.2 % suppression and HBO + 55 J/cm(2) yielding 97.5 ± 2.5 % suppression. We conclude that (1) HBO and 470-nm light individually suppress MRSA growth; (2) 470-nm blue light is more effective in suppressing MRSA than HBO; and (3) HBO did not act synergistically to heighten the bactericidal effect of 470-nm light.

  16. Epidemiological features, resistance genes, and clones among community-onset methicillin-resistant Staphylococcus aureus (CO-MRSA) isolates detected in northern Spain.

    PubMed

    González-Domínguez, María; Seral, Cristina; Sáenz, Yolanda; Salvo, Soledad; Gude, María José; Porres-Osante, Nerea; Torres, Carmen; Castillo, Francisco Javier

    2012-12-01

    Twenty-nine community-onset methicillin-resistant Staphylococcus aureus (CO-MRSA) isolates were prospectively selected according to epidemiological criteria among 374 MRSA isolates collected in our laboratory during 2009-2010 in order to determine which community-associated MRSA (CA-MRSA) and healthcare-associated MRSA (HA-MRSA) clones are circulating in the community in northern Spain. PVL genes were detected in 5 strains (17.2%) that belonged to SCCmec type IV or V and to the agr group I (ST8 and ST2050), agr group II (ST121), and agr group III (ST30 and ST852). These strains were isolated from patients with different clinical manifestations such as urinary tract infection, abscess, or pneumonia, and most of them belonged to emergency department patients with no history of visits to General Practitioners (GPs) in the year before the isolation. We considered that the prevalence of CA-MRSA in community-onset isolates was low (17.2%). A high proportion of the CO-MRSA strains (58.6%) were ST125-MRSA-IVc (CC5), responsible for most of the infections caused by HA-MRSA strains in Spain. This endemic clone is also circulating in the community of northern Spain as we could demonstrate in this study. Antimicrobial resistance was found in spa type t067 isolates linked to the presence of ant(4')-Ia and msr(A). Most of the CO-MRSA isolates in this study corresponded to spa types more associated to the hospital environment, suggesting the interchange of genetic lineages of MRSA among community and hospital niches.

  17. High incidence of oxacillin-susceptible mecA-positive Staphylococcus aureus (OS-MRSA) associated with bovine mastitis in China.

    PubMed

    Pu, WanXia; Su, Yang; Li, JianXi; Li, ChunHui; Yang, ZhiQiang; Deng, HaiPing; Ni, ChunXia

    2014-01-01

    Staphylococcus aureus is a main cause of bovine mastitis and a major pathogen affecting human health. The emergence and spread of methicillin-resistant Staphylococcus aureus (MRSA) has become a significant concern for both animal health and public health. This study investigated the incidence of MRSA in milk samples collected from dairy cows with clinical mastitis and characterized the MRSA isolates using antimicrobial susceptibility tests and genetic typing methods. In total, 103 S. aureus isolates were obtained from dairy farms in 4 different provinces in China, including Gansu, Shanghai, Sichuan, and Guizhou. Antimicrobial susceptibility testing of these isolates revealed that the resistance rates to penicillin and sulfamethoxazole were high, while the resistance rates to ciprofloxacin and vancomycin were low. Among the 103 isolates, 49 (47.6%) were found to be mecA-positive, indicating the high incidence of MRSA. However, 37 of the 49 mecA-positive isolates were susceptible to oxacillin as determined by antimicrobial susceptibility assays and were thus classified as oxacillin-susceptible mecA-positive S. aureus (OS-MRSA). These isolates could be misclassified as methicillin susceptible Staphylococcus aureus (MSSA) if genetic detection of mecA was not performed. Molecular characterization of selected mecA-positive isolates showed that they were all negative with Panton-Valentine leukocidin (PVL), but belonged to different spa types and SCCmec types. These results indicate that OS-MRSA is common in bovine mastitis in China and underscore the need for genetic methods (in addition to phenotypic tests) to accurately identify MRSA.

  18. Healthcare- and Community-Associated Methicillin-Resistant Staphylococcus aureus (MRSA) and Fatal Pneumonia with Pediatric Deaths in Krasnoyarsk, Siberian Russia: Unique MRSA's Multiple Virulence Factors, Genome, and Stepwise Evolution.

    PubMed

    Khokhlova, Olga E; Hung, Wei-Chun; Wan, Tsai-Wen; Iwao, Yasuhisa; Takano, Tomomi; Higuchi, Wataru; Yachenko, Svetlana V; Teplyakova, Olga V; Kamshilova, Vera V; Kotlovsky, Yuri V; Nishiyama, Akihito; Reva, Ivan V; Sidorenko, Sergey V; Peryanova, Olga V; Reva, Galina V; Teng, Lee-Jene; Salmina, Alla B; Yamamoto, Tatsuo

    2015-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a common multidrug-resistant (MDR) pathogen. We herein discussed MRSA and its infections in Krasnoyarsk, Siberian Russia between 2007 and 2011. The incidence of MRSA in 3,662 subjects was 22.0% and 2.9% for healthcare- and community-associated MRSA (HA- and CA-MRSA), respectively. The 15-day mortality rates for MRSA hospital- and community-acquired pneumonia (HAP and CAP) were 6.5% and 50%, respectively. MRSA CAP cases included pediatric deaths; of the MRSA pneumonia episodes available, ≥27.3% were associated with bacteremia. Most cases of HA-MRSA examined exhibited ST239/spa3(t037)/SCCmecIII.1.1.2 (designated as ST239Kras), while all CA-MRSA cases examined were ST8/spa1(t008)/SCCmecIV.3.1.1(IVc) (designated as ST8Kras). ST239Kras and ST8Kras strongly expressed cytolytic peptide (phenol-soluble modulin α, PSMα; and δ-hemolysin, Hld) genes, similar to CA-MRSA. ST239Kras pneumonia may have been attributed to a unique set of multiple virulence factors (MVFs): toxic shock syndrome toxin-1 (TSST-1), elevated PSMα/Hld expression, α-hemolysin, the staphylococcal enterotoxin SEK/SEQ, the immune evasion factor SCIN/SAK, and collagen adhesin. Regarding ST8Kras, SEA was included in MVFs, some of which were common to ST239Kras. The ST239Kras (strain OC3) genome contained: a completely unique phage, φSa7-like (W), with no att repetition; S. aureus pathogenicity island SaPI2R, the first TSST-1 gene-positive (tst+) SaPI in the ST239 lineage; and a super copy of IS256 (≥22 copies/genome). ST239Kras carried the Brazilian SCCmecIII.1.1.2 and United Kingdom-type tst. ST239Kras and ST8Kras were MDR, with the same levofloxacin resistance mutations; small, but transmissible chloramphenicol resistance plasmids spread widely enough to not be ignored. These results suggest that novel MDR and MVF+ HA- and CA-MRSA (ST239Kras and ST8Kras) emerged in Siberian Russia (Krasnoyarsk) associated with fatal pneumonia, and also with ST

  19. Healthcare- and Community-Associated Methicillin-Resistant Staphylococcus aureus (MRSA) and Fatal Pneumonia with Pediatric Deaths in Krasnoyarsk, Siberian Russia: Unique MRSA's Multiple Virulence Factors, Genome, and Stepwise Evolution.

    PubMed

    Khokhlova, Olga E; Hung, Wei-Chun; Wan, Tsai-Wen; Iwao, Yasuhisa; Takano, Tomomi; Higuchi, Wataru; Yachenko, Svetlana V; Teplyakova, Olga V; Kamshilova, Vera V; Kotlovsky, Yuri V; Nishiyama, Akihito; Reva, Ivan V; Sidorenko, Sergey V; Peryanova, Olga V; Reva, Galina V; Teng, Lee-Jene; Salmina, Alla B; Yamamoto, Tatsuo

    2015-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a common multidrug-resistant (MDR) pathogen. We herein discussed MRSA and its infections in Krasnoyarsk, Siberian Russia between 2007 and 2011. The incidence of MRSA in 3,662 subjects was 22.0% and 2.9% for healthcare- and community-associated MRSA (HA- and CA-MRSA), respectively. The 15-day mortality rates for MRSA hospital- and community-acquired pneumonia (HAP and CAP) were 6.5% and 50%, respectively. MRSA CAP cases included pediatric deaths; of the MRSA pneumonia episodes available, ≥27.3% were associated with bacteremia. Most cases of HA-MRSA examined exhibited ST239/spa3(t037)/SCCmecIII.1.1.2 (designated as ST239Kras), while all CA-MRSA cases examined were ST8/spa1(t008)/SCCmecIV.3.1.1(IVc) (designated as ST8Kras). ST239Kras and ST8Kras strongly expressed cytolytic peptide (phenol-soluble modulin α, PSMα; and δ-hemolysin, Hld) genes, similar to CA-MRSA. ST239Kras pneumonia may have been attributed to a unique set of multiple virulence factors (MVFs): toxic shock syndrome toxin-1 (TSST-1), elevated PSMα/Hld expression, α-hemolysin, the staphylococcal enterotoxin SEK/SEQ, the immune evasion factor SCIN/SAK, and collagen adhesin. Regarding ST8Kras, SEA was included in MVFs, some of which were common to ST239Kras. The ST239Kras (strain OC3) genome contained: a completely unique phage, φSa7-like (W), with no att repetition; S. aureus pathogenicity island SaPI2R, the first TSST-1 gene-positive (tst+) SaPI in the ST239 lineage; and a super copy of IS256 (≥22 copies/genome). ST239Kras carried the Brazilian SCCmecIII.1.1.2 and United Kingdom-type tst. ST239Kras and ST8Kras were MDR, with the same levofloxacin resistance mutations; small, but transmissible chloramphenicol resistance plasmids spread widely enough to not be ignored. These results suggest that novel MDR and MVF+ HA- and CA-MRSA (ST239Kras and ST8Kras) emerged in Siberian Russia (Krasnoyarsk) associated with fatal pneumonia, and also with ST

  20. Healthcare- and Community-Associated Methicillin-Resistant Staphylococcus aureus (MRSA) and Fatal Pneumonia with Pediatric Deaths in Krasnoyarsk, Siberian Russia: Unique MRSA's Multiple Virulence Factors, Genome, and Stepwise Evolution

    PubMed Central

    Khokhlova, Olga E.; Hung, Wei-Chun; Wan, Tsai-Wen; Iwao, Yasuhisa; Takano, Tomomi; Higuchi, Wataru; Yachenko, Svetlana V.; Teplyakova, Olga V.; Kamshilova, Vera V.; Kotlovsky, Yuri V.; Nishiyama, Akihito; Reva, Ivan V.; Sidorenko, Sergey V.; Peryanova, Olga V.; Reva, Galina V.; Teng, Lee-Jene; Salmina, Alla B.; Yamamoto, Tatsuo

    2015-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a common multidrug-resistant (MDR) pathogen. We herein discussed MRSA and its infections in Krasnoyarsk, Siberian Russia between 2007 and 2011. The incidence of MRSA in 3,662 subjects was 22.0% and 2.9% for healthcare- and community-associated MRSA (HA- and CA-MRSA), respectively. The 15-day mortality rates for MRSA hospital- and community-acquired pneumonia (HAP and CAP) were 6.5% and 50%, respectively. MRSA CAP cases included pediatric deaths; of the MRSA pneumonia episodes available, ≥27.3% were associated with bacteremia. Most cases of HA-MRSA examined exhibited ST239/spa3(t037)/SCCmecIII.1.1.2 (designated as ST239Kras), while all CA-MRSA cases examined were ST8/spa1(t008)/SCCmecIV.3.1.1(IVc) (designated as ST8Kras). ST239Kras and ST8Kras strongly expressed cytolytic peptide (phenol-soluble modulin α, PSMα; and δ-hemolysin, Hld) genes, similar to CA-MRSA. ST239Kras pneumonia may have been attributed to a unique set of multiple virulence factors (MVFs): toxic shock syndrome toxin-1 (TSST-1), elevated PSMα/Hld expression, α-hemolysin, the staphylococcal enterotoxin SEK/SEQ, the immune evasion factor SCIN/SAK, and collagen adhesin. Regarding ST8Kras, SEA was included in MVFs, some of which were common to ST239Kras. The ST239Kras (strain OC3) genome contained: a completely unique phage, φSa7-like (W), with no att repetition; S. aureus pathogenicity island SaPI2R, the first TSST-1 gene-positive (tst+) SaPI in the ST239 lineage; and a super copy of IS256 (≥22 copies/genome). ST239Kras carried the Brazilian SCCmecIII.1.1.2 and United Kingdom-type tst. ST239Kras and ST8Kras were MDR, with the same levofloxacin resistance mutations; small, but transmissible chloramphenicol resistance plasmids spread widely enough to not be ignored. These results suggest that novel MDR and MVF+ HA- and CA-MRSA (ST239Kras and ST8Kras) emerged in Siberian Russia (Krasnoyarsk) associated with fatal pneumonia, and also with ST

  1. Methicillin-resistant Staphylococcus aureus (MRSA) is associated with low within-herd prevalence of intra-mammary infections in dairy cows: Genotyping of isolates.

    PubMed

    Luini, M; Cremonesi, P; Magro, G; Bianchini, V; Minozzi, G; Castiglioni, B; Piccinini, R

    2015-08-01

    Staphylococcus aureus is one of the most common mastitis-causing pathogens worldwide. In the last decade, livestock-associated methicillin-resistant S. aureus (LA-MRSA) infections have been described in several species, included the bovines. Hence, this paper investigates the diffusion of MRSA within Italian dairy herds; the strains were further characterized using a DNA microarray, which detects 330 different sequences, including the methicillin-resistance genes mecA and mecC and SCCmec typing. The analysis of overall patterns allows the assignment to Clonal Complexes (CC). Overall 163 S. aureus isolates, collected from quarter milk samples in 61 herds, were tested. MRSA strains were further processed using spa typing. Fifteen strains (9.2%), isolated in 9 herds (14.75%), carried mecA, but none harboured mecC. MRSA detection was significantly associated (P<0.011) with a within-herd prevalence of S. aureus intra-mammary infections (IMI) ≤5%. Ten MRSA strains were assigned to CC398, the remaining ones to CC97 (n=2), CC1 (n=2) or CC8 (n=1). In 3 herds, MRSA and MSSA co-existed: CC97-MRSA with CC398-MSSA, CC1-MRSA with CC8-MSSA and CC398-MRSA with CC126-MSSA. The results of spa typing showed an overall similar profile of the strains belonging to the same CC: t127-CC1, t1730-CC97, t899 in 8 out of 10 CC398. In the remaining 2 isolates a new spa type, t14644, was identified. The single CC8 was a t3092. The SCCmec cassettes were classified as type IV, type V or type IV/V composite. All or most strains harboured the genes encoding the β-lactamase operon and the tetracycline resistance. Streptogramin resistance gene was related to CC398. Enterotoxin and leukocidin genes were carried only by CC1, CC8 and CC97-MRSA. The persistence of MRSA clones characterized by broader host range, in epidemiologically unrelated areas and in dairy herds with low prevalence of S. aureus IMI, might enhance the risk for adaptation to human species.

  2. Avenaciolides: potential MurA-targeted inhibitors against peptidoglycan biosynthesis in methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Chang, Ching-Ming; Chern, Jeffy; Chen, Ming-Yi; Huang, Kai-Fa; Chen, Chein-Hung; Yang, Yu-Liang; Wu, Shih-Hsiung

    2015-01-14

    Discovery of new antibiotics for combating methicillin-resistant Staphylococcus aureus (MRSA) is of vital importance in the post-antibiotic era. Here, we report four avenaciolide derivatives (1-4) isolated from Neosartorya fischeri, three of which had significant antimicrobial activity against MRSA. The morphology of avenaciolide-treated cells was protoplast-like, which indicated that cell wall biosynthesis was interrupted. Comparing the structures and minimum inhibitory concentrations of 1-4, the α,β-unsaturated carbonyl group seems to be an indispensable moiety for antimicrobial activity. Based on a structural similarity survey of other inhibitors with the same moiety, we revealed that MurA was the drug target. This conclusion was validated by (31)P NMR spectroscopy and MS/MS analysis. Although fosfomycin, which is the only clinically used MurA-targeted antibiotic, is ineffective for treating bacteria harboring the catalytically important Cys-to-Asp mutation, avenaciolides 1 and 2 inhibited not only wild-type but also fosfomycin-resistant MurA in an unprecedented way. Molecular simulation revealed that 2 competitively perturbs the formation of the tetrahedral intermediate in MurA. Our findings demonstrated that 2 is a potent inhibitor of MRSA and fosfomycin-resistant MurA, laying the foundation for the development of new scaffolds for MurA-targeted antibiotics.

  3. Immunization protected well nourished mice but not undernourished ones from lung injury in Methicillin-resistant Staphylococcus aureus (MRSA) infection

    PubMed Central

    2009-01-01

    Background Staphylococcus aureus methicillin-resistant (MRSA) has been frequently isolated from endotracheal and lung puncture aspirates in malnourished children with pneumonia. In this work we evaluated the susceptibility of undernourished BALB/c mice and its ability to mount a protective immunity against MRSA with emphasis on the lung involvement. Results BALB/c mice submitted to a 20% dietary restriction during 20 days presented a significant decrease in body weight, lymphocyte number and also atrophy in thymus and intestinal epithelium. Determination of bacterial load by the number of colony forming units (CFU) indicated a similar susceptibility whereas the findings of Gram stain clearly suggested a higher amount of bacteria in the lungs of normal mice than in the undernourished ones. Immunization reduced bacterial growth in the lungs of normal mice but not in the undernourished ones. Histopathological analysis showed that inflammation appeared in the lungs from normal mice only after infection and that immunization prevented this pulmonary inflammatory process. On the other hand, undernourished mice presented lung inflammation even before infection. In addition, the degree of this inflammatory process did not change with infection or previous immunization. Conclusion Our results indicated that lung injury during MRSA infection is prevented by previous immunization in well nourished but not in undernourished mice. PMID:19930660

  4. Prospective Comparison of the Clinical Impacts of Heterogeneous Vancomycin-Intermediate Methicillin-Resistant Staphylococcus aureus (MRSA) and Vancomycin-Susceptible MRSA▿ †

    PubMed Central

    Horne, K. C.; Howden, B. P.; Grabsch, E. A.; Graham, M.; Ward, P. B.; Xie, S.; Mayall, B. C.; Johnson, P. D. R.; Grayson, M. L.

    2009-01-01

    Although methicillin (meticillin)-resistant Staphylococcus aureus (MRSA) strains with reduced susceptibility to vancomycin (RVS-MRSA; including vancomycin-intermediate S. aureus [VISA] and heterogeneous VISA [hVISA]) have been linked with vancomycin treatment failure, it is unclear whether they are more pathogenic than vancomycin-susceptible MRSA (VS-MRSA). We prospectively assessed patients with clinical MRSA isolates during a 10-month period to determine clinical status (infection versus colonization) and therapeutic outcome before correlating these findings with the results of detailed in vitro assessment of vancomycin susceptibility, including population analysis profile (PAP) testing. hVISA and VISA were defined by standard PAP criteria (area-under-the-curve ratio compared to that of the reference hVISA strain Mu3 [≥0.9]) and routine CLSI criteria (vancomycin MIC, 4 to 8 μg/ml), respectively. Among the 117 patients assessed, 58 had RVS-MRSA isolates (56 hVISA and 2 VISA) and 59 had VS-MRSA isolates; the patient demographics and comorbidities were similar. RVS-MRSA was associated with a lower rate of infection than VS-MRSA (29/58 versus 46/59; P = 0.003), including a lower rate of bacteremia (3/58 versus 20/59, respectively; P < 0.001). The cure rates in RVS-MRSA and VS-MRSA groups were not statistically different (16/26 versus 31/42; P = 0.43), but the post hoc assessment of treatment regimes and study size made detailed conclusions difficult. The results of the macro method Etest correlated well with the PAP results (sensitivity, 98.3%, and specificity, 91.5%), but broth microdilution and our preliminary RVS-MRSA detection method correlated poorly. All isolates were susceptible to linezolid and daptomycin. These data suggest that detailed prospective laboratory identification of RVS-MRSA isolates may be of limited value and that, instead, such in vitro investigation should be reserved for isolates from patients who are failing appropriate anti-MRSA therapy

  5. Synthesis and antibacterial evaluation of a novel series of synthetic phenylthiazole compounds against methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Mohammad, Haroon; Reddy, P V Narasimha; Monteleone, Dennis; Mayhoub, Abdelrahman S; Cushman, Mark; Seleem, Mohamed N

    2015-04-13

    Methicillin-resistant Staphylococcus aureus infections are a significant global health challenge in part due to the emergence of strains exhibiting resistance to nearly all classes of antibiotics. This underscores the urgent need for the rapid development of novel antimicrobials to circumvent this burgeoning problem. Previously, whole-cell screening of a library of 2,5-disubstituted thiazole compounds revealed a lead compound exhibiting potent antimicrobial activity against MRSA. The present study, conducting a more rigorous analysis of the structure-activity relationship of this compound, reveals a nonpolar, hydrophobic functional group is favored at thiazole-C2 and an ethylidenehydrazine-1-carboximidamide moiety is necessary at C5 for the compound to possess activity against MRSA. Furthermore, the MTS assay confirmed analogs 5, 22d, and 25 exhibited an improved toxicity profile (not toxic up to 40 μg/mL to mammalian cells) over the lead 1. Analysis with human liver microsomes revealed compound 5 was more metabolically stable compared to the lead compound (greater than eight-fold improvement in the half-life in human liver microsomes). Collectively the results presented demonstrate the novel thiazole derivatives synthesized warrant further exploration for potential use as future antimicrobial agents for the treatment of multidrug-resistant S. aureus infections.

  6. Synthesis and antibacterial evaluation of a novel series of synthetic phenylthiazole compounds against methicillin-resistant Staphylococcus aureus (MRSA)

    PubMed Central

    Mohammad, Haroon; Narasimha Reddy, P. V.; Monteleone, Dennis; Mayhoub, Abdelrahman S.; Cushman, Mark; Seleem, Mohamed N.

    2015-01-01

    Methicillin-resistant Staphylococcus aureus infections are a significant global health challenge in part due to the emergence of strains exhibiting resistance to nearly all classes of antibiotics. This underscores the urgent need for the rapid development of novel antimicrobials to circumvent this burgeoning problem. Previously, whole-cell screening of a library of 2,5-disubstituted thiazole compounds revealed a lead compound exhibiting potent antimicrobial activity against MRSA. The present study, conducting a more rigorous analysis of the structure-activity relationship of this compound, reveals a nonpolar, hydrophobic functional group is favored at thiazole-C2 and an ethylidenehydrazine-1-carboximidamide moiety is necessary at C5 for the compound to possess activity against MRSA. Furthermore, the MTS assay confirmed analogues 5, 22d, and 25 exhibited an improved toxicity profile (not toxic up to 40 μg/mL to mammalian cells) over the lead 1. Analysis with human liver microsomes revealed compound 5 was more metabolically stable compared to the lead compound (greater than eight-fold improvement in the half-life in human liver microsomes). Collectively the results presented demonstrate the novel thiazole derivatives synthesized warrant further exploration for potential use as future antimicrobial agents for the treatment of multidrug-resistant S. aureus infections. PMID:25771109

  7. Dynamics of Biofilm Formation and the Interaction between Candida albicans and Methicillin-Susceptible (MSSA) and -Resistant Staphylococcus aureus (MRSA)

    PubMed Central

    Zago, Chaiene Evelin; Silva, Sónia; Sanitá, Paula Volpato; Barbugli, Paula Aboud; Dias, Carla Maria Improta; Lordello, Virgínia Barreto; Vergani, Carlos Eduardo

    2015-01-01

    Polymicrobial biofilms are an understudied and a clinically relevant problem. This study evaluates the interaction between C. albicans, and methicillin- susceptible (MSSA) and resistant (MRSA) S. aureus growing in single- and dual-species biofilms. Single and dual species adhesion (90 min) and biofilms (12, 24, and 48 h) were evaluated by complementary methods: counting colony-forming units (CFU mL-1), XTT-reduction, and crystal violet staining (CV). The secretion of hydrolytic enzymes by the 48 h biofilms was also evaluated using fluorimetric kits. Scanning electron microscopy (SEM) was used to assess biofilm structure. The results from quantification assays were compared using two-way ANOVAs with Tukey post-hoc tests, while data from enzymatic activities were analyzed by one-way Welch-ANOVA followed by Games-Howell post hoc test (α = 0.05). C. albicans, MSSA and MRSA were able to adhere and to form biofilm in both single or mixed cultures. In general, all microorganisms in both growth conditions showed a gradual increase in the number of cells and metabolic activity over time, reaching peak values between 12 h and 48 h (ρ<0.05). C. albicans single- and dual-biofilms had significantly higher total biomass values (ρ<0.05) than single biofilms of bacteria. Except for single MRSA biofilms, all microorganisms in both growth conditions secreted proteinase and phospholipase-C. SEM images revealed extensive adherence of bacteria to hyphal elements of C. albicans. C. albicans, MSSA, and MRSA can co-exist in biofilms without antagonism and in an apparent synergistic effect, with bacteria cells preferentially associated to C. albicans hyphal forms. PMID:25875834

  8. Epidemiology of methicillin-resistant and -susceptible Staphylococcus aureus in Luanda, Angola: first description of the spread of the MRSA ST5-IVa clone in the African continent.

    PubMed

    Conceição, Teresa; Coelho, Céline; Santos-Silva, Isabel; de Lencastre, Hermínia; Aires-de-Sousa, Marta

    2014-10-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a major human pathogen worldwide, and although surveillance studies are available in the most developed countries, data from Angola are inexistent. In June 2012, 295 inpatients and 199 healthcare workers from three hospitals in Luanda, Angola were nasal swabbed for S. aureus and MRSA carriage. A total of 117 individuals (23.7%) were S. aureus nasal carriers, out of which 68 (58.1%) were colonized with MRSA. The majority of the MRSA isolates (74%) belonged to a single clonal lineage, pulsed-field gel electrophoresis (PFGE) A-ST5-IVa associated with three spa types (spa types t105/t311/t11657), followed by PFGE C-ST88-IVa (spa types t186/t325/t786/t1951/t3869) (n=9; 12%); the other 11 MRSA isolates were representatives of 4 additional lineages. Almost half (49%) of the methicillin-susceptible S. aureus (MSSA) isolates belonged to three major clones: PFGE B-ST508 (spa types t050/t861/t1346/t1574/t2626/t12218), PFGE D-ST45 (spa types t939/t11656), and PFGE E-ST30 (spa types t1202/t9118). MSSA isolates presented a high variability of virulence factors, including Panton-Valentine leukocidine (7.9%). MRSA carriage in Luanda is considerably high, and the major clone corresponds to a worldwide epidemic lineage, so far scarcely reported in Africa. Additional infection control measures in this metropolis are mandatory for a global MRSA control.

  9. Determining the prevalence of SCCmec polymorphism, virulence and antibiotic resistance genes among methicillin-resistant Staphylococcus aureus (MRSA) isolates collected from selected hospitals in west of Iran.

    PubMed

    Taherikalani, Morovat; Mohammadzad, Mohammad Reza; Soroush, Setareh; Maleki, Mohammad Hossein; Azizi-Jalilian, Farid; Pakzad, Iraj; Sadeghifard, Nourkhoda; Asadollahi, Parisa; Emaneini, Mohammad; Monjezi, Aazam; Alikhani, Mohammad Yousef

    2016-04-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most important pathogens worldwide and compared to other staphylococcal species that are associated with higher mortality rate. A total of 500 Staphylococcus spp. was collected from selected hospitals in Ilam, Kermanshah, Khorram Abad and Hamadan cities and, via phenotypic and genotypic methods, was assessed to find MRSA. The presence or absence of prevalent antibiotic resistance genes and virulence genes was evaluated among MRSA isolates, using polymerase chain reaction (PCR) method, and then the SCCmec typing of these isolates was assayed by multiplex PCR. A total of 372 (74.4%) Stapylococcus spp. isolates were identified as S. aureus, among which 200 (53.8%) possessed the mecA gene and were distinguished as MRSA. All of MRSA isolates contained blaZ gene. The frequency of ermA and ermC genes among erythromycin-resistant MRSA isolates was 21.6% and 66.7%, respectively. The frequency of the virulence genes eta, hla and sea among MRSA isolates was 10%, 80.5% and 100%, respectively. SCCmec type IV accounted for 30.6% of the MRSA isolates and SCCmec type III, SCCmec type II and SCCmec type I accounted for 30%, 22% and 17.5% of the isolates, respectively. The antibiotic resistance genes and the virulence genes of blaZ, hla, sea, eta and ermC had high frequencies among the MRSA isolates. This study showed that the antibiotic resistance genes had higher frequencies among SCCmec types I and IV, which confirms the previous reports in this field.

  10. Stopping MRSA

    ERIC Educational Resources Information Center

    Vogel, Carl

    2008-01-01

    Last fall, a fever gripped the nation--an overheating of news stories about the so-called super bug: methicillin-resistant Staphylococcus aureus, "staph," or simply "MRSA." The bacteria are not airborne contaminants, but when they enter a person's body through cuts, abrasions, or other breaks in the skin, they can cause infections, which can…

  11. [Guidelines for prevention, control and treatment of infections caused by methicillin-resistant Staphylococcus aureus (MRSA): changes and updates of chapter 7.0: treatment of patients with MRSA infection].

    PubMed

    Kalenić, Smilja; Pal, Marina Payerl; Palcevski, Vera Vlahović; Horvatić, Jasminka; Mestrović, Tomislav; Barsić, Bruno; Stamenić, Valerija; Burcar, Ivan; Korusić, Andelko; Vucić, Marinko; Civljak, Rok; Stancić, Marin; Budimir, Ana

    2010-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is an important pathogen throughout the world, and as well in Croatia. Therefore it was decided to develop guidelines with the aim to reduce the number of patients infected/colonized with MRSA in healthcare facilities and in nursing homes in Croatia, consequently reducing MRSA-related morbidity and mortality. An interdisciplinary team of experts developed these guidelines using existing international guidelines from different countries, and literature reviews about prevention, control, treatment and laboratory diagnosis of MRSA infections. Grades of evidence for specific recommendations were determined using CDC/HICPAC grading system. Categorization is based on existing data, theoretical basis, applicability and economic impact. After a broad discussion in different professional societies, Guidelines were accepted. In the meantime, several new possibilities appeared in the treatment of patients with MRSA infections in Croatia, so the Chapter 7.0 Treatment of patients with MRSA infections is changed and updated according to the new treatment possibilities. The rest of the Guidelines was not changed. PMID:21294322

  12. MRSA in Schools

    ERIC Educational Resources Information Center

    US Department of Education, 2007

    2007-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a form of Staphylococcus aureus, a common bacterium that has developed resistance to several forms of antibiotics. MRSA has been around for many years, mostly in health care settings but has moved into the community in recent years. Infections can be seen anywhere but are mostly seen in…

  13. Differences in Epidemiological and Molecular Characteristics of Nasal Colonization with Staphylococcus aureus (MSSA-MRSA) in Children from a University Hospital and Day Care Centers

    PubMed Central

    Rodríguez, Erika A.; Correa, Margarita M.; Ospina, Sigifredo; Atehortúa, Santiago L.; Jiménez, J. Natalia

    2014-01-01

    Background Clinical significance of Staphylococcus aureus colonization has been demonstrated in hospital settings; however, studies in the community have shown contrasting results regarding the relevance of colonization in infection by community-associated MRSA (CA-MRSA). In Colombia there are few studies on S. aureus colonization. The aim of this study was to determine the molecular and epidemiological characteristics of nasal colonization by S. aureus (MSSA-MRSA) in children from a university hospital and day care centers (DCCs) of Medellin, Colombia. Methods An observational cross-sectional study was conducted in 400 children (200 in each setting), aged 0 months to 5 years, during 2011. Samples were collected from each nostril and epidemiological information was obtained from the parents. Genotypic analysis included spa typing, PFGE, MLST, SCCmec typing, detection of genes for virulence factors and agr groups. Results Frequency of S. aureus colonization was 39.8% (n = 159) (hospital 44.5% and DCCs 35.0%) and by MRSA, 5.3% (n = 21) (hospital 7.0% and DCCs 3.5%). Most S. aureus colonized children were older than two years (p = 0.005), the majority of them boys (59.1%), shared a bedroom with a large number of people (p = 0.028), with history of β-Lactamase inhibitors usage (p = 0.020). MSSA strains presented the greatest genotypic diversity with 15 clonal complexes (CC). MRSA isolates presented 6 CC, most of them (47.6%) belonged to CC8-SCCmec IVc and were genetically related to previously reported infectious MRSA strains. Conclusion Differences in epidemiological and molecular characteristics between populations may be useful for the understanding of S. aureus nasal colonization dynamics and for the design of strategies to prevent S. aureus infection and dissemination. The finding of colonizing MRSA with similar molecular characteristics of those causing infection demonstrates the dissemination capacity of S. aureus and the risk of infection

  14. Massive dissemination of methicillin resistant Staphylococcus aureus in bloodstream infections in a high MRSA prevalence country: establishment and diversification of EMRSA-15.

    PubMed

    Faria, Nuno A; Miragaia, Maria; de Lencastre, Hermínia

    2013-12-01

    Portugal is the European country with the highest prevalence of methicillin resistant Staphylococcus aureus (MRSA), in which EMRSA-15 (ST22-IVh) has been the dominant clone since soon after its introduction in Portuguese hospitals in 2001. In this study, we intend to not only, assess the evolution of the invasive MRSA in Portuguese hospitals, but also to evaluate the invasive methicillin susceptible S. aureus (MSSA) population and the relationship between both populations. In the current study, two major MRSA clones were identified: EMRSA-15 that has been dominant for more than 10 years and accounts for 75% of the MRSA isolates, and ST105-II, a clone related with the New York/Japan clone (ST5-II). In contrast, among MSSA, several clonal backgrounds were identified. Despite of the massive predominance of EMRSA-15 in the last decade, an increase in spa diversity has been observed in the last few years, which suggests a recent and local diversification of this clone. Interestingly, MRSA and MSSA populations with related clonal backgrounds appear to have increased as a result of the dissemination of MRSA to the community environment.

  15. Molecular Epidemiology of Methicillin-Resistant Staphylococcus aureus (MRSA) among Patients Admitted to Adult Intensive Care Units: the STAR*ICU Trial

    PubMed Central

    Nair, Nisha; Kourbatova, Ekaterina; Poole, Katharine; Huckabee, Charmaine M.; Murray, Patrick; Huskins, W. Charles; Blumberg, Henry M.

    2014-01-01

    Background The multi-center cluster-randomized Strategies to Reduce Transmission of Antimicrobial Resistant Bacteria in Intensive Care Units (STAR*ICU) trial was carried out in 18 U.S. adult intensive care units (ICUs) and evaluated the effectiveness of infection control strategies in reducing transmission of methicillin-resistant Staphylococcus aureus (MRSA) colonization and/or infection. Our study objective was to examine the molecular epidemiology of MRSA and assess the prevalence and risk factors for community acquired (CA)-MRSA genotype nasal carriage at the time of ICU admission. Methods Selected MRSA isolates were subjected to molecular typing using pulsed-field gel electrophoresis. Results Among 5,512 ICU patient-admissions in the STAR*ICU trial during the intervention period, 626 (11%) had a positive nares culture for MRSA. 210/626 (34%) available isolates were selected by weighted random sampling for molecular typing. Of 210 patients, 123 (59%) were male; mean age was 63 years. Molecular typing revealed that 147 isolates (70%) were the USA100 clone; 26 (12%) USA300; 12 (6%) USA500; 8 (4%) USA800; 17 (8%) other. In multivariate analysis, patients with CA-MRSA genotype (USA300, USA400, or USA1000) colonization were less likely to have been hospitalized during the previous 12 months (PR=0.39; 95% C.I. 0.21–0.73) and less likely to have an older age (PR=0.97 per year; 0.95–0.98) compared to patients with a HA-MRSA genotype. Conclusion CA-MRSA genotypes have emerged as a cause of MRSA nares colonization among patients admitted to adult ICUs in the U.S. During the study period (2006), the predominant site of CA-MRSA genotype acquisition appeared to be in the community. PMID:22011531

  16. A retrospective study of risk factors for poor outcomes in methicillin-resistant staphylococcus aureus (MRSA) infection in surgical patients

    PubMed Central

    2011-01-01

    Background Since its isolation, Methicillin-resistant Staphlococcus aureus (MRSA) has become a major cause of hospital acquired infection (HAI), adverse patient outcome and overall resource utilisation. It is endemic in Scotland and widespread in Western hospitals. MRSA has been the subject of widespread media interest- a manifestation of concerns about sterile surgical techniques and hospital cleanliness. This study aimed to investigate patient outcome of MRSA infections over the last decade at a major orthopaedic trauma centre. The objective was to establish the association of variables, such as patient age and inpatient residence, against patient outcome, in order to quantify significant relationships; facilitating the evaluation of management strategies with an aim to improving patient outcomes and targeting high-risk procedures. Methods This is a retrospective study of the rates and outcomes of MRSA infection in orthopaedic trauma at the Royal Infirmary of Edinburgh. Data was collated using SPSS 14.0 for Windows(R). Shapiro-Wilkes testing was performed to investigate the normality of continuous data sets (e.g: age). Data was analysed using both Chi-Squared and Fisher's exact tests (in cases of expected values under 5) Results This study found significant associations between adverse patient outcome (persistent deep infection, osteomyelitis, the necessity for revision surgery, amputation and mortality) and the following patient variables: Length of inpatient stay, immuno-compromise, pre-admission residence in an institutional setting (such as a residential nursing home) and the number of antibiotics used in patient care. Despite 63% of all infections sampled resulting from proximal femoral fractures, no association between patient outcome and site of infection or diagnosis was found. Somewhat surprisingly, the relationship between age and outcome of infection was not proved to be significant, contradicting previous studies suggesting a statistical association

  17. A 5-year survey of antimicrobial susceptibility profiles of methicillin-resistant Staphylococcus aureus (MRSA) isolated from patients with bloodstream infections in Northeast Italy.

    PubMed

    Cojutti, Piergiorgio; Scarparo, Claudio; Sartor, Assunta; Coato, Paola; Rigoli, Roberto; Pea, Federico

    2015-01-01

    A 5-year survey (2009-2013) of antimicrobial susceptibility of methicillin-resistant Staphylococcus aureus (MRSA) isolated from patients with bloodstream infections was carried out in Northeast Italy. No upward creep of glycopeptides MICs was documented among 582 nonduplicate MRSA blood isolates, which were tested in accordance with broth microdilution and interpreted in accordance with EUCAST recommendations. Teicoplanin showed stably a lower MIC50 in comparison with vancomycin (0.25-0.5 versus 1 mg/L). The activities of newer anti-MRSA antibacterials stratified by glycopeptides MICs showed similar trends in MICs of either vancomycin or teicoplanin with those of daptomycin, linezolid, and tigecycline. We hypothesize that in centers with different distribution of glycopeptides MICs, downward for teicoplanin and upward for vancomycin, teicoplanin could be a more effective alternative to vancomycin for empirical treatment of MRSA-related bacteremia.

  18. Anatomical patterns of colonization of pets with staphylococcal species in homes of people with methicillin-resistant Staphylococcus aureus (MRSA) skin or soft tissue infection (SSTI).

    PubMed

    Iverson, S A; Brazil, A M; Ferguson, J M; Nelson, K; Lautenbach, E; Rankin, S C; Morris, D O; Davis, M F

    2015-03-23

    Methicillin-resistant strains of Staphylococcus aureus (MRSA), Staphylococcus pseudintermedius (MRSP), and other pathogenic staphylococci can cause infections in companion animals and humans. Identification of colonized animals is fundamental to research and practice needs, but harmonized methods have not yet been established. To establish the optimal anatomic site for the recovery of methicillin-resistant coagulase positive staphylococci (CPS), survey data and swabs were collected from 196 pets (dogs, cats, reptiles, birds, fish and pocket pets) that lived in households with an MRSA-infected person. Using broth-enrichment culture and PCR for speciation, S. aureus was identified in 27 of 179 (15%) pets sampled at baseline and 19 of 125 (15%) pets sampled at a three-month follow-up home visit. S. pseudintermedius was isolated from 33 of 179 (18%) pets sampled at baseline and 21 of 125 (17%) of pets sampled at follow-up. The baseline MRSA and MRSP prevalence was 8% and 1% respectively from 145 mammalian pets. The follow-up MRSA and MRSP prevalence was 7% and <1% respectively from 95 mammalian pets. The mouth was the most sensitive single site sampled for isolation of S. aureus and S. pseudintermedius in mammals. In a subset of pets, from which all available isolates were identified, dual carriage of S. aureus and S. pseudintermedius was 22% at baseline and 11% at follow-up. These results identify the mouth as the most sensitive site to screen for pathogenic staphylococci and suggest that it should be included in sampling protocols.

  19. Population-Based Estimates of Methicillin-Resistant "Staphylococcus aureus" (MRSA) Infections among High School Athletes--Nebraska, 2006-2008

    ERIC Educational Resources Information Center

    Buss, Bryan F.; Mueller, Shawn W.; Theis, Max; Keyser, Alison; Safranek, Thomas J.

    2009-01-01

    Methicillin-resistant "Staphylococcus aureus" (MRSA) is an emerging cause of skin and soft-tissue infections among athletes. To determine statewide incidence among high school athletes, we surveyed all 312 Nebraska high schools regarding sport programs offered, program-specific participation numbers, number of athletes with physician-diagnosed…

  20. Evaluation of a New Selective Medium, BD BBL CHROMagar MRSA II, for Detection of Methicillin-Resistant Staphylococcus aureus in Different Specimens▿

    PubMed Central

    Wendt, C.; Havill, N. L.; Chapin, K. C.; Boyce, J. M.; Dickenson, R.; Eigner, U.; Schütt, S.; Fahr, A. M.

    2010-01-01

    The sensitivity of screening for methicillin-resistant Staphylococcus aureus (MRSA) can be improved by adding other specimen sites to nares. We describe an evaluation of a new selective medium, BBL CHROMagar MRSA II (CMRSAII), for its ability to detect MRSA from different specimen types. CMRSAII is a chromogenic medium which incorporates cefoxitin for the detection of MRSA. A study was performed at four clinical laboratories with the following specimens: 1,446 respiratory, 694 stool, 1,275 skin, and 948 wound specimens and 688 blood culture bottles containing Gram-positive cocci. The recovery of MRSA on traditional culture media was compared to results with CMRSAII. S. aureus was tested by cefoxitin disk diffusion. CMRSAII was interpreted as positive for MRSA at 24 h (range, 18 to 28 h) based solely on the visualization of mauve-colored colonies and at 48 h (range, 36 to 52 h) based on detection of mauve colonies with subsequent confirmation as S. aureus (by coagulase or latex agglutination testing). MRSA was recovered more frequently on CMRSAII (89.8% at 24 h and 95.6% at 48 h) than on traditional culture plates (83.1% at 24 h and 79.8% at 48 h) for all specimen types combined (P < 0.001). The percent sensitivities of CMRSAII at 24- and 48-h reads, respectively, were 85.5 and 92.4% for respiratory specimens, 87.9% and 98.3% for stool specimens, 88.4% and 96.1% for skin specimens, 92.1% and 94.6% for wound specimens, and 100% and 100% for positive blood cultures. The specificity was 99.8% for respiratory specimens and 100% for all others. In conclusion, CMRSAII is a reliable screening medium for multiple specimen types. PMID:20392927

  1. Antibacterial Evaluation of Synthetic Thiazole Compounds In Vitro and In Vivo in a Methicillin-Resistant Staphylococcus aureus (MRSA) Skin Infection Mouse Model.

    PubMed

    Mohammad, Haroon; Cushman, Mark; Seleem, Mohamed N

    2015-01-01

    The emergence of community-associated methicillin-resistant Staphylococcus aureus (MRSA), including strains resistant to current antibiotics, has contributed to an increase in the number of skin infections reported in humans in recent years. New therapeutic options are needed to counter this public health challenge. The aim of the present study was to examine the potential of thiazole compounds synthesized by our research group to be used topically to treat MRSA skin and wound infections. The broth microdilution method confirmed that the lead thiazole compound and four analogues are capable of inhibiting MRSA growth at concentrations as low as 1.3 μg/mL. Additionally, three compounds exhibited a synergistic relationship when combined with the topical antibiotic mupirocin against MRSA in vitro via the checkerboard assay. Thus the thiazole compounds have potential to be used alone or in combination with mupirocin against MRSA. When tested against human keratinocytes, four derivatives of the lead compound demonstrated an improved toxicity profile (were found to be non-toxic up to a concentration of 20 μg/mL). Utilizing a murine skin infection model, we confirmed that the lead compound and three analogues exhibited potent antimicrobial activity in vivo, with similar capability as the antibiotic mupirocin, as they reduced the burden of MRSA present in skin wounds by more than 90%. Taken altogether, the present study provides important evidence that these thiazole compounds warrant further investigation for development as novel topical antimicrobials to treat MRSA skin infections.

  2. Artesunate has its enhancement on antibacterial activity of β-lactams via increasing the antibiotic accumulation within methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Jiang, Weiwei; Li, Bin; Zheng, Xinchuan; Liu, Xin; Pan, Xichun; Qing, Rongxin; Cen, Yanyan; Zheng, Jiang; Zhou, Hong

    2013-06-01

    Methicillin-resistant Staphylococcus aureus (MRSA) has now emerged as a predominant and serious pathogen because of its resistance to a large group of antibiotics, leading to high morbidity and mortality. Therefore, to develop new agents against resistance is urgently required. Previously, artesunate (AS) was found to enhance the antibacterial effect of β-lactams against MRSA. In this study, AS was first found to increase the accumulation of antibiotics (daunorubicin and oxacillin) within MRSA by laser confocal microscopy and liquid chromatography-tandem MS method, suggesting the increased antibiotics accumulation might be related to the enhancement of AS on antibiotics. Furthermore, AS was found not to destroy the cell structure of MRSA by transmission electron microscope. AS was found to inhibit gene expressions of important efflux pumps such as NorA, NorB and NorC, but not MepA, SepA and MdeA. In conclusion, our results showed that AS was capable of enhancing the antibacterial activity of β-lactams via increasing antibiotic accumulations within MRSA through inhibiting gene expressions of efflux pumps such as NorA, NorB and NorC, but did not destroy the cell structure of MRSA. AS could be further investigated as a candidate drug for treatment of MRSA infection.

  3. The first report in Brazil of severe infection caused by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA).

    PubMed

    Rozenbaum, R; Sampaio, M G; Batista, G S; Garibaldi, A M; Terra, G M F; Souza, M J; Vieira, E N; Silva-Carvalho, M C; Teixeira, L A; Figueiredo, A M S

    2009-08-01

    Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) is an emergent pathogen in Brazil. However, there are no data on the prevalence of CA-MRSA. We report here the first well-characterized case of severe life-threatening CA-MRSA infection in a child living in Rio de Janeiro city. The patient had many complications including hematogenous osteomyelitis and involvement of multiple sites requiring drainage of soft-tissue abscess, and pleural and pericardial empyema. The MRSA isolates recovered were genotyped using PFGE, SCCmec typing and multilocus sequence typing. Disk diffusion tests were performed following Clinical and Laboratory Standards Institute recommendations. In addition, the presence of Panton-Valentine leukocidin (PVL) was assessed by PCR amplification, using specific primers for lukF-pv (encoding for the F subunit of the PVL). The bacterial isolates were related to the ST30-SCCmecIV lineage (Oceania Southwest Pacific clone), a PVL producer CA-MRSA previously detected in Porto Alegre, RS, Brazil. Also, the isolates analyzed were susceptible to all non-beta-lactam antibiotics tested. The present report demonstrates that disseminated CA-MRSA disease is also occurring in Rio de Janeiro. Thus, the empirical treatment of moderate or severe infections suspected of being associated with CA-MRSA needs to be reviewed in order to allow prompt initiation of an effective therapy that also covers these microorganisms.

  4. Antibacterial Evaluation of Synthetic Thiazole Compounds In Vitro and In Vivo in a Methicillin-Resistant Staphylococcus aureus (MRSA) Skin Infection Mouse Model

    PubMed Central

    Mohammad, Haroon; Cushman, Mark; Seleem, Mohamed N.

    2015-01-01

    The emergence of community-associated methicillin-resistant Staphylococcus aureus (MRSA), including strains resistant to current antibiotics, has contributed to an increase in the number of skin infections reported in humans in recent years. New therapeutic options are needed to counter this public health challenge. The aim of the present study was to examine the potential of thiazole compounds synthesized by our research group to be used topically to treat MRSA skin and wound infections. The broth microdilution method confirmed that the lead thiazole compound and four analogues are capable of inhibiting MRSA growth at concentrations as low as 1.3 μg/mL. Additionally, three compounds exhibited a synergistic relationship when combined with the topical antibiotic mupirocin against MRSA in vitro via the checkerboard assay. Thus the thiazole compounds have potential to be used alone or in combination with mupirocin against MRSA. When tested against human keratinocytes, four derivatives of the lead compound demonstrated an improved toxicity profile (were found to be non-toxic up to a concentration of 20 μg/mL). Utilizing a murine skin infection model, we confirmed that the lead compound and three analogues exhibited potent antimicrobial activity in vivo, with similar capability as the antibiotic mupirocin, as they reduced the burden of MRSA present in skin wounds by more than 90%. Taken altogether, the present study provides important evidence that these thiazole compounds warrant further investigation for development as novel topical antimicrobials to treat MRSA skin infections. PMID:26536129

  5. Nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) among Swiss veterinary health care providers: detection of livestock- and healthcare-associated clones.

    PubMed

    Wettstein Rosenkranz, K; Rothenanger, E; Brodard, I; Collaud, A; Overesch, G; Bigler, B; Marschall, J; Perreten, V

    2014-07-01

    We screened a total of 340 veterinarians (including general practitioners, small animal practitioners, large animal practitioners, veterinarians working in different veterinary services or industry), and 29 veterinary assistants for nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus pseudintermedius (MRSP) at the 2012 Swiss veterinary annual meeting. MRSA isolates (n = 14) were detected in 3.8 % (95 % CI 2.1 - 6.3 %) of the participants whereas MRSP was not detected. Large animal practitioners were carriers of livestock-associated MRSA (LA-MRSA) ST398-t011-V (n = 2), ST398-t011-IV (n = 4), and ST398-t034-V (n = 1). On the other hand, participants working with small animals harbored human healthcare-associated MRSA (HCA-MRSA) which belonged to epidemic lineages ST225-t003-II (n = 2), ST225-t014-II (n = 1), ST5-t002-II (n = 2), ST5-t283-IV (n = 1), and ST88-t186-IV (n = 1). HCA-MRSA harbored virulence factors such as enterotoxins, β-hemolysin converting phage and leukocidins. None of the MRSA isolates carried Panton-Valentine leukocidin (PVL). In addition to the methicillin resistance gene mecA, LA-MRSA ST398 isolates generally contained additional antibiotic resistance genes conferring resistance to tetracycline [tet(M) and tet(K)], trimethoprim [dfrK, dfrG], and the aminoglycosides gentamicin and kanamycin [aac(6')-Ie - aph(2')-Ia]. On the other hand, HCA-MRSA ST5 and ST225 mainly contained genes conferring resistance to the macrolide, lincosamide and streptogramin B antibiotics [erm(A)], to spectinomycin [ant(9)-Ia], amikacin and tobramycin [ant(4')-Ia], and to fluoroquinolones [amino acid substitutions in GrlA (S84L) and GyrA (S80F and S81P)]. MRSA carriage may represent an occupational risk and veterinarians should be aware of possible MRSA colonization and potential for developing infection or for transmitting these strains. Professional exposure to animals should be reported upon hospitalization and before medical

  6. Risk factors for methicillin-resistant Staphylococcus aureus colonisation or infection in intensive care units and their reliability for predicting MRSA on ICU admission.

    PubMed

    Callejo-Torre, Fernando; Eiros Bouza, Jose Maria; Olaechea Astigarraga, Pedro; Coma Del Corral, Maria Jesus; Palomar Martínez, Mercedes; Alvarez-Lerma, Francisco; López-Pueyo, Maria Jesús

    2016-09-01

    Predicting methicillin-resistant Staphylococcus aureus (MRSA) in intensive care units (ICUs) avoids inappropriate antimicrobial empirical treatment and enhances infection control. We describe risk factors for colonisation/infection related to MRSA (MRSA-C/I) in critically ill patients once in the ICU and on ICU admission, and search for an easy-to-use predictive model for MRSA colonisation/infection on ICU admission. This multicentre cohort study included 69,894 patients admitted consecutively (stay>24h) in April-June in the five-year period 2006-2010 from 147 Spanish ICUs participating in the National Surveillance Study of Nosocomial Infections in ICUs (ENVIN-HELICS). Data from all patients included were used to identify risk factors for MRSA-C/I during ICU stays, from admission to discharge, using uni- and multivariable analysis (Poisson regression) to check that the sample to be used to develop the predictive models was representative of standard critical care population. To identify risk factors for MRSA-C/I on ICU admission and to develop prediction models, multivariable logistic regression analysis were then performed only on those admitted in 2010 (n=16950, 2/3 for analysis and 1/3 for subsequent validation). We found that, in the period 2006-2010, 1046 patients were MRSA-C/I. Independent risk factors for MRSA-C/I in ICU were: age>65, trauma or medical patient, high APACHE-II score, admitted from a long-term care facility, urinary catheter, previous antibiotic treatment and skin-soft tissue or post-surgical superficial skin infections. Colonisation with several different MDRs significantly increased the risk of MRSA-C/I. Risk factors on ICU admission were: male gender, trauma critical patient, urgent surgery, admitted from other ICUs, hospital ward or long-term facility, immunosuppression and skin-soft tissue infection. Although the best model to identify carriers of MRSA had a good discrimination (AUC-ROC, 0.77; 95% CI, 0.72-0.82), sensitivity was 67% and

  7. Multiclonal methicillin-resistant Staphylococcus aureus (MRSA) outbreak and its control after use of the Veterans Affairs (VA) MRSA bundle in a VA long-term care facility, 2004-2014.

    PubMed

    Webb, Risa M; Denton, Carmelita; Spruill, Emily; Henson, Gay; Bruce, Lisa; Woods, Gail L; Swiatlo, Andrea; Walker, Erica D; Peel, Chere; Sullivan, Donna

    2016-06-01

    A multiclonal methicillin-resistant Staphylococcus aureus (MRSA) outbreak with 91 infections occurred in our Veterans Affairs (VA) community living center over 46 months. Both similar and unique strains were shown by repetitive polymerase chain reaction to contribute to the outbreak, including 1 strain causing infections over a 33-month period. Most infections were soft tissue infections (67%). For 21 months after the initiation of the VA MRSA bundle, no infections were identified, and low rates of infection have been sustained an additional 4 years. The average annual rate of MRSA infection decreased by 62% (P < .001) from 0.6 per 1,000 resident days for 4 years prior to the bundle implementation to 0.09 per 1,000 resident days for 4 years after the bundle implementation.

  8. Recommendations for the prevention and control of methicillin-resistant Staphylococcus aureus isolates (MRSA) in hospitals and other healthcare facilities.

    PubMed

    2009-01-01

    The Commission for Hospital Hygiene and Infection Control (KRINKO) at the Robert Koch-Institute Berlin published the "Recommendations for Preventing and Controlling Methicillin-Resistant Staphylococcus aureus (MRSA) Strains in Hospitals and Other Medical Facilities" in the Federal Health Gazette in 1999 [1]. These recommendations were translated for the current edition of GMS Krankenhaushygiene Interdisziplinär by the German Society of Hospital Hygiene.KRINKO's work is legitimated by section sign 23 para. 2 of the Infection Protection Act. Regarding the legal nature of the KRINKO recommendations, it should be noted that they are neither a formal act or an administrative regulation. The KRINKO recommendations are instead an evidence-based consensus of particularly qualified experts. The consensus is reached by including the Federal States' authorities and all competent professional bodies and associations. This is to guarantee that the KRINKO recommendations reflect the state-of-the-art of medical science, and are met with a high degree of user acceptance. The recommendations are published in the Federal Health Gazette and on the RKI's Internet pages (http://www.rki.de/).Link to the German original edition of the MRSA recommendations. PMID:20204101

  9. Caco-2 cells permeability evaluation of nifuroxazide derivatives with potential activity against methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    B Fernandes, Mariane; Gonçalves, José E; C Tavares, Leoberto; Storpirtis, Sílvia

    2015-01-01

    Throughout the period of evaluation and selection in drug development, the assessment of the permeability potential of a compound to achieve an efficient refinement of the molecular structure has been widely appraised by the transport of substances across cell monolayers. This study aims to develop in vitro assays through Caco-2 cells in order to analyze the permeability of 5-nitro-heterocyclic compounds analogues to nifuroxazide with antimicrobial activity, especially showing promising activity against multidrug-resistant Staphylococcus aureus (MRSA). Caco-2 cell monolayers cultivated for 21 days in Transwell® plates were used for the in vitro permeability assays. The quantification of the nifuroxazide derivatives in the basolateral chambers was performed by a validated high performance liquid chromatography with UV (HPLC-UV) method. Apparent permeability values (Papp) show that these compounds can be considered as new drug candidates with the potential to present high absorption in vivo, according to the classifications of Yee and Biganzoli. The thiophenic derivatives showed permeability values higher than the furanic ones, being AminoTIO the compound with the greatest potential for the development of a new drug against MRSA, since it showed the best cytotoxicity, permeability and solubility ratio among all the derivatives. PMID:24918173

  10. Incidence and characterisation of methicillin-resistant Staphylococcus aureus (MRSA) from nasal colonisation in participants attending a cattle veterinary conference in the UK.

    PubMed

    Paterson, Gavin K; Harrison, Ewan M; Craven, Emily F; Petersen, Andreas; Larsen, Anders Rhod; Ellington, Matthew J; Török, M Estée; Peacock, Sharon J; Parkhill, Julian; Zadoks, Ruth N; Holmes, Mark A

    2013-01-01

    We sought to determine the prevalence of nasal colonisation with methicillin-resistant Staphylococcus aureus among cattle veterinarians in the UK. There was particular interest in examining the frequency of colonisation with MRSA harbouring mecC, as strains with this mecA homologue were originally identified in bovine milk and may represent a zoonotic risk to those in contact with dairy livestock. Three hundred and seven delegates at the British Cattle Veterinarian Association (BCVA) Congress 2011 in Southport, UK were screening for nasal colonisation with MRSA. Isolates were characterised by whole genome sequencing and antimicrobial susceptibility testing. Eight out of three hundred and seven delegates (2.6%) were positive for nasal colonisation with MRSA. All strains were positive for mecA and none possessed mecC. The time since a delegate's last visit to a farm was significantly shorter in the MRSA-positive group than in MRSA-negative counterparts. BCVA delegates have an increased risk of MRSA colonisation compared to the general population but their frequency of colonisation is lower than that reported from other types of veterinarian conference, and from that seen in human healthcare workers. The results indicate that recent visitation to a farm is a risk factor for MRSA colonisation and that mecC-MRSA are rare among BCVA delegates (<1% based on sample size). Contact with livestock, including dairy cattle, may still be a risk factor for human colonisation with mecC-MRSA but occurs at a rate below the lower limit of detection available in this study.

  11. Control and the prevention of methicillin-resistant Staphylococcus aureus in hospitals in Ireland: North/South Study of MRSA in Ireland 1999.

    PubMed

    Burd, M; Humphreys, H; Glynn, G; Mitchell, E; McDonald, P; Johnson, H; McDonnell, B; Doyle, D; Rossney, A

    2003-04-01

    As part of an all-island survey of methicillin-resistant Staphylococcus aureus (MRSA) in the Republic of Ireland (the South), where there is a mixed public and private healthcare system, and Northern Ireland (the North), where the healthcare system is part of the UK National Health Service, a questionnaire was circulated to all participating hospitals on measures routinely taken to control MRSA. Response rates were 100% in the North and 89% in the South. Over 70% of hospitals screened particular groups of patients on admission to hospital. Ninety-five percent of hospitals in the North and 88% in the South attempted to eradicate MRSA from carriage sites. Most hospitals attempted to isolate or cohort positive patients. About a quarter of hospitals in both parts of Ireland screened new healthcare workers for the presence of MRSA. Terminal decontamination of the environment after the discharge of a patient positive for MRSA was the norm in over 90% of hospitals, however, 6% of hospitals in the South used inappropriate disinfectants for MRSA. All hospitals in the North, but a minority (41%) in the South, had written antibiotic prescribing policies, but only 65% of hospitals in the South had access to an infection control committee, acute hospitals having greater access than district hospitals. The prevention and control of spread of MRSA remains a major challenge in the North and in the South. Although most hospitals in the North and in the South implemented current recommended guidelines on the control of MRSA in hospitals, there was some variability that may be resource related. Policies need to be reviewed in the light of the changing epidemiology of MRSA.

  12. Phenotypic and genomic comparisons of highly vancomycin-resistant Staphylococcus aureus strains developed from multiple clinical MRSA strains by in vitro mutagenesis

    PubMed Central

    Ishii, Kenichi; Tabuchi, Fumiaki; Matsuo, Miki; Tatsuno, Keita; Sato, Tomoaki; Okazaki, Mitsuhiro; Hamamoto, Hiroshi; Matsumoto, Yasuhiko; Kaito, Chikara; Aoyagi, Tetsuji; Hiramatsu, Keiichi; Kaku, Mitsuo; Moriya, Kyoji; Sekimizu, Kazuhisa

    2015-01-01

    The development of vancomycin (VCM) resistance in Staphylococcus aureus threatens global health. Studies of the VCM-resistance mechanism and alternative therapeutic strategies are urgently needed. We mutagenized S. aureus laboratory strains and methicillin-resistant S. aureus (MRSA) with ethyl methanesulfonate, and isolated mutants that exhibited high resistance to VCM (minimum inhibitory concentration = 32 μg/ml). These VCM-resistant strains were sensitive to linezolid and rifampicin, and partly to arbekacin and daptomycin. Beta-lactams had synergistic effects with VCM against these mutants. VCM-resistant strains exhibited a 2-fold increase in the cell wall thickness. Several genes were commonly mutated among the highly VCM-resistant mutants. These findings suggest that MRSA has a potential to develop high VCM resistance with cell wall thickening by the accumulation of mutations. PMID:26603341

  13. Phenotypic and genomic comparisons of highly vancomycin-resistant Staphylococcus aureus strains developed from multiple clinical MRSA strains by in vitro mutagenesis.

    PubMed

    Ishii, Kenichi; Tabuchi, Fumiaki; Matsuo, Miki; Tatsuno, Keita; Sato, Tomoaki; Okazaki, Mitsuhiro; Hamamoto, Hiroshi; Matsumoto, Yasuhiko; Kaito, Chikara; Aoyagi, Tetsuji; Hiramatsu, Keiichi; Kaku, Mitsuo; Moriya, Kyoji; Sekimizu, Kazuhisa

    2015-11-25

    The development of vancomycin (VCM) resistance in Staphylococcus aureus threatens global health. Studies of the VCM-resistance mechanism and alternative therapeutic strategies are urgently needed. We mutagenized S. aureus laboratory strains and methicillin-resistant S. aureus (MRSA) with ethyl methanesulfonate, and isolated mutants that exhibited high resistance to VCM (minimum inhibitory concentration = 32 μg/ml). These VCM-resistant strains were sensitive to linezolid and rifampicin, and partly to arbekacin and daptomycin. Beta-lactams had synergistic effects with VCM against these mutants. VCM-resistant strains exhibited a 2-fold increase in the cell wall thickness. Several genes were commonly mutated among the highly VCM-resistant mutants. These findings suggest that MRSA has a potential to develop high VCM resistance with cell wall thickening by the accumulation of mutations.

  14. Cost Analysis of an Intervention to Prevent Methicillin-Resistant Staphylococcus Aureus (MRSA) Transmission

    PubMed Central

    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

  15. Methicillin-Resistant Staphylococcus aureus (MRSA)-Active Metabolites from Platanus occidentalis (American Sycamore)

    PubMed Central

    Ibrahim, Mohamed A.; Mansoor, Arsala A.; Gross, Amanda; Ashfaq, M. Khalid; Jacob, Melissa; Khan, Shabana I.; Hamann, Mark T.

    2016-01-01

    One known and three new potent, selective, and nontoxic anti-MRSA metabolites, kaempferol 3-O-α-l-(2″,3″-di-E-p-coumaroyl)rhamnoside (1) (IC50 2.0 µg/mL), kaempferol 3-O-α-l-(2″-E-p-coumaroyl-3″-Z-p-coumaroyl)rhamnoside (2) (IC50 0.8 µg/mL), kaempferol 3-O-α-l-(2″-Z-p-coumaroyl-3″-E-p-coumaroyl)rhamnoside (3) (IC50 0.7 µg/mL), and kaempferol 3-O-α-l-(2″,3″-di-Z-p-coumaroyl)rhamnoside (4) (IC50 0.4 µg/mL), were isolated from the leaves of the common American sycamore, Platanus occidentalis. Compounds 2–4 are new. Due to the unusual selectivity, potency, and safety of the pure compounds and the semipure glycoside mixture against MRSA, it is clear that this represents a viable class of inhibitors to prevent growth of MRSA on surfaces and systemically. PMID:19904995

  16. Methicillin-resistant Staphylococcus aureus (MRSA)-active metabolites from Platanus occidentalis (American Sycamore).

    PubMed

    Ibrahim, Mohamed A; Mansoor, Arsala A; Gross, Amanda; Ashfaq, M Khalid; Jacob, Melissa; Khan, Shabana I; Hamann, Mark T

    2009-12-01

    One known and three new potent, selective, and nontoxic anti-MRSA metabolites, kaempferol 3-O-alpha-l-(2'',3''-di-E-p-coumaroyl)rhamnoside (1) (IC(50) 2.0 microg/mL), kaempferol 3-O-alpha-l-(2''-E-p-coumaroyl-3''-Z-p-coumaroyl)rhamnoside (2) (IC(50) 0.8 microg/mL), kaempferol 3-O-alpha-l-(2''-Z-p-coumaroyl-3''-E-p-coumaroyl)rhamnoside (3) (IC(50) 0.7 microg/mL), and kaempferol 3-O-alpha-l-(2'',3''-di-Z-p-coumaroyl)rhamnoside (4) (IC(50) 0.4 microg/mL), were isolated from the leaves of the common American sycamore, Platanus occidentalis. Compounds 2-4 are new. Due to the unusual selectivity, potency, and safety of the pure compounds and the semipure glycoside mixture against MRSA, it is clear that this represents a viable class of inhibitors to prevent growth of MRSA on surfaces and systemically.

  17. Metabolic footprint analysis uncovers strain specific overflow metabolism and D-isoleucine production of Staphylococcus aureus COL and HG001.

    PubMed

    Dörries, Kirsten; Lalk, Michael

    2013-01-01

    During infection processes, Staphylococcus aureus is able to survive within the host and to invade tissues and cells. For studying the interaction between the pathogenic bacterium and the host cell, the bacterial growth behaviour and its metabolic adaptation to the host cell environment provides first basic information. In the present study, we therefore cultivated S. aureus COL and HG001 in the eukaryotic cell culture medium RPMI 1640 and analyzed the extracellular metabolic uptake and secretion patterns of both commonly used laboratory strains. Extracellular accumulation of D-isoleucine was detected starting during exponential growth of COL and HG001 in RPMI medium. This non-canonical D-amino acid is known to play a regulatory role in adaptation processes. Moreover, individual uptake of glucose, accumulation of acetate, further overflow metabolites, and intermediates of the branched-chain amino acid metabolism constitute unique metabolic footprints. Altogether these time-resolved footprint analyses give first metabolic insights into staphylococcal growth behaviour in a culture medium used for infection related studies.

  18. Treatment of localized abscesses induced by methicillin-resistant Staphylococcus aureus (MRSA) using MRgFUS: First in vivo results

    NASA Astrophysics Data System (ADS)

    Rieck, Birgit; Curiel, Laura; Mougenot, Charles; Zhang, Kunyan; Pichardo, Samuel

    2012-11-01

    Background. In the present work we study the therapeutic effect of focused ultrasound on localized abscess induced by methicillin-resistant Staphylococcus aureus (MRSA). MRSA is a major nosocomial pathogen in health-care facilities. The people, particularly those who are immunocompromised are prone to develop infectious sites that often are non-responsive to regular treatments. Because of its capability to induce a rise of temperature at a very precise location, the use of focused ultrasound represents a considerable opportunity to propose a new therapy for MRSA-related infections. Methods. A 50μL subcutaneous injection of MRSA strain USA 400 bacteria at a concentration of 7×103/μL was made on the left thigh of BALB/c mice and an abscess of 6±2 mm-length formed after 48hrs. A transducer operating at 3 MHz with a focal length of 50mm and diameter of 32mm was used to treat the abscess. The focal point was positioned 2mm under the skin at the abscess center. Forty-eight hours after injection 4 ultrasound exposures of 9s-each were applied to each abscess under Magnetic Resonance-guidance. Each exposure was followed by a 1 min pause. Real-time estimation of change of temperature was done using a communication toolbox (matMRI) developed in our laboratory. Three experimental groups of 6 animals each were tested: moderate temperature (MT), high temperature (HT) and control. MT and HT groups reached, respectively, 55°C and 65°C at end of exposure. Effectiveness of the treatment was assessed by culturing bacteria of the treated abscess 1 and 4 days after treatment. Spleen samples were cultured to test for septicemia. Results. Macroscopic evaluation of treated abscess indicated a diminution of external size of abscess 1d after treatment. Treatment did not cause open wounds. Bacteria counting 1 day after treatment was 0.7±1.1 × 105, 0.5±0.7 × 105 and 1.1±2.3 × 105 CFU/μl for MT, HT and control groups, respectively; for the 4-day end point, the count was 0.6±0.6

  19. Formation and transmission of Staphylococcus aureus (including MRSA) aerosols carrying antibiotic-resistant genes in a poultry farming environment.

    PubMed

    Liu, Dunjiang; Chai, Tongjie; Xia, Xianzhu; Gao, Yuwei; Cai, Yumei; Li, Xiaoxia; Miao, Zengming; Sun, Lingyu; Hao, Haiyu; Roesler, Uwe; Wang, Jian

    2012-06-01

    There is a rather limited understanding concerning the antibiotic-resistance of the airborne S. aureus and the transmission of the antibiotic-resistant genes it carries Therefore, we isolated 149 S. aureus strains from the samples collected from the feces, the indoor air and the outdoor air of 6 chicken farms, and performed the research on them with 15 types of antibiotics and the REP-PCR trace identification. The 100% homologous strains were selected to conduct the research on the carrying and transmission status of the antibiotic-resistant genes. The results revealed that 5.37% strains (8/149) were resistant to methicillins (MRSA), and 94% strains (140/149) were resistant to compound sulfamethoxazole, etc. In addition, these strains displayed a resistance to multiple antibiotics (4, 5 or 6 types) and there were also 3 strains resistant to 9 antibiotics. It should be noted that the antibiotic-resistance of some strains isolated from the feces, the indoor and outdoor air was basically the same, and the strains with the same REP-PCR trace identification result carried the same type of antibiotic-resistant genes. The results showed that airborne transmission not only causes the spread of epidemic diseases but also exerts threats to the public health of a community.

  20. Detection of mecA and enterotoxin genes in Staphylococcus aureus isolates associated with bovine mastitis and characterization of Staphylococcal cassette chromosome mec (SCCmec) in MRSA strains.

    PubMed Central

    Havaei, Seyed Asghar; Assadbeigi, Behnaz; Esfahani, Bahram Nasr; Hoseini, Nafiseh Sadat; Rezaei, Nahid; Havaei, Seyed Rouhollah

    2015-01-01

    Background and Objectives: Staphylococcus aureus is one of the main causatives of bovine mastitis. Resistance of some strains to methicillin, can complicate the treatment of its infections. On the other hand, enterotoxin production is also important. Therefore, the aim of our study was to investigate the methicillin resistance and enterotoxin production in S. aureus isolates caused bovine mastitis. Materials and Methods: Four hundred and fifty milk samples were collected. After isolation of Staphylococcus aureus, MRSA strains were detected by cefoxitin disc diffusion and oxacillin agar screening methods. DNA was extracted by phenol – chloroform method and PCR was applied for mecA, sea and seb genes. SCCmec types of mecA gene were identified using multiplex-PCR. Results: Fifty-four (12%) S. aureus were isolated. Out of these, 10 and 9 MRSA strains identified by cefoxitin disc diffusion and oxacillin agar screening methods, respectively. All 10 MRSA isolates identified by cefoxitin disc diffusion, were positive for mecA gene and all of them belonged to SCCmec type IV. The sea genes were detected in 19 isolates and only two isolates were positive for seb genes. One isolate possessed both sea and seb genes. Conclusion: Findings of this study indicated that results of cefoxitin disc diffusion test is in concordance with the PCR for mecA gene and has a higher sensitivity compared to oxacillin agar screening method. Finally, Our findings suggest that enterotoxin A is the dominant type. PMID:26668704

  1. Screening cultures for detection of methicillin-resistant Staphylococcus aureus in a population at high risk for MRSA colonisation: identification of optimal combinations of anatomical sites.

    PubMed

    El-Bouri, Khalid; El-Bouri, Wahbi

    2013-11-26

    This retrospective study analysed the diagnostic yield of single-site, two-site, and three-site anatomical surveillance cultures in a population of 4,769 patients at high risk for methicillin-resistant Staphylococcus aureus (MRSA) colonisation. Cultures of seven anatomical sites were used as the gold standard against which to measure the sensitivity of MRSA detection. Detection rates for the seven single-sites, 21 two-site, and 35 three-site combinations are presented. Single-site swabbing only detected 50.5% (nose) of total cases, while three-site surveillance achieved a 92% (groin + nose + throat) sensitivity of detection at best. It is recommended that at least three anatomical sites should be screened for MRSA colonisation in these high-risk patients.

  2. Co-Therapy Using Lytic Bacteriophage and Linezolid: Effective Treatment in Eliminating Methicillin Resistant Staphylococcus aureus (MRSA) from Diabetic Foot Infections

    PubMed Central

    Chhibber, Sanjay; Kaur, Tarsem; Sandeep Kaur

    2013-01-01

    Background Staphylococcus aureus remains the predominant pathogen in diabetic foot infections and prevalence of methicillin resistant S.aureus (MRSA) strains further complicates the situation. The incidence of MRSA in infected foot ulcers is 15–30% and there is an alarming trend for its increase in many countries. Diabetes acts as an immunosuppressive state decreasing the overall immune functioning of body and to worsen the situation, wounds inflicted with drug resistant strains represent a morbid combination in diabetic patients. Foot infections caused by MRSA are associated with an increased risk of amputations, increased hospital stay, increased expenses and higher infection-related mortality. Hence, newer, safer and effective treatment strategies are required for treating MRSA mediated diabetic foot infections. The present study focuses on the use of lytic bacteriophage in combination with linezolid as an effective treatment strategy against foot infection in diabetic population. Methodology Acute hindpaw infection with S.aureus ATCC 43300 was established in alloxan induced diabetic BALB/c mice. Therapeutic efficacy of a well characterized broad host range lytic bacteriophage, MR-10 was evaluated alone as well as in combination with linezolid in resolving the course of hindpaw foot infection in diabetic mice. The process of wound healing was also investigated. Results and Conclusions A single administration of phage exhibited efficacy similar to linezolid in resolving the course of hindpaw infection in diabetic animals. However, combination therapy using both the agents was much more effective in arresting the entire infection process (bacterial load, lesion score, foot myeloperoxidase activity and histopathological analysis). The entire process of tissue healing was also hastened. Use of combined agents has been known to decrease the frequency of emergence of resistant mutants, hence this approach can serve as an effective strategy in treating MRSA mediated

  3. Synergistic effects of ovine-derived cathelicidins and other antimicrobials against Escherichia coli O157:H7 and Staphylococcus aureus 1056 MRSA.

    PubMed

    van der Linden, Danitsja S; Short, David; Dittmann, Antje; Yu, Pak-Lam

    2009-08-01

    Synergistic effects of ovine-derived cathelicidins SMAP29 and OaBac5mini with the antimicrobials polymyxin B, lysozyme, nisin and lactoferrin were investigated against E. coli O157:H7 and S. aureus 1056 MRSA. Lysozyme showed synergy against E. coli O157:H7 with SMAP29, polymyxin B and lactoferrin. Synergy was also found between SMAP29 and lactoferrin against this host. Against S. aureus 1056 MRSA, lysozyme showed synergy with OaBac5mini, polymyxin B and nisin, while synergy was also found between nisin and OaBac5mini and polymyxin B. Other combinations of the antimicrobials were either additive or non-synergistic. PMID:19396584

  4. Antibacterial and synergic effects of gallic acid-grafted-chitosan with β-lactams against methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Lee, Dae-Sung; Eom, Sung-Hwan; Kim, Young-Mog; Kim, Hye Seon; Yim, Mi-Jin; Lee, Sang-Hoon; Kim, Do-Hyung; Je, Jae-Young

    2014-10-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is spreading worldwide, emphasizing the need to search for new antibiotics. The anti-MRSA activities of gallic acid-grafted-chitosans (GA-g-chitosans) were investigated against 2 MRSA standards and 10 MRSA clinical isolates by determining the minimum inhibitory concentrations (MICs). GA-g-chitosan (I), which has the highest gallic acid content, exhibited the strongest anti-MRSA activities, with MICs of 32-64 μg/mL. A time-kill investigation revealed that GA-g-chitosan (I) exhibited a bactericidal effect at twice the MIC, also demonstrating good thermal and pH stability. Investigation of cell envelope integrity showed the release of intracellular components with an increasing absorbance value at 260 nm, indicating cell envelope damage caused by the GA-g-chitosan (I), which was further confirmed by transmission electron microscopy. When GA-g-chitosans were combined with β-lactams, including ampicillin and penicillin, synergistic effects were observed on the 2 standard MRSA strains and on the 10 clinical isolates, with fractional inhibitory indices ranging from 0.125 to 0.625. In the time-kill dynamic confirmation test, synergistic bactericidal effects were observed for the combinations of GA-g-chitosans with β-lactams, and over 4.0 log CFU/mL reductions were observed after 24 h when combination treatment was used. These results may prove GA-g-chitosans to be a potent agent when combined with ampicillin and penicillin for the elimination of MRSA.

  5. Assessment of the efficacy of polyclonal intravenous immunoglobulin G (IVIG) against the infectivity of clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) in vitro and in vivo.

    PubMed

    Farag, N; Mahran, L; Abou-Aisha, K; El-Azizi, M

    2013-09-01

    The response to treatment of severe methicillin-resistant Staphylococcus aureus (MRSA) infections with the traditional antibiotics is sometimes unsatisfactory and multiple antibiotic resistance is common. Adjuvant therapy such as intravenous immunoglobulin G (IVIG) could possibly be helpful in the treatment of such infections. The effect of IVIG on the capacity of human neutrophils to phagocytose and kill MRSA was investigated in vitro using the MTT assay and measuring the production of reactive oxygen species (ROS) and nitric oxide (NO). The efficiency of IVIG in neutralizing α-hemolysin and coagulase of MRSA was also assessed. The capability of IVIG in the treatment and prevention of MRSA infections was also evaluated in a murine peritonitis model. IVIG significantly enhanced (p < 0.01) the killing of MRSA by neutrophils at all concentrations tested (0.1-5 mg/ml) by 30-80 % of control values. It significantly (p < 0.01) increased the level of NO production in a dose-dependent manner, giving up to 60 μM at 5 mg/ml. The ROS level significantly increased (p < 0.01) in the presence of IVIG. In addition, IVIG significantly reduced the hemolytic activity of MRSA 10-fold and its coagulation capabilities by 50 %. When tested in vivo, groups receiving IVIG via tail vein infusion showed no significant improvement in their survival. Only when delivered to the same site of infection did IVIG show an improvement in the survival of mice (n = 80). These results could pave the way for a better understanding of the mechanism of action of IVIG and suggest its clinical potential as an adjuvant preventive and therapeutic agent against life-threatening infections caused by MRSA and other bacteria.

  6. Emergence of clonal complex 5 (CC5) methicillin-resistant Staphylococcus aureus (MRSA) isolates susceptible to trimethoprim-sulfamethoxazole in a Brazilian hospital.

    PubMed

    Teixeira, M M; Araújo, M C; Silva-Carvalho, M C; Beltrame, C O; Oliveira, C C H B; Figueiredo, A M S; Oliveira, A G

    2012-07-01

    In this study, genotyping techniques including staphylococcal chromosomal cassette mec (SCCmec) typing, pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST) and restriction-modification tests were used to compare the molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) isolates recovered at two times within a 10-year interval (1998 and 2008) from a tertiary Brazilian hospital. In addition, the antimicrobial susceptibility profiles were analyzed. All 48 MRSA isolates from 1998 and 85.7% from 2008 (48/56 isolates) displayed multidrug-resistance phenotypes and SCCmec III. All but one of the 13 representative SCCmec III isolates belonged to CC8 and had PFGE patterns similar to that of the BMB9393 strain (Brazilian epidemic clone of MRSA; BEC). In 2008, we found an increased susceptibility to rifampicin and chloramphenicol among the SCCmec III isolates. In addition, we detected the entrance of diverse international MRSA lineages susceptible to trimethoprim-sulfamethoxazole (SXT), almost all belonging to CC5. These non-SCCmec III isolates were related to the USA 300 (ST8-SCCmec IV; PFGE-type B), USA 800 (ST5-SCCmec IV; subtype D1), USA 100 (ST5-SCCmec II; subtype D2), and EMRSA-3/Cordobes (ST5-SCCmec I, type C) clones. To the best of our knowledge, this is the first report of the emergence of isolates genetically related to the EMRSA-3/Cordobes clone in southeast Brazil. In this regard, these isolates were the most common non-SCCmec III MRSA in our institution, accounting for 8.9% of all isolates recovered in 2008. Thus, despite the supremacy of BEC isolates in our country, significant changes may occur in local MRSA epidemiology, with possible consequences for the rationality of MRSA empiric therapy.

  7. Hospital-wide infection control practice and Meticillin-resistant Staphylococcus aureus (MRSA) in the intensive care unit (ICU): an observational study

    PubMed Central

    Workman, Rella

    2014-01-01

    Summary Objectives To estimate trends in infection/colonisation with meticillin-resistant Staphylococcus aureus (MRSA) in an intensive care unit (ICU). Design Observational study of results of ICU admission and weekly screens for MRSA. Setting and Participants All ICU admissions in 2001–2012. Interventions ICU admissions were screened for MRSA throughout. In late 2006, screening was extended to the whole hospital and extra measures taken in ICU. Main outcome measures Prevalence of MRSA in ICU admissions and number acquiring MRSA therein. Results In all, 366 of 6565 admissions to ICU were MRSA positive, including 270 of 4466 coming from within the hospital in which prevalence increased with time prior to transfer to ICU. Prevalence in this group was 9.4% (8.2–10.6) in 2001–2006, decreasing to 3.4% (2.3–4.5) in 2007–2009 and 1.3% (0.6–2.0) in 2010–2012, p < 0.001, due to decreased prevalence in those spending >5 days on wards before ICU admission: 18.9% (15.6–22.2) in 2001–2006, 7.1% (4.0–10.2) in 2007–2009 and 1.6% (0.1–3.1) in 2010–2012, p < 0.001. In addition, 201 patients acquired MRSA within ICU, the relative risk being greater when known positives present: 4.34 (3.98–4.70), p < 0.001. Acquisition rate/1000 bed days decreased from 13.3 (11.2–15.4) in 2001–2006 to 3.6 (2.6–4.6) in 2007–2012, p < 0.0001. Of 41 ICU-acquired MRSA bacteraemias, 38 were in 2001–2006. The risk of bacteraemia in those acquiring MRSA decreased from 25% (18.1–31.9) in 2001–2006 to 6.1% (0–12.8) thereafter, p = 0.022. Conclusions Following better hospital-wide infection control, fewer MRSA-positive patients were admitted to ICU with a parallel decrease in acquisition therein. Better practice there reduced the risk of bacteraemia. PMID:25383196

  8. Decolonisation of MRSA, S. aureus and E. coli by Cold-Atmospheric Plasma Using a Porcine Skin Model In Vitro

    PubMed Central

    Maisch, Tim; Shimizu, Tetsuji; Li, Yang-Fang; Heinlin, Julia; Karrer, Sigrid; Morfill, Gregor; Zimmermann, Julia L.

    2012-01-01

    In the last twenty years new antibacterial agents approved by the U.S. FDA decreased whereas in parallel the resistance situation of multi-resistant bacteria increased. Thus, community and nosocomial acquired infections of resistant bacteria led to a decrease in the efficacy of standard therapy, prolonging treatment time and increasing healthcare costs. Therefore, the aim of this work was to demonstrate the applicability of cold atmospheric plasma for decolonisation of Gram-positive (Methicillin-resistant Staphylococcus aureus (MRSA), Methicillin-sensitive Staphylococcus aureus) and Gram-negative bacteria (E. coli) using an ex vivo pig skin model. Freshly excised skin samples were taken from six month old female pigs (breed: Pietrain). After application of pure bacteria on the surface of the explants these were treated with cold atmospheric plasma for up to 15 min. Two different plasma devices were evaluated. A decolonisation efficacy of 3 log10 steps was achieved already after 6 min of plasma treatment. Longer plasma treatment times achieved a killing rate of 5 log10 steps independently from the applied bacteria strains. Histological evaluations of untreated and treated skin areas upon cold atmospheric plasma treatment within 24 h showed no morphological changes as well as no significant degree of necrosis or apoptosis determined by the TUNEL-assay indicating that the porcine skin is still vital. This study demonstrates for the first time that cold atmospheric plasma is able to very efficiently kill bacteria applied to an intact skin surface using an ex vivo porcine skin model. The results emphasize the potential of cold atmospheric plasma as a new possible treatment option for decolonisation of human skin from bacteria in patients in the future without harming the surrounding tissue. PMID:22558091

  9. Caco-2 cells cytotoxicity of nifuroxazide derivatives with potential activity against Methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Fernandes, Mariane B; Gonçalves, José E; Scotti, Marcus T; de Oliveira, Alex A; Tavares, Leoberto C; Storpirtis, Sílvia

    2012-04-01

    It is important to determine the toxicity of compounds and co-solvents that are used in cell monolayer permeability studies to increase confidence in the results obtained from these in vitro experiments. This study was designed to evaluate the cytotoxicity of new nifuroxazide derivatives with potential activity against Methicillin-resistant Staphylococcus aureus (MRSA) in Caco-2 cells to select analogues for further in vitro permeability analyses. In this study, nitrofurantoin and nifuroxazide, in addition to 6 furanic and 6 thiophenic nifuroxazide derivatives were tested at 2, 4, 6, 8 and 10 μg/mL. In vitro cytotoxicity assays were performed according to the MTT (methyl tetrazolium) assay protocol described in ISO 10993-5. The viability of treated Caco-2 cells was greater than 83% for all tested nitrofurantoin concentrations, while those treated with nifuroxazide at 2, 4 and 6 μg/mL had viabilities greater than 70%. Treatment with the nifuroxazide analogues resulted in viability values greater than 70% at 2 and 4 μg/mL with the exception of the thiophenic methyl-substituted derivative, which resulted in cell viabilities below 70% at all tested concentrations. Caco-2 cells demonstrated reasonable viability for all nifuroxazide derivatives, except the thiophenic methyl-substituted compound. The former were selected for further permeability studies using Caco-2 cells. PMID:22285235

  10. Detection of mecC-Positive Staphylococcus aureus (CC130-MRSA-XI) in Diseased European Hedgehogs (Erinaceus europaeus) in Sweden

    PubMed Central

    Monecke, Stefan; Gavier-Widen, Dolores; Mattsson, Roland; Rangstrup-Christensen, Lena; Lazaris, Alexandros; Coleman, David C.; Shore, Anna C.; Ehricht, Ralf

    2013-01-01

    Recently, a novel mec gene conferring beta-lactam resistance in Staphylococcus aureus has been discovered. This gene, mecC, is situated on a SCCmec XI element that has to date been identified in clonal complexes 49, 130, 425, 599 and 1943. Some of the currently known isolates have been identified from animals. This, and observations of mecA alleles that do not confer beta-lactam resistance, indicate that mec genes might have a reservoir in Staphylococcus species from animals. Thus it is important also to screen wildlife isolates for mec genes. Here, we describe mecC-positive Staphylococcus aureus (ST130-MRSA-XI) and the lesions related to the infection in two diseased free-ranging European hedgehogs (Erinaceus europaeus). One was found dead in 2003 in central Sweden, and suffered from S. aureus septicaemia. The other one, found on the island of Gotland in the Baltic Sea in 2011, showed a severe dermatitis and was euthanised. ST130-MRSA-XI isolates were isolated from lesions from both hedgehogs and were essentially identical to previously described isolates from humans. Both isolates carried the complete SCCmec XI element. They lacked the lukF-PV/lukS-PV and lukM/lukF-P83 genes, but harboured a gene for an exfoliative toxin homologue previously described from Staphylococcus hyicus, Staphylococcus pseudintermedius and other S. aureus of the CC130 lineage. To the best of our knowledge, these are the first reported cases of CC130-MRSA-XI in hedgehogs. Given that one of the samples was taken as early as 2003, this was the earliest detection of this strain and of mecC in Sweden. This and several other recent observations suggest that CC130 might be a zoonotic lineage of S. aureus and that SCCmec XI/mecC may have originated from animal pathogens. PMID:23776626

  11. Detection of mecC-positive Staphylococcus aureus (CC130-MRSA-XI) in diseased European hedgehogs (Erinaceus europaeus) in Sweden.

    PubMed

    Monecke, Stefan; Gavier-Widen, Dolores; Mattsson, Roland; Rangstrup-Christensen, Lena; Lazaris, Alexandros; Coleman, David C; Shore, Anna C; Ehricht, Ralf

    2013-01-01

    Recently, a novel mec gene conferring beta-lactam resistance in Staphylococcus aureus has been discovered. This gene, mecC, is situated on a SCCmec XI element that has to date been identified in clonal complexes 49, 130, 425, 599 and 1943. Some of the currently known isolates have been identified from animals. This, and observations of mecA alleles that do not confer beta-lactam resistance, indicate that mec genes might have a reservoir in Staphylococcus species from animals. Thus it is important also to screen wildlife isolates for mec genes. Here, we describe mecC-positive Staphylococcus aureus (ST130-MRSA-XI) and the lesions related to the infection in two diseased free-ranging European hedgehogs (Erinaceus europaeus). One was found dead in 2003 in central Sweden, and suffered from S. aureus septicaemia. The other one, found on the island of Gotland in the Baltic Sea in 2011, showed a severe dermatitis and was euthanised. ST130-MRSA-XI isolates were isolated from lesions from both hedgehogs and were essentially identical to previously described isolates from humans. Both isolates carried the complete SCCmec XI element. They lacked the lukF-PV/lukS-PV and lukM/lukF-P83 genes, but harboured a gene for an exfoliative toxin homologue previously described from Staphylococcus hyicus, Staphylococcus pseudintermedius and other S. aureus of the CC130 lineage. To the best of our knowledge, these are the first reported cases of CC130-MRSA-XI in hedgehogs. Given that one of the samples was taken as early as 2003, this was the earliest detection of this strain and of mecC in Sweden. This and several other recent observations suggest that CC130 might be a zoonotic lineage of S. aureus and that SCCmec XI/mecC may have originated from animal pathogens.

  12. ST2249-MRSA-III: a second major recombinant methicillin-resistant Staphylococcus aureus clone causing healthcare infection in the 1970s.

    PubMed

    Nimmo, G R; Steen, J A; Monecke, S; Ehricht, R; Slickers, P; Thomas, J C; Appleton, S; Goering, R V; Robinson, D A; Coombs, G W

    2015-05-01

    Typing of healthcare-associated methicillin-resistant Staphylococcus aureus (MRSA) from Australia in the 1970s revealed a novel clone, ST2249-MRSA-III (CC45), present from 1973 to 1979. This clone was present before the Australian epidemic caused by the recombinant clone, ST239-MRSA-III. This study aimed to characterize the genome of ST2249-MRSA-III to establish its relationship to other MRSA clones. DNA microarray analysis was conducted and a draft genome sequence of ST2249 was obtained. The recombinant structure of the ST2249 genome was revealed by comparisons to publicly available ST239 and ST45 genomes. Microarray analysis of genomic DNA of 13 ST2249 isolates showed gross similarities with the ST239 chromosome in a segment around the origin of replication and with ST45 for the remainder of the chromosome. Recombination breakpoints were precisely determined by the changing pattern of nucleotide polymorphisms in the genome sequence of ST2249 isolate SK1585 compared with ST239 and ST45. One breakpoint was identified to the right of oriC, between sites 1014 and 1065 of the gene D484_00045. Another was identified to the left of oriC, between sites 1185 and 1248 of D484_01632. These results indicate that ST2249 inherited approximately 35.3% of its chromosome from an ST239-like parent and 64.7% from an ST45-like parent. ST2249-MRSA-III resulted from a major recombination between parents that resemble ST239 and ST45. Although only limited Australian archival material is available, the oldest extant isolate of ST2249 predates the oldest Australian isolate of ST239 by 3 years. It is therefore plausible that these two recombinant clones were introduced into Australia separately.

  13. Methicillin-resistant Staphylococcus aureus (MRSA) nasal real-time PCR: a predictive tool for contamination of the hospital environment.

    PubMed

    Livorsi, Daniel J; Livorsi, David J; Arif, Sana; Garry, Patricia; Kundu, Madan G; Satola, Sarah W; Davis, Thomas H; Batteiger, Byron; Kressel, Amy B

    2015-01-01

    OBJECTIVE We sought to determine whether the bacterial burden in the nares, as determined by the cycle threshold (CT) value from real-time MRSA PCR, is predictive of environmental contamination with MRSA. METHODS Patients identified as MRSA nasal carriers per hospital protocol were enrolled within 72 hours of room admission. Patients were excluded if (1) nasal mupirocin or chlorhexidine body wash was used within the past month or (2) an active MRSA infection was suspected. Four environmental sites, 6 body sites and a wound, if present, were cultured with premoistened swabs. All nasal swabs were submitted for both a quantitative culture and real-time PCR (Roche Lightcycler, Indianapolis, IN). RESULTS At study enrollment, 82 patients had a positive MRSA-PCR. A negative correlation of moderate strength was observed between the CT value and the number of MRSA colonies in the nares (r=-0.61; P<0.01). Current antibiotic use was associated with lower levels of MRSA nasal colonization (CT value, 30.2 vs 27.7; P<0.01). Patients with concomitant environmental contamination had a higher median log MRSA nares count (3.9 vs 2.5, P=0.01) and lower CT values (28.0 vs 30.2; P<0.01). However, a ROC curve was unable to identify a threshold MRSA nares count that reliably excluded environmental contamination. CONCLUSIONS Patients with a higher burden of MRSA in their nares, based on the CT value, were more likely to contaminate their environment with MRSA. However, contamination of the environment cannot be predicted solely by the degree of MRSA nasal colonization.

  14. Potent in vitro synergism of fusidic acid (FA) and berberine chloride (BBR) against clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Liang, Rong-mei; Yong, Xiao-lan; Duan, Yu-qin; Tan, Yong-hong; Zeng, Ping; Zhou, Zi-ying; Jiang, Yan; Wang, Shi-hua; Jiang, Yun-ping; Huang, Xiao-chun; Dong, Zhao-hui; Hu, Ting-ting; Shi, Hui-qing; Li, Nan

    2014-11-01

    It was found in the present study that combined use of fusidic acid (FA) and berberine chloride (BBR) offered an in vitro synergistic action against 7 of the 30 clinical methicillin-resistant Staphylococcus aureus (MRSA) strains, with a fractional inhibitory concentration (FIC) index ranging from 0.5 to 0.19. This synergistic effect was most pronounced on MRSA 4806, an FA-resistant isolate, with a minimum inhibitory concentration (MIC) value of 1,024 μg/ml. The time-kill curve experiment showed that FA plus BBR yielded a 4.2 log10 c.f.u./ml reduction in the number of MRSA 4806 bacteria after 24-h incubation as compared with BBR alone. Viable count analysis showed that FA plus BBR produced a 3.0 log10 c.f.u./ml decrease in biofilm formation and a 1.5 log10 c.f.u./ml decrease in mature biofilm in viable cell density as compared with BBR alone. In addition, phase contrast micrographs confirmed that biofilm formation was significantly inhibited and mature biofilm was obviously destructed when FA was used in combination with BBR. These results provide evidence that combined use of FA and BBR may prove to be a promising clinical therapeutic strategy against MRSA.

  15. Prevalence and clonality of methicillin-resistant Staphylococcus aureus (MRSA) in the Atlantic Azores islands: predominance of SCCmec types IV, V and VI.

    PubMed

    Conceição, T; Tavares, A; Miragaia, M; Hyde, K; Aires-de-Sousa, M; de Lencastre, H

    2010-05-01

    In order to obtain insights into the methicillin-resistant Staphylococcus aureus (MRSA) population structure in the Azores archipelago, 106 MRSA isolates were collected from patients attending an Azorean central hospital between January 2007 and February 2008. Antimicrobial resistance was determined for all isolates. Molecular typing was performed by pulsed-field gel electrophoresis (PFGE), spa typing, multilocus sequence typing (MLST), staphylococcal chromosome cassette mec (SCCmec) typing and the presence of Panton-Valentine leukocidin (PVL). The majority of the isolates (87%, n = 92) belonged to the EMRSA-15 clone (ST22, SCCmec-IVh), followed by the Pediatric clone (ST5-VI/IVc) (11%, n = 12). The Berlin clone (ST45-IVa) and a new clone (spa type t1839, ST1339 and SCCmec V variant) were represented by single isolates. All of the isolates carried SCCmec types IV, V or VI and a non-multiresistant antibiotic profile, resembling the currently emerging community MRSA. Moreover, PVL was described for the first time to be associated with the Pediatric clone carrying SCCmec type VI. We provided the first description of the population structure of MRSA in the Azores islands, which seems to be shaped by genetic events occurring locally, as well as by the regular population exchange between the islands, continental Portugal, the United Kingdom and the United States. PMID:20229224

  16. Characteristics of Community-Associated Methicillin-Resistant Staphylococcus aureus (CA-MRSA) Strains Isolated from Skin and Soft-Tissue Infections in Uruguay

    PubMed Central

    Pardo, Lorena; Machado, Virginia; Mollerach, Marta; Mota, María Inés; Tuchscherr, Lorena P. N.; Gadea, Pilar; Gardella, Noella; Sordelli, Daniel O.; Vola, Magdalena; Schelotto, Felipe; Varela, Gustavo

    2009-01-01

    We analyzed 90 nonduplicates community-associated methicillin-resistant S. aureus (CA-MRSA) strains isolated from skin and soft-tissue infections. All strains were mecA positive. Twenty-four of the 90 strains showed inducible macrolide-lincosamide-streptogramin B resistance. All strains produced α-toxin; 96% and 100% of them displayed positive results for lukS-F and cna genes, respectively. Eigthy-five strains expressed capsular polysaccharide serotype 8. Six different pulsotypes were discriminated by pulsed-field gel electrophoresis (PFGE) and three predominant groups of CA-MRSA strains (1, 2, and 4) were identified, in agreement with phenotypic and genotypic characteristics. Strains of group 1 (pulsotype A, CP8+, and Panton-Valentine leukocidin (PVL)+) were the most frequently recovered and exhibited a PFGE band pattern identical to other CA-MRSA strains previously isolated in Uruguay and Brazil. Three years after the first local CA-MRSA report, these strains are still producing skin and soft-tissue infections demonstrating the stability over time of this community-associated emerging pathogen. PMID:20016669

  17. In Vivo Assessment of Phage and Linezolid Based Implant Coatings for Treatment of Methicillin Resistant S. aureus (MRSA) Mediated Orthopaedic Device Related Infections.

    PubMed

    Kaur, Sandeep; Harjai, Kusum; Chhibber, Sanjay

    2016-01-01

    Staphylococcus comprises up to two-thirds of all pathogens in orthopaedic implant infections with two species respectively Staphylococcus aureus and Staphylococcus epidermidis, being the predominate etiological agents isolated. Further, with the emergence of methicillin-resistant S. aureus (MRSA), treatment of S. aureus implant infections has become more difficult, thus representing a devastating complication. Use of local delivery system consisting of S.aureus specific phage along with linezolid (incorporated in biopolymer) allowing gradual release of the two agents at the implant site represents a new, still unexplored treatment option (against orthopaedic implant infections) that has been studied in an animal model of prosthetic joint infection. Naked wire, hydroxypropyl methylcellulose (HPMC) coated wire and phage and /or linezolid coated K-wire were surgically implanted into the intra-medullary canal of mouse femur bone of respective groups followed by inoculation of S.aureus ATCC 43300(MRSA). Mice implanted with K-wire coated with both the agents i.e phage as well as linezolid (dual coated wires) showed maximum reduction in bacterial adherence, associated inflammation of the joint as well as faster resumption of locomotion and motor function of the limb. Also, all the coating treatments showed no emergence of resistant mutants. Use of dual coated implants incorporating lytic phage (capable of self-multiplication) as well as linezolid presents an attractive and aggressive early approach in preventing as well as treating implant associated infections caused by methicillin resistant S. aureus strains as assessed in a murine model of experimental joint infection. PMID:27333300

  18. In Vivo Assessment of Phage and Linezolid Based Implant Coatings for Treatment of Methicillin Resistant S. aureus (MRSA) Mediated Orthopaedic Device Related Infections

    PubMed Central

    Kaur, Sandeep; Harjai, Kusum; Chhibber, Sanjay

    2016-01-01

    Staphylococcus comprises up to two-thirds of all pathogens in orthopaedic implant infections with two species respectively Staphylococcus aureus and Staphylococcus epidermidis, being the predominate etiological agents isolated. Further, with the emergence of methicillin-resistant S. aureus (MRSA), treatment of S. aureus implant infections has become more difficult, thus representing a devastating complication. Use of local delivery system consisting of S.aureus specific phage along with linezolid (incorporated in biopolymer) allowing gradual release of the two agents at the implant site represents a new, still unexplored treatment option (against orthopaedic implant infections) that has been studied in an animal model of prosthetic joint infection. Naked wire, hydroxypropyl methylcellulose (HPMC) coated wire and phage and /or linezolid coated K-wire were surgically implanted into the intra-medullary canal of mouse femur bone of respective groups followed by inoculation of S.aureus ATCC 43300(MRSA). Mice implanted with K-wire coated with both the agents i.e phage as well as linezolid (dual coated wires) showed maximum reduction in bacterial adherence, associated inflammation of the joint as well as faster resumption of locomotion and motor function of the limb. Also, all the coating treatments showed no emergence of resistant mutants. Use of dual coated implants incorporating lytic phage (capable of self-multiplication) as well as linezolid presents an attractive and aggressive early approach in preventing as well as treating implant associated infections caused by methicillin resistant S. aureus strains as assessed in a murine model of experimental joint infection. PMID:27333300

  19. A clonal complex 12 methicillin-resistant Staphylococcus aureus strain, West Australian MRSA-59, harbors a novel pseudo-SCCmec element.

    PubMed

    Monecke, Stefan; Coombs, Geoffrey W; Pearson, Julie; Hotzel, Helmut; Slickers, Peter; Ehricht, Ralf

    2015-11-01

    A West Australian methicillin-resistant Staphylococcus aureus strain (WA MRSA-59) was characterized by microarray and sequencing. Its pseudo-staphylococcal cassette chromosome mec (SCCmec) element comprised dcs, Q9XB68-dcs, mvaS-SCC, Q5HJW6, dru, ugpQ, ydeM, mecA-mecR-mecI, txbi mecI, tnp IS431, copA2-mco (copper resistance), ydhK, arsC-arsB-arsR (arsenic resistance), open reading frame PT43, and per-2. Recombinase genes, xylR (mecR2), and PSM-mec (phenol-soluble modulin) were absent. We suggest that mec complex A should be split into two subtypes. One harbors PSM-mec and xylR (mecR2). It is found in SCCmec types II, III, and VIII. The second subtype, described herein, is present in WA MRSA-59 and some coagulase-negative staphylococci.

  20. Diversity of Methicillin-Resistant Staphylococcus aureus (MRSA) Strains Isolated from Inpatients of 30 Hospitals in Orange County, California

    PubMed Central

    Hudson, Lyndsey O.; Murphy, Courtney R.; Spratt, Brian G.; Enright, Mark C.; Elkins, Kristen; Nguyen, Christopher; Terpstra, Leah; Gombosev, Adrijana; Kim, Diane; Hannah, Paul; Mikhail, Lydia; Alexander, Richard; Moore, Douglas F.; Huang, Susan S.

    2013-01-01

    There is a need for a regional assessment of the frequency and diversity of MRSA to determine major circulating clones and the extent to which community and healthcare MRSA reservoirs have mixed. We conducted a prospective cohort study of inpatients in Orange County, California, systematically collecting clinical MRSA isolates from 30 hospitals, to assess MRSA diversity and distribution. All isolates were characterized by spa typing, with selective PFGE and MLST to relate spa types with major MRSA clones. We collected 2,246 MRSA isolates from hospital inpatients. This translated to 91/10,000 inpatients with MRSA and an Orange County population estimate of MRSA inpatient clinical cultures of 86/100,000 people. spa type genetic diversity was heterogeneous between hospitals, and relatively high overall (72%). USA300 (t008/ST8), USA100 (t002/ST5) and a previously reported USA100 variant (t242/ST5) were the dominant clones across all Orange County hospitals, representing 83% of isolates. Fifteen hospitals isolated more t008 (USA300) isolates than t002/242 (USA100) isolates, and 12 hospitals isolated more t242 isolates than t002 isolates. The majority of isolates were imported into hospitals. Community-based infection control strategies may still be helpful in stemming the influx of traditionally community-associated strains, particularly USA300, into the healthcare setting. PMID:23637976

  1. Bronchial aspirates glucose level as indicator for methicillin-resistant Staphylococcus aureus (MRSA) in intubated mechanically ventilated patients.

    PubMed

    Alsayed, Sherif; Marzouk, Samar; Mousa, Essam; Ragab, Ashraf

    2014-08-01

    This study evaluated if the level of glucose in bronchial aspirate serves as indicator for the risk of MRSA infection in intubated mechanically ventilated ICU patients. A total of 50 critically ill patients was enrolled and were under tight glycemic control to abolish the effect of hyperglycemia on bronchial secretion, if they were expected to require mechanical ventilation for more than 48 hours. Bronchial aspirates were detected for glucose and sent twice weekly for microbiological analysis and whenever an MRSA was expected. The results showed that all the patients had glucose tested in bronchial aspirates. Glucose was detected in bronchial aspirates of 28 of the 50 patients. Glucose in bronchial aspirates in these patients ranged between (2.9-5.1 mmol/l). MRSA was detected in 22 patients where 28 were MRSA free of the MRSA patients 19 had positive glucose where glucose was positive in 28 patients of them 19 (86.4%) where MRSA positive to 9 with no MRSA (32.1%).The risk of having MRSA present markedly increased significantly in the presence of glucose: (p value .001). PMID:25597152

  2. Discovery of Potent Benzofuran-Derived Diapophytoene Desaturase (CrtN) Inhibitors with Enhanced Oral Bioavailability for the Treatment of Methicillin-Resistant Staphylococcus aureus (MRSA) Infections.

    PubMed

    Wang, Youxin; Chen, Feifei; Di, Hongxia; Xu, Yong; Xiao, Qiang; Wang, Xuehai; Wei, Hanwen; Lu, Yanli; Zhang, Lingling; Zhu, Jin; Sheng, Chunquan; Lan, Lefu; Li, Jian

    2016-04-14

    Blocking the staphyloxanthin biosynthesis process has emerged as a new promising antivirulence strategy. Previously, we first revealed that CrtN is a druggable target against infections caused by pigmented Staphylococcus aureus (S. aureus) and that naftifine was an effective CrtN inhibitor. Here, we identify a new type of benzofuran-derived CrtN inhibitor with submicromolar IC50 values that is based on the naftifine scaffold. The most potent analog, 5m, inhibits the pigment production of S. aureus Newman and three MRSA strains, with IC50 values of 0.38-5.45 nM, without any impact on the survival of four strains (up to 200 μM). Notably, compound 5m (1 μM) could significantly sensitize four strains to immune clearance and could effectively attenuate the virulence of three strains in vivo. Moreover, 5m was determined to be a weak antifungal reagent (MIC > 16 μg/mL). Combined with good oral bioavailability (F = 42.2%) and excellent safety profiles, these data demonstrate that 5m may be a good candidate for the treatment of MRSA infections.

  3. Methicillin-resistant Staphylococcus aureus (MRSA) contamination in bedside surfaces of a hospital ward and the potential effectiveness of enhanced disinfection with an antimicrobial polymer surfactant.

    PubMed

    Yuen, John W M; Chung, Terence W K; Loke, Alice Y

    2015-03-11

    The aim in this study was to assess the effectiveness of a quaternary ammonium chloride (QAC) surfactant in reducing surface staphylococcal contamination in a routinely operating medical ward occupied by patients who had tested positive for methicillin-resistant Staphylococcus aureus (MRSA). The QAC being tested is an antibacterial film that is sprayed onto a surface and can remain active for up to 8 h. A field experimental study was designed with the QAC plus daily hypochlorite cleaning as the experimental group and hypochlorite cleaning alone as the control group. The method of swabbing on moistened surfaces was used for sampling. It was found that 83% and 77% of the bedside surfaces of MRSA-positive and MRSA-negative patients respectively were contaminated with staphylococci at 08:00 hours, and that the staphylococcal concentrations increased by 80% at 1200 h over a 4-hour period with routine ward and clinical activities. Irrespective of the MRSA status of the patients, high-touch surfaces around the bed-units within the studied medical ward were heavily contaminated (ranged 1 to 276 cfu/cm2 amongst the sites with positive culture) with staphylococcal bacteria including MRSA, despite the implementation of daily hypochlorite wiping. However, the contamination rate dropped significantly from 78% to 11% after the application of the QAC polymer. In the experimental group, the mean staphylococcal concentration of bedside surfaces was significantly (p<0.0001) reduced from 4.4±8.7 cfu/cm2 at 08:00 hours to 0.07±0.26 cfu/cm2 at 12:00 hours by the QAC polymer. The results of this study support the view that, in addition to hypochlorite wiping, the tested QAC surfactant is a potential environmental decontamination strategy for preventing the transmission of clinically important pathogens in medical wards.

  4. Methicillin-Resistant Staphylococcus aureus (MRSA) Contamination in Bedside Surfaces of a Hospital Ward and the Potential Effectiveness of Enhanced Disinfection with an Antimicrobial Polymer Surfactant

    PubMed Central

    Yuen, John W. M.; Chung, Terence W. K.; Loke, Alice Y.

    2015-01-01

    The aim in this study was to assess the effectiveness of a quaternary ammonium chloride (QAC) surfactant in reducing surface staphylococcal contamination in a routinely operating medical ward occupied by patients who had tested positive for methicillin-resistant Staphylococcus aureus (MRSA). The QAC being tested is an antibacterial film that is sprayed onto a surface and can remain active for up to 8 h. A field experimental study was designed with the QAC plus daily hypochlorite cleaning as the experimental group and hypochlorite cleaning alone as the control group. The method of swabbing on moistened surfaces was used for sampling. It was found that 83% and 77% of the bedside surfaces of MRSA-positive and MRSA-negative patients respectively were contaminated with staphylococci at 08:00 hours, and that the staphylococcal concentrations increased by 80% at 1200 h over a 4-hour period with routine ward and clinical activities. Irrespective of the MRSA status of the patients, high-touch surfaces around the bed-units within the studied medical ward were heavily contaminated (ranged 1 to 276 cfu/cm2 amongst the sites with positive culture) with staphylococcal bacteria including MRSA, despite the implementation of daily hypochlorite wiping. However, the contamination rate dropped significantly from 78% to 11% after the application of the QAC polymer. In the experimental group, the mean staphylococcal concentration of bedside surfaces was significantly (p < 0.0001) reduced from 4.4 ± 8.7 cfu/cm2 at 08:00 hours to 0.07 ± 0.26 cfu/cm2 at 12:00 hours by the QAC polymer. The results of this study support the view that, in addition to hypochlorite wiping, the tested QAC surfactant is a potential environmental decontamination strategy for preventing the transmission of clinically important pathogens in medical wards. PMID:25768241

  5. Methicillin-resistant Staphylococcus aureus (MRSA) contamination in bedside surfaces of a hospital ward and the potential effectiveness of enhanced disinfection with an antimicrobial polymer surfactant.

    PubMed

    Yuen, John W M; Chung, Terence W K; Loke, Alice Y

    2015-03-01

    The aim in this study was to assess the effectiveness of a quaternary ammonium chloride (QAC) surfactant in reducing surface staphylococcal contamination in a routinely operating medical ward occupied by patients who had tested positive for methicillin-resistant Staphylococcus aureus (MRSA). The QAC being tested is an antibacterial film that is sprayed onto a surface and can remain active for up to 8 h. A field experimental study was designed with the QAC plus daily hypochlorite cleaning as the experimental group and hypochlorite cleaning alone as the control group. The method of swabbing on moistened surfaces was used for sampling. It was found that 83% and 77% of the bedside surfaces of MRSA-positive and MRSA-negative patients respectively were contaminated with staphylococci at 08:00 hours, and that the staphylococcal concentrations increased by 80% at 1200 h over a 4-hour period with routine ward and clinical activities. Irrespective of the MRSA status of the patients, high-touch surfaces around the bed-units within the studied medical ward were heavily contaminated (ranged 1 to 276 cfu/cm2 amongst the sites with positive culture) with staphylococcal bacteria including MRSA, despite the implementation of daily hypochlorite wiping. However, the contamination rate dropped significantly from 78% to 11% after the application of the QAC polymer. In the experimental group, the mean staphylococcal concentration of bedside surfaces was significantly (p<0.0001) reduced from 4.4±8.7 cfu/cm2 at 08:00 hours to 0.07±0.26 cfu/cm2 at 12:00 hours by the QAC polymer. The results of this study support the view that, in addition to hypochlorite wiping, the tested QAC surfactant is a potential environmental decontamination strategy for preventing the transmission of clinically important pathogens in medical wards. PMID:25768241

  6. Anti-methicillin-resistant Staphylococcus aureus (MRSA) activity of MC21-B, an antibacterial compound produced by the marine bacterium Pseudoalteromonas phenolica O-BC30T.

    PubMed

    Isnansetyo, Alim; Kamei, Yuto

    2009-08-01

    The aim of this study was to purify, characterise and evaluate the in vitro activity of MC21-B, an antibiotic produced by the marine bacterium Pseudoalteromonas phenolica O-BC30(T). MC21-B was purified by sequential silica and Cosmosil chromatography followed by high-performance liquid chromatography (HPLC). The chemical structure of MC21-B was determined by ultraviolet, infrared, electron impact mass and nuclear magnetic resonance spectrometric analyses. To evaluate its antibacterial activity, minimum inhibitory concentrations (MICs) against 10 clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) as well as kill times were determined. Antifungal activity was determined by the paper disk diffusion method. Cytotoxicity against human cells was determined with MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide]. Based on spectrophotometric analyses, MC21-B was predicted to be a novel substance, 2,2',3-tribromobiphenyl-4,4'-dicarboxylic acid. MC21-B exhibited anti-MRSA activity against all 10 clinical isolates of MRSA, with MICs between 1 microg/mL and 4 microg/mL. MC21-B was highly active against Bacillus subtilis and Enterococcus serolicida but was inactive against Gram-negative bacteria and fungi. Furthermore, MC21-B exhibited cytotoxic activity against human normal dermal fibroblasts and human leukaemic (MOLT) cells at 3-12-fold higher concentrations than required for its antibacterial activity. These results demonstrated that MC21-B has high in vitro activity against MRSA and might be useful as a lead compound in developing new anti-MRSA substances.

  7. Comprehensive Characterization of Methicillin-resistant Staphylococcus aureus subsp. aureus COL Secretome by Two-dimensional Liquid Chromatography and Mass Spectrometry*

    PubMed Central

    Ravipaty, Shobha; Reilly, James P.

    2010-01-01

    Two-dimensional LC combined with whole protein and peptide mass spectrometry is used to characterize proteins secreted by methicillin-resistant Staphylococcus aureus COL. Protein identifications were accomplished via off-line protein fractionation followed by digestion and subsequent peptide analysis by reverse phase LC-ESI-LTQ-FT-MS/MS. Peptide MS/MS analysis identified 127 proteins comprising 59 secreted proteins, seven cell wall-anchored proteins, four lipoproteins, four membrane proteins, and 53 cytoplasmic proteins. The identified secreted proteins included various virulence factors of known functions (cytotoxins, enterotoxins, proteases, lipolytic enzymes, peptidoglycan hydrolases, etc.). Accurate whole protein mass measurement (±1.5 Da) of the secreted proteins combined with peptide analysis enabled identification of signal peptide cleavage sites and various post-translational modifications. In addition, new observations were possible using the present approach. Although signal peptide cleavage is highly specific, signal peptide processing can occur at more than one site. Surprisingly, cleaved signal peptides and their fragments can be observed in the extracellular medium. The prediction accuracies of several signal peptide prediction programs were also evaluated. PMID:20418541

  8. Mycelium of fungi isolated from mouldy foods inhibits Staphylococcus aureus including MRSA – A rationale for the re-introduction of mycotherapy?

    PubMed Central

    Alnaimat, Sulaiman; Alharbi, Naiyf S.; Alharbi, Sulaiman Ali; Salmen, Saleh H.; Chinnathambi, Arunachalam; Al-Johny, Bassam O.; Wainwright, M.

    2015-01-01

    Fungal mycelium capable of producing antibacterial agents was isolated from samples of apple, beetroot, lemon and orange; the mycelium of all isolates produced penicillin, while the apple and beetroot samples also produced the antibacterial mycotoxin patulin. The known penicillin-producing fungi were shown to produce penicillin, but not patulin. The mycelial discs of all of fruit and vegetable isolates, as well as the two known penicillin producing fungi, inhibited Staphylococcus aureus, and mycelium of all isolates inhibited MRSA, in contrast, only one of the two known penicillin-producers did so. The results are discussed in relation to the possibility of using the mycelium of Penicillium species in mycotherapy. PMID:26288565

  9. General Information about MRSA in the Community

    MedlinePlus

    ... Recommend on Facebook Tweet Share Compartir MRSA is methicillin-resistant Staphylococcus aureus , a type of staph bacteria that is resistant to several antibiotics. In the general community, MRSA most often causes ...

  10. Cost Analysis of Universal Screening vs. Risk Factor-Based Screening for Methicillin-Resistant Staphylococcus aureus (MRSA)

    PubMed Central

    Roth, Virginia R.; Longpre, Tara; Coyle, Doug; Suh, Kathryn N.; Taljaard, Monica; Ramotar, Karamchand; Forster, Alan

    2016-01-01

    Background The literature remains conflicted regarding the most effective way to screen for MRSA. This study was designed to assess costs associated with universal versus risk factor-based screening for the reduction of nosocomial MRSA transmission. Methods The study was conducted at The Ottawa Hospital, a large multi-centre tertiary care facility with approximately 47,000 admissions annually. From January 2006-December 2007, patients underwent risk factor-based screening for MRSA on admission. From January 2008 to August 2009 universal MRSA screening was implemented. A comparison of costs incurred during risk factor-based screening and universal screening was conducted. The model incorporated probabilities relating to the likelihood of being tested and the results of polymerase chain reaction (PCR) testing with associated effects in terms of MRSA bacteremia and true positive and negative test results. Inputted costs included laboratory testing, contact precautions and infection control, private room costs, housekeeping, and length of hospital stay. Deterministic sensitivity analyses were conducted. Results The risk factor-based MRSA screening program screened approximately 30% of admitted patients and cost the hospital over $780 000 annually. The universal screening program screened approximately 83% of admitted patients and cost over $1.94 million dollars, representing an excess cost of $1.16 million per year. The estimated additional cost per patient screened was $17.76. Conclusion This analysis demonstrated that a universal MRSA screening program was costly from a hospital perspective and was previously known to not be clinically effective at reducing MRSA transmission. These results may be useful to inform future model-based economic analyses of MRSA interventions. PMID:27462905

  11. EUREGIO MRSA-net Twente/Münsterland--a Dutch-German cross-border network for the prevention and control of infections caused by methicillin-resistant Staphylococcus aureus.

    PubMed

    Friedrich, A W; Daniels-Haardt, I; Köck, R; Verhoeven, F; Mellmann, A; Harmsen, D; van Gemert-Pijnen, J E; Becker, K; Hendrix, M G R

    2008-08-28

    Methicillin-resistant Staphylococcus aureus (MRSA) is associated with increased mortality and morbidity and a leading cause of hospital-acquired infections. Community-acquired (CA)-MRSA are a growing concern worldwide. In the last 10 years, an increase in the MRSA rate from 2% to approximately 23% has been observed in Germany, while a rate under 5% has been recorded for many years in the Netherlands and Scandinavia. In the Netherlands in particular, MRSA rates have become very low in stationary care due to a consistent 'search and destroy' policy. The main focus in Germany lies on hospital-acquired MRSA, whereas the Netherlands focus on the control of the importation of MRSA cases from abroad and on CA-MRSA. As MRSA in hospitals and in the community can be a problem in cross-border health care, the European Union-funded EUREGIO MRSA-net project was established in the bordering regions Twente/Achterhoek, the Netherlands and Münsterland, Germany. The main aim of the project is the creation of a network of the major health care providers in the EUREGIO and the surveillance and prevention of MRSA infections. A spa-typing network was established in order to understand the regional and cross-border dissemination of epidemic and potentially highly virulent MRSA genotypes. As the reduction of differences in health care quality is an important prerequisite for cross-border health care, a transborder quality group comprising hospitals, general practitioners, public health authorities, laboratories, and insurerance companies has been established since 2005 equalising the quality criteria for the control of MRSA on both sides of the border. PMID:18761882

  12. MRSA nasal colonization burden and risk of MRSA infection

    PubMed Central

    Stenehjem, Edward; Rimland, David

    2013-01-01

    Background Staphylococcus aureus nasal colonization burden has been identified as a risk factor for infection. This study evaluates methicillin-resistant S aureus (MRSA) nasal burden, as defined by the cycle threshold (Ct) and risk of subsequent infection. Methods In a retrospective cohort study, United States veterans were classified into 3 MRSA nasal colonization groups: noncarriers, low burden (Ct > 24 cycles), and high burden (Ct ≤ 24 cycles). MRSA infections were identified prospectively, and clinical information was obtained by chart review. Multivariate logistic regression assessed the association of MRSA nasal burden and risk of MRSA infection. Results During 4-years of follow-up, 4.3% of noncarriers, 18.5% of low burden, and 17.2% of high burden developed a MRSA infection. In multivariate analysis, MRSA nasal colonization was a risk factor for MRSA infection (P = .008) with low burden (risk ratio [RR], 3.62; 95% confidence interval [CI]: 1.47–8.93) and high burden (RR, 2.71; 95% CI: 0.95–7.72) associated with subsequent MRSA infection when compared with noncarriers. When compared with low burden, high burden nasal carriers were not at increased risk of infection (RR, 0.75; 95% CI 0.36–1.55). Conclusion MRSA nasal colonization was a risk factor for MRSA infection. High nasal burden of MRSA did not increase the risk of infection. PMID:23261345

  13. Dissemination of multiple MRSA clones among community-associated methicillin-resistant Staphylococcus aureus infections from Japanese children with impetigo.

    PubMed

    Hisata, Ken; Ito, Teruyo; Matsunaga, Nobuaki; Komatsu, Mitsutaka; Jin, Jingxun; Li, Shanshuang; Watanabe, Shinya; Shimizu, Toshiaki; Hiramatsu, Keiichi

    2011-10-01

    The proportion of MRSA strains that cause skin and soft infections has recently increased. In 3 months we have characterized 17 MRSA strains isolated from children with impetigo at a Japanese hospital. Seventeen MRSA strains belonged to 7 clones defined by clonal complex (CC) in MLST genotype and type of SCCmec, which were rarely identified among healthcare-associated MRSA: CC 91-SCCmecIIb (4 strains); CC91-SCCmecIIn (2 strains); CC91-SCCmecIVa (2 strains); CC91-SCCmecV (4 strains); CC88-SCCmecIVg (3 strains); CC1-SCCmecIVc (1 strain); and CC5-SCCmecIVn (1 strain). Although one strain belonged to CC5, which has been commonly identified in healthcare-associated MRSA, it did not carry type II SCCmec, but carried type IV SCCmec. Fourteen of the 17 strains carried exfoliative toxin a or b gene, and none carried Panton-Valentine leukocidine gene. Furthermore, we determined the entire nucleotide sequences of two type V SCCmec elements carried by strains JCSC5952, a CC91 strain, and TSGH17, a Taiwanese CC59 strain. The structure of SCCmecJCSC5952 was more than 99% homologous in nucleotide identity with those of Taiwanese PVL-positive ST59 MRSA strains TSGH17 and PM1, which were designated as type V (5C2&5). Identification of multiple MRSA clones distinct from those disseminating at the hospital suggests that MRSA strains might be emerging in the community from MSSA strains by acquiring SCCmec elements on various occasions. Carriage of the similar type V(5C2&5) SCCmec element by strains of distinct genetic backgrounds, CC91 and CC59, suggested horizontal transfer of the SCCmec element.

  14. Frequency of biocide-resistant genes and susceptibility to chlorhexidine in high-level mupirocin-resistant, methicillin-resistant Staphylococcus aureus (MuH MRSA).

    PubMed

    Liu, Qingzhong; Zhao, Huanqiang; Han, Lizhong; Shu, Wen; Wu, Qiong; Ni, Yuxing

    2015-08-01

    The aim of this study was to determine the prevalence of biocide-resistant determinants and the susceptibility to chlorhexidine in high-level mupirocin-resistant, methicillin-resistant Staphylococcus aureus (MuH MRSA). Fifty-three MuH MRSA isolates were analyzed for plasmid-borne genes (qacA/B, smr, qacG, qacH, and qacJ) by polymerase chain reaction (PCR); for chromosome-mediated genes (norA, norB, norC, mepA, mdeA, sepA, and sdrM) by PCR and quantitative reverse transcription-PCR (qRT-PCR); and for susceptibility to chlorhexidine by MIC and minimum bactericidal concentration (MBC). Furthermore, disinfectant efficacy was tested in the presence of 3.0% bovine serum albumin (BSA) in MBC detection. The plasmid-borne genes qacA/B (83.0%) and smr (77.4%) and overexpressions of chromosome-mediated genes norA (49.0%) and norB (28.8%) were predominantly found in isolates studied, and 90.6% of the isolates revealed tolerance to chlorhexidine. In the presence of BSA, the average MBC of chlorhexidine for these isolates rose to 256 μg/mL. Altogether, our results suggest that surveillance of sensitivity to biocides among MuH MRSA isolates is essential for hospital infection control.

  15. SPR-DNA array for detection of methicillin-resistant Staphylococcus aureus (MRSA) in combination with loop-mediated isothermal amplification.

    PubMed

    Nawattanapaiboon, Kawin; Kiatpathomchai, Wansika; Santanirand, Pitak; Vongsakulyanon, Apirom; Amarit, Ratthasart; Somboonkaew, Armote; Sutapun, Boonsong; Srikhirin, Toemsak

    2015-12-15

    In this study, we evaluated surface plasmon resonance imaging (SPR imaging) as a DNA biosensor for the detection of methicillin-resistant Staphylococcus aureus (MRSA) which is one of the most common causes of nosocomial infections. The DNA sample were collected from clinical specimens, including sputum and blood hemoculture were undergone LAMP amplification for 0.18 kbp and 0.23 kbp DNA fragments of femB and mecA genes, respectively. The self-assembled monolayer surface (SAMs) was used for immobilized streptavidin-biotinylated probes on the sensor surface for the detection of LAMP amplicons from MRSA. Both LAMP amplicons were simultaneously hybridized with ssDNA probes immobilized onto a bio-functionalized surface to detect specific targets in the multiplex DNA array platform. In addition, the sensor surface could be regenerated allowing at least five cycles of use with a shortened assay time. The detection limit of LAMP-SPR sensing was 10 copies/µl and LAMP-SPR sensing system showed a good selectivity toward the MRSA.

  16. Prevalence, antimicrobial susceptibility and molecular typing of Methicillin-Resistant Staphylococcus aureus (MRSA) in bulk tank milk from southern Italy.

    PubMed

    Parisi, A; Caruso, M; Normanno, G; Latorre, L; Sottili, R; Miccolupo, A; Fraccalvieri, R; Santagada, G

    2016-09-01

    This paper assesses the prevalence of MRSA in bulk tank milk (BTM) samples from southern Italy, and the relationship between the Coagulase Positive Staphylococci count (CPS) and MRSA prevalence. Of 486 BTM samples tested, 12 samples (2.5%) resulted positive for the presence of MRSA. Great genetic diversity was found among the isolates: ST1/t127 and t174/IVa, ST5/t688/V, ST8/t unknown/IVa/V, ST45/t015/IVa, ST71/t524/V, ST88/t786/Iva, ST398/t011 and t899/IVa/V and ST2781/t1730/V. All isolates were pvl-negative and icaA positive. The majority of strains (58%) carried the ses (sec, seh, seg, seo, sem and sen) genes. All tested strains resulted susceptible to amikacin, cephalotin, cloramphenicol, gentamycin, trimethoprim - sulfamethoxazole, tobramycin and vancomycin, and variably resistant to ampicillin, oxacillin and tetracycline. No statistical association between the CPS count and MRSA detection was found in the MRSA-positive samples. Although some of the spa-types and STs detected in our survey are known to cause human infections, raw milk from Italian herds in the considered area is not a common source of MRSA. Nonetheless, it is necessary to assess the risk of foodborne infection and the risk related to the handling of milk.

  17. In vitro activity of beta-lactam antibiotics to community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA).

    PubMed

    Germel, C; Haag, A; Söderquist, B

    2012-04-01

    Community-associated (CA) MRSA often display low MIC values against oxacillin. The in vitro activity of various beta-lactam antibiotics against heterogeneous CA-MRSA (n = 98) isolated in a low endemic area was determined by Etest, and Mueller-Hinton agar (MUHAP) was compared with Mueller-Hinton agar supplemented with 2% NaCl (MUHSP). In general, the CA-MRSA isolates showed higher MIC values for the various beta-lactam antibiotics on MUHSP compared with MUHAP. MIC values for oxacillin ranged from 1 to >256 mg/L on MUHSP. Cephalothin, representing the first generation of cephalosporins, showed MICs from 0.75 to 96 mg/L and the MIC(50) and MIC(90) for cefuroxime, cefotaxime and cefepime, representing the second, third and fourth generations, respectively, were rather high. However, the MIC(50) and MIC(90) for ceftobiprole (fifth generation) were 1.5 and 2 mg/L, respectively, on MUHSP. The MIC(50) and MIC(90) for imipenem were 0.75 and 2 mg/L, respectively, on MUHSP. Only 3/98 (3%) CA-MRSA isolates showed a MIC >4 mg/L. Consequently, low MIC values for imipenem, lower than those of the newly developed fifth generation cephalosporins, were found among CA-MRSA. These findings may be considered for further studies including clinical trials in order to evaluate carbapenems as a potential treatment option for infections caused by CA-MRSA.

  18. Molecular modeling, dynamics studies and virtual screening of Fructose 1, 6 biphosphate aldolase-II in community acquired- methicillin resistant Staphylococcus aureus (CA-MRSA).

    PubMed

    Yadav, Pramod Kumar; Singh, Gurmit; Gautam, Budhayash; Singh, Satendra; Yadav, Madhu; Srivastav, Upasana; Singh, Brijendra

    2013-01-01

    Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) has recently emerged as a nosocomial pathogen to the community which commonly causes skin and soft-tissue infections (SSTIs). This strain (MW2) has now become resistant to the most of the beta-lactam antibiotics; therefore it is the urgent need to identify the novel drug targets. Recently fructose 1,6 biphosphate aldolase-II (FBA) has been identified as potential drug target in CA-MRSA. The FBA catalyses the retro-ketolic cleavage of fructose-1,6-bisphosphate (FBP) to yield dihydroxyacetone phosphate (DHAP) and glyceraldehyde-3-phosphate (G3P) in glycolytic pathway. In the present research work the 3D structure of FBA was predicted using the homology modeling method followed by validation. The molecular dynamics simulation (MDS) of the predicted model was carried out using the 2000 ps time scale and 1000000 steps. The MDS results suggest that the modeled structure is stable. The predicted model of FBA was used for virtual screening against the NCI diversity subset-II ligand databases which contain 1364 compounds. Based on the docking energy scores, it was found that top four ligands i.e. ZINC01690699, ZINC13154304, ZINC29590257 and ZINC29590259 were having lower energy scores which reveal higher binding affinity towards the active site of FBA. These ligands might act as potent inhibitors for the FBA so that the menace of antimicrobial resistance in CA-MRSA can be conquered. However, pharmacological studies are required to confirm the inhibitory activity of these ligands against the FBA in CA-MRSA.

  19. Imidazolidine-4-one derivatives in the search for novel chemosensitizers of Staphylococcus aureus MRSA: synthesis, biological evaluation and molecular modeling studies.

    PubMed

    Matys, Anna; Podlewska, Sabina; Witek, Karolina; Witek, Jagna; Bojarski, Andrzej J; Schabikowski, Jakub; Otrębska-Machaj, Ewa; Latacz, Gniewomir; Szymańska, Ewa; Kieć-Kononowicz, Katarzyna; Molnar, Joseph; Amaral, Leonard; Handzlik, Jadwiga

    2015-08-28

    A series of amine derivatives of 5-aromatic imidazolidine-4-ones (7-19), representing three subgroups: piperazine derivatives of 5-arylideneimidazolones (7-13), piperazine derivatives of 5-arylideneimidazolidine-2,4-dione (14-16) and primary amines of 5-naphthyl-5-methylimidazolidine-2,4-diones (17-19), was evaluated for their ability to improve antibiotics effectiveness in two strains of Gram-positive Staphylococcus aureus: ATCC 25923 (a reference strain) and MRSA (methicillin resistant S. aureus) HEMSA 5 (a resistant clinical isolate). The latter compounds (17-19) were obtained by 4-step synthesis using Bucherer-Bergs condensation, two-phase bromoalkylation and Gabriel reactions. The naphthalen derivative: (Z)-5-(naphthalen-2-ylmethylene)-2-(piperazin-1-yl)-3H-imidazol-4(5H)-one (10) was the most potent in combination with β-lactam antibiotics and ciprofloxacin against the resistant strain. The high potency to increase efficacy of oxacillin was noted for (Z)-5-(anthracen-10-ylmethylene)-2-(piperazin-1-yl)-3H-imidazol-4(5H)one (12) too. In order to explain the mechanism of action of the compounds 10 and 12, docking studies with the use of crystal structures of a penicillin binding protein (PBP2a) and MecR1 were carried out. Their outcomes suggested that the most probable mechanism of action of the active compounds is the interaction with MecR1. Molecular dynamic experiments performed for the active compounds and compound 13 (structurally similar to 12) supported this hypothesis and provided possible explanation of activity dependencies of the tested compounds in terms of the restoration of antibiotic efficacy in S. aureus MRSA HEMSA 5. PMID:26160112

  20. Comparison of the Next-Generation Xpert MRSA/SA BC Assay and the GeneOhm StaphSR Assay to Routine Culture for Identification of Staphylococcus aureus and Methicillin-Resistant S. aureus in Positive-Blood-Culture Broths

    PubMed Central

    Buchan, Blake W.; Allen, Stephen; McElvania TeKippe, Erin; Davis, Thomas; Levi, Michael; Mayne, Donna; Pancholi, Preeti; Relich, Ryan F.; Thomson, Richard

    2014-01-01

    A bloodstream infection with Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA), is a serious condition that carries a high mortality rate and is also associated with significant hospital costs. The rapid and accurate identification and differentiation of methicillin-susceptible S. aureus (MSSA) and MRSA directly from positive blood cultures has demonstrated benefits in both patient outcome and cost-of-care metrics. We compare the next-generation Xpert MRSA/SA BC (Xpert) assay to the GeneOhm StaphSR (GeneOhm) assay for the identification and detection of S. aureus and methicillin resistance in prospectively collected blood culture broths containing Gram-positive cocci. All results were compared to routine bacterial culture as the gold standard. Across 8 collection and test sites, the Xpert assay demonstrated a sensitivity of 99.6% (range, 96.4% to 100%) and a specificity of 99.5% (range, 98.0% to 100%) for identifying S. aureus, as well as a sensitivity of 98.1% (range, 87.5% to 100%) and a specificity of 99.6% (range, 98.3% to 100%) for identifying MRSA. In comparison, the GeneOhm assay demonstrated a sensitivity of 99.2% (range, 95.2% to 100%) and a specificity of 96.5% (range, 89.2% to 100%) for identifying S. aureus, as well as a sensitivity of 94.3% (range, 87.5% to 100%) and a specificity of 97.8% (range, 96.1% to 100%) for identifying MRSA. Five of six cultures falsely reported as negative for MRSA by the GeneOhm assay were correctly identified as positive by the Xpert assay, while one culture falsely reported as negative for MRSA by the Xpert assay was correctly reported as positive by the GeneOhm assay. PMID:25540397

  1. Rapid bench identification of methicillin-sensitive and methicillin-resistant Staphylococcus aureus: A multicenter comparative evaluation of Alere PBP2a Culture Colony Test (Alere) Versus Slidex MRSA detection (bioMérieux).

    PubMed

    Tasse, Jason; Dupieux, Céline; Caillon, Jocelyne; Lanotte, Philippe; Lamy, Brigitte; Aissa, Nejla; Bemer, Pascale; Mereghetti, Laurent; Michon, Anne-Laure; Lozniewski, Alain; Bes, Michèle; Trouillet-Assant, Sophie; Laurent, Frédéric

    2016-08-01

    Using 30 clinical isolates of Staphylococcus aureus representative of the most prevalent clones circulating in France, the performance of the Alere™ PBP2a Culture Colony Test (CCT) and the Slidex(®) MRSA detection kit (SMD) were compared in 5 different labs. CCT demonstrated better performance and was easier to conduct in routine.

  2. Rapid bench identification of methicillin-sensitive and methicillin-resistant Staphylococcus aureus: A multicenter comparative evaluation of Alere PBP2a Culture Colony Test (Alere) Versus Slidex MRSA detection (bioMérieux).

    PubMed

    Tasse, Jason; Dupieux, Céline; Caillon, Jocelyne; Lanotte, Philippe; Lamy, Brigitte; Aissa, Nejla; Bemer, Pascale; Mereghetti, Laurent; Michon, Anne-Laure; Lozniewski, Alain; Bes, Michèle; Trouillet-Assant, Sophie; Laurent, Frédéric

    2016-08-01

    Using 30 clinical isolates of Staphylococcus aureus representative of the most prevalent clones circulating in France, the performance of the Alere™ PBP2a Culture Colony Test (CCT) and the Slidex(®) MRSA detection kit (SMD) were compared in 5 different labs. CCT demonstrated better performance and was easier to conduct in routine. PMID:27216499

  3. Staphylococcus aureus mutants lacking cell wall-bound protein A found in isolates from bacteraemia, MRSA infection and a healthy nasal carrier.

    PubMed

    Sørum, Marit; Sangvik, Maria; Stegger, Marc; Olsen, Renate S; Johannessen, Mona; Skov, Robert; Sollid, Johanna U E

    2013-02-01

    Staphylococcus aureus is a major human pathogen and a multitude of virulence factors enables it to cause infections, from superficial lesions to life-threatening systemic conditions. Staphylococcal protein A (SpA) is a surface protein contributing to S. aureus pathogenesis by interfering with immune responses and activating inflammation. Seven isolates with frameshift mutations in the spa repeat region were investigated to determine whether these mutations lead to truncation and secretion of SpA into the extracellular environment. Five isolates originated from blood cultures, one from an MRSA infection and one from a persistent nasal carrier. Full-length spa genes from the seven isolates were sequenced, and Western blot experiments were performed to localize SpA. Three isolates had identical deviating 25-bp spa repeats, but all isolates displayed different repeat successions. The DNA sequence revealed that the frameshift mutations created premature stop codons in all seven isolates, resulting in truncated SpA of different lengths, however, all lacking the XC region with the C-terminal sorting signal. SpA was detected by Western blot in six of the seven isolates, mainly extracellularly. Our findings demonstrate that S. aureus isolates with truncated SpA, not anchored to the cell wall, can still be found in bacteraemia, infection and among carriers.

  4. The Tipper-Strominger Hypothesis and Triggering of Allostery in Penicillin-Binding Protein 2a of Methicillin-Resistant Staphylococcus aureus (MRSA).

    PubMed

    Fishovitz, Jennifer; Taghizadeh, Negin; Fisher, Jed F; Chang, Mayland; Mobashery, Shahriar

    2015-05-27

    The transpeptidases involved in the synthesis of the bacterial cell wall (also known as penicillin-binding proteins, PBPs) have evolved to bind the acyl-D-Ala-D-Ala segment of the stem peptide of the nascent peptidoglycan for the physiologically important cross-linking of the cell wall. The Tipper-Strominger hypothesis stipulates that β-lactam antibiotics mimic the acyl-D-Ala-D-Ala moiety of the stem and, thus, are recognized by the PBPs with bactericidal consequences. We document that this mimicry exists also at the allosteric site of PBP2a of methicillin-resistant Staphylococcus aureus (MRSA). Interactions of different classes of β-lactam antibiotics, as mimics of the acyl-D-Ala-D-Ala moiety at the allosteric site, lead to a conformational change, across a distance of 60 Å to the active site. We directly visualize this change using an environmentally sensitive fluorescent probe affixed to the protein loops that frame the active site. This conformational mobility, documented in real time, allows antibiotic access to the active site of PBP2a. Furthermore, we document that this allosteric trigger enables synergy between two different β-lactam antibiotics, wherein occupancy at the allosteric site by one facilitates occupancy by a second at the transpeptidase catalytic site, thus lowering the minimal-inhibitory concentration. This synergy has important implications for the mitigation of facile emergence of resistance to these antibiotics by MRSA.

  5. Investigation into the potential of sub-lethal photodynamic antimicrobial chemotherapy (PACT) to reduce susceptibility of meticillin-resistant Staphylococcus aureus (MRSA) to antibiotics

    NASA Astrophysics Data System (ADS)

    Cassidy, C. M.; Donnelly, R. F.; Tunney, M. M.

    2009-06-01

    In PACT, a combination of a sensitising drug and visible light cause the selective destruction of microbial cells via singlet oxygen production. As singlet oxygen is a non-specific oxidizing agent and is only present during illumination, development of resistance to this treatment is thought to be unlikely. However, in response to oxidative stress, bacteria can up-regulate oxidative stress genes and associated antibiotic resistance genes. The up-regulation of these genes and potential transfer of genetic material may result in a resistant bacterial population. This study determined whether treatment of clinically isolated meticillin resistant Staphylococcus aureus (MRSA) strains with sub-lethal doses of methylene blue (MB) and meso-tetra (N-methyl-4-pyridyl) porphine tetra tosylate (TMP)-PACT resulted in reduced susceptibility to antibiotics and previously lethal PACT. Exposure of strains to sub-lethal doses of photosensitizer in combination with light had no effect on susceptibility to previously lethal photosensitization. Furthermore, exposure to sub-lethal concentrations of both photosensitizers caused no significant changes in the minimum inhibitory concentration (MIC) for each strain tested. Any differences in susceptibility were not significant as they did not cross breakpoints between resistant and susceptible for any organism or antibiotic tested. Therefore, PACT remains an attractive alternative option for treatment of MRSA infections.

  6. Concurrent Analysis of Nose and Groin Swab Specimens by the IDI-MRSA PCR Assay Is Comparable to Analysis by Individual-Specimen PCR and Routine Culture Assays for Detection of Colonization by Methicillin-Resistant Staphylococcus aureus

    PubMed Central

    Bishop, Emma J.; Grabsch, Elizabeth A.; Ballard, Susan A.; Mayall, Barrie; Xie, Shirley; Martin, Rhea; Grayson, M. Lindsay

    2006-01-01

    The IDI-MRSA assay (Infectio Diagnostic, Inc., Sainte-Foy, Quebec, Canada) with the Smart Cycler II rapid DNA amplification system (Cepheid, Sunnyvale, CA) appears to be sensitive and specific for the rapid detection of nasal colonization by methicillin-resistant Staphylococcus aureus (MRSA). We assessed the sensitivity and specificity of this assay under conditions in which both the nose and cutaneous groin specimens were analyzed together and compared the accuracy of this PCR approach to that when these specimens were tested separately and by culture assays in an inpatient population with known high rates (12 to 15%) of MRSA colonization. Of 211 patients screened, 192 had results assessable by all three methods (agar-broth culture, separate nose and groin IDI-MRSA assay, and combined nose-groin IDI-MRSA assay), with MRSA carriage noted in 31/192 (16.1%), 41/192 (21.4%), and 36/192 (18.8%) patients by each method, respectively. Compared to agar culture results, the sensitivity and specificity of the combined nose-groin IDI-MRSA assay were 88.0% and 91.6%, respectively, whereas when each specimen was processed separately, the sensitivities were 90.0% (nose) and 83.3% (groin) and the specificities were 91.7% (nose) and 90.2% (groin). IDI-MRSA assay of a combined nose-groin specimen appears to have an accuracy similar to that of the current recommended PCR protocol, providing results in a clinically useful time frame, and may represent a more cost-effective approach to using this assay for screening for MRSA colonization. PMID:16891510

  7. Concurrent analysis of nose and groin swab specimens by the IDI-MRSA PCR assay is comparable to analysis by individual-specimen PCR and routine culture assays for detection of colonization by methicillin-resistant Staphylococcus aureus.

    PubMed

    Bishop, Emma J; Grabsch, Elizabeth A; Ballard, Susan A; Mayall, Barrie; Xie, Shirley; Martin, Rhea; Grayson, M Lindsay

    2006-08-01

    The IDI-MRSA assay (Infectio Diagnostic, Inc., Sainte-Foy, Quebec, Canada) with the Smart Cycler II rapid DNA amplification system (Cepheid, Sunnyvale, CA) appears to be sensitive and specific for the rapid detection of nasal colonization by methicillin-resistant Staphylococcus aureus (MRSA). We assessed the sensitivity and specificity of this assay under conditions in which both the nose and cutaneous groin specimens were analyzed together and compared the accuracy of this PCR approach to that when these specimens were tested separately and by culture assays in an inpatient population with known high rates (12 to 15%) of MRSA colonization. Of 211 patients screened, 192 had results assessable by all three methods (agar-broth culture, separate nose and groin IDI-MRSA assay, and combined nose-groin IDI-MRSA assay), with MRSA carriage noted in 31/192 (16.1%), 41/192 (21.4%), and 36/192 (18.8%) patients by each method, respectively. Compared to agar culture results, the sensitivity and specificity of the combined nose-groin IDI-MRSA assay were 88.0% and 91.6%, respectively, whereas when each specimen was processed separately, the sensitivities were 90.0% (nose) and 83.3% (groin) and the specificities were 91.7% (nose) and 90.2% (groin). IDI-MRSA assay of a combined nose-groin specimen appears to have an accuracy similar to that of the current recommended PCR protocol, providing results in a clinically useful time frame, and may represent a more cost-effective approach to using this assay for screening for MRSA colonization.

  8. Control of an outbreak of methicillin-resistant Staphylococcus aureus (MRSA) by hygienic measures in a general intensive care unit.

    PubMed

    Lingnau, W; Allerberger, F

    1994-01-01

    Infections are a major cause of death in critically ill patients. As gram-positive organisms are more widespread and methicillin-resistant staphylococci (MRSA, MRSE) are easily distributed in overcrowded Intensive Care Units (ICU), extended hygienic procedures for infection control are most important. We hypothesize that strict regulations and educational programs for medical and nursing personnel are able to control the spread of resistant bacteria. In a four-room 16-bed medico-surgical ICU, we reinforced hygienic procedures and introduced the separation of clean postoperative and multiply injured patients from those with infectious complications, subsequent to an outbreak of MRSA in 1991. MRSA and MRSE isolated from surveillance cultures of bronchial secretions were reduced from an annual rate of 60.0% to 37.7% and 36.4% to 6.2% respectively between the years 1991 and 1992. Accordingly, the number of lower respiratory tract infections and the crude mortality could be reduced. We conclude that prompt implementation of control measures and continuous education of medical personnel are able to control an outbreak of infection with resistant staphylococci in an ICU setting.

  9. Prospective Comparison of a New Chromogenic Medium, MRSASelect, to CHROMagar MRSA and Mannitol-Salt Medium Supplemented with Oxacillin or Cefoxitin for Detection of Methicillin-Resistant Staphylococcus aureus

    PubMed Central

    Stoakes, Luba; Reyes, Romina; Daniel, Janis; Lennox, Gwen; John, Michael A.; Lannigan, Robert; Hussain, Zafar

    2006-01-01

    MRSASelect agar was compared to CHROMagar, mannitol-salt agar with oxacillin, and mannitol-salt agar with cefoxitin (MSA-CFOX) for the isolation of methicillin-resistant Staphylococcus aureus (MRSA). The sensitivities and specificities were 97.3% and 99.8%, 82.9% and 99.1%, 80.2% and 79%, and 99.1% and 84.8%, respectively. MSA-CFOX and MRSASelect had a high sensitivity. MRSASelect, however, was more specific and proved to be a more reliable and rapid medium for the detection of MRSA. PMID:16455933

  10. Trends in Staphylococcus aureus bacteraemia and impacts of infection control practices including universal MRSA admission screening in a hospital in Scotland, 2006–2010: retrospective cohort study and time-series intervention analysis

    PubMed Central

    Edwards, Becky; López-Lozano, José-Maria; Gould, Ian

    2012-01-01

    Objectives To describe secular trends in Staphylococcus aureus bacteraemia (SAB) and to assess the impacts of infection control practices, including universal methicillin-resistant Staphylococcus aureus (MRSA) admission screening on associated clinical burdens. Design Retrospective cohort study and multivariate time-series analysis linking microbiology, patient management and health intelligence databases. Setting Teaching hospital in North East Scotland. Participants All patients admitted to Aberdeen Royal Infirmary between 1 January 2006 and 31 December 2010: n=420 452 admissions and 1 430 052 acute occupied bed days (AOBDs). Intervention Universal admission screening programme for MRSA (August 2008) incorporating isolation and decolonisation. Primary and secondary measures Hospital-wide prevalence density, hospital-associated incidence density and death within 30 days of MRSA or methicillin-sensitive Staphylococcus aureus (MSSA) bacteraemia. Results Between 2006 and 2010, prevalence density of all SAB declined by 41%, from 0.73 to 0.50 cases/1000 AOBDs (p=0.002 for trend), and 30-day mortality from 26% to 14% (p=0.013). Significant reductions were observed in MRSA bacteraemia only. Overnight admissions screened for MRSA rose from 43% during selective screening to >90% within 4 months of universal screening. In multivariate time-series analysis (R2 0.45 to 0.68), universal screening was associated with a 19% reduction in prevalence density of MRSA bacteraemia (−0.035, 95% CI −0.049 to −0.021/1000 AOBDs; p<0.001), a 29% fall in hospital-associated incidence density (−0.029, 95% CI −0.035 to −0.023/1000 AOBDs; p<0.001) and a 46% reduction in 30-day mortality (−15.6, 95% CI −24.1% to −7.1%; p<0.001). Positive associations with fluoroquinolone and cephalosporin use suggested that antibiotic stewardship reduced prevalence density of MRSA bacteraemia by 0.027 (95% CI 0.015 to 0.039)/1000 AOBDs. Rates of MSSA bacteraemia were not

  11. Structure of ThiM from Vitamin B1 biosynthetic pathway of Staphylococcus aureus – Insights into a novel pro-drug approach addressing MRSA infections

    PubMed Central

    Drebes, Julia; Künz, Madeleine; Windshügel, Björn; Kikhney, Alexey G.; Müller, Ingrid B.; Eberle, Raphael J.; Oberthür, Dominik; Cang, Huaixing; Svergun, Dmitri I.; Perbandt, Markus; Betzel, Christian; Wrenger, Carsten

    2016-01-01

    Infections caused by the methicillin-resistant Staphylococcus aureus (MRSA) are today known to be a substantial threat for global health. Emerging multi-drug resistant bacteria have created a substantial need to identify and discover new drug targets and to develop novel strategies to treat bacterial infections. A promising and so far untapped antibiotic target is the biosynthesis of vitamin B1 (thiamin). Thiamin in its activated form, thiamin pyrophosphate, is an essential co-factor for all organisms. Therefore, thiamin analogous compounds, when introduced into the vitamin B1 biosynthetic pathway and further converted into non-functional co-factors by the bacterium can function as pro-drugs which thus block various co-factor dependent pathways. We characterized one of the key enzymes within the S. aureus vitamin B1 biosynthetic pathway, 5-(hydroxyethyl)-4-methylthiazole kinase (SaThiM; EC 2.7.1.50), a potential target for pro-drug compounds and analyzed the native structure of SaThiM and complexes with the natural substrate 5-(hydroxyethyl)-4-methylthiazole (THZ) and two selected substrate analogues. PMID:26960569

  12. Structure of ThiM from Vitamin B1 biosynthetic pathway of Staphylococcus aureus – Insights into a novel pro-drug approach addressing MRSA infections

    NASA Astrophysics Data System (ADS)

    Drebes, Julia; Künz, Madeleine; Windshügel, Björn; Kikhney, Alexey G.; Müller, Ingrid B.; Eberle, Raphael J.; Oberthür, Dominik; Cang, Huaixing; Svergun, Dmitri I.; Perbandt, Markus; Betzel, Christian; Wrenger, Carsten

    2016-03-01

    Infections caused by the methicillin-resistant Staphylococcus aureus (MRSA) are today known to be a substantial threat for global health. Emerging multi-drug resistant bacteria have created a substantial need to identify and discover new drug targets and to develop novel strategies to treat bacterial infections. A promising and so far untapped antibiotic target is the biosynthesis of vitamin B1 (thiamin). Thiamin in its activated form, thiamin pyrophosphate, is an essential co-factor for all organisms. Therefore, thiamin analogous compounds, when introduced into the vitamin B1 biosynthetic pathway and further converted into non-functional co-factors by the bacterium can function as pro-drugs which thus block various co-factor dependent pathways. We characterized one of the key enzymes within the S. aureus vitamin B1 biosynthetic pathway, 5-(hydroxyethyl)-4-methylthiazole kinase (SaThiM; EC 2.7.1.50), a potential target for pro-drug compounds and analyzed the native structure of SaThiM and complexes with the natural substrate 5-(hydroxyethyl)-4-methylthiazole (THZ) and two selected substrate analogues.

  13. Performance of a New Chromogenic Medium, BBL CHROMagar MRSA II (BD), for Detection of Methicillin-Resistant Staphylococcus aureus in Screening Samples ▿

    PubMed Central

    Van Vaerenbergh, Kristien; Cartuyvels, Reinoud; Coppens, Guy; Frans, Johan; Van den Abeele, Anne-Marie; De Beenhouwer, Hans

    2010-01-01

    Two chromogenic media for the detection of MRSA were compared: BBL CHROMagar MRSA II (BD) and MRSA ID agar (bioMérieux). Following overnight nonselective enrichment, 1,919 screening samples were inoculated on both chromogenic agars. After 24 h, the sensitivities of both media were high and comparable. Both media showed an important decrease in specificity after 48 h of incubation (decreases of 8% for MRSA II and 10% for MRSA ID), but MRSA II was significantly more specific at both time points. PMID:20181915

  14. Characterization of the staphylococcal cassette chromosome mec insertion site in 108 isolates lacking the mecA gene and identified as methicillin-resistant Staphylococcus aureus by the Xpert MRSA assay.

    PubMed

    Stojanov, M; Blanc, D S

    2014-11-01

    During a 3-year period, 848 patients were detected as carriers of methicillin-resistant Staphylococcus aureus (MRSA) by the Xpert MRSA assay (Cepheid). Among them, 108 patients (12.7 %) were colonized with strains showing methicillin-susceptible phenotypes and absence of the mecA gene, despite being positive with the rapid polymerase chain reaction (PCR) assay. DNA sequences of the staphylococcal cassette chromosome mec (SCCmec) insertion site of these "false-positive" strains was determined by direct sequencing of the genomic DNA. More than half (53.7 %) of the strains had DNA sequences unrelated to either SCC or SCCmec and one-third had DNA sequences related to non-mec SCC. Only 10.2 % of the strains carried sequences related to SCCmec, suggesting that a sequence containing the mecA gene was lost from an SCCmec. These findings differ from the general idea that all methicillin-susceptible S. aureus having positive Xpert MRSA assay results are essentially MRSA that lost the mecA gene.

  15. CA-MRSA. The new sports pathogen.

    PubMed

    Kurkowski, Christina

    2007-01-01

    Skin infections in athletes caused by community-associated Methicillin-resistant Staphylococcus aureus (CA-MRSA) have been observed within many cities throughout the United States and within many countries throughout the world (Centers for Disease Control and Prevention [CDC], 2003). As the incidence rises in the athletic population, clinicians must learn to identify risk factors for CA-MRSA, diagnosis and treat infections with judicious use of antimicrobial agents and facilitate strategies to limit transmission. Recently, a new consensus guideline for handling CA-MRSA outbreaks in sports has been released by the CDC (Gorwitz et al., 2006). This article includes a review of the evolution of MRSA; distinguishes between healthcare associated Methicillin-resistant Staphylococcus aureus (HA-MRSA) and CA-MRSA; and reviews the diagnosis, management, and prevention strategies to limit transmission of CA-MRSA.

  16. Mutations in mmpL and in the cell wall stress stimulon contribute to resistance to oxadiazole antibiotics in methicillin-resistant Staphylococcus aureus.

    PubMed

    Xiao, Qiaobin; Vakulenko, Sergei; Chang, Mayland; Mobashery, Shahriar

    2014-10-01

    Staphylococcus aureus is a leading cause of hospital- and community-acquired infections, which exhibit broad resistance to various antibiotics. We recently disclosed the discovery of the oxadiazole class of antibiotics, which has in vitro and in vivo activities against methicillin-resistant S. aureus (MRSA). We report herein that MmpL, a putative member of the resistance, nodulation, and cell division (RND) family of proteins, contributes to oxadiazole resistance in the S. aureus strain COL. Through serial passages, we generated two S. aureus COL variants that showed diminished susceptibilities to an oxadiazole antibiotic. The MICs for the oxadiazole against one strain (designated S. aureus COL(I)) increased reproducibly 2-fold (to 4 μg/ml), while against the other strain (S. aureus COL(R)), they increased >4-fold (to >8 μg/ml, the limit of solubility). The COL(R) strain was derived from the COL(I) strain. Whole-genome sequencing revealed 31 mutations in S. aureus COL(R), of which 29 were shared with COL(I). Consistent with our previous finding that oxadiazole antibiotics inhibit cell wall biosynthesis, we found 13 mutations that occurred either in structural genes or in promoters of the genes of the cell wall stress stimulon. Two unique mutations in S. aureus COL(R) were substitutions in two genes that encode the putative thioredoxin (SACOL1794) and MmpL (SACOL2566). A role for mmpL in resistance to oxadiazoles was discerned from gene deletion and complementation experiments. To our knowledge, this is the first report that a cell wall-acting antibiotic selects for mutations in the cell wall stress stimulon and the first to implicate MmpL in resistance to antibiotics in S. aureus.

  17. Occupational acquisition of methicillin-resistant Staphylococcus aureus in humans--a description of MRSA carrier and infected cases from the Region of North Jutland in Denmark.

    PubMed

    Omland, Øyvind; Hoffmann, Leif

    2012-01-01

    Since 2006 in Denmark, there has been a statutory order on physicians' notification of methicillin-resistant Staphylococcus aureus (MRSA). Occupational cases notified in North Denmark Region in 2008 and 2009 were analysed. Overall, 109 cases (54 females and 55 males) were notified, of whom 56 were infected and 52 cases were carriers, whereas in one case the status was unknown. The most prevalent clonal complex (CC) was 398 (n=26; 23.9%), followed by CC5 (n=17; 15.6%), CC30 (n=14; 12.8%), and CC8 (n=12; 11%). Eighteen cases were occupational with a predominance of CC398 (n= 16; 88.8%); CC8 and CC22 accounted for one case each. There was a significantly higher proportion of occupational cases for CC398 compared with other clonal complexes (p<0.001). All CC398 occupational cases were either farmers or farm workers occupied in swine confinement buildings. The two other cases were nurses working in the region's public hospitals. Most occupational cases were carriers (n=15; 83%). Three were infected, two with impetigo and one with tonsillitis; CC398 was the causative agent in all three cases. CC398 has a porcine reservoir which is huge in Denmark with a total annual production of 27,700,000 pigs. The presented population-based retrospective study shows an infectious potential of CC398 in humans. Close monitoring of future trends in prevalence, occupational distribution and pathogenicity is still warranted. PMID:23311780

  18. Synthesis, characterization, and evaluation of antibacterial effect of Ag nanoparticles against Escherichia coli O157:H7 and methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Paredes, Daissy; Ortiz, Claudia; Torres, Rodrigo

    2014-01-01

    Silver nanoparticles (AgNPs) have been shown great interest because of their potential antibacterial effect. Recently, this has been increased due to resistance in some pathogenic bacteria strains to conventional antibiotics, which has initiated new studies to search for more effective treatments against resistant microorganisms. For these reasons, AgNPs have become an important approach for applications in nanobiotechnology in the development of antibiotic treatment of different bacterial infections. This study was aimed at synthesizing AgNPs using cysteine as a reducer agent and cetyl-tri-methyl-ammonium bromide as a stabilizer in order to obtain more efficient treatment against the pathogen bacteria Escherichia coli O157:H7. These AgNPs were characterized through UV-Vis spectroscopy, transmission electron microscopy, and dynamic light scattering. From these analyses, formation of spherical nanoparticles with an average size of 55 nm was confirmed. Finally, minimal inhibitory concentration (MIC) and minimal bactericide concentration (MBC) of these AgNPs against pathogenic strains E. coli O157:H7 and methicillin-resistant Staphylococcus aureus (MRSA) were determined in both solid and liquid media. MIC and MBC values were around 0.25 μg/mL and 1 μg/mL, respectively. These parameters were comparable to those reported in the literature and were even more effective than other synthesized AgNPs.

  19. Synthesis, characterization, and evaluation of antibacterial effect of Ag nanoparticles against Escherichia coli O157:H7 and methicillin-resistant Staphylococcus aureus (MRSA)

    PubMed Central

    Paredes, Daissy; Ortiz, Claudia; Torres, Rodrigo

    2014-01-01

    Silver nanoparticles (AgNPs) have been shown great interest because of their potential antibacterial effect. Recently, this has been increased due to resistance in some pathogenic bacteria strains to conventional antibiotics, which has initiated new studies to search for more effective treatments against resistant microorganisms. For these reasons, AgNPs have become an important approach for applications in nanobiotechnology in the development of antibiotic treatment of different bacterial infections. This study was aimed at synthesizing AgNPs using cysteine as a reducer agent and cetyl-tri-methyl-ammonium bromide as a stabilizer in order to obtain more efficient treatment against the pathogen bacteria Escherichia coli O157:H7. These AgNPs were characterized through UV-Vis spectroscopy, transmission electron microscopy, and dynamic light scattering. From these analyses, formation of spherical nanoparticles with an average size of 55 nm was confirmed. Finally, minimal inhibitory concentration (MIC) and minimal bactericide concentration (MBC) of these AgNPs against pathogenic strains E. coli O157:H7 and methicillin-resistant Staphylococcus aureus (MRSA) were determined in both solid and liquid media. MIC and MBC values were around 0.25 μg/mL and 1 μg/mL, respectively. These parameters were comparable to those reported in the literature and were even more effective than other synthesized AgNPs. PMID:24729707

  20. Defining the Active Fraction of Daptomycin against Methicillin-Resistant Staphylococcus aureus (MRSA) Using a Pharmacokinetic and Pharmacodynamic Approach

    PubMed Central

    Garonzik, Samira M.; Lenhard, Justin R.; Forrest, Alan; Holden, Patricia N.; Bulitta, Jϋrgen B.; Tsuji, Brian T.

    2016-01-01

    Our objective was to study the pharmacodynamics of daptomycin in the presence of varying concentrations of human serum (HS) in vitro to quantify the fraction of daptomycin that is ‘active’. Time kill experiments were performed with daptomycin (0 to 256 mg/L) against two MRSA strains at log-phase growth, in the presence of HS (0%, 10%, 30%, 50%, 70%) combined with Mueller-Hinton broth. Daptomycin ≥ 2 mg/L achieved 99.9% kill within 8 h at all HS concentrations; early killing activity was slightly attenuated at higher HS concentrations. After 1 h, bacterial reduction of USA300 upon exposure to daptomycin 4 mg/L ranged from -3.1 to -0.5 log10CFU/mL in the presence of 0% to 70% HS, respectively. Bactericidal activity was achieved against both strains at daptomycin ≥ 4 mg/L for all fractions of HS exposure. A mechanism-based mathematical model (MBM) was developed to estimate the active daptomycin fraction at each %HS, comprising 3 bacterial subpopulations differing in daptomycin susceptibility. Time-kill data were fit with this MBM with excellent precision (r2 >0.95). The active fraction of daptomycin was estimated to range from 34.6% to 25.2% at HS fractions of 10% to 70%, respectively. Despite the reported low unbound fraction of daptomycin, the impact of protein binding on the activity of daptomycin was modest. The active fraction approach can be utilized to design in vitro experiments and to optimize therapeutic regimens of daptomycin in humans. PMID:27284923

  1. Orbital cellulitis with periorbital abscess secondary to methicillin-resistant Staphylococcus aureus (MRSA) sepsis in an immunocompetent neonate.

    PubMed

    Rao, Lavanya G; Rao, Krishna; Bhandary, Sulatha; Shetty, Priyanka Ranjan

    2015-01-01

    This article advocates the need for early incision and drainage of periorbital abscesses. We report a case of a 1.5-month-old neonate with orbital cellulitis and periorbital abscess, which had rapidly developed over a period of 3 days. Treatment history revealed methicillin-resistant Staphylococcus aureus sepsis treated with intravenous vancomycin, and incision and drainage of abscesses at multiple sites (left parotid region, upper and lower limbs). A small swelling noted on the left temporal region on discharge from the hospital was treated with oral cotrimoxazole. However, it spread rapidly to involve the periorbital tissue and the bones of the orbital walls to form a periorbital abscess and orbital cellulitis. PMID:25899513

  2. Comparative analysis of the virulence characteristics of epidemic methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from Chinese children: ST59 MRSA highly expresses core gene-encoded toxin.

    PubMed

    Li, Shipeng; Sun, Jing; Zhang, Jianzhong; Li, Xiangmei; Tao, Xiaoxia; Wang, Lijuan; Sun, Mingjiao; Liu, Yingchao; Li, Juan; Qiao, Yanhong; Yu, Sangjie; Yao, Kaihu; Yang, Yonghong; Shen, Xuzhuang

    2014-02-01

    This study aims to investigate the prevalence of a novel cell wall-anchored protein gene, sasX, and to obtain information on the genetic basis for the pathogenic potential of the MRSA strains isolated from Chinese children. The molecular and virulence characteristics of the clinical strains were analyzed. Twenty-two sequence types (STs) were obtained, with six epidemic clones ST59, ST239, ST1, ST910, ST88, and ST338 accounting for 35.8, 22, 6.6, 6.6, 5.3, and 4.1% respectively. The expression levels of hla, psmα, and RNAIII were higher in ST59 than in other STs (p < 0.05). The sasX gene was detected in 26 (10.7%) MRSA isolates. ST239-MRSA-SCCmecIII-t037 (61.5%) was the predominant sasX-positive MRSA clone. The expressions of PSMα and RNAIII were higher in sasX-positive ST239 isolates than in sasX-negative ST239 ones (p < 0.01). Notably, the percentage of invasive infection in infections caused by sasX-positive ST239 MRSA was higher than that by sasX-negative ST239 MRSA (p = 0.008). This study indicated that ST59 was the predominant clone in the MRSA isolates obtained from Chinese children and might have stronger pathogenic potential. The prevalence of the sasX gene in the MRSA isolates from children was relatively low. Furthermore, the sasX gene might be related to the expressions of PSMα and RNAIII and infection invasiveness.

  3. The Methicillin-resistant Staphylococcus aureus (MRSA) Nasal Real-time PCR: A Predictive Tool for Contamination of the Hospital Environment

    PubMed Central

    Livorsi, DJ; Arif, S; Garry, P; Kundu, MG; Satola, SW; Davis, TH; Batteiger, B; Kressel, AB

    2016-01-01

    Introduction We sought to determine whether the bacterial burden in the nares, as determined by the cycle threshold (CT) value from real-time MRSA PCR, is predictive of environmental contamination with MRSA. Methods Patients identified as MRSA nasal carriers per hospital protocol were enrolled within 72 hours of room admission. Patients were excluded if 1) nasal mupirocin or chlorhexidine body-wash was used within the past month or 2) an active MRSA infection was suspected. Four environmental sites, 6 body sites and a wound, if present, were cultured with pre-moistened swabs. All nasal swabs were submitted for both a quantitative culture and real-time PCR (Roche Lightcycler, Indianapolis, IN). Results 82 patients had a positive MRSA-PCR at study enrollment. There was a negative correlation of moderate strength between the CT value and the number of MRSA colonies in the nares (r= −0.61, p<0.01). Current antibiotic use was associated with lower levels of MRSA nasal colonization (CT value: 30.2 vs. 27.7, p<0.01). Patients who had concomitant environmental contamination had higher median log MRSA nares count (3.9 vs. 2.5, p=0.01) and lower CT values (28.0 vs. 30.2, p<0.01). However, a ROC curve was unable to identify a threshold MRSA nares count that reliably excluded environmental contamination. Conclusions Patients with a higher burden of MRSA in their nares, based on the CT value, were more likely to contaminate their environment with MRSA. However, contamination of the environment cannot be predicted solely by the degree of MRSA nasal colonization. PMID:25627759

  4. High prevalence of methicillin-resistant Staphylococcus aureus (MRSA) carrying the mecC gene in a semi-extensive red deer (Cervus elaphus hispanicus) farm in Southern Spain.

    PubMed

    Gómez, Paula; Lozano, Carmen; González-Barrio, David; Zarazaga, Myriam; Ruiz-Fons, Francisco; Torres, Carmen

    2015-06-12

    The objective was to determine the prevalence of Staphylococcus aureus nasal carriage in red deer of a semi-extensive farm and in humans in contact with the estate animals, and to characterize obtained isolates. Nasal swabs of 65 deer and 15 humans were seeded on mannitol-salt-agar and oxacillin-resistance-screening-agar-base. Isolates were identified by microbiological and molecular methods. Antimicrobial susceptibility profile was determined for 16 antibiotics by disk-diffusion and the presence of eight antibiotic resistance genes, seven virulence genes and genes of immune-evasion-cluster (IEC) was analyzed by PCR. S. aureus was typed by PFGE-SmaI, spa, agr, SCCmec and MLST. Isolates were detected in 16 deer (24.6%). Eleven S. aureus isolates were methicillin-resistant (MRSA), and five were methicillin-susceptible (MSSA). All MRSA harbored mecC gene and were agr-III/SCCmecXI/ST1945 (four spa-t843 and seven spa-t1535). All mecC-MRSA carried blaZ-SCCmecXI and etd2, were IEC-type-E, and belonged to the same PFGE pattern. The five MSSA were typed as spa-t2420/agr-I/ST133. Regarding humans, S. aureus was recovered from six samples (40%). The isolates were MSSA and were typed as spa-t002/agr-II, spa-t012/agr-III or spa-t822/agr-III and showed different IEC types (A, B, D and F). blaZ and erm(A) genes were detected, as well as cna and tst genes. As conclusion, red deer analyzed in this study are frequent carriers of mecC-MRSA CC130 (16.9%), they are characterized by few resistance and virulence determinants, and by the presence of IEC type-E. Deer could be a source of mecC-MRSA which could potentially be transmitted to other animals, or even to humans.

  5. High prevalence of methicillin-resistant Staphylococcus aureus (MRSA) carrying the mecC gene in a semi-extensive red deer (Cervus elaphus hispanicus) farm in Southern Spain.

    PubMed

    Gómez, Paula; Lozano, Carmen; González-Barrio, David; Zarazaga, Myriam; Ruiz-Fons, Francisco; Torres, Carmen

    2015-06-12

    The objective was to determine the prevalence of Staphylococcus aureus nasal carriage in red deer of a semi-extensive farm and in humans in contact with the estate animals, and to characterize obtained isolates. Nasal swabs of 65 deer and 15 humans were seeded on mannitol-salt-agar and oxacillin-resistance-screening-agar-base. Isolates were identified by microbiological and molecular methods. Antimicrobial susceptibility profile was determined for 16 antibiotics by disk-diffusion and the presence of eight antibiotic resistance genes, seven virulence genes and genes of immune-evasion-cluster (IEC) was analyzed by PCR. S. aureus was typed by PFGE-SmaI, spa, agr, SCCmec and MLST. Isolates were detected in 16 deer (24.6%). Eleven S. aureus isolates were methicillin-resistant (MRSA), and five were methicillin-susceptible (MSSA). All MRSA harbored mecC gene and were agr-III/SCCmecXI/ST1945 (four spa-t843 and seven spa-t1535). All mecC-MRSA carried blaZ-SCCmecXI and etd2, were IEC-type-E, and belonged to the same PFGE pattern. The five MSSA were typed as spa-t2420/agr-I/ST133. Regarding humans, S. aureus was recovered from six samples (40%). The isolates were MSSA and were typed as spa-t002/agr-II, spa-t012/agr-III or spa-t822/agr-III and showed different IEC types (A, B, D and F). blaZ and erm(A) genes were detected, as well as cna and tst genes. As conclusion, red deer analyzed in this study are frequent carriers of mecC-MRSA CC130 (16.9%), they are characterized by few resistance and virulence determinants, and by the presence of IEC type-E. Deer could be a source of mecC-MRSA which could potentially be transmitted to other animals, or even to humans. PMID:25912021

  6. General Information about MRSA in Healthcare Settings

    MedlinePlus

    ... infections can cause sepsis and death. MRSA is methicillin-resistant Staphylococcus aureus , a type of staph bacteria that is resistant to many antibiotics. In a healthcare setting, such as a hospital ...

  7. Swine MRSA isolates form robust biofilms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Methicillin-resistant Staphylococcus aureus (MRSA) colonization of livestock animals is common and prevalence rates for pigs have been reported to be as high as 49%. Measures to prevent, control, or eliminate MRSA in swine is of considerable public health concern. Bacterial colonization ...

  8. Swine MRSA isolates form robust biofilms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methicillin-resistant Staphylococcus aureus (MRSA) colonization of livestock animals is common and prevalence rates for pigs have been reported to be as high as 49%. Measures to prevent, control, or eliminate MRSA in swine is of considerable public health concern. Bacterial colonization of both biol...

  9. MRSA - Multiple Languages: MedlinePlus

    MedlinePlus

    ... الذهبية المقاومة للمثيسيلين - العربية Bilingual PDF Health Information Translations Bosnian (Bosanski) MRSA (Methicillin Resistant Staphylococcus Aureus) MRSA ( ...

  10. High Resolution Melting-Typing (HRMT) of methicillin-resistant Staphylococcus aureus (MRSA): The new frontier to replace multi-locus sequence typing (MLST) for epidemiological surveillance studies.

    PubMed

    Mongelli, Gino; Bongiorno, Dafne; Agosta, Marilena; Benvenuto, Sabrina; Stefani, Stefania; Campanile, Floriana

    2015-10-01

    We report an implemented molecular-typing-method based on HRMA to detect SNPs within MLST loci, characterizing 100 clinical MRSA and 11 control strains, representative of Italian clones. The results provide solid evidence that HRMT could be a fast, cost-effective and reliable alternative to MLST, for MRSA molecular epidemiology.

  11. [Outbreak of methicillin-resistant Staphylococcus aureus (MRSA) infection or colonization among patients with neoplastic disease: a clinico-epidemiological study of 11 cases].

    PubMed

    Sakai, C; Satoh, Y; Ohkusu, K; Kumagai, K; Ishii, A

    2001-11-01

    MRSA infection or colonization developed in eleven patients with neoplastic disease including malignant lymphoma (5 cases), soft tissue sarcoma (2 cases), acute myeloblastic leukemia (one), myelodysplastic syndrome (one), multiple myeloma (one), and mesothelioma (one) at our ward from October to December 1999. The infections were pneumonia (six cases), enteritis (three), bacteremia (one), and wound infection (one). Ten of 11 cases received antimicrobial agent (s) during one month before isolation of MRSA, suggesting selection of MRSA. Five cases improved and survived, but six cases died of infection. At the isolation of MRSA, the neutrophil count (NC) of the alive cases was 1, 500/microliter or more but the NC of five cases who died was less than 1,000/microliter, especially less than 100/microliter in three cases who had just received a cancer chemotherapy. Pulsed-field gel electrophoresis, performed in 9 cases, showed an identical DNA-pattern of MRSA in 7 cases, indicating a nosocomial infection. Our method to prevent spread of MRSA targeting solely the patients with MRSA infection was obviously unsatisfactory. We should target also the cases of MRSA colonization and make an effort to wash hands more vigorously. Furthermore, radical reformation such as increasing single sick-rooms drastically and increasing the number of nursing staff is also required.

  12. PS2-36: Population-based Evaluation of Patients with Methicillin-resistant Staphylococcus aureus (MRSA) Infection in Relation to Animal Feeding Operations in Pennsylvania

    PubMed Central

    Schwartz, Brian; Pollak, Jonathan; Mercer, Dione; DeWalle, Joseph; Stewart, Walter

    2011-01-01

    Background/Aims New MRSA strains and epidemiologic patterns of infection have emerged in the past decade, with community-associated patterns now dominant. In Europe, these new community strains have been linked to animal feeding operations (AFOs), raising concerns about the widespread use of non-therapeutic antibiotics in animal feeds. No prior population-based studies have evaluated the risk of MRSA infection in relation to AFOs in the U.S. Methods We used Geisinger Clinic electronic health record data from 2001 to February 2010 on all primary care patients (n = 440,000). Three groups of patients were identified using specific ICD-9 codes: Community-onset MRSA (CO-MRSA) without risk factors (i.e., infection diagnosed as an outpatient, no antibiotics or hospitalizations in the prior year, no household contacts, no history of MRSA colonization); Hospital-onset MRSA (HO-MRSA) with risk factors (i.e., diagnosed in the hospital with at least one MRSA risk factor); and Skin infection (e.g., cellulitis, carbuncle, skin abscess) without MRSA infection or colonization history and without MRSA risk factors. MRSA cases were frequency-matched to controls with no history of MRSA or risk factors. Information on concentrated animal feeding operations (CAFOs) were obtained from the Pennsylvania Department of Environmental Protection, and included data on animal species (e.g., swine, dairy cattle, chickens), counts, animal equivalent units (AEUs), farm acreage, and manure generated, exported, and stored. Measures of density (e.g., AEUs per sq. mi. in township) and accessibility (e.g., distance from residence to nearest CAFO, gravity models) were derived and used in logistic regression models comparing the four groups. Results A total of 1926 MRSA cases were identified from 2003 to 2010. Of these, 1058 (55%) were identified in outpatient records, 530 (28%) from inpatient records, and 290 (15%) from medication orders. Inpatient cases increased from 2 in 2003 to 88 in 2005, remained

  13. [Nosocomial infections with methicillin-resistant Staphylococcus aureus (MRSA) and epidermidis (MRSE) strains. Their importance, prophylaxis and therapy in orthopedic surgery].

    PubMed

    König, D P; Randerath, O; Hackenbroch, M H

    1999-04-01

    MRSA/MRSE infections are a major problem in hospitals and although in orthopaedic units the incidence is low awareness of this problem is necessary. Once a MRSA strain has been isolated the strict use of the hygiene precautions has to be applied to avoid epidemic spread of the strain. The patient has to be isolated. The staff has to use gloves and gowns whilst treating the patient. A antimicrobiel hand wash solution has to be used after taking off the gloves and before leaving the isolation room. Patient and staff have to be informed about the pathogenicity and the way of infection spread so that infection precaution rules are fulfilled. Antibiotics should only be used in clinically well defined cases and the overall use of antibiotics should be reduced to lower the incidence of MRSA/E isolates. The problems of an MRSA case and its successful treatment are demonstrated.

  14. [Molecular epidemiology of the Methicillin-resistant Staphylococcus aureus(MRSA) by the internal transcribed spacer PCR (ITS-PCR) method and the phage open reading frame typing (POT) method].

    PubMed

    Senda, Yasuko; Takemori, Yukiko; Iwata, Yasunori; Fujita, Shinichi; Sakai, Yoshio; Wada, Takashi

    2014-05-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is the most common causative bacteria of hospital acquired infection, and should be rapidly identified for infection control. For this purpose, in our hospital, the PCR electrophoresis patterns of spacer regions (ITS: internal transcribed spacers) (ITS-PCR) are combined with a toxigenicity assay to establish a strain identification method for outbreak surveillance. In the present study, the usefulness of this method was evaluated in comparison with the POT (phage-open reading frame typing) method. One hundred MRSA strains isolated from inpatients in our hospital between April 2011 and March 2012 were classified into 25 patterns using the ITS-PCR method combined with a toxigenicity assay. The strains could be classified into 46 patterns using the POT method. ITS-PCR type 22 strain producing enterotoxin C and toxic shock syndrome toxin-1 could be further classified into 7 patterns using the POT method. In the outbreak of the type 22 strain, cross-infection could be excluded by additional analysis using the POT method, providing more precise information on strain identification. We identified that some strains of the same POT type consisted of different ITS-PCR types or toxigenicities. Therefore, these results suggest that the combination of ITS-PCR method plus toxigenicity assay with POT method may be a useful technique of MRSA typing.

  15. Is methicillin-resistant Staphylococcus aureus replacing methicillin-susceptible S. aureus?

    PubMed Central

    Mostofsky, Elizabeth; Lipsitch, Marc; Regev-Yochay, Gili

    2011-01-01

    Despite extensive research on the emergence of and treatments for methicillin-resistant Staphylococcus aureus (MRSA), prior studies have not rigorously evaluated the impact of methicillin resistance on the overall incidence of S. aureus infections. Yet, there are direct clinical and research implications of determining whether methicillin-susceptible S. aureus (MSSA) infection rates remain stable in the face of increasing MRSA prevalence or whether MSSA will be replaced over time. A synthesis of prior studies indicates that the emergence of healthcare-associated MRSA (HA-MRSA) and community-associated MRSA (CA-MRSA) has led to an increase in the overall incidence of S. aureus infections, with MRSA principally adding to, rather than replacing, MSSA. However, colonization with CA-MRSA may at least partially replace colonization with MSSA. So far, evidence indicates that MSSA still accounts for many infections. Therefore, eradication of MRSA alone is not sufficient to address the public health burden of S. aureus. PMID:21737459

  16. Low level laser therapy (AlGaInP) applied at 5J/cm2 reduces the proliferation of Staphylococcus aureus MRSA in infected wounds and intact skin of rats*

    PubMed Central

    Silva, Daniela Conceição Gomes Gonçalves e; Plapler, Helio; da Costa, Mateus Matiuzzi; Silva, Silvio Romero Gonçalves e; de Sá, Maria da Conceição Aquino; Silva, Benedito Sávio Lima e

    2013-01-01

    BACKGROUND Laser therapy is a low cost, non-invasive procedure with good healing results. Doubts exist as to whether laser therapy action on microorganisms can justify research aimed at investigating its possible effects on bacteria-infected wounds. OBJECTIVE To assess the effect of low intensity laser on the rate of bacterial contamination in infected wounds in the skin of rats. METHODS An experimental study using 56 male Wistar rats. The animals were randomly divided into eight groups of seven each. Those in the "infected" groups were infected by Staphylococcus aureus MRSA in the dorsal region. Red laser diode (AlGaInP) 658nm, 5J/cm2 was used to treat the animals in the "treated" groups in scan for 3 consecutive days. Samples were drawn before inoculating bacteria and following laser treatment. For statistical analysis we used the nonparametric Wilcoxon (paired data) method with a significance level of p <0.05. RESULTS The statistical analysis of median values showed that the groups submitted to laser treatment had low bacterial proliferation. CONCLUSION The laser (AlGaInP), with a dose of 5J/cm2 in both intact skin and in wounds of rats infected with Staphylococcus aureus MRSA, is shown to reduce bacterial proliferation. PMID:23539003

  17. Genotyping of skin and soft tissue infection (SSTI)-associated methicillin-resistant Staphylococcus aureus (MRSA) strains among outpatients in a teaching hospital in Japan: application of a phage-open reading frame typing (POT) kit.

    PubMed

    Maeda, Tadashi; Saga, Tomoo; Miyazaki, Taito; Kouyama, Yuichi; Harada, Sohei; Iwata, Morihiro; Yoshizawa, Sadako; Kimura, Soichiro; Ishii, Yoshikazu; Urita, Yoshihisa; Sugimoto, Motonobu; Yamaguchi, Keizo; Tateda, Kazuhiro

    2012-12-01

    We aimed to elucidate the current epidemiological features of outpatient skin and soft tissue infection (SSTI)-associated methicillin-resistant Staphylococcus aureus (MRSA) in Japan. Altogether, we evaluated the performance of a phage-open reading frame typing (POT) kit for genotyping these MRSA strains. We collected 57 MRSA strains from all outpatients with SSTIs attending a teaching hospital in Japan. Drug susceptibility measurement and genotyping including SCCmec typing, spa typing, multilocus sequence typing, pulsed-field gel electrophoresis, and commercial POT-kit were performed. The majority of strains (39 strains, 68 %) had the SCCmec-II element. Seventeen strains (30 %) with SCCmec-IV accounted for the second largest population. Strains with SCCmec-IV and SCCmec-V appeared multiclonal, and a predominance of Panton-Valentine leukocidin (PVL) gene-negative CC8/spa-CC008 strains, as well as the first isolate of an ST93 strain in Japan, was observed among them. Only one USA300 strain was identified. Strains with SCCmec-IV and SCCmec-V were significantly susceptible to antimicrobials. The PVL gene was found in 5 SCCmec-IV strains and 1 SCCmec-V strain. The POT-kit successfully predicted the SCCmec type in 54 strains (95 %), and typing by POT1 scores was highly concordant with SCCmec typing and spa typing. Moreover, three PVL-positive strains fell into a particular POT type (POT scores, 106-77-113). Simpson's index of the POT-kit was 0.977. In conclusion, the present study clarified the multiclonal nature of outpatient SSTI-associated MRSA in a teaching hospital in Japan. These data also underscore the utility of the POT-kit for non-outbreak surveillance through its simple platform consisting of two multiplex PCRs without sequencing.

  18. Application of the Random Amplified Polymorphic DNA (RAPD) Fingerprinting to Analyze Genetic Variation in Community Associated-Methicillin Resistant Staphylococcus Aureus (CA-MRSA) Isolates in Iran.

    PubMed

    Mobasherizadeh, Sina; Shojaei, Hasan; Havaei, Seyed Asghar; Mostafavizadeh, Kamyar; Davoodabadi, Fazollah; Khorvash, Farzin; Ataei, Behrooz; Daei-Naser, Abbas

    2015-12-18

    The aim of this study was to apply RAPD technique to analyze the genetic variability among the Iranian CA-MRSA isolates.The RAPD amplification was implemented on 25 strains isolated from the anterior nares of 410 healthy children using four randomly selected oligonucleotide primers from the stocks available in our laboratory, including the primers 1254, GE6, OLP6 and OLP13 from our stock. The amplified PCR products were detected on a 1.5% agarose gel and subjected to further analysis to establish the band profiles and genetic relationships using the Gel Compar® program.The Iranian CA-MRSA isolates produced distinct RAPD patterns which varied based on the primer used, however, the primer 1254 revealed highly polymorphic patterns consisting 5 discernable RAPD types (RT), "RT1" (12, 48%), "RT2" (8, 32%), "RT3" (3, 12%), and "RT4 and RT5", (a single RAPD type each, 4%). Phylogenetic analysis based on RAPD profiles divided most of the CA-MRSA isolates into 2 distinct but related RAPD clusters, a small group and two single unrelated RAPD types.This study shows that the simple and cost-effective but rather difficult to optimize RAPD fingerprinting could be used to evaluate genetic and epidemiological relationships of CA-MRSA isolates on condition that the patterns are obtained from carefully optimized laboratory tests.

  19. Application of the Random Amplified Polymorphic DNA (RAPD) Fingerprinting to Analyze Genetic Variation in Community Associated-Methicillin Resistant Staphylococcus Aureus (CA-MRSA) Isolates in Iran

    PubMed Central

    Mobasherizadeh, Sina; Shojaei, Hasan; Havaei, Seyed Asghar; Mostafavizadeh, Kamyar; Davoodabadi, Fazollah; Khorvash, Farzin; Ataei, Behrooz; Daei-Naser, Abbas

    2016-01-01

    The aim of this study was to apply RAPD technique to analyze the genetic variability among the Iranian CA-MRSA isolates. The RAPD amplification was implemented on 25 strains isolated from the anterior nares of 410 healthy children using four randomly selected oligonucleotide primers from the stocks available in our laboratory, including the primers 1254, GE6, OLP6 and OLP13 from our stock. The amplified PCR products were detected on a 1.5% agarose gel and subjected to further analysis to establish the band profiles and genetic relationships using the Gel Compar® program. The Iranian CA-MRSA isolates produced distinct RAPD patterns which varied based on the primer used, however, the primer 1254 revealed highly polymorphic patterns consisting 5 discernable RAPD types (RT), “RT1” (12, 48%), “RT2” (8, 32%), “RT3” (3, 12%), and “RT4 and RT5”, (a single RAPD type each, 4%). Phylogenetic analysis based on RAPD profiles divided most of the CA-MRSA isolates into 2 distinct but related RAPD clusters, a small group and two single unrelated RAPD types. This study shows that the simple and cost-effective but rather difficult to optimize RAPD fingerprinting could be used to evaluate genetic and epidemiological relationships of CA-MRSA isolates on condition that the patterns are obtained from carefully optimized laboratory tests. PMID:27045409

  20. Control of MRSA infection and colonisation in an intensive care unit by GeneOhm MRSA assay and culture methods

    PubMed Central

    2009-01-01

    Background Methicillin-resistant Staphylococcus aureus (MRSA) is one of the major nosocomial pathogens. Due to the diffusion of MRSA strains in both hospital and community settings, prevention and control strategies are receiving increased attention. Approximately 25% to 30% of the population is colonised with S. aureus and 0.2% to 7% with MRSA. The BD GeneOhm MRSA real-time PCR assay offers quicker identification of MRSA-colonised patients than do culture methods. Methods Ninety-five patients admitted to the Intensive Care Unit of IRCCS Policlinico San Matteo of Pavia (Italy) for a period > 24 h were screened for MRSA colonisation with both the culture method and the GeneOhm assay. Results Of the 246 nasal swabs collected from 95 patients, 36 samples were found to be positive by both methods (true-positive). 30% of colonised patients had developed the MRSA infection. Conclusion Our results show that the GeneOhm MRSA assay is a valuable diagnostic tool for detecting MRSA quickly in nasal swabs. This study confirms that colonisation represents a high risk factor for MRSA infection, and that good MRSA surveillance in an Intensive Care Unit is therefore an excellent way to prevent MRSA infection. PMID:19703294

  1. Livestock-Associated MRSA: The Impact on Humans

    PubMed Central

    Cuny, Christiane; Wieler, Lothar H.; Witte, Wolfgang

    2015-01-01

    During the past 25 years an increase in the prevalence of methicillin-resistant Staphylococcus aureus (HA-MRSA) was recorded worldwide. Additionally, MRSA infections may occur outside and independent of hospitals, caused by community associated MRSA (CA-MRSA). In Germany, we found that at least 10% of these sporadic infections are due to livestock-associated MRSA (LA-MRSA), which is initially associated with livestock. The majority of these MRSA cases are attributed to clonal complex CC398. LA-MRSA CC398 colonizes the animals asymptomatically in about half of conventional pig farms. For about 77%–86% of humans with occupational exposure to pigs, nasal carriage has been reported; it can be lost when exposure is interrupted. Among family members living at the same farms, only 4%–5% are colonized. Spread beyond this group of people is less frequent. The prevalence of LA-MRSA in livestock seems to be influenced by farm size, farming systems, usage of disinfectants, and in-feed zinc. LA-MRSA CC398 is able to cause the same kind of infections in humans as S. aureus and MRSA in general. It can be introduced to hospitals and cause nosocomial infections such as postoperative surgical site infections, ventilator associated pneumonia, septicemia, and infections after joint replacement. For this reason, screening for MRSA colonization at hospital admittance is recommended for farmers and veterinarians with livestock contacts. Intrahospital dissemination, typical for HA-MRSA in the absence of sufficient hygiene, has only rarely been observed for LA-MRSA to date. The proportion of LA-MRSA among all MRSA from nosocomial infections is about 3% across Germany. In geographical areas with a comparatively high density of conventional farms, LA-MRSA accounts for up to 10% of MRSA from septicemia and 15% of MRSA from wound infections. As known from comparative genome analysis, LA-MRSA has evolved from human-adapted methicillin-susceptible S. aureus, and the jump to livestock was

  2. The synthesis of phenylalanine-derived C5-substituted rhodanines and their activity against selected methicillin-resistant Staphylococcus aureus (MRSA) strains.

    PubMed

    Hardej, Diane; Ashby, Charles R; Khadtare, Nikhil S; Kulkarni, Shridhar S; Singh, Satyakam; Talele, Tanaji T

    2010-12-01

    A series of rhodanine compounds containing various substituents at the N3- and C5-positions were synthesized and their in vitro activity against a panel of clinically relevant MRSA strains was determined. The anti-MRSA activity of compounds 21 (MIC=3.9 μg/mL, MBC=7.8 μg/mL) and 22 (MIC=1.95 μg/mL, MBC=7.8 μg/mL) was significantly greater than that of the lead compounds, 1-3 and reference antibiotics penicillin G (MIC=31.25 μg/mL) and ciprofloxacin (MIC=7.8 μg/mL) and comparable to that of vancomycin (MIC=0.97 μg/mL). Compounds 21 and 22 were found to be bactericidal at only 2-4-fold higher than their MIC concentrations. In addition, their MIC values remained unchanged in the presence or absence of 10% serum. Overall, the results suggest that compounds 21 and 22 may be of potential use in the treatment of MRSA infections.

  3. Patients and Loved Ones: Information about MRSA in Healthcare Settings

    MedlinePlus

    ... infections. Some staph germs are resistant to several antibiotics, meaning the drugs are no longer able to cure the infections. Methicillin-resistant Staphylococcus aureus or MRSA is a type of ...

  4. Engineering MRSA antimicrobials that are refractory to resistance development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methicillin resistant Staphylococcus aureus (MRSA) is one of the most costly multi-drug resistant pathogens to both human animal health, with billions of dollars are spent annually to treat human infections. MRSA is also appearing in livestock (bovine, porcine, poultry) as well as companion animal...

  5. MRSA infection in the neonatal intensive care unit.

    PubMed

    Giuffrè, Mario; Bonura, Celestino; Cipolla, Domenico; Mammina, Caterina

    2013-05-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is well known as one of the most frequent etiological agents of healthcare-associated infections. The epidemiology of MRSA is evolving with emergence of community-associated MRSA, the clonal spread of some successful clones, their spillover into healthcare settings and acquisition of antibacterial drug resistances. Neonatal intensive care unit (NICU) patients are at an especially high risk of acquiring colonization and infection by MRSA. Epidemiology of MRSA in NICU can be very complex because outbreaks can overlap endemic circulation and make it difficult to trace transmission routes. Moreover, increasing prevalence of community-associated MRSA can jeopardize epidemiological investigation, screening and effectiveness of control policies. Surveillance, prevention and control strategies and clinical management have been widely studied and are still the subject of scientific debate. More data are needed to determine the most cost-effective approach to MRSA control in NICU in light of the local epidemiology.

  6. A New Synthetic Peptide with In vitro Antibacterial Potential Against Escherichia coli O157:H7 and Methicillin-Resistant Staphylococcus aureus (MRSA).

    PubMed

    Prada, Y A; Guzmán, F; Rondón, P; Escobar, P; Ortíz, C; Sierra, D A; Torres, R; Mejía-Ospino, E

    2016-09-01

    In this work, we performed the rational design of a cationic antimicrobial peptide, GIBIMPY4, using the software DEPRAMPs developed at the GIBIM research group. GIBIMPY4 has a length of 17 amino acids, it is amphipathic, its structure is α-helix and it has a net charge of (+5). Solid-phase peptide synthesis was performed using the Fmoc strategy in acid medium. The primary structure was confirmed by MALDI-TOF mass spectrometry. The antimicrobial activity of the peptide was evaluated by broth microdilution method by measuring optical density in 96-well microplates. The minimal inhibitory concentration of GIBIMPY4 to kill 50 % of the bacterial cells (MIC50) was 6.20 ± 0.02 µM for MRSA and 4.55 ± 0.02 µM for E. coli O157:H7, while also reporting a bacteriostatic effect for the later. GIBIMPY4 activity was sensitive to salt concentration in E. coli but insignificant effect in its activity against MRSA. The peptide seems to be a broad-spectrum antimicrobial agent based on the results against Gram-positive and Gram-negative bacteria and was specific for bacterial cells E. coli O157:H7 with index of specificity equal to 9.01 in vitro assays.

  7. A New Synthetic Peptide with In vitro Antibacterial Potential Against Escherichia coli O157:H7 and Methicillin-Resistant Staphylococcus aureus (MRSA).

    PubMed

    Prada, Y A; Guzmán, F; Rondón, P; Escobar, P; Ortíz, C; Sierra, D A; Torres, R; Mejía-Ospino, E

    2016-09-01

    In this work, we performed the rational design of a cationic antimicrobial peptide, GIBIMPY4, using the software DEPRAMPs developed at the GIBIM research group. GIBIMPY4 has a length of 17 amino acids, it is amphipathic, its structure is α-helix and it has a net charge of (+5). Solid-phase peptide synthesis was performed using the Fmoc strategy in acid medium. The primary structure was confirmed by MALDI-TOF mass spectrometry. The antimicrobial activity of the peptide was evaluated by broth microdilution method by measuring optical density in 96-well microplates. The minimal inhibitory concentration of GIBIMPY4 to kill 50 % of the bacterial cells (MIC50) was 6.20 ± 0.02 µM for MRSA and 4.55 ± 0.02 µM for E. coli O157:H7, while also reporting a bacteriostatic effect for the later. GIBIMPY4 activity was sensitive to salt concentration in E. coli but insignificant effect in its activity against MRSA. The peptide seems to be a broad-spectrum antimicrobial agent based on the results against Gram-positive and Gram-negative bacteria and was specific for bacterial cells E. coli O157:H7 with index of specificity equal to 9.01 in vitro assays. PMID:27301970

  8. Comparison of ESBL – And AmpC Producing Enterobacteriaceae and Methicillin-Resistant Staphylococcus aureus (MRSA) Isolated from Migratory and Resident Population of Rooks (Corvus frugilegus) in Austria

    PubMed Central

    Mehinagic, Kemal; Rosengarten, Renate; Hoelzl, Franz; Knauer, Felix; Walzer, Chris

    2013-01-01

    In order to test whether rooks (Corvus frugilegus) represent good indicators for the potential circulation of antibiotics in their native habitat, two populations with different migratory behavior were tested for the presence of beta-lactamase producing Enterobacteriaceae and methicillin-resistant Staphylococcus aureus (MRSA). In all, 54 and 102 samples of fresh feces of a migratory and a resident population were investigated. A total of 24 and 3 cefotaxime-resistant enterobacterial isolates were obtained from the migratory and resident population, respectively. In these isolates CTX-M-1 (n = 15), CTX-M-3 (n = 3), and CTX-M-15 (n = 3) genes were detected. TEM-1 and OXA-1 were associated with CTX-M in 3 and 2 isolates, respectively. In two E. coli isolates CMY-2 could be detected, where from one isolate displayed an overexpression of chromosomal AmpC as well. Among E. coli isolates the most common phylogenetic group was A (n = 11) and ST1683 (n = 5). In one E. coli of B2-ST131 the rfbO25b locus was detected. Three Enterobacter isolates were stably derepressed AmpC-producers. In five samples of the migratory population, PVL positive MRSA could be isolated. Two isolates were typed SCCmec IVa, spa type t127, and ST1. Three isolates carried a SCCmec type IVc, with spa type t852 and ST22. The highly significant difference of the occurrence of antibiotic resistance between the migratory population from eastern Europe compared to resident population in our study indicates that rooks may be good indicator species for the evaluation of environmental contamination with antibiotic resistant bacteria, especially due to their ecology, foraging behavior and differing migratory behavior. PMID:24391878

  9. Assessment of athletic health care facility surfaces for MRSA in the secondary school setting.

    PubMed

    Montgomery, Kyle; Ryan, Timothy J; Krause, Andrew; Starkey, Chad

    2010-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) was once largely a hospital-acquired infection, but increasingly, community-associated MRSA (CA-MRSA) is causing outbreaks among otherwise healthy people in athletic settings. Secondary school athletic trainers, student athletes, and the general student population may be at elevated risk of MRSA infection. To identify the prevalence of MRSA on surfaces in high school athletic training settings, 10 rural high school athletic training facilities and locker rooms were sampled for MRSA. Results showed 90% of facilities had two or more positive MRSA surfaces, while one school had no recoverable MRSA colonies. Of all surfaces tested (N=90), 46.7% produced a positive result. From this limited sample, it is evident that significant exposure opportunities to MRSA exist in athletic training clinics and adjacent facilities for both the patient and the clinician. Furthermore, the findings point to the need for community hygiene education about skin and soft tissue infections like MRSA.

  10. Genotyping of community-associated methicillin resistant Staphylococcus aureus (CA-MRSA) in a tertiary care centre in Mysore, South India: ST2371-SCCmec IV emerges as the major clone.

    PubMed

    Rajan, Vineeth; Schoenfelder, Sonja M K; Ziebuhr, Wilma; Gopal, Shubha

    2015-08-01

    The burden of community-associated methicillin resistant Staphylococcus aureus (CA-MRSA) is on the rise in population and clinical settings on account of the adaptability and virulence traits of this pathogen. We characterized 45 non-duplicate CA-MRSA strains implicated mainly in skin and soft tissue infections (SSTIs) in a tertiary care hospital in Mysore, South India. All the isolates were genotyped by staphylococcal cassette chromosome mec (SCCmec) typing, staphylococcal protein A (spa) typing, accessory gene regulator (agr) typing, and multi-locus sequence typing (MLST). Four sequence types (STs) belonging to three major clonal complexes (CCs) were identified among the isolates: CC22 (ST2371 and ST22), CC1 (ST772) and CC8 (ST8). The majority (53.3%) of the isolates was of the genotype ST2371-t852-SCCmec IV [sequence type-spa type-SCCmec type], followed by ST22-t852-SCCmec IV (22.2%), ST772-t657-SCCmec V (13.3%) and ST8-t008-SCCmec IV (11.1%). ST237I, a single locus variant of ST22 (EMRSA-15 clone), has not been reported previously from any of the Asian countries. Our study also documents for the first time, the appearance of ST8-SCCmec IV (USA300) strains in India. Representative strains of the STs were further analyzed by pulsed field gel electrophoresis (PFGE). agr typing detected type I or II alleles in the majority of the isolates. All the isolates were positive for the leukotoxin gene, pvl (Panton-Valentine leukocidin) and the staphylococcal enterotoxin gene cluster, egc. Interestingly, multidrug resistance (resistance to ⩾3 classes of non-beta-lactam antibiotics) was observed in 77.8% (n=35) of the isolates. The highest (75.5%) resistance was recorded for ciprofloxacin, followed by erythromycin (53.3%), and quinupristin-dalfopristin (51.1%). Inducible clindamycin-resistance was identified in 37.7% of the isolates and it was attributed to the presence of erm(A), erm(C) and a combination of erm(A) and erm(C) genes. Isolates which showed a phenotypic

  11. MRSA Infections in HIV-Infected People Are Associated with Decreased MRSA-Specific Th1 Immunity

    PubMed Central

    Utay, Netanya S.; Roque, Annelys; Timmer, J. Katherina; Morcock, David R.; DeLeage, Claire; Somasunderam, Anoma; Weintrob, Amy C.; Agan, Brian K.; Estes, Jacob D.; Crum-Cianflone, Nancy F.; Douek, Daniel C.

    2016-01-01

    People with HIV infection are at increased risk for community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) skin and soft tissue infections (SSTIs). Lower CD4 T-cell counts, higher peak HIV RNA levels and epidemiological factors may be associated with increased risk but no specific immune defect has been identified. We aimed to determine the immunologic perturbations that predispose HIV-infected people to MRSA SSTIs. Participants with or without HIV infection and with MRSA SSTI, MRSA colonization or negative for MRSA were enrolled. Peripheral blood and skin biopsies from study participants were collected. Flow cytometry, flow cytometry with microscopy, multiplex assays of cell culture supernatants and immunohistochemistry were used to evaluate the nature of the immune defect predisposing HIV-infected people to MRSA infections. We found deficient MRSA-specific IFNγ+ CD4 T-cell responses in HIV-infected people with MRSA SSTIs compared to MRSA-colonized participants and HIV-uninfected participants with MRSA SSTIs. These IFNγ+ CD4 T cells were less polyfunctional in HIV-infected participants with SSTIs compared to those without SSTIs. However, IFNγ responses to cytomegalovirus and Mycobacterium avium antigens and MRSA-specific IL-17 responses by CD4 T cells were intact. Upon stimulation with MRSA, peripheral blood mononuclear cells from HIV-infected participants produced less IL-12 and IL-15, key drivers of IFNγ production. There were no defects in CD8 T-cell responses, monocyte responses, opsonization, or phagocytosis of Staphylococcus aureus. Accumulation of CD3 T cells, CD4 T cells, IL-17+ cells, myeloperoxidase+ neutrophils and macrophage/myeloid cells to the skin lesions were similar between HIV-infected and HIV-uninfected participants based on immunohistochemistry. Together, these results indicate that MRSA-specific IFNγ+ CD4 T-cell responses are essential for the control of initial and recurrent MRSA infections in HIV-infected people. PMID

  12. MRSA and the Workplace

    MedlinePlus

    ... Topics Publications and Products Programs Contact NIOSH NIOSH MRSA and the Workplace Recommend on Facebook Tweet Share ... infections from their healthcare provider Other FAQs About MRSA Signs and Symptoms What does a staph or ...

  13. Methicillin-resistant Staphylococcus aureus laryngitis.

    PubMed

    Liakos, Tracey; Kaye, Keith; Rubin, Adam D

    2010-09-01

    Infections due to methicillin-resistant Staphylococcus aureus (MRSA) have become more prevalent, in part because of the emergence and spread of community-acquired MRSA. This trend is particularly concerning because of the significant rates of morbidity and mortality associated with MRSA infections, and because MRSA strains are often resistant to many classes of antibiotics. Reports of infections of the head and neck, including wound infections, cellulitis, sinusitis, otitis media, and otitis externa, are well documented. However, to our knowledge, there have been no reports of bacterial laryngitis due to MRSA. We report the first published case of bacterial laryngitis caused by MRSA.

  14. Anti-MRSA drug use and antibiotic susceptibilities of MRSA at a university hospital in Japan from 2007 to 2011.

    PubMed

    Shigemura, Katsumi; Osawa, Kayo; Mukai, Akira; Yoshida, Hiroyuki; Fujisawa, Masato; Arakawa, Soichi

    2013-05-01

    The purpose of this study is to examine the use of anti-methicillin-resistant Staphylococcus aureus (MRSA) drugs, such as vancomycin (VCM), teicoplanin (TEIC), arbekasin (ABK) and linezolid (LZD), and the antibiotic susceptibilities of MRSAs in Kobe University Hospital. We investigated MRSA isolation and use of anti-MRSA drugs and susceptibilities of MRSA, using linear regression analysis, from 2007 to 2011, and checked for correlation between the use of these drug and the antibiotic susceptibilities of MRSA. The overall monthly isolation rates of MRSA decreased from a mean of 84.8% in 2007 to 70.0% in 2011 (r=0.946, P=0.015, b=-0.220), and the monthly isolation rate of MRSA in inpatients decreased from a mean of 78.6% in 2007 to 57.7% in 2011 (r=0.952, P=0.012, b=-0.160). From 2007 to 2011, VCM consumption significantly increased (r=0.916, P=0.029, b=0.055), whereas TEIC and LZD use remained stable during the study period. In addition, ABK use significantly decreased from 23.8 defined daily dose (DDD) per 1000 patient-days in 2007 to 5.2 DDD per 1000 in 2011 (r=0.902, P=0.036, b=-0.216). Susceptibility rates of MRSA were almost 100% to TEIC and VCM. The rates of MRSA to ABK and LZD significantly increased (r=0.959, P=0.010, b=2.137 for ABK and r=0.933, P=0.020, b=3.111 for LZD). In conclusion, our findings indicated a decreased MRSA isolation rate and the effective use of anti-MRSA drugs (VCM, TEIC, ABK and LZD), and improved susceptibility rates to anti-MRSA drugs, suggesting the possibilities that appropriate and early use of anti-MRSA drugs may cause the decrease of MRSA isolation.

  15. Can EDTA Change MRSA into MSSA? A Future Prospective!

    PubMed Central

    Jain, Sonia; Sarkar, Soma; Ghosh, Sougata; (Mitra), Anita Nandi; Sinha, Anuradha; Chakravorty, Sriparna

    2016-01-01

    Introduction In the present era we are left behind with limited options for the treatment of serious infections caused by multidrug resistant S.aureus, most remarkably nosocomially acquired Methicillin resistant S.aureus (MRSA). The problem increases more when these strains easily become multidrug resistant (MDR) due to biofilm formation. Those staphylococcal species that are vancomycin and linezolid resistant are also resistant to other antistaphylococcal agents which call for an urgent intervention to develop newer antimicrobial agents. Aim The present study was undertaken with the aim to evaluate the antibiofilm effect of EDTA against the biofilm forming MRSA isolates, isolated from different clinical infections. Materials and Methods The biofilms formed on polystyrene microtitre plates by the MRSA strains were treated by different concentrations of EDTA to find out its anti-biofilm activity. Further simultaneously the antibiotic susceptibility pattern was noted down to check whether the MRSA strains become MSSA (Methicillin sensitive S.aureus). Results Our data demonstrates that EDTA at 4mM concentration inhibits biofilm of MRSA and at 20 mM have an ability to reduce and dissociate the biofilm membrane, allowing the antibiotics to enter and convert MRSA strains into MSSA. Conclusion These findings suggest that commercially available EDTA could be used in future to control MRSA and its biofilm- related infections. PMID:27042464

  16. Characterisation of MRSA from Malta and the description of a Maltese epidemic MRSA strain.

    PubMed

    Scicluna, E A; Shore, A C; Thürmer, A; Ehricht, R; Slickers, P; Borg, M A; Coleman, D C; Monecke, S

    2010-02-01

    Malta has one of the highest prevalence rates of methicillin-resistant Staphylococcus aureus (MRSA) in Europe. However, only limited typing data are currently available. In order to address this situation, 45 MRSA isolates from the Mater Dei Hospital in Msida, Malta, were characterised using DNA microarrays. The most common strain was ST22-MRSA-IV (UK-EMRSA-15, 30 isolates). Sporadic strains included ST36-MRSA-II (UK-EMRSA-16, two isolates), PVL-positive ST80-MRSA-IV (European Clone, one isolate), ST228-MRSA-I (Italian Clone/South German Epidemic Strain, one isolate) and ST239-MRSA-III (Vienna/Hungarian/Brazilian Epidemic Strain, one isolate). Ten MRSA isolates belonged to a clonal complex (CC) 5/ST149, spa type t002 strain. This strain harboured an SCCmec IV element (mecA, delta mecR, ugpQ, dcs, ccrA2 and ccrB2), as well as novel alleles of ccrA/B and the fusidic acid resistance element Q6GD50 (previously described in the sequenced strain MSSA476, BX571857.1:SAS0043). It also carried the gene for enterotoxin A (sea) and the egc enterotoxin locus, as well as (in nine out of ten isolates) genes encoding the toxic shock syndrome toxin (tst1) and enterotoxins C and L (sec, sel). While the presence of the other MRSA strains suggests foreign importation due to travel between Malta and other European countries, the CC5/t002 strain appears, so far, to be restricted to Malta.

  17. Bullous impetigo in children infected with methicillin-resistant Staphylococcus aureus alone or in combination with methicillin-susceptible S. aureus: analysis of genetic characteristics, including assessment of exfoliative toxin gene carriage.

    PubMed

    Shi, Da; Higuchi, Wataru; Takano, Tomomi; Saito, Kohei; Ozaki, Kyoko; Takano, Misao; Nitahara, Yoshiyuki; Yamamoto, Tatsuo

    2011-05-01

    Among bullous impetigo isolates, exfoliative toxin (ET) gene carriage was found in 61.5% of methicillin-resistant Staphylococcus aureus (MRSA) isolates versus 90.6% of methicillin-susceptible S. aureus (MSSA) isolates. MRSA-only cases were ETB or ETA positive, while MRSA/MSSA coinfection cases were ET negative for MRSA but ETA positive for MSSA. Collagen adhesin may facilitate some MRSA infections.

  18. Community-Acquired Methicillin-Resistant "Staphylococcus aureus": Considerations for School Nurses

    ERIC Educational Resources Information Center

    Alex, Aniltta; Letizia, MariJo

    2007-01-01

    Methicillin-resistant "Staphylococcus aureus" (MRSA) is a disease-causing organism that has been present in hospital settings since the 1960s. However, a genetically distinct strain of MRSA, called community-acquired methicillin-resistant "Staphylococcus aureus" (CA-MRSA), has emerged in recent years in community settings among healthy…

  19. Characterization of Staphylococcus aureus mutants expressing reduced susceptibility to common house-cleaners

    PubMed Central

    Davis, A.O.; O’Leary, J.O.; Muthaiyan, A.; Langevin, M.J.; Delgado, A.; Abalos, A.T.; Fajardo, A.R.; Marek, J.; Wilkinson, B.J.; Gustafson, J.E.

    2013-01-01

    Aims To characterize mutants of Staphylococcus aureus expressing reduced susceptibility to house cleaners (HC), assess the impact of the alternative sigma factor SigB on HC susceptibility, and determine the MIC of clinical methicillin-resistant S. aureus (MRSA) to a HC. Methods and Results Susceptibility to HC, HC components, H2O2, vancomycin and oxacillin and physiological parameters were determined for HC-reduced susceptibility (HCRS) mutants, parent strain COL and COLsigB::kan. HCRS mutants selected with three HC expressed reduced susceptibility to multiple HC, HC components, H2O2 and vancomycin. Two unique HCRS mutants also lost the methicillin resistance determinant. In addition, all HCRS mutants exhibited better growth at two temperatures, and one HCRS mutant expressed reduced carotenoid production. COLsigB::kan demonstrated increased susceptibility to all HC and many HC components. sigB operon mutations were not detected in one HCRS mutant background. Of 76 clinical MRSA, 20 exhibited reduced susceptibility to a HC. Conclusions HCRS mutants demonstrate altered susceptibility to multiple antimicrobials. While sigB is required for full HC resistance, one HCRS mechanism does not involve sigB operon mutations. Clinical MRSA expressing reduced susceptibility to a common HC were detected. Significance and Impact of the Study This study suggests that HCRS mutants are not protected against, nor selected by, practical HC concentrations. PMID:15659191

  20. Transmission of MRSA between companion animals and infected human patients presenting to outpatient medical care facilities.

    PubMed

    Ferreira, Jorge Pinto; Anderson, Kevin L; Correa, Maria T; Lyman, Roberta; Ruffin, Felicia; Reller, L Barth; Fowler, Vance G

    2011-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a significant pathogen in both human and veterinary medicine. The importance of companion animals as reservoirs of human infections is currently unknown. The companion animals of 49 MRSA-infected outpatients (cases) were screened for MRSA carriage, and their bacterial isolates were compared with those of the infected patients using Pulsed-Field Gel Electrophoresis (PFGE). Rates of MRSA among the companion animals of MRSA-infected patients were compared to rates of MRSA among companion animals of pet guardians attending a "veterinary wellness clinic" (controls). MRSA was isolated from at least one companion animal in 4/49 (8.2%) households of MRSA-infected outpatients vs. none of the pets of the 50 uninfected human controls. Using PFGE, patient-pets MRSA isolates were identical for three pairs and discordant for one pair (suggested MRSA inter-specie transmission p-value = 0.1175). These results suggest that companion animals of MRSA-infected patients can be culture-positive for MRSA, representing a potential source of infection or re-infection for humans. Further studies are required to better understand the epidemiology of MRSA human-animal inter-specie transmission.

  1. Dual Site Sampling Improved Detection Rates for MRSA Colonization in Patients with Cutaneous Abscesses

    PubMed Central

    May, L.; McCann, C.; Brooks, G.; Rothman, R.; Miller, L.; Jordan, J.

    2014-01-01

    Extranasal sites are common reservoirs of Staphylococcus aureus colonization, and may be relevant for methicillin-resistant S. aureus (MRSA) screening and infection control strategies. The objective here was to determine whether inguinal specimens could also be screened using Xpert SA Nasal Complete assay for MRSA. Results were compared to broth enrichment culture. Among 162 consented adults seeking care in the Emergency Department for cutaneous abscesses, inguinal specimens were found positive for MRSA more often than nares specimens; 24% and 26% by PCR or culture, respectively compared to 19% each by PCR or culture. Overall, 6% of adults colonized with MRSA would have been missed by nares screening alone. Compared to culture, Xpert SA Nasal Complete assay demonstrated sensitivity and specificity of 89% and 97%, respectively for detecting nares and/or inguinal MRSA colonization. In conclusion, inguinal specimens were a more common reservoir for MRSA than nares specimens in this population of patients. PMID:24958641

  2. Methicillin-Resistant Staphylococcus aureus Recovered from Healthcare- and Community-Associated Infections in Egypt.

    PubMed

    Abdel-Maksoud, Mohamed; El-Shokry, Mona; Ismail, Ghada; Hafez, Soad; El-Kholy, Amani; Attia, Ehab; Talaat, Maha

    2016-01-01

    Background. Methicillin-resistant Staphylococcus aureus (MRSA) has created significant epidemiological, infection-control, and therapeutic management challenges during the past three decades. Aim. To analyze the pattern of resistance of healthcare- and community-associated MRSA in Egypt and the trend of resistance of HA-MRSA over time (2005-2013). Methods. MRSA isolates were recovered from healthcare-associated (HA) and community-associated (CA) Staphylococcus aureus (S. aureus) infections. They were tested against 11 antimicrobial discs and the minimal inhibitory concentration (MIC) of vancomycin was determined. Inducible clindamycin resistance (iMLSB) was also screened using D-test. Findings. Of 631 S. aureus, MRSA was identified in 343 (76.6%) and 21 (11.5%) of HA and CA S. aureus isolates, respectively. The proportion of HA-MRSA increased significantly from 48.6% in 2005 to 86.8% in 2013 (p value < 0.001). Multidrug resistance (MDR) was observed in 85.8% of HA-MRSA and 48.6% of CA-MRSA. Vancomycin intermediate resistant S. aureus (VISA) was detected in 1.2% of HA-MRSA and none was detected in CA-MRSA. Among HA-MRSA strains, 5.3% showed iMLSB compared to 9.5% among CA-MRSA. Conclusion. The upsurge of the prevalence rates of HA-MRSA over time is alarming and urges for an effective infection control strategy and continuous monitoring of antimicrobial use.

  3. Methicillin-Resistant Staphylococcus aureus Recovered from Healthcare- and Community-Associated Infections in Egypt

    PubMed Central

    Abdel-Maksoud, Mohamed; Ismail, Ghada; Hafez, Soad; El-Kholy, Amani; Attia, Ehab; Talaat, Maha

    2016-01-01

    Background. Methicillin-resistant Staphylococcus aureus (MRSA) has created significant epidemiological, infection-control, and therapeutic management challenges during the past three decades. Aim. To analyze the pattern of resistance of healthcare- and community-associated MRSA in Egypt and the trend of resistance of HA-MRSA over time (2005–2013). Methods. MRSA isolates were recovered from healthcare-associated (HA) and community-associated (CA) Staphylococcus aureus (S. aureus) infections. They were tested against 11 antimicrobial discs and the minimal inhibitory concentration (MIC) of vancomycin was determined. Inducible clindamycin resistance (iMLSB) was also screened using D-test. Findings. Of 631 S. aureus, MRSA was identified in 343 (76.6%) and 21 (11.5%) of HA and CA S. aureus isolates, respectively. The proportion of HA-MRSA increased significantly from 48.6% in 2005 to 86.8% in 2013 (p value < 0.001). Multidrug resistance (MDR) was observed in 85.8% of HA-MRSA and 48.6% of CA-MRSA. Vancomycin intermediate resistant S. aureus (VISA) was detected in 1.2% of HA-MRSA and none was detected in CA-MRSA. Among HA-MRSA strains, 5.3% showed iMLSB compared to 9.5% among CA-MRSA. Conclusion. The upsurge of the prevalence rates of HA-MRSA over time is alarming and urges for an effective infection control strategy and continuous monitoring of antimicrobial use. PMID:27433480

  4. Methicillin-Resistant Staphylococcus aureus (MRSA) Diagnosis

    MedlinePlus

    ... Resistance Funding Information National Library of Medicine, MedlinePlus ​​​​​​​​​​​​ Javascript Error Your browser JavaScript is turned off causing certain features of the ...

  5. Prevalence and characterization of Methicillin-resistant Staphylococcus aureus isolates from retail meat and humans in Georgia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is increasing interest in the presence of Staphylococcus aureus, specifically methicillin-resistant S. aureus (MRSA), on retail meat products. In this study, staphylococci were isolated from retail pork and retail beef in Georgia and MRSA from the products were compared to human MRSA from the...

  6. Prevalence of Staphylococcus aureus and Methicillin-Resistant Staphylococcus aureus in Retail Ready-to-Eat Foods in China.

    PubMed

    Yang, Xiaojuan; Zhang, Jumei; Yu, Shubo; Wu, Qingping; Guo, Weipeng; Huang, Jiahui; Cai, Shuzhen

    2016-01-01

    Staphylococcus aureus, particularly methicillin-resistant S.aureus (MRSA), is a life-threatening pathogen in humans, and its presence in food is a public health concern. MRSA has been identified in foods in China, but little information is available regarding MRSA in ready-to-eat (RTE) foods. We aimed to investigate the prevalence of S. aureus and MRSA in Chinese retail RTE foods. All isolated S. aureus were tested for antimicrobial susceptibility, and MRSA isolates were further characterized by multilocus sequence typing (MLST) and staphylococcal cassette chromosome mec (SCCmec) typing. Of the 550 RTE foods collected from 2011 to 2014, 69 (12.5%) were positive for S. aureus. Contamination levels were mostly in the range of 0.3-10 most probable number (MPN)/g, with five samples exceeding 10 MPN/g. Of the 69 S. aureus isolates, seven were identified as MRSA by cefoxitin disc diffusion test. Six isolates were mecA-positive, while no mecC-positive isolates were identified. In total, 75.8% (47/62) of the methicillin-susceptible S. aureus isolates and all of the MRSA isolates were resistant to three or more antibiotics. Amongst the MRSA isolates, four were identified as community-acquired strains (ST59-MRSA-IVa (n = 2), ST338-MRSA-V, ST1-MRSA-V), while one was a livestock-associated strain (ST9, harboring an unreported SCCmec type 2C2). One novel sequence type was identified (ST3239), the SCCmec gene of which could not be typed. Overall, our findings showed that Chinese retail RTE foods are likely vehicles for transmission of multidrug-resistant S. aureus and MRSA lineages. This is a serious public health risk and highlights the need to implement good hygiene practices. PMID:27375562

  7. Prevalence of Staphylococcus aureus and Methicillin-Resistant Staphylococcus aureus in Retail Ready-to-Eat Foods in China

    PubMed Central

    Yang, Xiaojuan; Zhang, Jumei; Yu, Shubo; Wu, Qingping; Guo, Weipeng; Huang, Jiahui; Cai, Shuzhen

    2016-01-01

    Staphylococcus aureus, particularly methicillin-resistant S.aureus (MRSA), is a life-threatening pathogen in humans, and its presence in food is a public health concern. MRSA has been identified in foods in China, but little information is available regarding MRSA in ready-to-eat (RTE) foods. We aimed to investigate the prevalence of S. aureus and MRSA in Chinese retail RTE foods. All isolated S. aureus were tested for antimicrobial susceptibility, and MRSA isolates were further characterized by multilocus sequence typing (MLST) and staphylococcal cassette chromosome mec (SCCmec) typing. Of the 550 RTE foods collected from 2011 to 2014, 69 (12.5%) were positive for S. aureus. Contamination levels were mostly in the range of 0.3–10 most probable number (MPN)/g, with five samples exceeding 10 MPN/g. Of the 69 S. aureus isolates, seven were identified as MRSA by cefoxitin disc diffusion test. Six isolates were mecA-positive, while no mecC-positive isolates were identified. In total, 75.8% (47/62) of the methicillin-susceptible S. aureus isolates and all of the MRSA isolates were resistant to three or more antibiotics. Amongst the MRSA isolates, four were identified as community-acquired strains (ST59-MRSA-IVa (n = 2), ST338-MRSA-V, ST1-MRSA-V), while one was a livestock-associated strain (ST9, harboring an unreported SCCmec type 2C2). One novel sequence type was identified (ST3239), the SCCmec gene of which could not be typed. Overall, our findings showed that Chinese retail RTE foods are likely vehicles for transmission of multidrug-resistant S. aureus and MRSA lineages. This is a serious public health risk and highlights the need to implement good hygiene practices. PMID:27375562

  8. Prevalence of Staphylococcus aureus and Methicillin-Resistant Staphylococcus aureus in Retail Ready-to-Eat Foods in China.

    PubMed

    Yang, Xiaojuan; Zhang, Jumei; Yu, Shubo; Wu, Qingping; Guo, Weipeng; Huang, Jiahui; Cai, Shuzhen

    2016-01-01

    Staphylococcus aureus, particularly methicillin-resistant S.aureus (MRSA), is a life-threatening pathogen in humans, and its presence in food is a public health concern. MRSA has been identified in foods in China, but little information is available regarding MRSA in ready-to-eat (RTE) foods. We aimed to investigate the prevalence of S. aureus and MRSA in Chinese retail RTE foods. All isolated S. aureus were tested for antimicrobial susceptibility, and MRSA isolates were further characterized by multilocus sequence typing (MLST) and staphylococcal cassette chromosome mec (SCCmec) typing. Of the 550 RTE foods collected from 2011 to 2014, 69 (12.5%) were positive for S. aureus. Contamination levels were mostly in the range of 0.3-10 most probable number (MPN)/g, with five samples exceeding 10 MPN/g. Of the 69 S. aureus isolates, seven were identified as MRSA by cefoxitin disc diffusion test. Six isolates were mecA-positive, while no mecC-positive isolates were identified. In total, 75.8% (47/62) of the methicillin-susceptible S. aureus isolates and all of the MRSA isolates were resistant to three or more antibiotics. Amongst the MRSA isolates, four were identified as community-acquired strains (ST59-MRSA-IVa (n = 2), ST338-MRSA-V, ST1-MRSA-V), while one was a livestock-associated strain (ST9, harboring an unreported SCCmec type 2C2). One novel sequence type was identified (ST3239), the SCCmec gene of which could not be typed. Overall, our findings showed that Chinese retail RTE foods are likely vehicles for transmission of multidrug-resistant S. aureus and MRSA lineages. This is a serious public health risk and highlights the need to implement good hygiene practices.

  9. Efficacy of alcohol gel for removal of methicillin-resistant Staphylococcus aureus from hands of colonized patients.

    PubMed

    Sunkesula, Venkata; Kundrapu, Sirisha; Macinga, David R; Donskey, Curtis J

    2015-02-01

    Of 82 patients with methicillin-resistant Staphylococcus aureus (MRSA) colonization, 67 (82%) had positive hand cultures for MRSA. A single application of alcohol gel (2 mL) consistently reduced the burden of MRSA on hands. However, incomplete removal of MRSA was common, particularly in those with a high baseline level of recovery. PMID:25633009

  10. Potential role of pet animals in household transmission of methicillin-resistant Staphylococcus aureus: a narrative review.

    PubMed

    Bramble, Manuel; Morris, Daniel; Tolomeo, Pam; Lautenbach, Ebbing

    2011-06-01

    In this narrative review, we found numerous reports suggesting that dogs and cats may play a role in household methicillin-resistant Staphylococcus aureus (MRSA) transmission and recurrent MRSA infection in human contacts. Future work should emphasize elucidating more clearly the prevalence of MRSA in household pets and characterize transmission dynamics of MRSA humans and pet animals.

  11. Potential role of pet animals in household transmission of methicillin-resistant Staphylococcus aureus: a narrative review.

    PubMed

    Bramble, Manuel; Morris, Daniel; Tolomeo, Pam; Lautenbach, Ebbing

    2011-06-01

    In this narrative review, we found numerous reports suggesting that dogs and cats may play a role in household methicillin-resistant Staphylococcus aureus (MRSA) transmission and recurrent MRSA infection in human contacts. Future work should emphasize elucidating more clearly the prevalence of MRSA in household pets and characterize transmission dynamics of MRSA humans and pet animals. PMID:21142959

  12. [Evaluation of the impact of different lengths of pre-enrichment in a nutritive broth and prolonged incubation of MRSA-ID, a chromogenic agar medium, on its performances for identifying methicillin-resistant Staphylococcus aureus in screening samples].

    PubMed

    Grandin, S; Deschamps, C; Magdoud, F; Zihoune, N; Branger, C; Eveillard, M

    2009-05-01

    MRSA-carrier screening is recommended to prevent MRSA dissemination in hospitals. Rapid and specific detection of MRSA in the laboratory is a key element in enabling control measures. Our objective was to evaluate the impact of different lengths of pre-incubation in a nutritive broth and prolonged incubation of MRSA-ID, a chromogenic agar medium, on its performances for identifying MRSA in screening samples. According to our results, short-length pre-enrichments only provided a weak increase of sensitivity as compared to the absence of pre-enrichment. On the contrary, the sensitivity increase provided by an overnight pre-enrichment was significant. The prolongation of incubation in the chromogenic agar medium (48 hours instead of 24 hours) did not provide any significant increase of sensitivity but was associated with a strong and significant loss of specificity. Therefore, it seems relevant to reject prolonged incubation of selective agar media and to make a choice between the absence of pre-enrichment (faster results) and an overnight pre-enrichment (higher sensitivity), according to local epidemiology and local practices implemented for prevention.

  13. Genomic insights into the emergence and spread of international clones of healthcare-, community- and livestock-associated meticillin-resistant Staphylococcus aureus: Blurring of the traditional definitions.

    PubMed

    Bal, A M; Coombs, G W; Holden, M T G; Lindsay, J A; Nimmo, G R; Tattevin, P; Skov, R L

    2016-09-01

    The evolution of meticillin-resistant Staphylococcus aureus (MRSA) from meticillin-susceptible S. aureus has been a result of the accumulation of genetic elements under selection pressure from antibiotics. The traditional classification of MRSA into healthcare-associated MRSA (HA-MRSA) and community-associated MRSA (CA-MRSA) is no longer relevant as there is significant overlap of identical clones between these groups, with an increasing recognition of human infection caused by livestock-associated MRSA (LA-MRSA). Genomic studies have enabled us to model the epidemiology of MRSA along these lines. In this review, we discuss the clinical relevance of genomic studies, particularly whole-genome sequencing, in the investigation of outbreaks. We also discuss the blurring of each of the three epidemiological groups (HA-MRSA, CA-MRSA and LA-MRSA), demonstrating the limited relevance of this classification. PMID:27530849

  14. MRSA as a health concern in athletic facilities.

    PubMed

    Hostetter, Karen S; Lux, Mary; Shelley, Kyna; Drummond, Jan L; Laguna, Patti

    2011-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a group of bacteria resistant to antibiotic treatment. Open abrasions, therapeutic whirlpools, treatment tables, locker rooms (LR), and athletic equipment are identified as potential areas of transmission in athletic training rooms (ATR) and LR facilities. To determine the prevalence of MRSA and to identify control measures in ATR and LR, the authors collected samples from nine surfaces at seven high schools over a four-month period. Initial analyses considered both suspected colonies and confirmed MRSA colonies with analyses of variance revealing significant differences of suspected colonies based on regular cleaning product and facility surface. Further results, however, focused on MRSA colonies as the primary variable, rather than suspected colonies. Results indicate a need for more effective cleaning products and schedules in LRs.

  15. Combating CA-MRSA in Physical Education, Sports, and Dance

    ERIC Educational Resources Information Center

    Andrews, Amanda K.; Howard-Shaughnessy, Candice; Adams, Jon E.

    2007-01-01

    By now most people have heard about the deadly bacteria that can fester in locker rooms, on sports equipment, and in dance facilities, among other places. This article was written to help PERD professionals become better informed about these bacteria, called community-acquired methicillin-resistant "Staphylococcus aureus" (CA-MRSA). Readers will…

  16. MRSA in a large German University Hospital: Male gender is a significant risk factor for MRSA acquisition

    PubMed Central

    Kupfer, Markus; Jatzwauk, Lutz; Monecke, Stephan; Möbius, Jana; Weusten, Axel

    2010-01-01

    Background: The continually rising number of hospital acquired infections and particularly MRSA (Methicillin-resistant Staphylococcus aureus) colonization poses a major challenge from both clinical and epidemiological perspectives. The assessment of risk factors is vital in determining the best prevention, diagnosis and treatment strategies. Materials and methods: We analyzed 798 cases of MRSA in a large German University Hospital over a 7-year period. Data was collected retro- and prospectively including patient age, sex, type of ward and duration of inpatient stay. In addition we analyzed all cases on ICU with regards to cross infection and MRSA genotyping via DNA MicroArray Technology. The years 2004 to 2007 were analyzed with a specific focus on gender. Results: Male gender is significantly correlated with increased risk of MRSA acquisition (p<0.001), the predominant setting for MRSA is on ICU. 75% of the MRSA positive patients are over 50 years of age (average age 59.8 years). The inpatient time was 4.15 times higher in MRSA carriers compared with non-MRSA cases, however this was not significant. MRSA genotyping on ICU showed mainly the subtypes ST 5, ST 22, ST 228, however cross contamination with identical genotypes was only detected in a minority of cases (5 out of 22). Conclusion: Unlike previous studies which show no or inconclusive evidence of gender as a risk factor, our data confirm that male gender is a significant risk factor for MRSA carrier status. Further research will be required to investigate the aetiology of these findings. PMID:20941335

  17. A case of MRSA controlled: predisposing factors and immune stimulation.

    PubMed

    Lamson, Davis W; Sadlon, Angela E

    2010-07-01

    Most treatments for methicillin-resistant Staphylococcus aureus (MRSA) focus on agents to eliminate the bacterium. Since MRSA infection is not universal, susceptibility factors are possible. Immune resistance could be lowered in such individuals; therefore, locating immune-inhibiting or immune-enhancing factors might decrease susceptibility. Such seemed to be the case in a 48-year-old female who presented with recurring MRSA despite multiple rounds of a variety of antibiotics. When the patient encountered an intensely stressful situation an outbreak of MRSA occurred. The patient had additional underlying health issues that suppressed her immune system and made her more susceptible to stress. Gluten allergy and hypothyroidism were discovered and alleviated but did not end the MRSA outbreaks. Implementation of a popular treatment from the 1930s, intravenous dilute hydrochloric acid (for immune stimulation), prevented most MRSA outbreaks when administered frequently. This case provides anecdotal support for the proposition that immune enhancement is a viable approach to forestall or clear recurring MRSA.

  18. Detection and genetic characterization of PVL-positive ST8-MRSA-IVa and exfoliative toxin D-positive European CA-MRSA-Like ST1931 (CC80) MRSA-IVa strains in Bangladesh.

    PubMed

    Paul, Shyamal Kumar; Ghosh, Souvik; Kawaguchiya, Mitsuyo; Urushibara, Noriko; Hossain, Mohammad Akram; Ahmed, Salma; Mahmud, Chand; Jilani, Md Shariful Alam; Haq, Jalaluddin Ashraful; Ahmed, Abdullah Akhtar; Kobayashi, Nobumichi

    2014-08-01

    Severe skin lesions caused by Staphylococcus aureus infection are associated with production from bacterial cells of Panton-Valentine leukocidin (PVL), a typical virulence factor of community-acquired methicillin-resistant S. aureus (CA-MRSA), as well as other toxins represented by exfoliative toxins. Through a retrospective study of 26 S. aureus strains isolated from skin lesions of diabetic patients admitted to a hospital in Bangladesh, 2 PVL-gene-positive MRSA-IVa strains and 8 PVL-negative, exfoliative toxin D (ETD) gene (etd)-positive MRSA-IVa strains were isolated. A PVL-positive MRSA-IVa strain had a type I arginine catabolic mobile element (ACME), belonged to ST8/agr-type I/spa-type t121 (a variant of t008), and harbored blaZ, tet(K), msrA, and aph(3')-IIIa, which are mostly typical characteristics found in USA300, a predominant CA-MRSA clone in the United States. Another PVL-positive MRSA strain, belonging to ST1929 (CC88)/agr-type III/spa-type t3341, was negative for ACME, but possessed blaZ and tet(K). The etd-positive MRSA-IVa strains possessed the epidermal cell differentiation inhibitor B (EDIN-B)-encoding gene (edinB) and belonged to ST1931 (CC80)/agr-type III/spa-type t11023 (a variant of t044), which was genetic trait similar to that of the European CA-MRSA ST80 clone. However, unlike the European ST80 strains, the etd-positive MRSA strains detected in the present study harbored seb, sek, and seq, while they were negative for tet(K), aph(3')-IIIa, and fusB, showing susceptibility to fusidic acid. These findings suggested that etd-positive ST1931 MRSA strains belong to the same lineage as the European ST80 MRSA clone, evolving from a common ancestral clone via acquisition of a different pathogenicity island. This is the first report of a USA300-like MRSA-IV strain, PVL-positive ST1929 (CC88) MRSA-IV, and European ST80 CA-MRSA-like etd-positive ST1931 (CC80) MRSA-IV strains isolated in Bangladesh.

  19. Response of Methicillin-Resistant Staphylococcus aureus to Amicoumacin A

    PubMed Central

    Chon, Tai; Wiersma, Anna M.; Sit, Clarissa S.; Vederas, John C.; Hecker, Michael; Nakano, Michiko M.

    2012-01-01

    Amicoumacin A exhibits strong antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA), hence we sought to uncover its mechanism of action. Genome-wide transcriptome analysis of S. aureus COL in response to amicoumacin A showed alteration in transcription of genes specifying several cellular processes including cell envelope turnover, cross-membrane transport, virulence, metabolism, and general stress response. The most highly induced gene was lrgA, encoding an antiholin-like product, which is induced in cells undergoing a collapse of Δψ. Consistent with the notion that LrgA modulates murein hydrolase activity, COL grown in the presence of amicoumacin A showed reduced autolysis, which was primarily caused by lower hydrolase activity. To gain further insight into the mechanism of action of amicoumacin A, a whole genome comparison of wild-type COL and amicoumacin A-resistant mutants isolated by a serial passage method was carried out. Single point mutations generating codon substitutions were uncovered in ksgA (encoding RNA dimethyltransferase), fusA (elongation factor G), dnaG (primase), lacD (tagatose 1,6-bisphosphate aldolase), and SACOL0611 (a putative glycosyl transferase). The codon substitutions in EF-G that cause amicoumacin A resistance and fusidic acid resistance reside in separate domains and do not bring about cross resistance. Taken together, these results suggest that amicoumacin A might cause perturbation of the cell membrane and lead to energy dissipation. Decreased rates of cellular metabolism including protein synthesis and DNA replication in resistant strains might allow cells to compensate for membrane dysfunction and thus increase cell survivability. PMID:22479511

  20. Methicillin resistant Staphylococcus aureus meningitis

    PubMed Central

    Pereira, Noella Maria Delia; Shah, Ira; Ohri, Alpana; Shah, Forum

    2015-01-01

    Methicillin resistant Staphylococcus aureus (MRSA) meningitis is rarely known to occur in children. We report an 11-year-old girl with fever, headache and vomiting, right hemiparesis with left-sided upper motor neuron facial nerve palsy and bladder incontinence. On investigation, she was found to have MRSA meningitis with an acute left thalamo-corpuscular infarct. She was treated with vancomycin, linezolid and rifampicin. She recovered successfully with residual right-sided lower limb monoparesis. MRSA meningitis is rare but can occur in children. PMID:26609421

  1. MRSA Prevention Information and Advice for Athletes

    MedlinePlus

    ... What to do If You Think You Have MRSA Tell your parent, coach, athletic trainer, school nurse, ... MRSA in athletic facilities... Top of Page Why MRSA is Spread among Athletes MRSA might spread easily ...

  2. Community Acquisition of Gentamicin-Sensitive Methicillin-Resistant Staphylococcus aureus in Southeast Queensland, Australia

    PubMed Central

    Nimmo, Graeme R.; Schooneveldt, Jacqueline; O'Kane, Gabrielle; McCall, Brad; Vickery, Alison

    2000-01-01

    Community-acquired methicillin-resistant Staphylococcus aureus (MRSA) susceptible to gentamicin has been reported in a number of countries in the 1990s. To study the acquisition of gentamicin-sensitive MRSA (GS-MRSA) in southeast Queensland and the relatedness of GS-MRSA to other strains of MRSA, 35 cases of infection due to GS-MRSA from October 1997 through September 1998 were examined retrospectively to determine the mode of acquisition and risk factors for MRSA acquisition. Thirty-one isolates from the cases were examined using a variety of methods (antibiotyping, phage typing, pulsed-field gel electrophoresis [PFGE] fingerprinting, and coagulase typing by restriction analysis of PCR products) and were compared with strains of local hospital-acquired gentamicin-resistant MRSA (GR-MRSA) and of Western Australian MRSA (WA-MRSA). Only 6 of 23 cases of community-acquired GS-MRSA had risk factors for MRSA acquisition. Twenty of 21 isolates from cases of community-acquired infection were found to be related by PFGE and coagulase typing and had similar phage typing patterns. Hospital- and nursing home-acquired GS-MRSA strains were genetically and phenotypically diverse. Community-acquired GS-MRSA strains were not related to nosocomial GR-MRSA or WA-MRSA, but phage typing results suggest that they are related to GS-MRSA previously reported in New Zealand. PMID:11060046

  3. Community-based intervention to manage an outbreak of MRSA skin infections in a county jail.

    PubMed

    Elias, Abdallah F; Chaussee, Michael S; McDowell, Emily J; Huntington, Mark K

    2010-07-01

    This article describes a community-based intervention to manage an outbreak of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) skin infections in a midwestern county jail. A systematic investigation conducted by a family medicine residency program identified 64 total cases and 19 MRSA cases between January 1 and December 31, 2007. Factors contributing to MRSA transmission included inadequate surveillance, lack of antibacterial soap, and a defective laundry process. All 19 isolates were CA-MRSA and all seven tested by pulsed-field gel electrophoresis (PFGE) were USA300. Four of the seven isolates showed variation of their PFGE patterns. A primary care approach using community-based resources effectively reduced the number of cases in this heterogeneous outbreak of CA-MRSA, with the last MRSA being isolated in October 2007. PMID:20466702

  4. Structural and functional analysis of betaine aldehyde dehydrogenase from Staphylococcus aureus.

    PubMed

    Halavaty, Andrei S; Rich, Rebecca L; Chen, Chao; Joo, Jeong Chan; Minasov, George; Dubrovska, Ievgeniia; Winsor, James R; Myszka, David G; Duban, Mark; Shuvalova, Ludmilla; Yakunin, Alexander F; Anderson, Wayne F

    2015-05-01

    When exposed to high osmolarity, methicillin-resistant Staphylococcus aureus (MRSA) restores its growth and establishes a new steady state by accumulating the osmoprotectant metabolite betaine. Effective osmoregulation has also been implicated in the acquirement of a profound antibiotic resistance by MRSA. Betaine can be obtained from the bacterial habitat or produced intracellularly from choline via the toxic betaine aldehyde (BA) employing the choline dehydrogenase and betaine aldehyde dehydrogenase (BADH) enzymes. Here, it is shown that the putative betaine aldehyde dehydrogenase SACOL2628 from the early MRSA isolate COL (SaBADH) utilizes betaine aldehyde as the primary substrate and nicotinamide adenine dinucleotide (NAD(+)) as the cofactor. Surface plasmon resonance experiments revealed that the affinity of NAD(+), NADH and BA for SaBADH is affected by temperature, pH and buffer composition. Five crystal structures of the wild type and three structures of the Gly234Ser mutant of SaBADH in the apo and holo forms provide details of the molecular mechanisms of activity and substrate specificity/inhibition of this enzyme.

  5. Structural and functional analysis of betaine aldehyde dehydrogenase from Staphylococcus aureus

    PubMed Central

    Halavaty, Andrei S.; Rich, Rebecca L.; Chen, Chao; Joo, Jeong Chan; Minasov, George; Dubrovska, Ievgeniia; Winsor, James R.; Myszka, David G.; Duban, Mark; Shuvalova, Ludmilla; Yakunin, Alexander F.; Anderson, Wayne F.

    2015-01-01

    When exposed to high osmolarity, methicillin-resistant Staphylococcus aureus (MRSA) restores its growth and establishes a new steady state by accumulating the osmoprotectant metabolite betaine. Effective osmoregulation has also been implicated in the acquirement of a profound antibiotic resistance by MRSA. Betaine can be obtained from the bacterial habitat or produced intracellularly from choline via the toxic betaine aldehyde (BA) employing the choline dehydrogenase and betaine aldehyde dehydrogenase (BADH) enzymes. Here, it is shown that the putative betaine aldehyde dehydrogenase SACOL2628 from the early MRSA isolate COL (SaBADH) utilizes betaine aldehyde as the primary substrate and nicotinamide adenine dinucleotide (NAD+) as the cofactor. Surface plasmon resonance experiments revealed that the affinity of NAD+, NADH and BA for SaBADH is affected by temperature, pH and buffer composition. Five crystal structures of the wild type and three structures of the Gly234Ser mutant of SaBADH in the apo and holo forms provide details of the molecular mechanisms of activity and substrate specificity/inhibition of this enzyme. PMID:25945581

  6. [Effect of methylrosanilinium chloride to MRSA nasal carriers].

    PubMed

    Ogino, J; Murakami, Y; Yamada, T

    1992-03-01

    Since the end of 1987, we have noticed an increasing incidence of Methicillin resistant Staphylococcus aureus (MRSA) among the inpatients of Yamanashi Medical College Hospital. MRSA strains were identified in 70-80 percent of the specimens obtained from patients with Staphylococcus aureus. From 1988 we performed yearly bacteriological examinations of the nares of medical personnel at Yamanashi Medical College Hospital. We treated nasal carriers with OFLX drop lotion or Povidone-iodine applied to the nares. In 1991 we treated eight nasal carriers, who had been unsuccessfully treated with Povidone-iodine, with 0.01% Methylrosanilinium Chloride ointment which was applied to the nares once a day for two weeks. A post-bacteriological examination again revealed that MRSA vanished from the nares of six nasal carriers. The minimum inhibitory concentration (MIC) of Methylrosanilinium Chloride was determined by the agar plate dilution method. The 100% MICs of MSSA were 1.0 microgram/ml and of MRSA were 1.0 microgram/ml by Methylrosanilinium Chloride. Moreover we examined the MICs of Methylrosanilinium Chloride against MRSA under the existing 5% Albumin, and consequently the 100% MICs were 4.0 micrograms/ml. Therefore a 0.01% Methylrosanilinium Chloride has sufficient efficacy against MRSA. The reaction of the skin and nasal mucosa to Methylrosanilinium Chloride was examined by using three groups of guinea pigs. 0.1% and 0.01% Methylrosanilinium Chloride ointment and hydrophylic poloid were applied to the nares and skin once a day for two weeks. Post-observation with an opticmicroscope revealed no significant findings. Methylrosanilinium Chloride shows good anti-Staphylococcus aureus ability. Further investigation is needed to determine if Methylrosanilinium Chloride has additional clinical application.

  7. Detection of methicillin-resistant Staphylococcus aureus in clinical specimens from cystic fibrosis patients by use of chromogenic selective agar.

    PubMed

    Perez, Leandro Reus Rodrigues; Antunes, Ana Lúcia Souza; Bonfanti, Jéssica Weiss; Pinto, Jaqueline Becker; Roesch, Eliane Wurdig; Rodrigues, Diógenes; Dias, Cícero Armídio Gomes

    2012-07-01

    We evaluated the use of a chromogenic selective medium (MRSA ID) as a useful tool for the detection of methicillin-resistant Staphylococcus aureus (MRSA) in cystic fibrosis (CF) patient samples. Fifty-four MRSA isolates were detected by MRSA ID, while only 24/54 (44%) (odds ratio [OR], 2.79; 95% confidence interval [CI], 1.63 to 4.76) were detected by conventional methods. A chromogenic selective medium for MRSA detection may improve its surveillance in CF patients.

  8. Superimposed MRSA infection of vulvar eczematous dermatitis

    PubMed Central

    Carey, Erin; Zedek, Daniel; Lewis, Jasmine; Zolnoun, Denniz

    2014-01-01

    Background Vulvar eczematous dermatitis predisposes patients to superimposed infections, which may result in late diagnosis and architectural destruction. Methicillin resistant staphylococcus aureus (MRSA) infection is on the rise in genitalia and lower extremities. Case 44 year-old female presented with recurrent vulvar lesions and pain. A diagnosis of methicillin resistant staphylococcus aureus in the setting of eczema was achieved with concomitant use of photography and dermatopathologic review. Antibiotics were tailored to the resistant infection and preventative moisturization therapy was utilized. Conclusion Awareness of dermatologic conditions affecting the vulva is principal in routine gynecologic care. Barrier protection of eczematous vulvar skin may prevent superficial infections. The regular use of photographic documentation and dermatopathology may decrease time to diagnosis with infrequent conditions. PMID:23763013

  9. Amoxicillin functionalized gold nanoparticles reverts MRSA resistance.

    PubMed

    Kalita, Sanjeeb; Kandimalla, Raghuram; Sharma, Kaustav Kalyan; Kataki, Amal Chandra; Deka, Manab; Kotoky, Jibon

    2016-04-01

    In this study, we have described the biosynthesis of biocompatible gold nanoparticles (GNPs) from aqueous extract of the aerial parts of a pteridophyte, "Adiantum philippense" by microwave irradiation and its surface functionalization with broad spectrum beta lactam antibiotic, amoxicillin (Amox). The functionalization of amoxicillin on GNPs (GNP-Amox) was carried out via electrostatic interaction of protonated amino group and thioether moiety mediated attractive forces. The synthesized GNPs and GNP-Amox were physicochemically characterized. UV-Vis spectroscopy, Zeta potential, XRD, FTIR and SERS (surface enhanced raman spectra) results confirmed the loading of Amox into GNPs. Loading of Amox to GNPs reduce amoxicillin cytotoxicity, whereas GNPs were found to be nontoxic to mouse fibroblast cell line (L929) as evident from MTT and acridine orange/ethidium bromide (AO/EtBr) live/dead cell assays. The GNP-Amox conjugates demonstrated enhanced broad-spectrum bactericidal activity against both Gram-positive and Gram-negative bacteria. Furthermore, in-vitro and in-vivo assays of GNP-Amox revealed potent anti-MRSA activity and improved the survival rate. This indicates the subversion of antibiotic resistance mechanism by overcoming the effect of high levels of β-lactamase produced by methicillin resistant Staphylococcus aureus (MRSA). Taken together, this study demonstrates the positive attributes from GNP-Amox conjugates as a promising antibacterial therapeutic agent against MRSA as well as other pathogens.

  10. Coagulase-negative staphylococci as reservoirs of genes facilitating MRSA infection

    PubMed Central

    Otto, Michael

    2013-01-01

    Recent research has suggested that Staphylococcus epidermidis is a reservoir of genes that, after horizontal transfer, facilitate the potential of Staphylococcus aureus to colonize, survive during infection, or resist antibiotic treatment, traits that are notably manifest in methicillin-resistant S. aureus (MRSA). S. aureus is a dangerous human pathogen and notorious for acquiring antibiotic resistance. MRSA in particular is one of the most frequent causes of morbidity and death in hospitalized patients. S. aureus is an extremely versatile pathogen with a multitude of mechanisms to cause disease and circumvent immune defenses. In contrast, most other staphylococci, such as S. epidermidis, are commonly benign commensals and only occasionally cause disease. Recent findings highlight the key importance of efforts to better understand how genes of staphylococci other than S. aureus contribute to survival in the human host, how they are transferred to S. aureus, and why this exchange appears to be uni-directional. PMID:23165978

  11. Preventing Community-Associated Methicillin-Resistant "Staphylococcus aureus" among Student Athletes

    ERIC Educational Resources Information Center

    Many, Patricia S.

    2008-01-01

    Methicillin-resistant "Staphylococcus aureus" (MRSA) was once thought to be a bacterium causing infections in only hospitalized patients. However, a new strain of MRSA has emerged among healthy individuals who have not had any recent exposure to a hospital or to medical procedures. This new strain is known as "community-associated MRSA". Studies…

  12. Staphylococcus aureus induces hypoxia and cellular damage in porcine dermal explants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methicillin-resistant Staphylococcus aureus (MRSA) can infect wounds and produce difficult-to- treat biofilms. To determine the extent that MRSA biofilms can deplete oxygen, change pH and damage host tissue, we developed a porcine dermal explant model on which we cultured GFP-labeled MRSA biofilms. ...

  13. Carriage of methicillin-resistant Staphylococcus aureus by healthy companion animals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methicillin-resistant Staphylococcus aureus (MRSA) is a significant human pathogen and has also been associated with wounded or ill companion animals. Healthy animals may also harbor MRSA without presenting any symptoms, but little is known about the prevalence of MRSA among these animals. Therefo...

  14. Methicillin-Resistant Staphylococcus aureus Prevalence among Captive Chimpanzees, Texas, USA, 20121

    PubMed Central

    Barnhart, Kirstin F.; Abee, Christian R.; Lambeth, Susan P.; Weese, J. Scott

    2015-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) infection in humans and animals is concerning. In 2012, our evaluation of a captive chimpanzee colony in Texas revealed MRSA prevalence of 69%. Animal care staff should be aware of possible zoonotic MRSA transmission resulting from high prevalence among captive chimpanzees. PMID:26583847

  15. Methicillin-Resistant Staphylococcus aureus Prevalence among Captive Chimpanzees, Texas, USA, 2012(1).

    PubMed

    Hanley, Patrick W; Barnhart, Kirstin F; Abee, Christian R; Lambeth, Susan P; Weese, J Scott

    2015-12-01

    Methicillin-resistant Staphylococcus aureus (MRSA) infection in humans and animals is concerning. In 2012, our evaluation of a captive chimpanzee colony in Texas revealed MRSA prevalence of 69%. Animal care staff should be aware of possible zoonotic MRSA transmission resulting from high prevalence among captive chimpanzees.

  16. Methicillin resistant S. aureus in human and bovine mastitis.

    PubMed

    Holmes, Mark A; Zadoks, Ruth N

    2011-12-01

    Staphylococcus aureus is a ubiquitous organism that causes a variety of diseases including mastitis in cattle and humans. High-level resistance of S. aureus to β-lactams conferred by a mecA gene encoding a modified penicillin binding protein (PBP2a) was first observed in the early 1960's. These methicillin resistant S. aureus (MRSA) have been responsible for both hospital acquired infections (HA-MRSA) and, more recently, community acquired MRSA (CA-MRSA). A small number of human MRSA mastitis cases and outbreaks in maternity or neonatal units have been reported which are generally the result of CA-MRSA. The establishment of the sequence type 398 (ST398) in farm animals, primarily pigs, in the early 2000's has provided a reservoir of infection for humans and dairy cattle, particularly in continental Europe, described as livestock-associated MRSA (LA-MRSA). Prior to the emergence of ST398 there were sporadic reports of MRSA in bovine milk and cases of mastitis, often caused by strains from human associated lineages. Subsequently, there have been several reports describing bovine udder infections caused by ST-398 MRSA. Recently, another group of LA-MRSA strains was discovered in humans and dairy cattle in Europe. This group carries a divergent mecA gene and includes a number of S. aureus lineages (CC130, ST425, and CC1943) that were hitherto thought to be bovine-specific but are now also found as carriage or clinical isolates in humans. The emergence of MRSA in dairy cattle may be associated with contact with other host species, as in the case of ST398, or with the exchange of genetic material between S. aureus and coagulase negative Staphylococcus species, which are the most common species associated with bovine intramammary infections and commonly carry antimicrobial resistance determinants.

  17. An Ex Vivo Porcine Nasal Mucosa Explants Model to Study MRSA Colonization

    PubMed Central

    Tulinski, Pawel; Fluit, Ad C.; van Putten, Jos P. M.; de Bruin, Alain; Glorieux, Sarah; Wagenaar, Jaap A.; Duim, Birgitta

    2013-01-01

    Staphylococcus aureus is an opportunistic pathogen able to colonize the upper respiratory tract and skin surfaces in mammals. Methicillin-resistant S. aureus ST398 is prevalent in pigs in Europe and North America. However, the mechanism of successful pig colonization by MRSA ST398 is poorly understood. To study MRSA colonization in pigs, an ex vivo model consisting of porcine nasal mucosa explants cultured at an air-liquid interface was evaluated. In cultured mucosa explants from the surfaces of the ventral turbinates and septum of the pig nose no changes in cell morphology and viability were observed up to 72 h. MRSA colonization on the explants was evaluated followed for three MRSA ST398 isolates for 180 minutes. The explants were incubated with 3×108 CFU/ml in PBS for 2 h to allow bacteria to adhere to the explants surface. Next the explants were washed and in the first 30 minutes post adhering time, a decline in the number of CFU was observed for all MRSA. Subsequently, the isolates showed either: bacterial growth, no growth, or a further reduction in bacterial numbers. The MRSA were either localized as clusters between the cilia or as single bacteria on the cilia surface. No morphological changes in the epithelium layer were observed during the incubation with MRSA. We conclude that porcine nasal mucosa explants are a valuable ex vivo model to unravel the interaction of MRSA with nasal tissue. PMID:23326505

  18. [EUREGIO-projekt MRSA-net Twente/Münsterland. Creation of a regional network to combat MRSA].

    PubMed

    Daniels-Haardt, I; Verhoeven, F; Mellmann, A; Hendrix, M G R; Gemert-Pijnen, J E C; Friedrich, A W

    2006-11-01

    Over the last years, Germany has observed an increase in the prevalence of methicillin-resistant Staphylococcus (MRSA) in all S. aureus isolates from 2 % to about 25 % whereas in The Netherlands this proportion has continuously been kept below 1 % thanks to a consistent "search & destroy" policy. Both countries increasingly register so-called community-acquired (CA) MRSA which are a threat also to the healthy population without any known risk factor for MRSA carriership. The EUREGIO project "MRSA-net Twente/Münsterland" has made it its main goal to set up a German-Dutch network serving as a basis for a quality association which includes all those who are actively involved in health care provision on both sides of the border and to implement a coordinated strategy for MRSA control and prevention. The project is being carried out with the financial support of the European Union under the INTERREG-IIIA Community initiative and of the Ministry of Economics of the State of North Rhine-Westphalia. The epidemiological backbone of the MRSA-net is a genetic-based MRSA typing strategy (spa-typing) which has been developed by the Institute for Hygiene, University Hospital, Münster and which allows regional and cross-border comparability of laboratory results. The Faculty of Behavioural Sciences of the University of Twente examines MRSA hygiene protocols with regard to their acceptability and realisability with the intention of developing user-friendly, target group-oriented MRSA protocols for the EUREGIO. The health departments involved in the project play a central role in the coordination of the network partners in the municipalities. By performing their function of surveillance in accordance with Sections 23 and 36 of the Infectious Disease Control Act they provide an important contribution to enhancing MRSA control and prevention strategies. Thanks to its cross-border cooperation and exchange of knowledge and technology the EUREGIO project "MRSA-net" contributes to

  19. Combined Use of Pastorex Staph-Plus and Either of Two New Chromogenic Agars, MRSA ID and CHROMagar MRSA, for Detection of Methicillin-Resistant Staphylococcus aureus▿

    PubMed Central

    Compernolle, Veerle; Verschraegen, Gerda; Claeys, Geert

    2007-01-01

    We describe the search toward a fast and reliable strategy to detect and confirm the presence of methicillin-resistant Staphylococcus aureus (MRSA) in screening samples. First, we evaluated the sensitivities and specificities of oxacillin resistance screening agar (ORSA) with enrichment (tryptic soy broth [TSB] and ORSA [TSB-ORSA]) and without enrichment (ORSA), MRSA ID (MRSA_ID) plates, and CHROMagar MRSA (C_MRSA) plates, all of which were inoculated with equal volumes of a suspension made by emulsifying screening swabs. Whereas the sensitivities after 48 h were similar for all media tested (77% for MRSA_ID and ORSA; 73% for C_MRSA and ORSA after enrichment [TSB-ORSA]), the specificities of MRSA_ID (98% after 24 h and 94% after 48 h) and C_MRSA (98% after 24 h and 90% after 48 h) were superior to the specificities of ORSAs (92% after 24 h and 83% after 48 h) and TSB-ORSA (86% after 24 h and 81% after 48 h). Subsequently, the performance of the Pastorex Staph-Plus agglutination test with presumptive MRSA isolates taken directly from chromogenic agars (direct_Pastorex agglutination) was compared to that of the Pastorex Staph-Plus agglutination test with isolates from blood agar subcultures (conventional_Pastorex agglutination). When the direct_Pastorex agglutination test on MRSA_ID plates was combined with Gram staining, the direct_Pastorex agglutination test with samples from MRSA_ID plates was as reliable as the conventional_Pastorex agglutination test with samples from blood agar subcultures from MRSA_ID plates. In contrast, the direct_Pastorex agglutination test with samples from C_MRSA plates gave false-negative results. Finally, we calculated the processing times of the four different strategies, namely, (i) enrichment in TSB supplemented with NaCl, subsequent culture on ORSA, and the conventional_Pastorex agglutination test; (ii) direct inoculation of ORSA combined with conventional_Pastorex agglutination test; (iii) direct inoculation of MRSA_ID plates

  20. Comparative prevalence of immune evasion complex genes associated with beta-hemolysin converting bacteriophages in MRSA ST5 isolates from swine, swine facilities, humans with swine contact, and humans with no swine contact

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Livestock associated methicillin-resistant Staphylococcus aureus (LA-MRSA) draws concern from the public health community because in some countries these organisms may represent the largest reservoir of MRSA outside hospital settings. Recent studies indicate LA-MRSA strains from swine are more genet...

  1. First report of infection with community-acquired methicillin-resistant Staphylococcus aureus in South America.

    PubMed

    Ribeiro, Apoena; Dias, Cícero; Silva-Carvalho, Maria Cícera; Berquó, Laura; Ferreira, Fabienne Antunes; Santos, Raquel Neves Soares; Ferreira-Carvalho, Bernadete Teixeira; Figueiredo, Agnes Marie

    2005-04-01

    Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) has recently emerged in the southwestern Pacific, North America, and Europe. These S. aureus isolates frequently shared some genetic characteristics, including the SCCmec type IV and lukS-lukF genes. In this paper we show that typical CA-MRSA isolates have spread to South America (Brazil).

  2. Advances in MRSA drug discovery: where are we and where do we need to be?

    PubMed Central

    Kurosu, Michio; Siricilla, Shajila; Mitachi, Katsuhiko

    2013-01-01

    Introduction Methicillin-resistant Staphylococcus aureus (MRSA) have been on the increase during the past decade, due to the steady growth of the elderly and immunocompromised patients, and the emergence of multi-drug-resistant (MDR) bacterial strains. Although, only a limited number of anti-MRSA drugs are available, a number of different combination antimicrobial drug regimens have been used to treat serious MRSA infections. Thus, addition of several new antistaphylococcal drugs into clinical practice should broaden therapeutic options. Because MRSA is one of the most common and problematic bacteria associated with increasing antimicrobial resistance, continuous efforts on discovery of lead compounds as well as development of alternative therapies and faster diagnostics to ensure effective antistaphylococcal therapy are required. Areas covered This article summarizes the FDA approved drugs to treat MRSA infections, the drugs in clinical trials, and the drug leads for MRSA and related Gram-positive bacterial infections. In addition, the mode of action of antistaphylococcal molecules and resistant mechanisms of some molecules are briefly discussed. Expert opinion The number of pipeline drugs presently undergoing clinical trials is not particularly encouraging. There are limited and rather expensive therapeutic options for the infections by MRSA in the critically ill. This review article provides an update on antistaphylococcal drugs in clinical trials and antibacterial molecules effective against Gram-positive bacteria including MRSA. The structural and biological information of antibacterials summarized here are very useful for designing drug leads to develop into new anti-MRSA drugs. PMID:23829425

  3. Intrarenal abscess caused by community-associated methicillin-resistant Staphylococcus aureus in a transplanted kidney.

    PubMed

    Cheung, C Y; Chan, S Y; Yeung, C S; Kwok, P C; Chak, W L; Wu, T C; Chau, K F

    2016-04-01

    Emergence of multidrug-resistant bacteria is important in solid organ transplant recipients, because it can jeopardize patient and graft survival. Methicillin-resistant Staphylococcus aureus (MRSA) infections are not rare in kidney transplant recipients. On the other hand, infections related to community-associated MRSA (CA-MRSA) strains are seldom reported in the literature. Herein, we report the first patient, to our knowledge, with CA-MRSA renal graft abscess who was successfully treated with drainage and parenteral antibiotics.

  4. A novel nitro-dexamethasone inhibits agr system activity and improves therapeutic effects in MRSA sepsis models without antibiotics

    PubMed Central

    Yang, Yun; Li, Haibo; Sun, Hongwu; Gong, Li; Guo, Ling; Shi, Yun; Cai, Changzhi; Gu, Hao; Song, Zhen; Yang, Liuyang; Tong, Yanan; Wei, Chao; Zou, Quanming; Zeng, Hao

    2016-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) sepsis is a life-threatening medical condition that involves systemic inflammation throughout the body. Glucocorticoids are widely used in combination with antibiotics in the treatment of MRSA sepsis to fight the overwhelming inflammation. Here, we describe the improved anti-inflammatory properties of a nitric oxide (NO)-releasing derivative of dexamethasone, ND8008. ND8008 affected MRSA biofilm formation, caused biofilm cell death, and reduced the effects of virulence factors, such as α-toxin, by inhibiting the activity of the Staphylococcus aureus accessory gene regulator (agr) system. Dosing of mice with ND8008 (127.4 nmol/kg, i.p.) alone greatly reduced the inflammatory response caused by MRSA blood stream infection and considerably increased the survival rate of septic mice. These findings suggest that this novel NO-releasing derivative of dexamethasone ND8008 could be helpful in the treatment of MRSA sepsis. PMID:26839286

  5. Analysis of Transmission of MRSA and ESBL-E among Pigs and Farm Personnel.

    PubMed

    Schmithausen, Ricarda Maria; Schulze-Geisthoevel, Sophia Veronika; Stemmer, Franziska; El-Jade, Mohamed; Reif, Marion; Hack, Sylvia; Meilaender, Alina; Montabauer, Gabriele; Fimmers, Rolf; Parcina, Marijo; Hoerauf, Achim; Exner, Martin; Petersen, Brigitte; Bierbaum, Gabriele; Bekeredjian-Ding, Isabelle

    2015-01-01

    Livestock-associated bacteria with resistance to two or more antibiotic drug classes have heightened our awareness for the consequences of antibiotic consumption and spread of resistant bacterial strains in the veterinary field. In this study we assessed the prevalence of concomitant colonization with livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) and enterobacteriaceae expressing extended-spectrum betalactamases (ESBL-E) in farms at the German-Dutch border region. Nasal colonization of pigs with MRSA (113/547 (20.7%)) was less frequent than rectal colonization with ESBL-E (163/540 (30.2%)). On the individual farm level MRSA correlated with ESBL-E recovery. The data further provide information on prevalence at different stages of pig production, including abattoirs, as well as in air samples and humans living and working on the farms. Notably, MRSA was detected in stable air samples of 34 out of 35 pig farms, highlighting air as an important MRSA transmission reservoir. The majority of MRSA isolates, including those from humans, displayed tetracycline resistance and spa types t011 and t034 characteristic for LA-MRSA, demonstrating transmission from pigs to humans. ESBL-E positive air samples were detected on 6 out of 35 farms but no pig-to-human transmission was found. Detection of ESBL-E, e.g. mostly Escherichia coli with CTX-M-type ESBL, was limited to these six farms. Molecular typing revealed transmission of ESBL-E within the pig compartments; however, related strains were also found on unrelated farms. Although our data suggest that acquisition of MRSA and ESBL-E might occur among pigs in the abattoirs, MRSA and ESBL-E were not detected on the carcasses. Altogether, our data define stable air (MRSA), pig compartments (ESBL-E) and abattoir waiting areas (MRSA and ESBL-E) as major hot spots for transmission of MRSA and/or ESBL-E along the pig production chain.

  6. Thiol activated prodrugs of sulfur dioxide (SO2) as MRSA inhibitors.

    PubMed

    Pardeshi, Kundansingh A; Malwal, Satish R; Banerjee, Ankita; Lahiri, Surobhi; Rangarajan, Radha; Chakrapani, Harinath

    2015-07-01

    Drug resistant infections are becoming common worldwide and new strategies for drug development are necessary. Here, we report the synthesis and evaluation of 2,4-dinitrophenylsulfonamides, which are donors of sulfur dioxide (SO2), a reactive sulfur species, as methicillin-resistant Staphylococcus aureus (MRSA) inhibitors. N-(3-Methoxyphenyl)-2,4-dinitro-N-(prop-2-yn-1-yl)benzenesulfonamide (5e) was found to have excellent in vitro MRSA inhibitory potency. This compound is cell permeable and treatment of MRSA cells with 5e depleted intracellular thiols and enhanced oxidative species both results consistent with a mechanism involving thiol activation to produce SO2. PMID:25981687

  7. Prevalence and Risk Factor Analysis for Methicillin-Resistant Staphylococcus aureus Nasal Colonization in Children Attending Child Care Centers▿

    PubMed Central

    Miller, Melissa B.; Weber, David J.; Goodrich, Jennifer S.; Popowitch, Elena B.; Poe, Michele D.; Nyugen, Viet; Shope, Timothy R.; Foster, David T.; Miller, James R.; Kotch, Jonathan

    2011-01-01

    Children attending child care centers (CCCs) are at increased risk for infections, including those caused by methicillin-resistant Staphylococcus aureus (MRSA). Nasal colonization often precedes infection, and MRSA colonization has been associated with increased infection risk. Community-associated MRSA (CA-MRSA) has caused increased MRSA infections in the general population, including children. Little is known about the frequency of MRSA nasal colonization in young children, particularly in those attending CCCs where disease transmission is common. We sampled the nares of 1,163 children in 200 classrooms from 24 CCCs in North Carolina and Virginia to assess S. aureus colonization. MRSA strains were molecularly analyzed for staphylococcal cassette chromosome mec (SCCmec) type, Panton-Valentine leukocidin status, and multilocus sequence type. A case-control study was performed to identify risk factors for MRSA colonization. We found that 18.1% children were colonized with S. aureus and 1.3% with MRSA. Molecular analysis of the MRSA strains identified 47% as CA-MRSA and 53% as health care-associated MRSA (HA-MRSA). Although two centers had multiple children colonized with MRSA, genotyping indicated that no transmission had occurred within classrooms. The case-control study did not detect statistically significant risk factors for MRSA colonization. However, MRSA-colonized children were more likely to be nonwhite and to have increased exposure to antibiotics and skin infections in the home. Both CA-MRSA and HA-MRSA strains were found colonizing the nares of children attending CCCs. The low frequency of colonization observed highlights the need for a large multicenter study to determine risk factors for MRSA colonization and subsequent infection in this highly susceptible population. PMID:21191058

  8. Personal hygiene and methicillin-resistant Staphylococcus aureus infection.

    PubMed

    Turabelidze, George; Lin, Mei; Wolkoff, Barbara; Dodson, Douglas; Gladbach, Stephen; Zhu, Bao-Ping

    2006-03-01

    Methicillin-resistant Staphylococcus aureus (MRSA) infections outside the healthcare setting are an increasing concern. We conducted a case-control study to investigate an MRSA outbreak during 2002-2003 in a Missouri prison and focused on hygiene factors. Information on sociodemographic characteristics, medical history, and hygiene practices of study participants was collected by interview and medical record review. Logistic regression was used to evaluate MRSA infection in relation to hygiene factors individually and as a composite hygiene score; potential confounding factors were controlled. Selected MRSA isolates were analyzed by pulsed-field gel electrophoresis (PFGE). MRSA infection was significantly associated with a low composite hygiene score. Transmission among prison inmates appeared to be responsible for this outbreak. PFGE analysis showed that isolates were indistinguishable and associated with community-onset MRSA infections in other US prisons. Improving hygiene practices and environmental conditions may help prevent and interrupt future MRSA outbreaks in prison settings. PMID:16704779

  9. A model for surveillance of methicillin-resistant Staphylococcus aureus.

    PubMed

    Simons, Hannah; Alcabes, Philip

    2008-01-01

    It is well recognized that methicillin-resistant Staphylococcus aureus (MRSA) has become a community pathogen. Several key differences between community-associated and hospital-associated MRSA strains exist, including distinct methicillin resistance genes and genetic backgrounds and differing susceptibility to antibiotics. Recent studies have demonstrated that typical hospital and community strains easily move between hospital and community environments. Despite evidence of MRSA's expanding reach in the community, the best methods for population-level detection and containment have not been established. In an effort to determine effective methods for monitoring the spread of MRSA, we reviewed the literature on hospital-associated and community-associated MRSA (CA-MRSA) in the community and proposed a model for enhanced surveillance. By linking epidemiologic and molecular techniques within a surveillance system that coordinates activities in the community and health-care setting, scientists and public health officials can begin to measure the true extent of CA-MRSA in communities and hospitals.

  10. PEGylated liposomal vancomycin: a glimmer of hope for improving treatment outcomes in MRSA pneumonia.

    PubMed

    Pumerantz, Andrew S

    2012-12-01

    Methicillin-resistant Staphylococcus aureus (MRSA) plays a significant role in the pandemic of multidrug resistant bacterial infections and is a major cause of hospital-acquired pneumonia. MRSA pneumonia carries a high morbidity and mortality rate especially in elderly diabetics with chronic kidney disease. S. aureus is highly virulent and successful respiratory pathogen. Vancomycin and linezolid are the only two antimicrobial agents FDA-approved to treat MRSA pneumonia. Standard vancomycin dosing is associated with high clinical failure rates and higher dosages are associated with increased nephrotoxicity. Pharmacokinetic and pharmacodynamic limitations are major contributors to poor outcomes with vancomycin. New agents are needed to improve treatment outcomes with MRSA pneumonia. Recently released antimicrobials with in vitro activity are not FDA-approved for treating MRSA pneumonia. Other novel agents are being investigated though none are in late-stage development. Pharmaceutical industry perception of low returns on investment, a Sisyphean regulatory environment, and obstacles to patentability have contributed to declining interest in both the development of novel antibiotics and the improvement of existing generic formulations. Despite decades of investigation into liposomal encapsulation as a drug delivery system that would increase efficacy and decrease toxicity, only liposomal amphotericin B and doxorubicin are commercially available. In this article, the pharmacokinetics and biodistribution of a novel PEGylated liposomal vancomycin formulation along with passive targeting and the enhanced permeability and retention effect of liposomal drug delivery; the pathogenesis of MRSA pneumonia; and recent patents of novel anti-MRSA agents, including inhalational liposomal vancomycin, are reviewed. PMID:22742394

  11. [MRSA clones identified in outpatient dermatology clinics].

    PubMed

    Hosoya, Shino; Ito, Teruyo; Misawa, Shigeki; Yoshiike, Takashi; Oguri, Toyoko; Hiramatsu, Keiichi

    2014-11-01

    To know the characteristics of methicillin-resistant Staphylococcus aureus (MRSA) strains disseminating through the Japanese community, we have determined types of Staphylococcal cassette chromosome mec (SCCmec) elements, Multi-Locus Sequence Typing (MLST), and carriages of four exotoxin genes (toxic-shock syndrome toxin, Panton-Valentine Leukocidine, and exfoliative toxins a and b) using 54 MRSA strains isolated from outpatients attending dermatology clinics at the four university hospitals of Juntendo University. Ten clonal complexes and 12 SCCmec types have been identified. As a result, more than 15 MRSA clones that were defined by the combination of genotype and SCCmec type, were identified. Among them, Clonal Complex (CC) 5-type IIa SCCmec strains were the most major (16 strains). In contrast to the fact that CC5- type IIa SCCmec strains known as a hospital-associated MRSA clone in Japan carried toxic-shock syndrome toxin gene (tst), only 2 of 16 strains have been shown to carry tst. Thirty-eight (70.4%) of isolates belonged to the clones distinct from the CC5-type IIa SCCmec strains. Among them, CC8 strains were major (12 strains), which contained 9 tst-positive CC8-type IVl SCCmec clones and a CC8-type IVa SCCmec strain carrying the Panton Valentine Leukocidin gene (lukS, F-PV). Clones related to impetigo were also identified: 7 exfoliative toxin b (etb) -positive clones, CC89-type IIa SCCmec and CC89-type V SCCmec strains; and 2 exfoliative toxin a (eta) -positive CC121-type V SCCmec strains. Other clones were as follows: CC1-type IVa SCCmec, CC8-type I SCCmec, CC81-type IVg SCCmec, CC97-type IVc SCCmec, CC91-type IVa SCCmec, CC59-type IVg SCCmec, CC45-type IIn SCCmec, CC89-SCCmec nontypeable, and CC8-type IVm, novel subtype of type IV SCCmec were identified in this study. Our data showed that many novel MRSA clones have emerged in the community. PMID:25764806

  12. Staphylococcus aureus nasal carriage in the community: a survey from central Italy.

    PubMed Central

    Zanelli, G.; Sansoni, A.; Zanchi, A.; Cresti, S.; Pollini, S.; Rossolini, G. M.; Cellesi, C.

    2002-01-01

    Recently, concern has increased regarding the spread of methicillin-resistant Staphylococcus aureus (MRSA) in the community. We studied 812 subjects from central Italy to establish the rates of nasal carriage of S. aureus, and antibiotic susceptibility patterns, in the community. The prevalence of S. aureus nasal carriage was 30.5%. Only one subject, with predisposing risk factors for acquisition, was identified as carrier of MRSA (prevalence of 0.12%). The presence of MRSA in the community of our area still appears to be a rare event. Among methicillin-susceptible S. aureus (MSSA) isolates, a surprisingly high rate (18%) of resistance to rifampin was observed. PMID:12403117

  13. Antimicrobial Susceptibility Profiles of Staphylococcus aureus Isolates Recovered from Humans, Environmental Surfaces, and Companion Animals in Households of Children with Community-Onset Methicillin-Resistant S. aureus Infections.

    PubMed

    Morelli, John J; Hogan, Patrick G; Sullivan, Melanie L; Muenks, Carol E; Wang, Jeffrey W; Thompson, Ryley M; Burnham, Carey-Ann D; Fritz, Stephanie A

    2015-10-01

    Our objective was to determine the antibiotic susceptibility profiles of Staphylococcus aureus isolates recovered from 110 households of children with community-onset methicillin-resistant S. aureus (MRSA) infections. Cultures were obtained from household members, household objects, and dogs and cats, yielding 1,633 S. aureus isolates. The S. aureus isolates were heterogeneous, although more than half were methicillin resistant. The highest proportion of MRSA was found in bathrooms. The majority of isolates were susceptible to antibiotics prescribed in outpatient settings.

  14. Antibiotic susceptibility survey of blood-borne MRSA isolates in Japan from 2008 through 2011.

    PubMed

    Hanaki, Hideaki; Cui, Longzhu; Ikeda-Dantsuji, Yurika; Nakae, Taiji; Honda, Junichi; Yanagihara, Katsunori; Takesue, Yoshio; Matsumoto, Tetsuya; Sunakawa, Keisuke; Kaku, Mitsuo; Tomono, Kazunori; Fukuchi, Kunihiko; Kusachi, Shinya; Mikamo, Hiroshige; Takata, Tohru; Otsuka, Yoshihito; Nagura, Osanori; Fujitani, Shigeki; Aoki, Yosuke; Yamaguchi, Yoshio; Tateda, Kazuhiro; Kadota, Junichi; Kohno, Shigeru; Niki, Yoshihito

    2014-09-01

    We conducted an antibiotic susceptibility survey of 830 blood-borne methicillin resistant Staphylococcus aureus collected from nationwide hospitals in Japan over a three-year period from January 2008 through May 2011. Antibiotic susceptibility was judged according to the criteria recommended by the Clinical Laboratory Standard Institute. Over 99% of the MRSA showed to be susceptible to teicoplanin, linezolid, sulfamethoxazole/trimethoprim and vancomycin, and over 97% of them were susceptible to daptomycin, arbekacin and rifampin. The majority of the MRSA strains showed resistant to minocycline, meropenem, imipenem, clindamycin, ciprofloxacin, cefoxitin, and oxacillin in the rates of 56.6, 72.9, 73.7, 78.7, 89.0, 99.5, and 99.9%, respectively. Among the MRSA strains, 72 showed reduced susceptibility to vancomycin, including 8 strains (0.96%) of vancomycin-intermediate S. aureus (VISA), 54 (6.51%) of heterogeneous vancomycin-intermediate S. aureus (hVISA), and 55 (5.63%) of β-lactam antibiotics-induced vancomycin resistant S. aureus (BIVR). Unexpectedly, among the 54 hVISA and 55 BIVR, 45 isolates (83.3% and 81.8%, respectively) showed both hVISA and BIVR phenotypes. A new trend of vancomycin resistance found in this study was that VISA strains were still prevalent among the bacteremic specimens. The high rates of the hVISA/BIVR two-phenotypic vancomycin resistance, and the prevalence of VISA in the bloodborne MRSA call attention in the MRSA epidemiology in Japan.

  15. Community-acquired methicillin-resistant Staphylococcus aureus infections in two scuba divers returning from the Philippines.

    PubMed

    Bochet, Mélanie; Francois, Patrice; Longtin, Yves; Gaide, Olivier; Renzi, Gesuele; Harbarth, Stephan

    2008-01-01

    We describe two patients who had skin infection due to identical strains of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) after returning from the Philippines. Both patients did not share risk factors for CA-MRSA acquisition besides scuba diving. Scuba diving equipment may represent a possible new mode of acquisition of CA-MRSA.

  16. Methicillin-resistant Staphylococcus aureus, Western Australia

    PubMed Central

    Dailey, Lynne; Coombs, Geoffrey W.; O'Brien, Frances G.; Pearman, John W.; Christiansen, Keryn; Grubb, Warren B.

    2005-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) continues to be a notable cause of hospital-acquired infections. A statewide screening and control policy was implemented in Western Australia (WA) after an outbreak of epidemic MRSA in a Perth hospital in 1982. We report on statutory notifications from1998 to 2002 and review the 20-year period from 1983 to 2002. The rate of reporting of community-associated Western Australia MRSA (WAMRSA) escalated from 1998 to 2002 but may have peaked in 2001. Several outbreaks were halted, but they resulted in an increase in reports as a result of screening. A notable increase in ciprofloxacin resistance during the study period was observed as a result of more United Kingdom epidemic MRSA (EMRSA) -15 and -16. WA has seen a persistently low incidence of multidrug-resistant MRSA because of the screening and decolonization program. Non–multidrug-resistant, community-associated WAMRSA strains have not established in WA hospitals. PMID:16318700

  17. Usefulness of previous methicillin-resistant Staphylococcus aureus screening results in guiding empirical therapy for S aureus bacteremia

    PubMed Central

    Bai, Anthony D; Burry, Lisa; Showler, Adrienne; Steinberg, Marilyn; Ricciuto, Daniel; Fernandes, Tania; Chiu, Anna; Raybardhan, Sumit; Tomlinson, George A; Bell, Chaim M; Morris, Andrew M

    2015-01-01

    BACKGROUND: Staphylococcus aureus bacteremia (SAB) is an important infection. Methicillin-resistant S aureus (MRSA) screening is performed on hospitalized patients for infection control purposes. OBJECTIVE: To assess the usefulness of past MRSA screening for guiding empirical antibiotic therapy for SAB. METHODS: A retrospective cohort study examined consecutive patients with confirmed SAB and previous MRSA screening swab from six academic and community hospitals between 2007 and 2010. Diagnostic test properties were calculated for MRSA screening swab for predicting methicillin resistance of SAB. RESULTS: A total of 799 patients underwent MRSA screening swabs before SAB. Of the 799 patients, 95 (12%) had a positive and 704 (88%) had a negative previous MRSA screening swab. There were 150 (19%) patients with MRSA bacteremia. Overall, previous MRSA screening swabs had a positive likelihood ratio of 33 (95% CI 18 to 60) and a negative likelihood ratio of 0.45 (95% CI 0.37 to 0.54). Diagnostic accuracy differed depending on mode of acquisition (ie, community-acquired, nosocomial or health care-associated infection) (P<0.0001) and hospital (P=0.0002). At best, for health care-associated infection, prior MRSA screening swab had a positive likelihood ratio of 16 (95% CI 9 to 28) and a negative likelihood ratio of 0.27 (95% CI 0.17 to 0.41). CONCLUSIONS: A negative prior MRSA screening swab cannot reliably rule out MRSA bacteremia and should not be used to guide empirical antibiotic therapy for SAB. A positive prior MRSA screening swab greatly increases likelihood of MRSA, necessitating MRSA coverage in empirical antibiotic therapy for SAB. PMID:26361488

  18. High-Density Livestock Production and Molecularly Characterized MRSA Infections in Pennsylvania

    PubMed Central

    Casey, Joan A.; Shopsin, Bo; Cosgrove, Sara E.; Nachman, Keeve E.; Curriero, Frank C.; Rose, Hannah R.

    2014-01-01

    Background: European studies suggest that living near high-density livestock production increases the risk of sequence type (ST) 398 methicillin-resistant Staphylococcus aureus (MRSA) colonization. To our knowledge, no studies have evaluated associations between livestock production and human infection by other strain types. Objectives: We evaluated associations between MRSA molecular subgroups and high-density livestock production. Methods: We conducted a yearlong 2012 prospective study on a stratified random sample of patients with culture-confirmed MRSA infection; we oversampled patients from the Geisinger Health System with exposure to high-density livestock production in Pennsylvania. Isolates were characterized using S. aureus protein A (spa) typing and detection of Panton-Valentine leukocidin (PVL) and scn genes. We compared patients with one of two specific MRSA strains with patients with all other strains of MRSA isolates, using logistic regression that accounted for the sampling design, for two different exposure models: one based on the location of the animals (livestock model) and the other on crop field application of manure (crop field model). Results: Of 196 MRSA isolates, we identified 30 spa types, 47 PVL-negative and 15 scn-negative isolates, and no ST398 MRSA. Compared with quartiles 1–3 combined, the highest quartiles of swine livestock and dairy/veal crop field exposures were positively associated with community-onset-PVL-negative MRSA (CO-PVL-negative MRSA vs. all other MRSA), with adjusted odds ratios of 4.24 (95% CI: 1.60, 11.25) and 4.88 (95% CI: 1.40, 17.00), respectively. The association with CO-PVL-negative MRSA infection increased across quartiles of dairy/veal livestock exposure (trend p = 0.05). Conclusions: Our findings suggest that other MRSA strains, beyond ST398, may be involved in livestock-associated MRSA infection in the United States. Citation: Casey JA, Shopsin B, Cosgrove SE, Nachman KE, Curriero FC, Rose HR, Schwartz BS

  19. Spread of community-acquired meticillin-resistant Staphylococcus aureus skin and soft-tissue infection within a family: implications for antibiotic therapy and prevention.

    PubMed

    Amir, N H; Rossney, A S; Veale, J; O'Connor, M; Fitzpatrick, F; Humphreys, H

    2010-04-01

    Outbreaks or clusters of community-acquired meticillin-resistant Staphylococcus aureus (CA-MRSA) within families have been reported. We describe a family cluster of CA-MRSA skin and soft-tissue infection where CA-MRSA was suspected because of recurrent infections which failed to respond to flucloxacillin. While the prevalence of CA-MRSA is low worldwide, CA-MRSA should be considered in certain circumstances depending on clinical presentation and risk assessment. Surveillance cultures of family contacts of patients with MRSA should be considered to help establish the prevalence of CA-MRSA and to inform the optimal choice of empiric antibiotic treatment.

  20. Long-term persistence of MRSA in re-admitted patients

    PubMed Central

    Biertz, F.; Ziesing, S.; Gastmeier, P.; Chaberny, I. F.

    2010-01-01

    Background A better knowledge of methicillin-resistant Staphylococcus aureus (MRSA) persistence in hospitalised patients may impact on specific prevention strategies. We have investigated the persistence of MRSA-carriage in patients admitted and re-admitted to a university hospital. Patients and methods Between January 2002 and October 2005 all MRSA-positive patients admitted to the university hospital of Hannover Medical School were assessed at first admission and all subsequent re-admissions. Patients re-admitted at least once were analysed for the persistence or loss of MRSA. The association of possible factors influencing the persistence of MRSA colonisation or infection (age group, gender, decolonisation therapy during first hospital stay due to MRSA positivity and colonisation of different anatomical sites) was analysed using univariate, multivariate and time-dependent analyses. Results A total of 1,032 patients who had tested positive at least once for MRSA were admitted to our hospital during the study period, accounting for 2,038 admissions. Of these patients, 403 (39.1%) were admitted more than once (from two times to 21 times), and 238 (59.1%) of the re-admitted patients remained MRSA positive during all subsequent admissions. Fifty-five (13.6%) patients tested MRSA negative at their last admission, and 61 (15.1%) tested MRSA negative at at least two consecutive admissions. In 27 (6.7%) patients, the MRSA status differed more than once between subsequent admissions. Overall, the half-life time (HLT) of MRSA persistence was 549 days, with the duration of persistence dependent on the colonisation of different anatomical sites (HLT only wounds 117 days; HLT mouth, throat, bronchial secretions 627 days; HLT nose, wounds and other body sites 801 days; p < 0.01) and was prolonged if more than one body site was MRSA-positive (HR 2.18, 95% confidence interval 1.52–3.15). Conclusion A detailed knowledge of the dynamics of the loss of MRSA infection could

  1. New epidemiology of Staphylococcus aureus infection in Asia.

    PubMed

    Chen, C-J; Huang, Y-C

    2014-07-01

    Not only is Asia the most populous region in the world, but inappropriate therapy, including self-medication with over-the-counter antimicrobial agents, is a common response to infectious diseases. The high antibiotic selective pressure among the overcrowded inhabitants creates an environment that is suitable for the rapid development and efficient spread of numerous multidrug-resistant pathogens. Indeed, Asia is among the regions with the highest prevalence rates of healthcare-associated methicillin-resistant Staphylococcus aureus (HA-MRSA) and community-associated methicillin-resistant S. aureus (CA-MRSA) in the world. Most hospitals in Asia are endemic for multidrug-resistant methicillin-resistant S. aureus (MRSA), with an estimated proportion from 28% (in Hong Kong and Indonesia) to >70% (in Korea) among all clinical S. aureus isolates in the early 2010s. Isolates with reduced susceptibility or a high level of resistance to glycopeptides have also been increasingly identified in the past few years. In contrast, the proportion of MRSA among community-associated S. aureus infections in Asian countries varies markedly, from <5% to >35%. Two pandemic HA-MRSA clones, namely multilocus sequence type (ST) 239 and ST5, are disseminated internationally in Asia, whereas the molecular epidemiology of CA-MRSA in Asia is characterized by clonal heterogeneity, similar to that in Europe. In this review, the epidemiology of S. aureus in both healthcare facilities and communities in Asia is addressed, with an emphasis on the prevalence, clonal structure and antibiotic resistant profiles of the MRSA strains. The novel MRSA strains from livestock animals have been considered to constitute a public health threat in western countries. The emerging livestock-associated MRSA strains in Asia are also included in this review.

  2. The Prevalence of MRSA Nasal Carriage in Preoperative Pediatric Orthopaedic Patients.

    PubMed

    Walrath, J J; Hennrikus, W L; Zalonis, C; Dyer, A M; Latorre, J E

    2016-01-01

    Nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) has been described as a risk factor for postsurgical infection. The purpose of this study is to determine the prevalence of MRSA in pediatric orthopaedic patients and whether being a MRSA carrier is a predictor of postoperative infection. Six hundred and ninety-nine consecutive pediatric patients who underwent MRSA nasal screening prior to surgery were studied. Postoperative cultures, total surgical site infections (SSIs), and epidemiological and surgical prophylaxis data were reviewed. Forty-four of 699 patients (6.29%) screened positive for MRSA. Nine of the 44 patients (20.5%) that screened positive for MRSA had a subsequent SSI compared to 10 of the 655 patients (1.52%) that screened negative (p < 0.05). All 9 patients with a SSI had myelomeningocele. The prevalence of MRSA was 6.30% and was predictive of postoperative infection. Children with myelomeningocele were at the highest risk for having a positive MRSA screening and developing SSI. PMID:27688914

  3. The Prevalence of MRSA Nasal Carriage in Preoperative Pediatric Orthopaedic Patients

    PubMed Central

    Walrath, J. J.; Zalonis, C.; Dyer, A. M.; Latorre, J. E.

    2016-01-01

    Nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) has been described as a risk factor for postsurgical infection. The purpose of this study is to determine the prevalence of MRSA in pediatric orthopaedic patients and whether being a MRSA carrier is a predictor of postoperative infection. Six hundred and ninety-nine consecutive pediatric patients who underwent MRSA nasal screening prior to surgery were studied. Postoperative cultures, total surgical site infections (SSIs), and epidemiological and surgical prophylaxis data were reviewed. Forty-four of 699 patients (6.29%) screened positive for MRSA. Nine of the 44 patients (20.5%) that screened positive for MRSA had a subsequent SSI compared to 10 of the 655 patients (1.52%) that screened negative (p < 0.05). All 9 patients with a SSI had myelomeningocele. The prevalence of MRSA was 6.30% and was predictive of postoperative infection. Children with myelomeningocele were at the highest risk for having a positive MRSA screening and developing SSI.

  4. The Prevalence of MRSA Nasal Carriage in Preoperative Pediatric Orthopaedic Patients

    PubMed Central

    Walrath, J. J.; Zalonis, C.; Dyer, A. M.; Latorre, J. E.

    2016-01-01

    Nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) has been described as a risk factor for postsurgical infection. The purpose of this study is to determine the prevalence of MRSA in pediatric orthopaedic patients and whether being a MRSA carrier is a predictor of postoperative infection. Six hundred and ninety-nine consecutive pediatric patients who underwent MRSA nasal screening prior to surgery were studied. Postoperative cultures, total surgical site infections (SSIs), and epidemiological and surgical prophylaxis data were reviewed. Forty-four of 699 patients (6.29%) screened positive for MRSA. Nine of the 44 patients (20.5%) that screened positive for MRSA had a subsequent SSI compared to 10 of the 655 patients (1.52%) that screened negative (p < 0.05). All 9 patients with a SSI had myelomeningocele. The prevalence of MRSA was 6.30% and was predictive of postoperative infection. Children with myelomeningocele were at the highest risk for having a positive MRSA screening and developing SSI. PMID:27688914

  5. Genetic Characterization of Staphylococcus aureus Isolated from Retail Meat in Riyadh, Saudi Arabia.

    PubMed

    Raji, Muhabat A; Garaween, Ghada; Ehricht, Ralf; Monecke, Stefan; Shibl, Atef M; Senok, Abiola

    2016-01-01

    Limited data exist from the Gulf Cooperation Council states on the prevalence and population dynamics of Staphylococcus aureus colonizing livestock or contaminating retail meat. This study was designed to determine the presence and genetic characteristics of Staphylococcus aureus isolated from raw retail meat sold in Riyadh, Saudi Arabia. Over a period of 9 months, different raw retail meat types were aseptically processed using the double broth enrichment technique, characteristic colonies from chromogenic and mannitol salt agar were further identified using conventional methods. Susceptibility to 9 antibiotics was determined using the disc diffusion technique. Interpretation of inhibition zone was done according to Clinical and Laboratory Standards Institute guidelines. Molecular characterization was carried out using the StaphyType DNA microarray technology. Twenty-five meat samples yielded Staphylococcus aureus isolates. Camel meat had the highest contamination rate with Methicillin resistant Staphylococcus aureus (MRSA) (20%) and Methicillin susceptible Staphylococcus aureus (28%), while poultry meat had the least contamination rate with MRSA (4%). The MRSA isolates were grouped into 4 clonal complexes (CCs) namely CC1-MRSA-IV/SCCfus (n = 2), CC15-MRSA-V/SCCfus (n = 4), CC80-MRSA-IV/PVL+ (n = 5), and CC88-MRSA-IV/PVL+ (n = 2). All CC15-MRSA-V/SCCfus isolates were obtained from camel meat. This is the first study to demonstrate the novel CC15-MRSA-V/SCCfus in retail camel meat. We recommend that surveillance studies should be incorporated in public health and food hygiene programs. PMID:27375611

  6. Genetic Characterization of Staphylococcus aureus Isolated from Retail Meat in Riyadh, Saudi Arabia

    PubMed Central

    Raji, Muhabat A.; Garaween, Ghada; Ehricht, Ralf; Monecke, Stefan; Shibl, Atef M.; Senok, Abiola

    2016-01-01

    Limited data exist from the Gulf Cooperation Council states on the prevalence and population dynamics of Staphylococcus aureus colonizing livestock or contaminating retail meat. This study was designed to determine the presence and genetic characteristics of Staphylococcus aureus isolated from raw retail meat sold in Riyadh, Saudi Arabia. Over a period of 9 months, different raw retail meat types were aseptically processed using the double broth enrichment technique, characteristic colonies from chromogenic and mannitol salt agar were further identified using conventional methods. Susceptibility to 9 antibiotics was determined using the disc diffusion technique. Interpretation of inhibition zone was done according to Clinical and Laboratory Standards Institute guidelines. Molecular characterization was carried out using the StaphyType DNA microarray technology. Twenty-five meat samples yielded Staphylococcus aureus isolates. Camel meat had the highest contamination rate with Methicillin resistant Staphylococcus aureus (MRSA) (20%) and Methicillin susceptible Staphylococcus aureus (28%), while poultry meat had the least contamination rate with MRSA (4%). The MRSA isolates were grouped into 4 clonal complexes (CCs) namely CC1-MRSA-IV/SCCfus (n = 2), CC15-MRSA-V/SCCfus (n = 4), CC80-MRSA-IV/PVL+ (n = 5), and CC88-MRSA-IV/PVL+ (n = 2). All CC15-MRSA-V/SCCfus isolates were obtained from camel meat. This is the first study to demonstrate the novel CC15-MRSA-V/SCCfus in retail camel meat. We recommend that surveillance studies should be incorporated in public health and food hygiene programs. PMID:27375611

  7. Community-onset Staphylococcus aureus Surveillance Programme annual report, 2012.

    PubMed

    Coombs, Geoffrey W; Daly, Denise A; Pearson, Julie C; Nimmo, Graeme R; Collignon, Peter J; McLaws, Mary-Louise; Robinson, James O; Turnidge, John D

    2014-03-01

    In 2012, the Australian Group on Antimicrobial Resistance (AGAR) conducted a community-onset period-prevalence survey of clinical Staphylococcus aureus isolated from hospital outpatients and general practice patients including nursing homes, long term care facilities and hospice patients. Day surgery and dialysis patients were excluded. Twenty-nine medical microbiology laboratories from all state and mainland territories participated. Isolates were tested by Vitek2® (AST-P612 card). Results were compared with previous AGAR community surveys. Nationally, the proportion of S. aureus that were methicillin-resistant S. aureus (MRSA) increased significantly from 11.5% in 2000 to 17.9% in 2012 (P<0.0001). Resistance to the non-ß-lactam antimicrobials varied between regions. No resistance was detected to vancomycin, teicoplanin or linezolid. Resistance in methicillin susceptible S. aureus was rare apart from erythromycin (12.8%) and was absent for vancomycin, teicoplanin, linezolid and daptomycin. The proportion of S. aureus characterised as health care-associated MRSA (HA-MRSA) was 5.1%. Three HA-MRSA clones were characterised, with 72.9% and 26.4% of HA-MRSA classified as ST22-IV [2B] (EMRSA-15) and ST239-III [3A] (Aus-2/3 EMRSA) respectively. Multi-clonal community-associated MRSA (CA-MRSA) accounted for 12.5% of all S. aureus. Regional variation in resistance in MRSA was primarily due to the differential distribution of the 2 major HA-MRSA clones; ST239-III [3A] (Aus-2/3 EMRSA), which is resistant to multiple non-ß-lactam antimicrobials, and ST22-IV [2B] (EMRSA-15), which is resistant to ciprofloxacin and typically erythromycin. Although the majority of CA-MRSA were non-multi-resistant, a significant expansion of Panton-Valentine leukocidin (PVL) positive CA-MRSA clones has occurred nationally. The mean age of patients (31.7 years, 95% CI 28.9-34.5) with a PVL positive CA-MRSA infection was significantly lower (P<0.0001), than the mean age of patients with a PVL

  8. Coagulase-negative staphylococci as reservoirs of genes facilitating MRSA infection: Staphylococcal commensal species such as Staphylococcus epidermidis are being recognized as important sources of genes promoting MRSA colonization and virulence.

    PubMed

    Otto, Michael

    2013-01-01

    Recent research has suggested that Staphylococcus epidermidis is a reservoir of genes that, after horizontal transfer, facilitate the potential of Staphylococcus aureus to colonize, survive during infection, or resist antibiotic treatment, traits that are notably manifest in methicillin-resistant S. aureus (MRSA). S. aureus is a dangerous human pathogen and notorious for acquiring antibiotic resistance. MRSA in particular is one of the most frequent causes of morbidity and death in hospitalized patients. S. aureus is an extremely versatile pathogen with a multitude of mechanisms to cause disease and circumvent immune defenses. In contrast, most other staphylococci, such as S. epidermidis, are commonly benign commensals and only occasionally cause disease. Recent findings highlight the key importance of efforts to better understand how genes of staphylococci other than S. aureus contribute to survival in the human host, how they are transferred to S. aureus, and why this exchange appears to be uni-directional.

  9. Absence of human innate immune evasion complex in LA-MRSA ST5 strains isolated from pigs, swine facilities, and humans with swine contact

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Since its first ties to swine, livestock associated methicillin-resistant Staphylococcus aureus (LA-MRSA) has raised public health concerns because livestock may be the largest reservoir of MRSA outside the hospital setting. In contrast to Europe and Asia, where the primary sequence type...

  10. La(III) complex involving the O,N-donor environment of quinazoline-4(3H)-one Schiff’s base and their antimicrobial attributes against methicillin-resistant Staphylococcus aureus (MRSA)

    NASA Astrophysics Data System (ADS)

    Siddappa, K.; Mane, Sunilkumar B.; Manikprabhu, Deene

    2014-09-01

    The incidence of methicillin-resistant Staphylococcus aureus increased during the past few decades, so there is an urgent need of new antimicrobial agents if public health is concerned. Though the Schiff’s bases and La(III) complex have enormous biological activity, but less attention was given in their synthesis. In the present investigation, we synthesized a new (E)-3-((2-hydroxynaphthalen-1-yl) methyleneamino)-2-methylquinazoline-4(3H)-one HNMAMQ Schiff’s base by the condensation of 3-(2-aminophenyl) quinazolin-2-methyl-4(3H)-one and 2-hydroxy-1-naphthaldehyde. The Schiff’s base HNMAMQ and its La(III) complex were characterized by elemental analyses, IR, NMR, mass spectra, and thermal studies. The newly synthesized Schiff’s base HNMAMQ and its La(III) complex were evaluated for their antimicrobial activity against methicillin-resistant Staphylococcus aureus isolated from the Gulbarga region in India. The Schiff’s base HNMAMQ and its La(III) complex showed good antimicrobial activity and thus represents a potential new drug of choice.

  11. Immunomodulatory effects of recombinant lactoferrin during MRSA infection.

    PubMed

    Hwang, Shen-An; Kruzel, Marian L; Actor, Jeffrey K

    2014-05-01

    Methicillin-resistant Staphylococcus aureus (MRSA) infection remains a serious hazard to global health. The use of immune modulatory therapy to combat infection is gaining an interest as a novel treatment alternative. Lactoferrin (LF), an iron binding protein with immune modulating properties, has the potential to modify the course of systemic MRSA infection. Specifically, LF is capable of limiting deleterious inflammatory responses while promoting the development of antigen specific T-cell activity. The efficacy of a novel recombinant mouse LF (rmLF) to protect against MRSA infection was examined in a mouse peritonitis model. BALB/c mice were infected with a lethal dose of MRSA and treated at 2h post-infection with rmLF. Effects of rmLF on MRSA-infected primary monocytes and granulocytes were analyzed for inflammatory mediators. The rmLF treated mice demonstrated a modest increase in survival of more than 24h, albeit with reduced bacteremia. Serum cytokines, IL-17 and IL-6, were significantly reduced post-challenge post-rmLF treatment. The rmLF led to a minor decrease in IL-1b, and a slight increase in TNF-a production. Preliminary investigation towards human clinical relevance was accomplished using human blood derived monocytes and granulocytes infected with MRSA and treated with homologous recombinant human LF (rhLF). Treatment with (rhLF) led to increased production of IFN-g and IL-2. The human cell studies also showed a concurrent decrease in TNF-a, IL-6, IL-1b, IL-12p40, and IL-10. These results indicate that the rmLF and rhLF have a high degree of overlap to modify inflammatory responses, although differences in activities were observed between the two heterologous recombinant molecules.

  12. Methicillin-Resistant Staphylococcus aureus Ocular Infection in Taiwan: Clinical Features, Genotying, and Antibiotic Susceptibility.

    PubMed

    Kang, Yu-Chuan; Hsiao, Ching-Hsi; Yeh, Lung-Kun; Ma, David H K; Chen, Phil Y F; Lin, Hsin-Chiung; Tan, Hsin-Yuan; Chen, Hung-Chi; Chen, Shin-Yi; Huang, Yhu-Chering

    2015-10-01

    Methicillin-resistant Staphylococcus aureus (MRSA) infection is an important public health issue. This observational study aimed to characterize clinical features, antibiotic susceptibility, and genotypes of ocular infections caused by MRSA based on the clinical and molecular definitions of community-associated (CA) and healthcare-associated (HA) strains.Fifty-nine patients with culture-proven S aureus ocular infection were enrolled from January 1, 2010 to December 31, 2011 at Chang Gung Memorial Hospital, Taiwan. Antibiotic susceptibility was verified using disk diffusion/E test. For characterization, staphylococcal cassette chromosome mec (SCCmec), pulsed-field gel electrophoresis (PFGE), multilocus sequence type (MLST), and Panton-Valentine leukocidin (PVL) gene, were performed. MRSA isolates from the patients with HA factors were classified as clinically defined HA-MRSA, and those carrying SCCmec type I to III as molecularly defined HA-MRSA.Thirty-four patients with MRSA ocular infection were identified. The most common clone of CA-MRSA and HA-MRSA isolates was ST59/PFGE type D/SCCmec IV,VT/PVL (+) (n = 12) and CC 239/PFGE type A/SCCmec III, IIIA/PVL(-) (n = 10), respectively. All the 11 patients with molecularly defined HA-MRSA infections and 50% of the 22 patients with molecularly defined CA-MRSA infections were found to have HA factors (P = .005). CA-MRSA tended to cause lid infections, whereas HA-MRSA tended to cause corneal infections. Contrary to HA-MRSA isolates, nearly all the CA-MRSA isolates were susceptible to trimethoprim/sulfamethoxazole and fluoroquinolones under either clinical or molecular classifications.In Taiwan, CA-MRSA isolates exhibited considerably higher susceptibility to fluoroquinolones when compared with HA-MRSA isolates. A strong correlation was observed between the HA factors and molecularly defined HA-MRSA isolates.

  13. Dissemination of antibiotic resistance in methicillin-resistant Staphylococcus aureus and vancomycin-resistant S aureus strains isolated from hospital effluents.

    PubMed

    Mandal, Santi M; Ghosh, Ananta K; Pati, Bikas R

    2015-12-01

    Vancomycin-resistant Staphylococcus aureus (VRSA) and methicillin-resistant S aureus (MRSA) strains were examined in hospital effluents. Most S aureus strains are resistant to methicillin (MRSA), followed by tetracycline. Approximately 15% of MRSA strains are also resistant to vancomycin (VRSA). All VRSA strains developed a VanR/VanS-regulated 2-component system of VanA-type resistance in their genome. Results indicate that there is a possibility of developing resistance to aminoglycosides by VRSA strains in the near future.

  14. Staphylococcus aureus 'Down Under': contemporary epidemiology of S. aureus in Australia, New Zealand, and the South West Pacific.

    PubMed

    Williamson, D A; Coombs, G W; Nimmo, G R

    2014-07-01

    The clinical and molecular epidemiology of Staphylococcus aureus disease has changed considerably over the past two decades, particularly with the emergence and spread of community-associated methicillin-resistant S. aureus (CA-MRSA) clones. Indeed, some of the first global descriptions of CA-MRSA were from remote indigenous communities in Western Australia, and from Pacific Peoples in New Zealand. The epidemiology of S. aureus infections in the South West Pacific has several unique features, largely because of the relative geographical isolation and unique indigenous communities residing in this region. In particular, a number of distinct CA-MRSA clones circulate in Australia and New Zealand, such as sequence type (ST) 93 methicillin-resistant S. aureus (MRSA) (Queensland clone) and clonal complex 75 S. aureus (Staphylococcus argenteus) in Australia, and ST30 MRSA (Southwest Pacific clone) in New Zealand. In addition, there is a disproportionate burden of S. aureus disease in indigenous paediatric populations, particularly in remote Aboriginal communities in Australia, and in Pacific Peoples and Maori in New Zealand. In this review, we provide a contemporary overview of the clinical and molecular epidemiology of S. aureus disease in the South West Pacific region, with a particular focus on features distinct to this region.

  15. Importance of methicillin-resistant Staphylococcus aureus eradication in carriers to prevent postoperative methicillin-resistant Staphylococcus aureus surgical site infection.

    PubMed

    Pofahl, Walter E; Ramsey, Keith M; Nobles, Delores L; Cochran, M Kathy; Goettler, Claudia

    2011-01-01

    Although infrequent, postoperative methicillin-resistant Staphylococcus aureus (MRSA) surgical site infection (SSI) is associated with significant morbidity and cost. Previous studies have identified the importance of MRSA screening to diminish the risk of postoperative MRSA SSI. The current study quantifies the importance of eradication of the MRSA carrier state to prevent MRSA SSI. Beginning February 2007, all admissions to an 800-bed tertiary care hospital were screened for MRSA by nasal swab using rapid polymerase chain reaction-based testing. Patients found to be nasal carriers of MRSA were treated with 2 per cent mupirocin nasal ointment and 4 per cent chlorhexidine soap before surgery. The subset of patients undergoing procedures that are part of the Surgical Care Improvement Project (SCIP) were followed for MRSA SSI (n = 8980). The results of preoperative MRSA screening and eradication of the carrier state were analyzed. Since the initiation of universal MRSA screening, 11 patients undergoing SCIP procedures have developed MRSA SSI (0.12%). Of these, six patients (55%) had negative preoperative screens. Of the five patients with positive preoperative screens, only one received treatment to eradicate the carrier state. In patients who develop MRSA SSI, failure to treat the carrier state before surgery results in MRSA SSI. PMID:21396301

  16. MRSA in Africa: Filling the Global Map of Antimicrobial Resistance

    PubMed Central

    Falagas, Matthew E.; Karageorgopoulos, Drosos E.; Leptidis, John; Korbila, Ioanna P.

    2013-01-01

    We sought to assess the prevalence of methicillin-resistance among Staphylococcus aureus isolates in Africa. We included articles published in 2005 or later reporting for the prevalence of MRSA among S. aureus clinical isolates. Thirty-two studies were included. In Tunisia, the prevalence of MRSA increased from 16% to 41% between 2002–2007, while in Libya it was 31% in 2007. In South Africa, the prevalence decreased from 36% in 2006 to 24% during 2007–2011. In Botswana, the prevalence varied from 23–44% between 2000–2007. In Algeria and Egypt, the prevalence was 45% and 52% between 2003–2005, respectively. In Nigeria, the prevalence was greater in the northern than the southern part. In Ethiopia and the Ivory Coast, the prevalence was 55% and 39%, respectively. The prevalence of MRSA was lower than 50% in most of the African countries, although it appears to have risen since 2000 in many African countries, except for South Africa. PMID:23922652

  17. Community-associated methicillin-resistant Staphylococcus aureus in college residential halls.

    PubMed

    Tonn, Katelynn; Ryan, Timothy J

    2013-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) was once a predominantly hospital-acquired organism but community-associated MRSA (CA-MRSA) has become a concern in athletics, prisons, and other nonclinical closed populations. As such, college residential hall occupants and workers may be at elevated risk of spreading or contracting MRSA. Environmental samples were obtained to identify the occurrence of MRSA on surfaces in bathrooms of 15 university residential halls. Sterile swabs and BBL CHROMagar plates were used to sample seven categories of potentially contaminated surfaces in each location. Frequencies and descriptive statistics were prepared. All sites had at least one positive sample for MRSA, and shower floors displayed the greatest prevalence (50%). These results indicate areas for heightened sanitation, and illustrate CA-MRSA potential from such surfaces. The need for hygiene education of affected persons about skin and soft tissue infections like MRSA, and intervention opportunities for public health professionals, are discussed.

  18. Prevalence of community-associated methicillin-resistant Staphylococcus aureus in high school wrestling environments.

    PubMed

    Stanforth, Bethany; Krause, Andrew; Starkey, Chad; Ryan, Timothy J

    2010-01-01

    Methicillin-resistant Staphylococcus Aureus (MRSA) was predominantly a hospital-acquired organism; recently, however, community-associated MRSA (CA-MRSA) has been causing outbreaks in otherwise healthy individuals involved in athletics. As such, CA-MRSA is of emerging concern to sanitarians and public health officials. Secondary school athletic trainers and student athletes may be at elevated risk of spreading or contracting MRSA. The absence of proper hygiene protocols or equipment may further increase this risk. In the study discussed in this article, environmental samples were obtained to identify the prevalence of MRSA on surfaces in high school athletic training and wrestling facilities mats in nine rural Ohio high schools. Frequencies and descriptive statistics were prepared. All nine (100%) of the sites tested had at least one positive sample for the presence of MRSA. The need for heightened sanitation, hygiene education of affected persons about skin and soft tissue infections like MRSA, and intervention opportunities for public health professionals are discussed.

  19. Antibacterial synergy between rosmarinic acid and antibiotics against methicillin-resistant Staphylococcus aureus

    PubMed Central

    Ekambaram, Sanmuga Priya; Perumal, Senthamil Selvan; Balakrishnan, Ajay; Marappan, Nathiya; Gajendran, Sabari Srinivasan; Viswanathan, Vinodhini

    2016-01-01

    Aim/Background: Medicinal plants have ability to resist microorganisms by synthesizing secondary metabolites such as phenols. Rosmarinic acid (RA) is a phenylpropanoid widely distributed in plants and well known as therapeutic and cosmetic agent. Methicillin-resistant Staphylococcus aureus (MRSA) which is resistant to all kinds of β-lactams, threatens even most potent antibiotics. To improve the efficiency of antibiotics against multi-drug resistant bacteria and to reduce the antibiotic dose, the antibacterial activity and the synergistic effect of RA with standard antibiotics against S. aureus and MRSA was investigated. Materials and Methods: Antibacterial activity of RA against S. aureus and a clinical isolate of MRSA was evaluated by agar well diffusion method. Minimum inhibitory concentration (MIC) of RA was determined by broth dilution method. Synergism of RA with various antibiotics against S. aureus and MRSA was studied by broth checkerboard method and time-kill kinetic assay. Effect of RA on microbial surface components recognizing adhesive matrix molecules (MSCRAMM’s) of S. aureus and MRSA was studied using sodium dodecyl sulfate - polyacrylamide gel electrophoresis. Results: MIC of RA was found to be 0.8 and 10 mg/ml against S. aureus and MRSA, respectively. RA was synergistic with vancomycin, ofloxacin, and amoxicillin against S. aureus and only with vancomycin against MRSA. The time-kill analysis revealed that synergistic combinations were a more effective than individual antibiotics. MSCRAMM’s protein expression of S. aureus and MRSA was markedly suppressed by RA + vancomycin combination rather than RA alone. Conclusion: The synergistic effects of RA with antibiotics were observed against S. aureus and MRSA. RA showed inhibitory effect on the surface proteins MSCRAMM’s. Even though RA was shown to exhibit a synergistic effect with antibiotics, the MIC was found to be higher. Thus, further studies on increasing the efficacy of RA can develop it

  20. Survey of methicillin-resistant Staphylococcus aureus strains from two hospitals in El Paso, Texas.

    PubMed

    O'Brien, Frances G; Lim, Tien Tze; Winnett, David C; Coombs, Geoffrey W; Pearson, Julie C; Delgado, Alejandro; Langevin, Mark J; Cantore, Stephanie A; Gonzalez, Leti; Gustafson, John E

    2005-06-01

    Seventy-one percent of 76 methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from two medical centers in El Paso, Texas, represent three similar pulsed-field gel electrophoresis types. Overall, six pulsed-field types were identified represented by multilocus sequence/staphylococcal chromosomal cassette DNA mec (SCCmec) types: ST5-MRSA-II; ST36-MRSA-II; ST8 (untypeable SCCmec); and a newly described clonal cluster 8 strain, ST507-MRSA-IV. This study demonstrates the presence of multiple-antibiotic-resistant epidemic MRSA clones in El Paso.

  1. Persistence of nasal colonization with livestock-associated methicillin-resistant Staphylococcus aureus in pig farmers after holidays from pig exposure.

    PubMed

    Köck, Robin; Loth, Bea; Köksal, Mahir; Schulte-Wülwer, Josef; Harlizius, Jürgen; Friedrich, Alexander W

    2012-06-01

    Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) is frequently transmitted from pigs to farmers. This study analyzed whether an absence from direct contact with pigs during holidays had an impact on nasal MRSA colonization rates of pig farmers. Overall, 59% of the farmers did not clear MRSA colonization during their leave.

  2. "Not Rocket Science" or "No Silver Bullet"? Media and Government Discourses about MRSA and Cleanliness

    ERIC Educational Resources Information Center

    Koteyko, Nelya; Nerlich, Brigitte; Crawford, Paul; Wright, Nick

    2008-01-01

    Methicillin-resistant "Staphylococcus aureus" (MRSA), commonly called a superbug, has recently been a major political issue in the UK, playing a significant role in debates over health policy in the general election held in 2005. While science recognizes the lack of evidence with regards to the effectiveness of existing measures implemented to…

  3. The efficacy of silver dressings and antibiotics on MRSA and MSSA isolated from burn patients.

    PubMed

    Percival, Steven L; Thomas, John G; Slone, Will; Linton, Sara; Corum, Linda; Okel, Tyler

    2011-11-01

    In this study our objectives were (1) to investigate whether meticillin-resistant Staphylococcus aureus (MRSA) showed an increased tolerance to silver wound dressings compared with meticillin-sensitive S. aureus (MSSA); and (2) to evaluate the effects of bacterial phenotypic states of MRSA and MSSA, and pH, on the activity of silver wound dressings and two antibiotics, ampicillin and clindamycin. Twenty MRSA strains and 10 MSSA strains isolated from burns patients in South Africa were evaluated for their susceptibility to a silver alginate and a silver carboxymethyl cellulose wound dressing, employing a corrected zone of inhibition assay, conducted on Mueller Hinton agar and a poloxamer-based biofilm model. When exposed to the two silver dressings, all 30 S. aureus strains showed susceptibility. Possible enhanced antimicrobial efficacy of the silver dressings occurred when pH was lowered to 5.5, compared with a pH of 7.0. When all S. aureus were grown in the biofilm phenotypic state and exposed to both silver dressings and antibiotics, enhanced tolerance was noted. Susceptibility to silver was overall higher for MRSA when compared with MSSA. This study showed that the effect of pH and bacterial phenotypic state must be considered when the antimicrobial activity of silver wound dressings is being investigated. It is evident from the data generated that both pH and the bacterial phenotypic state are factors that induce changes that affect both antimicrobial performance and bacterial susceptibility.

  4. Nosocomial Infections and Drug Susceptibility Patterns in Methicillin Sensitive and Methicillin Resistant Staphylococcus aureus

    PubMed Central

    Sharma, Nitish Kumar; Garg, Raina; Baliga, Shrikala; Bhat K., Gopalkrishna

    2013-01-01

    Aim: Staphylococcus aureus is one of the leading causes of nosocomial infections and is known for its ability to develop resistance to antibiotics. The drug susceptibility pattern of Methicillin Sensitive S. aureus (MSSA) and Methicillin Resistant S. aureus (MRSA) may vary. Aims and Objectives: This study was carried out to determine and compare the drug susceptibility patterns in nosocomial MSSA and MRSA. Material and Methods: The study was conducted between September 2009 and August 2011. Standard conventional methods were used for the isolation and identification of S. aureus. MRSA was identified by the cefoxitin (30 μg) disk method. Antibiotic susceptibility test was done using Kirby-Bauer disk diffusion method and the interpretation of the results was done using CLSI guidelines. Results: Out of 685 strains of S. aureus studied, 173(25.25%) were MRSA and 512 (74.25%) were MSSA. Out of 173 MRSA strains, 114(65.89%) were isolated from pus, 22(12.71%) from vaginal swab, 18(10.40%) from central catheter tip and the remaining from other specimens. All isolates were susceptible to vancomycin and least number of isolates were susceptible to penicillin. MRSA displayed significantly higher resistance to other antibiotics. 45.7% of MRSA strains were resistant to clindamycin, 64.7% to ciprofloxacin, 87.3% to cotrimoxazole, 54.3% to erythromycin, 17.3% to gentamicin, 16.8% to netilmycin, and 58.38% to tetracycline. Inducible clindamycin resistance was detected in 37 (21.38%) strains of MRSA. Conclusion: Nosocomial infections caused by MRSA is a significant problem. MRSA and MSSA differ with their susceptibility to antibiotics. All MRSA isolates in our hospitals were susceptible to vancomycin. Proper selection of the antibiotics based on antibiotic susceptibility test results is needed for effective treatment and prevention of emergence of resistance in MRSA and MSSA. PMID:24298469

  5. Antimicrobial Resistance and Molecular Characteristics of Nasal Staphylococcus aureus Isolates From Newly Admitted Inpatients.

    PubMed

    Chen, Xu; Sun, Kangde; Dong, Danfeng; Luo, Qingqiong; Peng, Yibing; Chen, Fuxiang

    2016-05-01

    Staphylococcus aureus, or methicillin-resistant S. aureus (MRSA), is a significant pathogen in both nosocomial and community infections. Community-associated MRSA (CA-MRSA) strains tend to be multi-drug resistant and to invade hospital settings. This study aimed to assess the antimicrobial resistance and molecular characteristicsof nasal S. aureus among newlyadmitted inpatients.In the present study, 66 S. aureus isolates, including 10 healthcare-associated MRSA (HA-MRSA), 8 CA-MRSA, and 48 methicillin-sensitive S. aureus (MSSA) strains, were found in the nasal cavities of 62 patients by screening 292 newlyadmitted patients. Antimicrobial resistance and molecular characteristics of these isolates, including spa-type, sequence type (ST) and SCCmec type, were investigated. All isolates were sensitive to linezolid, teicoplanin, and quinupristin/dalfopristin, but high levels of resistance to penicillin and erythromycin were detected. According to D-test and erm gene detection results, the cMLS(B) and iMLS(B) phenotypes were detected in 24 and 16 isolates, respectively. All 10 HA-MRSA strains displayed the cMLS(B) phenotypemediated by ermA or ermA/ermC, while the cMLS(B) CA-MRSA and MSSA strains carried the ermB gene. Molecular characterization revealedall 10 HA-MRSA strains were derived from the ST239-SCCmec III clone, and four out of eight CA-MRSA strains were t437-ST59-SCCmec V. The results suggest that patients play an indispensable role in transmitting epidemic CA-MRSA and HA-MRSA strains.

  6. Antimicrobial Resistance and Molecular Characteristics of Nasal Staphylococcus aureus Isolates From Newly Admitted Inpatients

    PubMed Central

    Chen, Xu; Sun, Kangde; Luo, Qingqiong; Peng, Yibing

    2016-01-01

    Staphylococcus aureus, or methicillin-resistant S. aureus (MRSA), is a significant pathogen in both nosocomial and community infections. Community-associated MRSA (CA-MRSA) strains tend to be multi-drug resistant and to invade hospital settings. This study aimed to assess the antimicrobial resistance and molecular characteristicsof nasal S. aureus among newlyadmitted inpatients.In the present study, 66 S. aureus isolates, including 10 healthcare-associated MRSA (HA-MRSA), 8 CA-MRSA, and 48 methicillin-sensitive S. aureus (MSSA) strains, were found in the nasal cavities of 62 patients by screening 292 newlyadmitted patients. Antimicrobial resistance and molecular characteristics of these isolates, including spa-type, sequence type (ST) and SCCmec type, were investigated. All isolates were sensitive to linezolid, teicoplanin, and quinupristin/dalfopristin, but high levels of resistance to penicillin and erythromycin were detected. According to D-test and erm gene detection results, the cMLSB and iMLSB phenotypes were detected in 24 and 16 isolates, respectively. All 10 HA-MRSA strains displayed the cMLSB phenotypemediated by ermA or ermA/ermC, while the cMLSB CA-MRSA and MSSA strains carried the ermB gene. Molecular characterization revealedall 10 HA-MRSA strains were derived from the ST239-SCCmec III clone, and four out of eight CA-MRSA strains were t437-ST59-SCCmec V. The results suggest that patients play an indispensable role in transmitting epidemic CA-MRSA and HA-MRSA strains. PMID:26915614

  7. Community-acquired methicillin-resistant Staphylococcus aureus in Central Australia.

    PubMed

    Stevens, Claire L; Ralph, Anna; McLeod, James E T; McDonald, Malcolm I

    2006-01-01

    To date, there has been scant information about the burden of methicillin-resistant Staphylococcus aureus infections in Central Australia. Our aims were to determine the proportion of Staphylococcus aureus infections due to methicillin-resistant strains in Central Australia, to characterise resistance to non-beta lactam antibiotics and to correlate findings with available demographic information. We retrospectively reviewed S. aureus isolates identified by the Microbiology Laboratory of the Pathology Department, Alice Springs Hospital between September 2005 and February 2006. Multi-resistance was defined as resistance to three or more non-beta lactam antibiotics. We identified the recovery site and extended antibiotic resistance profile of each isolate. Demographic data included place of residence, discharge diagnosis and ethnicity. There were 524 S. aureus isolates: 417 (79.6%) methicillin-sensitive S. aureus, 104 (19.7%) non-multi-resistant MRSA (nmrMRSA) and 3 (0.7%) multi-resistant MRSA (mrMRSA). MRSA accounted for 7/22 (32%) invasive infections and 91/474 (19.2%) cases of staphylococcal skin infections. Aboriginal people comprised 89 per cent (93/104) of patients with nmrMRSA; 57 per cent lived in remote communities, 21 per cent in suburban Alice Springs, and 18 per cent in Alice Springs Town Camps. Six per cent (6/104) of nmrMRSA were hospital-acquired. Of the nmrMRSA isolates, 57 per cent (59/104) were resistant to erythromycin and 7 per cent (7/104) to fusidic acid. All MRSA isolates were susceptible to co-trimoxazole. In conclusion, Central Australia has high rates of community-acquired nmrMRSA and low rates of multi-resistant MRSA. Erythromycin resistance in S. aureus is also common. These findings should prompt the review of antimicrobial prescribing guidelines for the region, especially for treatment of skin and soft tissue infections.

  8. Emodin is identified as the active component of ether extracts from Rhizoma Polygoni Cuspidati, for anti-MRSA activity.

    PubMed

    Cao, Feng; Peng, Wei; Li, Xiaoli; Liu, Ming; Li, Bin; Qin, Rongxin; Jiang, Weiwei; Cen, Yanyan; Pan, Xichun; Yan, Zifei; Xiao, Kangkang; Zhou, Hong

    2015-06-01

    This study investigated the anti-methicillin-resistant Staphylococcus aureus (anti-MRSA) activity and chemical compositions of ether extracts from Rhizoma Polygoni Cuspidati (ET-RPC). Significant anti-MRSA activities of ET-RPC against MRSA252 and MRSA clinical strains were tested in in vitro antibacterial experiments, such as inhibition zone diameter test, minimal inhibitory concentration test, and dynamic bacterial growth assay. Subsequently, 7 major compounds of ET-RPC were purified and identified as polydatin, resveratrol-4-O-d-(6'-galloyl)-glucopyranoside, resveratrol, torachryson-8-O-glucoside, emodin-8-O-glucoside, 6-hydroxy-emodin, and emodin using liquid chromatography - electrospray ionization - tandem mass spectrometry. After investigation of anti-MRSA activities of the 7 major compounds, only emodin had significant anti-MRSA activity. Further, transmission electron microscopy was used to observe morphological changes in the cell wall of MRSA252, and the result revealed that emodin could damage the integrity of cell wall, leading to loss of intracellular components. In summary, our results showed ET-RPC could significantly inhibit bacterial growth of MRSA strains. Emodin was identified as the major compound with anti-MRSA activity; this activity was related to destruction of the integrity of the cell wall and cell membrane. PMID:25966789

  9. Dose-response relationship between antimicrobial drugs and livestock-associated MRSA in pig farming.

    PubMed

    Dorado-García, Alejandro; Dohmen, Wietske; Bos, Marian E H; Verstappen, Koen M; Houben, Manon; Wagenaar, Jaap A; Heederik, Dick J J

    2015-06-01

    The farming community can be a vehicle for introduction of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in hospitals. During 2011-2013, an 18-month longitudinal study aimed at reducing the prevalence of LA-MRSA was conducted on 36 pig farms in the Netherlands. Evaluations every 6 months showed a slight decrease in MRSA prevalence in animals and a stable prevalence in farmers and family members. Antimicrobial use, expressed as defined daily dosages per animal per year, decreased 44% during the study period and was associated with declining MRSA prevalence in pigs. MRSA carriage in animals was substantially higher at farms using cephalosporins. Antimicrobial use remained strongly associated with LA-MRSA in humans regardless of the level of animal contact. A risk factor analysis outlined potential future interventions for LA-MRSA control. These results should encourage animal and public health authorities to maintain their efforts in reducing antimicrobial use in livestock and ask for future controlled intervention studies.

  10. MRSA-retrospective analysis of an outbreak in the burn centre Aachen.

    PubMed

    Fuchs, Paul Ch; Kopp, Jürgen; Häfner, Helga; Kleiner, Ullrich; Pallua, Norbert

    2002-09-01

    The growing interest in methicillin-resistant Staphylococcus aureus (MRSA) has been caused by its increased appearance in hospital and community populations. In our burn centre, an outbreak of MRSA was noticed during an 8-month period. We were able to isolate MRSA in eight patients. DNA analysis by pulsed-field gel electrophoresis (PFGE) demonstrated the development of five different strains during this period. Only two patients developed an infection caused by MRSA colonisation. The infections were proven by positive blood culture or catheter colonisation. One patient developed a clinical vancomycin-resistant sepsis which was treated successfully with the additional application of Quinupristin/Dalfopristin. THIS ANALYSIS SHOWS THAT: (1) the development of MRSA in a burn unit is often created in a single patient by long-term antibiotic therapy and not a result of cross-infection, (2) manifest MRSA infection seldom occurs even in colonised burn patients, and (3) a clinically vancomycin-resistant MRSA infection in burn patients can be treated sufficiently with Quinupristin/Dalfopristin.

  11. The Efficiency of Biofilters at Mitigating Airborne MRSA from a Swine Nursery.

    PubMed

    Ferguson, D D; Smith, T C; Donham, K J; Hoff, S J

    2015-10-01

    Our prior studies have been in agreement with other researchers in detecting airborne methicillin-resistant Staphylococcus aureus (MRSA) inside and downwind of a swine housing facility. MRSA emitted in the exhaust air of swine facilities creates a potential risk of transmission of these organisms to people in the general area of these facilities as well as to other animals. This study investigated a possible means of reducing those risks. We investigated the efficiency of biofilters to remove MRSA from the exhaust air of a swine building. Two types of biofilter media (hardwood chips and western red cedar shredded bark) were evaluated. Efficiency was measured by assessing both viable MRSA (viable cascade impactor) and dust particles (optical particle courter) in the pre-filtered and post-filtered air of a functioning swine production facility. Our study revealed that hardwood chips were respectively 92% and 88% efficient in removing viable MRSA and total dust particles. Western red cedar was 95% efficient in removing viable MRSA and 86% efficient in removing dust particles. Our findings suggest that biofilters can be used as effective engineering controls to mitigate the transmission of aerosolized MRSA in the exhaust air of enclosed swine housing facilities.

  12. Synergistic, collaterally sensitive β-lactam combinations suppress resistance in MRSA

    PubMed Central

    Gonzales, Patrick R.; Pesesky, Mitchell W.; Bouley, Renee; Ballard, Anna; Biddy, Brent A.; Suckow, Mark A.; Wolter, William R.; Schroeder, Valerie A.; Burnham, Carey-Ann D.; Mobashery, Shahriar; Chang, Mayland; Dantas, Gautam

    2015-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most prevalent multidrug-resistant pathogens worldwide, exhibiting increasing resistance to the latest antibiotic therapies. Here we show that the triple β-lactam combination meropenem/piperacillin/tazobactam (ME/PI/TZ) acts synergistically and is bactericidal against MRSA N315 and 72 clinical MRSA isolates in vitro, and clears MRSA N315 infection in a mouse model. ME/PI/TZ suppresses evolution of resistance in MRSA via reciprocal collateral sensitivity of its constituents. We demonstrate that these activities also extend to other carbapenem/penicillin/β-lactamase inhibitor combinations. ME/PI/TZ circumvents the tight regulation of the mec and bla operons in MRSA, the basis for inducible resistance to β-lactam antibiotics. Furthermore, ME/PI/TZ subverts the function of penicillin-binding protein 2a (PBP2a) action via allostery, which we propose as the mechanism for both synergy and collateral sensitivity. Showing similar in vivo activity to linezolid, ME/PI/TZ demonstrates that combinations of older β-lactam antibiotics could be effective against MRSA infections in humans. PMID:26368589

  13. In Vivo Effect of Flucloxacillin in Experimental Endocarditis Caused by mecC-positive Staphylococcus aureus Showing Temperature-Dependent Susceptibility In Vitro

    PubMed Central

    Mancini, Stefano; Laurent, Frédéric; Veloso, Tiago R.; Giddey, Marlyse; Vouillamoz, Jacques; Vandenesch, François; Moreillon, Philippe

    2015-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) carrying the mecC gene (mecC-MRSA) exhibited at 37°C MICs of oxacillin close to those of methicillin-susceptible S. aureus (MSSA). We investigated whether at this temperature, mecC-MRSA strains respond to flucloxacillin treatment like MSSA strains, using a rat model of endocarditis. Flucloxacillin (human-like kinetics of 2 g intravenously every 6 h) cured 80 to 100% of aortic vegetations infected with five different mecC-MRSA strains. These results suggest that mecC-MRSA infections may successfully respond to treatment with β-lactams. PMID:25605361

  14. Phenotypic and genotypic antimicrobial resistance traits of foodborne Staphylococcus aureus isolates from Shanghai

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Staphylococcus aureus is a recognized pathogen in humans, which causes nosocomial infections and food poisoning. The transmission of antibiotic resistant S. aureus (ARSA), especially methicillin-resistant S. aureus (MRSA), between food products and humans has become a serious problem. Hence, it is n...

  15. Monoclonal Antibody Targeting Staphylococcus aureus Surface Protein A (SasA) Protect Against Staphylococcus aureus Sepsis and Peritonitis in Mice.

    PubMed

    Yang, Yilong; Qian, Mengying; Yi, Shaoqiong; Liu, Shuling; Li, Bing; Yu, Rui; Guo, Qiang; Zhang, Xiaopeng; Yu, Changming; Li, Jianmin; Xu, Junjie; Chen, Wei

    2016-01-01

    Epidemic methicillin-resistant Staphylococcus aureus (MRSA) imposes an increasing impact on public health. Due to multi-antibiotics resistance in MRSA strains, there is an urgent need to develop novel therapeutics such as effective monoclonal antibodies (mAbs) against MRSA infections. Staphylococcus aureus surface protein A (SasA), a large surface-located protein (~240 kDa), is one of MSCRAMMs (microbial surface components recognizing adhesive matrix molecules) and a potential target for immunotherapeutic approaches against S. aureus infections. In the present study, we analyzed the sequence of SasA with bioinformatics tools and generated a protective monoclonal antibody (2H7) targeting the conserved domain of SasA. 2H7 was shown to recognize wild-type S. aureus and promote opsonophagocytic killing of S. aureus. In both sepsis and peritoneal infection models, prophylactic administration of 2H7 improved the survival of BALB/c mice challenged by S. aureus strain USA300 and ST239 (prevalent MRSA clones in North America and Asian countries, respectively) and enhanced bacterial clearance in kidneys. Additionally, 2H7 prophylaxis prevented the formation of intraperitoneal abscess in a murine model of peritoneal infection and therapeutic administration of 2H7 showed protective efficacy in a murine sepsis model. Our results presented here provide supporting evidences that an anti-SasA mAb might be a potential component in an antibody-based immunotherapeutic treatment of MRSA infections. PMID:26926145

  16. Monoclonal Antibody Targeting Staphylococcus aureus Surface Protein A (SasA) Protect Against Staphylococcus aureus Sepsis and Peritonitis in Mice.

    PubMed

    Yang, Yilong; Qian, Mengying; Yi, Shaoqiong; Liu, Shuling; Li, Bing; Yu, Rui; Guo, Qiang; Zhang, Xiaopeng; Yu, Changming; Li, Jianmin; Xu, Junjie; Chen, Wei

    2016-01-01

    Epidemic methicillin-resistant Staphylococcus aureus (MRSA) imposes an increasing impact on public health. Due to multi-antibiotics resistance in MRSA strains, there is an urgent need to develop novel therapeutics such as effective monoclonal antibodies (mAbs) against MRSA infections. Staphylococcus aureus surface protein A (SasA), a large surface-located protein (~240 kDa), is one of MSCRAMMs (microbial surface components recognizing adhesive matrix molecules) and a potential target for immunotherapeutic approaches against S. aureus infections. In the present study, we analyzed the sequence of SasA with bioinformatics tools and generated a protective monoclonal antibody (2H7) targeting the conserved domain of SasA. 2H7 was shown to recognize wild-type S. aureus and promote opsonophagocytic killing of S. aureus. In both sepsis and peritoneal infection models, prophylactic administration of 2H7 improved the survival of BALB/c mice challenged by S. aureus strain USA300 and ST239 (prevalent MRSA clones in North America and Asian countries, respectively) and enhanced bacterial clearance in kidneys. Additionally, 2H7 prophylaxis prevented the formation of intraperitoneal abscess in a murine model of peritoneal infection and therapeutic administration of 2H7 showed protective efficacy in a murine sepsis model. Our results presented here provide supporting evidences that an anti-SasA mAb might be a potential component in an antibody-based immunotherapeutic treatment of MRSA infections.

  17. Community-associated methicillin-resistant Staphylococcus aureus

    PubMed Central

    DeLeo, Frank R.; Otto, Michael; Kreiswirth, Barry N.; Chambers, Henry F.

    2012-01-01

    Summary Methicillin-resistant Staphylococcus aureus (MRSA) is endemic in hospitals worldwide and a significant cause of morbidity and mortality. Healthcare-associated MRSA infections occur in individuals with predisposing risk factors for disease, such as surgery or presence of an indwelling medical device. By contrast, community-associated MRSA (CA-MRSA) infections often occur in otherwise healthy individuals who lack such risk factors. In addition, CA-MRSA infections are epidemic in some countries. These observations suggest that CA-MRSA strains are more virulent and transmissible than traditional hospital-associated MRSA strains. Relatively limited treatment options for CA-MRSA infections compound the problem of enhanced virulence and transmission. Although progress has been made toward understanding emergence of CA-MRSA, virulence, and treatment of infections, our knowledge in these areas remains incomplete. Here were review the most current knowledge in these areas and provide perspective on future outlook for prophylaxis and/or new therapies for CA-MRSA infections. PMID:20206987

  18. Enhanced efficacy and anti-biofilm activity of novel nanoemulsions against skin burn wound multi-drug resistant MRSA infections.

    PubMed

    Song, Zhen; Sun, Hongwu; Yang, Yun; Jing, Haiming; Yang, Liuyang; Tong, Yanan; Wei, Chao; Wang, Zelin; Zou, Quanming; Zeng, Hao

    2016-08-01

    Multi-drug resistant MRSA (methicillin-resistant Staphylococcus aureus) is a global problem for human health, especially skin burn wound patients. Therefore, we estimated the antibacterial and anti-biofilm activity of a chlorhexidine acetate nanoemulsion (CNE) by previously ourselves designed against skin burn wound MRSA infections. Compared with its water solution (CHX), CNE showed a better and faster action against MRSA both in vitro and in vivo. Importantly, CNE was more effective at inhibiting biofilm formation and clearing the biofilm. We also found that the cell walls and membranes of MRSA were severely disrupted after treatment with CNE. Moreover, the relative electrical conductivity and the leakage of alkaline phosphates, K(+), Mg(2+), DNA and protein obviously increased because the cell wall and membrane were damaged. These data show that novel CNE is a promising potential antimicrobial candidate, especially for skin burn wound MRSA infections.

  19. IVIG-mediated protection against necrotizing pneumonia caused by MRSA.

    PubMed

    Diep, Binh An; Le, Vien T M; Badiou, Cedric; Le, Hoan N; Pinheiro, Marcos Gabriel; Duong, Au H; Wang, Xing; Dip, Etyene Castro; Aguiar-Alves, Fábio; Basuino, Li; Marbach, Helene; Mai, Thuy T; Sarda, Marie N; Kajikawa, Osamu; Matute-Bello, Gustavo; Tkaczyk, Christine; Rasigade, Jean-Philippe; Sellman, Bret R; Chambers, Henry F; Lina, Gerard

    2016-09-21

    New therapeutic approaches are urgently needed to improve survival outcomes for patients with necrotizing pneumonia caused by Staphylococcus aureus One such approach is adjunctive treatment with intravenous immunoglobulin (IVIG), but clinical practice guidelines offer conflicting recommendations. In a preclinical rabbit model, prophylaxis with IVIG conferred protection against necrotizing pneumonia caused by five different epidemic strains of community-associated methicillin-resistant S. aureus (MRSA) as well as a widespread strain of hospital-associated MRSA. Treatment with IVIG, either alone or in combination with vancomycin or linezolid, improved survival outcomes in this rabbit model. Two specific IVIG antibodies that neutralized the toxic effects of α-hemolysin (Hla) and Panton-Valentine leukocidin (PVL) conferred protection against necrotizing pneumonia in the rabbit model. This mechanism of action of IVIG was uncovered by analyzing loss-of-function mutant bacterial strains containing deletions in 17 genes encoding staphylococcal exotoxins, which revealed only Hla and PVL as having an impact on necrotizing pneumonia. These results demonstrate the potential clinical utility of IVIG in the treatment of severe pneumonia induced by S. aureus. PMID:27655850

  20. Draft Genome Sequences of Three Northern German Epidemic Staphylococcus aureus (ST247) Strains Containing Multiple Copies of IS256

    PubMed Central

    Kleinert, Franziska; Kallies, René; Zweynert, Annegret

    2016-01-01

    We report the draft genome sequences of three multiresistant Staphylococcus aureus strains of sequence type 247 (ST247). The methicillin-resistant S. aureus (MRSA) SA1450/94 is vancomycin susceptible, while the clinical MRSA isolate S. aureus SA137/93A and its spontaneous laboratory mutant SA137/93G are characterized by intermediate vancomycin susceptibility. PMID:27609917

  1. Draft Genome Sequences of Three Northern German Epidemic Staphylococcus aureus (ST247) Strains Containing Multiple Copies of IS256.

    PubMed

    Kleinert, Franziska; Kallies, René; Zweynert, Annegret; Bierbaum, Gabriele

    2016-01-01

    We report the draft genome sequences of three multiresistant Staphylococcus aureus strains of sequence type 247 (ST247). The methicillin-resistant S. aureus (MRSA) SA1450/94 is vancomycin susceptible, while the clinical MRSA isolate S. aureus SA137/93A and its spontaneous laboratory mutant SA137/93G are characterized by intermediate vancomycin susceptibility. PMID:27609917

  2. Investigational drugs to treat methicillin-resistant Staphylococcus aureus

    PubMed Central

    Vuong, Cuong; Yeh, Anthony J; Cheung, Gordon YC; Otto, Michael

    2016-01-01

    Introduction Staphylococcus aureus remains one of the leading causes of morbidity and mortality worldwide. This is to a large extent due to antibiotic-resistant strains, in particular methicillin-resistant S. aureus (MRSA). While the toll of invasive MRSA infections appears to decrease in U.S. hospitals, the rate of community-associated MRSA infections remains constant and there is a surge of MRSA in many other countries. This situation calls for continuing if not increased efforts to find novel strategies to combat MRSA infections. Areas covered This review will provide an overview of current investigational antibiotics in clinical development (up to phase II), and of therapeutic antibodies and alternative drugs against S. aureus in preclinical and clinical development, including a short description of the mechanism of action and a presentation of microbiological and clinical data. Expert opinion Increased recent antibiotic development efforts and results from pathogenesis research have led to several new antibiotics and alternative drugs, as well as a more informed selection of targets for vaccination efforts against MRSA. This developing portfolio of novel anti-staphylococcal drugs will hopefully provide us with additional and more efficient ways to combat MRSA infections in the near future and prevent us from running out of treatment options, even if new resistances arise. PMID:26536498

  3. Epidemiology of MRSA and current strategies in Europe and Japan

    PubMed Central

    Kramer, Axel; Wagenvoort, Hans; Åhrén, Christina; Daniels-Haardt, Inka; Hartemann, Philippe; Kobayashi, Hiro; Kurcz, Andrea; Picazo, Juan; Privitera, Gaetano; Assadian, Ojan

    2010-01-01

    The prevalence of health-care associated infections caused by multi-drug resistant organisms has significantly increased over the past decade. Among these organisms, Methicillin-resistant Staphylococcus aureus (MRSA) plays a prominent and increasing role. Because of consequences for patients and the economic burden in course of prolonged treatment following MRSA infections and additional indirect costs for e.g. isolation or antiseptic treatment, this trend will further damage European health-care systems. In 2006, a workshop was initiated at the 8th International Congress of the German Society of Hospital Hygiene held in Berlin. The aim of this workshop was to give an overview of the current situation of MRSA in selected European countries and to elaborate on potential strategies to prevent MRSA-infections and dissemination. A questionnaire encompassing 20 questions addressed topics such as epidemiology, current measures and future prospects was distributed to representatives from various European countries and Japan. A variety of widely different answers was obtained. It was shown that in all countries prevalence of MRSA is on a rising tide. This trend is observable in all European countries, albeit less strong in The Netherlands, Slovenia, France, Austria and Scandinavian countries. It was conclude that prevention strategies in a united and expanding European Community will become of utmost importance and that rapid screening strategies, e.g. PCR, might be of assistance in such an approach. A potential strategy to improve infection control measures could be the requirement of health-insurance providers to sign contracts only with hospitals able to proof having an infection control management in place. PMID:20204100

  4. Livestock-Associated MRSA in Household Members of Pig Farmers: Transmission and Dynamics of Carriage, A Prospective Cohort Study

    PubMed Central

    van Cleef, Brigitte A. G. L.; van Benthem, Birgit H. B.; Verkade, Erwin J. M.; van Rijen, Miranda M. L.; Kluytmans-van den Bergh, Marjolein F. Q.; Graveland, Haitske; Bosch, Thijs; Verstappen, Koen M. H. W.; Wagenaar, Jaap A.; Bos, Marian E. H.; Heederik, Dick; Kluytmans, Jan A. J. W.

    2015-01-01

    This prospective cohort study describes carriage of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in household members from 49 farrowing pig farms in the Netherlands (2010–2011). Of 171 household members, 4% were persistent MRSA nasal carriers, and the MRSA prevalence on any given sampling moment was 10% (range 7-11%). Working in the stables (of which 98% was MRSA-positive, prevalence ratio (PR) = 2.11 per 10 hours), working with sows (PR=1.97), and living with an MRSA-positive pig farmer (PR=4.63) were significant determinants for MRSA carriage. Significant protective factors were carriage of methicillin-susceptible Staphylococcus aureus (MSSA) (PR=0.50), and wearing a facemask when working in the stables (37% decreased prevalence). All MRSA strains during the study period were known livestock-associated types. The bacteriophage φ3 was not found in household members. Transmission from pigs and the environment appeared to be important determinants; human-to-human transmission could not sufficiently be differentiated. Wearing a facemask when working in the stables and carriage of MSSA are potential interventional targets. PMID:25993665

  5. Screening for detection of methicillin-resistant Staphylococcus aureus in Doon Valley Hospitals, Uttarakhand.

    PubMed

    Talwar, Amitabh; Saxena, Seema; Kumar, Ajay

    2016-03-01

    Present study was conducted to assess the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) among patients at various hospitals in Doon Valley, Uttrakhand. A total of 300 nasal swabs (male patients: 177, female patients: 123) were subjected to bacteriological investigation following established protocol. Isolates were verified by mannitol fermentation, Gram staining, DNAse test and coagulase positivity. S aureus was isolated in 111 (37%) participants (M: 37%, F: 36.5%). Out of 111 S. aureus isolates, 38 (34.2%) were methicillin resistant (MRSA). Among them, 25 (38%) were male and 13 (29%) were from female. Highest MRSA colonization rate was found among dialysis ward patients (55.5%), followed by burn ward (32.5%) and general medical ward (22.7%) patients. The study also revealed that administration of recent antibiotic was chief predisposing factor for MRSA colonization. High MRSA carriage rate found in this study indicates demand for standard infection control to curb transmission. PMID:27097444

  6. Screening for detection of methicillin-resistant Staphylococcus aureus in Doon Valley Hospitals, Uttarakhand.

    PubMed

    Talwar, Amitabh; Saxena, Seema; Kumar, Ajay

    2016-03-01

    Present study was conducted to assess the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) among patients at various hospitals in Doon Valley, Uttrakhand. A total of 300 nasal swabs (male patients: 177, female patients: 123) were subjected to bacteriological investigation following established protocol. Isolates were verified by mannitol fermentation, Gram staining, DNAse test and coagulase positivity. S aureus was isolated in 111 (37%) participants (M: 37%, F: 36.5%). Out of 111 S. aureus isolates, 38 (34.2%) were methicillin resistant (MRSA). Among them, 25 (38%) were male and 13 (29%) were from female. Highest MRSA colonization rate was found among dialysis ward patients (55.5%), followed by burn ward (32.5%) and general medical ward (22.7%) patients. The study also revealed that administration of recent antibiotic was chief predisposing factor for MRSA colonization. High MRSA carriage rate found in this study indicates demand for standard infection control to curb transmission.

  7. A study of community-associated methicillin-resistant Staphylococcus aureus in patients with pyoderma

    PubMed Central

    Venniyil, Prasanth V.; Ganguly, Satyaki; Kuruvila, Sheela; Devi, Sheela

    2016-01-01

    Background: Health care–associated methicillin-resistant Staphylococcus aureus(HA-MRSA) are resistant to multiple antibiotics, therefore infections caused by them are difficult to treat resulting in high morbidity and mortality. While most of the research activities and public health initiatives are focused on HA-MRSA, the newly emerging pathogen, community-associated methicillin-resistant Staphylococcus aureus(CA-MRSA) is gaining in significance in respect to patient morbidity. There is a significant paucity of data regarding CA-MRSA in the developing parts of the world. Aim: To study the proportions of HA-MRSA and CA-MRSA infections among patients with culture-proven S. aureus infection and to find out how many of these patients showed presence of MRSA in nasal cultures of healthy contacts. Materials and Methods: Clinical details of 227 patients were recorded in the study, such as the duration and recurrence of the infection, history of antibiotic intake, and the presence of other medical illnesses. A pus swab was taken from each lesion and sent for culture and sensitivity. If the culture grew S. aureus, they were screened for methicillin resistance. A swab from the anterior nares of the healthy contact of each patient, whenever available, was collected and it was screened for MRSA. Results: Furunculosis was most common among the primary pyodermas (53/134; 39. 5%). Out of 239 pus culture samples obtained from 227 patients, 192 (84.58%) grew S. aureus; of these 150 (78.12%) were methicillin-sensitive S. aureus (MSSA), whereas 42 (21.98%) were MRSA. Out of the 42 MRSA isolated, 33 turned out to be CA-MRSA (78%) and 9 (22%) were HA-MRSA. Nasal swabs of healthy contacts of 34 MRSA patients were cultured. Out of them, two grew MRSA in the culture. Conclusion: The isolation rate of S. aureus was high in our study. Furthermore, our study, although hospital based, clearly indicated the substantial magnitude of the CA-MRSA problem in the local population. PMID:27294048

  8. Imported Methicillin-Resistant Staphylococcus aureus, Sweden

    PubMed Central

    Örtqvist, Åke; Ringberg, Håkan; Larsson, Leif; Olsson-Liljequist, Barbro; Hæggman, Sara; Kalin, Mats; Ekdahl, Karl

    2010-01-01

    Countries such as Sweden that have a low prevalence of methicillin-resistant Staphylococcus aureus (MRSA) offer the opportunity to discern and study transmission of imported cases of MRSA. We analyzed 444 imported cases of MRSA acquisition reported in Sweden during 2000–2003. Risk for MRSA in returning travelers ranged from 0.1 (95% confidence interval [CI] 0.01–0.4) per 1 million travelers to Nordic countries to 59.4 (95% CI 44.5–79.3) per 1 million travelers to North Africa and the Middle East. Most imported cases (246, 55%) were healthcare acquired, but regions with the highest risk for MRSA in travelers showed a correlation with community acquisition (r = 0.81, p = 0.001). Characteristic differences in MRSA strains acquired were dependent on the region from which they originated and whether they were community or healthcare acquired. Knowledge of differences in transmission of MRSA may improve control measures against imported cases. PMID:20113546

  9. Community-acquired methicillin-resistant Staphylococcus aureus: community transmission, pathogenesis, and drug resistance.

    PubMed

    Yamamoto, Tatsuo; Nishiyama, Akihito; Takano, Tomomi; Yabe, Shizuka; Higuchi, Wataru; Razvina, Olga; Shi, Da

    2010-08-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is able to persist not only in hospitals (with a high level of antimicrobial agent use) but also in the community (with a low level of antimicrobial agent use). The former is called hospital-acquired MRSA (HA-MRSA) and the latter community-acquired MRSA (CA-MRSA). It is believed MRSA clones are generated from S. aureus through insertion of the staphylococcal cassette chromosome mec (SCCmec), and outbreaks occur as they spread. Several worldwide and regional clones have been identified, and their epidemiological, clinical, and genetic characteristics have been described. CA-MRSA is likely able to survive in the community because of suitable SCCmec types (type IV or V), a clone-specific colonization/infection nature, toxin profiles (including Pantone-Valentine leucocidin, PVL), and narrow drug resistance patterns. CA-MRSA infections are generally seen in healthy children or young athletes, with unexpected cases of diseases, and also in elderly inpatients, occasionally surprising clinicians used to HA-MRSA infections. CA-MRSA spreads within families and close-contact groups or even through public transport, demonstrating transmission cores. Re-infection (including multifocal infection) frequently occurs, if the cores are not sought out and properly eradicated. Recently, attention has been given to CA-MRSA (USA300), which originated in the US, and is growing as HA-MRSA and also as a worldwide clone. CA-MRSA infection in influenza season has increasingly been noted as well. MRSA is also found in farm and companion animals, and has occasionally transferred to humans. As such, the epidemiological, clinical, and genetic behavior of CA-MRSA, a growing threat, is focused on in this study. PMID:20336341

  10. PSMs of Hypervirulent Staphylococcus aureus Act as Intracellular Toxins That Kill Infected Osteoblasts

    PubMed Central

    Rasigade, Jean-Philippe; Trouillet-Assant, Sophie; Ferry, Tristan; Diep, Binh An; Sapin, Anaïs; Lhoste, Yannick; Ranfaing, Jérémy; Badiou, Cédric; Benito, Yvonne; Bes, Michèle; Couzon, Florence; Tigaud, Sylvestre; Lina, Gérard; Etienne, Jérôme; Vandenesch, François; Laurent, Frédéric

    2013-01-01

    Epidemic community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) is associated with more severe and acute forms of osteomyelitis than healthcare-associated (HA-) MRSA. Although S. aureus is now recognized as a facultative intracellular pathogen, the contribution of osteoblast invasion by CA-MRSA to the pathogenesis of osteomyelitis is unknown. Using an ex vivo model of intracellular infection of human osteoblasts, we demonstrated that CA-MRSA strains of diverse lineages share an enhanced ability to kill infected osteoblasts compared to HA-MRSA. Cytotoxicity comparisons of CA-MRSA isogenic deletion mutants revealed that phenol-soluble modulins (PSMs), a class of membrane-damaging exoproteins that are expressed at higher levels in CA-MRSA than in HA-MRSA, are involved in this osteoblast killing, whereas other major CA-MRSA virulence determinants, the Panton-Valentine leukocidin and alpha-toxin, are not involved. Similarly, functional agr and sarA regulators, which control the expression of PSMs and alpha-toxin, were required for the expression of the intracellular cytotoxic phenotype by CA-MRSA, whereas the saeRS regulator, which controls the expression of alpha-toxin but not PSMs, had no impact on cytotoxicity. Finally, PSM transcript levels determined by quantitative reverse-transcriptase PCR were significantly higher in CA-MRSA than in HA-MRSA strains and associated with cell damage in MRSA-infected osteoblasts. These findings provide new insights into the pathogenesis of severe CA-MRSA osteomyelitis and unravel a novel virulence strategy of CA-MRSA, based on the invasion and subsequent killing of osteoblasts by PSMs acting as intracellular toxins. PMID:23690994

  11. Risk factors for MRSA in fattening pig herds - a meta-analysis using pooled data.

    PubMed

    Fromm, Sabine; Beißwanger, Elena; Käsbohrer, Annemarie; Tenhagen, Bernd-Alois

    2014-11-01

    The importance of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) as an infectious agent for humans has increased in recent years in Germany. Although it is well known that the prevalence of MRSA in pig farms is high, risk factors for the presence of MRSA in herds of fattening pigs are still poorly understood. The aim of this study was to evaluate available data from previous studies on MRSA in fattening pigs in a meta-analysis to answer the question: What are the factors associated with the occurrence of MRSA in fattening pig herds? The studies on MRSA in pigs that were identified by literature research were heterogeneous with respect to the risk factors investigated and the type of herds focused on. Therefore we decided to carry out a pooling analysis on herd level rather than a typical meta-analysis. Eligible herd data were identified based on the published literature and communication with the authors. The final data set covered 400 fattening pig herds from 10 different studies and 12 risk factors. The prevalence of MRSA in the 400 fattening pig herds was 53.5%. Data were analyzed using generalized estimating equations (GEE). The resulting multivariate model confirmed previously identified risk factors for MRSA in pig herds (herd size and herd type). It also identified further risk factors: group treatment of fattening pigs with antimicrobial drugs (OR=1.79) and housing fattening pig herds on at least partially slatted floors (OR=2.39) compared to plain floor. In contrast, according to the model, fattening pig herds on farms keeping other livestock along with pigs were less likely to harbor MRSA (OR=0.54). The results underline the benefits from a pooling analysis and cooperative re-evaluation of published data.

  12. Reduction in MRSA environmental contamination with a portable HEPA-filtration unit.

    PubMed

    Boswell, T C; Fox, P C

    2006-05-01

    There is renewed interest in the hospital environment as a potentially important factor for cross-infection with methicillin-resistant Staphylococcus aureus (MRSA) and other nosocomial pathogens. The aim of this study was to evaluate the effectiveness of a portable high-efficiency particulate air (HEPA)-filtration unit (IQAir Cleanroom H13, Incen AG, Goldach, Switzerland) at reducing MRSA environmental surface contamination within a clinical setting. The MRSA contamination rate on horizontal surfaces was assessed with agar settle plates in ward side-rooms of three patients who were heavy MRSA dispersers. Contamination rates were measured at different air filtration rates (60-235 m(3)/h) and compared with no air filtration using Poisson regression. Without air filtration, between 80% and 100% of settle plates were positive for MRSA, with the mean number of MRSA colony-forming units (cfu)/10-h exposure/plate ranging from 4.1 to 27.7. Air filtration at a rate of 140 m(3)/h (one patient) and 235 m(3)/h (two patients), resulted in a highly significant decrease in contamination rates compared with no air filtration (adjusted rate ratios 0.037, 0.099 and 0.248, respectively; P < 0.001 for each). A strong association was demonstrated between the rate of air filtration and the mean number of MRSA cfu/10-h exposure/plate (P for trend < 0.001). In conclusion, this portable HEPA-filtration unit can significantly reduce MRSA environmental contamination within patient isolation rooms, and this may prove to be a useful addition to existing MRSA infection control measures.

  13. The Rise of Methicillin-Resistant Staphylococcus aureus in U.S. Correctional Populations

    PubMed Central

    Malcolm, Bianca

    2011-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is an emerging threat to public health, especially in correctional settings. Outbreaks have been seen in jails and prisons in Mississippi, California, Texas, and Georgia in recent years. Also, many correctional settings have seen an increase in MRSA infection greater than in the general population. This article examines the lessons that have been learned about MRSA in correctional settings and ponders what is yet to be learned about this disease in these populations. PMID:21571749

  14. Community-acquired methicillin resistant Staphylococcus aureus in a women's collegiate basketball team.

    PubMed

    Stevens, Michael P; Bearman, Gonzalo; Rosato, Adriana; Edmond, Michael

    2008-10-01

    Community-acquired methicillin resistant Staphylococcus aureus (CA-MRSA) infections are becoming increasingly frequent, and cutaneous disease with this organism is often seen in otherwise healthy organized sports participants. A case of CA-MRSA skin and soft tissue infection in a female collegiate basketball player is presented, and screening and management of her team is discussed. Interestingly, multiple MRSA strains were discovered on testing of the team, raising concern that the prevalence of colonization in this population may be high.

  15. Immunomodulatory effects of recombinant lactoferrin during MRSA infection

    PubMed Central

    Hwang, Shen-An; Kruzel, Marian L.; Actor, Jeffrey K.

    2014-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) infection remains a serious hazard to global health despite increases in public education and development of innovative treatment strategies. Use of immune modulatory therapy to combat infection is gaining interest as a novel treatment alternative. Lactoferrin (LF), an iron binding protein with multiple immune modulating properties, has the potential to modify the course of systemic MRSA infection. Specifically, LF is capable of limiting deleterious inflammatory responses while promoting development of antigen specific T-cell activity. The efficacy of a novel recombinant mouse LF (rmLF) to protect against MRSA infection was examined in a mouse peritonitis model. BALB/c mice were infected with a lethal dose of MRSA and treated at 2 hours post-infection with rmLF. The effects of rmLF on MRSA-infected primary monocytes and granulocytes were analyzed for inflammatory mediator production. The rmLF treated mice demonstrated only modest increase in survival by more than 24hrs, albeit with reduced bacteremia. Serum cytokines, IL-17 and IL-6, were significantly reduced post challenge in the rmLF treated mice. Treatment with rmLF led to a minor decrease in IL-1β, and a slight increase in TNF-α production. Preliminary investigation towards human clinical relevance was accomplished using human blood derived monocytes and granulocytes infected with MRSA and treated with a homologous recombinant human LF (rhLF). Treatment with (rhLF) led to increased production of IFN-γ and IL-2. The human cell studies also showed a concurrent decrease in TNF-α, IL-6, IL-1β, IL-12p40, and IL-10. The study reports the first investigation into the efficacy of a novel recombinant mouse lactoferrin (LF) therapy in a mouse model of MRSA peritonitis. Overall, these results indicate the rmLF and rhLF have a high degree of overlap to modify inflammatory responses, although differences in activities were observed indicating existence of mechanisms

  16. Evaluation of two commercially available chromogenic media for confirmation of methicillin-resistant Staphylococcus aureus from human, animal, and food samples.

    PubMed

    Ariza-Miguel, Jaime; Oniciuc, Elena-Alexandra; Sanz, Iván; Fernández-Natal, Isabel; Hernández, Marta; Rodríguez-Lázaro, David

    2015-09-16

    We compared the diagnostic performance of two chromogenic media, Brilliance MRSA 2 agar (Thermo Fisher Scientific) and ChromID MRSA agar (bioMérieux), for MRSA confirmation of 239 Staphylococcus aureus isolates from clinical, animal and food samples. Statistically significant differences were not observed between MRSA confirmation by mecA/mecC PCR, and by culture in both chromogenic media. However, a statistically significant difference was observed between the results obtained by both chromogenic media (p = 0.003). Segregated analysis of the results depending on the origin of the isolates (clinical, animal, and food) revealed a significant lower performance in the MRSA confirmation of food-derived isolates by using Brilliance MRSA 2 agar in comparison to PCR confirmation (p = 0.003) or ChromID MRSA agar (p<0.001). Both chromogenic media provided a good diagnostic performance for detection of MRSA isolates of human and animal origin. In conclusion, the use of chromogenic agar plates for MRSA confirmation of S. aureus isolates can provide a good diagnostic performance (sensitivity >92% and specificity >89%) regardless of the type of chromogenic media used or the origin of the S. aureus isolates. However, our results revealed a lower diagnostic performance for MRSA confirmation of S. aureus isolates from food samples by using Brilliance MRSA 2 agar.

  17. Prevalence of Staphylococcus aureus Colonization and Risk Factors for Infection Among Military Personnel in a Shipboard Setting.

    PubMed

    Curry, Jennifer A; Maguire, Jason D; Fraser, Jamie; Tribble, David R; Deiss, Robert G; Bryan, Coleman; Tisdale, Michele D; Crawford, Katrina; Ellis, Michael; Lalani, Tahaniyat

    2016-06-01

    Staphylococcal skin and soft tissue infections (SSTIs), especially those due to methicillin-resistant Staphylococcus aureus (MRSA) are an important public health issue for the military. Limited data exist regarding the prevalence of S. aureus colonization in the shipboard setting. We conducted a cross-sectional, observational study to determine the point prevalence of S. aureus colonization among military personnel onboard a naval vessel. Asymptomatic active duty personnel completed a survey for risk factors associated with colonization and SSTIs. Culture specimens were obtained from the anterior nares, pharynx, groin, and perirectal regions. MRSA isolates underwent testing for antimicrobial resistance, virulence factors, and pulsed-field type. 400 individuals were enrolled, 198 (49.5%) of whom were colonized with S. aureus, with MRSA identified in 14 participants (3.5%). No significant risk factors were associated with MRSA colonization. USA800 was the most common colonizing MRSA strain in the cohort and was detected in 10 participants (71%). Two participants (14%) were colonized with USA300 MRSA. In this first report of S. aureus epidemiology in a shipboard setting, we observed high rates of S. aureus and MRSA colonization. Longitudinal studies are needed to document the incident rates of S. aureus colonization during shipboard deployment and its impact on SSTI risk.

  18. Prevalence of Staphylococcus aureus Colonization and Risk Factors for Infection Among Military Personnel in a Shipboard Setting.

    PubMed

    Curry, Jennifer A; Maguire, Jason D; Fraser, Jamie; Tribble, David R; Deiss, Robert G; Bryan, Coleman; Tisdale, Michele D; Crawford, Katrina; Ellis, Michael; Lalani, Tahaniyat

    2016-06-01

    Staphylococcal skin and soft tissue infections (SSTIs), especially those due to methicillin-resistant Staphylococcus aureus (MRSA) are an important public health issue for the military. Limited data exist regarding the prevalence of S. aureus colonization in the shipboard setting. We conducted a cross-sectional, observational study to determine the point prevalence of S. aureus colonization among military personnel onboard a naval vessel. Asymptomatic active duty personnel completed a survey for risk factors associated with colonization and SSTIs. Culture specimens were obtained from the anterior nares, pharynx, groin, and perirectal regions. MRSA isolates underwent testing for antimicrobial resistance, virulence factors, and pulsed-field type. 400 individuals were enrolled, 198 (49.5%) of whom were colonized with S. aureus, with MRSA identified in 14 participants (3.5%). No significant risk factors were associated with MRSA colonization. USA800 was the most common colonizing MRSA strain in the cohort and was detected in 10 participants (71%). Two participants (14%) were colonized with USA300 MRSA. In this first report of S. aureus epidemiology in a shipboard setting, we observed high rates of S. aureus and MRSA colonization. Longitudinal studies are needed to document the incident rates of S. aureus colonization during shipboard deployment and its impact on SSTI risk. PMID:27244061

  19. Nasal colonization in children with community acquired methicillin-resistant Staphylococcus aureus

    PubMed Central

    Davoodabadi, Fazlollah; Mobasherizadeh, Sina; Mostafavizadeh, Kamyar; Shojaei, Hasan; Havaei, Seyed Asghar; Koushki, Ali Mehrabi; Moghadasizadeh, Zahra; Meidani, Mohsen; Shirani, Kiana

    2016-01-01

    Background: Methicillin-resistant Staphylococcus aureus (MRSA) is a frequent cause of infections. The changing epidemiology of MRSA became evident in the 1990s when CA-MRSA cases were first reported. Nasal carriage of CA-MRSA is associated with an increased risk for development of infections in various populations. Materials and Methods: Anterior nares culture for the presence of methicillin-susceptible Staphylococcus aureus (MSSA) and MRSA was taken from 345 children attending kindergartens, who didn’t have any known risk factor for MRSA colonization. Also, children demographic variables were recorded. Identification of SA and community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) with standard microbiological test was performed. Finally, the susceptibility of isolated to various antibiotics determined. The data were analyzed with Whonet 5.6 software. Results: Of 345 children, 20 children (5.8%) were colonized with CA-MRSA, 86 children (24.9%) with MSSA and 239 cases (69.3%) didn’t have SA colonization. The highest rate of MSSA and MRSA colonization was obtained at the age of 6 years. The frequency distribution of SA (MSSA and MRSA) colonization prevalence didn’t have any significant differences based on age, gender and the admission time (P > 0.05); but it was significantly different in the urban areas (P < 0.001). The lowest resistance rate of CA-MRSA isolates, with a frequency of 10%, was detected with gentamicin, rifampin, and trimethoprim-sulfamethoxazole. Conclusions: In summary, CA-MRSA colonization was observed in child care centers remarkably. Therefore, by facing various infections due to SA especially in areas of low socio-economic status, it must be considered. Based on antibiogram test, empirical treatment with rifampin, gentamicin and ciprofloxacin is recommended during CA-MRSA infections. PMID:27274501

  20. Methicillin-Resistant Staphylococcus aureus Associated with Animals and Its Relevance to Human Health.

    PubMed

    Pantosti, Annalisa

    2012-01-01

    Staphylococcus aureus is a typical human pathogen. Some animal S. aureus lineages have derived from human strains following profound genetic adaptation determining a change in host specificity. Due to the close relationship of animals with the environmental microbiome and resistome, animal staphylococcal strains also represent a source of resistance determinants. Methicillin-resistant S. aureus (MRSA) emerged 50 years ago as a nosocomial pathogen but in the last decade it has also become a frequent cause of infections in the community. The recent finding that MRSA frequently colonizes animals, especially livestock, has been a reason for concern, as it has revealed an expanded reservoir of MRSA. While MRSA strains recovered from companion animals are generally similar to human nosocomial MRSA, MRSA strains recovered from food animals appear to be specific animal-adapted clones. Since 2005, MRSA belonging to ST398 was recognized as a colonizer of pigs and human subjects professionally exposed to pig farming. The "pig" MRSA was also found to colonize other species of farmed animals, including horses, cattle, and poultry and was therefore designated livestock-associated (LA)-MRSA. LA-MRSA ST398 can cause infections in humans in contact with animals, and can infect hospitalized people, although at the moment this occurrence is relatively rare. Other animal-adapted MRSA clones have been detected in livestock, such as ST1 and ST9. Recently, ST130 MRSA isolated from bovine mastitis has been found to carry a novel mecA gene that eludes detection by conventional PCR tests. Similar ST130 strains have been isolated from human infections in UK, Denmark, and Germany at low frequency. It is plausible that the increased attention to animal MRSA will reveal other strains with peculiar characteristics that can pose a risk to human health.

  1. Occurrence of methicillin-resistant Staphylococcus aureus in surface waters near industrial hog operation spray fields.

    PubMed

    Hatcher, S M; Myers, K W; Heaney, C D; Larsen, J; Hall, D; Miller, M B; Stewart, J R

    2016-09-15

    Industrial hog operations (IHOs) have been identified as a source of antibiotic-resistant Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA). However, few studies have investigated the presence of antibiotic-resistant S. aureus in the environment near IHOs, specifically surface waters proximal to spray fields where IHO liquid lagoon waste is sprayed. Surface water samples (n=179) were collected over the course of approximately one year from nine locations in southeastern North Carolina and analyzed for the presence of presumptive MRSA using CHROMagar MRSA media. Culture-based, biochemical, and molecular tests, as well as matrix-assisted laser desorption/ionization-time of flight mass spectrometry were used to confirm that isolates that grew on CHROMagar MRSA media were S. aureus. Confirmed S. aureus isolates were then tested for susceptibility to 16 antibiotics and screened for molecular markers of MRSA (mecA, mecC) and livestock adaptation (absence of scn). A total of 12 confirmed MRSA were detected in 9 distinct water samples. Nine of 12 MRSA isolates were also multidrug-resistant (MDRSA [i.e., resistant to ≥3 antibiotic classes]). All MRSA were scn-positive and most (11/12) belonged to a staphylococcal protein A (spa) type t008, which is commonly associated with humans. Additionally, 12 confirmed S. aureus that were methicillin-susceptible (MSSA) were recovered, 7 of which belonged to spa type t021 and were scn-negative (a marker of livestock-adaptation). This study demonstrated the presence of MSSA, MRSA, and MDRSA in surface waters adjacent to IHO lagoon waste spray fields in southeastern North Carolina. To our knowledge, this is the first report of waterborne S. aureus from surface waters proximal to IHOs. PMID:27261430

  2. Occurrence of methicillin-resistant Staphylococcus aureus in surface waters near industrial hog operation spray fields.

    PubMed

    Hatcher, S M; Myers, K W; Heaney, C D; Larsen, J; Hall, D; Miller, M B; Stewart, J R

    2016-09-15

    Industrial hog operations (IHOs) have been identified as a source of antibiotic-resistant Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA). However, few studies have investigated the presence of antibiotic-resistant S. aureus in the environment near IHOs, specifically surface waters proximal to spray fields where IHO liquid lagoon waste is sprayed. Surface water samples (n=179) were collected over the course of approximately one year from nine locations in southeastern North Carolina and analyzed for the presence of presumptive MRSA using CHROMagar MRSA media. Culture-based, biochemical, and molecular tests, as well as matrix-assisted laser desorption/ionization-time of flight mass spectrometry were used to confirm that isolates that grew on CHROMagar MRSA media were S. aureus. Confirmed S. aureus isolates were then tested for susceptibility to 16 antibiotics and screened for molecular markers of MRSA (mecA, mecC) and livestock adaptation (absence of scn). A total of 12 confirmed MRSA were detected in 9 distinct water samples. Nine of 12 MRSA isolates were also multidrug-resistant (MDRSA [i.e., resistant to ≥3 antibiotic classes]). All MRSA were scn-positive and most (11/12) belonged to a staphylococcal protein A (spa) type t008, which is commonly associated with humans. Additionally, 12 confirmed S. aureus that were methicillin-susceptible (MSSA) were recovered, 7 of which belonged to spa type t021 and were scn-negative (a marker of livestock-adaptation). This study demonstrated the presence of MSSA, MRSA, and MDRSA in surface waters adjacent to IHO lagoon waste spray fields in southeastern North Carolina. To our knowledge, this is the first report of waterborne S. aureus from surface waters proximal to IHOs.

  3. VISA/VRSA (Vancomycin-Intermediate/Resistant Staphylococcus aureus) in Healthcare Settings

    MedlinePlus

    ... their bodies (such as catheters), previous infections with methicillin-resistant Staphylococcus aureus (MRSA), and recent exposure to vancomycin ... or VRSA? VISA and VRSA are types of antibiotic-resistant staph bacteria. Therefore, as with all staph bacteria, ...

  4. Epidemiology and genotypic characteristics of Methicillin-Resistant Staphylococcus aureus strains of porcine origin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The main goal of this study was to determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA), particularly livestock-associated (LA)-MRSA in pigs and pork. Genotypic relatedness of isolates on-farm, at slaughter and retail was assessed. Paired nasal and peri-anal swab samples we...

  5. Community-associated methicillin resistant Staphylococcus aureus in south Florida hospital and recreational environments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Strains of methicillin resistant Staphylococcus aureus (MRSA), a frequent human pathogen, may also be found in the flora of healthy persons and in the environments that they frequent. Strains of MRSA circulating in the community classified as USA 300 are now found not only in the community but also...

  6. Draft Genome Sequences of Two Methicillin-Resistant Clinical Staphylococcus aureus Isolates

    PubMed Central

    Sung, Kidon; Iram, Saira; Nawaz, Mohamed; Xu, Joshua

    2016-01-01

    Here, we report the draft genome sequences of two methicillin-resistant Staphylococcus aureus (MRSA) clinical isolates, hospital-associated perirectal isolate 32S (ST 239) from a colitis tracheostomy patient and community-associated MRSA isolate 42S (ST 772) from a hepatic-splenomegaly patient in Rawalpindi, Pakistan. PMID:26868381

  7. Epidemiological analysis of methicillin-resistant Staphylococcus aureus carriage among veterinary staff of companion animals in Japan.

    PubMed

    Ishihara, Kanako; Saito, Mieko; Shimokubo, Natsumi; Muramatsu, Yasukazu; Maetani, Shigeki; Tamura, Yutaka

    2014-12-01

    Veterinary staff carrying methicillin-resistant Staphylococcus aureus(MRSA) can be a source of MRSA infection in animals. To identify risk factors of MRSA carriage among veterinary staff, MRSA carriage and epidemiological information (sex, career, contact with MRSA-identified animal patients and others) were analyzed from 96 veterinarians and 70 veterinary technicians working at 71 private veterinary clinics in Japan. Univariate analysis determined sex (percentage of MRSA carriage, male (29.2%) vs. female (10%); P=0.002) and career (veterinarians (22.9%) vs. veterinary technicians (10%); P=0.030) as risk factors. Multivariable analysis revealed that sex was independently associated with MRSA carriage (adjusted odds ratio, 3.717; 95% confidence interval, 1.555-8.889; P=0.003). Therefore, male veterinary staff had a higher risk of MRSA carriage than female staff.

  8. Improved understanding of factors driving methicillin-resistant Staphylococcus aureus epidemic waves

    PubMed Central

    Chatterjee, Som S; Otto, Michael

    2013-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) remains one of the most important causes of nosocomial infections worldwide. Since the global spread of MRSA in the 1960s, MRSA strains have evolved with increased pathogenic potential. Notably, some strains are now capable of causing persistent infections not only in hospitalized patients but also in healthy individuals in the community. Furthermore, MRSA is increasingly associated with infections among livestock-associated workers, primarily because of transmission from animals to humans. Moreover, many MRSA strains have gained resistance to most available antibiotics. In this review, we will present current knowledge on MRSA epidemiology and discuss new endeavors being undertaken to understand better the molecular and epidemiological underpinnings of MRSA outbreaks. PMID:23861600

  9. Enteral vancomycin and probiotic use for methicillin-resistant Staphylococcus aureus antibiotic-associated diarrhoea.

    PubMed

    Sizemore, Elizabeth Nicole; Rivas, Kenya Maria; Valdes, Jose; Caballero, Joshua

    2012-07-27

    A geriatric patient status post intraabdominal surgery presented with persistent diarrhoea and heavy intestinal methicillin-resistant Staphylococcus aureus (MRSA) growth after multiple courses of antibiotic therapy. Additionally, swab cultures of the anterior nares tested positive for MRSA. In order to impede infection and prevent future complications, the patient received a 10-day course of vancomycin oral solution 250 mg every 6 h, 15-day course of Saccharomyces boulardii 250 mg orally twice daily and a 5-day course of topical mupirocin 2% twice daily intranasally. Diarrhoea ceased during therapy and repeat cultures 11 days after initiating therapy demonstrated negative MRSA growth from the stool and nares. Further repeat cultures 5 months later revealed negative MRSA growth in the stools and minimal MRSA growth in the nares. Overall, enteral vancomycin and probiotics successfully eradicated MRSA infection without intestinal recurrence. Although the results were beneficial treating MRSA diarrhoea for our patient, these agents remain highly controversial.

  10. Bioreductively Activated Reactive Oxygen Species (ROS) Generators as MRSA Inhibitors.

    PubMed

    Khodade, Vinayak S; Sharath Chandra, Mallojjala; Banerjee, Ankita; Lahiri, Surobhi; Pulipeta, Mallikarjuna; Rangarajan, Radha; Chakrapani, Harinath

    2014-07-10

    The number of cases of drug resistant Staphylococcus aureus infections is on the rise globally and new strategies to identify drug candidates with novel mechanisms of action are in urgent need. Here, we report the synthesis and evaluation of a series of benzo[b]phenanthridine-5,7,12(6H)-triones, which were designed based on redox-active natural products. We find that the in vitro inhibitory activity of 6-(prop-2-ynyl)benzo[b]phenanthridine-5,7,12(6H)-trione (1f) against methicillin-resistant Staphylococcus aureus (MRSA), including a panel of patient-derived strains, is comparable or better than vancomycin. We show that the lead compound generates reactive oxygen species (ROS) in the cell, contributing to its antibacterial activity. PMID:25050164

  11. Proteome-wide antigen discovery of novel protective vaccine candidates against Staphylococcus aureus infection.

    PubMed

    Rasmussen, Karina Juhl; Mattsson, Andreas Holm; Pilely, Katrine; Asferg, Cecilie Antoinette; Ciofu, Oana; Vitved, Lars; Koch, Claus; Kemp, Michael

    2016-08-31

    Methicillin-resistant Staphylococcus aureus (MRSA) is a rapidly growing problem, especially in hospitals where MRSA cause increased morbidity and mortality and a significant rise in health expenditures. As many strains of MRSA are resistant to other antimicrobials in addition to methicillin, there is an urgent need to institute non-antimicrobial measures, such as vaccination, against the spread of MRSA. With the aim of finding new protective antigens for vaccine development, this study used a proteome-wide in silico antigen prediction platform to screen the proteome of S. aureus strain MRSA252. Thirty-five different S. aureus proteins were identified, recombinantly expressed, and tested for protection in a lethal sepsis mouse model using S. aureus strain MRSA252 as the challenge organism. We found that 13 of the 35 recombinant peptides yielded significant protection and that 12 of these antigens were highly conserved across 70 completely sequenced S. aureus strains. Thus, this in silico platform was capable of identifying novel candidates for inclusion in future vaccines against MRSA. PMID:27496278

  12. Multiple B-cell epitope vaccine induces a Staphylococcus enterotoxin B-specific IgG1 protective response against MRSA infection.

    PubMed

    Zhao, Zhuo; Sun, He-Qiang; Wei, Shan-Shan; Li, Bin; Feng, Qiang; Zhu, Jiang; Zeng, Hao; Zou, Quan-Ming; Wu, Chao

    2015-01-01

    No vaccine against methicillin-resistant Staphylococcus aureus (MRSA) has been currently approved for use in humans. Staphylococcus enterotoxin B (SEB) is one of the most potent MRSA exotoxins. In the present study, we evaluated the efficacy and immunologic mechanisms of an SEB multiple B-cell epitope vaccine against MRSA infection. Synthetic overlapping peptide ELISA identified three novel B-cell immunodominant SEB epitopes (in addition to those previously known): SEB31-48, SEB133-150, and SEB193-210. Six B-cell immunodominant epitopes (amino acid residues 31-48, 97-114, 133-150, 193-210, 205-222, and 247-261) were sufficient to induce robust IgG1/IgG2b-specific protective responses against MRSA infection. Therefore, we constructed a recombinant MRSA SEB-specific multiple B-cell epitope vaccine Polypeptides by combining the six SEB immunodominant epitopes and demonstrated its ability to induce a robust SEB-specific IgG1 response to MRSA, as well as a Th2-directing isotype response. Moreover, Polypeptides-induced antisera stimulated synergetic opsonophagocytosis killing of MRSA. Most importantly, Polypeptides was more effective at clearing the bacteria in MRSA-infected mice than the whole SEB antigen, and was able to successfully protect mice from infection by various clinical MRSA isolates. Altogether, these results support further evaluation of the SEB multiple B-cell epitope-vaccine to address MRSA infection in humans.

  13. Multiple B-cell epitope vaccine induces a Staphylococcus enterotoxin B-specific IgG1 protective response against MRSA infection

    PubMed Central

    Zhao, Zhuo; Sun, He-Qiang; Wei, Shan-Shan; Li, Bin; Feng, Qiang; Zhu, Jiang; Zeng, Hao; Zou, Quan-Ming; Wu, Chao

    2015-01-01

    No vaccine against methicillin-resistant Staphylococcus aureus (MRSA) has been currently approved for use in humans. Staphylococcus enterotoxin B (SEB) is one of the most potent MRSA exotoxins. In the present study, we evaluated the efficacy and immunologic mechanisms of an SEB multiple B-cell epitope vaccine against MRSA infection. Synthetic overlapping peptide ELISA identified three novel B-cell immunodominant SEB epitopes (in addition to those previously known): SEB31–48, SEB133–150, and SEB193–210. Six B-cell immunodominant epitopes (amino acid residues 31–48, 97–114, 133–150, 193–210, 205–222, and 247–261) were sufficient to induce robust IgG1/IgG2b-specific protective responses against MRSA infection. Therefore, we constructed a recombinant MRSA SEB-specific multiple B-cell epitope vaccine Polypeptides by combining the six SEB immunodominant epitopes and demonstrated its ability to induce a robust SEB-specific IgG1 response to MRSA, as well as a Th2-directing isotype response. Moreover, Polypeptides-induced antisera stimulated synergetic opsonophagocytosis killing of MRSA. Most importantly, Polypeptides was more effective at clearing the bacteria in MRSA-infected mice than the whole SEB antigen, and was able to successfully protect mice from infection by various clinical MRSA isolates. Altogether, these results support further evaluation of the SEB multiple B-cell epitope-vaccine to address MRSA infection in humans. PMID:26201558

  14. MRSA Prevalence and Associated Risk Factors among Health-Care Workers in Non-outbreak Situations in the Dutch-German EUREGIO.

    PubMed

    Sassmannshausen, Ricarda; Deurenberg, Ruud H; Köck, Robin; Hendrix, Ron; Jurke, Annette; Rossen, John W A; Friedrich, Alexander W

    2016-01-01

    Preventing the spread of methicillin-resistant Staphylococcus aureus (MRSA) in healthcare facilities is a major infection control target. However, only a few studies have assessed the potential role of healthcare workers (HCWs) for MRSA dissemination. To investigate the MRSA prevalence and the risk factors for MRSA colonization among HCWs, nasopharyngeal swabs were taken between June 2010 and January 2011 from 726 employees from nine acute care hospitals with different care levels within the German part of a Dutch-German border region (EUREGIO). The isolated MRSA strains were investigated using spa typing. The overall MRSA prevalence among HCWs in a non-outbreak situation was 4.6% (33 of 726), and was higher in nurses (5.6%, 29 of 514) than in physicians (1.2%, 1 of 83). Possible risk factors associated with MRSA colonization were a known history of MRSA carriage and the presence of acne. Intensive contact with patients may facilitate MRSA transmission between patients and HCWs. Furthermore, an accumulation of risk factors was accompanied by an increased MRSA prevalence in HCW. PMID:27597843

  15. MRSA Prevalence and Associated Risk Factors among Health-Care Workers in Non-outbreak Situations in the Dutch-German EUREGIO

    PubMed Central

    Sassmannshausen, Ricarda; Deurenberg, Ruud H.; Köck, Robin; Hendrix, Ron; Jurke, Annette; Rossen, John W. A.; Friedrich, Alexander W.

    2016-01-01

    Preventing the spread of methicillin-resistant Staphylococcus aureus (MRSA) in healthcare facilities is a major infection control target. However, only a few studies have assessed the potential role of healthcare workers (HCWs) for MRSA dissemination. To investigate the MRSA prevalence and the risk factors for MRSA colonization among HCWs, nasopharyngeal swabs were taken between June 2010 and January 2011 from 726 employees from nine acute care hospitals with different care levels within the German part of a Dutch-German border region (EUREGIO). The isolated MRSA strains were investigated using spa typing. The overall MRSA prevalence among HCWs in a non-outbreak situation was 4.6% (33 of 726), and was higher in nurses (5.6%, 29 of 514) than in physicians (1.2%, 1 of 83). Possible risk factors associated with MRSA colonization were a known history of MRSA carriage and the presence of acne. Intensive contact with patients may facilitate MRSA transmission between patients and HCWs. Furthermore, an accumulation of risk factors was accompanied by an increased MRSA prevalence in HCW.

  16. MRSA Prevalence and Associated Risk Factors among Health-Care Workers in Non-outbreak Situations in the Dutch-German EUREGIO

    PubMed Central

    Sassmannshausen, Ricarda; Deurenberg, Ruud H.; Köck, Robin; Hendrix, Ron; Jurke, Annette; Rossen, John W. A.; Friedrich, Alexander W.

    2016-01-01

    Preventing the spread of methicillin-resistant Staphylococcus aureus (MRSA) in healthcare facilities is a major infection control target. However, only a few studies have assessed the potential role of healthcare workers (HCWs) for MRSA dissemination. To investigate the MRSA prevalence and the risk factors for MRSA colonization among HCWs, nasopharyngeal swabs were taken between June 2010 and January 2011 from 726 employees from nine acute care hospitals with different care levels within the German part of a Dutch-German border region (EUREGIO). The isolated MRSA strains were investigated using spa typing. The overall MRSA prevalence among HCWs in a non-outbreak situation was 4.6% (33 of 726), and was higher in nurses (5.6%, 29 of 514) than in physicians (1.2%, 1 of 83). Possible risk factors associated with MRSA colonization were a known history of MRSA carriage and the presence of acne. Intensive contact with patients may facilitate MRSA transmission between patients and HCWs. Furthermore, an accumulation of risk factors was accompanied by an increased MRSA prevalence in HCW. PMID:27597843

  17. The Potential Economic Value of a Staphylococcus aureus Vaccine for Neonates

    PubMed Central

    Lee, Bruce Y.; Ufberg, Paul J.; Bailey, Rachel R.; Wiringa, Ann E.; Smith, Kenneth J.; Nowalk, Andrew J.; Higgins, Conor; Wateska, Angela R.; Muder, Robert R.

    2010-01-01

    The continuing morbidity and mortality associated with Staphylococcus aureus (S. aureus) infections, especially methicillin-resistent Staphylococcus aureus (MRSA) infections, have motivated calls to make S. aureus vaccine development a research priority. We developed a decision analytic computer simulation model to determine the potential economic impact of a S. aureus vaccine for neonates. Our results suggest that a S. aureus vaccine for the neonatal population would be strongly cost-effective (and in many situations dominant) over a wide range of vaccine efficacies (down to 10%) for vaccine costs (≤$500), and S. aureus attack rates (≥1%). PMID:20472028

  18. Community-Associated Methicillin-Resistant Staphylococcus aureus Case Studies

    PubMed Central

    Sowash, Madeleine G.; Uhlemann, Anne-Catrin

    2014-01-01

    Over the past decade, the emergence of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has changed the landscape of S. aureus infections around the globe. Initially recognized for its ability to cause disease in young and healthy individuals without healthcare exposures as well as for its distinct genotype and phenotype, this original description no longer fully encompasses the diversity of CA-MRSA as it continues to expand its niche. Using four case studies, we highlight a wide range of the clinical presentations and challenges of CA-MRSA. Based on these cases we further explore the globally polygenetic background of CA-MRSA with a special emphasis on generally less characterized populations. PMID:24085688

  19. Origins of Community Strains of Methicillin-Resistant Staphylococcus aureus

    PubMed Central

    Charlebois, Edwin D.; Perdreau-Remington, Françoise; Kreiswirth, Barry; Bangsberg, David R.; Ciccarone, Daniel; Diep, Binh A.; Ng, Valerie L.; Chansky, Kimberly; Edlin, Brian; Chambers, Henry F.

    2008-01-01

    To characterize methicillin-resistant Staphylococcus aureus (MRSA) strains circulating in the community, we identified predictors of isolating community MRSA and genotyped a sample of MRSA collected from a community-based, high-risk population. Computerized databases of the Community Health Network of San Francisco and the Clinical Microbiology Laboratory were searched electronically for the years 1992–1999 to identify community-onset infections caused by MRSA. Sequential analyses were performed to identify predictors of MRSA strains. The majority (58%) of infections were caused by strains traceable to the hospital or to long-term care facilities. Injection drug use was associated with infections that were not associated with health care settings. Genotypes for 20 of 35 MRSA isolates recovered from injection drug users did not match any of >600 genotypes of clinical isolates. In a nonoutbreak setting, the hospital was the main source of community MRSA; however, the presence of genetically distinct and diverse MRSA strains indicates MRSA strains now also originate from the community. PMID:15206052

  20. Mobile genetic elements of Staphylococcus aureus

    PubMed Central

    Malachowa, Natalia

    2010-01-01

    Bacteria such as Staphylococcus aureus are successful as commensal organisms or pathogens in part because they adapt rapidly to selective pressures imparted by the human host. Mobile genetic elements (MGEs) play a central role in this adaptation process and are a means to transfer genetic information (DNA) among and within bacterial species. Importantly, MGEs encode putative virulence factors and molecules that confer resistance to antibiotics, including the gene that confers resistance to beta-lactam antibiotics in methicillin-resistant S. aureus (MRSA). Inasmuch as MRSA infections are a significant problem worldwide and continue to emerge in epidemic waves, there has been significant effort to improve diagnostic assays and to develop new antimicrobial agents for treatment of disease. Our understanding of S. aureus MGEs and the molecules they encode has played an important role toward these ends and has provided detailed insight into the evolution of antimicrobial resistance mechanisms and virulence. PMID:20668911

  1. Analysis of Transmission of MRSA and ESBL-E among Pigs and Farm Personnel

    PubMed Central

    Stemmer, Franziska; El-Jade, Mohamed; Reif, Marion; Hack, Sylvia; Meilaender, Alina; Montabauer, Gabriele; Fimmers, Rolf; Parcina, Marijo; Hoerauf, Achim; Exner, Martin; Petersen, Brigitte; Bierbaum, Gabriele; Bekeredjian-Ding, Isabelle

    2015-01-01

    Livestock-associated bacteria with resistance to two or more antibiotic drug classes have heightened our awareness for the consequences of antibiotic consumption and spread of resistant bacterial strains in the veterinary field. In this study we assessed the prevalence of concomitant colonization with livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) and enterobacteriaceae expressing extended-spectrum betalactamases (ESBL-E) in farms at the German-Dutch border region. Nasal colonization of pigs with MRSA (113/547 (20.7%)) was less frequent than rectal colonization with ESBL-E (163/540 (30.2%)). On the individual farm level MRSA correlated with ESBL-E recovery. The data further provide information on prevalence at different stages of pig production, including abattoirs, as well as in air samples and humans living and working on the farms. Notably, MRSA was detected in stable air samples of 34 out of 35 pig farms, highlighting air as an important MRSA transmission reservoir. The majority of MRSA isolates, including those from humans, displayed tetracycline resistance and spa types t011 and t034 characteristic for LA-MRSA, demonstrating transmission from pigs to humans. ESBL-E positive air samples were detected on 6 out of 35 farms but no pig-to-human transmission was found. Detection of ESBL-E, e.g. mostly Escherichia coli with CTX-M-type ESBL, was limited to these six farms. Molecular typing revealed transmission of ESBL-E within the pig compartments; however, related strains were also found on unrelated farms. Although our data suggest that acquisition of MRSA and ESBL-E might occur among pigs in the abattoirs, MRSA and ESBL-E were not detected on the carcasses. Altogether, our data define stable air (MRSA), pig compartments (ESBL-E) and abattoir waiting areas (MRSA and ESBL-E) as major hot spots for transmission of MRSA and/or ESBL-E along the pig production chain. PMID:26422606

  2. Analysis of Transmission of MRSA and ESBL-E among Pigs and Farm Personnel.

    PubMed

    Schmithausen, Ricarda Maria; Schulze-Geisthoevel, Sophia Veronika; Stemmer, Franziska; El-Jade, Mohamed; Reif, Marion; Hack, Sylvia; Meilaender, Alina; Montabauer, Gabriele; Fimmers, Rolf; Parcina, Marijo; Hoerauf, Achim; Exner, Martin; Petersen, Brigitte; Bierbaum, Gabriele; Bekeredjian-Ding, Isabelle

    2015-01-01

    Livestock-associated bacteria with resistance to two or more antibiotic drug classes have heightened our awareness for the consequences of antibiotic consumption and spread of resistant bacterial strains in the veterinary field. In this study we assessed the prevalence of concomitant colonization with livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) and enterobacteriaceae expressing extended-spectrum betalactamases (ESBL-E) in farms at the German-Dutch border region. Nasal colonization of pigs with MRSA (113/547 (20.7%)) was less frequent than rectal colonization with ESBL-E (163/540 (30.2%)). On the individual farm level MRSA correlated with ESBL-E recovery. The data further provide information on prevalence at different stages of pig production, including abattoirs, as well as in air samples and humans living and working on the farms. Notably, MRSA was detected in stable air samples of 34 out of 35 pig farms, highlighting air as an important MRSA transmission reservoir. The majority of MRSA isolates, including those from humans, displayed tetracycline resistance and spa types t011 and t034 characteristic for LA-MRSA, demonstrating transmission from pigs to humans. ESBL-E positive air samples were detected on 6 out of 35 farms but no pig-to-human transmission was found. Detection of ESBL-E, e.g. mostly Escherichia coli with CTX-M-type ESBL, was limited to these six farms. Molecular typing revealed transmission of ESBL-E within the pig compartments; however, related strains were also found on unrelated farms. Although our data suggest that acquisition of MRSA and ESBL-E might occur among pigs in the abattoirs, MRSA and ESBL-E were not detected on the carcasses. Altogether, our data define stable air (MRSA), pig compartments (ESBL-E) and abattoir waiting areas (MRSA and ESBL-E) as major hot spots for transmission of MRSA and/or ESBL-E along the pig production chain. PMID:26422606

  3. Genotyping of Methicillin Resistant Staphylococcus aureus from Tertiary Care Hospitals in Coimbatore, South India

    PubMed Central

    Neetu, Toms John Peedikayil; Murugan, Sevanan

    2016-01-01

    Background: Globally, methicillin resistant Staphylococcus aureus (MRSA) is one of the most common pathogens that causes hospital- and community-acquired infections. The use of molecular typing methods is essential for determining the origin of the isolates, their clonal relations, and also epidemiological investigations. Objective: The purpose of this study was to determine the prevalence of antibiotic-resistant MRSA investigate the accessory gene regulator (agr) and staphylococcal cassette chromosome mec (SCCmec) types and perform multilocus sequence typing (MLST). Furthermore, the minimum inhibitory concentration of MRSA isolates was determined for vancomycin and daptomycin. Materials and Methods: Two hundred and fifty-nine MRSA isolates were collected from Tertiary Care Hospitals in Coimbatore. Disk diffusion method was employed to assess the sensitivity of MRSA isolates to selected antibiotics and genetic analysis was performed using SCCmec, agr, and MLST typing by multiplex-polymerase chain reaction strategy. Minimal inhibitory concentration (MIC) was determined using Ezy MIC (vancomycin) and Biomerieux (daptomycin) E-test strip. Results: Of 259 MRSA isolates, 209 (80.7%) were confirmed as methicillin resistant. Antibiotic susceptibility pattern revealed that all the MRSA isolates were 100% sensitive to linezolid, rifampicin, teicoplanin, and vancomycin. MIC results showed that of 209 MRSA isolates, 10 were found to be vancomycin intermediate S. aureus and 100% of the MRSA isolates were daptomycin-susceptible. The agr group I and SCCmec Type III were the major type among MRSA isolates. In addition to these MLST typing revealed the prevalence of sequence type (ST) 239 (SLV of ST8) among the MRSA isolates. Conclusion: This study confirms that ST239 (Brazilian clone) of MRSA is predominant in this region which is responsible for the hospital-acquired MRSA infections. Thus, the study also suggests that vancomycin and daptomycin can still be used as an alternative

  4. Methicillin-resistant Staphylococcus aureus: an overview for manual therapists☆

    PubMed Central

    Green, Bart N.; Johnson, Claire D.; Egan, Jonathon Todd; Rosenthal, Michael; Griffith, Erin A.; Evans, Marion Willard

    2012-01-01

    Objective Methicillin-resistant Staphylococcus aureus (MRSA) is associated with difficult-to-treat infections and high levels of morbidity. Manual practitioners work in environments where MRSA is a common acquired infection. The purpose of this review is to provide a practical overview of MRSA as it applies to the manual therapy professions (eg, physical and occupational therapy, athletic training, chiropractic, osteopathy, massage, sports medicine) and to discuss how to identify and prevent MRSA infections in manual therapy work environments. Methods PubMed and CINAHL were searched from the beginning of their respective indexing years through June 2011 using the search terms MRSA, methicillin-resistant Staphylococcus aureus, and Staphylococcus aureus. Texts and authoritative Web sites were also reviewed. Pertinent articles from the authors' libraries were included if they were not already identified in the literature search. Articles were included if they were applicable to ambulatory health care environments in which manual therapists work or if the content of the article related to the clinical management of MRSA. Results Following information extraction, 95 citations were included in this review, to include 76 peer-reviewed journal articles, 16 government Web sites, and 3 textbooks. Information was organized into 10 clinically relevant categories for presentation. Information was organized into the following clinically relevant categories: microbiology, development of MRSA, risk factors for infection, clinical presentation, diagnostic tests, screening tests, reporting, treatment, prevention for patients and athletes, and prevention for health care workers. Conclusion Methicillin-resistant S aureus is a health risk in the community and to patients and athletes treated by manual therapists. Manual practitioners can play an essential role in recognizing MRSA infections and helping to control its transmission in the health care environment and the community

  5. Strategies for controlling methicillin-resistant Staphylococcus aureus in hospitals.

    PubMed

    Boyce, J M

    1995-07-01

    In areas where the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) is very low, aggressive strategies, which appear to have been effective, such as those used in the Netherlands and western Australia, may be feasible. In hospitals where MRSA is epidemic or highly endemic, less rigorous strategies are appropriate. However, which isolation techniques and barrier precautions are optimal is controversial. In addition, there is no consensus regarding the epidemiological importance of environmental contamination. Rapid detection of MRSA, prompt implementation of barrier precautions and prospective surveillance are essential components of a successful control programme. Eradicating nasal carriage of MRSA among patients and personnel can be useful during epidemics, but the cost-effectiveness of using this approach in hospitals where the prevalence of MRSA is low is unknown. Additional studies of this issue need to include surveillance for mupirocin-resistant strains.

  6. Molecular and Clinical Characteristics of Hospital and Community Onset Methicillin-Resistant Staphylococcus aureus Strains Associated with Bloodstream Infections

    PubMed Central

    Hines, Lisa; van Balen, Joany; Mediavilla, José R.; Pan, Xueliang; Hoet, Armando E.; Kreiswirth, Barry N.; Pancholi, Preeti; Stevenson, Kurt B.

    2015-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infections (BSI) are classified epidemiologically as health care-associated hospital onset (HAHO)-, health care-associated community onset (HACO)-, or community-associated (CA)-MRSA. Clinical and molecular differences between HAHO- and HACO-MRSA BSI are not well known. Thus, we evaluated clinical and molecular characteristics of MRSA BSI to determine if distinct features are associated with HAHO- or HACO-MRSA strains. Molecular genotyping and medical record reviews were conducted on 282 MRSA BSI isolates from January 2007 to December 2009. MRSA classifications were 38% HAHO-, 54% HACO-, and 8% CA-MRSA. Comparing patients with HAHO-MRSA to those with HACO-MRSA, HAHO-MRSA patients had significantly higher rates of malignancy, surgery, recent invasive devices, and mortality and longer hospital stays. Patients with HACO-MRSA were more likely to have a history of renal failure, hemodialysis, residence in a long-term-care facility, long-term invasive devices, and higher rate of MRSA relapse. Distinct MRSA molecular strain differences also were seen between HAHO-MRSA (60% staphylococcal cassette chromosome mec type II [SCCmec II], 30% SCCmec III, and 9% SCCmec IV) and HACO-MRSA (47% SCCmec II, 35% SCCmec III, and 16% SCCmec IV) (P < 0.001). In summary, our study reveals significant clinical and molecular differences between patients with HAHO- and HACO-MRSA BSI. In order to decrease rates of MRSA infection, preventive efforts need to be directed toward patients in the community with health care-associated risk factors in addition to inpatient infection control. PMID:25740776

  7. Prevalence and Characterization of Methicillin-Resistant Staphylococcus aureus Isolates from Retail Meat and Humans in Georgia

    PubMed Central

    Davis, Johnnie A.; Barrett, John B.

    2013-01-01

    There is increasing interest in the presence of Staphylococcus aureus, specifically methicillin-resistant S. aureus (MRSA), on retail meat products. In this study, staphylococci were isolated from retail pork and retail beef in Georgia, and MRSA from the products was compared to human MRSA from the same geographic area using broth microdilution antimicrobial susceptibility testing, multilocus sequence typing (MLST), spa typing, SCCmec typing, and pulsed-field gel electrophoresis (PFGE). S. aureus was isolated from 45% (45/100) of pork products and 63% (63/100) of beef products; mecA was detected in S. aureus from both pork (3/100; 3%) and beef (4/100; 4%). Fifty percent (50/100) of human S. aureus also contained mecA. Multidrug resistance was detected among MRSA from all sources. All MRSA (n = 57) was SCCmec type IV, and nine different spa types were present among the isolates (t002, t008, t012, t024, t179, t337, t548, t681, and t1062). Four sequence types (ST5, ST8, ST9, and ST30) were detected using MLST; the majority of MRSA isolates belonged to ST8, followed by ST5. One retail beef MRSA isolate belonged to ST8, while the remaining three were ST5. In retail pork MRSA, ST5, ST9, and ST30 were observed. The majority of human MRSA isolates belonged to ST8. Thirty-seven MRSA isolates, one of which was a retail beef MRSA isolate, were pvl+. Using PFGE, MLST, and spa typing, three retail beef MRSA isolates were found to be identical in PFGE pattern, ST, and spa type to two human clonal MRSA isolates (USA100 and USA300). One additional retail beef MRSA isolate had a PFGE pattern similar to that of a human MRSA isolate, whereas none of the retail pork MRSA isolates had PFGE patterns similar to those of human MRSA isolates. These data suggest that the retail beef samples were contaminated by a human source, possibly during processing of the meat, and may present a source of MRSA for consumers and others who handle raw meat. PMID:23363837

  8. Nasal Staphylococcus aureus and Methicillin-Resistant S. aureus Carriage among Janitors Working in Hospitals in Northern Taiwan

    PubMed Central

    Huang, Yhu-Chering

    2015-01-01

    Background Staphylococcus aureus is an important cause of infection, and brings additional concern with methicillin resistance. In addition, nasal methicillin-resistant Staphylococcus aureus (MRSA) colonization rates among health care workers are higher than that for general population. To determine the prevalence rate and risk factors for the colonization of S. aureus, including MRSA, among janitors working in hospitals in northern Taiwan, we conducted this study. Methods Between June and August, 2014, a total of 186 janitors, 111 working in hospitals and 75 working in non-medical institutions, were recruited. Specimens were obtained from the nares of the subjects for the detection of S. aureus, with a questionnaire completed for each subject. All the S. aureus isolates, including MRSA and methicillin-susceptible S. aureus (MSSA), were further molecularly characterized. Results The nasal carriage rate of S. aureus was 15.3% for hospital janitors and 13.3% for non-medical janitors. The carriage rate of MRSA was 3.6% for hospital janitors and 1.3% for non-medical janitors. No statistically significant difference was found in the nasal carriage rate of S. aureus (p = 0.707) and MRSA (p = 0.65) between hospital janitors and non-medical janitors. Hospital janitors working in hospital more than 6 years and cleaning microbiologic laboratories were significantly associated with nasal S. aureus colonization. All 5 MRSA isolates carried either staphylococcal cassette chromosome type IV or V and three of them belonged to sequence type (ST) 59, the community clone prevailing in Taiwan. Of the 22 MSSA isolates, six pulsotypes were identified, with one major type for 14 isolates (shared by five STs) and another type for 4 isolates (all belonged to ST 188). Conclusion Exposure to the hospital environment may not increase the nasal carriage rate of S. aureus, including MRSA, among janitors in hospitals in Taiwan. However, for janitors in the hospital setting, working for more

  9. Determination of the antibiofilm, antiadhesive, and anti-MRSA activities of seven Salvia species

    PubMed Central

    Al-Bakri, Amal G.; Othman, Ghadeer; Afifi, Fatma U.

    2010-01-01

    Background: Several Salvia species are indigenous to Jordan and are widely used as beverages and spices and for their medicinal properties. The objective of the study was to establish the antimicrobial activities, including the antiadhesive and antibiofilm effects of seven different Salvia species. Materials and Methods: Methods used for planktonic culture included agar diffusion, broth microdilution, and minimal biocidal concentration determination while viable count was used for the determination of the antibiofilm and antiadhesion activities. Overnight cultures of reference strains of Candida albicans, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus and clinical strains of methicillin-resistant S. aureus (MRSA) were used as test microorganisms. Results: An antimicrobial activity toward planktonic cultures demonstrated a significant bacteriocidal activity (≥4 log cycle reduction) for the S. triloba extract against S. aureus including MRSA. Its volatile oil exhibited an antimicrobial activity covering all tested microorganisms with the exception of P. aeruginosa. S. triloba extract and volatile oil were successful in preventing and controlling the biofilm, demonstrating antiadhesion and antibiofilm activities, respectively. Conclusion: These reported activities for S. triloba extract and volatile oil allows their listing as potential antibiofilm and anti-MRSA natural agents. This might suggest their use as an antiseptic in the prophylaxis and treatment of S. aureus-associated skin infections. The antimicrobial activity of the other tested Salvia species was negligible. PMID:21120026

  10. Cost-effectiveness of universal MRSA screening on admission to surgery.

    PubMed

    Murthy, A; De Angelis, G; Pittet, D; Schrenzel, J; Uckay, I; Harbarth, S

    2010-12-01

    Policy-makers have recommended universal screening to reduce nosocomial methicillin-resistant Staphylococcus aureus (MRSA) infection. Risk profiling of MRSA carriers and rapid PCR tests are now available, yet cost-effectiveness data are limited. The present study assessed the cost-effectiveness of universal PCR screening on admission to surgery. A decision analysis model from the hospital perspective compared costs and the probability of any MRSA infection across three strategies: (i) PCR screening; (ii) screening for risk factors (prior hospitalization or antibiotic use) combined with pre-emptive isolation and contact precautions pending chromogenic agar results; and (iii) no screening. Clinical data were taken from studies at a Swiss teaching hospital as well as from published literature. Costs were derived from hospital accounting systems. Compared to no screening, the PCR strategy resulted in higher costs (CHF 10503 vs. 10358) but a lower infection probability (0.0041 vs. 0.0088), producing a base-case incremental cost-effectiveness ratio of CHF 30784 per MRSA infection avoided. The risk factor strategy was more costly yet less effective than PCR, although, after varying epidemiologic inputs, the costs and effects of both screening strategies were similar. Sensitivity analyses suggested that on-admission prevalence of MRSA carriage predicts cost-effectiveness, alongside the probability of cross-transmission, and the costs of MRSA infection, screening and contact precautions. Although reducing the risk of MRSA infection, universal PCR screening is not strongly cost-effective at our centre. However, local epidemiology plays a critical role. Settings with a higher prevalence of MRSA colonization may find universal screening cost-effective and, in some cases, cost-saving.

  11. Methicillin-resistant Staphylococcus aureus antibiotic resistance and virulence.

    PubMed

    Xia, Jufeng; Gao, Jianjun; Kokudo, Norihiro; Hasegawa, Kiyoshi; Tang, Wei

    2013-06-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most critical causes of healthcare-related or community-related infections. Resistance to most β-lactam antibiotics makes MRSA a big threat to clinical treatment. Utilization of low efficiency antibiotics such as vancomycin and teicoplanin makes new choices for therapies. Recently, much researchhas shed light on relevance between genetic mutations of MRSA and clinical characteristics such as antibiotic resistance, and virulence. These findings could contribute to development of novel antibiotics and vaccines.

  12. Haemodialysis nurses knowledge about methicillin-resistant Staphylococcus aureus.

    PubMed

    Lindberg, Maria; Lindberg, Magnus

    2012-06-01

    Healthcare workers may lack knowledge about antibiotic-resistant bacteria and thereby increase the spread of such organisms. The aim of the present study was to describe the relationship between self-rated knowledge and actual knowledge about methicillin-resistant Staphylococcus aureus (MRSA) among 326 Swedish haemodialysis nurses. Data were collected through a postal questionnaire. The findings suggest that ongoing education about MRSA should be provided to haemodialysis nurses, but also that standardised evaluation of adequate knowledge, skills and competencies' regarding safe practices is warranted. Future research should focus on effective mechanisms to ensure that haemodialysis nurses provide safe MRSA care. PMID:22085397

  13. A Novel Core Genome-Encoded Superantigen Contributes to Lethality of Community-Associated MRSA Necrotizing Pneumonia

    PubMed Central

    Wilson, Gillian J.; Seo, Keun Seok; Cartwright, Robyn A.; Connelley, Timothy; Chuang-Smith, Olivia N.; Merriman, Joseph A.; Guinane, Caitriona M.; Park, Joo Youn; Bohach, Gregory A.; Schlievert, Patrick M.; Morrison, W. Ivan; Fitzgerald, J. Ross

    2011-01-01

    Bacterial superantigens (SAg) stimulate T-cell hyper-activation resulting in immune modulation and severe systemic illnesses such as Staphylococcus aureus toxic shock syndrome. However, all known S. aureus SAgs are encoded by mobile genetic elements and are made by only a proportion of strains. Here, we report the discovery of a novel SAg staphylococcal enterotoxin-like toxin X (SElX) encoded in the core genome of 95% of phylogenetically diverse S. aureus strains from human and animal infections, including the epidemic community-associated methicillin-resistant S. aureus (CA-MRSA) USA300 clone. SElX has a unique predicted structure characterized by a truncated SAg B-domain, but exhibits the characteristic biological activities of a SAg including Vβ-specific T-cell mitogenicity, pyrogenicity and endotoxin enhancement. In addition, SElX is expressed by clinical isolates in vitro, and during human, bovine, and ovine infections, consistent with a broad role in S. aureus infections of multiple host species. Phylogenetic analysis suggests that the selx gene was acquired horizontally by a progenitor of the S. aureus species, followed by allelic diversification by point mutation and assortative recombination resulting in at least 17 different alleles among the major pathogenic clones. Of note, SElX variants made by human- or ruminant-specific S. aureus clones demonstrated overlapping but distinct Vβ activation profiles for human and bovine lymphocytes, indicating functional diversification of SElX in different host species. Importantly, SElX made by CA-MRSA USA300 contributed to lethality in a rabbit model of necrotizing pneumonia revealing a novel virulence determinant of CA-MRSA disease pathogenesis. Taken together, we report the discovery and characterization of a unique core genome-encoded superantigen, providing new insights into the evolution of pathogenic S. aureus and the molecular basis for severe infections caused by the CA-MRSA USA300 epidemic clone. PMID

  14. Influenza infection suppresses NADPH oxidase-dependent phagocytic bacterial clearance and enhances susceptibility to secondary MRSA infection

    PubMed Central

    Sun, Keer; Metzger, Dennis W.

    2014-01-01

    Methicillin-resistant S. aureus (MRSA) has emerged as a leading contributor to mortality during recent influenza pandemics. The mechanism for this influenza-induced susceptibility to secondary S. aureus infection is poorly understood. Here we show that innate antibacterial immunity was significantly suppressed during the recovery stage of influenza infection, despite the fact that MRSA super-infection had no significant effect on viral burdens. Compared to mice infected with bacteria alone, post-influenza MRSA infected mice exhibited impaired bacterial clearance, which was not due to defective phagocyte recruitment, but rather coincided with reduced intracellular reactive oxygen species (ROS) levels in alveolar macrophages and neutrophils. NADPH oxidase is responsible for ROS production during phagocytic bacterial killing, a process also known as oxidative burst. We found that gp91phox-containing NADPH oxidase activity in macrophages and neutrophils was essential for optimal bacterial clearance during respiratory MRSA infections. In contrast to WT animals, gp91phox−/− mice exhibited similar defects in MRSA clearance before and after influenza infection. Using gp91phox+/− mosaic mice, we further demonstrate that influenza infection inhibits a cell-intrinsic contribution of NADPH oxidase to phagocyte bactericidal activity. Together, our results establish that influenza infection suppresses NADPH oxidase-dependent bacterial clearance and leads to susceptibility to secondary MRSA infection. PMID:24563256

  15. Minimum structural requirements for cell membrane leakage-mediated anti-MRSA activity of macrocyclic bis(bibenzyl)s.

    PubMed

    Fujii, Kana; Morita, Daichi; Onoda, Kenji; Kuroda, Teruo; Miyachi, Hiroyuki

    2016-05-01

    Macrocyclic bis(bibenzyl)-type phenolic natural products, found exclusively in bryophytes, exhibit potent antibacterial activity towards methicillin-resistant Staphylococcus aureus (anti-MRSA activity). Here, in order to identify the minimum essential structure for cell membrane leakage-mediated anti-MRSA activity of these compounds, we synthesized acyclic fragment structures and evaluated their anti-MRSA activity. The activities of all of the acyclic fragments tested exhibited similar characteristics to those of the macrocycles, i.e., anti-MRSA bactericidal activity, an enhancing effect on influx and efflux of ethidium bromide (EtBr: fluorescent DNA-binder) in Staphylococcus aureus cells, and bactericidal activity towards a Staphylococcus aureus strain resistant to 2-phenoxyphenol (4). The latter result suggests that they have a different mechanism of action from 4, which is a FabI inhibitor previously proposed to be the minimum active fragment of riccardin-type macrocycles. Thus, cyclic structure is not a necessary condition for cell membrane leakage-mediated anti-MRSA activity of macrocyclic bis(bibenzyl)s. PMID:26995530

  16. First report of methicillin-resistant Staphylococcus aureus from cage-cultured tilapia (Oreochromis niloticus).

    PubMed

    Atyah, M A S; Zamri-Saad, M; Siti-Zahrah, A

    2010-08-26

    Swabs from the brain, eyes and kidneys of tilapia from 11 farms were collected for a period of 2 years. They were grown on blood agar before cultures of suspected Staphylococcus aureus were subjected to ABI STAPH Detection Kit and PCR for identification. They were then grown on oxacillin resistance screening agar base (ORSAB) and subjected to PCR using the MRSA 17 kb forward and reverse primers to identify the methicillin-resistant S. aureus (MRSA). A total of 559 isolates of Staphylococcus spp. were obtained, from which 198 (35%) isolates were identified as S. aureus. Of the 198 S. aureus isolated from tilapias, 98 (50%) were identified as methicillin-resistant S. aureus (MRSA). Since global spread of multi-drug-resistant bacteria has increased in the past decade, this new finding in fish should be of concern. PMID:20189324

  17. Staphylococcus aureus Colonization Among Household Contacts of Patients With Skin Infections: Risk Factors, Strain Discordance, and Complex Ecology

    PubMed Central

    Miller, Loren G.; Eells, Samantha J.; Taylor, Alexis R.; David, Michael Z.; Ortiz, Nancy; Zychowski, Diana; Kumar, Neha; Cruz, Denise; Boyle-Vavra, Susan; Daum, Robert S.

    2012-01-01

    Background. The USA300 methicillin resistant Staphylococcus aureus (MRSA) genetic background has rapidly emerged as the predominant cause of community-associated S. aureus infections in the U.S. However, epidemiologic characteristics of S. aureus household transmission are poorly understood. Methods. We performed a cross-sectional study of adults and children with S. aureus skin infections and their household contacts in Los Angeles and Chicago. Subjects were surveyed for S. aureus colonization of the nares, oropharynx, and inguinal region and risk factors for S. aureus disease. All isolates underwent genetic typing. Results. We enrolled 1162 persons (350 index patients and 812 household members). The most common infection isolate characteristic was ST8/SCCmec IV, PVL+ MRSA (USA300) (53%). S. aureus colonized 40% (137/350) of index patients and 50% (405/812) of household contacts. A nares-only survey would have missed 48% of S. aureus and 51% of MRSA colonized persons. Sixty-five percent of households had >1 S. aureus genetic background identified and 26% of MRSA isolates in household contacts were discordant with the index patients' infecting MRSA strain type. Factors independently associated (P < .05) with the index strain type colonizing household contacts were recent skin infection, recent cephalexin use, and USA300 genetic background. Conclusions. In our study population, USA300 MRSA appeared more transmissible among household members compared with other S. aureus genetic backgrounds. Strain distribution was complex; >1 S. aureus genetic background was present in many households. S. aureus decolonization strategies may need to address extra-nasal colonization and the consequences of eradicating S. aureus genetic backgrounds infrequently associated with infection. PMID:22474221

  18. Bovine mastitis Staphylococcus aureus: antibiotic susceptibility profile, resistance genes and molecular typing of methicillin-resistant and methicillin-sensitive strains in China.

    PubMed

    Wang, Dengfeng; Wang, Zhicai; Yan, Zuoting; Wu, Jianyong; Ali, Tariq; Li, Jianjun; Lv, Yanli; Han, Bo

    2015-04-01

    The emergence of methicillin-resistant Staphylococcus aureus (MRSA) infection in dairy animals is of great concern for livestock and public health. The aim of present study was to detect new trends of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA) towards antibiotic susceptibility, resistance genes and molecular typing by methods of disc diffusion, multiplex PCR assay and multilocus sequence typing (MLST). A total of 219 S. aureus strains were isolated from bovine mastitis cases from six provinces of China, including 34 MRSA strains. The results revealed that more than 70% isolated strains showed resistance to various antibiotics, and multiple-drugs resistance to more than five categories of antibiotics was found more common. The ermC was the most prevalent resistance gene, followed by other genes; however, ermA was the least frequently detected gene. Twenty-eight mecA-negative MRSA and six mecA-positive MRSA strains were detected, and in which three strains were ST97-MRSA-IV, others were ST965-MRSA-IV, ST6-MRSA-IV and ST9-MRSA-SCCmec-NT. The mecA-negative MRSA strains were found resistant to most of the antibiotics, and harbored aac(6')/aph(2''), aph(3')-III and tetM genes higher than MSSA strains. The resistance to most of the antibiotics was significantly higher in MRSA than in MSSA strains. The MLST profiles showed that these strains mainly belonged to CC5, CC398, CC121 and CC50 lineage, especially within ST97 and ST398, while some novel sequence types (ST2154, ST2165 and ST2166) were identified and deposited in the MLST database. This indicates that the resistance of S. aureus is becoming more complicated by changes in multi-drug resistance mechanism and appearance of mecA-negative MRSA isolates, and importantly, MRSA-IV strains in different MLST types are emerging.

  19. Discovery of wall teichoic acid inhibitors as potential anti-MRSA β-lactam combination agents.

    PubMed

    Wang, Hao; Gill, Charles J; Lee, Sang H; Mann, Paul; Zuck, Paul; Meredith, Timothy C; Murgolo, Nicholas; She, Xinwei; Kales, Susan; Liang, Lianzhu; Liu, Jenny; Wu, Jin; Santa Maria, John; Su, Jing; Pan, Jianping; Hailey, Judy; Mcguinness, Debra; Tan, Christopher M; Flattery, Amy; Walker, Suzanne; Black, Todd; Roemer, Terry

    2013-02-21

    Innovative strategies are needed to combat drug resistance associated with methicillin-resistant Staphylococcus aureus (MRSA). Here, we investigate the potential of wall teichoic acid (WTA) biosynthesis inhibitors as combination agents to restore β-lactam efficacy against MRSA. Performing a whole-cell pathway-based screen, we identified a series of WTA inhibitors (WTAIs) targeting the WTA transporter protein, TarG. Whole-genome sequencing of WTAI-resistant isolates across two methicillin-resistant Staphylococci spp. revealed TarG as their common target, as well as a broad assortment of drug-resistant bypass mutants mapping to earlier steps of WTA biosynthesis. Extensive in vitro microbiological analysis and animal infection studies provide strong genetic and pharmacological evidence of the potential effectiveness of WTAIs as anti-MRSA β-lactam combination agents. This work also highlights the emerging role of whole-genome sequencing in antibiotic mode-of-action and resistance studies.

  20. Longitudinal study on the colonisation and transmission of methicillin-resistant Staphylococcus aureus in pig farms.

    PubMed

    Bangerter, Patrick Daniel; Sidler, Xaver; Perreten, Vincent; Overesch, Gudrun

    2016-02-01

    Knowledge about the dynamics of methicillin-resistant Staphylococcus aureus (MRSA) in pigs lacks detail at the level of individual animal. The aim of our study was therefore to determine the colonisation status of MRSA in individual pigs from birth to slaughter in order to gain a better understanding of substantial factors involved in transmission. Two farrow-to-finish and two grow-to-finish herds were included in the study. A total of 1728 nasal swabs from 390 pigs and 592 environmental wipes were collected at 11 different time points. Intermittent colonisation throughout the entire production cycle was conspicuous in the tracking of MRSA in individual pigs. Almost all pigs from a MRSA-positive herd changed MRSA status several times, which implies that pigs are transiently rather than permanently colonised. We highly recommend the definition of MRSA status at herd level rather that at the level of the individual pig when considering prevention measures against MRSA. Therefore, to avoid the further spread of MRSA in countries with moderate prevalence, such as in Switzerland, defining farms as MRSA positive or MRSA negative and allowing the trade of pigs only within herds of the same status seems feasible. This will also be important for combating the further dissemination of livestock-associated (LA)-MRSA into healthcare facilities and the community via humans who have close contact with animals.

  1. Methicillin-resistant Staphylococcus aureus in Canada: a historical perspective and lessons learned.

    PubMed

    Cimolai, Nevio

    2010-02-01

    The history of methicillin-resistant Staphylococcus aureus (MRSA) in Canada has many similarities to MRSA evolution worldwide, but especially to that in the United States and United Kingdom. Reports of MRSA occurred as early as 1964, and community isolates were cited in the 1970s. Nosocomial outbreaks were becoming common by 1978 and flourished gradually thereafter. Endemic institutional MRSA became predominant in the 1990s, threatening large teaching hospitals in particular. In the last decade, both hospital-acquired and community-acquired MRSA have created major medical problems in Canada. More recently, an epidemic of Canadian community-acquired MRSA-10, has led to heightened public health concerns. Canadian contributions to MRSA science are numerous, with organized surveillance continuing to mature across the nation. A typing system for epidemic clones is now available and is being judiciously applied. Estimated costs for MRSA surveillance, treatment, and control are extraordinary, paralleling the dramatic rise in the number of MRSA isolations. Whereas surveillance continues to form an essential aspect of MRSA management, control, eradication, and overall diminution, MRSA reservoirs deserve much greater attention. Such efforts, however, must be as widely publicized in the community and in patient homes as they are in medical institutions responsible for both acute and long-term care.

  2. Comparative virulence studies and transcriptome analysis of Staphylococcus aureus strains isolated from animals

    PubMed Central

    Iqbal, Zahid; Seleem, Mohamed N.; Hussain, Hafiz Iftikhar; Huang, Lingli; Hao, Haihong; Yuan, Zonghui

    2016-01-01

    Several studies have been conducted to check the prevalence of methicillin-resistant strains of Staphylococcus aureus (MRSA) in animals and animal-derived food products but limited data are available regarding their virulence and associated gene expression profile. In the present study, antibiotic resistance and virulence of MRSA and methicillin-sensitive S. aureus animal isolates were determined in vitro by agar dilution, biofilm formation, adhesion, invasion and intracellular survivability assays. In addition, the pathogenicity of these isolates was examined in a murine model of S. aureus sepsis. MRSA1679a, a strain isolated from chicken, was observed to be highly virulent, in cell culture and in mouse model, and exhibited extensive resistant profile. Comparative gene expression profile of MRSA1679a and the reference human MRSA strain (ATCC 29213) was performed using Illumina-based transcriptome and RT-qPCR analyses. Several virulence elements including 22 toxin genes were detected in MRSA animal-isolate. In addition, we observed enhanced expression of crucial virulence regulators, such as sarA and KdpDE in MRSA animal-isolate compared to the human isolate. Collectively, gene expression profile including several virulence and drug-resistance factors confirmed the unique and highly virulent determinants of the MRSA strain of poultry origin which warrants further attention due to significant threat to public health. PMID:27739497

  3. Antimicrobial activities of bacteriocins E50-52 and B602 against MRSA and other nosocomial infections

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our objective was to determine the antimicrobial activities of previously published bacteriocins E50-52 and B602 against methicillin resistant Staphylococcus aureus (MRSA) and other prominent nosocomial bacterial infections. methods: Several Russian hospitals were enlisted into the study from 2003 ...

  4. Antimicrobial (Drug) Resistance: Methicillin-Resistant Staphylococcus aureus (MRSA)

    MedlinePlus

    ... NIAID invests in basic research to understand the biology of microbes, their behavior, and how drug resistance ... Nucleotide Polymorphism Phylogenetics & Ontology Proteomics & Protein Analysis Systems Biology Data Portals Software Applications BCBB Mobyle Interface Designer ( ...

  5. Aryl-Alkyl-Lysines: Agents That Kill Planktonic Cells, Persister Cells, Biofilms of MRSA and Protect Mice from Skin-Infection

    PubMed Central

    Ghosh, Chandradhish; Manjunath, Goutham B.; Konai, Mohini M.; Uppu, Divakara S. S. M.; Hoque, Jiaul; Paramanandham, Krishnamoorthy; Shome, Bibek R.; Haldar, Jayanta

    2015-01-01

    Development of synthetic strategies to combat Staphylococcal infections, especially those caused by methicillin resistant Staphyloccus aureus (MRSA), needs immediate attention. In this manuscript we report the ability of aryl-alkyl-lysines, simple membrane active small molecules, to treat infections caused by planktonic cells, persister cells and biofilms of MRSA. A representative compound