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Sample records for aureus mrsa col

  1. MRSA

    MedlinePlus

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness 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_ ...

  2. 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

  3. 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. Hospital- ...

  4. Laboratory Maintenance of Methicillin-Resistant Staphylococcus aureus (MRSA)

    PubMed Central

    Vitko, Nicholas P.; Richardson, Anthony R.

    2014-01-01

    Staphylococcus aureus is an important bacterial pathogen in the hospital and community settings, especially Staphylococcus aureus clones that exhibit methicillin-resistance (MRSA). Many strains of S. aureus are utilized in the laboratory, underscoring the genetic differences inherent in clinical isolates. S. aureus grows quickly at 37°C with aeration in rich media (e.g. BHI) and exhibits a preference for glycolytic carbon sources. Furthermore, S. aureus has a gold pigmentation, exhibits β-hemolysis, and is catalase and coagulase positive. The four basic laboratory protocols presented in this unit describe how to culture S. aureus on liquid and solid media, how to identify S. aureus strains as methicillin resistant, and how to generate a freezer stock of S. aureus for long-term storage. PMID:23408135

  5. Methicillin-Resistant Staphylococcus aureus (MRSA) Infections in the Department of Defense (DOD): Annual Summary 2013

    DTIC Science & Technology

    2015-01-06

    Methicillin-Resistant Staphylococcus aureus (MRSA) Infections in the Department of Defense (DOD): Annual Summary 2013 NMCPHC-EDC-TR-44...December 2014 EpiData Center Department Abstract Methicillin-resistant Staphylococcus aureus (MRSA) infections are a national concern for public...Navy (DON) beneficiary populations. This report provides a summary of Methicillin-resistant Staphylococcus aureus (MRSA) incidence and prevalence

  6. 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

  7. 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

  8. 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.

  9. Methicillin-resistant Staphylococcus aureus (mrsa) in a Malaysian hospital.

    PubMed

    Cheong, I; Tan, S C; Wong, Y H; Zainudin, B M; Rahman, M Z

    1994-03-01

    Between August 1990 to November 1991, 905 of 2583 (35.4%) isolates of Staphylococcus aureus were found to be methicillin-resistant in a general hospital in Malaysia. A detailed study of 539 of these isolates showed a high prevalence of methicillin resistant Staphylococcus aureus (MRSA) in the surgical/orthopaedic wards, paediatric wards and the special care unit. The yield of MRSA was highest from wounds/ulcers/skin swabs accounting for 64.2 per cent followed by 6.9 per cent in blood cultures. Vancomycin remains the drug of choice with no resistance detected. The resistance to ciprofloxacin was 6.7 per cent, rifampicin 4.5 per cent and fusidic acid 2.0 per cent. Most isolates were resistant to aminoglycosides. In view of the high prevalence of MRSA in this hospital, the authorities must introduce more effective measures to control its spread as a nosocomial pathogen. Otherwise it may seriously disrupt the efficient delivery of health care services in the country.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. Current methodologies on genotyping for nosocomial pathogen methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Miao, Jian; Chen, Lequn; Wang, Jingwen; Wang, Wenxin; Chen, Dingqiang; Li, Lin; Li, Bing; Deng, Yang; Xu, Zhenbo

    2017-03-08

    Methicillin-resistant Staphylococcus aureus (MRSA) is a common pathogen in hospitals and the community. As the rapid spread and wide distribution of antimicrobial resistance (such as MRSA), treatment for infectious diseases caused by microorganisms has become a vital threat. Thus, early identification and genotyping are essential for further therapeutic treatment and the control of rapid expansion of MRSA. In combination with applications and data feedbacks, this review focused on the currently available molecular-based assays on their utility and performance for rapid typing of MRSA, especially on effective molecular-based methods. Besides, a common mobile element SCCmec and prevalence of HA-MRSA, LA-MRSA and CA-MRSA were introduced in this review in order to provide a more complete profile of MRSA.

  16. Proposal for common Nordic epidemiological terms and definitions for methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Skov, Robert; Gudlaugsson, Olafur; Hardardottir, Hjordis; Harthug, Stig; Jakobsen, Trond; Kolmos, Hans Jørn; Olsson-Liljequist, Barbro; Peltonen, Reijo; Tveten, Yngvar; Vuopio-Varkila, Jaana; Ahrén, Christina

    2008-01-01

    The recent increase in the incidence of methicillin-resistant Staphylococcus aureus in all the Nordic countries prompted the Scandinavian Society for Antimicrobial Chemotherapy (SSAC) to create the 'SSAC Working Party on MRSA' with the objective to identify methods to keep the invasive MRSA infections in the Nordic countries below 1%. The lack of common definitions was recognized as a major obstacle for a joint Nordic effort to combat MRSA. The aim of this publication is to present proposals for epidemiological definitions of individual cases, for how to report MRSA frequency per country, and for communication of MRSA strain characteristics between the countries.

  17. 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

  18. Nasal Methicillin-Resistant Staphylococcus aureus (MRSA) PCR Testing Reduces the Duration of MRSA-Targeted Therapy in Patients with Suspected MRSA Pneumonia.

    PubMed

    Baby, Nidhu; Faust, Andrew C; Smith, Terri; Sheperd, Lyndsay A; Knoll, Laura; Goodman, Edward L

    2017-04-01

    The objective of this study was to evaluate the impact of pharmacist-ordered methicillin-resistant Staphylococcus aureus (MRSA) PCR testing on the duration of empirical MRSA-targeted antibiotic therapy in patients with suspected pneumonia. This is a retrospective analysis of patients who received vancomycin or linezolid for suspected pneumonia before and after the implementation of a pharmacist-driven protocol for nasal MRSA PCR testing. Patients were included if they were adults of >18 years of age and initiated on vancomycin or linezolid for suspected MRSA pneumonia. The primary endpoint was the duration of vancomycin or linezolid therapy. After screening 368 patients, 57 patients met inclusion criteria (27 pre-PCR and 30 post-PCR). Baseline characteristics were similar between the two groups, with the majority of patients classified as having health care-associated pneumonia (68.4%). The use of the nasal MRSA PCR test reduced the mean duration of MRSA-targeted therapy by 46.6 h (74.0 ± 48.9 h versus 27.4 ± 18.7 h; 95% confidence interval [CI], 27.3 to 65.8 h; P < 0.0001). Fewer patients in the post-PCR group required vancomycin serum levels and dose adjustment (48.1% versus 16.7%; P = 0.02). There were no significant differences between the pre- and post-PCR groups regarding days to clinical improvement (1.78 ± 2.52 versus 2.27 ± 3.34; P = 0.54), length of hospital stay (11.04 ± 9.5 versus 8.2 ± 7.8; P = 0.22), or hospital mortality (14.8% versus 6.7%; P = 0.41). The use of nasal MRSA PCR testing in patients with suspected MRSA pneumonia reduced the duration of empirical MRSA-targeted therapy by approximately 2 days without increasing adverse clinical outcomes.

  19. In vitro susceptibility of Staphylococcus aureus including MRSA to four disinfectants.

    PubMed

    Suzuki, J; Komatsuzawa, H; Kozai, K; Nagasaka, N

    1997-01-01

    The spread of nosocomial infections caused by pathogenic organisms such as methicillin-resistant S. aureus (MRSA) has prompted the dental community to focus more attention on certain control strategies. In the present study, we tested the abilities of the four skin disinfectants (povidone iodine, benzalkonium chloride, chlorhexidine gluconate, and ethanol) to prevent horizontal transmission of MRSA in the dental office. The bactericidal activities of the disinfectants were evaluated by the decrement over time of viable cell numbers of four clinical isolated strains of S. aureus: two MRSA strains and two methicillin-sensitive S. aureus (MSSA) strains. The most effective disinfectant was 70 percent ethanol, which eradicated both MRSA and MSSA in less than three minutes. The 0.1 percent chlorhexidine gluconate proved the least effective of four disinfectants. More than 10(2) bacteria survived despite exposure to it for thirty minutes.

  20. 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

  1. 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

  2. The Plasmin-Sensitive Protein Pls in Methicillin-Resistant Staphylococcus aureus (MRSA) Is a Glycoprotein

    PubMed Central

    Pohlentz, Gottfried; Xia, Guoqing; Hussain, Muzaffar; Foster, Simon; Peters, Georg

    2017-01-01

    Most bacterial glycoproteins identified to date are virulence factors of pathogenic bacteria, i.e. adhesins and invasins. However, the impact of protein glycosylation on the major human pathogen Staphylococcus aureus remains incompletely understood. To study protein glycosylation in staphylococci, we analyzed lysostaphin lysates of methicillin-resistant Staphylococcus aureus (MRSA) strains by SDS-PAGE and subsequent periodic acid-Schiff’s staining. We detected four (>300, ∼250, ∼165, and ∼120 kDa) and two (>300 and ∼175 kDa) glycosylated surface proteins with strain COL and strain 1061, respectively. The ∼250, ∼165, and ∼175 kDa proteins were identified as plasmin-sensitive protein (Pls) by mass spectrometry. Previously, Pls has been demonstrated to be a virulence factor in a mouse septic arthritis model. The pls gene is encoded by the staphylococcal cassette chromosome (SCC)mec type I in MRSA that also encodes the methicillin resistance-conferring mecA and further genes. In a search for glycosyltransferases, we identified two open reading frames encoded downstream of pls on the SCCmec element, which we termed gtfC and gtfD. Expression and deletion analysis revealed that both gtfC and gtfD mediate glycosylation of Pls. Additionally, the recently reported glycosyltransferases SdgA and SdgB are involved in Pls glycosylation. Glycosylation occurs at serine residues in the Pls SD-repeat region and modifying carbohydrates are N-acetylhexosaminyl residues. Functional characterization revealed that Pls can confer increased biofilm formation, which seems to involve two distinct mechanisms. The first mechanism depends on glycosylation of the SD-repeat region by GtfC/GtfD and probably also involves eDNA, while the second seems to be independent of glycosylation as well as eDNA and may involve the centrally located G5 domains. Other previously known Pls properties are not related to the sugar modifications. In conclusion, Pls is a glycoprotein and Pls glycosyl

  3. 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.

  4. Structural Insights into the Anti-methicillin-resistant Staphylococcus aureus (MRSA) Activity of Ceftobiprole*

    PubMed Central

    Lovering, Andrew L.; Gretes, Michael C.; Safadi, Susan S.; Danel, Franck; de Castro, Liza; Page, Malcolm G. P.; Strynadka, Natalie C. J.

    2012-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is an antibiotic-resistant strain of S. aureus afflicting hospitals and communities worldwide. Of greatest concern is its development of resistance to current last-line-of-defense antibiotics; new therapeutics are urgently needed to combat this pathogen. Ceftobiprole is a recently developed, latest generation cephalosporin and has been the first to show activity against MRSA by inhibiting essential peptidoglycan transpeptidases, including the β-lactam resistance determinant PBP2a, from MRSA. Here we present the structure of the complex of ceftobiprole bound to PBP2a. This structure provides the first look at the molecular details of an effective β-lactam-resistant PBP interaction, leading to new insights into the mechanism of ceftobiprole efficacy against MRSA. PMID:22815485

  5. MRSA Infection

    MedlinePlus

    ... MRSA infection By Mayo Clinic Staff Methicillin-resistant Staphylococcus aureus (MRSA) infection is caused by a type ... a fever, see your doctor. Different varieties of Staphylococcus aureus bacteria, commonly called "staph," exist. Staph bacteria ...

  6. Novel inhibitors of the methicillin-resistant Staphylococcus aureus (MRSA)-pyruvate kinase.

    PubMed

    El-Sayed, Mardia Telep; Zoraghi, Roya; Reiner, Neil; Suzen, Sibel; Ohlsen, Knut; Lalk, Michael; Altanlar, Nurten; Hilgeroth, Andreas

    2016-12-01

    Novel bisindolyl-cycloalkane indoles resulted from the reaction of aliphatic dialdehydes and indole. As bisindolyl-natural alkaloid compounds have recently been reported as inhibitors of the methicillin-resistant Staphylococcus aureus (MRSA)-pyruvate kinase (PK), we tested our novel compounds as MRSA PK inhibitors and now report first inhibiting activities. We discuss structure-activity relationships of structurally varied compounds. Activity influencing substituents have been characterized and relations to antibacterial activities of the most active compounds have been proved.

  7. MRSA and multidrug-resistant Staphylococcus aureus in U.S. retail meats, 2010-2011.

    PubMed

    Ge, Beilei; Mukherjee, Sampa; Hsu, Chih-Hao; Davis, Johnnie A; Tran, Thu Thuy T; Yang, Qianru; Abbott, Jason W; Ayers, Sherry L; Young, Shenia R; Crarey, Emily T; Womack, Niketta A; Zhao, Shaohua; McDermott, Patrick F

    2017-04-01

    Methicillin-resistant Staphylococcus aureus (MRSA) has been detected in retail meats, although large-scale studies are scarce. We conducted a one-year survey in 2010-2011 within the framework of the National Antimicrobial Resistance Monitoring System. Among 3520 retail meats collected from eight U.S. states, 982 (27.9%) contained S. aureus and 66 (1.9%) were positive for MRSA. Approximately 10.4% (107/1032) of S. aureus isolates, including 37.2% (29/78) of MRSA, were multidrug-resistant (MDRSA). Turkey had the highest MRSA prevalence (3.5%), followed by pork (1.9%), beef (1.7%), and chicken (0.3%). Whole-genome sequencing was performed for all 66 non-redundant MRSA. Among five multilocus sequence types identified, ST8 (72.7%) and ST5 (22.7%) were most common and livestock-associated MRSA ST398 was assigned to one pork isolate. Eleven spa types were represented, predominately t008 (43.9%) and t2031 (22.7%). All four types of meats harbored t008, whereas t2031 was recovered from turkey only. The majority of MRSA (84.8%) possessed SCCmec IV and 62.1% harbored Panton-Valentine leukocidin. Pulsed-field gel electrophoresis showed that all ST8 MRSA belonged to the predominant human epidemic clone USA300, and others included USA100 and USA200. We conclude that a diverse MRSA population was present in U.S. retail meats, albeit at low prevalence.

  8. Occurrence of methicillin-resistant and -susceptible Staphylococcus aureus within a single colony contributing to MRSA mis-identification.

    PubMed

    Falcão, M H; Texeira, L A; Ferreira-Carvalho, B T; Borges-Neto, A A; Figueiredo, A M

    1999-06-01

    Many methods have been described for the detection of methicillin-resistant Staphylococcus aureus (MRSA), but the homogeneous or heterogeneous expression of methicillin resistance affects the reliability of those methods. This study demonstrates that close association between methicillin-susceptible S. aureus (MSSA) and MRSA strains in the host colonisation site can present additional problems for the detection of MRSA in clinical laboratories, which may contribute to failure in the control of MRSA infection in hospital. Worse, this association may also account for the emergence of MRSA during antibiotic therapy.

  9. 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.

  10. The Economic Burden of Community-Associated Methicillin-Resistant Staphylococcus aureus (CA-MRSA)

    PubMed Central

    Lee, Bruce Y.; Singh, Ashima; David, Michael Z.; Bartsch, Sarah M.; Slayton, Rachel B.; Huang, Susan S.; Zimmer, Shanta M.; Potter, Margaret A.; Macal, Charles M.; Lauderdale, Diane S.; Miller, Loren G.; Daum, Robert S.

    2012-01-01

    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 $2,277 – $3,200 and society $7,070 – $20,489, depending on patient age. In the United States (US), CA-MRSA imposes an annual burden of $478 million - 2.2 billion on third-party payers and $1.4 billion - 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), respectively. Hospitalization rates and mortality are important cost drivers. CA-MRSA confers a substantial economic burden to 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. PMID:22712729

  11. Short communication: Outbreak of methicillin-resistant Staphylococcus aureus (MRSA)-associated mastitis in a closed dairy herd.

    PubMed

    Guimarães, F F; Manzi, M P; Joaquim, S F; Richini-Pereira, V B; Langoni, H

    2017-01-01

    Cows are probably the main source of contamination of raw milk with Staphylococcus aureus. Mammary glands with subclinical mastitis can shed large numbers of Staph. aureus in milk. Because of the risk of this pathogen to human health as well as animal health, the aim of this paper was to describe an outbreak of mastitis caused by methicillin-resistant Staph. aureus (MRSA), oxacillin-susceptible mecA-positive Staph. aureus (OS-MRSA), and methicillin-susceptible Staph. aureus (MSSA) on a dairy farm. Milk samples were obtained from all quarters, showing an elevated somatic cell count by the California Mastitis Test. The isolates were identified by phenotypic and genotypic methods. Staphylococcus spp. were isolated from 53% (61/115) of the milk samples, with 60 isolates identified as Staph. aureus (98.4%) and 1 isolate identified as Staphylococcus epidermidis (1.6%). The presence of the mecA gene was verified in 48.3% of Staph. aureus isolates. Of the Staph. aureus isolates, 23.3% were MRSA and 25.0% were OS-MRSA. The total of mastitis cases infected with MRSA was 12.2%. The detection of this large percentage of mastitis cases caused by MRSA and OS-MRSA is of great concern for the animals' health, because β-lactams are still the most important antimicrobials used to treat mastitis. In addition, Staph. aureus isolates causing bovine mastitis represent a public health risk.

  12. MRSA

    MedlinePlus

    ... a long time, even after you leave the hospital. Be sure to follow instructions on how to care for your infection at home . Support Groups For more information about MRSA, see the Centers for Disease Control web site: www.cdc.gov/mrsa . Outlook (Prognosis) ...

  13. 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.

  14. Antibacterial activity of honey against community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA).

    PubMed

    Maeda, Yasunori; Loughrey, Anne; Earle, J A Philip; Millar, B Cherie; Rao, Juluri R; Kearns, Angela; McConville, Ogie; Goldsmith, Colin E; Rooney, Paul J; Dooley, James S G; Lowery, Colm J; Snelling, William J; McMahon, Ann; McDowell, David; Moore, John E

    2008-05-01

    Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has now been described globally, as a clinically significant pathogen, particularly associated with skin and soft tissue infections, including abscesses, cellulitis and furunculosis. The recent emergence of CA-MRSA combined with its predominant presentation associated with skin and soft tissue infection, the previous literature indicating honey as an effective treatment of healthcare-associated HA-MRSA-related wound infection, as well as honey's ease of topical application, make the current study timely and of interest to healthcare practitioners involved with wound management. Although previous studies have examined the antimicrobial activity of honey against HA-MRSA, such data are limited regarding the activity of honey against this emerging type of MRSA. CA-MRSA (n=6 isolates), was examined for its susceptibility to natural honey (n=3 honey produced from bees in Northern Ireland and one commercial French honey). Results demonstrated that all honey was able to reduce the cultural count of all CA-MRSA from approximately 10(6) colony-forming units (cfus) (mean = 6.46 log10 cfu/g) to none detectable within 24h of co-culture of separate CA-MRSA organisms individually with all four-honey types examined. Subsequent non-selective enrichment of honey demonstrated that inoculated honey remained positive for CA-MRSA until 72h postinoculation, after which point no culturable organisms could be detected. This study demonstrated that, in vitro, these natural products had an antimicrobial activity against the CA-MRSA organisms tested. Further studies are now required to demonstrate if this antimicrobial activity has any clinical application.

  15. 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

  16. 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.

  17. 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

    2015-10-16

    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.

  18. 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

  19. 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.

  20. 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

  1. 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

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

    2008-02-01

    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.

  2. 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.

  3. Risk of Skin and Soft Tissue Infections among Children Found to be Staphylococcus aureus MRSA USA300 Carriers

    PubMed Central

    Immergluck, Lilly Cheng; Jain, Shabnam; Ray, Susan M.; Mayberry, Robert; Satola, Sarah; Parker, Trisha Chan; Yuan, Keming; Mohammed, Anaam; Jerris, Robert C.

    2017-01-01

    Introduction The purpose of this study was to examine community-associated methicillin resistant Staphylococcus aureus (CA-MRSA) carriage and infections and determine risk factors associated specifically with MRSA USA300. Methods We conducted a case control study in a pediatric emergency department. Nasal and axillary swabs were collected, and participants were interviewed for risk factors. The primary outcome was the proportion of S. aureus carriers among those presenting with and without a skin and soft tissue infection (SSTI). We further categorized S. aureus carriers into MRSA USA300 carriers or non-MRSA USA300 carriers. Results We found the MRSA USA300 carriage rate was higher in children less than two years of age, those with an SSTI, children with recent antibiotic use, and those with a family history of SSTI. MRSA USA300 carriers were also more likely to have lower income compared to non-MRSA USA300 carriers and no S. aureus carriers. Rates of Panton-Valentine leukocidin (PVL) genes were higher in MRSA carriage isolates with an SSTI, compared to MRSA carriage isolates of patients without an SSTI. There was an association between MRSA USA300 carriage and presence of PVL in those diagnosed with an abscess. Conclusion Children younger than two years were at highest risk for MRSA USA300 carriage. Lower income, recent antibiotic use, and previous or family history of SSTI were risk factors for MRSA USA300 carriage. There is a high association between MRSA USA300 nasal/axillary carriage and presence of PVL in those with abscesses. PMID:28210352

  4. 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

  5. Multicenter evaluation of the LightCycler methicillin-resistant Staphylococcus aureus (MRSA) advanced test as a rapid method for detection of MRSA in nasal surveillance swabs.

    PubMed

    Peterson, Lance R; Liesenfeld, Oliver; Woods, Christopher W; Allen, Stephen D; Pombo, David; Patel, Parul A; Mehta, Maitry S; Nicholson, Bradly; Fuller, DeAnna; Onderdonk, Andrew

    2010-05-01

    The rate of methicillin-resistant Staphylococcus aureus (MRSA) infection continues to rise in many health care settings. Rapid detection of MRSA colonization followed by appropriate isolation can reduce transmission and infection. We compared the performance of the new Roche LightCycler MRSA advanced test to that of the BD GeneOhm MRSA test and culture. Double-headed swabs were used to collect anterior nasal specimens from each subject. For both tests, DNA was extracted and real-time PCR was performed according to manufacturer's instructions. For culture, one swab of the pair was plated directly to CHROMagar MRSA. The swab paired with the BD GeneOhm MRSA test was also placed into an enrichment broth and then plated to CHROMagar MRSA. Colonies resembling staphylococci were confirmed as S. aureus by standard methods. Discrepant specimens had further testing with additional attempts to grow MRSA as well as sample amplicon sequencing. Agreement between results for the two swabs was 99.3% for those with valid results. A total of 1,402 specimens were tested using direct culture detection of MRSA as the gold standard; 187 were culture positive for MRSA. The LightCycler MRSA advanced test had relative sensitivity and specificity of 95.2% (95% confidence interval [CI]: 91.1% to 97.8%) and 96.4% (95% CI: 95.2% to 97.4%), respectively. The BD GeneOhm assay had relative sensitivity and specificity of 95.7% (95% CI: 91.7% to 98.1%) and 91.7% (95% CI: 90.0% to 93.2%), respectively. Following discrepancy analysis, the relative sensitivities of the LightCycler MRSA advanced test and the BD GeneOhm MRSA assay were 92.2 and 93.2%, respectively; relative specificities were 98.9 and 94.2%, respectively. Specificity was significantly better (P<0.001) with the LightCycler MRSA advanced test. The sensitivity of direct culture was 80.4%. The LightCycler MRSA advanced test is a useful tool for sensitive and rapid detection of MRSA nasal colonization.

  6. [Antibiotics for treatment of infections by methicillin-resistant Staphylococcus aureus (MRSA)].

    PubMed

    Stahlmann, R

    2014-10-01

    Over the last 50 years methicillin-resistant S. aureus (MRSA) spread globally. Vancomycin is still the most recommended antibiotic for MRSA-infections. Teicoplanin is an alternative glycopeptide with longer elimination half-life. Telavancin is a more recently developed derivative of vancomycin with similar clinical efficacy as vancomycin. It is not recommended for treatment of patients with renal insufficiency. Nephrotoxicity limits the therapeutic use of glycopeptide antibiotics. The oxazolidinone linezolid exhibits similar to superior therapeutic efficacy. Hematologic controls are necessary during treatment with this antibacterial agent. Neurotoxic effects have been observed mainly in patients who received prolonged linezolid treatment. Attention must be paid to possible interactions with concomitantly given drugs acting on the serotonergic system. New therapeutic options arise with ceftaroline, the first β-lactam antibiotic with activity against MRSA. However, controlled clinical trials with pulmonary MRSA infections have not been conducted with ceftaroline. Daptomycin, a lipopeptide, and tigecycline, a glycylcyclin are active in vitro against MRSA as well, but are also not indicated in pulmonary MRSA infections. These antibiotics show in an exemplary manner that antibacterial activity in vitro is an important prerequisite, but relevant data for a therapeutic decision should be derived from randomized controlled clinical double-blind trials.

  7. Prevalence of methicillin resistant Staphylococcus aureus [MRSA] colonization or carriage among health-care workers.

    PubMed

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

    2016-01-01

    In Oman, the prevalence of health care associated methicillin resistant Staphylococcus aureus [HA-MRSA] is unknown. Therefore, to estimate the prevalence of HA-MRSA, we collected nasal swabs and swabs from cell phones on sterile polyester swabs and immediately inoculated on the mannitol salt agar containing oxacillin from medical students and hospital health care providers. Antibiotic susceptibility testing of the isolates was then performed using the Kirby Bauer's disc diffusion method. Additionally, a brief survey questionnaire was used to acquire demographic data. Amongst the 311 participants enrolled, nasal colonization with HA-MRSA was found in 47 individuals (15.1%, 95% confidence interval [CI]=11.1%, 19.1%). HA-MRSA was also isolated from the cell phone surfaces in 28 participants (9.0%, 95% CI=8.6%, 9.3%). 5 participants (1.6%) showed positive results both from their nasal swabs and from their cell phones. Antibiotic resistance to erythromycin [48%] and clindamycin [29%] was relatively high. 9.3% HA-MRSA isolates were vancomycin resistant [6.6% nasal carriage]. There was no statistically significant correlation between HA-MRSA isolates and the demographic characteristics or the risk factors namely gender, underlying co-morbidities like diabetes, hypertension, skin/soft tissue infections, skin ulcers/wounds, recent exposure to antibiotics, or hospital visits (p>0.05, Chi-square test).

  8. Presence of Methicillin Resistant Staphylococcus aureus (MRSA) in sewage treatment plant.

    PubMed

    Boopathy, Raj

    2017-02-23

    The presence of antibiotic resistant bacteria and antibiotic resistance genes in rural sewage treatment plants are not well reported in the literature. The aim of the present study was to study the frequency occurrence of Methicillin Resistant Staphylococcus aureus (MRSA) in a rural sewage treatment plant. This study was conducted using raw sewage as well as treated sewage from a small town sewage treatment plant in rural southeast Louisiana of USA. Results showed the presence of MRSA consistently in both raw and treated sewage. The presence of mecA gene responsible for methicillin resistance was confirmed in the raw and treated sewage water samples.

  9. 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.

  10. 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

  11. 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

  12. 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...

  13. Performance of CHROMagar Staph aureus and CHROMagar MRSA for detection of Staphylococcus aureus in seawater and beach sand--comparison of culture, agglutination, and molecular analyses.

    PubMed

    Goodwin, K D; Pobuda, M

    2009-11-01

    Beach seawater and sand were analyzed for Staphylococcus aureus and methicillin resistant S. aureus (MRSA) for samples collected from Avalon, and Doheny Beach, CA. Membrane filtration followed by incubation on CHROMagar Staph aureus (SCA) and CHROMagar MRSA (C-MRSA) was used to enumerate S. aureus and MRSA, respectively. Media performance was evaluated by comparing identification via colony morphology and latex agglutination tests to PCR (clfA, 16S, and mecA genes). Due to background color and crowding, picking colonies from membrane filters and streaking for isolation were sometimes necessary. The specificity of SCA and C-MRSA was improved if colony isolates were identified by the presence of a matte halo in addition to mauve color; however routine agglutination testing of isolates did not appear warranted. Using the appearance of a colony on the membrane filter in conjunction with isolate appearance, the positive % agreement, the negative % agreement, and the % positive predictive accuracy for SCA was 84%, 95%, and 99% respectively, and for C-MRSA it was 85%, 98%, and 92%, respectively. Sensitivity and specificity of SCA and C-MRSA with membrane-filtered beach samples were optimized through identification experience, control of filter volume and incubation time, and isolation of colonies needing further identification. With optimization, SCA and C-MRSA could be used for enumeration of S. aureus and MRSA from samples of beach water and sand. For the sites studied here, the frequency of detection of S. aureus ranged from 60 to 76% and 53 to 79% for samples of beach seawater and sand, respectively. The frequency of detection of MRSA ranged from 2 to 9% and 0 to 12% for samples of seawater and sand, respectively.

  14. 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...

  15. 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...

  16. 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%.

  17. Twenty-Five Year Epidemiology of Invasive Methicillin-Resistant Staphylococcus aureus (MRSA) Isolates Recovered at a Burn Center

    DTIC Science & Technology

    2009-01-01

    Twenty-five year epidemiology of invasive methicillin- resistant Staphylococcus aureus (MRSA) isolates recovered at a burn center§ Clinton K. Murray...history: Accepted 12 February 2009 Keywords: Burn center Epidemiology Methicillin-resistant Staphylococcus aureus Antimicrobial susceptibility a b s t r...invasive MRSA isolates over 25 years at a single burn unit. Isolates were tested by pulsed-field gel electrophoresis (PFGE), broth microdilution

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. 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

  4. Alarming proportions of methicillin-resistant Staphylococcus aureus (MRSA) in wound samples from companion animals, Germany 2010-2012.

    PubMed

    Vincze, Szilvia; Stamm, Ivonne; Kopp, Peter A; Hermes, Julia; Adlhoch, Cornelia; Semmler, Torsten; Wieler, Lothar H; Lübke-Becker, Antina; Walther, Birgit

    2014-01-01

    Staphylococcus (S.) aureus is an important cause of wound infections in companion animals, and infections with methicillin-resistant S. aureus (MRSA) are of particular concern due to limited treatment options and their zoonotic potential. However, comparable epidemiological data on MRSA infections in dogs, cats and horses is scarce, also limiting the knowledge about possible links to MRSA isolates from human populations. To gain more knowledge about the occurrence and genotypic variation of MRSA among wound swabs of companion animal origin in Germany we performed a survey (2010-2012) including 5,229 samples from 1,170 veterinary practices. S. aureus was identified in 201 (5.8%) canine, 140 (12.2%) feline and 138 (22.8%) equine swabs from a total of 3,479 canine, 1,146 feline and 604 equine wounds, respectively. High MRSA rates were identified with 62.7%, 46.4% and 41.3% in S. aureus of canine, feline and equine origin, respectively. Further genotyping including spa typing and multilocus sequence typing (MLST) revealed a comparable distribution of spa types among canine and feline MRSA with CC22 (47.6%; 49.2%) and CC5 (30.2%; 29.2%) as predominant lineages followed by CC398 (13.5%; 7.7%) and CC8 (4.0%; 9.2%). In contrast, the majority of equine MRSA belonged to CC398 (87.7%). Our data highlight the importance of S. aureus and MRSA as a cause of wound infections, particularly in cats and horses in Germany. While "human-associated" MRSA lineages were most common in dogs and cats, a remarkable number of CC398-MRSA was detected in horses, indicating a replacement of CC8-MRSA as the predominant lineage within horses in Germany. These data enforce further longitudinal epidemiological approaches to examine the diversity and temporal relatedness of MRSA populations in humans and animals to assess probable sources of MRSA infections. This would enable a sound risk assessment and establishment of intervention strategies to limit the additional spread of MRSA.

  5. 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

  6. 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.

  7. Molecular-Characterization of Methicillin-Resistance Staphylococcus aureus (MRSA) from Different Tertiary Care Hospitals in Bangladesh.

    PubMed

    Roy, S; Barman, T K; Hossain, M A; Paul, S K; Haque, N; Ahmed, S; Nasreen, S A; Hossain, M S; Sarkar, S R; Kubayashi, N; Laskar, N

    2017-01-01

    Infections caused by Staphylococcus aureus were treated by methicillin, but about 95% of S. aureus has been resistance to methicillin, both in the community and hospitals and are increasing day by day. MRSA produces altered penicillin binding protein, PBP2a, due to the expression of mecA gene. Some strains of both the MRSA and MSSA carry PVL gene. This cross sectional observational study was conducted to detect the molecular-characterization of methicillin resistant Staphylococcus aureus (MRSA) and carried out in the Department of Microbiology, Mymensingh Medical College from July 2014 to December 2015. Clinical samples for this study were wound swab, pus, exudates from diabetic ulcer and burn ulcer, aural swab, blood and urine which were collected from three tertiary care hospitals such as from MMCH, BIRDEM hospital and SSMCH. Standard microbiological procedure & biochemical tests were carried out to detect S. aureus. Oxacillin disk diffusion method (ODDM) was done by Kirby-Bauer disk diffusion method. Out of a total 109 culture positive samples 69 isolates of S. aureus were selected for the study. Among the 69 isolates 33, 27 and 09 were from MMCH, BIRDEM hospital and SSMCH respectively. Among the 69 isolates, 17(24.6%) and 52(75.3%) were distinguished as MRSA and MSSA respectively by ODDM. In contrast, detection of presence and absence of mecA gene by PCR identified 20(28.9%) and 49(71.01%) isolates as MRSA and MSSA respectively. Multiplex PCR was performed by standard protocol with specific primers for detection of 16S rRNA gene for Staphylococcus, nuc gene for Staphylococcus aureus, mecA gene for MRSA, PVL gene as a virulence factor and ACME-arc gene for worldwide spreading USA 300 MRSA clone. The PVL gene were detected in 3 out of 20 MRSA (15%) and 19 out of 49 MSSA (38.7%) and the ACME- arc gene was not found in any isolates. All of the S. aureus (MRSA and MSSA) isolates were sensitive to Vancomycin and Gentamicin. All MRSA isolates (100%) showed resistance

  8. 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

  9. 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

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

    2009-12-01

    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.

  10. Clinical outcomes and treatment approach for community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infections in Israel.

    PubMed

    Berla-Kerzhner, E; Biber, A; Parizade, M; Taran, D; Rahav, G; Regev-Yochay, G; Glikman, D

    2017-01-01

    Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infections are increasingly documented worldwide. We recently identified two major CA-MRSA clones in Israel: USA300 and t991. Here, we assessed clinical outcomes by CA-MRSA clones and the physicians' treatment approach to CA-MRSA infections. All community-onset, clinical MRSA isolates detected during 2011-2013 by Maccabi Healthcare Services were collected and characterized phenotypically and genotypically; data were collected retrospectively from electronic medical records. Of 309 patients with MRSA infections, 64 were identified as CA-MRSA (21 %). Of the CA-MRSA infections, 72 % had skin and soft tissue infections (SSTIs), 38 % were Panton-Valentine leukocidin (PVL)+, the major clone being USA300 (n = 13, 54 %). Of PVL- isolates (n = 40, 62 %), t991 was the major clone. Age was the only predictor for PVL+ CA-MRSA infection (p < 0.001). Patients with PVL+ CA-MRSA had higher incidence of SSTI recurrences (1.061 vs. 0.647 events per patient/per year, p < 0.0001) and were more likely to have the SSTI drained (64 % vs. 21 %, p = 0.003) when compared to PVL- CA-MRSA. USA300 was more common among adults, while t991 was more common among children (p = 0.002). The physician's referral to culture results and susceptibility were the only predictors of appropriate antibiotic therapy (p < 0.001). However, only a minority of physicians referred to culture results, regardless of subspecialties. PVL+ CA-MRSA isolates caused significantly more recurrences of SSTIs and increased the need for drainage compared with PVL- isolates. Physicians' awareness of CA-MRSA as a cause of SSTIs in the community was suboptimal. Culturing of pus-producing SSTIs is crucial for providing adequate antimicrobials and elucidating MRSA epidemiology.

  11. 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.

  12. 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.

  13. 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

  14. Methicillin-resistant Staphylococcus aureus (MRSA) on the skin of long-term hospitalised horses.

    PubMed

    Van den Eede, A; Hermans, K; Van den Abeele, A; Floré, K; Dewulf, J; Vanderhaeghen, W; Crombé, F; Butaye, P; Gasthuys, F; Haesebrouck, F; Martens, A

    2012-08-01

    Given the significance of methicillin-resistant Staphylococcus aureus (MRSA) infections for both horses and staff in equine veterinary hospitals, protocols are required to minimise the risk of nosocomial transmission, including the screening of the skin and nasal chambers of equine patients for evidence of infection. The objective of this study was to clarify the potential existence and extent of MRSA on the skin of horses requiring long-term hospitalisation (≥ 6 months). Thirty such horses were sampled at eight different locations on their skin and from their nasal chambers. MRSA was isolated from 12 animals (40%), with all sample sites testing positive on at least one occasion. Organisms were most frequently detected in the nasal chambers (relative sensitivity, 83.3%; 34.5% positive horses; isolation rate 33.3%). Skin presence was found in 30% of animals with the highest isolation rates found at the carpus (16.7%), neck, withers and croup (13.3% each). To achieve a relative screening sensitivity of >90%, at least one skin site was required in addition to nasal sampling. This evidence of skin as well as nasal reservoirs of MRSA in long-term hospitalised horses should facilitate the design of effective screening and containment protocols.

  15. 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

  16. [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.

  17. Report - Antibacterial activity of sea buckthorn (Hippophae rhamnoides L.) against methicillin resistant Staphylococcus aureus (MRSA).

    PubMed

    Qadir, Muhammad Imran; Abbas, Khizar; Younus, Adnan; Shaikh, Rehan Sadiq

    2016-09-01

    Objective of the present study was to investigate the antibacterial activity of Sea buckthorn (Hippophae rhamnoides L.) berries and leaves against methicillin resistant Staphylococcus aureus (MRSA) by using the standard disc diffusion method. Chloroform, n-hexane and aqueous extract of the plant parts were used. Doses of 2mg/ml, 4 mg/ml and 6mg/ml were tested against the microorganism, and the zone of inhibition was compared against the standard drug vancomycin. Results indicated that n-hexane and chloroform extracts of berries and n-hexane extract leaves showed significant (p<0.05) antibacterial activity comparable with vancomycin. It was concluded from the study that extracts berries and leaves of Hippophae rhamnoides have antibacterial activity against MRSA.

  18. Interaction Between Methicillin-Resistant Staphylococcus aureus (MRSA) and Acanthamoeba polyphaga.

    PubMed

    de Souza, Thamires Klein; Soares, Scheila Silva; Benitez, Lisianne Brittes; Rott, Marilise Brittes

    2017-05-01

    The interactions that occur between bacteria and amoebae can give through mutual relations, where both organisms benefit from the association or parasitic in which one organism benefits at the expense of the other. When these organisms share the same environment, it can result in some changes in the growth of organisms, in adaptation patterns, in morphology, development or even in their ability to synthesize proteins and other substances. In this study, the interaction between Acanthamoeba polyphaga and Staphylococcus aureus (MRSA) was evaluated using a co-culture model at different incubation times. The results showed that 89% of amoebic cells remained viable after contact with the bacteria. The bacterial isolate was visualized inside the amoeba through confocal microscopy and fluorescence for up to 216 h of co-cultivation. The lysate of amoebic culture increased the growth of S. aureus (MRSA), and the effect of supernatant of culture inhibited bacterial growth over the incubation times, suggesting that A. polyphaga produced some metabolite, that inhibited the growth of bacteria. Moreover, the encystment of the A. polyphaga was increased by the bacteria presence. The results show that A. polyphaga and S. aureus interaction may have an important influence on survival of both, and specially indicate a possible effect on the metabolics characteristics each other.

  19. 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.

  20. 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.

  1. 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

  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

    2016-08-29

    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.

  3. 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.

  4. 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.

  5. 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.

  6. Potential for pet animals to harbour methicillin-resistant Staphylococcus aureus when residing with human MRSA patients.

    PubMed

    Morris, D O; Lautenbach, E; Zaoutis, T; Leckerman, K; Edelstein, P H; Rankin, S C

    2012-06-01

    Colonization by methicillin-resistant Staphylococcus aureus (MRSA) may be persistent in people and is horizontally transmissible. The scientific literature suggests that domestic pets may also participate in cross-transmission of MRSA within households. The objectives of this study were to evaluate the prevalence of and risk factors for MRSA carriage by pets residing in households with an MRSA-infected person. From 66 households in which an MRSA-infected patient resided, we screened 47 dogs and 52 cats using a swab protocol. Isolates from pets and humans were genotyped using two techniques and compared for concordance. Human participants completed a 22-question survey of demographic and epidemiologic data relevant to staphylococcal transmission. Eleven of 99 pets (11.5%) representing 9 (13.6%) of households were MRSA-positive, but in only six of these households were the human and animal-source strains genetically concordant. Human infection by strain USA 100 was significantly associated with pet carriage [OR = 11.4 (95% CI 1.7, 76.9); P = 0.013]. Yet, for each day of delay in sampling the pet after the person's MRSA diagnosis, the odds of isolating any type of MRSA from the pet decreased by 13.9% [(95% CI 2.6, 23.8); P = 0.017)]. It may be concluded that pets can harbour pandemic strains of MRSA while residing in a household with an infected person. However, the source of MRSA to the pet cannot always be attributed to the human patient. Moreover, the rapid attrition of the odds of obtaining a positive culture from pets over time suggests that MRSA carriage may be fleeting.

  7. 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

  8. 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.

  9. SCC mec typing and antimicrobial resistance of methicillin-resistant Staphylococcus aureus (MRSA) from pigs of Northeast India.

    PubMed

    Rajkhowa, S; Sarma, D K; Pegu, S R

    2016-12-01

    Staphylococcus aureus is one of the most important pathogens of both humans and animal. Methicillin-resistant Staphylococcus aureus (MRSA) is an important human pathogen that causes serious infections both in hospitals and communities due to its multidrug resistance tendency. This study was undertaken to characterize the MRSA isolates from pigs and to determine the antimicrobial resistance of these isolates. Forty nine MRSA strains (one strain per positive pig) isolated from pigs of Northeast India were characterized by SCCmec typing and antimicrobial resistance. The overall prevalence of MRSA was 7.02 % with the highest prevalence recorded in pigs aged 1-3 months (P = 0.001) and in nasal samples (P = 0.005). Two SCC mec types (type III and V) were found in Indian pigs with predominance of type V. All isolates were resistant to penicillin. Seventeen resistance groups were observed where 87.75 % isolates showed multidrug resistance (showed resistance to three or more classes of antimicrobials). The most predominant resistance pattern observed was Oxytetracycline + Penicillin + Sulfadiazine + Tetracycline accounting 12.24 % of the isolates. The present study contributes to the understanding of characteristics and antimicrobial resistance of porcine MRSA isolates which in turn will help in devising strategy for the control of this pathogen. Findings of the study also throw light on multidrug resistance MRSA and emphasize the need for judicious use of antimicrobials in animal practice.

  10. Noninvasive In Vivo Imaging to Evaluate Immune Responses and Antimicrobial Therapy against Staphylococcus aureus and USA300 MRSA Skin Infections

    PubMed Central

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

    2011-01-01

    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. PMID:21191403

  11. Complete Genome Sequence of Staphylococcus aureus XN108, an ST239-MRSA-SCCmec III Strain with Intermediate Vancomycin Resistance Isolated in Mainland China

    PubMed Central

    Zhang, Xia; Xu, Xiaomeng; Yuan, Wenchang; Hu, Qiwen; Shang, Weilong; Hu, Xiaomei

    2014-01-01

    ST239-MRSA-SCCmec III (ST239, sequence type 239; MRSA, methicillin-resistant Staphylococcus aureus; SCCmec III, staphylococcal cassette chromosome mec type III) is the most predominant clone of hospital-acquired methicillin-resistant S. aureus in mainland China. We report here the complete genome sequence of XN108, the first vancomycin-intermediate S. aureus strain isolated from a steam-burned patient with a wound infection. PMID:25059856

  12. 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.

  13. 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.

  14. Diaryltriazenes as antibacterial agents against methicillin resistant Staphylococcus aureus (MRSA) and Mycobacterium smegmatis.

    PubMed

    Vajs, Jure; Proud, Conor; Brozovic, Anamaria; Gazvoda, Martin; Lloyd, Adrian; Roper, David I; Osmak, Maja; Košmrlj, Janez; Dowson, Christopher G

    2017-02-15

    Diaryltriazene derivatives were synthesized and evaluated for their antimicrobial properties. Initial experiments showed some of these compounds to have activity against both methicillin-resistant strains of Staphylococus aureus (MRSA) and Mycobacterium smegmatis, with MICs of 0.02 and 0.03 μg/mL respectively. Those compounds with potent anti-staphylococcal and anti-mycobacterial activity were not found to act as growth inhibitors of mammalian cell lines or yeast. Furthermore, we demonstrated that one of the most active anti-MRSA diaryltriazene derivatives was subject to very low frequencies of resistance at <10(-9). Whole genome sequencing of resistant isolates identified mutations in the enzyme that lysylates phospholipids. This could result in the modification of phospholipid metabolism and consequently the characteristics of the staphylococcal cell membrane, ultimately modifying the sensitivity of these pathogens to triazene challenge. Our work has therefore extended the potential range of triazenes, which could yield novel antimicrobials with low levels of resistance.

  15. Micheliolide provides protection of mice against Staphylococcus aureus and MRSA infection by down-regulating inflammatory response

    PubMed Central

    Jiang, Xinru; Wang, Yuli; Qin, Yifei; He, Weigang; Benlahrech, Adel; Zhang, Qingwen; Jiang, Xin; Lu, Zhenhui; Ji, Guang; Zheng, Yuejuan

    2017-01-01

    A major obstacle to therapy in intensive care units is sepsis caused by severe infection. In recent years gram-positive (G+) bacteria, most commonly staphylococci, are thought to be the main pathogens. Micheliolide (MCL) was demonstrated to provide a therapeutic role in rheumatoid arthritis, inflammatory intestinal disease, colitis-associated cancer, and lipopolysaccharide (LPS, the main component of G− bacterial cell wall) induced septic shock. We proved here that MCL played an anti-inflammatory role in Staphylococcus aureus (S. aureus) and methicillin-resistant S. aureus (MRSA) induced peritonitis. It inhibited the expression of inflammatory cytokines and chemokines in macrophages and dendritic cells upon stimulation with peptidoglycan (PGN, the main cell wall composition of G+ bacteria). PI3K/Akt and NF-κB pathways account for the anti-inflammatory role of MCL after PGN stimulation. MCL reduced IL-6 secretion through down-regulating NF-κB activation and improved the survival status in mice challenged with a lethal dose of S. aureus. In MRSA infection mouse model, MCL down-regulated the expression of IL-6, TNF-α, MCP-1/CCL2 and IFN-γ in sera, and ameliorated the organ damage of liver and kidney. In conclusion, MCL can help maintain immune equilibrium and decrease PGN, S. aureus and MRSA-triggered inflammatory response. These provide the rationality for the potential usage of MCL in sepsis caused by G+ bacteria (e.g., S. aureus) and antibiotic-resistant bacteria (e.g., MRSA). PMID:28165033

  16. 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

  17. 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.

  18. 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.

  19. Methicillin-resistant Staphylococcus aureus (MRSA) pyruvate kinase as a target for bis-indole alkaloids with antibacterial activities.

    PubMed

    Zoraghi, Roya; Worrall, Liam; See, Raymond H; Strangman, Wendy; Popplewell, Wendy L; Gong, Huansheng; Samaai, Toufiek; Swayze, Richard D; Kaur, Sukhbir; Vuckovic, Marija; Finlay, B Brett; Brunham, Robert C; McMaster, William R; Davies-Coleman, Michael T; Strynadka, Natalie C; Andersen, Raymond J; Reiner, Neil E

    2011-12-30

    Novel classes of antimicrobials are needed to address the emergence of multidrug-resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA). We have recently identified pyruvate kinase (PK) as a potential novel drug target based upon it being an essential hub in the MRSA interactome (Cherkasov, A., Hsing, M., Zoraghi, R., Foster, L. J., See, R. H., Stoynov, N., Jiang, J., Kaur, S., Lian, T., Jackson, L., Gong, H., Swayze, R., Amandoron, E., Hormozdiari, F., Dao, P., Sahinalp, C., Santos-Filho, O., Axerio-Cilies, P., Byler, K., McMaster, W. R., Brunham, R. C., Finlay, B. B., and Reiner, N. E. (2011) J. Proteome Res. 10, 1139-1150; Zoraghi, R., See, R. H., Axerio-Cilies, P., Kumar, N. S., Gong, H., Moreau, A., Hsing, M., Kaur, S., Swayze, R. D., Worrall, L., Amandoron, E., Lian, T., Jackson, L., Jiang, J., Thorson, L., Labriere, C., Foster, L., Brunham, R. C., McMaster, W. R., Finlay, B. B., Strynadka, N. C., Cherkasov, A., Young, R. N., and Reiner, N. E. (2011) Antimicrob. Agents Chemother. 55, 2042-2053). Screening of an extract library of marine invertebrates against MRSA PK resulted in the identification of bis-indole alkaloids of the spongotine (A), topsentin (B, D), and hamacanthin (C) classes isolated from the Topsentia pachastrelloides as novel bacterial PK inhibitors. These compounds potently and selectively inhibited both MRSA PK enzymatic activity and S. aureus growth in vitro. The most active compounds, cis-3,4-dihyrohyrohamacanthin B (C) and bromodeoxytopsentin (D), were identified as highly potent MRSA PK inhibitors (IC(50) values of 16-60 nM) with at least 166-fold selectivity over human PK isoforms. These novel anti-PK natural compounds exhibited significant antibacterial activities against S. aureus, including MRSA (minimal inhibitory concentrations (MIC) of 12.5 and 6.25 μg/ml, respectively) with selectivity indices (CC(50)/MIC) >4. We also report the discrete structural features of the MRSA PK tetramer as determined by x

  20. Prevalence and antibiotic susceptibility pattern of methicillin-resistant Staphylococcus aureus (MRSA) among primary school children and prisoners in Jimma Town, Southwest Ethiopia

    PubMed Central

    2013-01-01

    Background Staphylococcus aureus infections are increasingly reported from both health institutions and communities around the world. In particular, infections due to methicillin-resistant Staphylococcus aureus (MRSA) strains have been detected worldwide. If MRSA becomes the most common form of S. aureus in a community, it makes the treatment of common infections much more difficult. But, report on the current status of community acquired MRSA in the study area is scanty. Methods Community-based cross sectional study was conducted to evaluate the current prevalence and antibiotic susceptibility pattern of MRSA among primary school children and prisoners in Jimma town. MRSA was detected using Cefoxitin (30μg) disc; and epidemiologic risk factors were assessed using pre-designed questionnaires distributed to the children’s parents and prisoners. A total of 354 nasal swabs were collected from primary school children and prisoners from December 2010 to March 2011 following standards microbiological methods. Results A total of 169 S. aureus isolates were recovered. The overall prevalence of MRSA among the study population was 23.08 % (39/169). Specifically, the prevalence of MRSA among primary school children and prisoners were 18.8% (27/144) and 48% (12/25), respectively. The isolated S. aureus and MRSA displayed multiple drug resistance (MDR) to 2 to 10 antibiotics. The most frequent MDR was Amp/Bac/Ery/Pen/Fox (resistance to Ampicillin, Bacitracin, Erythromycin, Penicillin, and Cefoxitin). Conclusion The present study revealed that MRSA could be prevalent in the healthy community, transmitted from hospital to the community. The high distribution of MRSA could be favored by potential risk factors. Thus, for comprehensive evaluation of the current prevalence of MRSA and design control measures, consideration need to be given to the healthy community besides data coming from health institutions. PMID:23731679

  1. 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 surveillance…

  2. USA300 Methicillin-Resistant Staphylococcus aureus Bacteremia and the Risk of Severe Sepsis: Is USA300 MRSA Associated with More Severe Infections?

    PubMed Central

    Kreisel, Kristen M.; Stine, O. Colin; Johnson, J. Kristie; Perencevich, Eli N.; Shardell, Michelle D.; Lesse, Alan J.; Gordin, Fred M.; Climo, Michael W.; Roghmann, Mary-Claire

    2011-01-01

    Objective USA300 methicillin-resistant Staphylococcus aureus (MRSA) is increasing as a cause of severe community-associated bacteremic infections. We assessed severe sepsis in response to infection in patients with USA300 MRSA compared to non-USA300 MRSA bacteremia. Methods A cohort study was conducted from 1997–2008 comparing sepsis in response to infection in 271 patients with MRSA bacteremia from four VA hospitals. Results Sixty-seven (25%) patients with MRSA bacteremia were USA300 MRSA; 204 (75%) were non-USA300 MRSA. The proportion of MRSA bacteremia caused by USA300 MRSA increased over time (χ2 p<0.0001). Adjusting for age and nosocomial infection, patients with USA300 MRSA bacteremia were more likely to have severe sepsis or septic shock in response to infection than patients with non-USA300 MRSA bacteremia (adjusted Relative Risk=1.82; 95% CI: 1.16–2.87; p=0.01). Conclusions This suggests that patients with USA300 MRSA are more likely to develop severe sepsis in response to their infection, which could be due to host or bacterial differences. PMID:21558047

  3. 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.

  4. 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

  5. Genotypic and phenotypic characterization of methicillin-resistant Staphylococcus aureus (MRSA) isolated from milk of bovine mastitis.

    PubMed

    Bardiau, M; Yamazaki, K; Duprez, J-N; Taminiau, B; Mainil, J G; Ote, I

    2013-09-01

    The aim of this study was to evaluate the presence of methicillin-resistant Staphylococcus aureus (MRSA) among a (S. aureus) collection (n = 430) isolated from milk of cows suffering from mastitis in Belgium and to compare their genotypic as well as phenotypic characteristics. Pulsed field gel electrophoresis (PFGE) and PCR-based typing techniques (MLST, spa, SCCmec, and agr typing) have been applied and supplemented by capsule serotyping, biofilm production quantification and antimicrobial susceptibility testing. Nineteen MRSA were isolated. Seven distinct ApaI PFGE patterns were observed. All isolates, except one, were identified as ST398 strains. Three spa types (t011, t567 and t108) and two SCCmec types (IV and V) were identified. All isolates belonged to agr type I and capsule type 5 and were Panton-Valentine leukocidin (PVL) negative. All isolates produced biofilm in TSBglc , whereas the majority did not in milk serum. Twelve resistance patterns were observed, with almost two-thirds of the isolates being resistant to at least six antibiotics, including penicillin and tetracycline. Our study confirms that the emerging ST398 LA-MRSA clone has attained Belgian cattle. With regard to genotypic and phenotypic typing, the 19 MRSA isolated in this study form a homogenous group and do not differ much from one another, neither from what has been previously described.

  6. 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

  7. Isolation And Partial Characterization Of Bacteria Activity Associated With Gorgonian Euplexaura sp. Against Methicillin-Resistant Staphylococcus aureus (MRSA)

    NASA Astrophysics Data System (ADS)

    Kristiana, R.; Ayuningrum, D.; Asagabaldan, M. A.; Nuryadi, H.; Sabdono, A.; Radjasa, O. K.; Trianto, A.

    2017-02-01

    Methicillin-resistant Staphylococcus aureus (MRSA) infection has emerged in around the world and has been resistance to ciprofloxacin, erythromycin, clindamycin. The aims of this study were to isolate, to investigate and to characterize bacterial symbionts gorgonian having activity against MRSA. Euplexaura sp. was collected from Panjang Island, Jepara, Indonesia by snorkling 2-5 m in depth. Bacterias were isolated by using spesific media with dilution method. Bacterias were conducted by using the streak method. Antibacterial activity was investigated by overlay method. The potent bacteria was identified by using molecular identification (DNA extraction, electrophoresis, PCR and phylogenetic analysis using 16S rDNA genes with actinobacteria-spesific primers) and bio-chemical test (among 5 isolated bacteria from gorgonian showed activity against MRSA). The strain PG-344 was the best candidat that has an inhibition zone against MRSA. The result of sequencing bacteria is 100% closely related with Virgibacillus salarius. This becomes a potential new bioactive compounds to against MRSA that can be a new drug discovery.

  8. 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.

  9. 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.

  10. Antibacterial mode of action of violacein from Chromobacterium violaceum UTM5 against Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Aruldass, Claira Arul; Masalamany, Santhana Raj Louis; Venil, Chidambaram Kulandaisamy; Ahmad, Wan Azlina

    2017-03-31

    Violacein, violet pigment produced by Chromobacterium violaceum, has attracted much attention recently due to its pharmacological properties including antibacterial activity. The present study investigated possible antibacterial mode of action of violacein from C. violaceum UTM5 against Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) strains. Violet fraction was obtained by cultivating C. violaceum UTM5 in liquid pineapple waste medium, extracted, and fractionated using ethyl acetate and vacuum liquid chromatography technique. Violacein was quantified as major compound in violet fraction using HPLC analysis. Violet fraction displayed bacteriostatic activity against S. aureus ATCC 29213 and methicillin-resistant S. aureus ATCC 43300 with minimum inhibitory concentration (MIC) of 3.9 μg/mL. Fluorescence dyes for membrane damage and scanning electron microscopic analysis confirmed the inhibitory effect by disruption on membrane integrity, morphological alternations, and rupture of the cell membranes of both strains. Transmission electron microscopic analysis showed membrane damage, mesosome formation, and leakage of intracellular constituents of both bacterial strains. Mode of action of violet fraction on the cell membrane integrity of both strains was shown by release of protein, K(+), and extracellular adenosine 5'-triphosphate (ATP) with 110.5 μg/mL, 2.34 μg/mL, and 87.24 ng/μL, respectively, at 48 h of incubation. Violet fraction was toxic to human embryonic kidney (HEK293) and human fetal lung fibroblast (IMR90) cell lines with LC50 value of 0.998 ± 0.058 and 0.387 ± 0.002 μg/mL, respectively. Thus, violet fraction showed a strong antibacterial property by disrupting the membrane integrity of S. aureus and MRSA strains. This is the first report on the possible mode of antibacterial action of violet fraction from C. violaceum UTM5 on S. aureus and MRSA strains.

  11. [Prevention strategies for methicillin-resistant Staphylococcus aureus (MRSA) infections in Latin America].

    PubMed

    Alvarez, Carlos; Labarca, Jaime; Salles, Mauro

    2010-08-01

    After the first reports of the emergence of MRSA in the 1970s, numerous measures intended to prevent its transmission were initiated in hospitals. However, in most cases, large-scale measures failed to be implemented and the transmission of MRSA has since led to a global pandemic. Presently, doubts still remain about the best approach to prevent and control MRSA and more often than not, control measures are not implemented. Therefore, we review here the current situation in Latin America with respect to existing policies for control of MRSA, and evaluate the evidence for control measures in hospitals and the community. We look at the risk factors for infection and transmission of MRSA between hospital patients and within specific populations in the community, and at the effect of antibiotic usage on the spread of MRSA in these settings. Finally, we summarize recommendations for the prevention and control of MRSA, which can be applied to the Latin American hospital environment and community setting.

  12. 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.

  13. Genotyping of methicillin-resistant Staphylococcus aureus (MRSA) isolated from milk and dairy products in South Italy.

    PubMed

    Basanisi, M G; La Bella, G; Nobili, G; Franconieri, I; La Salandra, G

    2017-04-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a pathogen emerging in hospitals as well as community and livestock. MRSA is a significant and costly public health concern because it may enter the human food chain and contaminate milk and dairy products causing foodborne illness. This study aimed to determine the occurrence and the characteristics of MRSA isolated from 3760 samples of milk and dairy products in a previous survey conducted in southern Italy during 2008-2014. Overall out of 484 S. aureus strains isolated, 40 (8.3%) were MRSA and were characterized by spa-typing, Multi-Locus Sequence Typing, SCCmec typing, Staphylococcal enterotoxins (SEs) genes, Panton-Valentine Leukocidin (PVL) genes and ability to form biofilm. The most frequently recovered STs were ST152 (t355-67.5%), followed by ST398 (t899, t108-25%), ST1 (t127-5%) and ST5 (t688-2.5%). All isolates harboured the SCCmec type V (92.5%) or IVa (25%). In one isolate (2.5%), ST398/t899, the SCCmec resulted not detected. Three isolates (7.5%) carried one or more enterotoxin encoding genes (one strain had seg, sei, sem, sen and seo genes; two strains had seh gene). The 50% of isolated strains harboured PVL-encoding genes. Molecular analysis for icaA and icaD genes showed: 72.5% icaA and icaD positive, 25% only icaD gene and one icaA and icaD negative. The detection of MRSA in food of animal origin is a potential health hazard, thus it is necessary monitoring of food-producing animals and improving hygiene standards in food practices in order to reduce the microbiological risk to minimum.

  14. Drug Resistance Reversal Potential of Isoliquiritigenin and Liquiritigenin Isolated from Glycyrrhiza glabra Against Methicillin-Resistant Staphylococcus aureus (MRSA).

    PubMed

    Gaur, Rashmi; Gupta, Vivek Kumar; Singh, Pooja; Pal, Anirban; Darokar, Mahendra Padurang; Bhakuni, Rajendra Singh

    2016-10-01

    Isoliquiritigenin (ISL) and liquiritigenin (LTG) are structurally related flavonoids found in a variety of plants. Discovery of novel antimicrobial combinations for combating methicillin-resistant Staphylococcus aureus (MRSA) infections is of vital importance in the post-antibiotic era. The present study was taken to explore the in vitro and in vivo combination effect of LTG and ISL with β-lactam antibiotics (penicillin, ampicillin and oxacillin) against mec A-containing strains of MRSA. Minimum inhibitory concentration (MIC) of both LTG and ISL exhibited significant anti-MRSA activity (50-100 µg/mL) against clinical isolates of MRSA. The result of in vitro combination study showed that ISL significantly reduced MIC of β-lactam antibiotics up to 16-folds [∑ fractional inhibitory concentration (FIC) 0.312-0.5], while LTG reduced up to 8-folds (∑FIC 0.372-0.5). Time kill kinetics at graded MIC combinations (ISL/LTG + β-lactam) indicated 3.27-9.79-fold and 2.59-3.48-fold reduction in the growth of clinical isolates of S. aureus respectively. In S. aureus-infected Swiss albino mice model, combination of ISL with oxacillin significantly (p < 0.05, p < 0.01, p < 0.001) lowered the systemic microbial burden in blood, liver, kidney, lung and spleen tissues in comparison with ISL, oxacillin alone as well as untreated control. Considering its synergistic antibacterial effect, we suggest both ISL and LTG as promising compounds for the development of novel antistaphylococcal combinations. Copyright © 2016 John Wiley & Sons, Ltd.

  15. One-year experience with modified BD GeneOhm MRSA assay for detection of methicillin-resistant Staphylococcus aureus from pooled nasal, skin, and throat samples.

    PubMed

    Svent-Kucina, Natasa; Pirs, Mateja; Mueller-Premru, Manica; Cvitkovic-Spik, Vesna; Kofol, Romina; Seme, Katja

    2009-02-01

    We report our 1-year experience with modified GeneOhm MRSA assay (formerly IDI-MRSA) for pooled surveillance specimens in low methicillin-resistant Staphylococcus aureus (MRSA) prevalence clinical setting. We have successfully modified the GeneOhm MRSA assay protocol during the specimen preparation step by adding an extra washing step followed by pooling of up to 3 samples per patient (nose, skin, with or without throat) at the lysis step. The sensitivity of the modified assay compared with conventional cultivation was 94.3%, specificity 99.2%, negative predictive value 99.2%, and positive predictive value 94.3%. The modified test is reliable and performed well compared with conventional culture methods in our clinical setting with low-level prevalence of MRSA colonization. Our findings support the use of pooling of the patients samples as a cost-effective way of screening for MRSA colonization.

  16. 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.

  17. Incidence of Staphylococcus aureus isolated from patients treated at the Clinical Center of Skopje, Macedonia, with special attention to MRSA.

    PubMed

    Cekovska, Zaklina; Panovski, Nikola; Petrovska, Milena; Kristóf, Katalin; Rozgonyi, F

    2005-01-01

    The distribution of 3497 Staphylococcus aureus strains according to methicillin resistance, specimens, departmental profession and antibiotic resistance patterns was analysed. The strains were cultured from the patients of the Clinical Center of Skopje, Macedonia, between 1 January 2002 and 31 December 2004. The majority of the isolates was obtained from suppurated wounds (28.5%), nares (21%), intratracheal tubes (13%) and blood cultures (11.8%). Overall 1100 (31.4%) of the isolates was methicillin-resistant with 1 microg oxacillin disc. Of these 35.5%, 30.5% and 10.4% were cultured from wounds, intratracheal tubes and blood samples, respectively. The prevalence of MRSA strains was 78.6%, 75%, 44.2% and 37.3% in specimens of ICU, Coma Center, General Surgery and Haematology patients. There were extremely big differences in the frequency of MRSA between departments with particular specialisation. The 2397 MSSA isolates belonged to practically one antibiotic resistance pattern characterised with penicillin resistance and susceptibility to other antistaphylococcal drugs. The 1100 MRSA isolates distributed to four antibiotic resistance patterns on the basis of their resistance to oxacillin, penicillin, amoxicillin+clavulanic acid, azithromycin, clindamycin, amikacin, gentamicin, ciprofloxacin, trimethoprim+sulphamethoxasole, vancomycin and teicoplanin. All the MRSA isolates were multidrug resistant but sensitive to glycopeptides.

  18. Efficacy of Caltropis procera and Ficus sycomorus extracts in treating MRSA (methicillin-resistant Staphylococcus aureus)-keratitis in rabbit

    PubMed Central

    Sayed, Waiel F.; Salem, Wesam M. A.; Haridy, Mohie A. M.; Hassan, Ne'mat H.

    2015-01-01

    MRSA-induced keratitis in rabbit was used to evaluate the therapeutic effect of F. sycomorus leaves and C. procera latex extracts. Within the 6 rabbit groups tested, group 1 received sterilized saline, while other groups (2 to 6) received 100 μl of intrastromal injections of 1.5×103 colony forming unit (cfu) ml-1 of methicillin-resistant Staphylococcus aureus (MRSA). After 12 hours, groups 3 to 6 also received chloramphenicol, aqueous extract of C. procera latex, aqueous and alcoholic extracts of F. sycomorus leaves, respectively 3 times daily for 12 successive days. The tested extracts inhibited MRSA growth in vitro (i.e. on culture medium). Colony counts in cornea discs from groups 3 to 6 were significantly reduced (P ≤ 0.001) compared to group 2 (untreated). Clinical signs of keratitis were observed on group 2 until the end of experiment. In groups 3 to 6, gradual recovery was observed and signs disappeared by the 12th DPI (days post inoculation). Only mild symptoms persisted in group 5 (aqueous extract of leaves). In group 3 and 5, cornea, iris, ciliary body and conjunctiva showed mild leukocytic infiltration and depigmentation of melanin cells while recovery of cornea and iris was observed in groups 4 and 6. In conclusion, the used extracts have potential therapeutic effects on MRSA-induced keratitis in rabbit. PMID:26648824

  19. 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.

  20. 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.

  1. The herbal-derived honokiol and magnolol enhances immune response to infection with methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA).

    PubMed

    Choi, Eun-Jin; Kim, Hyung-Ip; Kim, Ji-Ae; Jun, Soo Youn; Kang, Sang Hyeon; Park, Dong June; Son, Seok-Jun; Kim, Younghoon; Shin, Ok Sarah

    2015-05-01

    The emergence of antibiotic resistant strains such as methicillin-resistant Staphylococcus aureus (MRSA) reminds us an urgent need to develop a new immune-modulating agent for preventing S. aureus infection. In this study, we found that herbal medicines, honokiol and magnolol, caused a significant cellular immune modulatory effect during S. aureus infection. In mouse macrophages, these compounds drove upregulation of an antioxidant effect in response to S. aureus, resulting in a dampened total cellular reactive oxygen species (ROS) production and decreased production of inflammatory cytokines/chemokines, whereas honokiol induced increased types I and III interferon messenger RNA (mRNA) expression levels in response to MSSA infection. Moreover, the internalization of S. aureus by human alveolar epithelial cells was inhibited by these compounds. Furthermore, honokiol and magnolol treatment promoted a delay in killing during MSSA infection in Caenorhabditis elegans, suggesting antimicrobial function in vivo. In conclusion, honokiol and magnolol may be considered as attractive immune-modulating treatment for S. aureus infection.

  2. 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.

  3. Detection and molecular characterization of a gentamicin-susceptible, methicillin-resistant Staphylococcus aureus (MRSA) clone in Rio de Janeiro that resembles the New York/Japanese clone.

    PubMed

    Melo, M C N; Silva-Carvalho, M C; Ferreira, R L; Coelho, L R; Souza, R R; Gobbi, C N; Rozenbaum, R; Solari, C A; Ferreira-Carvalho, B T; Figueiredo, A M S

    2004-12-01

    Staphylococcus aureus is the leading cause of hospital-acquired infections in many countries, and multiple factors contribute to the ability of these bacteria to disseminate and spread in hospitals. In Brazil it has been demonstrated that a multiresistant methicillin-resistant S. aureus clone, the so-called Brazilian epidemic clone, is widespread geographically. This clone was first detected in 1992 in Brazil, and recently from many other countries within South America, Europe and Asia. The study describes the detection of a gentamicin-susceptible heterogeneous MRSA clone that resembles another MRSA clone widely spread in US and Japanese hospitals, and supports the premise that the detection of heterogeneous MRSA isolates by some recommended methods is a challenging task that may, occasionally, result in MRSA misidentification.

  4. [Treament using a free omental flap for pulmonary Aspergillosis with chronic methicillin-resistant Staphylococcus aureus( MRSA) empyema after fenestration].

    PubMed

    Yabuki, Hiroshi; Tabata, Toshiharu; Sugawara, Takafumi; Fukaya, Ken; Fujimura, Shigefumi

    2013-08-01

    A case is 48-year-old man who had a history of Blalock-Taussig shunt and the radical operation for Fallot's tetralogy, had been performed cavernostomy and fenestration operation for aspergilloma of left upper lobe in the previous hospital due to control blood spitting. Although the contents of the abscess cavity were removed, the opened cavity was again infected by methicillin-resistant Staphylococcus aureus (MRSA) and he was referred to our hospital. The plombage of free omental flap with vascular anastomosis was performed. He has been well without any symptoms or recurrence of empyema for 6 years after surgery.

  5. 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.

  6. 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

  7. 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

  8. 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

    2015-08-05

    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.

  9. Molecular epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) among veterinary students and personnel at a veterinary hospital in Malaysia.

    PubMed

    Aklilu, E; Zunita, Z; Hassan, L; Cheng, Chen Hui

    2013-06-28

    In this study, we report the molecular epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) among veterinary students and personnel in Malaysia. Nasal and oral swabs were collected from 103 veterinary medicine students and 28 personnel from a veterinary hospital. Antibiotic sensitivity test (AST), minimum inhibitory concentration (MIC) test, and PCR amplifications of nucA and mecA gene were performed. Molecular characterization of the isolates was conducted using multilocus sequence typing (MLST), staphylococcal protein A gene (spa) typing, and pulsed-field gel electrophoresis (PFGE). Results from MLST show the presence of the pandemic and widespread MRSA clones, ST5 and ST59. Spa gene typing revealed spa type t267 which has a wide geographical distribution. A new spa type, t5697 was found in this study. Fingerprint analysis by using PFGE show heterogeneity of the isolates. These findings affirm the importance of MRSA in veterinary settings and underscore the need for further extensive research to devise contextual control and prevention strategies.

  10. 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.

  11. 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

  12. 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.

  13. High frequency of occupied attB regions in Norwegian Staphylococcus aureus isolates supports a two-step MRSA screening algorithm.

    PubMed

    Tunsjø, H S; Kalyanasundaram, S; Worren, M M; Leegaard, T M; Moen, A E F

    2017-01-01

    Rapid nucleic acid amplification tests for methicillin-resistant Staphylococcus aureus (MRSA) diagnostics commonly target the mec resistance gene, genes specific for S. aureus, and the integration site for the SCCmec resistance cassette, orfX. Due to poor specificity when these target genes are used individually, additional culture is required to verify positive results. The combination of these targets is useful, but the optimal algorithm may depend on the presence of the genetic markers in S. aureus isolates, as well as the prevalence of MRSA in a population. The aim of the present study was to identify a rapid, low-cost, and functional screening algorithm in order to reduce the response time for MRSA diagnostics. An in-house orfX-SCCmec polymerase chain reaction (PCR) assay was established and evaluated. The results were compared with an existing mec/nuc PCR assay and traditional culture. Methicillin-sensitive S. aureus (MSSA) that tested false-positive in the orfX-SCCmec PCR assay were further investigated with full genome sequencing using the Ion PGM™ System to verify results and causality. Based on these data, a two-step screening algorithm with initial mec/nuc PCR followed by orfX-SCCmec PCR on positive samples was suggested and tested on 1443 patient samples. 22.5 % of MSSA isolates tested false-positive with the orfX-SCCmec PCR. Full genome sequencing of these isolates identified genetic variation in the attB region of S. aureus, including empty cassette variants and non-mec SCC. The suggested two-step MRSA screening algorithm allowed us to report MRSA results for 95.6 % of all samples and 99 % of MRSA-negative samples after one day.

  14. 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…

  15. 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.

  16. 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

  17. 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…

  18. Assessing the probability of acquisition of meticillin-resistant Staphylococcus aureus (MRSA) in a dog using a nested stochastic simulation model and logistic regression sensitivity analysis.

    PubMed

    Heller, J; Innocent, G T; Denwood, M; Reid, S W J; Kelly, L; Mellor, D J

    2011-05-01

    Meticillin-resistant Staphylococcus aureus (MRSA) is an important nosocomial and community-acquired pathogen with zoonotic potential. The relationship between MRSA in humans and companion animals is poorly understood. This study presents a quantitative exposure assessment, based on expert opinion and published data, in the form of a second order stochastic simulation model with accompanying logistic regression sensitivity analysis that aims to define the most important factors for MRSA acquisition in dogs. The simulation model was parameterised using expert opinion estimates, along with published and unpublished data. The outcome of the model was biologically plausible and found to be dominated by uncertainty over variability. The sensitivity analysis, in the form of four separate logistic regression models, found that both veterinary and non-veterinary routes of acquisition of MRSA are likely to be relevant for dogs. The effects of exposure to, and probability of, transmission of MRSA from the home environment were ranked as the most influential predictors in all sensitivity analyses, although it is unlikely that this environmental source of MRSA is independent of alternative sources of MRSA (human and/or animal). Exposure to and transmission from MRSA positive family members were also found to be influential for acquisition of MRSA in pet dogs, along with veterinary clinic attendance and, while exposure to and transmission from the veterinary clinic environment was also found to be influential, it was difficult to differentiate between the importance of independent sources of MRSA within the veterinary clinic. The implementation of logistic regression analyses directly to the input/output relationship within the simulation model presented in this paper represents the application of a variance based sensitivity analysis technique in the area of veterinary medicine and is a useful means of ranking the relative importance of input variables.

  19. Studying the time trend of Methicillin-resistant Staphylococcus aureus (MRSA) in Norway by use of non-stationary γ-Poisson distributions

    PubMed Central

    Moxnes, John F; Moen, Aina E Fossum; Leegaard, Truls Michael

    2015-01-01

    Objectives Study the time development of methicillin-resistant Staphylococcus aureus (MRSA) and forecast future behaviour. The major question: Is the number of MRSA isolates in Norway increasing and will it continue to increase? Design Time trend analysis using non-stationary γ-Poisson distributions. Setting Two data sets were analysed. The first data set (data set I) consists of all MRSA isolates collected in Oslo County from 1997 to 2010; the study area includes the Norwegian capital of Oslo and nearby surrounding areas, covering approximately 11% of the Norwegian population. The second data set (data set II) consists of all MRSA isolates collected in Health Region East from 2002 to 2011. Health Region East consists of Oslo County and four neighbouring counties, and is the most populated area of Norway. Participants Both data sets I and II consist of all persons in the area and time period described in the Settings, from whom MRSA have been isolated. Primary and secondary outcome measures MRSA infections have been mandatory notifiable in Norway since 1995, and MRSA colonisation since 2004. In the time period studied, all bacterial samples in Norway have been sent to a medical microbiological laboratory at the regional hospital for testing. In collaboration with the regional hospitals in five counties, we have collected all MRSA findings in the South-Eastern part of Norway over long time periods. Results On an average, a linear or exponential increase in MRSA numbers was observed in the data sets. A Poisson process with increasing intensity did not capture the dispersion of the time series, but a γ-Poisson process showed good agreement and captured the overdispersion. The numerical model showed numerical internal consistency. Conclusions In the present study, we find that the number of MRSA isolates is increasing in the most populated area of Norway during the time period studied. We also forecast a continuous increase until the year 2017. PMID:26438133

  20. Distribution and characterization of methicillin-resistant Staphylococcus aureus (MRSA) at the small animal hospital, faculty of veterinary medicine, Chiang Mai University, Thailand.

    PubMed

    Patchanee, Prapas; Tadee, Pakpoom; Ingkaninan, Pimlada; Tankaew, Pallop; Hoet, Armando E; Chupia, Vena

    2014-03-01

    Of 416 samples taken from veterinary staff (n = 30), dogs (n = 356) and various environmental sites (n = 30) at the Small Animal Hospital, Faculty of Veterinary Medicine, Chiang Mai University, Thailand, 13 samples contained methicillin-resistant Staphylococcus aureus (MRSA), of which 1 (SCCmec type II) came from veterinarian, 9 (SCCmec types I, III, IVa, V and untypeable) from dogs, and 3 (SCCmec types I, III, and IVb) from environmental samples. The MRSA isolates were 100% susceptible to vancomycin (100%), 69% to cephazolin and 62% to gentamicin, but were up to 92% resistant to tetracycline group, 69% to trimethoprim-sulfamethoxazoles and 62% to ceftriaxone. In addition, all MRSA isolates showed multidrug resistance. As the MRSA isolates from the veterinary staff and dogs were of different SCCmec types, this suggests there were no cross-infections. However, environmental contamination appears to have come from dogs, and appropriate hygienic practices should be introduced to solve this problem.

  1. 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.

  2. 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.

  3. 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…

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. 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

  9. 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

  10. ANTISTAPHYBASE: database of antimicrobial peptides (AMPs) and essential oils (EOs) against methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus aureus.

    PubMed

    Zouhir, Abdelmajid; Taieb, Malek; Lamine, Mohamed Ashraf; Cherif, Ammar; Jridi, Taoufik; Mahjoubi, Basma; Mbarek, Sarra; Fliss, Ismail; Nefzi, Adel; Sebei, Khaled; Ben Hamida, Jeannette

    2017-03-01

    Staphylococcus aureus and methicillin-resistant S. aureus are major pathogens. The antimicrobial peptides and essential oils (EOs) display narrow- or broad-spectrum activity against bacteria including these strains. A centralized resource, such as a database, designed specifically for anti-S. aureus/anti-methicillin-resistant S. aureus antimicrobial peptides and EOs is therefore needed to facilitate the comprehensive investigation of their structure/activity associations and combinations. The database ANTISTAPHYBASE is created to facilitate access to important information on antimicrobial peptides and essential peptides against methicillin-resistant S. aureus and S. aureus. At the moment, the database contains 596 sequences of antimicrobial peptides produced by diverse organisms and 287 essential oil records. It permits a quick and easy search of peptides based on their activity as well as their general, physicochemical properties and literature data. These data are very useful to perform further bioinformatic or chemometric analysis and would certainly be useful for the development of new drugs for medical use. The ANTISTAPHYBASE database is freely available at: https://www.antistaphybase.com/ .

  11. 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.

  12. Incidence and Characterisation of Methicillin-Resistant Staphylococcus aureus (MRSA) from Nasal Colonisation in Participants Attending a Cattle Veterinary Conference in the UK

    PubMed Central

    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. PMID:23869220

  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. General Information about MRSA in Healthcare Settings

    MedlinePlus

    ... CDC Cancel Submit Search The CDC Methicillin-resistant Staphylococcus aureus (MRSA) Note: Javascript is disabled or is ... cause sepsis and death. MRSA is methicillin-resistant Staphylococcus aureus , a type of staph bacteria that is ...

  15. General Information about MRSA in the Community

    MedlinePlus

    ... CDC Cancel Submit Search The CDC Methicillin-resistant Staphylococcus aureus (MRSA) Note: Javascript is disabled or is ... Facebook Tweet Share Compartir MRSA is methicillin-resistant Staphylococcus aureus , a type of staph bacteria that is ...

  16. The Combination of Catechin and Epicatechin Gallate from Fructus Crataegi Potentiates β-Lactam Antibiotics Against Methicillin-Resistant Staphylococcus aureus (MRSA) in Vitro and in Vivo

    PubMed Central

    Qin, Rongxin; Xiao, Kangkang; Li, Bin; Jiang, Weiwei; Peng, Wei; Zheng, Jiang; Zhou, Hong

    2013-01-01

    Fructus crataegi (hawthorn) is the common name of all plant species in the genus Crataegus of the Rosaceae family. In the present study, three monomers of (+)-catechin (C), (−)-epicatechin gallate (ECg) and (−)-epigallocatechin (EGC) were isolated from the hawthorn under the guide of antibacterial sensitization activity. The bioactivity of the composite fraction in enhancing the antibacterial effect of oxacillin against methicillin-resistant Staphylococcus aureus (MRSA) was greater than that of the individual monomer of the hawthorn extract in vitro. Two-fold dilution and checkerboard methods were used to analyze antibacterial activity and screen for the combination and proportion of monomers with the best bioactivity. The result showed that C (128 mg/L) combined with ECg (16 mg/L) had the greatest effect and the combination also reduced the bacterial load in blood of septic mice challenged with a sublethal dose of MRSA, increased daunomycin accumulation within MRSA and down-regulated the mRNA expression of norA, norC and abcA, three important efflux pumps of MRSA. In summary, C and ECg enhanced the antibacterial effect of β-lactam antibiotics against MRSA in vitro and in vivo, which might be related to the increased accumulation of antibiotics within MRSA via suppression of important efflux pumps’ gene expression. PMID:23325048

  17. A methicillin-resistant Staphylococcus aureus (MRSA) Sequence Type 8, spa type t11469 causing infection and colonizing horses in Italy.

    PubMed

    Carfora, Virginia; Caprioli, Andrea; Grossi, Ilaria; Pepe, Marco; Alba, Patricia; Lorenzetti, Serena; Amoruso, Roberta; Sorbara, Luigi; Franco, Alessia; Battisti, Antonio

    2016-06-01

    A Methicillin-resistantStaphylococcus aureus(MRSA) was isolated in Italy from a pathological sample of a mare presenting chronic purulent sinusitis and that had undergone frontal-sinus surgery three months before. Humans, horses, dogs and environmental samples were subsequently collected at the mare's stable and at the Veterinary Hospital, where the mare was operated/hospitalized, and screened for the presence of MRSA that was detected from other horses and from the environment at both sites. All the MRSA isolates belonged to clonal complex (CC)8, ST8-t11469-SCCmec-IVa, and showed similar phenotypic and genetic multidrug resistance patterns and macrorestriction-pulsed-field gel electrophoresis profiles. The only MRSA detected from humans was a CC1, ST1-t127-SCCmec-IVa. This paper represents the first report of a clinical MRSA infection in a horse in Italy. This study also supports the opinion that improper use of antibiotics and hospitalization/surgery can represent risk factors for MRSA colonization/infection in horses, and that the environment is among important sources for exposure.

  18. Livestock-Associated Methicillin Resistant Staphylococcus aureus (LA-MRSA) Clonal Complex (CC) 398 Isolated from UK Animals belong to European Lineages

    PubMed Central

    Sharma, Meenaxi; Nunez-Garcia, Javier; Kearns, Angela M.; Doumith, Michel; Butaye, Patrick R.; Argudín, M. Angeles; Lahuerta-Marin, Angela; Pichon, Bruno; AbuOun, Manal; Rogers, Jon; Ellis, Richard J.; Teale, Christopher; Anjum, Muna F.

    2016-01-01

    In recent years, there has been an increase in the number of livestock-associated methicillin resistant Staphylococcus aureus (LA-MRSA) clonal complex (CC) 398 recovered from S. aureus isolated animals in the UK. To determine possible origins of 12 LA-MRSA CC398 isolates collected after screening more than a thousand S. aureus animal isolates from the UK between 2013 and 2015, whole genome sequences (WGS) of CC398 European, including UK, and non-European isolates from diverse animal hosts were compared. Phylogenetic reconstruction applied to WGS data to assess genetic relatedness of all 89 isolates, clustered the 12 UK CC398 LA-MRSA within the European sub-lineages, although on different nodes; implicating multiple independent incursions into the UK, as opposed to a single introduction followed by clonal expansion. Three UK isolates from healthy pigs and one from turkey clustered within the cassette chromosome recombinases ccr C S. aureus protein A (spa)-type t011 European sub-lineage and three UK isolates from horses within the ccrA2B2 t011 European sub-lineage. The remaining UK isolates, mostly from pigs, clustered within the t034 European lineage. Presence of virulence, antimicrobial (AMR), heavy metal (HMR), and disinfectant (DR) resistance genes were determined using an in-house pipeline. Most, including UK isolates, harbored resistance genes to ≥3 antimicrobial classes in addition to β-lactams. HMR genes were detected in most European ccrC positive isolates, with >80% harboring czrC, encoding zinc and cadmium resistance; in contrast ~60% ccrC isolates within non-European lineages and 6% ccrA2B2 isolates showed this characteristic. The UK turkey MRSA isolate did not harbor φAVβ avian prophage genes (SAAV_2008 and SAAV_2009) present in US MSSA isolates from turkey and pigs. Absence of some of the major human-associated MRSA toxigenic and virulence genes in the UK LA-MRSA animal isolates was not unexpected. Therefore, we can conclude that the 12 UK LA-MRSA

  19. Livestock-Associated Methicillin Resistant Staphylococcus aureus (LA-MRSA) Clonal Complex (CC) 398 Isolated from UK Animals belong to European Lineages.

    PubMed

    Sharma, Meenaxi; Nunez-Garcia, Javier; Kearns, Angela M; Doumith, Michel; Butaye, Patrick R; Argudín, M Angeles; Lahuerta-Marin, Angela; Pichon, Bruno; AbuOun, Manal; Rogers, Jon; Ellis, Richard J; Teale, Christopher; Anjum, Muna F

    2016-01-01

    In recent years, there has been an increase in the number of livestock-associated methicillin resistant Staphylococcus aureus (LA-MRSA) clonal complex (CC) 398 recovered from S. aureus isolated animals in the UK. To determine possible origins of 12 LA-MRSA CC398 isolates collected after screening more than a thousand S. aureus animal isolates from the UK between 2013 and 2015, whole genome sequences (WGS) of CC398 European, including UK, and non-European isolates from diverse animal hosts were compared. Phylogenetic reconstruction applied to WGS data to assess genetic relatedness of all 89 isolates, clustered the 12 UK CC398 LA-MRSA within the European sub-lineages, although on different nodes; implicating multiple independent incursions into the UK, as opposed to a single introduction followed by clonal expansion. Three UK isolates from healthy pigs and one from turkey clustered within the cassette chromosome recombinases ccr C S. aureus protein A (spa)-type t011 European sub-lineage and three UK isolates from horses within the ccrA2B2 t011 European sub-lineage. The remaining UK isolates, mostly from pigs, clustered within the t034 European lineage. Presence of virulence, antimicrobial (AMR), heavy metal (HMR), and disinfectant (DR) resistance genes were determined using an in-house pipeline. Most, including UK isolates, harbored resistance genes to ≥3 antimicrobial classes in addition to β-lactams. HMR genes were detected in most European ccrC positive isolates, with >80% harboring czrC, encoding zinc and cadmium resistance; in contrast ~60% ccrC isolates within non-European lineages and 6% ccrA2B2 isolates showed this characteristic. The UK turkey MRSA isolate did not harbor φAVβ avian prophage genes (SAAV_2008 and SAAV_2009) present in US MSSA isolates from turkey and pigs. Absence of some of the major human-associated MRSA toxigenic and virulence genes in the UK LA-MRSA animal isolates was not unexpected. Therefore, we can conclude that the 12 UK LA-MRSA

  20. 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

  1. The increase of methicillin-resistant Staphylococcus aureus (MRSA) and the presence of an unusual sequence type ST49 in slaughter pigs in Switzerland

    PubMed Central

    2011-01-01

    Background In years past, methicillin-resistant S. aureus (MRSA) has been frequently detected in pigs in Europe, North America and Asia. Recent, yet sporadic studies have revealed a low occurrence of MRSA in Switzerland. In 2009, a monitoring survey of the prevalence and genetic diversity of methicillin-resistant S. aureus (MRSA) in slaughter pigs in Switzerland was conducted using methods recommended by the EU guidelines, and using a sampling strategy evenly distributed throughout the year and representative of the Swiss slaughter pig population. Monitoring should determine if the overall prevalence of MRSA in the entire country is increasing over the years and if specific multi-resistant MRSA clones are spreading over the country. Results In 2009, the nasal cavities of eight out of 405 randomly selected pigs were positive for MRSA, representing a prevalence of 2.0% (95% CI 0.9-3.9). The following year, 23 out of 392 pigs were positive for MRSA [5.9% prevalence (95% CI 3.8-8.7)]. Three multilocus sequence types (ST), four spa types and two types of staphylococcal cassette chromosome mec (SCCmec) elements were detected. The most frequent genotypes were ST398 (MLST)-(spa)t034-V(SCCmec) (n = 18) and ST49-t208-V (n = 7), followed by ST398-t011-V (n = 4), ST398-t1451-V (n = 1), and ST1-t2279-IVc (n = 1). The isolates displayed resistance to ß-lactams [mecA, (31/31); blaZ, (19/31)]; tetracycline [tet(M), (31/31); tet(K), (30/31)] (n = 31); macrolides and lincosamides [erm(C) (4/31) or erm(A) (18/31)] (n = 22); tiamulin [vga(A)v (9/31) or unknown mechanism (18/31)] (n = 27); trimethoprim [dfr(G) (18/31); spectinomycin [ant(9)-Ia (19/31) or unknown mechanism (3/31)] (n = 22); streptomycin [str (19/31)]; sulphamethoxazole (7/31) and ciprofloxacin (n = 1) (mechanisms not determined). Conclusions This study is the first to describe the presence of MRSA ST49 in slaughter pigs, and to demonstrate a significant and nearly three-fold increase of MRSA prevalence in pigs within

  2. Evaluation of the nasal microbiota in slaughter-age pigs and the impact on nasal methicillin-resistant Staphylococcus aureus (MRSA) carriage

    PubMed Central

    2014-01-01

    Background The nasal microbiota of pigs has been poorly assessed but could play a role in carriage of important microorganisms such as methicillin-resistant Staphylococcus aureus (MRSA). The objectives of this study were to describe the nasal microbiota in slaughter age pigs, to evaluate the impact of farm management on the nasal microbiota and to provide a preliminary assessment of the influence of the microbiota on MRSA carriage. Results Nasal swabs were collected from five MRSA positive and eight MRSA negative pigs on one farm that used a liquid feeding system and routine tylosin treatment, and seven MRSA negative pigs from an antibiotic-free farm that used conventional feeding. A total of 946310 sequences passed all quality control filters. The number of sequences per sample ranged from 4307 to 165656 (mean 56092, SD 40007). CatchAll analysis of richness predicted a mean of 1749 OTUs (range 213–3736, SD 996). Overall, 6291 OTUs were identified, yet 5125 (81%) were identified less than 10 times and the 12 most abundant OTUs accounted for 80.7% of sequences. Proteobacteria predominated in all but two samples. Liquid-fed/tylosin-exposed pigs had significantly lower relative abundances of Verrucomicrobia (P = 0.004), Fibrobacteres (P = <0.0001) and sequences unclassified at the phylum level (P = 0.028). When comparing only liquid-fed pigs, MRSA carriers had significantly more Bacteroidetes (P = 0.037) than MRSA negative pigs. 124 genera were identified, with Moraxella accounting for 35.4% of sequences. In the Jaccard index tree, five of eight MRSA positive pigs clustered closely together, as did six of the seven conventionally-fed pigs. A significant difference was identified between conventional and liquid-fed pigs using parsimony test with the Jaccard (P < 0.001) but not the Yue&Clayton (P = 0.26) index. There were no significant differences between MRSA positive and negative pigs (P = 0.133 and 0.175). OTUs belonging to Firmicutes

  3. Treatment of Methicillin-Resistant Staphylococcus aureus (MRSA) Pneumonia with Ceftaroline Fosamil in a Patient with Inhalational Thermal Injury.

    PubMed

    Faris, Janie; Mynatt, Ryan P; Hall Snyder, Ashley D; Rybak, Michael J

    2015-12-01

    A 48-year-old female, who was found unresponsive and suffered inhalation injury secondary to a house fire, was transferred to our burn center for definitive treatment. Post tracheostomy, the patient became febrile and tachycardic. On hospital day (HD) 5, the patient expressed thick yellow secretions during suctioning and diffuse rhonchi was noted on physical exam. Blood cultures and a culture from the broncheo-alvelolar lavage grew Gram-positive cocci in clusters and the patient was started on empiric vancomycin. Despite aggressive vancomycin dosing (1750 mg intravenously every 6 h), the patient's status continued to deteriorate. The organism was identified as methicillin-resistant Staphylococcus aureus (MRSA) with a vancomycin minimum inhibitory concentration (MIC) of 2 mg/L. Based on the potential for drug-drug interactions with linezolid, the patient was started on ceftaroline fosamil (MIC = 0.5 mg/L) 600 mg intravenously every 8 h with a prolonged 2-h infusion to anticipate suboptimal concentrations secondary to thermal burn injury. Post change in antibiotic therapy, a rapid clinical improvement was observed with the patient becoming afebrile at 48 h after initiation of ceftaroline. The patient completed a total of 14 days of ceftaroline therapy and was subsequently weaned from the ventilator on HD 22 and decannulated 2 days later. To our knowledge, this is the first report of the use of ceftaroline for the treatment of MRSA pneumonia in a patient with thermal injury.

  4. Community-Associated Methicillin-Resistant Staphylococcus aureus Clonal Complex 80 Type IV (CC80-MRSA-IV) Isolated from the Middle East: A Heterogeneous Expanding Clonal Lineage

    PubMed Central

    Harastani, Houda H.; Tokajian, Sima T.

    2014-01-01

    Background The emergence of community-associated methicillin resistant Staphylococcus aureus (CA-MRSA) has caused a change in MRSA epidemiology worldwide. In the Middle East, the persistent spread of CA-MRSA isolates that were associated with multilocus sequence type (MLST) clonal complex 80 and with staphylococcal cassette chromosome mec (SCCmec) type IV (CC80-MRSA-IV), calls for novel approaches for infection control that would limit its spread. Methodology/Principal Findings In this study, the epidemiology of CC80-MRSA-IV was investigated in Jordan and Lebanon retrospectively covering the period from 2000 to 2011. Ninety-four S. aureus isolates, 63 (67%) collected from Lebanon and 31 (33%) collected from Jordan were included in this study. More than half of the isolates (56%) were associated with skin and soft tissue infections (SSTIs), and 73 (78%) were Panton-Valentine Leukocidin (PVL) positive. Majority of the isolates (84%) carried the gene for exofoliative toxin d (etd), 19% had the Toxic Shock Syndrome Toxin-1 gene (tst), and seven isolates from Jordan had a rare combination being positive for both tst and PVL genes. spa typing showed the prevalence of type t044 (85%) and pulsed-field gel electrophoresis (PFGE) recognized 21 different patterns. Antimicrobial susceptibility testing showed the prevalence (36%) of a unique resistant profile, which included resistance to streptomycin, kanamycin, and fusidic acid (SKF profile). Conclusions The genetic diversity among the CC80 isolates observed in this study poses an additional challenge to infection control of CA-MRSA epidemics. CA-MRSA related to ST80 in the Middle East was distinguished in this study from the ones described in other countries. Genetic diversity observed, which may be due to mutations and differences in the antibiotic regimens between countries may have led to the development of heterogeneous strains. Hence, it is difficult to maintain “the European CA-MRSA clone” as a uniform clone and it

  5. A combination of ceftaroline and daptomycin has synergistic and bactericidal activity in vitro against daptomycin nonsusceptible methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Shafiq, Iffat; Bulman, Zackery P; Spitznogle, Sarah L; Osorio, Justin E; Reilly, Irene S; Lesse, Alan J; Parameswaran, Ganapathi I; Mergenhagen, Kari A; Tsuji, Brian T

    2017-05-01

    There is an urgent need to optimize therapeutic options in patients with methicillin-resistant Staphylococcus aureus (MRSA) bacteremia who have failed conventional therapy. Two clinical isolates were obtained from a 68-year-old male with persistent MRSA bacteremia before and after the development of daptomycin nonsusceptibility. The pharmacodynamic activity of monotherapies and combinations of ceftaroline, daptomycin, cefoxitin, nafcillin and vancomycin were evaluated in time-kill experiments versus 10(8) CFU/mL of the pre- and post-daptomycin nonsusceptible MRSA isolates. Cefoxitin, nafcillin and vancomycin alone or in combination with ceftaroline failed to generate prolonged bactericidal activity against the post-daptomycin nonsusceptible isolate whereas a ceftaroline-daptomycin combination resulted in 6, 24 and 48 h log10(CFU/mL) reductions of 3.90, 4.40 and 6.32. Population analysis profiles revealed a daptomycin heteroresistant subpopulation of the pre-daptomycin nonsusceptible MRSA isolate that expanded by >10,000× on daptomycin agar containing 2-16 mg/L in the post-daptomycin nonsusceptible isolate. Daptomycin and ceftaroline combinations may be promising against persistent MRSA bacteremia.

  6. 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.

  7. 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.

  8. 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

  9. 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

  10. 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.

  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. 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

  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. Surveillance of physician-diagnosed skin and soft tissue infections consistent with methicillin-resistant Staphylococcus aureus (MRSA) among Nebraska high school athletes, 2008-2012.

    PubMed

    Buss, Bryan F; Connolly, Susan

    2014-02-01

    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 surveillance was subsequently conducted during 4 school years (2008-2012) to estimate incidence of skin and soft tissue infections (SSTI) consistent with MRSA among student athletes. High school athletic officials completed Internet-based surveys following winter and fall sport seasons. Over 3 school years, incidence estimates per 10,000 athletes decreased substantially from 20.9 (2008-2009) to 11.3 (2010-2011) among football players and from 60.8 (2008-2009) to 28.1 (2010-2011) among wrestlers. Following the 2011-2012 sport seasons, however, incidence estimates increased to 16.6 per 10,000 football players and 43.3 per 10,000 wrestlers. School nurses should support school officials to prioritize prevention and control efforts for SSTI, including MRSA.

  16. 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

  17. 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

  18. Antimicrobial activity of ceftaroline against methicillin-resistant Staphylococcus aureus (MRSA) isolates collected in 2013-2014 at the Geneva University Hospitals.

    PubMed

    Andrey, D O; François, P; Manzano, C; Bonetti, E J; Harbarth, S; Schrenzel, J; Kelley, W L; Renzoni, A

    2017-02-01

    Ceftaroline is a broad-spectrum antibiotic with activity against methicillin-resistant Staphylococcus aureus (MRSA) strains. Ceftaroline susceptibility of an MRSA set archived between 1994 and 2003 in the Geneva University Hospitals detected a high percentage (66 %) of ceftaroline resistance in clonotypes ST228 and ST247 and correlated with mutations in PBP2a. The ceftaroline mechanism of action is based on the inhibition of PBP2a; thus, the identification of PBP2a mutations of recently circulating clonotypes in our institution was investigated. We analyzed ceftaroline susceptibility in MRSA isolates (2013 and 2014) and established that resistant strains correlated with PBP2a mutations and specific clonotypes. Ninety-six MRSA strains were analyzed from independent patients and were isolated from blood cultures (23 %), deep infections (38.5 %), and superficial (skin or wound) infections (38.5 %). This sample showed a ceftaroline minimum inhibitory concentration (MIC) range between 0.25 and 2 μg/ml and disk diameters ranging from 10 to 30 mm, with a majority of strains showing diameters ≥20 mm. Based on the European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints, 76 % (73/96) of isolates showed susceptibility to ceftaroline. Nevertheless, we still observed 24 % (23/96) of resistant isolates (MIC = 2 μg/ml). All resistant isolates were assigned to clonotype ST228 and carried the N146K mutation in PBP2a. Only two ST228 isolates showed ceftaroline susceptibility. The decreasing percentage of ceftaroline-resistant isolates in our hospital can be explained by the decline of ST228 clonotype circulating in our hospital since 2008. We present evidence that ceftaroline is active against recent MRSA strains from our hospital; however, the presence of PBP2a variants in particular clonotypes may affect ceftaroline efficacy.

  19. 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.

  20. Kocurin, the True Structure of PM181104, an Anti-Methicillin-Resistant Staphylococcus aureus (MRSA) Thiazolyl Peptide from the Marine-Derived Bacterium Kocuria palustris

    PubMed Central

    Martín, Jesús; Sousa, Thiciana da S.; Crespo, Gloria; Palomo, Sara; González, Ignacio; Tormo, José R.; de la Cruz, Mercedes; Anderson, Matthew; Hill, Russell T.; Vicente, Francisca; Genilloud, Olga; Reyes, Fernando

    2013-01-01

    A new thiazolyl peptide, kocurin (1), was isolated from culture broths of a marine-derived Kocuria palustris. Its structural elucidation was accomplished using a combination of spectroscopic and chemical methods, including HRMS, extensive 1D and 2D NMR analysis, MS/MS fragmentation, and chemical degradation and Marfey’s analysis of the resulting amino acid residues. The structure herein reported corrects that previously assigned to PM181104 (3). Kocurin displayed activity against methicillin-resistant Staphylococcus aureus (MRSA), with MIC values in the submicromolar range. PMID:23380989

  1. 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

  2. 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

  3. MRSA infection in lower extremity wounds.

    PubMed

    Edris, Bree; Reed, James F

    2008-03-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most frequently isolated bacteria in wound cultures. MRSA has been linked to lengthened wound healing times, an increase in adverse postoperative outcomes, and mortality. This study investigated the incidence of MRSA in lower extremity wounds and examined outcomes associated with MRSA-infected wounds versus non-MRSA-infected wounds. A retrospective study was conducted. Patients with MRSA-infected wounds were compared with those with uninfected wounds in a 1:2 ratio. Demographics, infection, and stay information were collected. Data were analyzed using SPSS 15.0. 51 patients were included (17 with MRSA and 34 without MRSA). Patients with MRSA had increased lengths of stay and a higher incidence of adverse postoperative outcomes compared with non-MRSA patients. An MRSA infection adversely affects a patient's hospital course. Preoperative screening for MRSA and postoperative surveillance should be considered to prevent and eliminate the spread of this virulent bacterium.

  4. 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.

  5. Recurrent MRSA skin infections in atopic dermatitis.

    PubMed

    Ong, Peck Y

    2014-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a frequent cause of recurrent skin and soft tissue infections. For patients with atopic dermatitis, recurrent skin infections with MRSA often lead to eczema exacerbation. There currently is no standard practice in the prevention of recurrent MRSA soft tissue infections in the general and the atopic dermatitis populations. The current article reviews recent data on S aureus decolonization treatments for the prevention of recurrent MRSA soft tissue infections in the community setting.

  6. Comparison of air samples, nasal swabs, ear-skin swabs and environmental dust samples for detection of methicillin-resistant Staphylococcus aureus (MRSA) in pig herds.

    PubMed

    Agersø, Y; Vigre, H; Cavaco, L M; Josefsen, M H

    2014-08-01

    To identify a cost-effective and practical method for detection of methicillin-resistant Staphylococcus aureus (MRSA) in pig herds, the relative sensitivity of four sample types: nasal swabs, ear-skin (skin behind the ears) swabs, environmental dust swabs and air was compared. Moreover, dependency of sensitivity on within-herd prevalence was estimated. spa-typing was applied in order to study strain diversity. The sensitivity of one air sample was equal to the sensitivity of ten pools of five nasal swabs and relatively independent of within-herd prevalence [predicted to be nearly perfect (99%) for within-herd prevalence ⩾25%]. The results indicate that taking swabs of skin behind the ears (ten pools of five) was even more sensitive than taking nasal swabs (ten pools of five) at the herd level and detected significantly more positive samples. spa types t011, t034 and t4208 were observed. In conclusion, MRSA detection by air sampling is easy to perform, reduces costs and analytical time compared to existing methods, and is recommended for initial testing of herds. Ear-skin swab sampling may be more sensitive for MRSA detection than air sampling or nasal swab sampling.

  7. 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.

  8. 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.

  9. Bio-inspired synthesis yields a tricyclic indoline that selectively resensitizes methicillin-resistant Staphylococcus aureus (MRSA) to β-lactam antibiotics

    PubMed Central

    Podoll, Jessica D.; Liu, Yongxiang; Chang, Le; Walls, Shane; Wang, Wei; Wang, Xiang

    2013-01-01

    The continuous emergence of resistant bacteria has become a major worldwide health threat. The current development of new antibacterials has lagged far behind. To discover reagents to fight against resistant bacteria, we initiated a chemical approach by synthesizing and screening a small molecule library, reminiscent of the polycyclic indole alkaloids. Indole alkaloids are a class of structurally diverse natural products, many of which were isolated from plants that have been used as traditional medicine for millennia. Specifically, we adapted an evolutionarily conserved biosynthetic strategy and developed a concise and unified diversity synthesis pathway. Using this pathway, we synthesized 120 polycyclic indolines that contain 26 distinct skeletons and a wide variety of functional groups. A tricyclic indoline, Of1, was discovered to selectively potentiate the activity of β-lactam antibiotics in multidrug-resistant methicillin-resistant Staphylococcus aureus (MRSA), but not in methicillin-sensitive S. aureus. In addition, we found that Of1 itself does not have antiproliferative activity but can resensitize several MRSA strains to the β-lactam antibiotics that are widely used in the clinic, such as an extended-spectrum β-lactam antibiotic amoxicillin/clavulanic acid and a first-generation cephalosporin cefazolin. These data suggest that Of1 is a unique selective resistance-modifying agent for β-lactam antibiotics, and it may be further developed to fight against resistant bacteria in the clinic. PMID:24019472

  10. Proteomic and genomic analysis of methicillin-resistant Staphylococcus aureus (MRSA) exposed to manuka honey in vitro demonstrated down-regulation of virulence markers

    PubMed Central

    Jenkins, Rowena; Burton, Neil; Cooper, Rose

    2014-01-01

    Objectives Methicillin-resistant Staphylococcus aureus (MRSA) is an important pathogen. Its resistance to multiple antibiotics and its prevalence in healthcare establishments make it a serious threat to human health that requires novel interventions. Manuka honey is a broad-spectrum antimicrobial agent that is gaining acceptance in the topical treatment of wounds. Because its mode of action is only partially understood, proteomic and genomic analysis was used to investigate the effects of manuka honey on MRSA at a molecular level. Methods Two-dimensional gel electrophoresis with dual-channel imaging was combined with matrix-assisted laser desorption ionization–time of flight mass spectrometry to determine the identities of differentially expressed proteins. The expression of the corresponding genes was investigated by quantitative PCR. Microarray analysis provided an overview of alterations in gene expression across the MRSA genome. Results Genes with increased expression following exposure to manuka honey were associated with glycolysis, transport and biosynthesis of amino acids, proteins and purines. Those with decreased expression were involved in the tricarboxylic acid cycle, cell division, quorum sensing and virulence. The greatest reductions were seen in genes conferring virulence (sec3, fnb, hlgA, lip and hla) and coincided with a down-regulation of global regulators, such as agr, sae and sarV. A model to illustrate these multiple effects was constructed and implicated glucose, which is one of the major sugars contained in honey. Conclusions A decreased expression of virulence genes in MRSA will impact on its pathogenicity and needs to be investigated in vivo. PMID:24176984

  11. 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.

  12. 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.

  13. Treatment failure and costs in patients with methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infections: A South Texas Ambulatory Research Network (STARNet) study

    PubMed Central

    Labreche, Matthew J.; Lee, Grace C.; Attridge, Russell T.; Mortensen, Eric M.; Koeller, Jim; Du, Liem C.; Nyren, Natalie R.; Treviño, Lucina B.; Treviño, Sylvia B.; Peña, Joel; Mann, Michael W.; Muñoz, Abilio; Marcos, Yolanda; Rocha, Guillermo; Koretsky, Stella; Esparza, Sandra; Finnie, Mitchell; Dallas, Steven D.; Parchman, Michael L.; Frei, Christopher R.

    2013-01-01

    Objective To measure the incidence of treatment failure and associated costs in patients with methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infections (SSTIs). Methods This was a prospective, observational study in 13 primary care clinics. Primary care providers collected clinical data, wound swabs, and 90-day follow-up information. Patients were considered to have “moderate or complicated” SSTIs if they had a lesion ≥ 5 cm in diameter or diabetes mellitus. Treatment failure was evaluated within 90 days of the initial visit. Cost estimates were obtained from federal sources. Results Overall, treatment failure occurred in 21% of patients (n=21/98) at a mean additional cost of $1,933.71 per patient. Treatment failure occurred in 27% of patients in the moderate or complicated group and 11% of patients in the mild or uncomplicated group (p = 0.08). In a subgroup analysis of patients who received I&D, patients with moderate or complicated SSTIs had higher rates of treatment failure than patients with mild or uncomplicated SSTIs (36% vs. 10%; p = 0.04). Conclusions One in five patients presenting to a primary care clinic for a MRSA SSTI will likely require additional interventions as a result of treatment failure at an associated cost of almost $2,000 per patient. Baseline risk stratification and new treatment approaches are needed to reduce treatment failures and costs in the primary care setting. PMID:24004702

  14. 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.

  15. Crystal structure of a Baeyer-Villiger flavin-containing monooxygenase from Staphylococcus aureus MRSA strain MU50.

    PubMed

    Hwang, William C; Xu, Qingping; Wu, Bainan; Godzik, Adam

    2014-08-05

    Flavin-containing Monooxygenase (FMO) catalyzed the oxygenation of broad spectrum of substrates. FMO can also serve as biocatalysts in the Baeyer-Villiger reaction in organic synthesis. Here, we report the high-resolution crystal structure of a Baeyer-Villiger Flavin-containing Monooxygenase (BVFMO) from methicillin- and vancomycin-resistant Staphylococcus aureus strain MU50. The structure of S. aureus FMO should facilitate further development of BVFMO as biocatalysts. A possible role of S. aureus FMO in methicillin and vancomycin resistance is discussed. Proteins 2014. © 2014 Wiley Periodicals, Inc.

  16. 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

  17. 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

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

    PubMed

    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

    2016-03-10

    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.

  19. 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

  20. 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.

  1. Laboratory Evaluation of the BD MAX MRSA Assay

    PubMed Central

    Healer, Vicki; Silbert, Suzane

    2014-01-01

    A comparison between the BD MAX MRSA and Xpert MRSA assays was performed using 239 nares samples. A 97.9% overall agreement between the two molecular assays was observed. The BD MAX MRSA assay proved to be a reliable alternative for a highly automated system to detect methicillin-resistant Staphylococcus aureus (MRSA) in patient nares samples. PMID:24829235

  2. 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

  3. The effect of a cellulose dressing and topical vancomycin on methicillin-resistant Staphylococcus aureus (MRSA) and Gram-positive organisms in chronic wounds: a case series.

    PubMed

    Albaugh, Karen W; Biely, Scott A; Cavorsi, Joseph P

    2013-05-01

    High levels of persistent bacteria may contribute to wound chronicity and delayed healing. A prospective study was conducted to: 1) evaluate the effect of applying vancomycin topically on appropriately cultured chronic lower leg wounds, specifically methicillin-resistant Staphylococcus aureus (MRSA) and Gram-positive bacteria, and 2) evaluate its effect in combination with a cellulose dressing on healing. Twenty-three (23) outpatients (11 men, 12 women, average age 65 years [range 39-89 years]) with lower extremity wounds (15 venous ulcers, six chronic open wounds with a history of diabetes, and two chronic open trauma wounds) averaging 43.58 weeks' (range 5-121 weeks) duration and swab-cultured positive for MRSA or Gram-positive bacteria were provided 1 g vancomycin delivered by a cellulose dressing and changed every 72 hours. Patients served as their own control, and all wounds were debrided once a week. Wound surface area and bacterial and exudate levels were recorded weekly during the 3-week pretreatment period and compared to 3-week treatment period levels. Patients were followed until healed. Mean change in wound surface area was +14.5% (SD 71.91) per week before and -24.6% (SD 13.59) during the vancomycin treatment period (P = 0.014), average exudate levels decreased from 2.75 (range 1-4) to 1.81 (range 0-3) (P = 0.016), and the number of patients with positive wound cultures for MRSA or Gram-positive bacteria decreased from 23 to four after the 3-week study period. All wounds healed after an average of 8.18 weeks (SD 4.76, range 2-17 weeks). The results of this study suggest topical vancomycin applied using a dressing that retains moisture reduces wound bacterial load and may facilitate healing. Randomized, controlled clinical studies to evaluate the effectiveness and efficacy of this treatment modality and explore the relationship between wound culture results and healing are warranted.

  4. Two-dimensional analysis of exoproteins of methicillin-resistant Staphylococcus aureus (MRSA) for possible epidemiological applications.

    PubMed

    Nakano, Miyo; Kawano, Yasushi; Kawagish, Mika; Hasegawa, Tadao; Iinuma, Yoshitsugu; Oht, Michio

    2002-01-01

    We applied two-dimensional gel electrophoresis (2-DE) to the total exoproteins secreted from pathogenic MRSA strains and identified major protein spots by N-terminal amino acid sequence analysis. In approximately 300 to 500 spots visualized on each gel, various exoproteins and cell-associated proteins were identified and their sites on the gels confirmed for construction of a reference map. Major exotoxins such as enterotoxins SEA, SEB, and SEC,, toxic shock syndrome toxin-1 (TSST-1), and hemolysins were distributed in the region of pI 6.8 to 8.1 and MW 21 to 35 kDa. Although the differences between calculated and observed values of pI and MW were relatively small in each exoprotein, those of several proteins including alpha-hemolysin and SEB were considerably deviated from the positions of the expected values. Some exoproteins were detected as multiple spots. These included beta-hemolysin, enterotoxins SEA, SEB, and SEC3, glutamic acid-specific endopeptidase, glycerophosphoryl diester phosphodiesterase and triacylglycerol lipase. The multiple spots of these exoproteins may be generated by the action of own proteases. Certain similarities of 2-DE patterns among strains belonging to the same coagulase types were observed. On the basis of 2-DE image analysis, coagulase type II strains secreted somewhat larger amounts of SEB and SEC3 as well as TSST-1 than the strains belonging to other coagulase types. Taken together, 2-DE analysis of exoproteins is applicable to epidemiological studies for MRSA, as compared with pulsed field gel electrophoresis of restricted chromosomal DNA.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. Classical β-Lactamase Inhibitors Potentiate the Activity of Daptomycin against Methicillin-Resistant Staphylococcus aureus and Colistin against Acinetobacter baumannii

    PubMed Central

    Rose, Warren; Berti, Andrew; Olson, Joshua; Munguia, Jason; Nonejuie, Poochit; Sakoulas, Eleanna; Rybak, Michael J.; Pogliano, Joseph; Nizet, Victor

    2016-01-01

    ABSTRACT We asked whether beta-lactamase inhibitors (BLIs) increased the activity of daptomycin (DAP) against methicillin-resistant Staphylococcus aureus (MRSA), the peptide antibiotic colistin (COL) against the emerging Gram-negative nosocomial pathogen Acinetobacter baumannii, and the human host defense peptide cathelicidin LL37 against either pathogen. DAP and LL37 kill curves were performed with or without BLIs against MRSA, vancomycin-intermediate S. aureus (VISA), and heterogeneous VISA (hVISA). COL and LL37 kill curves were performed against A. baumannii. Boron-dipyrromethene (BODIPY)-labeled DAP binding to MRSA grown with the BLI tazobactam (TAZ) was assessed microscopically. The combination of COL plus TAZ was studied in a murine model of A. baumannii pneumonia. TAZ alone lacked in vitro activity against MRSA or A. baumannii. The addition of TAZ to DAP resulted in a 2- to 5-log10 reduction in recoverable MRSA CFU at 24 h compared to the recoverable CFU with DAP alone. TAZ plus COL showed synergy by kill curves for 4 of 5 strains of A. baumannii tested. Growth with 20 mg/liter TAZ resulted in 2- to 2.5-fold increases in the intensity of BODIPY-DAP binding to MRSA and hVISA strains. TAZ significantly increased the killing of MRSA and A. baumannii by LL37 in vitro. TAZ increased the activity of COL in a murine model of A. baumannii pneumonia. Classical BLIs demonstrate synergy with peptide antibiotics. Since BLIs have scant antimicrobial activity on their own and are thus not expected to increase selective pressure toward antibiotic resistance, their use in combination with peptide antibiotics warrants further study. PMID:27872080

  11. 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.

  12. 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.

  13. MRSA - Multiple Languages: MedlinePlus

    MedlinePlus

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

  14. 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...

  15. 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 ...

  16. Why tackling MRSA needs a comprehensive approach.

    PubMed

    Fairclough, Sarah J

    Methicillin-resistant Staphylococcus aureus (MRSA) causes a fifth of hospital-acquired infections and many other bacteria now show increased resistance to antibacterials. In some parts of the world, community-associated MRSA infections cause a growing number of infections (Fridkin et al, 2005). Attempts to control the spread of MRSA rely on several factors: detecting and isolating infected or colonized patients (cordon sanitaire), rational antibiotic prescribing, hand hygiene and cleanliness. Nurses are key to implementing all of these measures. This article examines the epidemiology of MRSA, as exemplifying an antibiotic-resistant bacterium, and reviews the evidence for the various interventions. A single measure alone is unlikely to eradicate MRSA from either hospitals or the community; indeed, eradicating MRSA is probably impossible. However, a comprehensive approach, including, in particular, good hand hygiene, could reduce the morbidity and mortality arising from MRSA and other hospital-acquired infections.

  17. Cost analysis of a hospital-wide selective screening programme for methicillin-resistant Staphylococcus aureus (MRSA) carriers in the context of diagnosis related groups (DRG) payment.

    PubMed

    Wernitz, M H; Keck, S; Swidsinski, S; Schulz, S; Veit, S K

    2005-06-01

    The costs of a hospital-wide selective screening programme were analysed for a period of 19 months. During this time, 539 inpatients were screened, of whom 111 were MRSA-positive. Based on microbiological costs (staff and materials) and the costs of preventive contact isolation for 2 days until microbiological results were available (including material costs for medical consumable goods and the costs of additional nursing time), a total of 26,241.51 Euro was spent for the 539 patients screened. Based on cost units, the costs were 39.96 Euro for a patient found to be MRSA-negative and 82.33 Euro for a patient found to be MRSA-positive. Under the prospective diagnosis related groups (DRG) payment system in Germany, the costs of a prolonged hospital stay resulting from a hospital-acquired MRSA infection (HA-MRSA-I) are not reimbursed adequately by revenues, with a calculated average cost-revenue loss/patient with HA-MRSA-I of 5705.75 Euro. The screening programme was able to prevent 48% of predicted HA-MRSA-Is (35.2 patients with infection), thereby saving a predicted 200,782.73 Euro. After subtracting the screening costs, there was a net saving of 110,236.56 Euro annually. A sensitivity analysis of the break-even points for different screening frequencies and different MRSA incidence rates indicated that the screening programme became cost-effective at a low MRSA incidence rate, meaning that it can be recommended for most hospitals with an MRSA problem.

  18. 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

  19. Use of antibiotics in animal agriculture & emergence of methicillin-resistant Staphylococcus aureus (MRSA) clones: need to assess the impact on public health.

    PubMed

    Mehndiratta, P L; Bhalla, P

    2014-09-01

    Widespread use of antibiotics in human, veterinary medicine and agricultural settings has played a significant role in the emergence of resistant MRSA clones due to selection pressure. MRSA has now become established in human population as well as in various animal species. An animal associated clone, MRSA ST 398 has been reported from animal foods and also from human infections in the community as well as from the health care associated infections. Clonal relationship between strains of animal and human origins are indicators of interspecies transmission of clones. Spread of these organisms may pose a great impact on public health if animal associated strains enter into the community and health care settings. Surveillance is important to correlate the genetic changes associated with their epidemiological shift and expansion to predict its impact on public health. Strict regulations on the use of antibiotics in humans as well as in animal food production are required to control the emergence of drug resistant clones. t0 his article reviews the information available on the role of antibiotics in emergence of MRSA strains, their epidemiological shift between humans and animals and its impact on the public health.

  20. MRSA Screening

    MedlinePlus

    ... Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising ... aureus Screening Related tests: Wound Culture All content on Lab Tests Online has been ...

  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. Variation in MRSA identification results from different generations of Xpert MRSA real-time PCR testing kits from nasal swabs.

    PubMed

    Rabaan, Ali A; Bazzi, Ali M

    2017-02-06

    GeneXpert MRSA kits (Cepheid) are based on a multiplex, real-time PCR method for methicillin-resistant Staphylococcus aureus (MRSA) detection, with primers to detect each SCCmec type and the chromosomal orfX-SCCmec junction. Modifications in recent kit versions were proposed to help overcome false-positive issues in earlier kit versions. The main objective of this study was to determine whether use of any version of the GeneXpert MRSA multiplex, real-time PCR kits yielded higher than expected MRSA+ results. We also estimated the level of MRSA in our healthcare facility as a proportion of total S. aureus between 2010 and 2015. We examined results from five generations of the kits used between 2008 and 2015. Results were from nasal swab samples from 16,431 patients in the Johns Hopkins Aramco Healthcare facility in Saudi Arabia. The percentage of isolates scored as MRSA+ for the original Xpert MRSA kit was 18.57%, compared to 6.93±1.12% (mean±SD) for the other four kits. The Xpert MRSA-SA Nasal kit yielded 6.48% Invalid results, compared to 0.73±0.28% for the other four kits. The succeeding Xpert MRSA-SA Nasal G3 and Xpert MRSA-SA Nasal Complete G3 kits yielded Invalid results rates of 0.29% and 1.04% respectively. Levels of MRSA-positive isolates as a percentage of total S. aureus-containing samples ranged between 19.81% and 26.74%. In conclusion, the original Xpert MRSA kit yielded higher than expected rates of MRSA+. Issues with over-estimation of MRSA+ and/or numerous Invalid results have been overcome in the most recent modified kits.

  3. 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.

  4. Synergistic Interaction of Methanol Extract from Canarium odontophyllum Miq. Leaf in Combination with Oxacillin against Methicillin-Resistant Staphylococcus aureus (MRSA) ATCC 33591

    PubMed Central

    Sandra, Vimashiinee

    2016-01-01

    Canarium odontophyllum (CO) Miq. has been considered as one of the most sought-after plant species in Sarawak, Malaysia, due to its nutritional and pharmacological benefits. This study aimed to evaluate the pharmacodynamic interaction of crude methanol and acetone extracts from CO leaves in combination with oxacillin, vancomycin, and linezolid, respectively, against MRSA ATCC 33591 as preliminary study has reported its potential antistaphylococcal activity. The broth microdilution assay revealed that both methanol and acetone extracts were bactericidal with Minimum Inhibitory Concentration (MIC) of 312.5 μg/mL and 156.25 μg/mL and Minimum Bactericidal Concentration (MBC) of 625 μg/mL and 312.5 μg/mL, respectively. Fractional Inhibitory Concentration (FIC) indices were obtained via the chequerboard dilution assay where methanol extract-oxacillin, acetone extract-oxacillin, methanol extract-linezolid, and acetone extract-linezolid combinations exhibited synergism (FIC index ≤ 0.5). The synergistic action of the methanol extract-oxacillin combination was verified by time-kill analysis where bactericidal effect was observed at concentration of 1/8 × MIC of both compounds at 9.6 h compared to oxacillin alone. As such, these findings postulated that both extracts exert their anti-MRSA mechanism of action similar to that of vancomycin and provide evidence that the leaves of C. odontophyllum have the potential to be developed into antistaphylococcal agents. PMID:27006659

  5. 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...

  6. 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

  7. Phenol soluble modulin (PSM) variants of community-associated methicillin-resistant Staphylococcus aureus (MRSA) captured using mass spectrometry-based molecular networking.

    PubMed

    Gonzalez, David J; Vuong, Lisa; Gonzalez, Isaiah S; Keller, Nadia; McGrosso, Dominic; Hwang, John H; Hung, Jun; Zinkernagel, Annelies; Dixon, Jack E; Dorrestein, Pieter C; Nizet, Victor

    2014-05-01

    Molecular genetic analysis indicates that the problematic human bacterial pathogen methicillin-resistant Staphylococcus aureus possesses more than 2000 open reading frames in its genome. This number of potential gene products, coupled with intrinsic mechanisms of posttranslational modification, endows methicillin-resistant Staphylococcus aureus with a highly complex biochemical repertoire. Recent proteomic and metabolomic advances have provided methodologies to better understand and characterize the biosynthetic factors released by microbial organisms. Here, the emerging tool of mass spectrometry-based molecular networking was used to visualize and map the repertoire of biosynthetic factors produced by a community-associated methicillin-resistant Staphylococcus aureus strain representative of the epidemic USA300 clone. In particular, the study focused on elucidating the complexity of the recently discovered phenol soluble modulin family of peptides when placed under various antibiotic treatment stresses. Novel PSM truncated variant peptides were captured, and the type of variants that were clustered by the molecular networks platform changed in response to the different antibiotic treatment conditions. After discovery, a group of the peptides were selected for functional analysis in vitro. The peptides displayed bioactive properties including the ability to induce proinflammatory responses in human THP-1 monocytes. Additionally, the tested peptides did not display antimicrobial activity as previously reported for other phenol soluble modulin truncated variants. Our findings reveal that the PSM family of peptides are quite structurally diverse, and suggest a single phenol soluble modulin parent peptide can functionally spawn differential bioactivities in response to various external stimuli.

  8. LA-MRSA CC398 differ from classical community acquired-MRSA and hospital acquired-MRSA lineages: functional analysis of infection and colonization processes.

    PubMed

    Ballhausen, Britta; Jung, Philipp; Kriegeskorte, André; Makgotlho, Phuti Edward; Ruffing, Ulla; von Müller, Lutz; Köck, Robin; Peters, Georg; Herrmann, Mathias; Ziebuhr, Wilma; Becker, Karsten; Bischoff, Markus

    2014-10-01

    Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) of the clonal complex (CC) 398 became primarily known as colonizers of livestock animals. In the past few years, they have been increasingly introduced into hospitals with subsequent emergence of human infections. However, the (re-)adaptation to the human host is only incompletely understood. This study aimed to assess virulence properties of LA-MRSA CC398 by functional modeling of infection and colonization processes. A selection of 15 human LA-MRSA CC398 isolates and 11 pig-colonizing isolates were characterized regarding their virulence capacities and compared with human isolates of hospital-acquired (HA)-MRSA (CC5, CC22 and CC45) and community-associated (CA)-MRSA (CC8, CC30 and CC80) clonal lineages. Our investigations demonstrated that LA-MRSA CC398 adhered less efficient to human cells and human/bovine plasma fibronectin than CA-MRSA and HA-MRSA isolates. In contrast, the LA-MRSA CC398 isolates revealed a high cytotoxic potential comparable to certain CA-MRSA. Comparing the most prevalent LA-MRSA CC398 spa types (t011, t034, t108), isolates associated with spa t108 showed an increased adhesive and invasive potential paired with an increased ability to evade phagocytosis. The results underline both the pathogenic potential of LA-MRSA in general and the heterogeneity within the CC398 clade regarding the virulence characteristics of CC398 subpopulations. Assuming an ongoing (re-)adaptation to the human host combined with a huge reservoir of LA-MRSA CC398 in livestock and constant zoonotic transmission, the LA-MRSA CC398 lineage has the potential to pose a serious threat to human health.

  9. Methicillin-resistant Staphylococcus aureus: the superbug.

    PubMed

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

    2010-10-01

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

  10. Antibiotic selection for MRSA: case presentations and review of the literature.

    PubMed

    Hanson, Matthew R; Chung, Christina L

    2009-03-01

    Infection with methicillin-resistant Staphylococcus aureus (MRSA) is a growing presence in both the community and hospital settings. Initially, MRSA was a difficult to treat infection isolated to hospitalized patients. With the introduction of vancomycin and other newer antibiotics, successful treatment of nosocomial, or hospital-acquired MRSA (HA-MRSA) has become commonplace. More recently, MRSA has evolved independently in each community. These community-acquired MRSA (CA-MRSA) strains initially had more limited resistance profiles, but selective pressures have broadened the resistance in many areas. Given the evolution in resistance among MRSA isolates, choosing an appropriate antibiotic therapy is challenging. Here the authors present 3 cases of HA- and CA-MRSA from an inner-city, tertiary care center and review recent literature with regards to antibiotic selection and administration.

  11. PVL-positive MRSA in Austria.

    PubMed

    Krziwanek, K; Luger, C; Sammer, B; Stumvoll, S; Stammler, M; Metz-Gercek, S; Mittermayer, H

    2007-12-01

    The objective of this study was to present, for the first time, an overview of the existing Panton-Valentine leukocidin (PVL)-positive methicillin-resistant Staphylococcus aureus (MRSA) strains in Austria and to compare the situation with that found in other countries. Between 2001 and 2006 we analysed 1150 MRSA isolates - from infections as well as from colonisation - for the presence of PVL genes. The most common multilocus sequence types of the 94 PVL-positive MRSA strains were ST8, ST152, ST30, ST80, and ST5; the ST22, and ST777 sequences were also detected. During 2005 and 2006, 3.7-7.7% of the isolates were PVL-positive. The age distribution of the patients revealed that nosocomial MRSA mainly occurs in elderly people, whereas PVL-positive MRSA mainly appears in younger people. We observed a relatively high prevalence of PVL-positive isolates. Several MRSA clones containing the PVL genes are spreading throughout Austria, including two strains not yet widespread in Western Europe.

  12. MRSA in Austria--an overview.

    PubMed

    Krziwanek, K; Luger, C; Sammer, B; Stumvoll, S; Stammler, M; Sagel, U; Witte, W; Mittermayer, H

    2008-03-01

    The aim of this study was to provide an overview of predominant and sporadic methicillin-resistant Staphylococcus aureus (MRSA) strains in large regions of Austria, and to compare the results with those from other European countries. In total, 1439 MRSA isolates, collected routinely between January 1996 and June 2006 from five Austrian federal provinces, were investigated. The isolates were confirmed as MRSA using mecA/femA multiplex PCR assays. Genes encoding Panton-Valentine leukocidin (PVL), which are characteristic of community-acquired MRSA, were also detected by PCR. Subtyping was performed using SmaI macrorestriction digestion of genomic DNA, followed by pulsed-field gel electrophoresis (PFGE) and cluster analysis. Isolates that could not be assigned to clusters were further analysed by spa typing and/or multilocus sequence typing. The predominant clones detected in Austria were ST228 (southern German epidemic clone), ST5 (Rhine-Hessen MRSA), the ST8 Austrian clone and CC8/ST8. Whereas the frequencies of lineages corresponding to ST247, ST45 and ST22 remained comparably low, an increase in the frequency of lineages corresponding to ST5 and to ST228 was recorded. Overall, 20 different MRSA types and 321 subtypes were recognised according to PFGE analysis. The prevalence of different strains varied considerably in the different Austrian regions. When compared to other European countries, the situation in Austria was most similar to that found in Germany.

  13. 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

  14. The "hospital superbug": social representations of MRSA.

    PubMed

    Washer, Peter; Joffe, Helene

    2006-10-01

    The so-called 'hospital superbug' methcillin-resistant Staphylococcus aureus (MRSA) became a topic of media and political concern in Britain from the middle of the 1990s. It was increasingly politicised in the period leading up to the British General Election of 2005. This study examines the meanings of MRSA that circulate in Britain by analysing newspaper coverage of the disease over the 10-year period 1995-2005. It utilises social representations theory and contextualises MRSA within existing research on representations of emerging infectious diseases (EIDs). A key pattern in the representation of EIDs is to externalise the threat they pose by linking the origin, risk and blame to 'the other' of those who represent them. It is in this light that this study investigates who and what MRSA is associated with and the impact that these associations have on levels of alarm and blame. Key findings are that MRSA is represented as a potentially lethal 'superbug', marking the end of a 'golden age of medicine' in which the story of the discovery of antibiotics has played such a key role. Furthermore, MRSA is constructed around an "it could be you/me" set of assumptions by way of the plethora of human interest stories that dominate the coverage. Finally, the blame for MRSA focuses not on its genesis, but rather on why it spreads. This is attributed to poor hygiene in hospitals, which is ultimately caused by mismanagement of the National Health Service and erosion of the authority and morality symbolised by the 'matron' role. This constellation of meanings informs a somewhat different pattern of response to MRSA when compared to many past EIDs.

  15. Antimicrobial activity of a new synthetic peptide loaded in polylactic acid or poly(lactic-co-glycolic) acid nanoparticles against Pseudomonas aeruginosa, Escherichia coli O157:H7 and methicillin resistant Staphylococcus aureus (MRSA).

    PubMed

    Cruz, J; Flórez, J; Torres, R; Urquiza, M; Gutiérrez, J A; Guzmán, F; Ortiz, C C

    2017-03-01

    Nanocarrier systems are currently being developed for peptide, protein and gene delivery to protect them in the blood circulation and in the gastrointestinal tract. Polylactic acid (PLA) and poly(lactic-co-glycolic) acid (PLGA) nanoparticles loaded with a new antimicrobial GIBIM-P5S9K peptide were obtained by the double emulsion solvent extraction/evaporation method. PLA- and PLGA-NPs were spherical with sizes between 300 and 400 nm for PLA and 200 and 300 nm for PLGA and <0.3 polydispersity index as determined by dynamic light scattering and scanning electron microscopy), having the zeta potential of >20 mV. The peptide-loading efficiency of PLA-NP and PLGA-NPs was 75% and 55%, respectively. PLA- and PLGA-NPs released around 50% of this peptide over 8 h. In 10% human sera the size of peptide loaded PLA- and PLGA-NPs increased between 25.2% and 39.3%, the PDI changed from 3.2 to 5.1 and the surface charge from -7.15 to 14.6 mV. Both peptide loaded PLA- and PLGA-NPs at 0.5 μM peptide concentration inhibited the growth of Escherichia coli O157:H7 (E. coli O157:H7), methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas. aeruginosa (P. aeruginosa). In contrast, free peptide inhibited at 10 μM but did not inhibit at 0.5 and 1 μM. These PLA- and PLGA-NPs presented <10% hemolysis indicating that they are hemocompatible and promising for delivery and protection system of GIBIM-P5S9K peptide.

  16. Antimicrobial activity of a new synthetic peptide loaded in polylactic acid or poly(lactic-co-glycolic) acid nanoparticles against Pseudomonas aeruginosa, Escherichia coli O157:H7 and methicillin resistant Staphylococcus aureus (MRSA)

    NASA Astrophysics Data System (ADS)

    Cruz, J.; Flórez, J.; Torres, R.; Urquiza, M.; Gutiérrez, J. A.; Guzmán, F.; Ortiz, C. C.

    2017-03-01

    Nanocarrier systems are currently being developed for peptide, protein and gene delivery to protect them in the blood circulation and in the gastrointestinal tract. Polylactic acid (PLA) and poly(lactic-co-glycolic) acid (PLGA) nanoparticles loaded with a new antimicrobial GIBIM-P5S9K peptide were obtained by the double emulsion solvent extraction/evaporation method. PLA- and PLGA-NPs were spherical with sizes between 300 and 400 nm for PLA and 200 and 300 nm for PLGA and <0.3 polydispersity index as determined by dynamic light scattering and scanning electron microscopy), having the zeta potential of >20 mV. The peptide-loading efficiency of PLA-NP and PLGA-NPs was 75% and 55%, respectively. PLA- and PLGA-NPs released around 50% of this peptide over 8 h. In 10% human sera the size of peptide loaded PLA- and PLGA-NPs increased between 25.2% and 39.3%, the PDI changed from 3.2 to 5.1 and the surface charge from ‑7.15 to 14.6 mV. Both peptide loaded PLA- and PLGA-NPs at 0.5 μM peptide concentration inhibited the growth of Escherichia coli O157:H7 (E. coli O157:H7), methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas. aeruginosa (P. aeruginosa). In contrast, free peptide inhibited at 10 μM but did not inhibit at 0.5 and 1 μM. These PLA- and PLGA-NPs presented <10% hemolysis indicating that they are hemocompatible and promising for delivery and protection system of GIBIM-P5S9K peptide.

  17. DOES THE NOSE KNOW? AN UPDATE ON MRSA DECOLONIZATION STRATEGIES

    PubMed Central

    Abad, C.L.; Pulia, M. S.; Safdar, N.

    2014-01-01

    Colonization with methicillin-resistant Staphylococcus aureus (MRSA) is an important step in the pathogenesis of active infection and is a key factor in the epidemiology of MRSA infection. Decolonization of patients found to have MRSA carriage may be of value in certain patient populations, especially those undergoing elective surgery. However, the most commonly used agent for decolonization, mupirocin, comes with a considerable risk of resistance if widely employed. Recent studies of other novel agents for decolonization show promise but further research is necessary. This review focuses on the pathogenesis from MRSA colonization to infection, identifies the risk factors for colonization, and summarizes decolonization strategies, including novel approaches that may ave a role in decreasing MRSA disease burden. PMID:24150839

  18. 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.

  19. 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…

  20. Methicillin-Resistant Staphylococcus aureus ST398 from Human Patients, Upper Austria

    PubMed Central

    Metz-Gercek, Sigrid; Mittermayer, Helmut

    2009-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) clonal type ST398 is usually associated with animals. We examined 1,098 confirmed MRSA samples from human patients and found that 21 were MRSA ST398. Most (16) patients were farmers. Increasing prevalence from 1.3% (2006) to 2.5% (2008) shows emergence of MRSA ST398 in humans in Austria. PMID:19402964

  1. Methicillin-Resistant Staphylococcus aureus ST398 from human patients, upper Austria.

    PubMed

    Krziwanek, Karina; Metz-Gercek, Sigrid; Mittermayer, Helmut

    2009-05-01

    Methicillin-resistant Staphylococcus aureus (MRSA) clonal type ST398 is usually associated with animals. We examined 1,098 confirmed MRSA samples from human patients and found that 21 were MRSA ST398. Most (16) patients were farmers. Increasing prevalence from 1.3% (2006) to 2.5% (2008) shows emergence of MRSA ST398 in humans in Austria.

  2. Evolving incidence of MRSA in urban hand infections.

    PubMed

    Fowler, John R; Greenhill, Dustin; Schaffer, Alyssa A; Thoder, Joseph J; Ilyas, Asif M

    2013-06-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is the most commonly cultured bacteria in hand infections. Understanding the most common bacteria involved in hand infections allows appropriate and efficient administration of antibiotics. Delay in treatment may lead to increased morbidity, including stiffness, contracture, and amputation. The purposes of this study are to determine whether the incidence of MRSA in culture-positive hand infections continues to increase and whether MRSA is a risk factor for increased length of stay. Electronic medical records were queried to identify patients admitted to a large, academic urban medical center with the diagnosis of a hand infection between January 1, 2005, and December 31, 2009. Methicillin-resistant S aureus accounted for 220 of the positive cultures over the 5-year study period. Polymicrobial infection represented 81 positive cultures, and MRSA was only present in 10 of these cases. Patients with MRSA were found to have a mean length of hospital stay of 4.1 days compared with 4.5 days in non-MRSA infections. Understanding the most common bacteria involved in hand infections allows appropriate and efficient administration of antibiotics. Methicillin-resistant S aureus is the most commonly cultured bacteria in the hand. However, polymicrobial infections have become increasingly more common. Although incidences of polymicrobial infections increased over the study period in this series, clinical judgment should be exercised before initiating broad-spectrum antibiotic coverage.

  3. 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.

  4. MRSA in Conventional and Alternative Retail Pork Products

    PubMed Central

    O'Brien, Ashley M.; Hanson, Blake M.; Farina, Sarah A.; Wu, James Y.; Simmering, Jacob E.; Wardyn, Shylo E.; Forshey, Brett M.; Kulick, Marie E.; Wallinga, David B.; Smith, Tara C.

    2012-01-01

    In order to examine the prevalence of Staphylococcus aureus on retail pork, three hundred ninety-five pork samples were collected from a total of 36 stores in Iowa, Minnesota, and New Jersey. S. aureus was isolated from 256 samples (64.8%, 95% confidence interval [CI] 59.9%–69.5%). S. aureus was isolated from 67.3% (202/300) of conventional pork samples and from 56.8% (54/95) of alternative pork samples (labeled “raised without antibiotics” or “raised without antibiotic growth promotants”). Two hundred and thirty samples (58.2%, 95% CI 53.2%–63.1%) were found to carry methicillin-sensitive S. aureus (MSSA). MSSA was isolated from 61.0% (183/300) of conventional samples and from 49.5% (47/95) of alternative samples. Twenty-six pork samples (6.6%, 95% CI 4.3%–9.5%) carried methicillin-resistant S. aureus (MRSA). No statistically significant differences were observed for the prevalence of S. aureus in general, or MSSA or MRSA specifically, when comparing pork products from conventionally raised swine and swine raised without antibiotics, a finding that contrasts with a prior study from the Netherlands examining both conventional and “biologic” meat products. In our study spa types associated with “livestock-associated” ST398 (t034, t011) were found in 26.9% of the MRSA isolates, while 46.2% were spa types t002 and t008—common human types of MRSA that also have been found in live swine. The study represents the largest sampling of raw meat products for MRSA contamination to date in the U.S. MRSA prevalence on pork products was higher than in previous U.S.-conducted studies, although similar to that in Canadian studies. PMID:22276147

  5. 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

  6. Overview: Methicillin-Resistant Staphylococcus aureus (MRSA)

    MedlinePlus

    ... Letter Create a Resource Sharing Plan Use the PHS Assignment Request Form Research with Special Considerations Human ... Laboratory of Immunoregulation Previous Directors John R. LaMontagne, Ph.D. Richard M. Krause, M.D. Dorland J. ...

  7. Methicillin-Resistant Staphylococcus aureus (MRSA) Diagnosis

    MedlinePlus

    ... Helps Researchers Explore Microbial Genomic Data Biological Materials Biological Material Repositories HIV/AIDS Specimen Repository Guidance for Accessing Network Samples DAIDS VAX004 Clinical Trial Specimens Scientific Priorities ...

  8. Methicillin-Resistant Staphylococcus aureus (MRSA) Treatment

    MedlinePlus

    ... Helps Researchers Explore Microbial Genomic Data Biological Materials Biological Material Repositories HIV/AIDS Specimen Repository Guidance for Accessing Network Samples DAIDS VAX004 Clinical Trial Specimens Scientific Priorities ...

  9. Clinical inquiries. When should you suspect community-acquired MRSA? How should you treat it?

    PubMed

    May, Todd J; Safranek, Sarah

    2009-05-01

    There are no clinical or epidemiologic features that will help you to clearly distinguish community-acquired methicillin-resistant Staphylococcus aureus infections (CA-MRSA) from methicillin-sensitive (CA-MSSA) infections. Incision and drainage is the primary therapy for purulent skin and soft tissue infections. There are inadequate data evaluating the role of oral antibiotics for MRSA.

  10. A Neonatal Murine Model of MRSA Pneumonia

    PubMed Central

    Shrestha, Bishwas; Siefker, David; Patel, Vivek S.; Yadav, Nikki; Jaligama, Sridhar; Cormier, Stephania A.

    2017-01-01

    Pneumonia due to methicillin-resistant Staphylococcus aureus (MRSA) is a significant cause of morbidity and mortality in infants particularly following lower respiratory tract viral infections such as Respiratory Syncytial Virus (RSV). However, the mechanisms by which co-infection of infants by MRSA and RSV cause increased lung pathology are unknown. Because the infant immune system is qualitatively and quantitatively different from adults we developed a model of infant MRSA pneumonia which will allow us to investigate the effects of RSV co-infection on disease severity. We infected neonatal and adult mice with increasing doses of MRSA and demonstrate that neonatal mice have delayed kinetics in clearing the bacteria in comparison to adult mice. There were differences in recruitment of immune cells into the lung following infection. Adult mice exhibited an increase in neutrophil recruitment that coincided with reduced bacterial titers followed by an increase in macrophages. Neonatal mice, however, exhibited an early increase in neutrophils that did not persist despite continued presence of the bacteria. Unlike the adult mice, neonatal mice failed to exhibit an increase in macrophages. Neonates exhibited a decrease in phagocytosis of MRSA suggesting that the decrease in clearance was partially due to deficient phagocytosis of the bacteria. Both neonates and adults responded with an increase in pro-inflammatory cytokines following infection. However, in contrast to the adult mice, neonates did not express constitutive levels of the anti-microbial peptide Reg3γ in the lung. Infection of neonates did not stimulate expression of the co-stimulatory molecule CD86 by dendritic cells and neonates exhibited a diminished T cell response compared to adult mice. Overall, we have developed a neonatal model of MRSA pneumonia that displays a similar delay in bacterial clearance as is observed in the neonatal intensive care unit and will be useful for performing co

  11. 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...

  12. 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.

  13. 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.

  14. USA300 genotype community-associated methicillin-resistant Staphylococcus aureus as a cause of surgical site infections.

    PubMed

    Patel, Mukesh; Kumar, Ritu A; Stamm, Alan M; Hoesley, Craig J; Moser, Stephen A; Waites, Ken B

    2007-10-01

    Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) strains are increasingly recovered from nosocomial settings. We conducted a retrospective study of surgical site infections (SSI) during 2004 and 2005 to determine the prevalence of CA-MRSA; 57% of MRSA strains tested belonged to the USA300 genotype. CA-MRSA has become a prominent cause of SSI at our institution.

  15. 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

  16. A Cross-Sectional Study of Colonization Rates with Methicillin-Resistant Staphylococcus aureus (MRSA) and Extended-Spectrum Beta-Lactamase (ESBL) and Carbapenemase-Producing Enterobacteriaceae in Four Swiss Refugee Centres

    PubMed Central

    Pop, Roxana; Zillig, Daniela; Schibli, Urs; Bassetti, Stefano; Meinel, Dominik; Egli, Adrian

    2017-01-01

    Background The recent crisis of refugees seeking asylum in European countries challenges public health on many levels. Most refugees currently arrive from Syria, Afghanistan, or Eritrea. Data about multidrug resistant bacteria (MDR) prevalence are not present for these countries. However, when entering the European heath care systems, data about colonisation rates regarding highly resistant bacterial pathogens are important. Methods We performed a cross-sectional screening in four Swiss refugee centres to determine the colonization rates for MRSA and ESBL- and carbapenemase-producing Enterobacteriaceae. We used pharyngeal, nasal, and inguinal swabs for MRSA and rectal swabs and urine for ESBL and carbapenemase screening using standard microbiological procedures. Whole genome sequencing (WGS) was used to determine the relatedness of MRSA isolates with high resolution due to a suspected outbreak. Results 41/261(15.7%) refugees were colonized with MRSA. No differences regarding the country of origin were observed. However, in a single centre significantly more were colonized, which was confirmed to be a recent local outbreak. 57/241 (23.7%) refugees were colonized with ESBL with significantly higher colonisation in persons originating from the Middle East (35.1%, p<0.001). No carbapenemase producers were detected. Conclusion The colonisation rate of the refugees was about 10 times higher for MRSA and 2–5 times higher for ESBL compared to the Swiss population. Contact precaution is warranted for these persons if they enter medical care. In cases of infections, MRSA and ESBL-producing Enterobacteriaceae should be considered regarding antibiotic treatment choices. PMID:28085966

  17. 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…

  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. Burden of Invasive Staphylococcus aureus Infections in Hospitalized Infants

    PubMed Central

    Ericson, Jessica E.; Popoola, Victor O.; Smith, P. Brian; Benjamin, Daniel K.; Fowler, Vance G.; Benjamin, Daniel K.; Clark, Reese H.; Milstone, Aaron M.

    2015-01-01

    Importance Staphylococcus aureus is a frequent cause of infection in hospitalized infants. These infections are associated with increased mortality and morbidity, and longer hospital stays, but data on the burden of S. aureus disease in hospitalized infants are limited. Objective To compare demographics and mortality of infants with invasive methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA), determine the annual proportion of S. aureus infections that were MRSA, and compare the risk of death following an invasive MRSA infection to the risk following an invasive MSSA infection. Design Multicenter retrospective study of a large, nationally representative cohort. Setting 348 neonatal intensive care units managed by the Pediatrix Medical Group. Participants 3888 infants with an invasive S. aureus infection who were discharged between 1997 and 2012. Exposure Invasive S. aureus infection. Main Outcomes and Measures Incidence of invasive S. aureus infections. Infant characteristics and mortality following MRSA or MSSA infection. Results The 3888 infants had 3978 invasive S. aureus infections (2868 MSSA, 1110 MRSA). The incidence of invasive S. aureus infection was 44.8 infections/10,000 infants. The yearly proportion of invasive infections caused by MRSA increased from 1997 to 2006 and has remained relatively stable since then. Infants with invasive MRSA or MSSA infections had similar gestational ages and birth weights. Invasive MRSA infections occurred more often at a younger postnatal age. For infants with available mortality data, more infants with invasive MSSA infections died at hospital discharge (N=237) than those with invasive MRSA infections (N=110). The proportion of infants who died following invasive MSSA or MRSA infection were similar: 237/2474 (9.6%) and 110/926 (11.9%), P=.05, respectively. Adjusted risk of death at hospital discharge was similar after invasive MSSA and MRSA infections overall (risk ratio, 1.19; 95% CI, 0

  20. [The effectiveness of hand hygiene products on MRSA colonization of health care workers by using CHROMagar MRSA].

    PubMed

    Koçak Tufan, Zeliha; Irmak, Hasan; Bulut, Cemal; Cesur, Salih; Kınıklı, Sami; Demiröz, Ali Pekcan

    2012-04-01

    The aims of this study were; to investigate the hand hygiene compliance of the health care workers (HCWs) during their routine patient care, to determine the methicillin-resistant Staphylococcus aureus (MRSA) hand colonization of the HCWs, to investigate the effect of different hand hygiene products on MRSA colonization and to evaluate the effectiveness of chromogenic agar for detecting MRSA. HCWs were investigated during their routine patient care and hand cultures were taken before and after hand wash/hygiene. Two different techniques were used to obtain the hand cultures: fingertip method (CHROMagar MRSA containing HygiSlide); and direct swab method and then inoculation to CHROMagar MRSA media. MRSA strains grown on those cultures were confirmed with conventional methods. A total of 100 HCWs (of them 61 were female; mean age: 32.7 ± 5.2 years; age range: 25-51 years) involving physicians (n= 33), nurses (n= 38) and health care assistants (n= 29), were included in the study. MRSA was detected in 39% and 11% before hand hygiene and in 13% and 6% after hand hygiene, with HygiSlide CHROMagar media and with CHROMagar in plate media, respectively. No difference were found regarding clinics, occupations, or the type of patient handling in those HCWs who were positive (n= 13) for MRSA colonization following hand hygiene, and those who were negative (n= 26). However, the type of the hand hygiene product used exhibited a statistical difference. None of the seven HCWs who used alcohol based hand rub revealed growth in the second culture while 10 of 19 (53%) HCWs who used soap and three of 13 (23%) HCWs who used chlorhexidine were still colonized with MRSA. In terms of reduction in the MRSA counts, the most effective one was the alcohol based hand rub while the soap was the least, since seven of 19 (37%) HCWs who used soap showed no reduction at all in the MRSA counts. A high ratio of hand colonization with MRSA was detected in our hospital staff (39%). It was shown that

  1. Why is community-associated MRSA spreading across the world and how will it change clinical practice?

    PubMed

    Bassetti, Matteo; Nicco, Elena; Mikulska, Malgorzata

    2009-07-01

    Meticillin-resistant Staphylococcus aureus (MRSA) emerged in 1960 and over the following 40 years was a problem confined largely to the healthcare setting. In the late 1990s the first US reports of so-called community-associated MRSA (CA-MRSA) infections appeared. CA-MRSA infections were defined as MRSA infections occurring in patients who had no identifiable predisposing risk factors, such as healthy children and young adults. CA-MRSA is associated with a novel genetic profile and phenotype; it is remarkably fit and capable of spreading within communities, it is virulent and is often susceptible to multiple narrow-spectrum antimicrobials other than beta-lactams. CA-MRSA infections involve predominantly skin and soft tissue; however, necrotizing pneumonia and necrotizing fasciitis have been described. At present, several reports suggest that CA-MRSA may be replacing the hospital-acquired MRSA strains (HA-MRSA), with potentially catastrophic consequences. Given the rapid spread and the high virulence of CA-MRSA, global strategies are needed. Prompt, appropriate treatment, guided by the site and type of infection and risk factors for HA-MRSA or CA-MRSA, increases the chances of a successful outcome and is urgently needed.

  2. The Role of mgrA and sarA in Autolysis and Resistance to Cell Wall-Active Antibiotics in Methicillin-Resistant Staphylococcus aureus

    PubMed Central

    Trotonda, María Pilar; Xiong, Yan Q.; Memmi, Guido; Bayer, Arnold S.; Cheung, Ambrose L.

    2009-01-01

    Background We have previously shown the importance of mgrA and sarA in controlling autolysis of Staphylococcus aureus, with MgrA and SarA both being negative regulators of murein hydrolases. Methods In this study, we analyzed the effects of mgrA and sarA on antibiotic-mediated lysis in vitro, and on the responses to cell wall-active antibiotic therapy in an experimental endocarditis model using two representative MRSA strains: laboratory strain COL and community-acquired clinical isolate, MW2. Results We found that mgrA and sarA independently down-regulated sarV (a marker for autolysis), although the alteration in sarV expression did not correlate directly with the autolysis profiles of single mgrA and sarA mutants. Importantly, the mgrA/sarA double mutants of both strains were more autolytic in vitro as compared with the single mutants. In vivo, we demonstrated that, despite equivalent intrinsic virulence between the parents and their isogenic mgrA/sarA double mutants in the endocarditis model, oxacillin and vancomycin treatment of the mgrA/sarA double mutants of MRSA strains COL and MW2 yielded significant reductions in vegetation bacterial densities vs. their respective parents. Conclusions These results suggest that down-regulation of mgrA/sarA in combination with cell wall-active antibiotics may represent a novel approach to treat MRSA infections. PMID:19072553

  3. Amplitude-integrated electroencephalography and MRI findings in a case of severe neonatal methicillin-resistant Staphylococcus aureus meningitis

    PubMed Central

    Olischar, Monika; Hunt, Rod W; Daley, Andrew J; Clifford, Vanessa; Tingay, David G

    2010-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) can cause serious infection among hospitalised patients. The emergence of community acquired strains of MRSA (CA-MRSA) increases the potential exposure of newborns. The high incidence of reported meningitis in neonates in large CA-MRSA outbreaks suggests increased virulence in the neonatal population. The authors describe a case of severe meningitis due to MRSA in a previously healthy neonate and include findings from amplitude-integrated electroencephalography (aEEG) and MRI. PMID:22802366

  4. 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

  5. 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.

  6. 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.

  7. 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. ...

  8. 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...

  9. 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

  10. Whole-Genome Sequence for Methicillin-Resistant Staphylococcus aureus Strain ATCC BAA-1680.

    PubMed

    Daum, Luke T; Bumah, Violet V; Masson-Meyers, Daniela S; Khubbar, Manjeet; Rodriguez, John D; Fischer, Gerald W; Enwemeka, Chukuka S; Gradus, Steve; Bhattacharyya, Sanjib

    2015-03-12

    We report here the whole-genome sequence of the USA300 strain of methicillin-resistant Staphylococcus aureus (MRSA), designated ATCC BAA-1680, and commonly referred to as community-associated MRSA (CA-MRSA). This clinical MRSA isolate is commercially available from the American Type Culture Collection (ATCC) and is widely utilized as a control strain for research applications and clinical diagnosis. The isolate was propagated in ATCC medium 18, tryptic soy agar, and has been utilized as a model S. aureus strain in several studies, including MRSA genetic analysis after irradiation with 470-nm blue light.

  11. 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...

  12. A Staphylococcus aureus Proteome Overview: Shared and Specific Proteins and Protein Complexes from Representative Strains of All Three Clades.

    PubMed

    Liang, Chunguang; Schaack, Dominik; Srivastava, Mugdha; Gupta, Shishir K; Sarukhanyan, Edita; Giese, Anne; Pagels, Martin; Romanov, Natalie; Pané-Farré, Jan; Fuchs, Stephan; Dandekar, Thomas

    2016-02-19

    Staphylococcus aureus is an important model organism and pathogen. This S. aureus proteome overview details shared and specific proteins and selected virulence-relevant protein complexes from representative strains of all three major clades. To determine the strain distribution and major clades we used a refined strain comparison combining ribosomal RNA, MLST markers, and looking at highly-conserved regions shared between strains. This analysis shows three sub-clades (A-C) for S. aureus. As calculations are complex and strain annotation is quite time consuming we compare here key representatives of each clade with each other: model strains COL, USA300, Newman, and HG001 (clade A), model strain N315 and Mu50 (clade B) and ED133 and MRSA252 (clade C). We look at these individual proteomes and compare them to a background of 64 S. aureus strains. There are overall 13,284 S. aureus proteins not part of the core proteome which are involved in different strain-specific or more general complexes requiring detailed annotation and new experimental data to be accurately delineated. By comparison of the eight representative strains, we identify strain-specific proteins (e.g., 18 in COL, 105 in N315 and 44 in Newman) that characterize each strain and analyze pathogenicity islands if they contain such strain-specific proteins. We identify strain-specific protein repertoires involved in virulence, in cell wall metabolism, and phosphorylation. Finally we compare and analyze protein complexes conserved and well-characterized among S. aureus (a total of 103 complexes), as well as predict and analyze several individual protein complexes, including structure modeling in the three clades.

  13. A Staphylococcus aureus Proteome Overview: Shared and Specific Proteins and Protein Complexes from Representative Strains of All Three Clades

    PubMed Central

    Liang, Chunguang; Schaack, Dominik; Srivastava, Mugdha; Gupta, Shishir K.; Sarukhanyan, Edita; Giese, Anne; Pagels, Martin; Romanov, Natalie; Pané-Farré, Jan; Fuchs, Stephan; Dandekar, Thomas

    2016-01-01

    Staphylococcus aureus is an important model organism and pathogen. This S. aureus proteome overview details shared and specific proteins and selected virulence-relevant protein complexes from representative strains of all three major clades. To determine the strain distribution and major clades we used a refined strain comparison combining ribosomal RNA, MLST markers, and looking at highly-conserved regions shared between strains. This analysis shows three sub-clades (A–C) for S. aureus. As calculations are complex and strain annotation is quite time consuming we compare here key representatives of each clade with each other: model strains COL, USA300, Newman, and HG001 (clade A), model strain N315 and Mu50 (clade B) and ED133 and MRSA252 (clade C). We look at these individual proteomes and compare them to a background of 64 S. aureus strains. There are overall 13,284 S. aureus proteins not part of the core proteome which are involved in different strain-specific or more general complexes requiring detailed annotation and new experimental data to be accurately delineated. By comparison of the eight representative strains, we identify strain-specific proteins (e.g., 18 in COL, 105 in N315 and 44 in Newman) that characterize each strain and analyze pathogenicity islands if they contain such strain-specific proteins. We identify strain-specific protein repertoires involved in virulence, in cell wall metabolism, and phosphorylation. Finally we compare and analyze protein complexes conserved and well-characterized among S. aureus (a total of 103 complexes), as well as predict and analyze several individual protein complexes, including structure modeling in the three clades. PMID:28248218

  14. Complete Genome Sequence of Staphylococcus aureus Strain Wood 46

    PubMed Central

    Balachandran, Manasi; Riley, Matthew C.; Bemis, David A.

    2017-01-01

    ABSTRACT Here, we report the first complete genome sequence of the Staphylococcus aureus strain Wood 46. Wood 46 has played an important role in understanding the virulence and pathogenesis of S. aureus infections. This report will assist efforts in vaccine development against methicillin-resistant S. aureus (MRSA) infections. PMID:28360163

  15. Complete Genome Sequence of Staphylococcus aureus Strain Wood 46.

    PubMed

    Balachandran, Manasi; Riley, Matthew C; Bemis, David A; Kania, Stephen A

    2017-03-30

    Here, we report the first complete genome sequence of the Staphylococcus aureus strain Wood 46. Wood 46 has played an important role in understanding the virulence and pathogenesis of S. aureus infections. This report will assist efforts in vaccine development against methicillin-resistant S. aureus (MRSA) infections.

  16. Molecular nature of methicillin-resistant Staphylococcus aureus derived from explosive nosocomial outbreaks of the 1980s in Japan.

    PubMed

    Taneike, Ikue; Otsuka, Taketo; Dohmae, Soshi; Saito, Kohei; Ozaki, Kyoko; Takano, Misao; Higuchi, Wataru; Takano, Tomomi; Yamamoto, Tatsuo

    2006-04-17

    Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) with Panton-Valentine leukocidin (PVL) genes is increasing worldwide. Nosocomial outbreak-derived (hospital-acquired) MRSA (HA-MRSA) in Japan in the 1980s was also largely PVL(+). PVL(+) HA-MRSA and CA-MRSA shared the same multi-locus sequence type (ST30) and methicillin resistance cassette (SCCmecIV), but were divergent in oxacillin resistance, spa typing, PFGE analysis or clfA gene analysis. PVL(+) HA-MRSA, which probably originated in PVL(+)S. aureus ST30, was highly adhesive (carrying cna and bbp genes), highly-toxic (carrying luk(PV) and sea genes) and highly drug-resistant. PVL(+) HA-MRSA was once replaced by other PVL(-) HA-MRSA (e.g., ST5), and is re-emerging as CA-MRSA.

  17. 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

  18. Transferable Vancomycin Resistance in a Community-Associated MRSA Lineage

    PubMed Central

    Rossi, Flávia; Diaz, Lorena; Wollam, Aye; Panesso, Diana; Zhou, Yanjiao; Rincon, Sandra; Narechania, Apurva; Xing, Galen; Di Gioia, Thais S.R.; Doi, André; Tran, Truc T.; Reyes, Jinnethe; Munita, Jose M.; Carvajal, Lina P.; Hernandez-Roldan, Alejandra; Brandão, Denise; van der Heijden, Inneke Marie; Murray, Barbara E.; Planet, Paul J.; Weinstock, George M.; Arias, Cesar A.

    2014-01-01

    SUMMARY We report the case of a patient from Brazil with a bloodstream infection caused by a strain of methicillin-resistant Staphylococcus aureus (MRSA) that was susceptible to vancomycin (designated BR-VSSA) but that acquired the vanA gene cluster during antibiotic therapy and became resistant to vancomycin (designated BR-VRSA). Both strains belong to the sequence type (ST) 8 community-associated genetic lineage that carries the staphylococcal chromosomal cassette mec (SCCmec) type IVa and the S. aureus protein A gene (spa) type t292 and are phylogenetically related to MRSA lineage USA300. A conjugative plasmid of 55,706 bp (pBRZ01) carrying the vanA cluster was identified and readily transferred to other staphylococci. The pBRZ01 plasmid harbors DNA sequences that are typical of the plasmid-associated replication genes rep24 or rep21 described in community-associated MRSA strains from Australia (pWBG745). The presence and dissemination of community-associated MRSA containing vanA could become a serious public health concern. PMID:24738669

  19. Anti-MRSA cephems. Part 3: additional C-7 acid derivatives.

    PubMed

    Springer, Dane M; Luh, Bing Yu; Goodrich, Jason T; Bronson, Joanne J

    2003-01-17

    Twenty-seven novel cephalosporin derivatives with activity against methicillin-resistant Staphylococcus aureus (MRSA) are described. The compounds contain novel acid moieties at C-7 that were synthesized using nucleophilic aromatic substitution reactions and Stille couplings. The most interesting compound (6) displayed an MIC(90) against MRSA of 3.7 microg/mL, and an average PD(50) of 3.9 mg/kg.

  20. MRSA prevention and control in county correctional facilities in Southwestern Ohio.

    PubMed

    Webb, Jeffrey A; Czachor, John S

    2009-10-01

    The number of methicillin-resistant Staphylococcus aureus (MRSA) infections in correctional facilities around the country has been increasing. Considering the potential health impact of MRSA, it is important that correctional facilities have prevention and control protocols in place. The study results summarize the prevention and control preparedness activities of county jails in the Greater Dayton area of Ohio. Protocols and control measures were in place for environmental control (95.4%), MRSA screening (88.4%), standard precautions (84.3%), treatment (83.6%), personal hygiene (80.6%), and education (80.4%). Statistical analysis found no significant difference between rural and urban county jails in their handling of MRSA issues. The findings suggest significant compliance with MRSA prevention and control protocols among county jails in the Greater Dayton area.

  1. 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.

  2. First Outbreak with MRSA in a Danish Neonatal Intensive Care Unit: Risk Factors and Control Procedures

    PubMed Central

    Ramsing, Benedicte Grenness Utke; Arpi, Magnus; Andersen, Erik Arthur; Knabe, Niels; Mogensen, Dorthe; Buhl, Dorte; Westh, Henrik; Østergaard, Christian

    2013-01-01

    Introduction The purpose of the study was to describe demographic and clinical characteristics and outbreak handling of a large methicillin-resistant Staphylococcus aureus (MRSA) outbreak in a neonatal intensive care unit (NICU) in Denmark June 25th–August 8th 2008, and to identify risk factors for MRSA transmission. Methods Data were collected retrospectively from medical records and the Danish Neobase database. All MRSA isolates obtained from neonates, relatives and NICU health care workers (HCW) as well as environmental cultures were typed. Results During the 46 day outbreak period, 102 neonates were admitted to the two neonatal wards. Ninety-nine neonates were subsequently sampled, and 32 neonates (32%) from 25 families were colonized with MRSA (spa-type t127, SCCmec V, PVL negative). Thirteen family members from 11 of those families (44%) and two of 161 HCWs (1%) were colonized with the same MRSA. No one was infected. Five environmental cultures were MRSA positive. In a multiple logistic regression analysis, nasal Continuous Positive Airway Pressure (nCPAP) treatment (p = 0.006) and Caesarean section (p = 0.016) were independent risk factors for MRSA acquisition, whereas days of exposure to MRSA was a risk factors in the unadjusted analysis (p = 0.04). Conclusions MRSA transmission occurs with high frequency in the NICU during hospitalization with unidentified MRSA neonates. Caesarean section and nCPAP treatment were identified as risk factors for MRSA colonization. The MRSA outbreak was controlled through infection control procedures. PMID:23825581

  3. [The formation and spread of MRSA strains in patients with pyoinflammatory diseases].

    PubMed

    Gasretova, T D; Sin'kova, O N; Charseeva, G G; Mironov, A Iu

    2013-04-01

    The article considers the results of study of formation and spread of MRSA in patients with suppurative focuses of stafillococus ethiology after application of antibacterial therapy. The antibacterial therapy applied to these patients used one of the following pharmaceuticals--cefazolin, lincomycin, gentamicin, oxampicin, ciprofloxacin, ofloxacin. All the strains of S. aureus ssp. aureus isolated from patients were tested on MRSA. Their phagovars were detected using international kit of phages for grouping of S. aureus ssp. aureus. The comparison of data received after analysis of resistance to oxacillin of strains and their phages isolated at the onset of disease and after applied treatment was carried out. The study established that against the background of applied antibacterial therapy in 10.7% of patients, MRSA formed and in 15.4% of patients, the change of initial strains of S. aureus ssp. aureus by MRSA strains of other phages groups was established. The presented results testified the need of obligatory testing of strains isolated from patients with staphylococcus infection on antibiotics resistance. The application of antibacterial therapy and its correction taking in account the laboratory data on antibiotics resistance and strict following the sanitary hygienic standards.

  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. 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.

  6. Demographic screening for MRSA may compromise the effectiveness of ring fencing on a joint replacement unit.

    PubMed

    Schmidt, H-M A; Izon, C; Maley, M W

    2012-11-01

    Ring fencing of joint replacement (JR) units has been reported to reduce infections and is recommended by health authorities in Australia and the UK. It has not been determined whether a demographic risk assessment is adequate to prevent the admission of patients colonized with meticillin-resistant Staphylococcus aureus (MRSA) to ring-fenced units. As such, 250 admissions to the JR unit of a suburban Sydney hospital were screened, and MRSA colonization was identified in 2.8% of patients complying with the demographic risk assessment. Demographic risk assessment is not an adequate substitute for physical MRSA screening, and undermines the effectiveness of ring-fencing procedures.

  7. 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.

  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.

  9. Comparison of bactericidal activities of various disinfectants against methicillin-sensitive Staphylococcus aureus and methicillin-resistant Staphylococcus aureus.

    PubMed

    Yasuda, T; Yoshimura, S; Katsuno, Y; Takada, H; Ito, M; Takahashi, M; Yahazaki, F; Iriyama, J; Ishigo, S; Asano, Y

    1993-01-01

    Various disinfectants were compared in terms of the duration of bactericidal activity against methicillin-sensitive Staphylococcus aureus (MSSA), and methicillin-resistant Staphylococcus aureus (MRSA), among S. aureus isolated in our hospital. Strains of S. aureus which showed minimum inhibitory concentrations of cloxacillin of less than 1.56 micrograms/ml and of 3.13 micrograms/ml or higher were designated MSSA and MRSA respectively. There was no difference in sensitivity to disinfectants between MSSA and MRSA. There was a great variation in the duration of bactericidal activity of chlorhexidine gluconate against these species with the majority requiring contact times of between 2 minutes and over 20 minutes. All strains except for one strain of MRSA were killed within 20 seconds after disinfection with benzalkonium chloride. All strains were killed within 20 seconds after disinfection with alkyldiaminoethylglycine hydrochloride or povidone-iodine.

  10. 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.

  11. Whole Genome Sequencing of a Methicillin-Resistant Staphylococcus aureus Pseudo-Outbreak in a Professional Football Team

    PubMed Central

    Anderson, Deverick J.; Harris, Simon R.; Godofsky, Eliot; Toriscelli, Todd; Rude, Thomas H.; Elder, Kevin; Sexton, Daniel J.; Pellman, Elliot J.; Mayer, Thom; Fowler, Vance G.; Peacock, Sharon J.

    2014-01-01

    Two American football players on the same team were diagnosed with methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infections on the same day. Our investigation, including whole genome sequencing, confirmed that players did not transmit MRSA to one another nor did they acquire the MRSA from a single source within the training facility. PMID:25734164

  12. Clonality and Antimicrobial Susceptibility of Staphylococcus aureus and Methicillin-Resistant S. aureus Isolates from Food Animals and Other Animals

    PubMed Central

    Chow, Kin-Hung; Lai, Eileen L.; Law, Pierra Y. T.; Chan, Pui-Ying; Ho, Alex Y. M.; Ng, Tak-Keung; Yam, Wing-Cheong

    2012-01-01

    Out of 3,081 animals studied, 24.9% of pigs, 4.7% of chickens, 6.3% of dogs, 10.5% of cats, and 7.1% of rodents were Staphylococcus aureus positive. Prevalence of methicillin-resistant S. aureus (MRSA) was high in pigs (animals, 21.3%; batches, 46.5%), with all MRSA isolates and most methicillin-sensitive S. aureus isolates belonging to clonal complex 9 (CC9) and being multidrug resistant. The predominant S. aureus CCs among dog and cat isolates were similar. Among rodent isolates, CC398 predominated, with spa t034 the most frequent spa type detected. PMID:22895044

  13. Clonality and antimicrobial susceptibility of Staphylococcus aureus and methicillin-resistant S. aureus isolates from food animals and other animals.

    PubMed

    Ho, Pak-Leung; Chow, Kin-Hung; Lai, Eileen L; Law, Pierra Y T; Chan, Pui-Ying; Ho, Alex Y M; Ng, Tak-Keung; Yam, Wing-Cheong

    2012-11-01

    Out of 3,081 animals studied, 24.9% of pigs, 4.7% of chickens, 6.3% of dogs, 10.5% of cats, and 7.1% of rodents were Staphylococcus aureus positive. Prevalence of methicillin-resistant S. aureus (MRSA) was high in pigs (animals, 21.3%; batches, 46.5%), with all MRSA isolates and most methicillin-sensitive S. aureus isolates belonging to clonal complex 9 (CC9) and being multidrug resistant. The predominant S. aureus CCs among dog and cat isolates were similar. Among rodent isolates, CC398 predominated, with spa t034 the most frequent spa type detected.

  14. Mobile genetic element SCCmec-encoded psm-mec RNA suppresses translation of agrA and attenuates MRSA virulence.

    PubMed

    Kaito, Chikara; Saito, Yuki; Ikuo, Mariko; Omae, Yosuke; Mao, Han; Nagano, Gentaro; Fujiyuki, Tomoko; Numata, Shunsuke; Han, Xiao; Obata, Kazuaki; Hasegawa, Setsuo; Yamaguchi, Hiroki; Inokuchi, Koiti; Ito, Teruyo; Hiramatsu, Keiichi; Sekimizu, Kazuhisa

    2013-01-01

    Community acquired-methicillin resistant Staphylococcus aureus (CA-MRSA) is a socially problematic pathogen that infects healthy individuals, causing severe disease. CA-MRSA is more virulent than hospital associated-MRSA (HA-MRSA). The underlying mechanism for the high virulence of CA-MRSA is not known. The transcription product of the psm-mec gene, located in the mobile genetic element SCCmec of HA-MRSA, but not CA-MRSA, suppresses the expression of phenol-soluble modulin α (PSMα), a cytolytic toxin of S. aureus. Here we report that psm-mec RNA inhibits translation of the agrA gene encoding a positive transcription factor for the PSMα gene via specific binding to agrA mRNA. Furthermore, 25% of 325 clinical MRSA isolates had a mutation in the psm-mec promoter that attenuated transcription, and 9% of the strains had no psm-mec. In most of these psm-mec-mutated or psm-mec-deleted HA-MRSAs, PSMα expression was increased compared with strains carrying intact psm-mec, and some mutated strains produced high amounts of PSMα comparable with that of CA-MRSA. Deletion of psm-mec from HA-MRSA strains carrying intact psm-mec increased the expression of AgrA protein and PSMα, and virulence in mice. Thus, psm-mec RNA suppresses MRSA virulence via inhibition of agrA translation and the absence of psm-mec function in CA-MRSA causes its high virulence property.

  15. An effective active surveillance method for controlling nosocomial MRSA transmission in a Japanese hospital.

    PubMed

    Ohkushi, Daisuke; Uehara, Yuki; Iwamoto, Akira; Misawa, Shigeki; Kondo, Shigemi; Shimizu, Kenichiro; Hori, Satoshi; Hiramatsu, Keiichi

    2013-10-01

    Hospital-wide active surveillance for methicillin-resistant Staphylococcus aureus (MRSA) targeted to adult patients with a history of MRSA carriage within the past 5 years was performed in Juntendo University Hospital (JUH) over a 2-year period. In the first year, MRSA screening culture was ordered by physicians in charge. In the second year, infection-control practitioners (ICPs) took samples for active surveillance culture. The average monthly transmission rate of MRSA in JUH was 0.35 per 1,000 bed-days in the first year and decreased significantly to 0.26 per 1,000 bed-days in the second year (P < 0.05). In the second year, more active commitment of ICPs to MRSA screening was effective in improving the performance rate of screening, shortening turn-around time of screening results, and decreasing transmission rate. Increasing compliance with active MRSA surveillance by involvement of ICPs, targeting patients with a previous history of MRSA carriage in the previous 5 years, was effective to control nosocomial MRSA transmission.

  16. Staphylococcus aureus infections in Australasian neonatal nurseries

    PubMed Central

    Isaacs, D; Fraser, S; Hogg, G; Li, H

    2004-01-01

    Objective: To study the incidence and outcome of systemic infections with methicillin sensitive (MSSA) and methicillin resistant Staphylococcus aureus (MRSA) infections in Australasian neonatal nurseries. Methods: Prospective longitudinal study of systemic infections (clinical sepsis plus positive cultures of blood and/or cerebrospinal fluid) in 17 Australasian neonatal nurseries. Results: The incidence of early onset sepsis with S aureus, mainly MSSA, was 19 cases per 244 718 live births or 0.08 per 1000. From 1992 to 1994, MRSA infections caused only 8% of staphylococcal infections. From 1995 to 1998, there was an outbreak of MRSA infection, in two Melbourne hospitals. The outbreak resolved, after the use of topical mupirocin and improved handwashing. Babies with MRSA sepsis were significantly smaller than babies with MSSA sepsis (mean birth weight 1093 v 1617 g) and more preterm (mean gestation 27.5 v 30.3 weeks). The mortality of MRSA sepsis was 24.6% compared with 9.9% for MSSA infections. The mortality of early onset MSSA sepsis, however, was 39% (seven of 18) compared with 7.3% of late onset MSSA infection presenting more than two days after birth. Conclusions: S aureus is a rare but important cause of early onset sepsis. Late onset MRSA infections carried a higher mortality than late onset MSSA infections, but babies with early onset MSSA sepsis had a particularly high mortality. PMID:15210669

  17. Staphylococcus aureus Keratitis: A Review of Hospital Cases

    PubMed Central

    Ong, Sherine Jue; Huang, Yhu-Chering; Tan, Hsin-Yuan; Ma, David H. K.; Lin, Hsin-Chiung; Yeh, Lung-Kun; Chen, Phil Y. F.; Chen, Hung-Chi; Chuang, Chih-Chun; Chang, Chee-Jen; Hsiao, Ching-Hsi

    2013-01-01

    Background Methicillin-resistant Staphylococcus aureus (MRSA) infection is an important public health issue. The study aimed to characterize the patient demographics, clinical features, antibiotic susceptibility, and clinical outcomes of keratitis caused by S. aureus, and to make a comparison between MRSA and methicillin-sensitive S. aureus (MSSA) isolates. Methodology/Principal findings Patients (n = 59) with culture-proven S. aureus keratitis treated in Chang Gung Memorial Hospital between January 1, 2006, and December 31, 2010, were included in our study. Patients' demographic and clinical data were retrospectively reviewed. Twenty-six MRSA (44%) and 33 MSSA (56%) isolates were collected. The MRSA keratitis was significantly more common among the patients with healthcare exposure (P = 0.038), but 46.2% (12/26) of patients with MRSA keratitis were considered to have community-associated infections. All isolates were susceptible to vancomycin. MRSA isolates were significantly more resistant to clindamycin, erythromycin, and sulfamethoxazole/trimethoprim. Ocular surface disease was a significant risk factor for MRSA keratitis (P = 0.011). Visual outcome did not differ significantly between the MRSA and MSSA groups. However, age (B = 0.01, P = 0.035, 95% confidence interval [CI]: 0.001–0.019) and visual acuity at presentation (B = 0.749, P<0.001, 95% CI: 0.573–0.926) were significantly correlated with visual outcome. Conclusions/Significance Ocular surface disease is an important predisposing factor for S. aureus keratitis, especially for MRSA infections. Advanced age and poor visual acuity at presentation are important prognostic indicators for poor visual outcome in S. aureus keratitis. Oxacillin resistance may not be a significant prognostic indicator. PMID:24244625

  18. 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.

  19. 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

  20. 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.

  1. Serious infection from Staphylococcus aureus in 2 HIV-infected patients receiving fusion inhibitor therapy.

    PubMed

    Gaughan, Elizabeth M; Ritter, Michelle L; Kumar, Princy N; Timpone, Joseph G

    2008-05-01

    Fusion inhibitors are novel antiretroviral agents, administered as subcutaneous injections, approved for use in treatment-experienced HIV-infected patients. HIV-infected patients are at increased risk for Staphylococcus aureus colonization, specifically with methicillin-resistant S aureus (MRSA), and subsequent systemic infection. We present the cases of 2 patients without a history of MRSA infection in whom a series of severe S aureus infections developed after fusion inhibitor therapy.

  2. 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.

  3. 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...

  4. 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.

  5. Impact of Rapid Screening for Discontinuation of MRSA Contact Precautions

    PubMed Central

    Shenoy, Erica S.; Lee, Hang; Cotter, Jessica A.; Ware, Winston; Kelbaugh, Douglas; Weil, Eric; Walensky, Rochelle P.; Hooper, David C.

    2015-01-01

    Background A history of methicillin-resistant Staphylococcus aureus (MRSA) is a determinant of inpatient bed assignment. Methods We assessed outcomes associated with rapid testing and discontinuation of MRSA Contact Precautions (CP) in a prospective cohort study of PCR-based screening in the Emergency Department (ED) of the Massachusetts General Hospital. Eligible patients had a history of MRSA and were assessed and enrolled if documented off antibiotics with activity against MRSA and screened for nasal colonization (subject-visit). PCR-negative subjects had CP discontinued; the primary outcome was CP-discontinuation. We identified semi-private rooms in which a bed was vacant due to the CP status of the study subject, calculated the hours of vacancy, and compared idle bed hours by PCR results. Program costs were compared to predicted revenue. Results There were 2,864 eligible patients; 648 (22.6%) subject-visits were enrolled. Of these, 65.1% (422/648) were PCR-negative and had CP discontinued. PCR-negative subjects had fewer idle bed hours compared to PCR-positive (28.6 ± 25.2 vs. 75.3 ± 70.5, p<0.001). The expected revenues from occupied idle beds and averted CP costs ranged from $214,160 to $268,340, and exceeded program costs. Discussion PCR-based screening for persistence of colonization effectively identified patients who cleared MRSA colonization. Conclusion A program of targeted screening for clearance of MRSA colonization resulted in expected revenues and decreased CP costs that outweighed programmatic costs. PMID:26440593

  6. The Posttranslocational Chaperone Lipoprotein PrsA Is Involved in both Glycopeptide and Oxacillin Resistance in Staphylococcus aureus

    PubMed Central

    Jousselin, Ambre; Renzoni, Adriana; Andrey, Diego O.; Monod, Antoinette; Lew, Daniel P.

    2012-01-01

    Understanding in detail the factors which permit Staphylococcus aureus to counteract cell wall-active antibiotics is a prerequisite to elaborating effective strategies to prolong the usefulness of these drugs and define new targets for pharmacological intervention. Methicillin-resistant S. aureus (MRSA) strains are major pathogens of hospital-acquired and community-acquired infections and are most often treated with glycopeptides (vancomycin and teicoplanin) because of their resistance to most penicillins and a limited arsenal of clinically proven alternatives. In this study, we examined PrsA, a lipid-anchored protein of the parvulin PPIase family (peptidyl-prolyl cis/trans isomerase) found ubiquitously in all Gram-positive species, in which it assists posttranslocational folding at the outer surface of the cytoplasmic membrane. We show by both genetic and biochemical assays that prsA is directly regulated by the VraRS two-component sentinel system of cell wall stress. Disruption of prsA is tolerated by S. aureus, and its loss results in no detectable overt macroscopic changes in cell wall architecture or growth rate under nonstressed growth conditions. Disruption of prsA leads, however, to notable alterations in the sensitivity to glycopeptides and dramatically decreases the resistance of COL (MRSA) to oxacillin. Quantitative transcriptional analysis reveals that prsA and vraR are coordinately upregulated in a panel of stable laboratory and clinical glycopeptide-intermediate S. aureus (GISA) strains compared to their susceptible parents. Collectively, our results point to a role for prsA as a facultative facilitator of protein secretion or extracellular folding and provide a framework for understanding why prsA is a key element of the VraRS-mediated cell wall stress response. PMID:22526301

  7. Prospective Two-Center Comparison of Three Chromogenic Agars for Methicillin-Resistant Staphylococcus aureus Screening in Hospitalized Patients

    PubMed Central

    Verhulst, Carlo; Nonhoff, Claire; Nagant, Carole; Denis, Olivier; Kluytmans, Jan

    2015-01-01

    Three chromogenic media, chromID MRSA SMART (SMART), chromID MRSA first generation (chromID), and Brilliance MRSA (OX2), were evaluated for methicillin-resistant Staphylococcus aureus (MRSA) screening using 1,220 samples. The sensitivity at 24 h was significantly better with the SMART agar (66.4%) than that with chromID agar (50.5%). Enrichment and incubation until 48 h are still needed for an optimal yield. PMID:26109446

  8. Prospective Analysis Methicillin-resistant Staphylococcus aureus and its Risk Factors

    PubMed Central

    Abdallah, Soad A; Al-Asfoor, Khulood K; Salama, Mona F; Al-Awadi, Bashayer M

    2013-01-01

    Background: Since the early nineties, a new methicillin-resistant Staphylococcus aureus (MRSA) has existed in a form correlating with community health personnel. Community-acquired MRSA (CA-MRSA) could be differentiated from healthcare-associated MRSA (HA-MRSA) microbiologically, epidemiologically, and molecularly. Aims: To determine the prevalence, risk factors of MRSA infections in community and hospital. Settings: The incidence and risk factors for CA-MRSA and HA-MRSA among patients of medical, surgical, and pediatrics wards and ICU at a Kuwaiti teaching hospital between 1 March 2011 and 30 November 2011 were studied. Materials and Methods: Cultures for MRSA were taken from nasal (nostril), groin, axilla, wound, sputum, or throat, and the inguinal area in all enrolled patients upon admission. All preserved isolates were examined for their susceptibility to different types of antibiotics. Results and Conclusion: A total of 71 MRSA patients admitted to different hospital wards were examined. Among these patients, 52 (73.2%) were carriers of MRSA before they were admitted to the hospital. Nineteen patients (26.8%) were found to have acquired MRSA during their stay in the hospital. Twenty-nine patients (40.8%) were given mupirocin local skin antibiotic. Binomial and the t-test (paired) were used to compare the prevalence of CA-MRSA and HA-MRSA; significant correlation (P < 0.05) between the type of MRSA and different wards, sites, and lengths of hospital stay was found. The level of serum albumin that is routinely measured at hospital admission is a predictor to MRSA infection. This study suggests that S. aureus and MRSA should become a national priority for disease control to avoid outbreaks. PMID:23599613

  9. 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.

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

    PubMed Central

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

    2014-01-01

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

  11. 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.

  12. Rapid detection of methicillin-resistant Staphylococcus aureus strains not identified by slide agglutination tests.

    PubMed Central

    Kuusela, P; Hildén, P; Savolainen, K; Vuento, M; Lyytikäinen, O; Vuopio-Varkila, J

    1994-01-01

    Seventy-nine methicillin-resistant Staphylococcus aureus (MRSA) strains, isolated during 1980 to 1990, were classified as MRSA Aggl- (14 strains) and MRSA Aggl+ (65 strains) strains on the basis of test results in slide agglutination assays designed to detect fibrinogen-binding protein (clumping factor) and protein A on the staphylococcal surface. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed that lysostaphin digests of MRSA Aggl- strains contained a high-molecular-weight protein which was not detected in digests of MRSA Aggl+ strains. Immunization of rabbits with an MRSA Aggl- strain produced an antiserum which agglutinated all MRSA Aggl- strains and also 64 of 65 MRSA Aggl+ strains. Only 1 of 68 coagulase-negative staphylococci showed agglutination in this assay. The anti-MRSA Aggl- antiserum reacted mainly with a 230-kDa staphylococcal surface protein but also with a 175-kDa protein, probably formed by proteolysis of the former and a few slightly smaller proteins. These could not be immunologically detected in lysostaphin digests of MRSA Aggl+ strains. Purified antibodies reacting with the 230-kDa protein agglutinated all MRSA Aggl- strains, indicating that the protein is located on the surfaces of staphylococci. The results suggest a tentative role for the 230-kDa protein or its fragments as a novel target to develop more efficient rapid identification methods for S. aureus, including MRSA. Images PMID:8126170

  13. [Is it necessary to know which workers are carriers of MRSA in contact with cancer patients?].

    PubMed

    García-Lozano, Tomás; Egido, Adoración; Contel, Elena; Picón, María Isabel; Martínez, María Ángeles; Aznar, Eduardo

    2012-12-01

    Our objective was to determine the prevalence of methicillin-resistant Staphylococcus aureus in workers who had direct contact with oncologic patients infected with MRSA and admitted to the intensive care unit of the Valencian Institute of Oncology. A study of prevalence of MRSA colonization of 62 workers was performed. Samples were taken from nose and pharynx in each of the workers. After 24 hours of incubation in Amies transport medium Viscose (Eurotubo®), 124 samples were seeded (N = 124) in chocolate agar agar, MRSA II and BHI broth (Brain Heart Infusion). Those colonies that were identified by Gram stain gram-positive cocci in clusters available, catalase positive and coagulase positive were processed for study of sensitivity by Kirby-Bauer method and screening test for methicillin (10μg of Oxoid®) on Mueller-Hinton (Becton-Dickinson®, BD), supplemented with NaCl (2%). Those confirmed MRSA isolates, he returned to perform sensitivity study by microdilution (MicroScan®, Siemens) to determine the MIC (mg/L). The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) was 1.61% (1) and 12.90% (8) for methicillin-sensitive Staphylococcus aureus (MSSA), from nostrils. The measures implemented were: nasal application of mupirocin to the worker colonized control isolation measures in infected patients and indoctrination of the personnel involved.

  14. 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

  15. VanA-Type MRSA (VRSA) Emerged in Surface Waters.

    PubMed

    Icgen, Bulent

    2016-09-01

    Due to the widespread occurrence of mecA-encoded methicillin resistance in Staphylococcus aureus (MRSA), treatment of staphylococcal infections is shifted to glycopeptide antibiotics like vancomycin and teicoplanin. The selective pressure of glycopeptides has eventually led to the emergence of staphylococci with increased resistance. Of great concern is vanA-encoded high level vancomycin and teicoplanin resistance in MRSA (VRSA). Therefore, this study aimed at investigating the occurrence of VRSA in surface waters. Out of 290, two staphylococcal isolates identified as MRSA Al11, Ba01, and one as MRS Co11 through 16S rRNA sequencing, also displayed high level resistance towards vancomycin and teicoplanin. These staphylococcal isolates were found to harbor vanA gene with sequence similarities of 99 %-100 % to the vanA gene extracted from vancomycin- and teicoplanin-resistant enterococcal (VRE) surface water isolates of Enterococcus faecalis Cr07, E07, Pb06 and E. faecium E330. High level glycopeptide resistance rendering protein encoded by the vanA gene, D-alanine-D-lactate ligase found in VRE, was also shown to be present in all vanA-type staphylococcal isolates through western blot. Current study elucidated that surface waters provide high potential for enterococcal vanA gene being transferred to MRSA, so called VRSA, and require special scientific consideration.

  16. Molecular Characterization of a Catalase-Negative Methicillin-Susceptible Staphylococcus aureus subsp. aureus Strain Collected from a Patient with Cutaneous Abscess

    PubMed Central

    Johnson, Ryan C.; Crawford, Katrina; Lanier, Jeffrey B.; Merrell, D. Scott

    2014-01-01

    We describe a cutaneous abscess caused by catalase-negative methicillin-susceptible Staphylococcus aureus subsp. aureus in a patient who was concomitantly colonized with virulent USA300 methicillin-resistant S. aureus (MRSA). Sequencing of the katA gene demonstrated a thymine insertion leading to a frameshift mutation and premature truncation of catalase to 21 amino acids. PMID:24131694

  17. Local circulating clones of Staphylococcus aureus in Ecuador.

    PubMed

    Zurita, Jeannete; Barba, Pedro; Ortega-Paredes, David; Mora, Marcelo; Rivadeneira, Sebastián

    The spread of pandemic Staphylococcus aureus clones, mainly methicillin-resistant S. aureus (MRSA), must be kept under surveillance to assemble an accurate, local epidemiological analysis. In Ecuador, the prevalence of the USA300 Latin American variant clone (USA300-LV) is well known; however, there is little information about other circulating clones. The aim of this work was to identify the sequence types (ST) using a Multiple-Locus Variable number tandem repeat Analysis 14-locus genotyping approach. We analyzed 132 S. aureus strains that were recovered from 2005 to 2013 and isolated in several clinical settings in Quito, Ecuador. MRSA isolates composed 46.97% (62/132) of the study population. Within MRSA, 37 isolates were related to the USA300-LV clone (ST8-MRSA-IV, Panton-Valentine Leukocidin [PVL] +) and 10 were related to the Brazilian clone (ST239-MRSA-III, PVL-). Additionally, two isolates (ST5-MRSA-II, PVL-) were related to the New York/Japan clone. One isolate was related to the Pediatric clone (ST5-MRSA-IV, PVL-), one isolate (ST45-MRSA-II, PVL-) was related to the USA600 clone, and one (ST22-MRSA-IV, PVL-) was related to the epidemic UK-EMRSA-15 clone. Moreover, the most prevalent MSSA sequence types were ST8 (11 isolates), ST45 (8 isolates), ST30 (8 isolates), ST5 (7 isolates) and ST22 (6 isolates). Additionally, we found one isolate that was related to the livestock associated S. aureus clone ST398. We conclude that in addition to the high prevalence of clone LV-ST8-MRSA-IV, other epidemic clones are circulating in Quito, such as the Brazilian, Pediatric and New York/Japan clones. The USA600 and UK-EMRSA-15 clones, which were not previously described in Ecuador, were also found. Moreover, we found evidence of the presence of the livestock associated clone ST398 in a hospital environment.

  18. Prevalence of Staphylococcus aureus and of methicillin-resistant S. aureus clonal complexes in bulk tank milk from dairy cattle herds in Lombardy Region (Northern Italy).

    PubMed

    Cortimiglia, C; Luini, M; Bianchini, V; Marzagalli, L; Vezzoli, F; Avisani, D; Bertoletti, M; Ianzano, A; Franco, A; Battisti, A

    2016-10-01

    Staphylococcus aureus is the most important causative agent of subclinical mastitis in cattle resulting in reduced milk production and quality. Methicillin-resistant S. aureus (MRSA) strains has a clear zoonotic relevance, especially in the case of occupational exposure. The aim of the study was to evaluate the prevalence of S. aureus and MRSA in bulk tank milk (BTM) from dairy cattle herds in the Lombardy Region (Northern Italy) and to identify the main MRSA circulating genotypes. MRSA strains were characterized by susceptibility testing, multi-locus sequence typing (MLST), spa typing and SCCmec typing. A total 844 BTM samples were analysed and S. aureus and MRSA were detected in 47·2% and 3·8% of dairy herds, respectively. MLST showed that the majority (28/32) of isolates belonged to the typical livestock-associated lineages: ST398, ST97 and ST1. Interestingly, in this study we report for the first time the new ST3211, a single locus variant of ST(CC)22, with the newly described 462 aroE allele. Our study indicates high diffusion of S. aureus mastitis and low, but not negligible, prevalence of MRSA in the considered area, suggesting the need for planning specific control programmes for bovine mastitis caused by S. aureus, especially when MRSA is implicated.

  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. Staphylococcus aureus Contamination of Environmental Surfaces in Households with Children Infected with Methicillin-Resistant S. aureus

    PubMed Central

    Fritz, Stephanie A.; Hogan, Patrick G.; Singh, Lauren N.; Thompson, Ryley M.; Wallace, Meghan A.; Whitney, Krista; Al-Zubeidi, Duha; Burnham, Carey-Ann D.; Fraser, Victoria J.

    2014-01-01

    IMPORTANCE Household environmental surfaces may serve as vectors for acquisition and spread of methicillin-resistant Staphylococcus aureus (MRSA) among household members, though few studies have evaluated which objects are important MRSA reservoirs. OBJECTIVES Determine the prevalence of environmental MRSA contamination in households of children with MRSA infection; define the molecular epidemiology of environmental, pet, and human MRSA strains within households; and identify factors associated with household MRSA contamination. DESIGN, SETTING, AND PARTICIPANTS Fifty households of children with active or recent culture-positive community-associated MRSA infection were enrolled from 2012–13 at St. Louis Children’s Hospital and community pediatric practices affiliated with the Washington University Pediatric and Adolescent Ambulatory Research Consortium. MAIN OUTCOMES AND MEASURES Participants’ nares, axillae, and inguinal folds were cultured to detect S. aureus colonization. Twenty-one environmental surfaces and pet dogs and cats were cultured. Molecular typing of S. aureus strains was performed by repetitive-sequence polymerase chain reaction to determine strain relatedness within households. RESULTS MRSA was recovered from environmental surfaces in 23 (46%) households, most frequently from the participant’s bed linens (18%), television remote control (16%), and bathroom hand towel (15%). MRSA colonized 12% of dogs and 7% of cats. At least 1 surface was contaminated with a strain type matching the participant’s isolate in 20 (40%) households. Participants colonized with S. aureus had a higher proportion of MRSA-contaminated surfaces (0.15 ± 0.17) than non-colonized participants [0.03± 0.06; mean difference 0.12 (95% CI 0.05, 0.20)]. A greater number of individuals per 1000 ft2 was also associated with a higher proportion of MRSA-contaminated surfaces (β=0.34, p=0.03). The frequency of cleaning household surfaces was not associated with S. aureus

  1. The Epidemiology of Methicillin-Resistant Staphylococcus aureus in Orthopaedics.

    PubMed

    Atkinson Smith, Mary

    2015-01-01

    In the specialty of orthopaedics, methicillin-resistant Staphylococcus aureus (MRSA) is a major contributor to infections of the soft tissues, surgical sites, and joints, in addition to increasing disability, mortality, and healthcare costs. Inappropriate prescribing and misuse of antibiotics have led to bacterial resistance and the rapid emergence of MRSA. It is imperative for healthcare providers and facilities to improve quality, promote safety, and decrease costs related to MRSA infections. The healthcare profession and society as a whole play an important role in minimizing the transmission of pathogens, reducing the incidence of MRSA infections, and decreasing the development of future antibiotic resistant pathogens. This article discusses the epidemiology of MRSA and describes evidence-based guidelines pertaining to the prevention, minimization, and treatment of MRSA-related infections. Specific application to orthopaedics are discussed in the context of patient risk factors, perioperative and postoperative prophylaxis, and current trends regarding education and reporting strategies.

  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…

  3. Quantification of Methicillin-Resistant Staphylococcus aureus Strains in Marine and Freshwater Samples by the Most-Probable-Number Method ▿

    PubMed Central

    Levin-Edens, Emily; Meschke, John Scott; Roberts, Marilyn C.

    2011-01-01

    Recreational beach environments have been recently identified as a potential reservoir for methicillin-resistant Staphylococcus aureus (MRSA); however, accurate quantification methods are needed for the development of risk assessments. This novel most-probable-number approach for MRSA quantification offers improved sensitivity and specificity by combining broth enrichment with MRSA-specific chromogenic agar. PMID:21441335

  4. 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.

  5. 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.

  6. Costs and benefits of the MRSA Search and Destroy policy in a Dutch hospital.

    PubMed

    van Rijen, M M L; Kluytmans, J A J W

    2009-10-01

    The objective of this study was to determine the costs and benefits of the MRSA Search and Destroy policy in a Dutch hospital during 2001 through 2006. Variable costs included costs for isolation, contact tracing, treatment of carriers and closure of wards. Fixed costs were the costs for the building of isolation rooms and the salary of one full-time infection control practitioner. To determine the benefits of the Search and Destroy policy, the transmission rate during the study period was calculated. Furthermore, the number of cases of meticillin-resistant Staphylococcus aureus (MRSA) bacteraemia prevented was estimated, as well as its associated prevented costs and patient lives. The costs of the MRSA policy were estimated to be euro 215,559 a year, which equals euro 5.54 per admission. The daily isolation costs for MRSA-suspected and -positive hospitalised patients were euro 95.59 and euro 436.62, respectively. Application of the Search and Destroy policy resulted in a transmission rate of 0.30 and was estimated to prevent 36 cases of MRSA bacteraemia per year, resulting in annual savings of euro 427,356 for the hospital and ten lives per year (95% confidence interval [CI] 8-14). In conclusion, application of the MRSA Search and Destroy policy in a hospital in a country with a low endemic MRSA incidence saves money and lives.

  7. 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

  8. 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.

  9. A Comparison of Clinical Features between Community-Associated and Healthcare-Associated Methicillin-Resistant Staphylococcus aureus Keratitis

    PubMed Central

    Ong, Sherine Jue; Chuang, Chih-Chun; Ma, David H. K.; Huang, Yhu-Chering

    2015-01-01

    Purpose. To compare the clinical features of community-associated (CA) and healthcare-associated (HA) methicillin-resistant Staphylococcus aureus (MRSA) keratitis. Methods. Patients presenting with culture-proven MRSA keratitis between January 1, 2006, and December 31, 2010, at Chang Gung Memorial Hospital, Taiwan, were included in this study. The patients' demographic and clinical information were reviewed retrospectively. Antibiotic susceptibility was verified using the disk diffusion method. Results. Information on 26 patients with MRSA keratitis was collected, including 12 cases of CA-MRSA and 14 cases of HA-MRSA. All MRSA isolates were susceptible to vancomycin; the only difference in drug susceptibility was that CA-MRSA isolates were more susceptible to trimethoprim/sulfamethoxazole than HA-MRSA (P = .034). The most common risk factor for MRSA keratitis was ocular surface disease. No significant differences were observed between the 2 groups in terms of clinical features, treatments, and visual outcomes. Conclusion. In Taiwan, CA-MRSA rivals HA-MRSA as a critical cause of MRSA keratitis. Furthermore, CA-MRSA isolates are multidrug resistant. CA-MRSA and HA-MRSA keratitis are clinically indistinguishable, although larger studies are warranted to further evaluate this association. PMID:25653870

  10. Monoclonal Antibody Targeting Staphylococcus aureus Surface Protein A (SasA) Protect Against Staphylococcus aureus Sepsis and Peritonitis in Mice

    PubMed Central

    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

  11. 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.

  12. 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...

  13. Wall teichoic acids mediate increased virulence in Staphylococcus aureus.

    PubMed

    Wanner, Stefanie; Schade, Jessica; Keinhörster, Daniela; Weller, Nicola; George, Shilpa E; Kull, Larissa; Bauer, Jochen; Grau, Timo; Winstel, Volker; Stoy, Henriette; Kretschmer, Dorothee; Kolata, Julia; Wolz, Christiane; Bröker, Barbara M; Weidenmaier, Christopher

    2017-01-23

    Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) are the cause of a severe pandemic consisting primarily of skin and soft tissue infections. The underlying pathomechanisms have not been fully understood and we report here a mechanism that plays an important role for the elevated virulence of CA-MRSA. Surprisingly, skin abscess induction in an animal model was correlated with the amount of a major cell wall component of S. aureus, termed wall teichoic acid (WTA). CA-MRSA exhibited increased cell-wall-associated WTA content (WTA(high)) and thus were more active in inducing abscess formation via a WTA-dependent and T-cell-mediated mechanism than S. aureus strains with a WTA(low) phenotype. We show here that WTA is directly involved in S. aureus strain-specific virulence and provide insight into the underlying molecular mechanisms that could guide the development of novel anti-infective strategies.

  14. 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

  15. Methicillin-resistant Staphylococcus aureus: an emerging pathogen of pets in Egypt with a public health burden.

    PubMed

    Abdel-moein, K A; El-Hariri, M; Samir, A

    2012-08-01

    Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) has emerged to be a pathogen of public health burden causing infections with significant concern. This study was conducted to investigate methicillin-resistant Staphylococcus aureus (MRSA) infection in pet dogs and cats as an emerging zoonosis that could be disseminated in the community. A total of 184 (nasal, oral, ear and wound) swabs were collected from 70 pet dogs and 48 pet cats, whereas 50 nasal and oral swabs were collected from 28 apparently healthy companion persons in intimate contact with pets and without history of hospitalization. All samples were cultured for the isolation and identification of Staphylococcus aureus using selective media, biochemical and serological tests, while isolates were identified as MRSA after antimicrobial susceptibility testing and determination of the MIC. PCR was applied using specific primers to confirm MRSA. Three MRSA isolates have been recovered from two dogs of 70 (2.9%) and one isolate from 28 examined persons (3.6%), while none of the examined cats yielded MRSA. Furthermore, we found that two MRSA isolates recovered from one diseased dog seemed to be hospital-associated methicillin-resistant Staphylococcus aureus (HA-MRSA), whereas the other dog isolate as well as the human isolate were considered as community-acquired (CA-MRSA). The occurrence of MRSA in apparently healthy and/or diseased pet dogs makes it an emerging veterinary pathogen which could be considered a public health burden if it is disseminated in our community outside hospitals.

  16. Carriage of Staphylococcus aureus in Thika Level 5 Hospital, Kenya: a cross-sectional study

    PubMed Central

    2014-01-01

    Background Methicillin-resistant Staphylococcus aureus (MRSA) is an important nosocomial pathogen but little is known about its circulation in hospitals in developing countries. We aimed to describe carriage of S.aureus amongst inpatients in a mid-sized Kenyan government hospital. Methods We determined the frequency of S.aureus and MRSA carriage amongst inpatients in Thika Hospital, Kenya by means of repeated cross-sectional ward surveys. For all S.aureus isolates, we performed antibiotic susceptibility tests, genomic profiling using a DNA microarray and spa typing and MLST. Results In this typical mid-sized Kenyan Government hospital, we performed 950 screens for current carriage of S.aureus amongst inpatients over a four month period. We detected S.aureus carriage (either MSSA or MRSA) in 8.9% (85/950; 95%CI 7.1-10.8) of inpatient screens, but patients with multiple screens were more likely have detection of carriage. MRSA carriage was rare amongst S.aureus strains carried by hospital inpatients – only 7.0% (6/86; 95%CI 1.5-12.5%) of all isolates were MRSA. Most MRSA (5/6) were obtained from burns patients with prolonged admissions, who only represented a small proportion of the inpatient population. All MRSA strains were of the same clone (MLST ST239; spa type t037) with concurrent resistance to multiple antibiotic classes. MSSA isolates were diverse and rarely expressed antibiotic resistance except against benzyl-penicillin and co-trimoxazole. Conclusions Although carriage rates for S.aureus and the MRSA prevalence in this Kenyan hospital were both low, burns patient were identified as a high risk group for carriage. The high frequency of genetically indistinguishable isolates suggests that there was local transmission of both MRSA and MSSA. PMID:25057351

  17. 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

  18. Evaluation of ceftiofur and cefquinome for phenotypic detection of methicillin resistance in Staphylococcus aureus using disk diffusion testing and MIC-determinations.

    PubMed

    Aarestrup, Frank M; Skov, Robert L

    2010-01-06

    Methicillin-resistant Staphylococcus aureus (MRSA) have emerged in animals. Testing 98 mecA negative and 71 mecA positive S. aureus we compared the usefulness of ceftiofur and cefquinome to cefoxitin, for detection of MRSA and found that these cephalosporins are not as efficient as cefoxitin.

  19. Silver resistance in MRSA isolated from wound and nasal sources in humans and animals.

    PubMed

    Loh, Jia V; Percival, Steven L; Woods, Emma J; Williams, Nicola J; Cochrane, Christine A

    2009-02-01

    Methicillin-resistant Staphylococcus aureus (MRSA) colonises skin, nasal passages and dermal wounds. Methods used to manage wounds infected and colonised with MRSA often include the use of topical antiseptics such as ionic silver and iodine. The objectives of this study were to determine the prevalence of silver-resistance (sil) genes in MRSA and methicillin-resistant coagulase-negative staphylococci (MR-CNS) isolated from wounds and nasal cavities of humans and animals, and also to determine the susceptibility of sil-positive and sil-negative MRSA isolates to a silver-containing Hydrofiber (SCH) wound dressing, on planktonic silE-positive and silE-negative MRSA. Polymerase chain reaction was used to determine the presence of three silver-resistance (sil) genes, silE, silP and silS in 33 MRSA and 8 methicillin-resistant staphylococci (MR-CNS). SilP and silS genes were absent in all isolates tested; however, two MRSA strains were found to contain the silE gene, together with one isolate of MR-CNS. Phenotypic resistance of the silE-positive strains and their susceptibility to the SCH dressing was evaluated using the zone of inhibition test on Mueller Hinton agar, and confocal laser microscopy using a live/dead fluorescent stain. Results confirmed that the SCH dressing was effective in killing all MRSA strains with and without the silE gene. First, this study showed that the prevalence of sil genes was low in the isolates investigated; and secondly, that the presence of a silver-resistance gene (silE) in MRSA and MR-CNS did not afford protection to the organism in the presence of a SCH wound dressing. The use of topical antiseptics in chronic wound care should be considered before the use of antibiotics that can result in their overuse and the risk of further resistance.

  20. 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

  1. Investigation of gaseous ozone for MRSA decontamination of hospital side-rooms.

    PubMed

    Berrington, A W; Pedler, S J

    1998-09-01

    A domestic, gaseous ozone generator was investigated for use in the decontamination of hospital side-rooms that have housed patients colonized with methicillin-resistant Staphylococcus aureus (MRSA). Three models of bacterial contamination were used. These were exposed to ozone generation in a standard hospital side-room for 4 and 7 h. A methicillin-sensitive and a methicillin-resistant strain of S. aureus were compared. Ozone concentrations of 0.14 ppm were reached, levels which are sufficient to cause mild pulmonary toxicity. Bacterial counts were reduced in the vicinity of the gas generator in most instances, but the effect elsewhere in the room was, at best, limited. MRSA appeared more resistant to the effects of ozone than methicillin-sensitive S. aureus. We conclude that the device tested would be inadequate for the decontamination of such hospital side-rooms.

  2. Genomic information on multidrug-resistant livestock-associated methicillin-resistant Staphylococcus aureus ST398 isolated from a Brazilian patient with cystic fibrosis

    PubMed Central

    Lima, Danielle F; Cohen, Renata WF; Rocha, Géssica A; Albano, Rodolpho M; Marques, Elizabeth A; Leão, Robson S

    2017-01-01

    Alarmingly, the isolation of methicillin-resistant Staphylococcus aureus (MRSA) has been increasing among patients with cystic fibrosis (CF). During a previous molecular characterisation of MRSA isolates obtained from patients with CF from Rio de Janeiro, Brazil, one isolate was identified as the ST398 clone, a livestock-associated (LA) MRSA. In this study, we report the draft genome sequence of an LA-MRSA ST398 clone isolated from a patient with CF. PMID:28076471

  3. Genomic information on multidrug-resistant livestock-associated methicillin-resistant Staphylococcus aureus ST398 isolated from a Brazilian patient with cystic fibrosis.

    PubMed

    Lima, Danielle F; Cohen, Renata Wf; Rocha, Géssica A; Albano, Rodolpho M; Marques, Elizabeth A; Leão, Robson S

    2017-01-01

    Alarmingly, the isolation of methicillin-resistant Staphylococcus aureus (MRSA) has been increasing among patients with cystic fibrosis (CF). During a previous molecular characterisation of MRSA isolates obtained from patients with CF from Rio de Janeiro, Brazil, one isolate was identified as the ST398 clone, a livestock-associated (LA) MRSA. In this study, we report the draft genome sequence of an LA-MRSA ST398 clone isolated from a patient with CF.

  4. Microbial Susceptibility and Plasmid Profiles of Methicillin-Resistant Staphylococcus aureus and Methicillin-Susceptible S. aureus

    PubMed Central

    Shahkarami, Fatemeh; Rashki, Ahmad; Rashki Ghalehnoo, Zahra

    2014-01-01

    Background: Today, significant increase in the prevalence and emergence of methicillin-resistant Staphylococcus aureus (MRSA) is a serious public health concern and is likely to have a dramatic negative impact on many current medical practices. Therefore, identification of MRSA strains is important for both clinical and epidemiological implications. Objectives: The present study was carried out to determine the frequency of methicillin resistant; antibiotic susceptibility and plasmid profiles of S. aureus recovered from different types of clinical samples of patients in Zabol, Iran. Material and Methods: Clinical samples from 500 outpatient and hospitalized patients were tested for S. aureus. The susceptibility of 106 S. aureus to 11 antibiotics was evaluated by the disk diffusion method and Etest oxacillin strips. The presence of mecA gene was investigated by polymerase chain reaction (PCR). The plasmid profile patterns of all isolates were determined by a modified alkaline lysis method. Results: A total of 67 (63.20%) strains were found to be MRSA isolates. Most of MRSA isolates showed high level of resistance to ampicillin, erythromycin, nalidixic acid, penicillin, and tetracycline. Twenty-six percent of MRSA isolates showed high level of resistance to oxacillin (minimum inhibitory concentration [MIC] ≥ 256 μg/mL). mecA gene was detected among 62 MRSA isolates. Totally, 75 isolates of both strains harbored plasmid. Conclusions: Resistance to oxacillin and other antibiotics was high, and most of the isolates were found to be multi-drug resistance (MDR). Plasmid analysis of representative S. aureus isolates also demonstrates the presence of a wide range of plasmid sizes, with no consistent relationship between plasmid profiles and resistance phenotypes. Regular surveillance of hospital infections and monitoring of their antibiotic sensitivity patterns are required to reduce MRSA prevalence. High prevalence and multi-drug resistance of MRSA isolates in southeast

  5. Antimicrobial resistance pattern of methicillin-resistant Staphylococcus aureus in the food industry.

    PubMed

    Paludi, D; Vergara, A; Festino, A R; Di Ciccio, P; Costanzo, C; Conter, M; Zanardi, E; Ghidini, S; Ianieri, A

    2011-01-01

    There is increasing concern about the impact on public health of methicillin-resistant Staphylococcus aureus (MRSA) associated with animal food products. MRSA remains a serious problem because of the high incidence and multidrug resistance of the strains, even for strains isolated from foods, food environments and food handlers. The objectives of this study are: (i) to evaluate the susceptibility of S. aureus strains isolated from food, food handlers and food-processing environments to 14 antibiotics currently used in veterinary and human therapy; (ii) to assess the presence of the mecA gene. A total of 1007 samples were collected from food, food handlers, and environments and were analyzed for the presence of S. aureus. S. aureus was present in 165 of the 1007 samples. A total of 157 isolates were methicillin-susceptible S. aureus (MSSA) and 8 isolates were MRSA. In particular, out of 8 MRSA strains detected, 4 strains harboured the mecA gene. All MRSA strains were resistant to at least one of the tested antibiotics and 6 strains demonstrated multi-resistance. Considering the high level of resistances in S. aureus and the isolation of MRSA strains, the surveillance of antimicrobial resistance and the spreading of this pathogen is of crucial importance in the food production chain. These data are useful in improving background data on antimicrobial resistance of S. aureus isolated from food, processing environments and food handlers, supporting the prudent use of antibiotics and the development of international control programs.

  6. Methicillin-resistant Staphylococcus aureus carriage among veterinary staff and dogs in private veterinary clinics in Hokkaido, Japan.

    PubMed

    Ishihara, Kanako; Saito, Mieko; Shimokubo, Natsumi; Muramatsu, Yasukazu; Maetani, Shigeki; Tamura, Yutaka

    2014-03-01

    To explore the prevalence and molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) in veterinary medical practices, MRSA carriage was tested among 96 veterinarians (Vets), 70 veterinary technicians (VTs) and 292 dogs with which they had contact at 71 private veterinary clinics (VCs) in Hokkaido, Japan. MRSA isolates were obtained from 22 Vets [22.9%] and 7 VTs [10%]. The prevalence of MRSA among Vets was as high as that found in an academic veterinary hospital in our previous study. In contrast, only two blood donor dogs and one dog with liver disease (1.0%, 3/292) yielded MRSA. All MRSA-positive dogs were reared or treated in different VCs, in each of which at least one veterinary staff member carrying MRSA worked. Sequence types (ST) identified by multilocus sequence typing, spa types, and SCCmec types for canine MRSA isolates (ST5-spa t002-SCCmec II [from two dogs] or ST30-spa t021-SCCmec IV [from a dog]) were concordant with those from veterinary staff members in the same clinics as the MRSA-positive dogs, with which they had potentially had contact. Most MRSA isolates from veterinary staff were the same genotype (SCCmec type II and spa type t002) as a major hospital-acquired MRSA clone in Japan. The remaining MRSA was the same genotypes as domestic and foreign community-associated MRSA. Measures against MRSA infection should be provided in private VCs.

  7. Direct Detection of Staphylococcus Osteoarticular Infections by Use of Xpert MRSA/SA SSTI Real-Time PCR ▿

    PubMed Central

    Dubouix-Bourandy, Anne; de Ladoucette, Aymard; Pietri, Valerie; Mehdi, Nazim; Benzaquen, David; Guinand, Régis; Gandois, Jean-Marc

    2011-01-01

    We evaluated the Xpert MRSA/SA SSTI real-time PCR assay (Cepheid, Sunnyvale, CA) directly on perioperative bone and joint samples. The sensitivity and specificity for detection of methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant Staphylococcus aureus (MRSA), and methicillin-resistant coagulase-negative Staphylococcus were, respectively, 100% and 98.3%, 100% and 100%, and 100% and 95.3%. The median total test turnaround time was 72 min for PCR versus 79 h for culture. Using these rapid results, appropriate antibiotic treatment could be rapidly initiated. PMID:21998420

  8. Molecular Epidemiology of Staphylococcus aureus in the General Population in Northeast Germany: Results of the Study of Health in Pomerania (SHIP-TREND-0)

    PubMed Central

    Holtfreter, Silva; Grumann, Dorothee; Balau, Veronika; Barwich, Annette; Kolata, Julia; Goehler, André; Weiss, Stefan; Holtfreter, Birte; Bauerfeind, Stephanie S.; Döring, Paula; Friebe, Erika; Haasler, Nicole; Henselin, Kristin; Kühn, Katrin; Nowotny, Sophie; Radke, Dörte; Schulz, Katrin; Schulz, Sebastian R.; Trübe, Patricia; Vu, Chi Hai; Walther, Birgit; Westphal, Susanne; Cuny, Christiane; Witte, Wolfgang; Völzke, Henry; Grabe, Hans Jörgen; Kocher, Thomas; Steinmetz, Ivo

    2016-01-01

    Population-based studies on Staphylococcus aureus nasal colonization are scarce. We examined the prevalence, resistance, and molecular diversity of S. aureus in the general population in Northeast Germany. Nasal swabs were obtained from 3,891 adults in the large-scale population-based Study of Health in Pomerania (SHIP-TREND). Isolates were characterized using spa genotyping, as well as antibiotic resistance and virulence gene profiling. We observed an S. aureus prevalence of 27.2%. Nasal S. aureus carriage was associated with male sex and inversely correlated with age. Methicillin-resistant S. aureus (MRSA) accounted for 0.95% of the colonizing S. aureus strains. MRSA carriage was associated with frequent visits to hospitals, nursing homes, or retirement homes within the previous 24 months. All MRSA strains were resistant to multiple antibiotics. Most MRSA isolates belonged to the pandemic European hospital-acquired MRSA sequence type 22 (HA-MRSA-ST22) lineage. We also detected one livestock-associated MRSA ST398 (LA-MRSA-ST398) isolate, as well as six livestock-associated methicillin-susceptible S. aureus (LA-MSSA) isolates (clonal complex 1 [CC1], CC97, and CC398). spa typing revealed a diverse but also highly clonal S. aureus population structure. We identified a total of 357 spa types, which were grouped into 30 CCs or sequence types. The major seven CCs (CC30, CC45, CC15, CC8, CC7, CC22, and CC25) included 75% of all isolates. Virulence gene patterns were strongly linked to the clonal background. In conclusion, MSSA and MRSA prevalences and the molecular diversity of S. aureus in Northeast Germany are consistent with those of other European countries. The detection of HA-MRSA and LA-MRSA within the general population indicates possible transmission from hospitals and livestock, respectively, and should be closely monitored. PMID:27605711

  9. Detection and molecular characterization of Livestock-Associated MRSA in raw meat on retail sale in North West England.

    PubMed

    Fox, A; Pichon, B; Wilkinson, H; Doumith, M; Hill, R L R; McLauchlin, J; Kearns, A M

    2017-03-01

    Limited data are available on the prevalence of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in the UK. We tested 124 raw meat samples for MRSA including pork (n = 63), chicken (n = 50) and turkey (n = 11) collected from retail outlets in North West England between March and July 2015. MRSA was recovered from nine (7·3%) samples (four chicken, three pork and two turkey) from different butchers and supermarkets. Four were labelled of UK origin, three were from continental Europe; the origin was not specified for two samples. Whole-genome sequencing (WGS), spa typing and the presence of lineage-specific canonical single nucleotide polymorphisms confirmed that they belonged to the livestock-associated clade of clonal complex (CC) 398. Seven (77·8%) isolates were multi-drug resistant. Phylogenetic analyses showed the isolates were diverse, suggesting multiple silent introductions of LA-MRSA into the UK food chain. Two chicken meat isolates belonged to a sub-clade recently reported from human cases in Europe where poultry meat was the probable source. The low levels of MRSA identified (<20 CFU per g) and absence of enterotoxin genes suggest the risk of acquisition of, or food-poisoning due to, LA-MRSA is low. Nevertheless, the MRSA contamination rate is higher than previously estimated; further evaluation of the public health impacts of LA-MRSA is warranted.

  10. The Effect of Universal Decolonization With Screening in Critical Care to Reduce MRSA Across an Entire Hospital.

    PubMed

    Bradley, Craig W; Wilkinson, Martyn A C; Garvey, Mark I

    2017-02-06

    OBJECTIVE To describe the effect of universal methicillin-resistant Staphylococcus aureus (MRSA) decolonization therapy in a large intensive care unit (ICU) on the rates of MRSA cases and acquisitions in a UK hospital. DESIGN Descriptive study. SETTING University Hospitals Birmingham (UHB) NHS Foundation Trust is a tertiary referral teaching hospital in Birmingham, United Kingdom, that provides clinical services to nearly 1 million patients every year. METHODS A break-point time series analysis and kernel regression models were used to detect significant changes in the cumulative monthly numbers of MRSA bacteremia cases and acquisitions from April 2013 to August 2016 across the UHB system. RESULTS Prior to 2014, all ICU patients at UHB received universal MRSA decolonization therapy. In August 2014, UHB discontinued the use of universal decolonization due to published reports in the United Kingdom detailing the limited usefulness and cost-effectiveness of such an intervention. Break-point time series analysis of MRSA acquisition and bacteremia data indicated that break points were associated with the discontinuation and subsequent reintroduction of universal decolonization. Kernel regression models indicated a significant increase (P<.001) in MRSA acquisitions and bacteremia cases across UHB during the period without universal decolonization. CONCLUSION We suggest that routine decolonization for MRSA in a large ICU setting is an effective strategy to reduce the spread and incidence of MRSA across the whole hospital. Infect Control Hosp Epidemiol 2017:1-6.

  11. 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.

  12. 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...

  13. 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…

  14. 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...

  15. Transmission rates, screening methods and costs of MRSA--a systematic literature review related to the prevalence in Germany.

    PubMed

    Tübbicke, A; Hübner, C; Kramer, A; Hübner, N-O; Fleßa, S

    2012-10-01

    Methicillin-resistant Staphylococcus aureus (MRSA) infections represent a serious challenge for health care institutions, which is inherent in the combination of prevalence, transmission rates and costs. Furthermore, performing an MRSA screening requires information on the complex system of effectiveness, accuracy and costs of different screening methods. The purpose of this study was to give an overview of parameters with decisive significance for the burden of MRSA and the selection of a specific MRSA screening strategy. A systematic literature search for peer-reviewed health economic studies associated with MRSA was performed (from 1995 to the present). Eighty-seven different studies met all inclusion and exclusion criteria. Primary outcomes included the prevalence of MRSA, MRSA transmission rates, performance characteristics of MRSA screening methods, costs for pre-emptive isolation precautions and costs per MRSA case. The prevalence rates reported for all inpatients (1.2-5.3 %) as well as for inpatients with risk factors or patients in risk areas (3.85-20.6 %) vary greatly. The range of cross-transmission rates per day reported for patients with MRSA in isolation is 0.00081-0.009 and for carriers not in isolation is 0.00137-0.140, respectively. For polymerase chain reaction (PCR) methods, the mean sensitivity and specificity were 91.09 and 95.79 %, respectively. Culture methods show an average sensitivity of 89.01 % and an average specificity of 93.21 %. The turn-around time for PCR methods averages 15 h, while for the culture method, it can only be estimated as 48-72 h. This review filtered important parameters and cost drivers, and covered them with literature-based averages. These findings serve as an ideal evidence base for further health economic considerations of the cost-effectiveness of different MRSA screening methods.

  16. Hyperimmunoglobulin E syndrome with persistent vertebral osteomyelitis due to methicillin-resistant Staphylococcus aureus

    PubMed Central

    Wong, San S.; Smith, Peter R.; Ayaz, Asim; Sepkowitz, Douglas

    2014-01-01

    We report a case of vertebral osteomyelitis due to methicillin-resistant Staphylococcus aureus (MRSA) with a slowly progressive, relatively asymptomatic course in a young woman with suspected hyperimmunoglobulin E syndrome (Job's syndrome). PMID:26839768

  17. 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.

  18. Methicillin-resistant Staphylococcus aureus isolates in a hospital of Shanghai

    PubMed Central

    Wang, Xiaoguang; Ouyang, Lin; Luo, Lingfei; Liu, Jiqian; Song, Chiping; Li, Cuizhen; Yan, Hongjing; Wang, Ping

    2017-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) strains are now common both in the health care setting and in the community. Active surveillance is critical for MRSA control and prevention. Specimens of patients (200 patients with 1119 specimens) as well as medical staff and hospital setting (1000 specimens) were randomly sampled in a level 2 hospital in Shanghai from September 2011 to August 2012. Isolation, cultivation and identification of S. aureus were performed. Totally, 67 S. aureus strains were isolated. 32 S. aureus strains were isolated from patient samples; 13 (13/32, 40.6%) of the 32 S. aureus isolates were MRSA; sputum sample and patients in the department of general internal medicine were the most frequent specimen and patient group for S. aureus strains isolation. Remaining 35 S. aureus strains were isolated from the medical staff and hospital setting; 20 (20/35, 57.1%) of the 35 S. aureus isolates were MRSA; specimens sampled from doctors and nurses’ hands and nose and hospital facilities were the most frequent samples to isolate S. aureus. Resistant and virulent genes detection showed that, all 33 MRSA strains were mecA positive which accounts for 49.3% of the 67 S. aureus strains; 38 isolates were Panton-Valentine leukocidin (PVL) gene positive which accounts for 56.7% of the 67 S. aureus strains; and 17 (17/67, 25.4%) isolates are mecA and PVL genes dual positive. Multidrug-resistant strains of MRSA and PVL positive S. aureus are common in patients, medical staff and hospital setting, the potential health threat is worthy of our attention. PMID:28030828

  19. Methicillin-resistant staphylococcus aureus isolates in a hospital of shanghai.

    PubMed

    Wang, Xiaoguang; Ouyang, Lin; Luo, Lingfei; Liu, Jiqian; Song, Chiping; Li, Cuizhen; Yan, Hongjing; Wang, Ping

    2017-01-24

    Methicillin-resistant Staphylococcus aureus (MRSA) strains are now common both in the health care setting and in the community. Active surveillance is critical for MRSA control and prevention. Specimens of patients (200 patients with 1119 specimens) as well as medical staff and hospital setting (1000 specimens) were randomly sampled in a level 2 hospital in Shanghai from September 2011 to August 2012. Isolation, cultivation and identification of S. aureus were performed. Totally, 67 S. aureus strains were isolated. 32 S. aureus strains were isolated from patient samples; 13 (13/32, 40.6%) of the 32 S. aureus isolates were MRSA; sputum sample and patients in the department of general internal medicine were the most frequent specimen and patient group for S. aureus strains isolation. Remaining 35 S. aureus strains were isolated from the medical staff and hospital setting; 20 (20/35, 57.1%) of the 35 S. aureus isolates were MRSA; specimens sampled from doctors and nurses' hands and nose and hospital facilities were the most frequent samples to isolate S. aureus. Resistant and virulent genes detection showed that, all 33 MRSA strains were mecA positive which accounts for 49.3% of the 67 S. aureus strains; 38 isolates were Panton-Valentine leukocidin (PVL) gene positive which accounts for 56.7% of the 67 S. aureus strains; and 17 (17/67, 25.4%) isolates are mecA and PVL genes dual positive. Multidrug-resistant strains of MRSA and PVL positive S. aureus are common in patients, medical staff and hospital setting, the potential health threat is worthy of our attention.

  20. 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

  1. Harnessing the power of light to treat staphylococcal infections focusing on MRSA.

    PubMed

    Agrawal, Tanupriya; Avci, Pinar; Gupta, Gaurav K; Rineh, Ardeshir; Lakshmanan, Shanmugamurthy; Batwala, Vincent; Tegos, George P; Hamblin, Michael R

    2015-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) has become the most important drug-resistant microbial pathogen in countries throughout the world. Morbidity and mortality due to MRSA infections continue to increase despite efforts to improve infection control measures and to develop new antibiotics. Therefore alternative antimicrobial strategies that do not give rise to development of resistance are urgently required. A group of therapeutic interventions has been developed in the field of photomedicine with the common theme that they rely on electromagnetic radiation with wavelengths between 200 and 1000 nm broadly called "light". These techniques all use simple absorption of photons by specific chromophores to deliver the killing blow to microbial cells while leaving the surrounding host mammalian cells relatively unharmed. Photodynamic inactivation uses dyes called photosensitizers (PS) that bind specifically to MRSA cells and not host cells, and generate reactive oxygen species including singlet oxygen and singlet oxygen upon illumination. Sophisticated molecular strategies to target the PS to MRSA cells have been designed. Ultraviolet C radiation can damage microbial DNA without unduly harming host DNA. Blue light can excite endogenous porphyrins and flavins in MRSA cells that are not present in host cells. Near-infrared lasers can interfere with microbial membrane potentials without raising the temperature of the tissue. Taken together these innovative approaches towards harnessing the power of light suggest that the ongoing threat of MRSA may eventually be defeated.

  2. Is tea tree oil effective at eradicating MRSA colonization? A review.

    PubMed

    Flaxman, Deborah; Griffiths, Peter

    2005-03-01

    In vitro studies show that tea tree oil is capable of killing methicillin-resistant Staphylococcus aureus (MRSA) in a laboratory setting. This review of randomized controlled trials (RCTs) was undertaken to find out whether it is effective at eradicating MRSA colonization compared to standard mupirocin-based regimens in colonized patients. A wide range of databases and internet sources were searched to identify published and unpublished studies. Two RCTs were found that researched the effectiveness of tea tree oil preparations against MRSA. One small RCT (n = 30) showed a large but non-significant improvement at eradicating MRSA compared to traditional treatment, whereas a larger study (n = 224) demonstrated little difference in rates of eradication overall (41% for tea tree and 49% for mupirocin, p = 0.286). However, the larger study found that those with nasal colonization receiving a tea tree regimen were more likely to remain colonized with MRSA in the nose (absolute risk increase 31%, p<0.001). Currently there is insufficient evidence to support the routine use of tea tree oil in clinical practice for eradication of MRSA colonization.

  3. Anti-MRSA cephems. Part 2: C-7 cinnamic acid derivatives.

    PubMed

    Springer, Dane M; Luh, Bing Yu; Goodrich, Jason; Bronson, Joanne J

    2003-01-17

    Forty-five novel cephalosporin derivatives with activity against methicillin-resistant Staphylococcus aureus (MRSA) are described. The compounds contain novel cinnamic acid moieties at C-7 that were synthesized using a key Heck reaction followed by nucleophilic aromatic substitution reactions. The most active compound (41) displayed an MIC(90) against MRSA of 1.0 microg/mL, and a PD(50) of 0.8 mg/kg. Compound 14 was found to be very safe in a mouse model of acute toxicity.

  4. 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

  5. Treatment options for nosocomial pneumonia due to MRSA.

    PubMed

    Niederman, Michael S

    2009-09-01

    Nosocomial pneumonia, which includes hospital-acquired pneumonia, ventilator-associated pneumonia, and health care associated pneumonia, remains an important cause of morbidity and mortality. The continuing emergence of methicillin-resistant Staphylococcus aureus (MRSA) as a nosocomial pneumonia pathogen is particularly problematic not only because of its prevalence, but also because antimicrobial resistance is increasingly associated with inappropriate empirical antibiotic therapy. As a result, intensivists are faced with the dual goals of providing initial accurate broad-spectrum antibiotic coverage to reduce mortality while minimizing the risk for the emergence of antimicrobial resistance. These competing goals can be achieved by using an approach that initially delivers liberal broad-spectrum coverage followed by de-escalation once culture results and serial clinical observations become available. In ventilator-associated pneumonia, linezolid has demonstrated favorable activity against Gram-positive bacteria, including MRSA, and is recommended in evidence-based guidelines as an alternative to vancomycin, particularly when MRSA is documented as the etiology.

  6. 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

  7. Molecular characteristics of methicillin-resistant Staphylococcus aureus blood isolates: clonal spread of staphylococcal cassette chromosome mec type IVA between the community and the hospital.

    PubMed

    Moon, Soo-Youn; Lee, Hee-Joo; Lee, Mi Suk

    2010-09-01

    Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) is becoming increasingly common worldwide. The purpose of this study was to identify the prevalence and molecular characteristics of MRSA bloodstream isolates in hospitals. Clinical data from patients with MRSA bacteremia between 2003 and 2005 were collected. Isolates were classified as hospital-acquired (HA-MRSA), health care-associated (HCA-MRSA), or CA-MRSA according to the time of isolation and the risk factors for colonization. Available strains were tested for the presence of mecA, staphylococcal cassette chromosome mec (SCCmec), and by multilocus sequence test. Among 129 cases, 78 nonduplicated isolates were analyzed. The proportion of CA-MRSA, HCA-MRSA, and HA-MRSA was 2.6% (2), 23.1% (18), and 74.4% (58), respectively. According to multilocus sequence test and SCCmec, there were seven genotypes with sequence types (STs) and SCCmec types. The predominant genotype, ST5-MRSA-II, was found in 57.7% (45). All type IVA isolates was ST72 (9), and ST72-MRSA-IVA was identified in CA-MRSA (2, 100%), HCA-MRSA (1, 5.6%), and HA-MRSA (6, 10.3%), respectively. In summary, CA-MRSA bacteremia was not common in our hospital during the period.

  8. 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

  9. Treatment of Methicillin-Resistant Staphylococcus aureus Bacteremia

    PubMed Central

    2016-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a significant cause of health care-associated infections. Vancomycin remains an acceptable treatment option. There has been a welcome increase in the number of agents available for the treatment of MRSA infection. These drugs have certain differentiating attributes and may offer some advantages over vancomycin, but they also have significant limitations. These agents provide some alternative when no other options are available. PMID:28032484

  10. Methicillin-Resistant Staphylococcus aureus Colonization and Risk of Subsequent Infection in Critically Ill Children: Importance of Preventing Nosocomial Methicillin-Resistant Staphylococcus aureus Transmission

    PubMed Central

    Goldner, Brian W.; Ross, Tracy; Shepard, John W.; Carroll, Karen C.

    2011-01-01

    Background. Methicillin-resistant Staphylococcus aureus (MRSA) colonization is a predictor of subsequent infection in hospitalized adults. The risk of subsequent MRSA infections in hospitalized children colonized with MRSA is unknown. Methods. Children admitted to an academic medical center’s pediatric intensive care unit between March 2007 and March 2010 were included in the study. Anterior naris swabs were cultured to identify children with MRSA colonization at admission. Laboratory databases were queried and National Healthcare Safety Network definitions applied to identify patients with MRSA infections during their hospitalization or after discharge. Results. The MRSA admission prevalence among 3140 children was 4.9%. Overall, 56 children (1.8%) developed an MRSA infection, including 13 (8.5%) colonized on admission and 43 (1.4%) not colonized on admission (relative risk [RR], 5.9; 95% confidence interval [CI], 3.4–10.1). Of those, 10 children (0.3%) developed an MRSA infection during their hospitalization, including 3 of 153 children (1.9%) colonized on admission and 7 of 2987 children (0.2%) not colonized on admission (RR, 8.4; 95% CI, 2.7–25.8). African-Americans and those with public health insurance were more likely to get a subsequent infection (P < .01 and P = .03, respectively). We found that 15 children acquired MRSA colonization in the pediatric intensive care unit, and 7 (47%) developed a subsequent MRSA infection. Conclusions. MRSA colonization is a risk factor for subsequent MRSA infection in children. Although MRSA colonized children may have lower risks of subsequent infection than adults, children who acquire MRSA in the hospital have similarly high rates of infection. Preventing transmission of MRSA in hospitalized children should remain a priority. PMID:21878424

  11. A phylogenomic framework for assessing the global emergence and evolution of clonal complex 398 methicillin-resistant Staphylococcus aureus

    PubMed Central

    Gonçalves da Silva, Anders; Baines, Sarah L.; Carter, Glen P.; Heffernan, Helen; French, Nigel P.; Ren, Xiaoyun; Seemann, Torsten; Bulach, Dieter; Kwong, Jason; Stinear, Timothy P.; Howden, Benjamin P.

    2017-01-01

    Distinct clones of methicillin-resistant Staphylococcus aureus (MRSA) have emerged as important causes of infection in individuals who have exposure to livestock (livestock-associated MRSA; LA-MRSA). Clonal complex 398 (CC398) is the most prevalent LA-MRSA clone, and has been reported from several geographical settings, including Europe, the Americas and Asia. To understand the factors contributing to the global dissemination of this clone, we analysed CC398 MRSA isolates from New Zealand (NZ), a geographically isolated country with an economy strongly dependent on livestock farming. We supplemented the NZ CC398 MRSA collection with global datasets of CC398 MRSA and CC398 methicillin-susceptible S. aureus. Here, we demonstrate multiple sporadic incursions of CC398 MRSA into NZ, as well as recent importation and spread of a swine-associated clade related to the European LA-MRSA lineage. Within a larger global phylogenomic framework, Bayesian modelling suggested that this NZ clade emerged in the late 2000s, with a probable origin in swine from Western Europe. Elucidating the factors responsible for the incursion and spread of LA-MRSA in geographically distant regions, such as NZ, provides important insights into global pathways of S. aureus transmission, and will inform strategies to control importation and spread. PMID:28348878

  12. Characteristics of methicillin resistant Staphylococcus aureus isolated from chicken meat and hospitalized dogs in Korea and their epidemiological relatedness.

    PubMed

    Kwon, Nam Hoon; Park, Kun Taek; Jung, Woo Kyung; Youn, Hwa Young; Lee, Yeonhee; Kim, So Hyun; Bae, Wonki; Lim, Ji Youn; Kim, Ji Yeon; Kim, Jun Man; Hong, Soon Keun; Park, Yong Ho

    2006-10-31

    Methicillin resistant Staphylococcus aureus (MRSA) is one of the most important pathogens in human and veterinary hospitals. The isolation of MRSA from animals and foodstuffs has been reported with an increased incidence. However, methicillin (oxacillin) is not used in animal husbandry or in animal hospitals in Korea. In this study, three pre-MRSA and one silent mecA-carrying methicillin susceptible S. aureus (smMSSA) were isolated from retail chicken meat, and three MRSA were isolated from hospitalized dogs in Korea. The three pre-MRSA isolates were determined to have a staphylococcal cassette chromosome mec (SCCmec) type III, and the smMSSA isolate was not classified. The animal hospital isolates were found to contain SCCmec type II. Seven and 15 S. aureus isolated from hospitalized humans and bovine milk, respectively, were also examined in this study in order to determine the epidemiological origins of MRSA. Multilocus sequencing typing (MLST) revealed that the chicken meat and bovine milk isolates were closely related to the animal hospital isolates. The SCCmec characteristics and MLST analyses indicated the possibility of the human to animal transmission of MRSA. These results highlight the importance of identifying MRSA carriers as well as intercepting MRSA transmission because MRSA is becoming increasingly widespread without any plausible relationship with the use of methicillin (oxacillin).

  13. Antimicrobial Photodynamic Therapy for Methicillin-Resistant Staphylococcus aureus Infection

    PubMed Central

    Fu, Xiu-jun; Fang, Yong; Yao, Min

    2013-01-01

    Nowadays methicillin-resistant Staphylococcus aureus (MRSA) is one of the most common multidrug resistant bacteria both in hospitals and in the community. In the last two decades, there has been growing concern about the increasing resistance to MRSA of the most potent antibiotic glycopeptides. MRSA infection poses a serious problem for physicians and their patients. Photosensitizer-mediated antimicrobial photodynamic therapy (PDT) appears to be a promising and innovative approach for treating multidrug resistant infection. In spite of encouraging reports of the use of antimicrobial PDT to inactivate MRSA in large in vitro studies, there are only few in vivo studies. Therefore, applying PDT in the clinic for MRSA infection is still a long way off. PMID:23555074

  14. [Effectiveness of alcoholic hand disinfectants against methicillin resistant Staphylococcus aureus].

    PubMed

    Kampf, G; Jarosch, R; Rüden, H

    1997-03-01

    In order to determine the efficacy of hand disinfectants based on alcohol against three MRSA strains and 3 methicillin-susceptible S. aureus strains (MSSA), 1-propanol (60%) as well as Sterillium and Spitaderm were investigated in the quantitative suspension test at various dilutions and reactions times (15, 30 and 60s). All undiluted disinfectants revealed reduction factors > 6 against MRSA and MSSA after 30s. Diluted disinfectants (50%) were significantly less effective against MRSA at short reaction times (15 s) (p < 0.05). Sterillium in a dilution of 50% did not reach 5 reduction factors against either MRSA or MSSA after 30 s. The impact of an appropriate use of hand disinfectants in order to break chains of infections with MRSA is obvious.

  15. Pharmacokinetics, pharmacodynamics and efficacy of novel FabI inhibitor AFN-1252 against MSSA and MRSA in the murine thigh infection model

    PubMed Central

    Banevicius, Mary A; Kaplan, Nachum; Hafkin, Barry; Nicolau, David P

    2013-01-01

    AFN-1252, a new antimicrobial agent, specifically and potently inhibits fatty acid synthesis in Staphylococcus aureus. We characterized in vivo pharmacokinetic and pharmacodynamic profiles of AFN-1252 administered orally to neutropenic mice inoculated in thighs (∼106 CFU) with methicillin-susceptible S. aureus (MSSA) ATCC 29213. Efficacy was also assessed in mice inoculated with MSSA, hospital-acquired Methicillin-resistant Staphylococcus aureus (HA-MRSA) or community-acquired (CA)-MRSA, and administered AFN-1252 or linezolid orally. Bacterial density was determined after 24 hours and efficacy defined as the change in CFU/thigh versus untreated controls at time 0. With MSSA, antibacterial reductions of ≧1 log were observed at ≧20 mg/kg doses, with ƒAUC/minimum inhibitory concentration (MIC) best describing the pharmacodynamic profile of AFN-1252. The 80, 50 and 5% maximum effects were observed with ƒAUC/MIC values of 22·3, 17·0, and 9·6, respectively. Similar values were obtained for CA-MRSA and HA-MRSA. AFN-1252 was 4–40 fold more effective than linezolid against CA-MRSA and HA-MRSA. These data demonstrate the excellent in vivo potency of AFN-1252 against phenotypically diverse S. aureus. PMID:23433441

  16. 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

  17. Prevalence and characterization of methicillin-resistant Staphylococcus aureus isolates from retail meat and humans in Georgia.

    PubMed

    Jackson, Charlene R; Davis, Johnnie A; Barrett, John B

    2013-04-01

    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.

  18. The distribution of pathogenic and toxigenic genes among MRSA and MSSA clinical isolates.

    PubMed

    Imani Fooladi, Abbas Ali; Ashrafi, Elnaz; Tazandareh, Shafie Gorbani; Koosha, Roohollah Zarei; Rad, Hamid Sedighian; Amin, Mohsen; Soori, Mina; Larki, Reza Abbasi; Choopani, Ali; Hosseini, Hamideh Mahmoodzadeh

    2015-04-01

    Staphylococcus aureus (S. aureus) is considered as a notorious nosocomial pathogen among hospitalized patients and community-dwelling subjects. Its increasing morbidity and mortality is believed to be due to antibiotic resistance. However, the data concerning molecular properties of infecting strains are few. In this study, a total of 192 S. aureus strains, including 88 (45.8%) meticillin-sensitive S. aureus (MSSA) and 104 (54.2%) meticillin-resistant S. aureus (MRSA) were recovered from clinical samples. The prevalence of subtypes containing staphylococcal cassette chromosome mec (SSCmec), staphylococcal enterotoxins (SEs), toxic shock syndrome toxin (TSST) and exfoliative toxin was assessed by PCR. Antibiotic susceptibility pattern and vancomycin resistance of each isolate were evaluated by disk diffusion method and micro-dilution method, respectively. 9 (2.3%) strains required MIC > 2 mg/l of vancomycin, which significantly increased among multi drug resistant (MDR), MRSA and SCCmec type III strains (p < 0.05). 171 (89%), 140 (72.91%), 7 (3.6), 78 (48.6%), 5 (2.6%), 151 (78.64%), 129 (67.18%), 178 (92.7%) and 15 (7.8%) of 192 isolates harbored mecA, entA, entB, entC, entD, entE, eta, etb and tsst-1 genes, respectively. 31 (16.14%), 5 (2.6%), 95 (49.48%) and 7 (3.64%) of 192 isolates carried SCCmec type I, II, III and IV, respectively. We found a significantly higher rate of MRSA and resistance to all tested antibiotics, except to penicillin G, kanamycin and linezolide among the SCCmec type III class (p < 0.05). According to our findings, MSSA isolates should be taken as seriously as MRSA strains due to the potential presence of broad spectrum virulence factor genes.

  19. [Cats and dogs as a reservoir for Staphylococcus aureus].

    PubMed

    Bierowiec, Karolina; Płoneczka-Janeczko, Katarzyna; Rypuła, Krzysztof

    2014-08-18

    For many years, Staphylococcus aureus MRSA was thought to happen only in humans. It has now become an increasingly urgent problem in veterinary medicine, with MRSA infections reported in pets as well as farm animals. The animals may be contaminated, colonized or infected with MSSA as well as MRSA strains. Pets are a potential reservoir for human infection. Transmission of such pathogen occurs between pets, owners and veterinary staff. This is why, is need to generate data regarding both the levels of carriage of such bacteria in pets and the risk factors associated with the transfer of the bacteria to humans, who have a contact with infected pets.

  20. Anthracimycin Activity Against Contemporary Methicillin-Resistant Staphylococcus aureus

    PubMed Central

    Hensler, Mary E.; Jang, Kyoung Hwa; Thienphrapa, Wdee; Vuong, Lisa; Tran, Dan N.; Soubih, Evaristus; Lin, Leo; Haste, Nina M.; Cunningham, Mark L.; Kwan, Bryan P.; Shaw, Karen Joy; Fenical, William; Nizet, Victor

    2014-01-01

    Anthracimycin is a recently discovered novel marine-derived compound with activity against Bacillus anthracis. We tested anthracimycin against an expanded panel of Staphylococcus aureus strains in vitro and in vivo. All strains of S. aureus tested, including methicillin-sensitive (MSSA), methicillin-resistant (MRSA), and vancomycin-resistant strains of S. aureus were sensitive to anthracimycin at minimum inhibitory concentrations (MIC) of < 0.25 mg/L. Although its post-antibiotic effects were minimal, anthracimycin exhibited potent and rapid bactericidal activity, with a > 4-log kill of USA300 MRSA within 3 hours at 5 times its MIC. At concentrations significantly below the MIC, anthracimycin slowed MRSA growth and potentiated the bactericidal activity of the human cathelicidin, LL-37. The bactericidal activity of anthracimycin was somewhat mitigated in the presence of 20% human serum, and the compound was minimally toxic to human cells, with an IC50 = 70 mg/L against human carcinoma cells. At concentrations near the MIC anthracimycin inhibited S. aureus nucleic acid synthesis as determined by optimized macromolecular synthesis methodology, with inhibition of DNA and RNA synthesis occurring in the absence of DNA intercalation. Anthracimycin at a single dose of 1 or 10 mg/kg was able to protect mice from MRSA-induced mortality in a murine peritonitis model of infection. Anthracimycin provides an interesting new scaffold for future development of a novel MRSA antibiotic. PMID:24736856

  1. Further investigation of inhibitors of MRSA pyruvate kinase: Towards the conception of novel antimicrobial agents.

    PubMed

    Labrière, Christophe; Gong, Huansheng; Finlay, B Brett; Reiner, Neil E; Young, Robert N

    2017-01-05

    Several novel series of compounds were synthesized and evaluated as inhibitors of methicillin-resistant Staphylococcus aureus (MRSA) pyruvate kinase (PK). PK has been identified as a highly interconnected essential 'hub' protein in MRSA, with structural features distinct from the human homologs which makes it a novel antimicrobial target. Several MRSA PK inhibitors (including the hydrazide 1) were identified using in silico screening combined with enzyme assays and were found to be selective for bacterial enzyme compared to human PK isoforms. Structure-activity relationship (SAR) studies were carried out on the replacement of the hydrazide linker with 3-atoms, 2-atoms and 0-atom linkers and led us to discover more potent compounds with enzyme inhibiting activities in the low nanomolar range and some were found to effectively inhibit bacteria growth in culture with minimum inhibitory concentrations (MIC) as low as 1 μg/mL.

  2. 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.

  3. A case of epididymitis associated with Panton-Valentine leukocidin Staphylococcus aureus.

    PubMed

    Raychaudhuri, Malini; Chew, Pei Ru

    2012-08-01

    A new pattern of disease caused by Panton-Valentine leukocidin (PVL)-positive strains of Staphylococcus aureus is emerging in the UK and worldwide. Community-associated methicillin-resistant S aureus (MRSA) is more likely to produce PVL, a pore-forming cytotoxin inducing leucocyte lysis, which often infects young healthy individuals. The worldwide emergence and continually increasing prevalence of community-acquired PVL-MRSA have recently attracted high-profile media attention and prompted concern regarding the transmissibility and virulence. This paper reports a case of genitourinary tract infection associated with PVL-positive community-associated MRSA in an immunocompetent young man.

  4. [Methicillin-resistant Staphylococcus aureus in pig breeders and cattle breeders].

    PubMed

    Vandenbroucke-Grauls, C M J E; Beaujean, D J M A

    2006-08-05

    It was recently observed that pig breeders in The Netherlands often carry methicillin-resistant Staphylococus aureus (MRSA). These MRSA strains are related to MRSA strains found in pigs. A case-control study showed that not only pig breeders but also cattle breeders are at risk of carrying MRSA. It is advised to keep pig breeders, if they are admitted to a hospital, in isolation until surveillance cultures are proven negative. This also applies to veterinarians and slaughterhouse personnel. For cattle breeders screening without isolation on admission to a hospital is sufficient.

  5. 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.

  6. Shedding of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus from adult and pediatric bathers in marine waters

    PubMed Central

    2011-01-01

    Background Staphylococcus aureus including methicillin resistant S. aureus, MRSA, are human colonizing bacteria that commonly cause opportunistic infections primarily involving the skin in otherwise healthy individuals. These infections have been linked to close contact and sharing of common facilities such as locker rooms, schools and prisons Waterborne exposure and transmission routes have not been traditionally associated with S. aureus infections. Coastal marine waters and beaches used for recreation are potential locations for the combination of high numbers of people with close contact and therefore could contribute to the exposure to and infection by these organisms. The primary aim of this study was to evaluate the amount and characteristics of the shedding of methicillin sensitive S. aureus, MSSA and MRSA by human bathers in marine waters. Results Nasal cultures were collected from bathers, and water samples were collected from two sets of pools designed to isolate and quantify MSSA and MRSA shed by adults and toddlers during exposure to marine water. A combination of selective growth media and biochemical and polymerase chain reaction analysis was used to identify and perform limited characterization of the S. aureus isolated from the water and the participants. Twelve of 15 MRSA isolates collected from the water had identical genetic characteristics as the organisms isolated from the participants exposed to that water while the remaining 3 MRSA were without matching nasal isolates from participants. The amount of S. aureus shed per person corresponded to 105 to 106 CFU per person per 15-minute bathing period, with 15 to 20% of this quantity testing positive for MRSA. Conclusions This is the first report of a comparison of human colonizing organisms with bacteria from human exposed marine water attempting to confirm that participants shed their own colonizing MSSA and MRSA into their bathing milieu. These findings clearly demonstrate that adults and

  7. 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 ...

  8. Evaluation of Multidrug Resistant Staphylococcus aureus and their Association with Biofilm Production in a Tertiary Care Hospital, Tripura, Northeast India

    PubMed Central

    Bir, Raunak; Majumdar, Tapan

    2015-01-01

    Background High morbidity and mortality rates are associated with Methicillin-resistant Staphylococcus aureus (MRSA) because of development of multidrug resistance. Staphylococcus aureus (S. aureus) has the ability to colonize and form biofilms on biomaterials which is causing resistance towards antimicrobials and thus making them difficult to eradicate from the infected hosts. Materials and Methods Culture isolation, identification was done following standard protocol and antibiogram of the isolates were done. The detection of MRSA, Macrolide-Lincosamide-Streptogramin B resistance (MLSB), vancomycin resistance phenotypes were done by using cefoxitin disc diffusion test, D zone test and vancomycin E test. Biofilm was detected by Congo red agar method. Results A total of 100 (31.7%) S. aureus strains were isolated from 315 clinical specimens. The prevalence of MRSA was 47% (47/100) with 85.1% were homogeneous MRSA and 14.9% were heterogeneous. Out of 47 MRSA strains, 63.8% were Hospital acquired-MRSA (HA-MRSA) infections whereas rests 36.2% were caused by Community acquired-MRSA (CA-MRSA) strains. Maximum number of MRSA isolates belonged to group A biotype (34%). A 14.9% isolates were of nontypeable group. Out of 100 S. aureus isolates, the prevalence of Vancomycin resistant S. aureus (VRSA) was found to be 3%. The MLSB phenotypes showed that the rates of inducible MLSB (iMLSB), constitutive MLSB (cMLSB) and Macrolide-Streptogramin B (MSB) in case of MRSA to be 19.1%, 31.9% and 12.8%. Prevalence of low-level (MUPL) and high-level mupirocin resistance (MUPH) among MRSA was 19.1% and 6.4%. Biofilm production was found in 55% strains of S. aureus. Out of 47 MRSA strains 76.6%were producing biofilm in comparison to 38.8% in methicillin-sensitive S. aureus (MSSA). Higher degree of antibiotic resistance in biofilm producers was seen especially in case of ciprofloxacin, co-trimoxazole, rifampicin, kanamycin, erythromycin and clindamycin whereas gentamycin, tetracycline and

  9. 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, NCK-10, did not induce development of resistance in planktonic cells in multiple passages and retained activity in varying environments of pH and salinity. At low concentrations the compound was able to depolarize and permeabilize the membranes of S. aureus persister cells rapidly. Treatment with the compound not only eradicated pre-formed MRSA biofilms, but also brought down viable counts in bacterial biofilms. In a murine model of MRSA skin infection, the compound was more effective than fusidic acid in bringing down the bacterial burden. Overall, this class of molecules bears potential as antibacterial agents against skin-infections. PMID:26669634

  10. Managing skin and soft-tissue infection and nosocomial pneumonia caused by MRSA: a 2014 follow-up survey.

    PubMed

    Dryden, Matthew; Andrasevic, Arjana Tambic; Bassetti, Matteo; Bouza, Emilio; Chastre, Jean; Baguneid, Mo; Esposito, Silvano; Giamarellou, Helen; Gyssens, Inge; Nathwani, Dilip; Unal, Serhat; Voss, Andreas; Wilcox, Mark

    2015-04-24

    As a follow-up to our 2009 survey, in order to explore opinion and practice on the epidemiology and management of meticillin-resistant Staphylococcus aureus (MRSA) in Europe, we conducted a second survey to elicit current opinions on this topic, particularly around antibiotic choice, dose, duration and route of administration. We also aimed to further understand how the management of MRSA has evolved in Europe during the past 5 years. Members of an expert panel of infectious diseases specialists convened in London (UK) in January 2014 to identify and discuss key issues in the management of MRSA. Following this meeting, a survey was developed comprising 36 questions covering a wide range of topics on MRSA complicated skin and soft-tissue infection and nosocomial pneumonia management. The survey instrument, a web-based questionnaire, was sent to the International Society of Chemotherapy for distribution to registered European infection societies and their members. This article reports the survey results from the European respondents. At the time of the original survey, the epidemiology of MRSA varied significantly across Europe and there were differing views on best practice. The current findings suggest that the epidemiology of healthcare-associated MRSA in Europe is, if anything, even more polarised, whilst community-acquired MRSA has become much more common. However, there now appears to be a much greater knowledge of current treatment/management options, and antimicrobial stewardship has moved forward considerably in the 5 years since the last survey.

  11. 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

  12. Evolution and diversity of community-associated methicillin-resistant Staphylococcus aureus in a geographical region

    PubMed Central

    2011-01-01

    Background Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) was first reported in remote regions of Western Australia and is now the predominant MRSA isolated in the state. The objective of this study is to determine the genetic relatedness of Western Australian CA-MRSA clones within different multilocus sequence type (MLST) clonal clusters providing an insight into the frequency of S. aureus SCCmec acquisition within a region. Results The CA-MRSA population in Western Australia is genetically diverse consisting of 83 unique pulsed-field gel electrophoresis strains from which 46 MLSTs have been characterised. Forty five of these sequence types are from 18 MLST clonal clusters and two singletons. While SCCmec IV and V are the predominant SCCmec elements, SCCmec VIII and several novel and composite SCCmec elements are present. The emergence of MRSA in diverse S. aureus clonal clusters suggests horizontal transmission of the SCCmec element has occurred on multiple occasions. Furthermore DNA microarray and spa typing suggests horizontal transfer of SCCmec elements has also occurred within the same CC. For many single and double locus variant CA-MRSA clones only a few isolates have been detected. Conclusions Although multiple CA-MRSA clones have evolved in the Western Australian community only three clones have successfully adapted to the Western Australian community environment. These data suggest the successful evolution of a CA-MRSA clone may not only depend on the mobility of the SCCmec element but also on other genetic determinants. PMID:21955438

  13. Methicillin-resistant Staphylococcus aureus ulcerative keratitis in a Thoroughbred racehorse

    PubMed Central

    KURODA, Taisuke; KINOSHITA, Yuta; NIWA, Hidekazu; MIZOBE, Fumiaki; UENO, Takanori; KUWANO, Atsutoshi; HATAZOE, Takashi; HOBO, Seiji

    2015-01-01

    ABSTRACT We report the first case of methicillin-resistant Staphylococcus aureus (MRSA) keratitis in a racehorse. A 5-year-old mare developed punctate keratitis after racing. The corneal ulcer continued to expand despite ophthalmic antimicrobial therapy. On day 6, a conjunctival graft surgery was performed. The mare was euthanized, following colitis and laminitis development on day 10. MRSA was isolated from the corneal swab taken at the time of euthanasia. Immunohistochemical analysis demonstrated gram-positive and anti-S. aureus monoclonal antibody-positive cocci infiltration of the corneal stroma; and a diagnosis of MRSA ulcerative keratitis was made. An ophthalmic antimicrobial against the isolated MRSA did not improve the ocular lesion. The MRSA strain was found to be staphylococcal cassette chromosome mec type II, a strain frequently isolated from humans in Japan. PMID:26435683

  14. Vancomycin-intermediate livestock-associated methicillin-resistant Staphylococcus aureus ST398/t9538 from swine in Brazil

    PubMed Central

    Moreno, Luisa Z; Dutra, Mauricio C; Moreno, Marina; Ferreira, Thais SP; da Silva, Givago FR; Matajira, Carlos EC; Silva, Ana Paula S; Moreno, Andrea M

    2016-01-01

    Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) has been mainly related with pig farming, in Europe and North America, with the ST398 as the most commonly identified type of LA-MRSA. Here we present the draft genome of the first vancomycin-intermediate MRSA ST398/t9538 isolated from a swine presenting exudative epidermitis in Brazil. PMID:27759766

  15. Roemerine Improves the Survival Rate of Septicemic BALB/c Mice by Increasing the Cell Membrane Permeability of Staphylococcus aureus

    PubMed Central

    He, Gonghao; Wang, Chengying; Ma, Chaoyu; Luo, Xiaoxing; Hou, Zheng; Xu, Guili

    2015-01-01

    Staphylococcus aureus is one of the most frequently occurring hospital- and community-associated pathogenic bacteria featuring high morbidity and mortality. The occurrence of methicillin-resistant S. aureus (MRSA) has increased persistently over the years. Therefore, developing novel anti-MRSA drugs to circumvent drug resistance of S. aureus is highly important. Roemerine, an aporphine alkaloid, has previously been reported to exhibit antibacterial activity. The present study aimed to investigate whether roemerine can maintain these activities against S.aureus in vivo and further explore the underlying mechanism. We found that roemerine is effective in vitro against four S. aureus strains as well as in vivo against MRSA insepticemic BALB/c mice. Furthermore, roemerine was found to increase cell membrane permeability in a concentration-dependent manner. These findings suggest that roemerine may be developed as a promising compound for treating S. aureus, especially methicillin-resistant strains of these bacteria. PMID:26606133

  16. Short communication: Prevalence of Staphylococcus aureus and methicillin-resistant S. aureus in bulk tank milk from dairy goat farms in Northern Italy.

    PubMed

    Cortimiglia, C; Bianchini, V; Franco, A; Caprioli, A; Battisti, A; Colombo, L; Stradiotto, K; Vezzoli, F; Luini, M

    2015-04-01

    Staphylococcus aureus is regarded as a leading cause of mastitis in goats. However, few data are available on the presence of methicillin-resistant S. aureus (MRSA) in this species. The aim of this study was to assess the prevalence of S. aureus and MRSA in bulk tank milk samples from dairy goat farms in Northern Italy. Eighty-five out of 197 samples (43.1%) tested positive for S. aureus with counts ranging from 10 to more than 1.5 × 10(4) cfu/mL. The MRSA was screened by both direct plating followed by a disk diffusion test to evaluate methicillin resistance and a selective enrichment method. Methicillin-resistance was confirmed by mecA-specific PCR. Methicillin-resistant S. aureus was identified in 4 samples (2.0%) and multilocus sequence typing (MLST) showed the presence of livestock-associated MRSA belonging to lineages ST398 (n = 3) and ST1 (n = 1). In one case we demonstrated that the same MRSA strain was able to persist over time on the farm, being isolated from both bulk tank milk and the udder of 3 goats 1 yr after the first isolation. The high prevalence of S. aureus-positive herds detected in this study and the presence of MRSA strains belonging to livestock-associated genotypes is of concern, and represents a novel finding in the Italian dairy goat production system. The application of stringent measures for the control of S. aureus mastitis at the farm level seems appropriate to reduce the economic losses, and to minimize the risk of foodborne illness and the transmission of MRSA to humans by occupational exposure.

  17. Asphodosides A-E, anti-MRSA metabolites from Asphodelus microcarpus.

    PubMed

    Ghoneim, Mohammed M; Elokely, Khaled M; El-Hela, Atef A; Mohammad, Abd-Elsalam I; Jacob, Melissa; Radwan, Mohamed M; Doerksen, Robert J; Cutler, Stephen J; Ross, Samir A

    2014-09-01

    Bioassay guided fractionation of the ethanolic extract of Asphodelus microcarpus Salzm. et Viv. (Xanthorrhoeaceae or Asphodelaceae) resulted in isolation of five compounds identified as asphodosides A-E (1-5). Compounds 2-4 showed activity against methicillin resistant Staphylococcus aureus (MRSA) with IC50 values of 1.62, 7.0 and 9.0μg/mL, respectively. They also exhibited activity against Staphylococcus aureus (non-MRSA) with IC50 values of 1.0, 3.4 and 2.2μg/mL, respectively. The structure elucidation of isolated metabolites was carried out using spectroscopic data (1D and 2D NMR), optical rotation and both experimental and calculated electronic circular dichroism (ECD).

  18. Functionalised nanoparticles complexed with antibiotic efficiently kill MRSA and other bacteria.

    PubMed

    Wang, Lei; Chen, Yung Pin; Miller, Kristen P; Cash, Brandon M; Jones, Shonda; Glenn, Steven; Benicewicz, Brian C; Decho, Alan W

    2014-10-18

    Antibiotic-resistant bacterial infections are a vexing global health problem and have rendered ineffective many previously-used antibiotics. Here we demonstrate that antibiotic-linkage to surface-functionalized silica nanoparticles (sNP) significantly enhances their effectiveness against Escherichia coli, and Staphylococcus aureus, and even methicillin-resistant S. aureus (MRSA) strains that are resistant to most antibiotics. The commonly-used antibiotic penicillin-G (PenG) was complexed to dye-labeled sNPs (15 nm diameter) containing carboxyl groups located as either surface-functional groups, or on polymer-chains extending from surfaces. Both sNPs configurations efficiently killed bacteria, including MRSA strains. This suggests that activities of currently-ineffective antibiotics can be restored by nanoparticle-complexation and used to avert certain forms of antibiotic-resistance.

  19. Transmission Dynamics of Methicillin-Resistant Staphylococcus aureus in Pigs

    PubMed Central

    Crombé, Florence; Argudín, M. Angeles; Vanderhaeghen, Wannes; Hermans, Katleen; Haesebrouck, Freddy; Butaye, Patrick

    2013-01-01

    From the mid-2000s on, numerous studies have shown that methicillin-resistant Staphylococcus aureus (MRSA), renowned as human pathogen, has a reservoir in pigs and other livestock. In Europe and North America, clonal complex (CC) 398 appears to be the predominant lineage involved. Especially worrisome is its capacity to contaminate humans in close contact with affected animals. Indeed, the typical multi-resistant phenotype of MRSA CC398 and its observed ability of easily acquiring genetic material suggests that MRSA CC398 strains with an increased virulence potential may emerge, for which few therapeutic options would remain. This questions the need to implement interventions to control the presence and spread of MRSA CC398 among pigs. MRSA CC398 shows a high but not fully understood transmission potential in the pig population and is able to persist within that population. Although direct contact is probably the main route for MRSA transmission between pigs, also environmental contamination, the presence of other livestock, the herd size, and farm management are factors that may be involved in the dissemination of MRSA CC398. The current review aims at summarizing the research that has so far been done on the transmission dynamics and risk factors for introduction and persistence of MRSA CC398 in farms. PMID:23518663

  20. Community-Associated Methicillin-Resistant Staphylococcus aureus: Epidemiology and Clinical Consequences of an Emerging Epidemic

    PubMed Central

    David, Michael Z.; Daum, Robert S.

    2010-01-01

    Summary: Staphylococcus aureus is an important cause of skin and soft-tissue infections (SSTIs), endovascular infections, pneumonia, septic arthritis, endocarditis, osteomyelitis, foreign-body infections, and sepsis. Methicillin-resistant S. aureus (MRSA) isolates were once confined largely to hospitals, other health care environments, and patients frequenting these facilities. Since the mid-1990s, however, there has been an explosion in the number of MRSA infections reported in populations lacking risk factors for exposure to the health care system. This increase in the incidence of MRSA infection has been associated with the recognition of new MRSA clones known as community-associated MRSA (CA-MRSA). CA-MRSA strains differ from the older, health care-associated MRSA strains; they infect a different group of patients, they cause different clinical syndromes, they differ in antimicrobial susceptibility patterns, they spread rapidly among healthy people in the community, and they frequently cause infections in health care environments as well. This review details what is known about the epidemiology of CA-MRSA strains and the clinical spectrum of infectious syndromes associated with them that ranges from a commensal state to severe, overwhelming infection. It also addresses the therapy of these infections and strategies for their prevention. PMID:20610826

  1. Healthcare-Associated Methicillin-Resistant Staphylococcus aureus

    PubMed Central

    Kumari, Jyoti; Shenoy, Shalini M.; Baliga, Shrikala; Chakrapani, M.; Bhat, Gopalkrishna K.

    2016-01-01

    Objectives: Healthcare-associated methicillin-resistant Staphylococcus aureus (MRSA) is a common pathogen worldwide and its multidrug resistance is a major concern. This study aimed to determine the clinical characteristics and antibiotic susceptibility profile of healthcare-associated MRSA with emphasis on resistance to macrolide-lincosamide-streptogramin B (MLSB) phenotypes and vancomycin. Methods: This cross-sectional study was carried out between February 2014 and February 2015 across four tertiary care hospitals in Mangalore, South India. Healthcare-associated infections among 291 inpatients at these hospitals were identified according to the Centers for Disease Control and Prevention guidelines. Clinical specimens were collected based on infection type. S. aureus and MRSA isolates were identified and antibiotic susceptibility tests performed using the Kirby-Bauer disk diffusion method. The minimum inhibitory concentration of vancomycin was determined using the Agar dilution method and inducible clindamycin resistance was detected with a double-disk diffusion test (D-test). Results: Out of 291 healthcare-associated S. aureus cases, 88 were MRSA (30.2%). Of these, 54.6% were skin and soft tissue infections. All of the isolates were susceptible to teicoplanin and linezolid. Four MRSA isolates exhibited intermediate resistance to vancomycin (4.6%). Of the MRSA strains, 10 (11.4%) were constitutive MLSB phenotypes, 31 (35.2%) were inducible MLSB phenotypes and 14 (15.9%) were macrolide-streptogramin B phenotypes. Conclusion: Healthcare-associated MRSA multidrug resistance was alarmingly high. In routine antibiotic susceptibility testing, a D-test should always be performed if an isolate is resistant to erythromycin but susceptible to clindamycin. Determination of the minimum inhibitory concentration of vancomycin is necessary when treating patients with MRSA infections. PMID:27226908

  2. Methicillin-resistant Staphylococcus aureus: a new zoonotic agent?

    PubMed

    Springer, Burkhard; Orendi, Ulrike; Much, Peter; Höger, Gerda; Ruppitsch, Werner; Krziwanek, Karina; Metz-Gercek, Sigrid; Mittermayer, Helmut

    2009-01-01

    Staphylococcus aureus is a major cause of infection in hospitals and the community. One third of the general population is colonized by the bacterium, constituting a risk factor for acquisition of infection with this pathogen. Worldwide, the increasing antibiotic resistance of S. aureus complicates treatment of infection and control measures. Soon after the introduction of methicillin, the first isolates resistant to this antibiotic were reported and named methicillin-resistant S. aureus (MRSA). During the past decade a major change in MRSA epidemiology has been observed: whereas in the past MRSA was almost exclusively regarded a hospital pathogen, the advent of community-acquired MRSA has led to infections in people without hospital-related risk factors. Recent evidence has also identified a link between colonization of livestock and MRSA carriage and infections in people who work with animals. Screening of pigs and pig farmers in the Netherlands revealed high prevalence of MRSA sequence type (ST) 398 and it has become clear that the emergence of ST398 is not just a Dutch problem, as reports on livestock colonization and human infections are appearing worldwide. In Austria, the ST398 lineage has been detected in dust samples from pig breeding facilities and in food samples. Since the first Austrian detection of this emerging lineage in 2006, 21 human isolates, partially associated with infections, have been observed. MRSA has to be regarded as a new emerging zoonotic agent and livestock may constitute a growing reservoir of the ST398 lineage. More information is needed so that control measures to reduce the impact of the emerging MRSA ST398 lineage on public health can be developed and implemented.

  3. Methicillin resistance in Staphylococcus aureus strains isolated from food and wild animal carcasses in Italy.

    PubMed

    Traversa, A; Gariano, G R; Gallina, S; Bianchi, D M; Orusa, R; Domenis, L; Cavallerio, P; Fossati, L; Serra, R; Decastelli, L

    2015-12-01

    Following the detection of methicillin-resistant Staphylococcus aureus (MRSA) ST398 in food-producing animals, both livestock and wildlife, and derived products, are considered potential sources of MRSA in humans. There is a paucity of data on MRSA in foods in Italy, and the data regarding wild animals are particularly scarce. A total of 2162 food samples collected during official monitoring activities in 2008 were analyzed for the detection of S. aureus. Also, samples from 1365 wild animals collected by the National Reference Center for Wild Animal Diseases in 2003-2009 were subjected to anatomopathological examination. S. aureus isolates were processed for phenotypic and molecular methicillin resistance determinations. S. aureus was found in 2.0% of wild animal carcasses and in 3.2% of wild boar lymph nodes: none showed methicillin resistance. The prevalence of S. aureus in food was 17.1%. Two MRSA strains, both from bulk tank milk (prevalence 0.77%) were isolated: the strains were resistant to tetracycline, had spa-type t899, and were negative for the Panton-Valentine leukocidin gene. The low prevalence of MRSA suggests that the risk of transmission to humans via food is limited. However, attention should be paid to the cattle food chain, which may be a potential route of transmission of LA-MRSA.

  4. Prevalence and Characterization of Staphylococcus aureus, Including Methicillin-Resistant Staphylococcus aureus, Isolated from Bulk Tank Milk from Minnesota Dairy Farms

    PubMed Central

    Haran, K. P.; Godden, S. M.; Boxrud, D.; Jawahir, S.; Bender, J. B.

    2012-01-01

    Staphylococcus aureus is a common causative agent of bovine mastitis in dairy herds. The emergence of methicillin-resistant Staphylococcus aureus (MRSA) in hospitals as well as the community is a significant and costly public health concern. S. aureus-related bovine mastitis is a common reason for therapeutic and/or prophylactic use of antibiotics on dairy farms. In this study, herd prevalence of S. aureus, including MRSA, was estimated from bulk tank milk (BTM) from Minnesota farms. A total of 150 pooled BTM samples from 50 farms, collected over 3 seasons (spring, summer, and fall of 2009), were assessed. Herd prevalence of methicillin-susceptible S. aureus (MSSA) was 84%, while MRSA herd prevalence was 4%. A total of 93 MSSA isolates and 2 MRSA isolates were recovered from 150 BTM samples. Antibiotic susceptibility testing of S. aureus isolates showed pansusceptibility in 54 isolates, resistance to a single antibiotic class in 21 isolates, resistance to two antibiotic classes in 13 isolates, and resistance to ≥3 antibiotics classes and thus multidrug resistance in 5 isolates. The two MRSA isolates displayed resistance to β-lactams, cephalosporins, and lincosamides and were multiresistant. Staphylococcal protein A gene (spa) typing identified spa types t529 and t034 most frequently among methicillin-susceptible isolates, while t121 was observed in MRSA isolates. Seven isolates, including the two MRSA isolates, produced staphylococcal enterotoxins B, C, D, and E on overnight culture. MRSA isolates were further genotyped using multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). Of the 2 MRSA isolates, one had a composite genotype profile of MLST ST 5-PFGE USA100-unknown spa type, which has been reported among hospital-associated MRSA isolates, while the second isolate carried the MLST ST 8-PFGE USA300-spa type t121 genotype, commonly identified among community-associated MRSA isolates. These results suggest that MRSA genotypes

  5. Use of the cobas 4800 system for the rapid detection of toxigenic Clostridium difficile and methicillin-resistant Staphylococcus aureus.

    PubMed

    Moure, Raquel; Cañizares, Ángeles; Muíño, María; Lobato, Margarita; Fernández, Ana; Rodríguez, María; Gude, Maria José; Tomás, Maria; Bou, Germán

    2016-01-01

    The new cobas® Cdiff and cobas® MRSA/SA tests were compared with conventional methods for the rapid detection of toxigenic Clostridium difficile and methicillin-resistant Staphylococcus aureus. The final concordance between cobas Cdiff Test and GDH/toxin gene screening was 97.62% and between cobas MRSA/SA Test and chromogenic culture, 91.30%, respectively.

  6. Novel hamamelitannin analogues for the treatment of biofilm related MRSA infections-A scaffold hopping approach.

    PubMed

    Vermote, Arno; Brackman, Gilles; Risseeuw, Martijn D P; Coenye, Tom; Van Calenbergh, Serge

    2017-02-15

    Antimicrobial research is increasingly being focused on the problem of resistance and biofilm formation. Hamamelitannin (HAM) was recently identified as an antimicrobial potentiator for conventional antibiotics towards Staphylococcus aureus. This paper describes the synthesis and biological evaluation of novel hamamelitannin analogues with alternative central scaffolds. Via a ligand-based approach, several interesting compounds with improved synthetic accessibility were identified as potentiators for vancomycin in the treatment of MRSA infections.

  7. MRSA from Santa Catarina State, Southern Brazil: intriguing epidemiological differences compared to other Brazilian regions.

    PubMed

    Silveira, Alessandro C O; Cunha, Gabriela R; Caierão, Juliana; Cordova, Caio M de; d'Azevedo, Pedro A

    2015-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most frequently isolated agents in both nosocomial and community settings. It is a constant challenge for antibacterial therapy. Therefore, it becomes essential to understand the epidemiology of MRSA isolates in the institution and/or region to guide empirical therapy. The objective of this study was to evaluate the epidemiological characteristics of MRSA isolates in the state of Santa Catarina, Brazil, and determine if there is a clonal spread. We evaluated 124 clinical isolates of MRSA obtained from various anatomical sites from patients in the state of Santa Catarina in Southern Brazil. The antimicrobial susceptibility profile was evaluated by disk diffusion and minimum inhibitory concentration (MIC) was determined by Etest and broth macrodilution. SCCmec types were determined by multiplex PCR and the clonal relationship among isolates was assessed by pulsed field gel electrophoresis. Antimicrobials that have demonstrated lower rates of resistance were tetracycline (20.2%), sulfamethoxazole-trimethoprim (20.2%) and chloramphenicol (12.9%). We did not detect any resistance to glycopeptides, daptomycin, linezolid, and tigecycline. SCCmec type III was predominant (54%), followed by type II (21.8%), consistent with other Brazilian studies. Twenty-six clones were observed grouping 72 (58%) isolates and no clonal relationship was observed between our isolates and the major epidemic clones circulating in Brazil. An intriguing distinct MRSA epidemiology was observed in Santa Catarina, compared to other Brazilian regions.

  8. Prevalence and Characterization of Staphylococcus aureus in Growing Pigs in the USA

    PubMed Central

    Sun, Jisun; Yang, My; Sreevatsan, Srinand; Davies, Peter R.

    2015-01-01

    A decade of research of methicillin-resistant S. aureus (MRSA) in pigs shows that the prevalence and predominant genotypes (i.e., ST398, ST9, ST5) of MRSA vary widely geographically, yet knowledge of the epidemiology of S. aureus generally in swine remains rudimentary. To characterize S. aureus, including MRSA, in the US swine industry, we sampled 38 swine herds in 11 states in major swine producing regions. The herds sampled included pigs sourced from 9 different breeding stock companies, and the sample was likely biased towards larger herds that use regular veterinary services. Twenty nasal swabs were collected from 36 groups of growing pigs by 36 swine veterinarians, 2 more herds were sampled opportunistically, and a historically MRSA-positive herd was included as a positive control. S. aureus was detected on 37 of the 38 herds, and in 77% of pigs sampled. Other than the positive control herd, no MRSA were detected in the study sample, yielding a 95% upper confidence limit of 9.3% for MRSA herd prevalence. All but two (ST1-t127; ST2007-t8314) of 1200 isolates belonged to three MLST lineages (ST9, ST398, and ST5) that have been prominent in studies of MRSA in pigs globally. A total of 35 spa types were detected, with the most prevalent being t337 (ST9), t034 (ST398), and t002 (ST5). A purposively diverse subset of 128 isolates was uniformly negative on PCR testing for major enterotoxin genes. The findings support previous studies suggesting a relatively low herd prevalence of MRSA in the US swine industry, but confirm that methicillin susceptible variants of the most common MRSA genotypes found in swine globally are endemic in the US. The absence of enterotoxin genes suggests that the source of toxigenic S. aureus capable of causing foodborne enterotoxicosis from pork products is most likely post-harvest contamination. PMID:26599635

  9. Use of natural antimicrobials from a food safety perspective for control of Staphylococcus aureus.

    PubMed

    Li, Min; Muthaiyan, Arunachalam; O'Bryan, Corliss A; Gustafson, John E; Li, Y; Crandall, Philip G; Ricke, Steven C

    2011-08-01

    Staphylococcus aureus (S. aureus) is an important foodborne and environmental pathogen that can produce toxins in foods and cause infections in soft tissues. S. aureus that have developed resistance to the conventional antimicrobials are commonly called Methicillin-Resistant Staphylococcus aureus (MRSA) and Vancomycin-Resistant S. aureus (VRSA). Their prevalence is believed to be due to the widespread use of antibiotics. Therefore, natural antimicrobials are in urgent demand as alternatives to conventional antibiotics to treat S. aureus infections. In this review, natural antimicrobials from plant, animal and microbiological origins are discussed, including their mode of action and mechanisms of bacterial resistance, major components, chemical structure, effectiveness, synergistic effects and future prospects.

  10. Prevalence of methicillin-resistant Staphylococcus aureus colonization and infection in hospitalized palliative care patients with cancer.

    PubMed

    Ghanem, Hafez M; Abou-Alia, Ahmad M; Alsirafy, Samy A

    2013-06-01

    Little is known about the pattern of methicillin-resistant Staphylococcus aureus (MRSA) colonization and infection in hospitalized palliative care (PC) patients. We reviewed 854 admissions for 289 patients with advanced cancer managed by a PC service in a tertiary care hospital. The MRSA screening was performed at least once in 228 (79%) patients, and 21 (9%) of them were MRSA positive. Other cultures were done in 251 (86.8%) patients, and 8 (3%) patients were MRSA positive. The total number of MRSA-positive admissions was 28 (3%), with a median admission duration of 8 days. A substantial proportion of hospitalized PC patients with cancer are MRSA positive. Research is required to study the impact of infection control measures on the quality of PC delivered to MRSA-positive terminally ill patients in hospitals.

  11. Genomic analysis of ST88 community-acquired methicillin resistant Staphylococcus aureus in Ghana

    PubMed Central

    Buultjens, Andrew H.; Giulieri, Stefano; Owusu-Mireku, Evelyn; Aboagye, Samuel Y.; Baines, Sarah L.; Gonçalves da Silva, Anders; Howden, Benjamin P.; Pluschke, Gerd; Yeboah-Manu, Dorothy

    2017-01-01

    Background The emergence and evolution of community-acquired methicillin resistant Staphylococcus aureus (CA-MRSA) strains in Africa is poorly understood. However, one particular MRSA lineage called ST88, appears to be rapidly establishing itself as an “African” CA-MRSA clone. In this study, we employed whole genome sequencing to provide more information on the genetic background of ST88 CA-MRSA isolates from Ghana and to describe in detail ST88 CA-MRSA isolates in comparison with other MRSA lineages worldwide. Methods We first established a complete ST88 reference genome (AUS0325) using PacBio SMRT sequencing. We then used comparative genomics to assess relatedness among 17 ST88 CA-MRSA isolates recovered from patients attending Buruli ulcer treatment centres in Ghana, three non-African ST88s and 15 other MRSA lineages. Results We show that Ghanaian ST88 forms a discrete MRSA lineage (harbouring SCCmec-IV [2B]). Gene content analysis identified five distinct genomic regions enriched among ST88 isolates compared with the other S. aureus lineages. The Ghanaian ST88 isolates had only 658 core genome SNPs and there was no correlation between phylogeny and geography, suggesting the recent spread of this clone. The lineage was also resistant to multiple classes of antibiotics including β-lactams, tetracycline and chloramphenicol. Discussion This study reveals that S. aureus ST88-IV is a recently emerging and rapidly spreading CA-MRSA clone in Ghana. The study highlights the capacity of small snapshot genomic studies to provide actionable public health information in resource limited settings. To our knowledge this is the first genomic assessment of the ST88 CA-MRSA clone. PMID:28265515

  12. Molecular characterization and clonal diversity of meticillin-resistant Staphylococcus aureus isolated from the community in Spain: emergence of clone sequence type 72.

    PubMed

    Potel, C; Rey, S; Otero, S; Rubio, J; Álvarez, M

    2016-08-01

    Sequence type 72 meticillin-resistant Staphylococcus aureus (ST72 MRSA) was recently detected in our hospital. Although in Europe this clone is rarely isolated, it is the leading cause of community-associated MRSA infections in Korea, spreading also into hospitals, where it has also emerged as the main MRSA clone recovered from raw meat. We studied MRSA isolated from outpatients in Spain during a nine-year period. More than 70% of the isolates belonged to predominant clones found in hospitals. There was a significant increase in the ST72 prevalence. It appears that boundaries of dominance among MRSA clones have become blurred, demanding continuous surveillance.

  13. Methicillin-Resistant Staphylococcus aureus in the Community in Luanda, Angola: Blurred Boundaries with the Hospital Setting.

    PubMed

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

    2016-01-01

    Although the nosocomial prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in Angola is over 60% and one of the highest in Africa, the extent of MRSA in the community is unknown. To fill this gap, we conducted a hospital-based study in which 158 children attending the emergency ward and ambulatory services of a pediatric hospital in Luanda, the capital of Angola, were screened for S. aureus nasal colonization. Overall, 70 (44.3%) individuals were colonized with S. aureus, of which 20 (28.6%) carried MRSA, resulting in a prevalence of 12.7% (20/158) of MRSA in the population screened. Molecular characterization by pulsed-field gel electrophoresis (PFGE), spa typing, multilocus sequence typing, and SCCmec typing distributed the isolates into two major MRSA clones and one dominant methicillin-susceptible S. aureus (MSSA) lineage, corresponding to the main clones circulating in hospitals in Luanda. The MRSA isolates mainly belonged to clones A (PFGE type A, spa type t105, ST5-IVa-65%) and B (PFGE B, t3869, ST88-IVa-30%), while MSSA isolates mainly belonged to clone L (PFGE type L, t861, ST508-42%). S. aureus isolates showed resistance to penicillin (96%), rifampin (87%), and trimethoprim-sulfamethoxazole (21%). In conclusion, the prevalence of MRSA among children in the community in Luanda is high and seems to originate from hospitals, warranting continuous monitoring and implementation of additional infection control measures.

  14. Higher prevalence of meticillin-resistant Staphylococcus aureus among dental students.

    PubMed

    Martínez-Ruíz, F J; Carrillo-Espíndola, T Y; Bustos-Martínez, J; Hamdan-Partida, A; Sánchez-Pérez, L; Acosta-Gío, A E

    2014-03-01

    In order to test the hypothesis that more dental students are meticillin-resistant Staphylococcus aureus (MRSA) carriers than non-dental students, 100 dental students with five to six years of exposure to patients and 81 non-dental students were tested for nasal and pharyngeal MRSA carriage by polymerase chain reaction. All 181 students were clinically healthy and none had taken antibiotics. Significantly more dental students (20/100) carried MRSA than non-dental students (5/81) (odds ratio: 4.04; 95% confidence interval: 1.6-12.6; P = 0.0033). Also, more dental students' mobile phones (8/100) carried MRSA. All MRSA isolates were distinguished by pulsed-field gel electrophoresis from epidemiologically significant strains. The results suggest that dental students are occupationally exposed to MRSA.

  15. Staphylococcus aureus ST398 from slaughter pigs in northeast China.

    PubMed

    Yan, Xiaomei; Yu, Xiaojie; Tao, Xiaoxia; Zhang, Jianfeng; Zhang, Binghua; Dong, Rui; Xue, Chengyu; Grundmann, Hajo; Zhang, Jianzhong

    2014-05-01

    To describe the prevalence and population structure of Staphylococcus aureus bacteria that colonize pigs at slaughterhouses in northeastern China, nose swabs were collected from pigs in two slaughterhouses in Harbin, Heilongjiang Province, China in 2009. S. aureus isolates were characterized by multilocus sequence typing (MLST), spa typing, SCCmec typing, antimicrobial susceptibility testing and pvl gene detection. A total of 200 S. aureus isolates were collected from 590 pigs (33.9%, 200/590), of which 162 (81%, 162/200) were methicillin-susceptible S. aureus (MSSA) and 38 (19%, 38/200) were methicillin-resistant S. aureus (MRSA). Ninety-nine of the MSSA isolates (99/162, 61.1%) were ST398, which represented the dominant sequence type overall. Eighty-seven isolates were ST9 (87/200, 43.5%), and all MRSA belonged to that sequence type which consisted of the spa types t899 and t2922. Among the MSSA strains, t034, t899 and t4358 were the most dominant spa types (139/162, 85.8%). All MRSA isolates harbored SCCmec type IVb. The pvl gene was only detected in 3 ST7/t2119 MSSA isolates. All MRSA but more importantly also 82.7% (134/162) of the MSSA isolates were resistant to six or more antibiotics. Moreover, a novel resistance determinant-lsa(E) was identified among 22% (44/200) of all isolates. In conclusion, pigs in northeast China are frequently colonized with ST398 MSSA. MRSA with this sequence type, typically associated with pigs in Europe, was not found. High levels of multiple antibiotic resistance among MRSA isolates as well as MSSA isolates are a public health concern.

  16. Characterisation of Staphylococcus aureus isolates from bloodstream infections, Democratic Republic of the Congo.

    PubMed

    Vandendriessche, S; De Boeck, H; Deplano, A; Phoba, M-F; Lunguya, O; Falay, D; Dauly, N; Verhaegen, J; Denis, O; Jacobs, J

    2017-01-23

    Staphylococcus aureus is known worldwide as an invasive pathogen, but information on S. aureus from bloodstream infections in Central Africa remains scarce. A collection of S. aureus blood culture isolates recovered from hospitals in four provinces in the Democratic Republic of the Congo (2009-2013) was assessed. A total of 27/108 isolates were methicillin-resistant S. aureus (MRSA), of which >70% were co-resistant to aminoglycosides, tetracyclines, macrolides and lincosamides. For MRSA and methicillin-susceptible S. aureus (MSSA) isolates, resistance to chloramphenicol and trimethoprim-sulphamethoxazole (TMP-SMX) was <10%. However, 66.7% (72/108) of all isolates harboured the trimethoprim resistance gene dfrG. More than three-quarters (84/108, 77.8%) of isolates belonged to CC5, CC8, CC121 or CC152. Genetic diversity was higher among MSSA (31 spa types) compared to MRSA (four spa types). Most MRSA (23/27, 85.2%) belonged to CC8-spa t1476-SCCmec V and 17/23 (73.9%) MRSA ST8 were oxacillin susceptible but cefoxitin resistant. Among MRSA and MSSA combined, 49.1% (53/108) and 19.4% (21/108) contained the genes encoding for Panton-Valentine leucocidin (lukS-lukF PV, PVL) and toxic shock syndrome toxin-1 (tst, TSST-1), respectively. PVL was mainly detected among MSSA (51/53 isolates harbouring PVL were MSSA, 96.2%) and associated with CC121, CC152, CC1 and CC5. TSST-1 was associated with CC8-spa t1476-SCCmec V. The immune evasion cluster (IEC) genes scn, sak and chp were detected in 81.5% of isolates (88/108, equally represented among MSSA and MRSA). The present study confirms the occurrence of MRSA with high levels of multidrug co-resistance and PVL-positive MSSA among invasive S. aureus isolates in Central Africa.

  17. 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 Central

    Morelli, John J.; Hogan, Patrick G.; Sullivan, Melanie L.; Muenks, Carol E.; Wang, Jeffrey W.; Thompson, Ryley M.

    2015-01-01

    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. PMID:26248385

  18. Nasal carriage of methicillin resistant Staphylococcus aureus and their antibiotic susceptibility patterns in children attending day-care centers.

    PubMed

    Sedighi, Iraj; Moez, Hoda Jaefari; Alikhani, Mohammad Yousef

    2011-09-01

    Nasal colonization with community acquired methicillin resistant Staphylococcus aureus (CA-MRSA) is being increasingly reported, especially in places where people are in close contact and in reduced hygiene, such as day-care centers. In this study we investigated the frequency of MRSA colonization and their antibiotic susceptibility patterns in 1-6 years old children of day-care centers in Hamadan, West of Iran.Five hundred nasal swabs were collected from children of 27 day-care centers that had no risk factors for colonization by S. aureus. The specimens were cultured for isolation of S. aureus by standard methods. Antimicrobial susceptibility testing was performed according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. For evaluation of the frequency of erythromycin induced clindamycin resistance, disk approximation test (D-test) was applied.Totally, 148 (29.6%) children were colonized by S. aureus. Out of 260 male, 94 (36.2%) and of 240 female, 54 (22.5%) cases were nasal carriers of S. aureus (P value = 0.001). Six (4.1%) of the 148 S. aureus isolated from children were MRSA strains. None of MRSA and methicillin susceptible S. aureus (MSSA) was resistant to vancomycin and clindamycin. Three of the 6 strains of MRSA and 7 (4.9%) of the 142 MSSA strains were resistant to erythromycin, and D-test was positive in all of them.We conclude that the rate of colonization by S. aureus is high in children attending day-care centers but colonization with MRSA is not common in our areas. Clindamycin or trimethoprim-sulfamethoxazol could be used in mild to moderataly severe diseases caused by CA-MRSA. However, if the CA-MRSA isolates are erythromycin resistant, D-test should be carried out for detection of inducible clindamycin resistance.

  19. Use of Corynebacterium pseudodiphtheriticum for elimination of Staphylococcus aureus from the nasal cavity in volunteers exposed to abnormal microclimate and altered gaseous environment.

    PubMed

    Kiryukhina, N V; Melnikov, V G; Suvorov, A V; Morozova, Yu A; Ilyin, V K

    2013-12-01

    Effectiveness of saline suspension of Corynebacterium pseudodiphtheriticum containing spray was assessed in a 30-days chamber experiment modeling the effects of hyperthermia and polluted air on humans. Spray was targeted at eliminating Staphylococcus aureus from the nasal cavity of human subjects. Three of four volunteers became S. aureus carriers in the course of the experiment, and one was a chronic carrier of methicillin-resistant S. aureus (MRSA). Spray application eradicated S. aureus in three subjects and reduced its presence in the MRSA carrier. Results of the study suggest that C. pseudodiphtheriticum can be used for control of S. aureus in the nasal environment. However, further investigations are required.

  20. Survey of policy for MRSA screening in English cataract surgical units and changes to practice after updated National guidelines

    PubMed Central

    2013-01-01

    Background National guidelines on MRSA (methicillin-resistant Staphylococcus aureus) screening policy in England have changed on a number of occasions, but there is limited data on its influence at a local level. The aim of this study was to determine if changes in National policy influenced preoperative screening of cataract patients for MRSA. Methods A structured telephone survey was conducted on all 133 ophthalmology units in England in 2004 and again in 2007 for the initial responders, after a change in national policy. Results A total of 74 units (56%) responded in 2004 and 71 units (96% of initial respondents) in 2007. In 2004, 57% of units screened for MRSA. They screened groups at high risk of carriage, including patients with previous MRSA (93%) and patients from Nursing homes (21%). Swab sites included the nose (100%), eyes (31%) and perineum (62%). In 2007, there was no significant change in the number of units that screened for MRSA (57% vs 66%; p = 0.118; McNemar test). However, more units screened for MRSA in patients from nursing/residential homes (21% vs 51%; p = 0.004, McNemar test), and in patients who had recent admission to hospital (12% vs 36%; p = 0.003). In the second survey, 3 units (6%) now screened patients who were close relatives of MRSA carriers. Conclusion This survey has highlighted inconsistences in MRSA screening practice of day-case cataract surgery patients across England after 2 major national policy changes. A change in DoH policy only led to more units screening patients for MRSA from high risk groups. PMID:24341357

  1. New epidemiology of Staphylococcus aureus infection in Africa.

    PubMed

    Schaumburg, F; Alabi, A S; Peters, G; Becker, K

    2014-07-01

    Research on African Staphylococcus aureus has been largely neglected in the past, despite the cultural and geographical diversity in Africa, which has a significant impact on the epidemiology of this pathogen. The polarity between developed urban societies and remote rural populations (e.g. Pygmies), combined with close contact with animals (e.g. livestock and domestic animals, and wildlife), makes the epidemiology of S. aureus on the African continent unique and fascinating. Here, we try to draw an epidemiological picture of S. aureus colonization and infection in Africa, and focus on the wide spread of Panton-Valentine leukocidin-positive isolates, the emergence of the hypervirulent methicillin-resistant S. aureus (MRSA) clone USA300, and the dissemination of the typical African clone MRSA sequence type 88.

  2. Environmental Staphylococcus aureus contamination in a Tunisian hospital.

    PubMed

    Gharsa, Haythem; Dziri, Raoudha; Klibi, Naouel; Chairat, Sarra; Lozano, Carmen; Torres, Carmen; Bellaaj, Ridha; Slama, Karim Ben

    2016-12-01

    One hundred hospital environment samples were obtained in 2012 in a Tunisian hospital and tested for Staphylococcus aureus recovery. Antimicrobial resistance profile and virulence gene content were determined. Multilocus-sequence-typing (MLST), spa-typing, agr-typing and SmaI-pulsed-field gel electrophoresis (PFGE) were performed. Two methicillin-resistant S. aureus (MRSA) isolates typed as: ST247-t052-SCCmecI-agrI were recovered from the intensive care unit (ICU). Ten samples contained methicillin-susceptible S. aureus (MSSA) and these samples were collected in different services, highlighting the presence of the tst gene encoding the toxic shock syndrome toxin as well as the lukED, hla, hlb, hld and hlgv virulence genes in some of the isolates. In conclusion, we have shown that the hospital environment could be a reservoir contributing to dissemination of virulent S. aureus and MRSA.

  3. Community-acquired methicillin-resistant Staphylococcus aureus: an emerging cause of acute bacterial parotitis.

    PubMed

    Nicolasora, Nelson P; Zacharek, Mark A; Malani, Anurag N

    2009-02-01

    Staphylococcus aureus has long been recognized as a cause of acute bacterial parotitis. A case of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) parotitis is presented, highlighting the emergence of this increasingly important pathogen to cause a wide variety of infections. Also reviewed are the salient clinical and microbiologic features of this novel infection.

  4. Persistent nasal methicillin-resistant staphylococcus aureus carriage in hemodialysis outpatients: a predictor of worse outcome

    PubMed Central

    2013-01-01

    Background Nasal colonization with methicillin-resistant Staphylococcus aureus (MRSA) is a well defined risk factor for subsequent bacteremia and death in various groups of patients, but its impact on outcome in patients receiving long-term hemodialysis (HD) is under debate. Methods This prospective interventional cohort study (performed 2004 to 2010) enrolled 289 HD outpatients of an urban dialysis-unit. Nasal swab cultures for MRSA were performed in all patients upon first admission, at transfer from another dialysis facility or readmission after hospitalisation. Nasal MRSA carriers were treated in a separate ward and received mupirocin nasal ointment. Concomitant extra-nasal MRSA colonization was treated with 0.2% chlorhexidine mouth rinse (throat) or octenidine dihydrochloride containing antiseptic soaps and 2% chlorhexidine body washes (skin). Clinical data and outcome of carriers and noncarriers were systematically analyzed. Results The screening approach identified 34 nasal MRSA carriers (11.7%). Extra-nasal MRSA colonization was observed in 11/34 (32%) nasal MRSA carriers. History of malignancy and an increased Charlson Comorbidity Index were significant predictors for nasal MRSA carriers, whereas traditional risk factors for MRSA colonization or markers of inflammation or malnutrition were not able to discriminate. Kaplan-Meier analysis demonstrated significant survival differences between MRSA carriers and noncarriers. Mupirocin ointment persistently eliminated nasal MRSA colonization in 26/34 (73.5%) patients. Persistent nasal MRSA carriers with failure of this eradication approach had an extremely poor prognosis with an all-cause mortality rate >85%. Conclusions Nasal MRSA carriage with failure of mupirocin decolonization was associated with increased mortality despite a lack of overt clinical signs of infection. Further studies are needed to demonstrate whether nasal MRSA colonization represents a novel predictor of worse outcome or just another

  5. MRSA

    MedlinePlus

    ... come into contact with bare skin. Cover shared sports equipment with a barrier (clothing or a ... different medicines and approaches to treatment than other staph infections. For example, if a ...

  6. COL4A2 mutations impair COL4A1 and COL4A2 secretion and cause hemorrhagic stroke.

    PubMed

    Jeanne, Marion; Labelle-Dumais, Cassandre; Jorgensen, Jeff; Kauffman, W Berkeley; Mancini, Grazia M; Favor, Jack; Valant, Valerie; Greenberg, Steven M; Rosand, Jonathan; Gould, Douglas B

    2012-01-13

    Collagen, type IV, alpha 1 (COL4A1) and alpha 2 (COL4A2) form heterotrimers and are abundant components of basement membranes, including those of the cerebral vasculature. COL4A1 mutations are an increasingly recognized cause of multisystem disorders, including highly penetrant cerebrovascular disease and intracerebral hemorrhage (ICH). Because COL4A1 and COL4A2 are structurally and functionally associated, we hypothesized that variants in COL4A2 would also cause ICH. We sequence COL4A2 in 96 patients with ICH and identify three rare, nonsynonymous coding variants in four patients that are not present in a cohort of 144 ICH-free individuals. All three variants change evolutionarily conserved amino acids. Using a cellular assay, we show that these putative mutations cause intracellular accumulation of COL4A1 and COL4A2 at the expense of their secretion, which supports their pathogenecity. Furthermore, we show that Col4a2 mutant mice also have completely penetrant ICH and that mutations in mouse and human lead to retention of COL4A1 and COL4A2 within the endoplasmic reticulum (ER). Importantly, two of the three putative mutations found in patients trigger ER stress and activate the unfolded protein response. The identification of putative COL4A2 mutations that might contribute to ICH in human patients provides insight into the pathogenic mechanisms of this disease. Our data suggest that COL4A2 mutations impair COL4A1 and COL4A2 secretion and can also result in cytotoxicity. Finally, our findings suggest that, collectively, mutations in COL4A1 and COL4A2 contribute to sporadic cases of ICH.

  7. Foods from black market at EU border as a neglected route of potential methicillin-resistant Staphylococcus aureus transmission.

    PubMed

    Oniciuc, Elena-Alexandra; Ariza-Miguel, Jaime; Bolocan, Andrei-Sorin; Diez-Valcarce, Marta; Rovira, Jordi; Hernández, Marta; Fernández-Natal, Isabel; Nicolau, Anca Ioana; Rodríguez-Lázaro, David

    2015-09-16

    The illegal entrance of foods to EU through black markets at the EU borders can constitute a neglected route of dissemination of foodborne pathogens, and in particular of methicillin-resistant Staphylococcus aureus (MRSA). In this study, we have assessed the presence of MRSA in foods sold in a black market at an EU border (the southeast part of Romania, on the border with Republic of Moldavia). We performed a search for MRSA among 200 food samples collected from 2012 to 2013. All S. aureus were studied by pulsed-field gel electrophoresis (PFGE) and antimicrobial susceptibility testing. MRSA isolates were further characterized by multilocus sequence typing (MLST) and SCCmec typing, and tested for the presence of Panton-Valentine leukocidin (PVL) virulence factors. Overall, 32 S. aureus isolates were recovered from 16 food samples (8%). One isolate detected in a pork lard sample was MRSA (0.5%). PFGE with the restriction enzyme SmaI revealed 12 genotypes among the 32 S. aureus isolates. The MRSA isolate belonged to sequence type 398, harbored SCCmec type V, tested negative for the presence of the PVL genes and was resistant to ciprofloxacin, tetracycline and cefazolin, besides all β-lactams. Among 31 methicillin-sensitive S. aureus (MSSA), 29% were resistant to penicillin, 9.7% to tetracycline and 3.2% to ciprofloxacin. In conclusion, in this study we report the presence of livestock-associated MRSA in foods sold in a black market at an EU border: ST398-MRSA-V. These results confirm the potential role of food in the dissemination of MRSA lineages among population, and the potential role of illegally introduced food to EU in the prevalence and evolution of MRSA clones in the community.

  8. Evaluation of commercial selective agars in screening for methicillin-resistant Staphylococcus aureus.

    PubMed

    Yang, Hee-Young; Suh, Jin-Tae; Lee, Hee-Joo

    2010-01-01

    To evaluate methicillin-resistant S. aureus (MRSA) detection methods, we compared (a) mannitol salt agar with cefoxitin (MSA-FX), (b) MRSASelect agar (Bio-Rad), (c) MRSA ID (bioMerieuex), and (d) CHROMagar MRSA (BD Diagnostics) as selective media for culturing nasal swab specimens collected from intensive care unit (ICU) patients and healthcare personnel. A total of 99 (17.1%) cases of MRSA were recovered from 578 specimens. Four (5.5%) cases were identified from healthcare personnel and 95 (18.8%) were from ICU patients. The sensitivity of MSA-FX, MRSASelect, MRSA ID, and CHROMagar MRSA was 83.8, 87.9, 80.8, and 84.8% after 18 hr; 92.9, 94.9, 90.9, and 91.9% after 24 hr; and 96.0, 100, 99.0, and 99.0% after 48 hr, respectively. The specificity of MSA-FX, MRSASelect, MRSA ID, and CHROMagar MRSA was 97.7, 99.0, 98.7. and 99.8% after 18 hr; 97.1, 98.5, 98.1, and 99.5% after 24 hr; and 95.2, 97.7, 97.9, and 99.0% after 48 hr, respectively. In conclusion, all four media showed good results after the 24 hr readings, but MRSA ID and CHROMagar MRSA media required readings at 48 hr due to increased sensitivity at this time point.

  9. Population structure analyses of Staphylococcus aureus at Tygerberg Hospital, South Africa, reveals a diverse population, a high prevalence of Panton-Valentine leukocidin genes, and unique local methicillin-resistant S. aureus clones.

    PubMed

    Oosthuysen, W F; Orth, H; Lombard, C J; Sinha, B; Wasserman, E

    2014-07-01

    Studies reporting on the population structure of Staphylococcus aureus in South Africa have focused only on methicillin-resistant S. aureus (MRSA). This study describes the population structure of S. aureus, including methicillin-susceptible S. aureus (MSSA) isolated from patients at Tygerberg Academic Hospital, Western Cape province. Pulsed-field gel electrophoresis (PFGE), detection of Panton-Valentine leukocidin (PVL), spa typing, multilocus sequence typing (MLST), agr typing and SCCmec typing were used to characterize strains. Of 367 non-repetitive S. aureus isolates collected over a period of 1 year, 56 (15.3%) were MRSA. Skin and soft tissue infections were the most frequent source (54.8%), followed by bone and joint (15.3%) and respiratory tract infections (7.7%). For strain typing, PFGE was the most discriminative method, and resulted in 31 pulsotypes (n = 345, 94.0%), as compared with 16 spa clonal complexes (CCs) (n = 344, 93.4%). Four MLST CCs were identified after eBURST of sequence types (STs) of selected isolates. One hundred and sixty isolates (MSSA, n = 155, 42.2%) were PVL-positive, and agr types I-IV and SCCmec types I-V were identified. Our S. aureus population consisted of genotypically diverse strains, with PVL being a common characteristic of MSSA. MSSA and MRSA isolates clustered in different clones. However, the dominant MRSA clone (ST612) also contained an MSSA isolate, and had a unique genotype. Common global epidemic MRSA clones, such as ST239-MRSA-III and ST36-MRSA-II, were identified. A local clone, ST612-MRSA-IV, was found to be the dominant MRSA clone.

  10. Incidence of methicillin-resistant Staphylococcus aureus infection in a children's hospital in the Washington metropolitan area of the United States, 2003 – 2010

    PubMed Central

    Song, Xiaoyan; Cogen, Jonathan; Singh, Nalini

    2013-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) has emerged as a major public health threat. In this retrospective cohort study, we included patients with laboratory-confirmed MRSA infections treated at Children's National Medical Center in Washington, District of Columbia between July 2003 and December 2010. The secular trends in the incidence rates of skin/soft tissue and invasive MRSA infections were assessed. Molecular analyses were performed on a subset of patients with invasive infections whose MRSA isolates were available for genotyping. The study identified 3750 patients with MRSA infections. The incidence of MRSA infections peaked in 2007 (incidence rate: 5.34 per 1000 patient-visits) and subsequently declined at a rate of 5% per year. By December 2010, the MRSA incidence rate reached 3.77 per 1000 patient-visits. Seventeen (14.7%) patients with invasive MRSA infections died, and the mortality risk significantly increased if the MRSA infections were healthcare-associated (HA) or if an isolate was resistant to clindamycin and/or trimethoprim/sulfamethoxazole. In conclusion, this study described a descending trend in MRSA infections in children since 2007. Although invasive MRSA infections only accounted for a small portion of the total MRSA infections, they were associated with a high mortality risk. The prevention and control of the spread of MRSA remains a crucial and challenging task. PMID:26038439

  11. Molecular epidemiology of hospital-onset methicillin-resistant Staphylococcus aureus infections in Southern Chile.

    PubMed

    Medina, G; Egea, A L; Otth, C; Otth, L; Fernández, H; Bocco, J L; Wilson, M; Sola, C

    2013-12-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a pathogen of public health importance. In Chile, the Cordobes/Chilean clone was the predominant healthcare-associated MRSA (HA-MRSA) clone in 1998. Since then, the molecular epidemiological surveillance of MRSA has not been performed in Southern Chile. We aimed to investigate the molecular epidemiology of HA-MRSA infections in Southern Chile to identify the MRSA clones involved, and their evolutionary relationships with epidemic international MRSA lineages. A total of 303 single inpatient isolates of S. aureus were collected in the Valdivia County Hospital (2007-2008), revealing 33% (100 MRSA/303) prevalence for HA-MRSA infections. The SCCmec types I and IV were identified in 97% and 3% of HA-MRSA, respectively. All isolates lacked the pvl genes. A random sample (n = 29) of all MRSA was studied by pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), SCCmec subtyping, agr and spa typing, and virulence genes profiling. PFGE analysis revealed the predominance (89%, 26/29) of pulsotype A and three additional pulsotypes, designated H1, I33, and G1. Pulsotype A (ST5-SCCmecI-spa-t149) is clonally related to the Cordobes/Chilean clone. Pulsotype H1 (ST5-SCCmecIVNT-spa-t002) is genetically related to the Pediatric clone (ST5-SCCmecIV). Pulsotype I33 (ST5-SCCmecIVc-spa-t002) is clonally related by PFGE to the community-associated MRSA (CA-MRSA) clone spread in Argentina, I-ST5-IVa-PVL(+). The G1 pulsotype (ST8-SCCmecIVc-spa-t024) is clonally related to the epidemic USA300 CA-MRSA. Here, we demonstrate the stability of the Cordobes/Chilean clone over time as the major HA-MRSA clone in Southern Chile. The identification of two CA-MRSA clones might suggest that these clones have entered into the healthcare setting from the community. These results emphasize the importance of the local surveillance of MRSA infections in the community and hospital settings.

  12. Foods confiscated from non-EU flights as a neglected route of potential methicillin-resistant Staphylococcus aureus transmission.

    PubMed

    Rodríguez-Lázaro, David; Ariza-Miguel, Jaime; Diez-Valcarce, Marta; Fernández-Natal, Isabel; Hernández, Marta; Rovira, Jordi

    2015-09-16

    The emergence of methicillin-resistant Staphylococcus aureus (MRSA) in food-producing animals has provoked a great concern in the presence of MRSA in associated foodstuff. In this study, we have assessed for the first time the presence of MRSA in food confiscated from non-EU flights. We performed a search for MRSA among 195 food samples confiscated from passengers on flights from twenty-one non-EU countries in 2012 and 2013. One hundred and seventeen meat samples of diverse animal origin (including antelope, beef, chicken, duck, guinea pig, pork, rodents, and turkey), 75 dairy products (74 cheeses and 1 butter) and 3 eggs were analyzed. All S. aureus were studied by pulsed-field gel electrophoresis (PFGE) and antimicrobial susceptibility testing. MRSA isolates were further characterized by multilocus sequence typing (MLST), SCCmec typing, and tested for the presence of Panton-Valentine leukocidin (PVL) virulence factors. Overall, 66 food samples were positive for S. aureus (33.9%). Six S. aureus strains were MRSA (9.1%), all of them in flights from Bolivia (and 5 from the same passenger). Among methicillin-sensitive S. aureus (MSSA) (60 out of 66S. aureus strains), 44.1% were resistant to penicillin, 10.2% to tetracycline, 8.5% were resistant to aminoglycosides (amikacin and tobramycin) and 3.4% exhibited the M phenotype. MRSA isolates were sensitive to all non-β-lactam antibiotics tested. SmaI-PFGE analysis provided 40 genotypes among the S. aureus isolates (three genotypes among the six MRSA). Five MRSA isolates belonged to ST8 and harboured SCCmec type IVc as well as PVL genes. One isolate belonged to ST1649, harboured SCCmec type IVc and tested negative for the presence of the PVL genes. In conclusion, in this study, we report for the first time the presence of CA-MRSA in food confiscated from non-EU flights: ST8/ST1649-MRSA-IV. These results confirm the illegal entrance of food as a neglected route of transmission as well as the dissemination of successful CA-MRSA

  13. Colonization of Cimex lectularius with methicillin-resistant Staphylococcus aureus.

    PubMed

    Barbarin, Alexis M; Hu, Baofeng; Nachamkin, Irving; Levy, Michael Z

    2014-05-01

    A recent paper published by Lowe and Romney in Emerging Infectious Diseases titled, Bed bugs as Vectors for Drug-Resistant Bacteria has sparked a renewed interest in bed bug vector potential. We followed a pyrethroid resistant strain of the human bed bug (Cimex lectularius, L.) fed either human blood or human blood with added methicillin resistant Staphylococcus aureus (MRSA) for 9 days post-feeding. Results indicated that while the bed bug midgut is a hospitable environment for MRSA, the bacteria does not survive longer than 9 days within the midgut. Additionally, MRSA is not amplified within the midgut of the bug as the infection was cleared within 9 days. Due to the weekly feeding behaviours of bed bugs, these results suggest that bed bug transmission of MRSA is highly unlikely.

  14. Molecular Characterization of Staphylococcus aureus Isolates Transmitted between Patients with Buruli Ulcer

    PubMed Central

    Amissah, Nana Ama; Chlebowicz, Monika A.; Ablordey, Anthony; Sabat, Artur J.; Tetteh, Caitlin S.; Prah, Isaac; van der Werf, Tjip S.; Friedrich, Alex W.; van Dijl, Jan Maarten

    2015-01-01

    Background Buruli ulcer (BU) is a skin infection caused by Mycobacterium ulcerans. The wounds of most BU patients are colonized with different microorganisms, including Staphylococcus aureus. Methodology This study investigated possible patient-to-patient transmission events of S. aureus during wound care in a health care center. S. aureus isolates from different BU patients with overlapping visits to the clinic were whole-genome sequenced and analyzed by a gene-by-gene approach using SeqSphere+ software. In addition, sequence data were screened for the presence of genes that conferred antibiotic resistance. Principal Findings SeqSphere+ analysis of whole-genome sequence data confirmed transmission of methicillin resistant S. aureus (MRSA) and methicillin susceptible S. aureus among patients that took place during wound care. Interestingly, our sequence data show that the investigated MRSA isolates carry a novel allele of the fexB gene conferring chloramphenicol resistance, which had thus far not been observed in S. aureus. PMID:26360794

  15. Antibacterial Activity of Mulinum spinosum Extracts against Slime-Producing Staphylococcus aureus and Methicillin-Resistant Staphylococcus aureus Isolated from Nasal Carriers

    PubMed Central

    Daniela, Echenique; Alejandra, Chiaramello; Pedro, Rossomando; Claudia, Mattana; Lucía, Alcaráz; Carlos, Tonn; Analía, Laciar; Sara, Satorres

    2014-01-01

    Nasal carriers of Staphylococcus aureus are important reservoirs with risk of developing endogenous infections or transmitting infections to susceptible individuals. Methicillin-resistant S. aureus (MRSA) are associated with higher rates of treatment failure. Some strains of S. aureus produce slime which is believed to make the microorganisms more resistant to antibiotics and host defenses. The antibacterial activity of ethyl acetate : n-hexane (EtOAc : HEX) extracts of Mulinum spinosum (5 : 95% EtOAc : HEX, 50 : 50% EtOAc : HEX, 70 : 30% EtOAc : HEX and mix 20 : 80/30 : 70% EtOAc : HEX, 50 : 50/70 : 30/100 : 0% EtOAc : HEX) were assayed against 3 slime-producing S. aureus strains and 2 MRSA strains isolated from nasal carriers. S. aureus ATCC 35556 slime-producing strain and MRSA ATCC 43300 strain were used as controls. The extracts were prepared using flash chromatography. M. spinosum 5 : 95% AcOEt : HEX showed antibacterial effect against all slime-producing strains (MIC: 500 µg/mL) and the highest activity against MRSA strains (MIC: 500 to 1000 µg/mL). All M. spinosum extracts assayed were active against slime-producing S. aureus and MRSA at doses between 500 and 4000 µg/mL. Both, slime-producing S. aureus and MRSA are highly contagious and hardly eradicated by antibiotic therapies. So, there is an increasing need to find new substances with the ability to inhibit these strains. PMID:25530997

  16. Staphylococcus aureus Nasal Carriage among Beefpacking Workers in a Midwestern United States Slaughterhouse

    PubMed Central

    Leibler, Jessica H.; Jordan, Jeanne A.; Brownstein, Kirsten; Lander, Lina; Price, Lance B.; Perry, Melissa J.

    2016-01-01

    Occupational contact with livestock is an established risk factor for exposure to livestock-associated methicillin-resistant Staphylococcus aureus (MRSA), particularly among industrial swine workers. While S. aureus is known to infect cattle, livestock-associated S. aureus carriage among workers in the beef production chain has received limited attention. Beefpacking workers, who slaughter, butcher and process cattle, have intensified exposure to potentially infectious animal materials and may be at risk of livestock-associated S. aureus exposure. We conducted a cross-sectional study of beefpacking workers (n = 137) at an industrial slaughterhouse in the Midwestern United States to evaluate prevalence and characteristics of S. aureus nasal colonization, specifically the absence of the scn gene to identify putative association with livestock, antibiotic susceptibility, presence of Panton-Valentin leukocidin (PVL) genes lukS-PV and lukF-PV, and spa type. Overall prevalence of S. aureus nasal carriage was 27.0%. No workers carried livestock-associated MRSA. Methicillin-sensitive S. aureus isolates (MSSA) recovered from five workers (3.6%) lacked the scn gene and were considered putative livestock-associated S. aureus (pLA-SA). Among pLA-SA isolates, spa types t338, t748, t1476 and t2379 were identified. To our knowledge, these spa types have not previously been identified as associated with livestock. Prevalence of human-adapted MRSA carriage in workers was 3.6%. MRSA isolates were identified as spa types t002, t008 and t024, and four of five MRSA isolates were PVL-positive. To date, this is the first study to indicate that industrial beefpacking workers in the United States may be exposed to livestock-associated S. aureus, notably MSSA, and to spa types not previously identified in livestock and livestock workers. Occupational exposure to livestock-associated S. aureus in the beef production chain requires further epidemiologic investigation. PMID:26866374

  17. Staphylococcus aureus Nasal Carriage among Beefpacking Workers in a Midwestern United States Slaughterhouse.

    PubMed

    Leibler, Jessica H; Jordan, Jeanne A; Brownstein, Kirsten; Lander, Lina; Price, Lance B; Perry, Melissa J

    2016-01-01

    Occupational contact with livestock is an established risk factor for exposure to livestock-associated methicillin-resistant Staphylococcus aureus (MRSA), particularly among industrial swine workers. While S. aureus is known to infect cattle, livestock-associated S. aureus carriage among workers in the beef production chain has received limited attention. Beefpacking workers, who slaughter, butcher and process cattle, have intensified exposure to potentially infectious animal materials and may be at risk of livestock-associated S. aureus exposure. We conducted a cross-sectional study of beefpacking workers (n = 137) at an industrial slaughterhouse in the Midwestern United States to evaluate prevalence and characteristics of S. aureus nasal colonization, specifically the absence of the scn gene to identify putative association with livestock, antibiotic susceptibility, presence of Panton-Valentin leukocidin (PVL) genes lukS-PV and lukF-PV, and spa type. Overall prevalence of S. aureus nasal carriage was 27.0%. No workers carried livestock-associated MRSA. Methicillin-sensitive S. aureus isolates (MSSA) recovered from five workers (3.6%) lacked the scn gene and were considered putative livestock-associated S. aureus (pLA-SA). Among pLA-SA isolates, spa types t338, t748, t1476 and t2379 were identified. To our knowledge, these spa types have not previously been identified as associated with livestock. Prevalence of human-adapted MRSA carriage in workers was 3.6%. MRSA isolates were identified as spa types t002, t008 and t024, and four of five MRSA isolates were PVL-positive. To date, this is the first study to indicate that industrial beefpacking workers in the United States may be exposed to livestock-associated S. aureus, notably MSSA, and to spa types not previously identified in livestock and livestock workers. Occupational exposure to livestock-associated S. aureus in the beef production chain requires further epidemiologic investigation.

  18. Characterization of Staphylococcus aureus Isolates That Colonize Medical Students in a Hospital of the City of Cali, Colombia

    PubMed Central

    Collazos Marín, Luis Fernando; Estupiñan Arciniegas, Gina; Chavez Vivas, Monica

    2015-01-01

    Introduction. Nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) represents a risk for the spread of bacteria. This study characterized the S. aureus isolated from medical students, who were in their clinical rotation at a hospital in the city of Cali. Materials and Methods. 216 students participated in the study and 63 isolates of S. aureus were evaluated for susceptibility and PCR amplification of agr and mecA genes. The origin of MRSA isolates was established by analyzing agr polymorphisms. Results. A total of 29.2% of students were colonized by S. aureus and nasal carriage rate was 23.6% and 14.3% MRSA. Three agr groups (agr II, and agr III) were identified; the agr I group was the most common, with a 35% prevalence; this group is from community origin. Conclusion. The present study demonstrates that medical students carry S. aureus strains, with the threat of spreading them both to community and hospital environments. PMID:26495001

  19. Utilizing Moist or Dry Swabs for the Sampling of Nasal MRSA Carriers? An In Vivo and In Vitro Study

    PubMed Central

    Warnke, Philipp; Devide, Annette; Weise, Mirjam; Frickmann, Hagen; Schwarz, Norbert Georg; Schäffler, Holger; Ottl, Peter; Podbielski, Andreas

    2016-01-01

    This study investigates the quantitative bacterial recovery of Methicillin-resistant Staphylococcus aureus (MRSA) in nasal screenings by utilizing dry or moistened swabs within an in vivo and an in vitro experimental setting. 135 nasal MRSA carriers were each swabbed in one nostril with a dry and in the other one with a moistened rayon swab. Quantitative bacterial recovery was measured by standard viable count techniques. Furthermore, an anatomically correct artificial nose model was inoculated with a numerically defined suspension of MRSA and swabbed with dry and moistened rayon, polyurethane-foam and nylon-flocked swabs to test these different settings and swab-materials under identical laboratory conditions. In vivo, quantities of MRSA per nostril in carriers varied between <101 and >107 colony forming units, with a median of 2.15x104 CFU. However, no statistically significant differences could be detected for the recovery of MRSA quantities when swabbing nasal carriers with moist or dry rayon swabs. In vitro testing confirmed the in vivo data for swabs with rayon, polyurethane and nylon-flocked tips, since pre-moistening of swabs did not significantly affect the quantities of retrieved bacteria. Therefore, pre-moistening of swabs prior to nasal MRSA sampling provides no advantage in terms of recovering greater bacterial quantities and therefore can be omitted. In addition, this situation can be mimicked in an in vitro model, thereby providing a useful basis for future in vitro testings of new swab types or target organisms for screening approaches. PMID:27626801

  20. The Nonantibiotic Small Molecule Cyslabdan Enhances the Potency of β-Lactams against MRSA by Inhibiting Pentaglycine Interpeptide Bridge Synthesis

    PubMed Central

    Koyama, Nobuhiro; Tokura, Yuriko; Münch, Daniela; Sahl, Hans-Georg; Schneider, Tanja; Shibagaki, Yoshio; Ikeda, Haruo; Tomoda, Hiroshi

    2012-01-01

    The nonantibiotic small molecule cyslabdan, a labdan-type diterpene produced by Streptomyces sp. K04-0144, markedly potentiated the activity of the β-lactam drug imipenem against methicillin-resistant Staphylococcus aureus (MRSA). To study the mechanism of action of cyslabdan, the proteins that bind to cyslabdan were investigated in an MRSA lysate, which led to the identification of FemA, which is involved in the synthesis of the pentaglycine interpeptide bridge of the peptidoglycan of MRSA. Furthermore, binding assay of cyslabdan to FemB and FemX with the function similar to FemA revealed that cyslabdan had an affinity for FemB but not FemX. In an enzyme-based assay, cyslabdan inhibited FemA activity, where as did not affected FemX and FemB activities. Nonglycyl and monoglycyl murein monomers were accumulated by cyslabdan in the peptidoglycan of MRSA cell walls. These findings indicated that cyslabdan primarily inhibits FemA, thereby suppressing pentaglycine interpeptide bridge synthesis. This protein is a key factor in the determination of β-lactam resistance in MRSA, and our findings provide a new strategy for combating MRSA. PMID:23166602

  1. Building a genomic framework for prospective MRSA surveillance in the United Kingdom and the Republic of Ireland.

    PubMed

    Reuter, Sandra; Török, M Estée; Holden, Matthew T G; Reynolds, Rosy; Raven, Kathy E; Blane, Beth; Donker, Tjibbe; Bentley, Stephen D; Aanensen, David M; Grundmann, Hajo; Feil, Edward J; Spratt, Brian G; Parkhill, Julian; Peacock, Sharon J

    2016-02-01

    The correct interpretation of microbial sequencing data applied to surveillance and outbreak investigation depends on accessible genomic databases to provide vital genetic context. Our aim was to construct and describe a United Kingdom MRSA database containing over 1000 methicillin-resistant Staphylococcus aureus (MRSA) genomes drawn from England, Northern Ireland, Wales, Scotland, and the Republic of Ireland over a decade. We sequenced 1013 MRSA submitted to the British Society for Antimicrobial Chemotherapy by 46 laboratories between 2001 and 2010. Each isolate was assigned to a regional healthcare referral network in England and was otherwise grouped based on country of origin. Phylogenetic reconstructions were used to contextualize MRSA outbreak investigations and to detect the spread of resistance. The majority of isolates (n = 783, 77%) belonged to CC22, which contains the dominant United Kingdom epidemic clone (EMRSA-15). There was marked geographic structuring of EMRSA-15, consistent with widespread dissemination prior to the sampling decade followed by local diversification. The addition of MRSA genomes from two outbreaks and one pseudo-outbreak demonstrated the certainty with which outbreaks could be confirmed or refuted. We identified local and regional differences in antibiotic resistance profiles, with examples of local expansion, as well as widespread circulation of mobile genetic elements across the bacterial population. We have generated a resource for the future surveillance and outbreak investigation of MRSA in the United Kingdom and Ireland and have shown the value of this during outbreak investigation and tracking of antimicrobial resistance.

  2. Review on Panton Valentine leukocidin toxin carriage among Staphylococcus aureus.

    PubMed

    Shrestha, B

    2013-09-01

    Panton Valentine leukocidin is a toxin making pores in the polymorphonuclear cells which is a virulence factor of some strains of Staphylococcus aureus. Initially it was produced by methicillin susceptible Staphylococcus aureus only. Later with the acquisition of mecA gene has lead it to be PVL positive methicillin resistant Staphylococcus aureus. Since MRSA are resistant to many antibiotics and further they produce a toxin the infections by PVL positive MRSA has become a challenge. PVL positive MRSA a virulent strain of drug resistant superbug MRSA that has spread around the world, has claimed many lives in UK, Europe, USA and Australia. Some strains of superbug attack the healthy young people and kill within 24 hrs. PVL positive Staphylococcus aureus has been reported to be associated with skin and soft tissue infections however they also cause invasive infections and necrotizing pneumonia. These microorganisms known to be community associated have spread to hospitals. Hospital acquired infection by such microorganisms lead to an increase in mortality hence should be controlled before they become prevalent in hospitals.

  3. Comparative phenotypic and genotypic discrimination of methicillin resistant and susceptible Staphylococcus aureus in Egypt.

    PubMed

    Abd El-Hamid, Marwa I; Bendary, M M

    2015-09-26

    The present study was designed to elucidate the phenotypic and genotypic characterization of S. aureus isolates in Egypt. The antibiotic susceptibility pattern of 133 identified S. aureus isolates revealed that over 70% of the isolates were multi-drug resistant (MDR). Fifty MDR isolates were characterized using antibiotyping and different molecular typing methods. Amplification of mecA gene confirmed 30 strains as methicillin-resistant S. aureus (MRSA) and 20 as methicillin-sensitive S. aureus (MSSA). Generally, 22 MRSA (73.33%) and ten MSSA (50%) harbored Panton-Valentine leukocidin (pvl) gene with no statistically significant difference (p=0.093). Staphylococcal cassette chromosome (SCC) mec typing revealed that 48% of the typeable MRSA isolates possessed SCCmec type IV. SCCmec and antimicrobial susceptibility typing signified the presence of community-acquired (CA)-MRSA in Egypt. Surprisingly, all isolates of SCCmec types I, II and III and 50% of both MRSA isolates of SCCmec types IV and V possessed pvl gene. It was clear that staphylococcal protein A (spa) and coagulase (coa) typing discriminated the isolates into eight different groups, whilst polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) of coagulase gene yielded ten distinct RFLP banding patterns. This study presented the first baseline information on the characterization of MRSA and MSSA in Egypt.

  4. Disorganization of cell division of methicillin-resistant Staphylococcus aureus by methanolic extract from Phyllanthus columnaris stem bark

    SciTech Connect

    Adnalizawati, A. Siti Noor; Nazlina, I.; Yaacob, W. A.

    2013-11-27

    The in vitro activity of methanolic extract from Phyllanthus columnaris stem bark was studied against Methicillin-resistant Staphylococcus aureus (MRSA) ATCC 43300 and MRSA BM1 (clinical strain) using time-kill curves in conjunction with scanning and transmission electron microscopy. The extract showed more markedly bactericidal activity in MRSA BM1 clinical strain within less than 4 h by 6.25-12.5 mg/mL and within 6 h by 1.56 mg/mL. Scanning electron microscopy of MRSA BM1 revealed distortion of cell whilst transmission electron microscopy revealed disruption in cell wall division.

  5. Disorganization of cell division of methicillin-resistant Staphylococcus aureus by methanolic extract from Phyllanthus columnaris stem bark

    NASA Astrophysics Data System (ADS)

    Adnalizawati, A. Siti Noor; Nazlina, I.; Yaacob, W. A.

    2013-11-01

    The in vitro activity of methanolic extract from Phyllanthus columnaris stem bark was studied against Methicillin-resistant Staphylococcus aureus (MRSA) ATCC 43300 and MRSA BM1 (clinical strain) using time-kill curves in conjunction with scanning and transmission electron microscopy. The extract showed more markedly bactericidal activity in MRSA BM1 clinical strain within less than 4 h by 6.25-12.5 mg/mL and within 6 h by 1.56 mg/mL. Scanning electron microscopy of MRSA BM1 revealed distortion of cell whilst transmission electron microscopy revealed disruption in cell wall division.

  6. A study of the prevalence of methicillin-resistant Staphylococcus aureus in dermatology inpatients

    PubMed Central

    Vijayamohan, N.; Nair, S. Pradeep

    2014-01-01

    Background: Methicillin-resistant Staphylococcus aureus (MRSA) is a cause of increased morbidity and mortality in debilitated and immunocompromised patients. Aims and Objectives: To study the prevalence of MRSA among dermatology inpatients and elucidate its predisposing factors and antibiotic sensitivity pattern. Materials and Methods: This prospective study involved all the inpatients in the dermatology ward with suspected bacterial infections, both primary and secondary. Gram's stain, pus culture, and antibiotic sensitivity were the main tests done. Results: There were 61 patients in this study, with 36 males (59%) and 25 females (41%). The age group maximally affected was 41-50 years (21.6%). Vesiculobullous disorders (22, 36.1%) and eczemas (16, 26.2%) were the commonest dermatoses with secondary infection. Extremities (72.1%) and the trunk (26.2%) were the commonest sites involved. Diabetes mellitus (DM) was the commonest systemic illness (11.5%). Staphylococcus aureus was the commonest isolate, grown in 52 patients (85.2%) of whom 16 (30.80%) were MRSA positive. MRSA constituted 22.2% of the total bacterial isolates. All the MRSA isolates (100%) were resistant to cloxacillin and oxacillin, while all the isolates (100%) were sensitive to vancomycin and linezolid. Conclusions: The prevalence of MRSA in this study was high. It was most commonly seen in patients with vesiculobullous disorders. A high sensitivity of MRSA was found to amikacin. There was no relation between prolonged antibiotic therapy and MRSA in this study. PMID:25396125

  7. Molecular characterization of methicillin-resistant Staphylococcus aureus strains from pet animals and veterinary staff in China.

    PubMed

    Zhang, Wanjiang; Hao, Zhihui; Wang, Yang; Cao, Xingyuan; Logue, Catherine M; Wang, Bing; Yang, Jing; Shen, Jianzhong; Wu, Congming

    2011-11-01

    The aim of this study was to determine the epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) isolates from pet animals and veterinary staff and the characteristics of these isolates. A total of 22 MRSA isolates were isolated from nasal swabs from dogs, cats and veterinary staff in six pet hospitals in six cities, and examined for antimicrobial susceptibility, the presence of resistance genes, Panton-Valentine leukocidin gene lukF-lukS, staphylococcal chromosomal cassette (SCC) mec typing, spa tying, pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing. Of 22 MRSA isolates, 21 were recovered from pet animals, and one was isolated from a member of sstaff. All 22 MRSA strains were resistant to penicillin, oxacillin, azithromycin, clindamycin and ceftriaxone, and harboured mecA, ermB and linA genes. The lukF-lukS gene was not detected in any of the MRSA isolates. Eighteen MRSA strains from Qingdao belonged to ST59-MRSA-IV-spa t437. Of four MRSA isolates from Beijing, one belonged to ST398-MRSA-V-spa t034, and three belonged to ST239-MRSA-III-spa t030 profiles. Two PFGE types (A and B) were identified. Two isolates originating from dogs and one isolate originating from a staff member in Beijing shared similar PFGE patterns. Our cumulative data suggested that cross-transmission of MRSA may have occurred between pet animals and veterinary staff.

  8. Individual Predisposition to Staphylococcus aureus Colonization in Pigs on the Basis of Quantification, Carriage Dynamics, and Serological Profiles

    PubMed Central

    Espinosa-Gongora, Carmen; Dahl, Jan; Elvstrøm, Anders; van Wamel, Willem J.

    2014-01-01

    Previous research on Staphylococcus aureus in pigs focused on livestock-associated methicillin-resistant S. aureus (MRSA) and had a qualitative cross-sectional design. This study aimed to elucidate the frequency, load, and stability of S. aureus nasal carriage in pigs over time and investigated possible associations between carriage and immune response. Nasal swabs were collected three times weekly from 480 tagged adult pigs in 20 Danish production farms. S. aureus and MRSA were quantified on selective media by the most-probable-number method. The levels of IgG against 10 S. aureus antigens in serum were quantified in selected pigs by a Luminex assay. All the farms were positive for S. aureus and 15 for MRSA, leading to overall prevalences of persistent and intermittent carriers and noncarriers of 24, 52, and 23%, respectively. Carriage frequency and nasal loads were significantly higher on MRSA-positive farms. Logistic-regression modeling revealed the presence of individual pigs characterized by high nasal loads (≥10,000 CFU per swab) and stable carriage regardless of farm- and pen-associated factors. On the other hand, the humoral response was strongly influenced by these environmental factors. The existence of a minority of shedders contributing to maintenance of S. aureus within farms opens up new perspectives on the control of MRSA in pig farming. PMID:25501475

  9. Evolutionarily distinct bacteriophage endolysins featuring conserved peptidoglycan cleavage sites protect mice from MRSA infection

    PubMed Central

    Schmelcher, Mathias; Shen, Yang; Nelson, Daniel C.; Eugster, Marcel R.; Eichenseher, Fritz; Hanke, Daniela C.; Loessner, Martin J.; Dong, Shengli; Pritchard, David G.; Lee, Jean C.; Becker, Stephen C.; Foster-Frey, Juli; Donovan, David M.

    2015-01-01

    Objectives In the light of increasing drug resistance in Staphylococcus aureus, bacteriophage endolysins [peptidoglycan hydrolases (PGHs)] have been suggested as promising antimicrobial agents. The aim of this study was to determine the antimicrobial activity of nine enzymes representing unique homology groups within a diverse class of staphylococcal PGHs. Methods PGHs were recombinantly expressed, purified and tested for staphylolytic activity in multiple in vitro assays (zymogram, turbidity reduction assay and plate lysis) and against a comprehensive set of strains (S. aureus and CoNS). PGH cut sites in the staphylococcal peptidoglycan were determined by biochemical assays (Park–Johnson and Ghuysen procedures) and MS analysis. The enzymes were tested for their ability to eradicate static S. aureus biofilms and compared for their efficacy against systemic MRSA infection in a mouse model. Results Despite similar modular architectures and unexpectedly conserved cleavage sites in the peptidoglycan (conferred by evolutionarily divergent catalytic domains), the enzymes displayed varying degrees of in vitro lytic activity against numerous staphylococcal strains, including cell surface mutants and drug-resistant strains, and proved effective against static biofilms. In a mouse model of systemic MRSA infection, six PGHs provided 100% protection from death, with animals being free of clinical signs at the end of the experiment. Conclusions Our results corroborate the high potential of PGHs for treatment of S. aureus infections and reveal unique antimicrobial and biochemical properties of the different enzymes, suggesting a high diversity of potential applications despite highly conserved peptidoglycan target sites. PMID:25630640

  10. Epidemiology of Staphylococcus aureus in Italy: First nationwide survey, 2012.

    PubMed

    Campanile, Floriana; Bongiorno, Dafne; Perez, Marianna; Mongelli, Gino; Sessa, Laura; Benvenuto, Sabrina; Gona, Floriana; Varaldo, Pietro E; Stefani, Stefania

    2015-12-01

    A 3-month epidemiological study to determine the prevalence and antibiotic resistance of Staphylococcus aureus nosocomial infections was performed in 52 centres throughout Italy in 2012. A total of 21,873 pathogens were analysed. The prevalence of S. aureus among all nosocomial pathogens isolated in that period was 11.6% (n=2541), whilst the prevalence of methicillin-resistant S. aureus (MRSA) among the S. aureus was 35.8% (n=910). All tested antimicrobials demonstrated ≥92.2% susceptibility against methicillin-susceptible S. aureus, with the exception of clindamycin (89.7%) and erythromycin (84.2%). Among MRSA, percentages of resistance ranged from 12.6% to >39% for tetracycline, rifampicin, clindamycin and gentamicin; higher percentages were found for erythromycin (65.4%) and fluoroquinolones (72.3-85.8%). Overall, the glycopeptide minimum inhibitory concentration (MIC) distribution showed that 58.3% of strains possessed MICs of 1-2mg/L and few strains were linezolid- or daptomycin-resistant. Molecular characterisation was performed on 102 MRSA selected from Northern, Central and Southern regions. Five major clones were found: Italian/ST228-I (t001-t023-t041-t1686-t3217), 33.3%; USA500/ST8-IV (t008), 17.6%; E-MRSA15/ST22-IVh (t020-t025-t032-t223), 16.7%; USA100/ST5-II (t002-t653-t1349-t2164-t3217-t388), 14.7%; and Brazilian/ST239/241-III (t030-t037), 3.9%. Five PVL-positive CA-MRSA isolates, belonging to USA300 and minor clones, were also identified. In conclusion, this first nationwide surveillance study showed that in Italy, S. aureus infections accounted for 11.6% of all nosocomial infections; MRSA accounted for approximately one-third of the S. aureus isolates and these were multidrug-resistant organisms. Five major MRSA epidemic clones were observed and were inter-regionally distributed, with ST228-SCCmecI becoming predominant.

  11. Association between antimicrobial consumption and clinical isolates of methicillin-resistant Staphylococcus aureus: a 14-year study.

    PubMed

    Nakamura, Ayako; Miyake, Kazunori; Misawa, Shigeki; Kuno, Yutaka; Horii, Takashi; Hori, Satoshi; Kondo, Shigemi; Tabe, Yoko; Ohsaka, Akimichi

    2012-02-01

    The objective of this study was to determine the relationship between clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and antimicrobial consumption in hospitalized patients over a 14-year period. The study was retrospectively conducted between January 1995 and December 2008 at Juntendo University Hospital, Tokyo, Japan, a 1,020-bed tertiary-care teaching hospital. The incidence of MRSA isolates was examined using clinical specimens presented to the microbiology laboratory in the hospital. Antimicrobial consumption through intravenous injection was calculated in terms of the number of defined daily doses per 100 bed-days. The correlation between the incidence of MRSA isolates and antimicrobial consumption was determined employing a multiple stepwise regression analysis. A total of 109,946 bacterial isolates were consecutively collected over the 14-year period, and, of these, 13,872 (64% of S. aureus strains excluding coagulase-negative staphylococci) were MRSA strains. The longitudinal observation showed that the number and rate of MRSA isolates marginally decreased. The rate of MRSA isolates among S. aureus strains in 1995 was 68.5%, whereas that in 2008 was 53.8%. Consumption of cephalosporins decreased. Among carbapenems, the rate of imipenem (IPM) consumption decreased, whereas that of meropenem increased. A multiple stepwise regression analysis revealed that the antimicrobial consumption of cefmetazole, cefotiam, and IPM was positively correlated with the incidence of MRSA isolates. The use of β-lactam antimicrobials may contribute to the development of MRSA strains.

  12. Isolation and characterization of methicillin-resistant Staphylococcus aureus from pork farms and visiting veterinary students.

    PubMed

    Frana, Timothy S; Beahm, Aleigh R; Hanson, Blake M; Kinyon, Joann M; Layman, Lori L; Karriker, Locke A; Ramirez, Alejandro; Smith, Tara C

    2013-01-01

    In the last decade livestock-associated methicillin-resistant S. aureus (LA-MRSA) has become a public health concern in many parts of the world. Sequence type 398 (ST398) has been the most commonly reported type of LA-MRSA. While many studies have focused on long-term exposure experienced by swine workers, this study focuses on short-term exposures experienced by veterinary students conducting diagnostic investigations. The objectives were to assess the rate of MRSA acquisition and longevity of carriage in students exposed to pork farms and characterize the recovered MRSA isolates. Student nasal swabs were collected immediately before and after farm visits. Pig nasal swabs and environmental sponge samples were also collected. MRSA isolates were identified biochemically and molecularly including spa typing and antimicrobial susceptibility testing. Thirty (30) veterinary students were enrolled and 40 pork farms were visited. MRSA was detected in 30% of the pork farms and in 22% of the students following an exposure to a MRSA-positive pork farm. All students found to be MRSA-positive initially following farm visit were negative for MRSA within 24 hours post visit. Most common spa types recovered were t002 (79%), t034 (16%) and t548 (4%). Spa types found in pork farms closely matched those recovered from students with few exceptions. Resistance levels to antimicrobials varied, but resistance was most commonly seen for spectinomycin, tetracyclines and neomycin. Non-ST398 MRSA isolates were more likely to be resistant to florfenicol and neomycin as well as more likely to be multidrug resistant compared to ST398 MRSA isolates. These findings indicate that MRSA can be recovered from persons visiting contaminated farms. However, the duration of carriage w