Microbial drug resistance : MDR : mechanisms, epidemiology, and disease
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Microb. Drug Resist. · Oct 2015
The Prevalence of Vancomycin-Intermediate Staphylococcus aureus and Heterogeneous VISA Among Methicillin-Resistant Strains Isolated from Pediatric Population in a Turkish University Hospital.
There are limited data regarding the prevalence of vancomycin-intermediate Staphylococcus aureus (VISA)/heterogeneous VISA (hVISA) among pediatric population. Our objective was to determine the distribution of vancomycin and daptomycin minimum inhibitory concentrations (MICs) and explore the phenomenon of vancomycin MIC creep and the VISA/hVISA prevalence among the methicillin-resistant Staphylococcus aureus (MRSA) strains belonging to pediatric population by population analysis profile-area under the curve (PAP-AUC) and Etest macromethod. Vancomycin and daptomycin susceptibilities of 94 pediatric isolates of MRSA were tested by broth microdilution (BMD) and Etest methods. ⋯ To our knowledge, this is the first study investigating the prevalence of VISA/hVISA among MRSA isolated from pediatric patients by PAP-AUC method. Based on our findings, MRSA isolates, which have vancomycin MIC of 2 μg/ml can be investigated for the presence of hVISA. In this study, daptomycin showed potent activity against all isolates and may represent a therapeutic option for MRSA infections.
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Microb. Drug Resist. · Oct 2015
Biocide Susceptibility of Staphylococcus aureus CC398 and CC30 Isolates from Pigs and Identification of the Biocide Resistance Genes, qacG and qacC.
Methicillin-resistant Staphylococcus aureus (MRSA), in particular clonal complex (CC) 398, is increasingly found in livestock. Recently, MRSA CC30 was identified in Danish pigs. We determined the susceptibility of porcine S. aureus isolates of CC398 and CC30 to disinfectants used in pig farming (benzalkonium chloride, hydrogen peroxide, formaldehyde, sodium hypochlorite, and caustic soda). Furthermore, efflux pump activity, antimicrobial resistance profiles, hemolysis properties, and the presence of toxic shock syndrome toxin-1 (TSST-1) and Panton-Valentine Leukocidin (PVL)-encoding virulence factors were investigated. ⋯ The presence of qac genes in European porcine S. aureus isolates and in livestock-associated MRSA CC30 is for the first time described in this study. This finding is concerning as it ultimately may compromise disinfection with QACs and thereby contribute to the selection and spread of MRSA CC30.
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Microb. Drug Resist. · Aug 2015
Synergistic Effects Between Thioxanthones and Oxacillin Against Methicillin-Resistant Staphylococcus aureus.
The extensive use of antimicrobials is leaving medicine with few effective therapeutic options to treat many infections due to the fact that many organisms developed resistance to commonly used drugs. It is therefore pertinent to search not only for new antimicrobials but also for compounds able to restore or potentiate the activity of existing antibiotics. We have screened a library consisting of 40 (thio)xanthone derivatives for antibacterial activity and possible synergistic effects when used in combination with antibiotics. ⋯ Subsequently, docking simulations between thioxanthones 9 and 10 and the allosteric domain of penicillin-binding protein 2A (PBP2A) were undertaken in AutoDock Vina. Both compounds had the ability to bind with an allosteric domain of PBP2A, which may explain their synergy with oxacillin. These two thioxanthone derivatives with different profiles may be promising tools for restoring the activity of oxacillin against MRSA.
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Microb. Drug Resist. · Jun 2015
Emergence of Carbapenem-Resistant Pseudomonas aeruginosa and Acinetobacter baumannii Clinical Isolates Collected from Some Libyan Hospitals.
The aim of the present study was to investigate the molecular mechanism of carbapenem resistance in Pseudomonas aeruginosa and Acinetobacter baumannii clinical isolates recovered from Libyan hospitals between April 2013 and April 2014. In total, 49 strains (24 P. aeruginosa and 25 A. baumannii) were isolated, including 21 P. aeruginosa and 22 A. baumannii isolates (87.75%) resistant to imipenem (minimum inhibitory concentrations ≥16 μg/ml). The blaVIM-2 gene was detected in 19 P. aeruginosa isolates. ⋯ This study is the first report describing imipenem-resistant P. aeruginosa and A. baumannii isolated from patients in Libya. We report the first case of co-occurrence of blaVIM-2 with oprD porin loss in identical isolates of P. aeruginosa in Libya and demonstrate that these oprD mutations can be used as a tool to study the clonality in P. aeruginosa isolates. We also report the first identification of multidrug-resistant A. baumannii isolates harboring blaOXA-23-like, blaOXA-24-like, and blaOXA-48-like genes in Libya.
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Microb. Drug Resist. · Jun 2015
Molecular characterization of carbapenemase production among gram-negative bacteria in saudi arabia.
We characterized the molecular basis of carbapenemase production in carbapenem-resistant Gram-negative bacteria isolated from hospitalized patients from Saudi Arabia in the year 2012. Isolates were collected from across the Kingdom and phenotypically tested for carbapenemase production. Polymerase chain reaction detection of carbapenemase genes was also performed. ⋯ Our study is the first report of OXA-48, NDM-1, and VIM-4 enzymes in Enterobacter from the Kingdom. Also it is the first report of OXA-72 and NDM-1 in A. baumannii in Saudi Arabia, and the coexistence of blaOXA-23 and blaNDM-1 genes in this species in the country. Awareness of the role of international travel in the spread of carbapenem-resistant determinants in the Kingdom, as well as effective infection control interventions in hospitals and strict antimicrobial stewardship in healthcare facilities and the community are keys to combat the rise of carbapenemase producers in the Kingdom.