1. Molecular Markers of Antimicrobial Resistance in Methicillin-Resistant Staphylococcus aureus SCCmec IV Presenting Different Genetic Backgrounds.
- Author
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de Matos PD, de Oliveira TL, Cavalcante FS, Ferreira DC, Iorio NL, Pereira EM, Chamon RC, and Dos Santos KR
- Subjects
- Anti-Bacterial Agents pharmacology, Bacterial Typing Techniques, Brazil epidemiology, DNA Topoisomerase IV metabolism, Hospitals, Humans, Lincosamides pharmacology, Macrolides pharmacology, Methicillin-Resistant Staphylococcus aureus drug effects, Methicillin-Resistant Staphylococcus aureus growth & development, Methicillin-Resistant Staphylococcus aureus isolation & purification, Methionine Sulfoxide Reductases metabolism, Methyltransferases metabolism, Microbial Sensitivity Tests, Molecular Epidemiology, Mutation, Quinolones pharmacology, Staphylococcal Infections drug therapy, Staphylococcal Infections epidemiology, Staphylococcal Infections microbiology, Streptogramin B pharmacology, DNA Topoisomerase IV genetics, Drug Resistance, Multiple, Bacterial genetics, Gene Expression Regulation, Bacterial, Methicillin-Resistant Staphylococcus aureus genetics, Methionine Sulfoxide Reductases genetics, Methyltransferases genetics
- Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) carrying SCCmec type IV has emerged in hospitals worldwide. The aim of this study was to evaluate phenotypic and molecular characteristics of antimicrobial resistance in MRSA SCCmec IV isolates, presenting different genetic backgrounds, isolated from hospitals in Rio de Janeiro. The antimicrobial resistance of 128 S. aureus type IV isolates from 11 hospitals was characterized by the disk diffusion test and minimum inhibitory concentration (MIC) test. Mutations in parC gene, which encodes ciprofloxacin resistance, and genes associated with macrolide-lincosamide-streptogramin B (MLS
b ) resistance were also investigated. MRSA isolates belonging to USA400/ST1 (60 isolates), USA800/ST5 (40), USA1100/ST30 (13), and other 11 (15) lineages were mainly resistant to erythromycin (68%), ciprofloxacin (56%), and clindamycin (50%). The highest antimicrobial resistance rates were found among USA400 isolates (p < 0.05). The majority of them (90%) carried only the erm(C) gene and mainly presented two mutation types in the parC gene. The msr(A) gene was most frequently found among USA800 isolates (p < 0.05). Among MRSA type IV isolates from Rio de Janeiro hospitals, multiresistance, including mutations in parC gene, was associated to the USA400/ST1, while the msr(A) gene was associated with USA800/ST5 isolates, highlighting that these lineages could have more potential to persist in a hospital environment.- Published
- 2016
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