RESUMO
Seventy-one percent of 76 methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from two medical centers in El Paso, Texas, represent three similar pulsed-field gel electrophoresis types. Overall, six pulsed-field types were identified represented by multilocus sequence/staphylococcal chromosomal cassette DNA mec (SCCmec) types: ST5-MRSA-II; ST36-MRSA-II; ST8 (untypeable SCCmec); and a newly described clonal cluster 8 strain, ST507-MRSA-IV. This study demonstrates the presence of multiple-antibiotic-resistant epidemic MRSA clones in El Paso.
Assuntos
Antibacterianos/farmacologia , Hospitais , Resistência a Meticilina , Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus/efeitos dos fármacos , Técnicas de Tipagem Bacteriana , Farmacorresistência Bacteriana Múltipla , Eletroforese em Gel de Campo Pulsado , Humanos , Resistência a Meticilina/genética , Testes de Sensibilidade Microbiana , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/classificação , Staphylococcus aureus/genética , Texas/epidemiologiaRESUMO
The sarA locus of Staphylococccus aureus regulates the synthesis of over 100 genes on the S. aureus chromosome. We now report the effects of sarA inactivation on intrinsic multidrug resistance expression by S. aureus. In a strain-dependent fashion, sarA::kan mutants of three unrelated strains of S. aureus demonstrated significantly increased susceptibility to five or more of the following substances: the antibiotics ciprofloxacin, fusidic acid, and vancomycin; the DNA-intercalating agent ethidium; and four common household cleaner formulations. In addition, all three sarA::kan mutants demonstrated significantly increased accumulation of ciprofloxacin and one sarA::kan mutant demonstrated increased ethidium accumulation. Our data therefore indicate that sarA plays a role in the intrinsic multidrug resistance mechanism expressed by S. aureus, in part by regulating drug accumulation.
