Epidemiological study of Staphylococcus aureus resistant to methicillin responsible for nosocomial infections in nine French hospitals.
A number of European studies found that nosocomial infections were caused by a limited number of methicillin-resistant Staphylococcus aureus (MRSA) strains. A study was undertaken to determine the number of MRSA clones responsible for nosocomial infections in France. Strains responsible for nosocomial infections meeting CDC criteria were collected one week every month from June to October 1997 in nine French hospitals. Strains that were positive by the oxacillin-resistance screening test were studied for the IS 431, femA, and mecA genes. Strain type was identified using pulsed-field gel electrophoresis of fragments produced by Smal digestion. Susceptibility to antimicrobials was evaluated based on inhibition zone diameters and minimal inhibitory concentrations determined using the agar dilution method. The 83 strains studied were distributed across four pulsotypes. Eleven resistance phenotypes were identified by ascending hierarchical classification based on inhibition zone diameters. MRSAs responsible for nosocomial infections belong to a limited number of clones that express variable levels of resistance to antimicrobials.
Service de Microbiologie, Centre Hospitalier de Versailles, Le Chesnay, France.
B
B
Pangon
P
P
Pina
T
T
Godard
P
P
Allouch
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology; D003710:Demography; D016521:Electrophoresis, Gel, Pulsed-Field; D005602:France / Q000453:epidemiology; D006801:Humans; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests / Q000379:methods; D010068:Oxacillin / Q000494:pharmacology; D010641:Phenotype; D013203:Staphylococcal Infections / Q000453:epidemiology*; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification
D000900:Anti-Bacterial Agents; D010068:Oxacillin