Survey, characterization and susceptibility to fusidic acid of Staphylococcus aureus in the Carmarthen area.

OBJECTIVE This retrospective study was designed to investigate the possible reasons for an apparent increase in fusidic acid resistance among Staphylococcus aureus. MATERIALS AND METHODS The Datastore records of the Communicable Disease Surveillance Centre, Wales, UK were reviewed in conjunction with information concerning the prescribing of fusidic acid. RESULTS During the 5 year study period (1997-2001), a rise in the incidence of fusidic acid resistance was noted, particularly among paediatric patients presenting with infected eczema and impetigo, which may be related to the observed increase in prescriptions of topical fusidic acid. Extended phenotypic and genotypic characterization of a limited number (n=31) of isolates from 2002 showed that fusidic acid-resistant strains of S. aureus were typically from patients with impetigo and isolates fell into a single clonal group. Conversely, isolates from other skin disease (eczema, dermatitis and abscesses) were usually susceptible to fusidic acid and proved a diverse group. CONCLUSION This study provides valuable data on the prevalence of fusidic acid-resistant S. aureus, the genetic background of the strains, and their association with clinical disease in both the healthcare environment and community setting in the catchment area served by the Laboratory.