title: Susceptibility of skin and soft-tissue isolates of Staphylococcus aureus and Streptococcus pyogenes to topical antibiotics: indications of clonal spread of fusidic acid-resistant Staphylococcus aureus.
abstract: Staphylococcus aureus (SA) isolates (n = 255) from outpatients with skin and soft-tissue infections were collected in 3 different areas in Norway. Group A streptococci (GAS, n = 68) were isolated from skin or pharyngotonsillar specimens from outpatients. Minimum inhibitory concentrations (MIC) of bacitracin, fusidic acid and mupirocin were tested using the E-test. Pulsed field gel electrophoresis (PFGE) patterns of fusidic acid-sensitive (FusS) and -resistant (FusR) SA were compared. All GAS isolates showed MIC of bacitracin of < or = 1.0 mg/l, of mupirocin of < or = 0.125 mg/l and of fusidic acid 1.0-4.0 mg/l. All the SA showed MIC of mupirocin < or = 0.5 mg/l and of bacitracin of > or = 2.0 mg/l, 91% with MIC > or = 16 mg/l. FusR was shown by 32.5% of the SA strains with similar prevalence rates in 3 different geographical areas of Norway. One particular PFGE pattern (type 1) was shown by 76% of the FusR SA. SA of type 1 belonged to phage group II and produced exfoliative toxins. Thus, the results demonstrated a high prevalence of FusR among SA causing skin infections and that this was mainly due to dissemination of clonally related FusR SA.
authors.affiliation: Department of Microbiology, School of Medicine, Norwegian University of Science and Technology, Trondheim, Norway. jan.afset@rit.no
authors.forename: Jan Egil
authors.initials: JE
authors.lastname: Afset
authors.forename: Johan A
authors.initials: JA
authors.lastname: Maeland
mesh_terms: D000287:Administration, Topical; D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D001414:Bacitracin / Q000494:pharmacology; D002648:Child; D024881:Drug Resistance, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D005672:Fusidic Acid / Q000494:pharmacology*; D005798:Genes, Bacterial; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D016712:Mupirocin / Q000494:pharmacology; D011336:Probability; D012680:Sensitivity and Specificity; D017192:Skin Diseases, Bacterial / Q000188:drug therapy / Q000382:microbiology; D018461:Soft Tissue Infections / Q000188:drug therapy / Q000382:microbiology; D013203:Staphylococcal Infections / Q000188:drug therapy; D013211:Staphylococcus aureus / Q000187:drug effects / Q000235:genetics*; D013290:Streptococcal Infections / Q000188:drug therapy; D013297:Streptococcus pyogenes / Q000187:drug effects / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D001414:Bacitracin; D005672:Fusidic Acid; D016712:Mupirocin