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.
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.
Afset
Jan Egil
JE
Department of Microbiology, School of Medicine, Norwegian University of Science and Technology, Trondheim, Norway. jan.afset@rit.no
Maeland
Johan A
JA
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*
D000900:Anti-Bacterial Agents; D001414:Bacitracin; D005672:Fusidic Acid; D016712:Mupirocin