title: Clonal dissemination of meticillin-resistant and vancomycin-intermediate Staphylococcus aureus in a Taiwanese hospital.
abstract: Meticillin-resistant and vancomycin-intermediate Staphylococcus aureus (VISA) has emerged worldwide. However, clonal dissemination of VISA in hospitals has rarely been reported. We investigated 43 isolates of meticillin-resistant VISA [vancomycin minimum inhibitory concentrations (MICs) of 4 microg/mL in 35 isolates and 8 microg/mL in 8 isolates) recovered from 21 hospitalised patients. A glycopeptide was given prior to isolation of VISA in 14 of the patients. Five patients (23.8%) died despite vancomycin therapy. All isolates were inhibited by tigecycline at 0.5 microg/mL, linezolid at 1 microg/mL and ceftobiprole at 2 microg/mL. Five isolates (11.6%) had reduced susceptibility to daptomycin (MICs of 1-2 microg/mL). In addition, 6 of the 43 VISA isolates had decreased susceptibility to autolysis by 0.05% Triton X-100. All 43 VISA isolates carried staphylococcal chromosome cassette mec (SCCmec) type III and accessory gene regulator (agr) group I but none carried the Panton-Valentine leukocidin gene (lukS-lukF). None of the enterococcal van genes were detected in the 43 VISA isolates. Molecular typing generated by pulsed-field gel electrophoresis revealed that all isolates belonged to one pulsotype, indicating clonal dissemination of VISA isolates in the hospital. The high rate of non-susceptibility to daptomycin amongst these VISA isolates is alarming and indicates the limitation of this agent for the treatment of infections due to VISA.
authors.affiliation: Departments of Laboratory Medicine and Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Po-Ren
authors.initials: PR
authors.lastname: Hsueh
authors.forename: Shih-Yi
authors.initials: SY
authors.lastname: Lee
authors.forename: Cherng-Lih
authors.initials: CL
authors.lastname: Perng
authors.forename: Tein-Yao
authors.initials: TY
authors.lastname: Chang
authors.forename: Jang-Jih
authors.initials: JJ
authors.lastname: Lu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D005260:Female; D006785:Hospitals, University; D006801:Humans; D008297:Male; D008712:Methicillin / Q000494:pharmacology; D016106:Methicillin Resistance / Q000235:genetics*; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D017720:Molecular Epidemiology; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000235:genetics*; D013624:Taiwan / Q000453:epidemiology; D014640:Vancomycin / Q000494:pharmacology; D020713:Vancomycin Resistance / Q000235:genetics*; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D014640:Vancomycin; D008712:Methicillin