title: Differences in clinical and molecular characteristics of skin and soft tissue methicillin-resistant Staphylococcus aureus isolates between two hospitals in Northern California.
abstract: Community-onset methicillin-resistant Staphylococcus aureus (CO-MRSA) skin and soft tissue infections (SSTI) are associated with SCCmec IV and Panton-Valentine leukocidin (PVL) genes. CO-MRSA epidemiologic studies suggest that genotypic variation exists within one geographic region. We compared MRSA genotypes and demographic and clinical characteristics of patients with CO-MRSA SSTI between two regional medical centers. We also examined factors associated with SCCmec IV and PVL carriage. A total of 279 MRSA SSTI isolates from 2000 to 2002 at San Francisco General Hospital (SFGH) and Stanford University Hospital (SUH) were genotyped by pulsed-field gel electrophoresis and PCR for SCCmec and PVL genes. Medical records were reviewed for clinical characteristics. Ninety-three percent and 69% of MRSA SSTI were caused by CO-MRSA at SFGH and SUH, respectively. Patients with CO-MRSA SSTI at SFGH were more likely to be nonwhite, younger, homeless, and have no previous exposure to health care (P < 0.01). SFGH CO-MRSA strains were more likely to carry SCCmec type IV and PVL genes (90% and 55%, respectively) than SUH strains (29% and 16%, respectively). In multivariate analyses, nonwhite ethnicity was associated with both SCCmec type IV and PVL carriage (odds ratio [OR] of 2.65 and 95% confidence interval [CI] of 1.19 to 5.95 and OR of 1.94 and 95% CI of 1.03 to 3.65, respectively). ST8:USA300:IV became the dominant clone at SFGH, but not at SUH, by 2002. Despite geographic proximity, CO-MRSA SSTI exhibited differing SCCmec types, PVL carriage, and clonal dynamics. CO-MRSA SSTI at SUH were more likely to represent feral isolates of nosocomial origin. Clinicians should assess for nosocomial and community risk factors, realizing that different populations with CO-MRSA SSTI may require separate antimicrobial strategies.
authors.affiliation: Stanford University, Stanford, California, USA.
authors.forename: Debika
authors.initials: D
authors.lastname: Bhattacharya
authors.forename: Heather
authors.initials: H
authors.lastname: Carleton
authors.forename: Chiaojung J
authors.initials: CJ
authors.lastname: Tsai
authors.forename: Ellen Jo
authors.initials: EJ
authors.lastname: Baron
authors.forename: Françoise
authors.initials: F
authors.lastname: Perdreau-Remington
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002140:California / Q000453:epidemiology; D017714:Community-Acquired Infections / Q000453:epidemiology / Q000382:microbiology / Q000503:physiopathology; D005260:Female; D006761:Hospitals; D006786:Hospitals, Urban; D006801:Humans; D008297:Male; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D015995:Prevalence; D018461:Soft Tissue Infections / Q000453:epidemiology / Q000382:microbiology / Q000503:physiopathology; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology / Q000503:physiopathology; D013207:Staphylococcal Skin Infections / Q000453:epidemiology / Q000382:microbiology / Q000503:physiopathology; D013211:Staphylococcus aureus / Q000145:classification* / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification; D013383:Suburban Population
chemical_list: D000900:Anti-Bacterial Agents