1. Staphylococcus aureus Colonization and Strain Type at Various Body Sites among Patients with a Closed Abscess and Uninfected Controls at U.S. Emergency Departments.
- Author
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Albrecht VS, Limbago BM, Moran GJ, Krishnadasan A, Gorwitz RJ, McDougal LK, and Talan DA
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Carrier State, Community-Acquired Infections microbiology, Comorbidity, Emergency Service, Hospital, Female, Humans, Male, Methicillin-Resistant Staphylococcus aureus classification, Methicillin-Resistant Staphylococcus aureus pathogenicity, Middle Aged, Skin microbiology, Soft Tissue Infections microbiology, Surveys and Questionnaires, United States, Young Adult, Abscess microbiology, Groin microbiology, Methicillin-Resistant Staphylococcus aureus isolation & purification, Nasal Cavity microbiology, Pharynx microbiology, Staphylococcal Skin Infections microbiology
- Abstract
Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is a prevalent cause of skin and soft tissue infections (SSTI), but the association between CA-MRSA colonization and infection remains uncertain. We studied the carriage frequency at several body sites and the diversity of S. aureus strains from patients with and without SSTI. Specimens from the nares, throat, rectum, and groin of case subjects with a closed skin abscess (i.e., without drainage) and matched control subjects without a skin infection (n = 147 each) presenting to 10 U.S. emergency departments were cultured using broth enrichment; wound specimens were cultured from abscess cases. Methicillin resistance testing and spa typing were performed for all S. aureus isolates. S. aureus was found in 85/147 (57.8%) of abscesses; 49 isolates were MRSA, and 36 were methicillin-susceptible S. aureus (MSSA). MRSA colonization was more common among cases (59/147; 40.1%) than among controls (27/147; 18.4%) overall (P < 0.001) and at each body site; no differences were observed for MSSA. S. aureus-infected subjects were usually (75/85) colonized with the infecting strain; among MRSA-infected subjects, this was most common in the groin. The CC8 lineage accounted for most of both infecting and colonizing isolates, although more than 16 distinct strains were identified. Nearly all MRSA infections were inferred to be USA300. There was more diversity among colonizing than infecting isolates and among those isolated from controls versus cases. CC8 S. aureus is a common colonizer of persons with and without skin infections. Detection of S. aureus colonization, and especially MRSA, may be enhanced by extranasal site culture., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)
- Published
- 2015
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