Importance of colonization site in the current epidemic of staphylococcal skin abscesses

Abstract

Objective: The goal was to compare rectal and nasal Staphylococcus aureus colonization rates and S aureus pulsed-field types (PFTs) for children with S aureus skin and soft-tissue abscesses and normal control subjects.

Methods: Sixty consecutive children with S aureus skin and soft-tissue abscesses that required surgical drainage and 90 control subjects were enrolled. Cultures of the nares and rectum were taken in both groups. S aureus isolates from all sites were characterized through multiple-locus, variable-number, tandem-repeat analysis, pulsed-field gel electrophoresis, staphylococcal cassette chromosome mec typing for methicillin-resistant S aureus isolates, and determination of the presence of Panton-Valentine leukocidin genes.

Results: S aureus was detected significantly more often in the rectum of children with abscesses (47%) compared with those in the control group (1%; P = .0001). Rates of nasal colonization with S aureus were equivalent for children with abscesses (27%) and control subjects (20%; P = .33). S aureus recovered from the rectum was identical to S aureus in the abscess in 88% of cases, compared with 75% of nasal isolates. PFT USA300, staphylococcal cassette chromosome mec type IV, and Panton-Valentine leukocidin genes were significantly increased in the S aureus isolates from children with abscesses compared with those from control subjects.

Conclusions: Skin and soft-tissue abscesses in the current epidemic of community-associated staphylococcal disease are strongly associated with rectal colonization by PFT USA300. Nasal colonization in children does not seem to be a risk factor.