| Abstract: | Staphylococcus aureus is highly prevalent among patients with atopicdermatitis (AD), and this pathogen may trigger and aggravate AD lesions. The aim ofthis study was to determine the prevalence of S. aureus in the naresof pediatric subjects and verify the phenotypic and molecular characteristics of theisolates in pediatric patients with AD. Isolates were tested for antimicrobialsusceptibility, SCCmectyping, and Panton-Valentine Leukocidin (PVL)genes. Lineages were determined by pulsed-field gel electrophoresis and multilocussequence typing (MLST). AD severity was assessed with the Scoring Atopic Dermatitis(SCORAD) index. Among 106 patients, 90 (85%) presented S. aureusisolates in their nares, and 8 also presented the pathogen in their skin infections.Two patients had two positive lesions, making a total of 10 S.aureusisolates from skin infections. Methicillin-resistant S.aureus(MRSA) was detected in 24 (26.6%) patients, and PVL genes wereidentified in 21 (23.3%), including 6 (75%) of the 8 patients with skin lesions butmainly in patients with severe and moderate SCORAD values (P=0.0095). All 24 MRSAisolates were susceptible to trimethoprim/sulfamethoxazole, while 8 isolates had aminimum inhibitory concentration (MIC) to mupirocin >1024 μg/mL. High lineagediversity was found among the isolates including USA1100/ST30, USA400/ST1,USA800/ST5, ST83, ST188, ST718, ST1635, and ST2791. There was a high prevalence ofMRSA and PVL genes among the isolates recovered in this study. PVL genes were foundmostly among patients with severe and moderate SCORAD values. These findings can helpclinicians improve the therapies and strategies for the management of pediatricpatients with AD. |
