Genetic lineages and antimicrobial resistance genotypes in Staphylococcus aureus from children with atopic dermatitis: detection of clonal complexes CC1, CC97 and CC398.

The objective was to analyse the genetic lineages of Staphylococcus aureus recovered from nasal and skin samples of atopic dermatitis (AD) paediatric patients, and to characterize the antimicrobial resistance phenotype–genotype and the immune-evasion-cluster (IEC) type of isolates. Forty S. aureus isolates from 35 patients (skin: 26; nasal samples: 14) were characterized. Isolates were submitted to spa-, agr- and multilocus sequence typing. All S. aureus strains analyzed were methicillin-susceptible (MSSA). High genetic diversity was detected among the 40 MSSA isolates (especially among skin isolates), with detection of 27 different spa-types, 20 sequence-types and 16 clonal complexes (CCs). Lineages CC30 and CC5 were predominant among nasal isolates (71% vs 23% skin). Thirteen different CCs were detected among skin isolates, with detection of clades CC1, CC9 and CC398. Antimicrobial resistance rates detected were higher in skin than in nasal isolates, especially for macrolides, aminoglycosides, lincosami...