Molecular Characterization of Community-Associated Methicillin-Resistant and Methicillin-SusceptibleStaphylococcus aureusIsolates from Children with Skin Infections in Busan, Korea

Abstract

The prevalence and molecular characteristics of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) and methicillin-susceptible S. aureus (CA-MSSA) from children with skin infection were investigated by staphylocoagulase (SC) typing, multilocus sequence typing (MLST), SCCmec typing and virulent toxins, including Panton-Valentine leucocidin (PVL), and exfoliative toxins (ET). Among 69 cases of CA-S. aureus for a 3 month period from March to June, 2014 at hospital in Busan, 28 (40.6%) were MRSA and 41 (59.4%) were MSSA. Of the 28 CA-MRSA isolates, two major clones were identified as SC type Vb-ST72-SCCmec type IV (53.6%) and SC type l-ST89-SCCmec type II variant (42.8%), and the remaining one (3.6%) was SC type lll-ST8-SCCmec type IV. In CA-MSSA, the prevalent clone was SC type Vb-ST72 (29.3%), followed by SC type Vb-ST188 (21.9%), SC type Va-ST121 (19.5%) and SC type lV-ST30 (9.6%). None was positive for PVL gene, and all of the SC type l-ST89-SCCmec type II variant clones were ETB gene positive. The data suggest that there are significant clonal relatedness with specific SC types, and genetic diversities in both community strains isolated from children with skin infections.