Antimicrobial Resistance and Molecular Analysis of Staphylococcus aureus in Staphylococcal Scalded Skin Syndrome among Children in Korea

BACKGROUND: Staphylococcal scalded skin syndrome (SSSS) is a skin disease characterized by blistering and desquamation caused by exfoliative toxins (ETs) of Staphylococcus aureus (S. aureus). Although many countries show predominance of methicillin-susceptible S. aureus (MSSA), cases of methicillin-resistant S. aureus (MRSA) have been reported. METHODS: Twenty-six children aged <15 years diagnosed with SSSS from January 2010 to December 2017 from three hospitals were included. S. aureus isolates from cases were analyzed for multilocus sequence types and ETs. Medical records were reviewed for clinical characteristics, treatment, and antimicrobial susceptibility patterns of S. aureus. RESULTS: Among the 26 cases, mean age was 2.3 years. According to skin manifestations patients were classified as generalized (n = 10, 38.5%), intermediate (n = 11, 42.3%), and abortive (n = 5, 19.2%). Among all cases, 96.2% (25/26) were due to MRSA and the macrolide-resistance rate was 92.3% (24/26). ST89 (n = 21, 80.8%) was the most prevalent clone, followed by single clones of ST1, ST5, ST72, ST121, and ST1507. The eta gene was detected in one (3.8%) isolate which was MSSA. The etb gene was detected in 14 (53.8%) isolates, all of which were ST89. Nafcillin or first-generation cephalosporin was most commonly prescribed (n=20, 76.9%). Vancomycin was administered in four patients (15.4%) and clindamycin in nine patients (34.6%). Among MRSA cases, there was no difference in duration of treatment when comparing the use of antimicrobials to which the causative bacteria were susceptible or non-susceptible (9.75 vs. 8.07 days, P > 0.05). CONCLUSION: S. aureus isolated from children with SSSS in Korea demonstrated a high prevalence of methicillin-resistant ST89 clones that harbored the etb gene. The predominance of MRSA suggests that antibiotics to which MRSA are susceptible may be considered for empirical antibiotic treatment in children with SSSS in Korea. Further studies on the role and effectiveness of systemic antibiotics in SSSS are warranted.