2319. Molecular Epidemiology of Staphyloccoccus aureus Isolated From Korean Children

BACKGROUND: Major community acquired-methicillin-resistant Staphylococcus aureus (CA-MRSA) clones have been reported worldwide including ST1 in Asia, Europe, United States, ST8 in Europe and United States and ST30 in Australia, Europe and South America. Panton–Valentine leukocidin (PVL) positive ST30-SCCmec IV has been reported as an important CA-MRSA in Singapore, Japan and Latin America, however reports in Korean children are limited. Therefore we investigated the antimicrobial resistance and molecular characteristics of S. aureus among children in Korea. METHODS: S. aureus previously isolated from children at Seoul National University Bundang Hospital (2010–2016) were analyzed for multilocus sequence type, SCCmec typing, and PCR of PVL, qac A/B, smr and mupA genes. Electronic medical records were reviewed for clinical data and antibiotic susceptibility results. RESULTS: A total of 79 isolates from skin and soft-tissue infection (SSTI) (N = 41, 51.9%), bone and joint infection (N = 26, 32.9%) and staphylococcal scalded skin syndrome (SSSS) (N = 12, 15.2%) were included. Among these, 32 (40.5%) were MRSA. Among children with underlying diseases (20.3%, 16/79), 56.3% (9/16) were MRSA. After excluding these cases, among children ≤1 month of age, 84.6% (11/13) were MRSA, whereas in children ≥2 months of age, 95.2% (20/21) of SSTI, and 90.0% (18/20) of bone and joint infection were MSSA. All SSSS cases were MRSA. Among MSSA strains, ST30 (N = 28, 59.6%) was the predominant clone and among ST30, 96.6% (28/29) were MSSA. MRSA strains included ST72-SCCmec IV (N = 15, 46.9%), ST89-SCCmec IV (N = 10, 31.3%), ST 5-SCCmec II (N = 3, 9.4%) and ST1-SCCmec IV (N = 3, 9.4%). ST30 was the most common clone in SSTI and bone and joint infection whereas ST89-SCCmec IV was most common in SSSS. PVL was detected in 3 strains (3.8%, ST30-SCCmec IV N = 1, MSSA ST30 N = 2) and qac A/B in 3 strains (MRSA = 3), smr in 3 strains (MSSA = 1, MRSA=2) and mupA in 7 strains (MRSA = 5, MSSA = 2). CONCLUSION: The molecular epidemiology of S. aureus in Korean children differed from other countries. Among children with SSTI and bone and joint infection, ST30 was the predominant strain, and the majority was MSSA. Among MRSA isolates, ST72-SCCmec type IV was the most common clone in SSTI and bone and joint infection, and ST89-SCCmec type IV in SSSS. DISCLOSURES: H. Lee, National Research Foundation of Korea: Grant Investigator, Grant recipient