Kang Sunghan, Lee Jina, Kim Mina
Department of Pediatrics Department of Laboratory Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
Medicine (Baltimore). 2017 Aug;96(34):e7838. doi: 10.1097/MD.0000000000007838.
This study was performed to investigate the concordance in terms of molecular characteristics and antimicrobial susceptibility between colonizing and clinical Staphylococcus aureus isolates obtained from children in Korea, where ST72 is the major genotype.This was a prospective observational descriptive study of culture-confirmed S aureus infections obtained from children ≤18 years old admitted to Asan Medical Center Children's Hospital in Seoul, Korea, from March 2014 to April 2015. Molecular studies including multilocus sequence typing (MLST), SCCmec typing, polymerase chain reaction amplification of the Panton-Valentine leukocidin (PVL) genes, and antibiotic susceptibility tests were performed on S aureus isolates obtained from nares and clinical specimens.During the study period, 126 clinically significant S aureus infections were identified. Nasal swab cultures were made from 113 of the 126 children, and 46.0% (52/113) showed S aureus colonization. The overall concordance between colonizing and clinical isolates by methicillin susceptibility was 94.2% (49/52); all 3 discordant cases were HA-MSSA cases with nasal MRSA. Among the 37 pairs of colonizing and clinical S aureus isolates included in the genotyping analysis, ST72-SCCmec type IV was the most prevalent clone and the PVL genes were positive in 2 patients. Among the 31 pairs of healthcare-associated cases, concordance rates by methicillin susceptibility and sequence type (ST) were 90.3% (28/31) and 84% (26/31), respectively. For the 6 pairs of community-associated (CA) S aureus including 3 CA-MRSA cases, 100% concordance was observed by methicillin susceptibility and ST.The concordance between isolates obtained from children who required medical services was relatively high in Korean children where ST72-SCCmec type IV is the predominant clone as the colonizer and the pathogen. It is suggested that decolonization and continuous care to prevent transmission could be effective in managing and preventing both HA- and CA-SA infections in our setting.
本研究旨在调查在韩国儿童中分离出的定植金黄色葡萄球菌与临床金黄色葡萄球菌在分子特征和抗菌药物敏感性方面的一致性，在韩国ST72是主要基因型。这是一项对2014年3月至2015年4月在韩国首尔峨山医疗中心儿童医院住院的18岁及以下儿童确诊的金黄色葡萄球菌感染进行的前瞻性观察性描述性研究。对从鼻腔和临床标本中分离出的金黄色葡萄球菌进行了包括多位点序列分型（MLST）、SCCmec分型、杀白细胞素（PVL）基因的聚合酶链反应扩增以及抗生素敏感性测试在内的分子研究。在研究期间，共鉴定出126例具有临床意义的金黄色葡萄球菌感染。对126名儿童中的113名进行了鼻拭子培养，46.0%（52/113）显示有金黄色葡萄球菌定植。定植菌株与临床分离株之间甲氧西林敏感性的总体一致性为94.2%（49/52）；所有3例不一致的病例均为鼻腔MRSA的HA-MSSA病例。在基因分型分析中纳入的37对定植和临床金黄色葡萄球菌分离株中，ST72-SCCmec IV型是最常见的克隆型，2例患者的PVL基因呈阳性。在31对医疗保健相关病例中，甲氧西林敏感性和序列类型（ST）的一致性率分别为90.3%（28/31）和84%（26/31）。对于6对社区相关（CA）金黄色葡萄球菌，包括3例CA-MRSA病例，甲氧西林敏感性和ST的一致性为100%。在以ST72-SCCmec IV型作为主要定植菌和病原菌的韩国儿童中，从需要医疗服务的儿童中分离出的菌株之间的一致性相对较高。建议去定植和持续护理以防止传播在我们的环境中对管理和预防HA-和CA-SA感染可能是有效的。
