In the present study, 26 Staphylococcus aureus strains, including 16 methicillin-resistant S. aureus (MRSA) and 10 methicillin-susceptible S. aureus (MSSA), which were collected from eight medical institutions in Chiba Prefecture that requested toxin gene analysis from 2015 to 2021, were analyzed. A total of 14 Panton-Valentine leukocidin (PVL) positive strains were identified, including one of MSSA. PVL-positive strains were classified into seven types based on polymerase chain reaction-based open reading frame typing (POT). Of these, three POT types of MRSA strains were not previously reported, and one had been previously reported as PVL-negative. Some strains were positive for both PVL and toxic shock syndrome toxin 1 (TSST-1). One POT type was identified in both PVL-positive and PVL-negative strains. This is the first report on the regional spread of highly pathogenic S. aureus strains in children from multiple medical institutions based on the POT method. This method is useful for estimating the spread of toxin gene-carrying strains in the community because of its association with toxin genes. As the number of PVL-positive strains is increasing in Japan, it is important to analyze the isolates of severe S. aureus infections in children by combining toxin gene analysis and the POT method.

在本研究中，26株金黄色葡萄球菌菌株，包括16株耐甲氧西林金黄色葡萄球菌（MRSA）和10株甲氧西林敏感金黄色葡萄球菌（MSSA），是从2015年起从千叶县要求进行毒素基因分析的八家医疗机构收集的。到 2021 年，进行了分析。共鉴定出 14 株 Panton-Valentine 杀白细胞素 (PVL) 阳性菌株，其中包括 1 株 MSSA。基于聚合酶链式反应的开放阅读框分型（POT），PVL阳性菌株被分为七种类型。其中，三种 POT 类型的 MRSA 菌株此前未曾报道，其中一种此前曾报道为 PVL 阴性。一些菌株对 PVL 和中毒性休克综合征毒素 1 (TSST-1) 均呈阳性。在 PVL 阳性和 PVL 阴性菌株中均鉴定出一种 POT 类型。这是首次基于POT方法对多个医疗机构儿童高致病性金黄色葡萄球菌菌株的区域传播情况进行报告。由于该方法与毒素基因相关，因此可用于估计社区中携带毒素基因的菌株的传播。随着日本PVL阳性菌株的数量不断增加，结合毒素基因分析和POT方法对儿童严重金黄色葡萄球菌感染的分离株进行分析具有重要意义。