Kobayashi Takehito, Nakaminami Hidemasa, Ohtani Hiroshi, Yamada Kanako, Nasu Yutaka, Takadama Shunsuke, Noguchi Norihisa, Fujii Takeshi, Matsumoto Tetsuya
Department of Infection Prevention and Control, Tokyo Medical University Hospital, 6-7-1 Nishishinjuku, Shinjuku-ku, Tokyo 160-0023, Japan; Department of Microbiology, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo 160-8402, Japan.
Department of Microbiology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan.
J Infect Chemother. 2020 Jan;26(1):76-81. doi: 10.1016/j.jiac.2019.07.009. Epub 2019 Jul 30.
The USA300 clone, which produces Panton-Valentine leukocidin (PVL), is a major highly pathogenic community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) clone that is spreading throughout the world. Although the prevalence of the USA300 clone in Japan was very limited a decade ago, its incidence has been increasing in both community and hospital settings in recent years. There is great concern that the USA300 clone will cause more complicated diseases and become a serious threat to immunocompromised patients in hospital settings. Here, we report an outbreak of severe infectious diseases in a tertiary care university hospital involving the incidence of deep infections, including bacteremia, and continuous and frequent isolation of MRSA strains for five months from six patients and a healthy nursing staff member in the same ward. The genotype of all MRSA isolates was identical to that of the USA300 clone. Furthermore, pulsed-field gel electrophoresis analysis indicated that all MRSA had the same patterns. These data demonstrate that a USA300 clone outbreak had occurred in the hospital. Fortunately, this outbreak was terminated subsequent to the interventions of the infection control team and all patients recovered following the appropriate therapies. Our report demonstrates that patients carrying highly pathogenic CA-MRSA have the potential to become a source of nosocomial outbreaks that can spread to healthy healthcare workers. Therefore, stricter standard precautions should be applied for all patients at the time of admission to prevent such nosocomial outbreaks.
产生杀白细胞素（PVL）的USA300克隆株是一种主要的高致病性社区获得性耐甲氧西林金黄色葡萄球菌（CA-MRSA）克隆株，正在全球范围内传播。尽管十年前USA300克隆株在日本的流行率非常有限，但近年来其在社区和医院环境中的发病率一直在上升。人们非常担心USA300克隆株会引发更复杂的疾病，并对医院环境中的免疫功能低下患者构成严重威胁。在此，我们报告了一家三级护理大学医院发生的严重传染病暴发，涉及深部感染（包括菌血症）的发生率，以及在五个月内从同一病房的六名患者和一名健康护理人员中持续频繁分离出耐甲氧西林金黄色葡萄球菌菌株。所有耐甲氧西林金黄色葡萄球菌分离株的基因型与USA300克隆株相同。此外，脉冲场凝胶电泳分析表明所有耐甲氧西林金黄色葡萄球菌具有相同的图谱。这些数据表明该医院发生了USA300克隆株暴发。幸运的是，在感染控制团队的干预后，此次暴发得以终止，所有患者在接受适当治疗后康复。我们的报告表明，携带高致病性CA-MRSA的患者有可能成为医院感染暴发的源头，并可能传播给健康的医护人员。因此，在所有患者入院时应采取更严格的标准预防措施以防止此类医院感染暴发。
