Hayakawa Katsura, Yamaguchi Tetsuo, Ono Daisuke, Suzuki Hajime, Kamiyama Jiro, Taguchi Shigemasa, Kiyota Kazuya
Department of Emergency and Critical Care Medicine, Saitama Red Cross Hospital, Saitama, Japan.
Department of Microbiology and Infection Diseases, Toho University School of Medicine, Tokyo, Japan.
Infect Drug Resist. 2020 Aug 20;13:2921-2927. doi: 10.2147/IDR.S262123. eCollection 2020.
produces numerous toxins, such as toxic shock syndrome toxin 1 (TSST-1) and Panton-Valentine leukocidin (PVL). We isolated community-acquired methicillin-resistant (CA-MRSA) strains producing both TSST-1 and PVL isolated from severe necrotizing pneumonia cases in a Nepali family. Detection of these CA-MRSA strains is rare in the world, and infection with these strains can take a rapidly progressive and lethal course. In this study, we traced the clinical course of this case and conducted a genetic analysis of the isolated strains.
We described 2 familial cases (a 20-year-old male and 61-year-old female) of severe necrotizing pneumonia caused by CA-MRSA with the TSST-1 and PVL genes. A 20-year-old Nepalese male was admitted to our hospital after a 3-day history of high fever and coughing. Despite resuscitation efforts, he died of multiple organ failure. A 61-year-old Nepalese female was admitted to our hospital with a complaint of high fever and dyspnea for 1 day. She was the grandmother of the male subject and mostly stayed at his residence in Japan. We administered intravenous antibiotics, including anti-MRSA antibiotics, and she improved in 2 weeks. The sequence type of the isolates was ST22/SCCmec type IVa, and the spa type was t005. The virulence genes detected were as follows: PVL gene (lukSF-pv), TSST-1 gene (tst-1), sec, seg, sei, sel, sem, sen, seo, and seu. ST22 was not the dominant CA-MRSA clone type in Japan. Some of the reports demonstrated that PVL-/TSST-1-positive ST22-MRSA strains are prevalent in Nepal. Therefore, the MRSA strains were thought to be acquired from Nepal.
These cases highlight the emergence of TSST-1- and PVL-positive CA-MRSA infection and its association with life-threatening community-acquired necrotizing pneumonia. Clinicians should note the possibility of introducing MRSA strains from abroad and be aware of this illness to initiate appropriate treatment.
可产生多种毒素，如中毒性休克综合征毒素1（TSST-1）和杀白细胞素（PVL）。我们从尼泊尔一个家庭的严重坏死性肺炎病例中分离出了同时产生TSST-1和PVL的社区获得性耐甲氧西林金黄色葡萄球菌（CA-MRSA）菌株。在世界范围内，检测到这些CA-MRSA菌株的情况很少见，感染这些菌株可能会导致病情迅速进展并致命。在本研究中，我们追踪了该病例的临床病程，并对分离出的菌株进行了基因分析。
我们描述了2例由携带TSST-1和PVL基因的CA-MRSA引起的严重坏死性肺炎家族病例（一名20岁男性和一名61岁女性）。一名20岁的尼泊尔男性在出现3天高热和咳嗽病史后入住我院。尽管进行了复苏努力，但他死于多器官功能衰竭。一名61岁的尼泊尔女性因高热和呼吸困难1天入住我院。她是男性患者的祖母，大部分时间待在日本他的住所。我们给予了包括抗MRSA抗生素在内的静脉抗生素治疗，她在2周内病情好转。分离菌株的序列类型为ST22/SCCmec IVa型，spa类型为t005。检测到的毒力基因如下：PVL基因（lukSF-pv）、TSST-1基因（tst-1）、sec、seg、sei、sel、sem、sen、seo和seu。ST22不是日本CA-MRSA的主要克隆类型。一些报告表明，PVL-/TSST-1阳性的ST22-MRSA菌株在尼泊尔很普遍。因此，这些MRSA菌株被认为是从尼泊尔获得的。
这些病例凸显了TSST-1和PVL阳性CA-MRSA感染的出现及其与危及生命的社区获得性坏死性肺炎的关联。临床医生应注意从国外引入MRSA菌株的可能性，并了解这种疾病以便启动适当的治疗。
