Nakaminami Hidemasa, Noguchi Norihisa, Ito Ayumu, Ikeda Masashi, Utsumi Kenta, Maruyama Hiroshi, Sakamoto Haruo, Senoo Masako, Takasato Yoshio, Nishinarita Susumu
Department of Microbiology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, 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. 2014 Aug;20(8):512-5. doi: 10.1016/j.jiac.2014.03.006. Epub 2014 Apr 21.
The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) remains problematic in both hospital and community settings. Investigations of MRSA existing in the local area are necessary to understand the detailed epidemiology of healthcare-associated MRSA (HA-MRSA). In the present study, molecular epidemiological analysis was performed on 584 MRSA isolated from four hospitals in Tokyo, Japan. In the pulsed-field gel electrophoresis (PFGE) analysis, four epidemic pulsotypes (I to IV) were found. The isolates of the epidemic pulsotype I mainly consisted of the SCCmec type II, toxic shock syndrome toxin 1 gene (tst)-negative, spa type t002, and ST764 clones. The ST764 clone, which is a novel hybrid variant of the ST5 HA-MRSA lineage with the arginine catabolic mobile element (ACME), was first found in Niigata, Japan. However, no ACME genes were detected in the isolates of the epidemic pulsotype I. In contrast, the other isolates of the epidemic pulsotypes mainly consisted of the SCCmec type II, tst-positive, spa type t002, and ST5 clones, which are the most predominant clones of HA-MRSA in Japan. Resistance rates of non-β-lactams for the isolates of the epidemic pulsotype I were higher than those of the other epidemic pulsotypes. Our data showed that the novel ACME-negative ST764 clones are being distributed throughout multiple hospitals in Tokyo. The ST764 clones in Tokyo have the potential to acquire ACME in the future, because the ACME-positive ST764 clones have already been found in both hospital and community settings in other areas of Japan.
耐甲氧西林金黄色葡萄球菌（MRSA）在医院和社区环境中的流行率仍然是个问题。有必要对当地存在的MRSA进行调查，以了解医疗保健相关MRSA（HA-MRSA）的详细流行病学情况。在本研究中，对从日本东京四家医院分离出的584株MRSA进行了分子流行病学分析。在脉冲场凝胶电泳（PFGE）分析中，发现了四种流行脉冲型（I至IV）。流行脉冲型I的分离株主要由SCCmec II型、中毒性休克综合征毒素1基因（tst）阴性、spa型t002和ST764克隆组成。ST764克隆是ST5 HA-MRSA谱系与精氨酸分解代谢移动元件（ACME）的新型杂交变体，首次在日本新泻发现。然而，在流行脉冲型I的分离株中未检测到ACME基因。相比之下，其他流行脉冲型的分离株主要由SCCmec II型、tst阳性、spa型t002和ST5克隆组成，这些是日本HA-MRSA最主要的克隆。流行脉冲型I分离株的非β-内酰胺类耐药率高于其他流行脉冲型。我们的数据表明，新型ACME阴性的ST764克隆正在东京的多家医院中传播。东京的ST764克隆未来有可能获得ACME，因为在日本其他地区的医院和社区环境中已经发现了ACME阳性的ST764克隆。
