Yamamoto Tatsuo, Dohmae Soshi, Saito Kohei, Otsuka Taketo, Takano Tomomi, Chiba Megumi, Fujikawa Katsuko, Tanaka Mayumi
Division of Bacteriology, Department of Infectious Disease Control and International Medicine, Niigata University Graduate School of Medical and Dental Sciences, 757 Ichibanchou, Asahimachidori, Niigata 951-8510, Japan.
Antimicrob Agents Chemother. 2006 Dec;50(12):4077-86. doi: 10.1128/AAC.00847-06. Epub 2006 Oct 16.
Highly virulent, community-acquired methicillin-resistant Staphylococcus aureus (MRSA) strains with Panton-Valentine leucocidin (PVL) genes have been found increasingly worldwide. Among a total of 2,101 MRSA strains isolated from patients in hospitals in Japan, two were positive for PVL genes. One strain was identified as a community-acquired MRSA strain with genotype sequence type 30 (ST30) and spa (staphylococcal protein A gene) type 19 from Japan and was resistant only to beta-lactam antimicrobial agents. The other strain was closely related to PVL+ multidrug-resistant, hospital-acquired MRSA strains (ST30, spa type 43) derived from nosocomial outbreaks in the 1980s to 1990s in Japan but with a divergent sequence type, ST765 (a single-locus variant of ST30). Twenty-two PVL+ MRSA strains, including those from Japan and those from other countries with various sequence types (ST1, ST8, ST30, ST59, and ST80) and genotypes, were examined for susceptibility to 31 antimicrobial agents. Among the agents, DX-619, a des-fluoro(6) quinolone, showed the greatest activity, followed by rifampin and sitafloxacin, a fluoroquinolone. The data suggest that DX-619 exhibits a superior activity against PVL+ MRSA strains with various virulence genetic traits from the community as well as from hospitals.
在全球范围内，携带杀白细胞素（PVL）基因的高毒力社区获得性耐甲氧西林金黄色葡萄球菌（MRSA）菌株的发现越来越多。在从日本医院患者中分离出的总共2101株MRSA菌株中，有2株PVL基因呈阳性。其中一株被鉴定为来自日本的基因型序列类型30（ST30）和葡萄球菌蛋白A基因（spa）类型19的社区获得性MRSA菌株，且仅对β-内酰胺类抗菌药物耐药。另一株与20世纪80年代至90年代日本医院爆发的PVL+多重耐药医院获得性MRSA菌株（ST30，spa类型43）密切相关，但序列类型不同，为ST765（ST30的单一位点变体）。对包括来自日本以及来自其他国家具有各种序列类型（ST1、ST8、ST30、ST59和ST80）和基因型的22株PVL+ MRSA菌株进行了31种抗菌药物的敏感性检测。在这些药物中，去氟（6）喹诺酮类药物DX-619活性最强，其次是利福平和喹诺酮类药物西他沙星。数据表明，DX-619对来自社区以及医院的具有各种毒力遗传特征的PVL+ MRSA菌株表现出优异的活性。
