Ikeda-Dantsuji Yurika, Hanaki Hideaki, Sakai Fuminori, Tomono Kazunori, Takesue Yoshio, Honda Junichi, Nonomiya Yuriko, Suwabe Akira, Nagura Osanori, Yanagihara Katsunori, Mikamo Hiroshige, Fukuchi Kunihiko, Kaku Mitsou, Kohno Shigeru, Yanagisawa Chie, Nakae Taiji, Yoshida Koichiro, Niki Yoshihito
Kansenshogaku Zasshi. 2015 Jul;Suppl 13:8-14.
Limited use of linezolid for treating methicillin-resistant Staphylococcus aureus (MRSA) infection was approved in Japan in 2006. We report here the status of linezolid-resistant MRSAs in Japan. Eleven linezolid-resistant clinical isolates from 11 patients at six hospitals were collected from 2006 through 2008. The minimal inhibitory concentration (MIC) of linezolid in these strains varied from 8 to 64 μg/ml. All strains had at least one G2576T mutation in the chromosomal gene(s) encoding domain V of the 23S ribosomal RNA (rRNA). Chromosomal DNA encoding five copies of the domain V region was analyzed by polymerase chain reaction (PCR). Strains with the linezolid MICs of 64, 32, 16, and 8 μg/ml had the G2576T mutation(s) in four, three (or four), two, and one copy of the 23S rRNA genes, respectively. These results suggest that the level of linezolid resistance seems to be roughly correlated with the number of mutations in the genes encoding 23S rRNA. DNA samples from all 11 strains were subjected to pulsed-field gel electrophoresis and were classified into seven independent clones having >92% identity. Among the 11 patients, five had been treated with linezolid and the remainder, in two hospitals, had no history of prior linezolid use. The results suggested possible nosocomial infections by linezolid-resistant MRSA.
2006年，日本批准了利奈唑胺在治疗耐甲氧西林金黄色葡萄球菌（MRSA）感染方面的有限使用。我们在此报告日本耐利奈唑胺MRSA的情况。从2006年到2008年，收集了来自6家医院11名患者的11株耐利奈唑胺临床分离株。这些菌株中利奈唑胺的最低抑菌浓度（MIC）在8至64μg/ml之间。所有菌株在编码23S核糖体RNA（rRNA）结构域V的染色体基因中至少有一个G2576T突变。通过聚合酶链反应（PCR）分析编码结构域V区域五个拷贝的染色体DNA。利奈唑胺MIC分别为64、32、16和8μg/ml的菌株在23S rRNA基因的四个、三个（或四个）、两个和一个拷贝中具有G2576T突变。这些结果表明，利奈唑胺耐药水平似乎与编码23S rRNA的基因突变数量大致相关。对所有11株菌株的DNA样本进行脉冲场凝胶电泳，分为7个具有>92%同一性的独立克隆。在这11名患者中，5名曾接受过利奈唑胺治疗，其余患者在两家医院中无先前使用利奈唑胺的病史。结果提示耐利奈唑胺MRSA可能存在医院感染。
