Department of Clinical Laboratory, National Hospital Organization, Nagoya Medical Center, 4-1-1, Sannomaru, Naka-ku, Nagoya, Aichi Prefecture 460-0001, Japan.
Division of Bacteriology, Osaka Institute of Public Health, Nakamichi 1-3-69, Higashinari-ku, Osaka 537-0025, Japan.
Diagn Microbiol Infect Dis. 2019 Dec;95(4):114883. doi: 10.1016/j.diagmicrobio.2019.114883. Epub 2019 Aug 10.
This study reports the first isolation and characterization of a vanD5 genotype vancomycin-resistant Enterococcus faecium strain (E. faecium IPHb306) recovered from a 79-year-old Japanese female inpatient. Species identification was determined by biochemical testing, matrix-assisted laser desorption ionization-time of flight mass spectrometry, and species-specific PCR. Susceptibility tests indicated that E. faecium IPHb306 was resistant to vancomycin but susceptible to teicoplanin. Southern hybridization analyses indicated that E. faecium IPHb306 harbored a vanD5 gene cluster on chromosomal DNA. Growth curve analyses showed that a vancomycin resistance phenotype could be inducible. Sequencing analyses of the vanD5 gene cluster and the ddl gene demonstrated several point mutations were present. Because this strain belongs to ST203, a major hospital-adapted lineage, spread of the vanD5 genotype E. faecium ST203 is considered a clinical threat in Japan.
本研究报告了首例从一名 79 岁日本女性住院患者中分离和鉴定的 vanD5 基因型万古霉素耐药屎肠球菌(E. faecium IPHb306)。通过生化试验、基质辅助激光解吸电离飞行时间质谱和种特异性 PCR 确定了物种鉴定。药敏试验表明,E. faecium IPHb306 对万古霉素耐药,但对替考拉宁敏感。Southern 杂交分析表明,E. faecium IPHb306 携带染色体 DNA 上的 vanD5 基因簇。生长曲线分析表明,万古霉素耐药表型可诱导。vanD5 基因簇和 ddl 基因的测序分析表明存在几个点突变。由于该菌株属于 ST203,一种主要的医院适应谱系,因此,vanD5 基因型屎肠球菌 ST203 的传播被认为是日本的临床威胁。