Department of Bacteriology II, National Institute of Infectious Diseases, Tokyo, Japan.
Toyokawa City Hospital, Aichi, Japan.
J Med Microbiol. 2010 May;59(Pt 5):556-562. doi: 10.1099/jmm.0.016147-0. Epub 2010 Feb 4.
A typing system for Clostridium difficile using sequencing of the surface-layer protein A encoding gene (slpA) was evaluated and used to analyse clinical isolates in Japan. A total of 160 stool specimens from symptomatic patients in Japan was examined and 87 C. difficile isolates were recovered. slpA sequence typing was found to have reliable typability and discriminatory power in comparison with PCR ribotyping, and the typing results were highly reproducible and comparable. slpA sequence typing was used to type C. difficile in DNA extracted directly from stool specimens. Among the 90 stool specimens in which direct typing results were obtained, 77 specimens were positive for C. difficile culture, and typing results from isolated strains agreed with those from direct typing in all 77 specimens. The slpA sequence type smz was dominant at all four hospitals examined, and this endemic type was detected by culture and/or direct typing in 61 (62 %) of 99 stool specimens positive for toxic culture and/or direct slpA sequence typing. Comparison of epidemic strains reported throughout the world revealed one isolate identified as slpA sequence type gc8, which was found to correspond to PCR ribotype 027 (BI/NAP1/027), whereas no isolates were found with the slpA gene identical to that of PCR ribotype 078 strain. slpA sequence typing is valuable for comparison of C. difficile strains epidemic in diverse areas because the typing results are reproducible and can easily be shared. In addition, slpA sequence typing could be applied to direct typing without culture.
采用测序表面层蛋白 A 编码基因 (slpA) 的方法对艰难梭菌进行分型，并用于分析日本的临床分离株。对来自日本有症状患者的 160 份粪便标本进行了检测，共回收了 87 株艰难梭菌。与 PCR 核糖体分型相比，slpA 序列分型具有可靠的可分型性和区分能力，且分型结果具有高度可重复性和可比性。slpA 序列分型用于直接从粪便标本中提取的 DNA 对艰难梭菌进行分型。在获得直接分型结果的 90 份粪便标本中，77 份为艰难梭菌培养阳性，且分离株的分型结果与所有 77 份标本的直接分型结果一致。smz 型 slpA 序列是所有 4 家检测医院的主要流行型，在所有 99 份毒素培养和/或直接 slpA 序列分型阳性的粪便标本中，通过培养和/或直接分型检测到 61 份 (62%) 存在这种地方性流行型。与世界各地报道的流行株进行比较，发现 1 株被鉴定为 slpA 序列型 gc8，其与 PCR 核糖体型 027 (BI/NAP1/027) 相对应，而未发现与 PCR 核糖体型 078 菌株具有相同 slpA 基因的菌株。slpA 序列分型对于比较不同地区流行的艰难梭菌菌株具有重要价值，因为分型结果具有可重复性，并且易于共享。此外，slpA 序列分型可应用于无需培养的直接分型。
