33株艰难梭菌临床分离株的多位点序列分型

Multilocus sequence typing of 33 clinical Clostridium difficile isolates

目的 了解我国石家庄地区艰难梭菌临床分离株的多位点序列分型（MLST）情况.方法 回顾性研究.收集2010年7月至2011年12月石家庄市两家医院成人腹泻患者分离的33株艰难梭菌,并对其进行PCR毒素基因检测、PCR核糖体分型和MLST.采用START2系统进行统计学分析.结果 所分离的33株艰难梭菌中共检出10种ST型别（ST2/3/4/35/37/53/54/55/102/172）和12种核糖体型别,其中ST37/S Ⅰ（9/33,占27.3％）和ST54/SⅢ（8/33,占24.2％）是该地区流行的主要型别.ST172是新发现的ST型,已被MLST数据库收录.系统发育分析显示,其中6个ST型（ST2、ST3、ST4、ST53、ST54、ST102）位于一个较大组别,而ST35、ST37、ST55、ST172为零散型别.结论 在石家庄地区医院内成人腹泻患者分离的33株艰难梭菌以ST37和ST54型为主,并且医院间无明显的同源性.

Objective To investigate the multilocus sequence typing （MLST） for clinical Clostridium difficile isolates in Shijiazhuang of China. Methods A laboratory-based study was carried out retrospectively to characterize 33 C. difficile strains isolated from diarrhea patients during July 2010 to December 2011 according to toxin types, PCR ribotyping and MLST. START2 system was used to analyze the results. Results Ten ST types （ST 2/3/4/35/37/53/54/55/102/172 ） and 12 PCR ribotyping were identified in 33 C. difficile strains. The most prevalent ST types and PCR ribotyping were ST37/S I （9/33, 27.3% ） and ST54/SⅢ （8/33,24. 2% ）. ST172 was a new ST type reported firstly in the world,and has been included in the MLST database. Phylogenetic analysis also revealed that 6 STs （ ST2, ST3, ST4, ST53, ST54,ST102） were placed in one large group. Genotypes ST35, ST37, ST55, ST172 were considered as singletons. Conclusions The most common ST types for 33 clinical C. difficile strains isolated from Shijiazhuang were ST37 and ST54. No significant homology was found between ST types and hospitals.