重复序列PCR与多位点分型技术在热带假丝酵母菌基因分型中的比较

Comparative study on genotyping of Candida tropicalis by repetitive sequence-based PCR and multilocus sequence typing

目的分析比较重复序列聚合酶链反应(REP-PCR)与多位点分型技术(MLST)在热带假丝酵母菌基因分型中的应用。方法收集来自5个地区6家医院的147株热带假丝酵母菌,分别以Ca-21、Ca-22、Com-21两两组合为引物,选用最合适的引物对进行REP-PCR后通过电泳获得REP-PCR型。在不同型别中各挑选3株采用MLST法扩增热带假丝酵母菌的6个管家基因,扩增片段测序后与数据库比对得到相应的序列型(sequencetype,ST)。结果 REP-PCR以Com21-Com21为引物对分型效果最好,REP-PCR与MLST分型结果一致。147株热带假丝酵母菌产生A～H共8种REP-PCR型,分别对应MLST的ST146、新型1、ST136、ST127、ST177、ST169、新型2和ST117。结论 REP-PCR与MLST在热带假丝酵母菌的基因分型中分辨率相同,而REP-PCR更为方便迅速,可作为实验室大量菌株分型的首选方法。

Objective To compare repetitive sequence-based polymerase chain reaction(REP-PCR)and multilocus sequence typing(MLST)in genotyping of Candida tropicalis.Methods REP-PCR was performed on 147 clinical isolates of Candida tropicalis collected from 6 hospitals of 5 provinces.Primer Ca-21,Ca-22 and Com-21 were used pairly to find the most suitable pair.Three isolates of Candida tropicalis from different REP-PCR types were tested by MLST.Six loci in housekeeping genes were sequenced after amplification,which were compared with the MLST database to obtain sequence type(ST).Results Eight REP-PCR types were found in 147 isolates of Candida tropicalis with primer Com21-Com21,which had the best genotyping effect.Type A-H were corresponding with ST146,NEW1,ST136,ST127,ST177,ST169,NEW2 and ST117 by MLST respectively.Conclusions REP-PCR offers a simple and rapid method for molecular typing,which has a similar discriminatory power with MLST.Therefore,REP-PCR can be the first choice in laboratory,especially for a large number of isolates.