Objective: To evaluate the typing and clinical application effect based on clustered regularly interspaced short palindromic repeats (CRISPRs), serotype, and Multilocus Sequence Typing (MLST). Methods: The spacers, serotype and sequence type (ST) were obtained with CRISPRsFinder, SeroTypeFinder and MLST. PCR was used to amplify the CRISPRs, and the spacers were used to predict serotype and ST, then comparing with the serotype and ST. Results: We defined the I-E CRISPR/Cas as CT-Ⅰ, I-F CRISPR/Cas as CT-Ⅱ, and only CRISPR3-4 as CT-Ⅲ. We designated each unique arrangement spacer profile as a unique CRISPRs type. A total of 79 CT types, 76 serotypes, and 66 STs were identified. The CRISPRs typing was the most discriminating, with the Simpson index of 0.936, having the highest correlation with serology with the adjusted Rand index of 0.908. The CRISPRs type could divide the same serotype (ST) into two subtypes [O157∶H7(ST11), O104∶H4(ST678), and O26∶H11(ST21)]. The detection rates of CRISPR1, CRISPR2, CRISPR3, CRISPR4, and CRISPR3-4 were 81.1%, 94.5%, 1.4%, 1.4%, and 4.6%, with the accuracy rate of 95.0% and 100.0% according to the spacers to forecast O157∶H7 (ST11) and ST131. Conclusion: Based on the CRISPRs spacer, this method can be used as an essential molecular typing for E.coli, as it presents a good typing and clinical application effect.
目的： 评价并验证成簇规律间隔短回文重复序列（CRISPRs）、血清学和多位点测序分型（MLST）方法对大肠埃希菌分型的效果。 方法： 使用CRISPRsFinder分析大肠埃希菌全基因组序列的CRISPRs间隔序列，使用在线软件SeroTypeFinder和 MLST获得血清型和序列型（ST）；采用PCR扩增并分析349株大肠埃希菌CRISPRs，使用CRISPRs间隔序列预测血清型和ST，并比较血清学和MLST分型结果。 结果： 将I-E型CRISPR/Cas、I-F型CRISPR/Cas和CRISPR3-4分别命名CT-Ⅰ、CT-Ⅱ和CT-Ⅲ。根据CRISPRs间隔序列构成和排列进一步进行分型，203株大肠埃希菌被分为79个CT型别，76个血清型和66个ST。CRISPRs分型的区分能力最强，辛普森指数为0.936。CRISPRs和血清学的关联程度最高，调整兰德指数为0.908。CRISPRs型能进一步区分相同血清或ST产志贺毒素的大肠埃希菌［O157∶H7（ST11）、O104∶H4（ST678）和O26∶H11（ST21）］菌株。扩增实验室菌株的CRISPR1、CRISPR2、CRISPR3、CRISPR4和CRISPR3-4，检出率分别为81.1%、94.5%、1.4%、1.4%和4.6%；根据CRISPRs间隔序列预测O157∶H7（ST11）和ST131准确率分别为95.0%和100.0%。 结论： 基于CRISPRs的大肠埃希菌的分子分型方法呈现较好的分型效果和临床应用效果，预期可以成为大肠埃希菌分型的重要分子标志物。.