Tartof Sara Y, Solberg Owen D, Manges Amee R, Riley Lee W
Divisions of Epidemiology and Infectious Diseases and Immunity, 140 Warren Hall, School of Public Health, University of California at Berkeley, Berkeley, CA 94720, USA.
J Clin Microbiol. 2005 Dec;43(12):5860-4. doi: 10.1128/JCM.43.12.5860-5864.2005.
Although many strain typing methods exist for pathogenic Escherichia coli, most have drawbacks in terms of resolving power, interpretability, or scalability. For this reason, multilocus sequence typing (MLST) is an appealing alternative. However, its applicability to different pathogens in specific epidemiologic contexts is not well understood. Here, we applied a previously established MLST method based on housekeeping genes to a well-characterized collection of uropathogenic E. coli isolates to compare the discriminatory ability of this procedure with that of enterobacterial repeat intergenic consensus (ERIC2) PCR, serogrouping, and pulsed-field gel electrophoresis (PFGE). Among 45 E. coli isolates studied, 17 different multilocus sequence types (ST) were identified. One MLST group (designated ST69 complex) was comprised of 22 isolates, all belonging to uropathogenic and bacteremic E. coli strains previously defined as clonal group A (CgA) by ERIC2 PCR. The ST69 strains contained five different serogroups and 14 PFGE types. ERIC2 PCR CgA strains belonging to different MLST groups were also identified. Interestingly, one cow E. coli isolate, previously shown by PFGE to be closely related to a human uropathogenic CgA strain, was found to cluster with the ST69 strains. All of the other animal and environmental CgA isolates had different MLST profiles. The discriminatory power of this MLST method based on housekeeping genes appears to be higher than that of ERIC2 PCR but lower than that of PFGE for epidemiologic study of uropathogenic E. coli.
虽然存在多种用于致病性大肠杆菌的菌株分型方法，但大多数在分辨能力、可解释性或可扩展性方面存在缺陷。因此，多位点序列分型（MLST）是一种有吸引力的替代方法。然而，其在特定流行病学背景下对不同病原体的适用性尚不清楚。在此，我们将一种先前建立的基于管家基因的MLST方法应用于一组特征明确的尿路致病性大肠杆菌分离株，以比较该方法与肠杆菌重复基因间共有序列（ERIC2）PCR、血清分型和脉冲场凝胶电泳（PFGE）的鉴别能力。在所研究的45株大肠杆菌分离株中，鉴定出17种不同的多位点序列类型（ST）。一个MLST组（指定为ST69复合体）由22株分离株组成，所有这些分离株均属于先前通过ERIC2 PCR定义为克隆群A（CgA）的尿路致病性和菌血症性大肠杆菌菌株。ST69菌株包含五种不同的血清群和14种PFGE类型。还鉴定出属于不同MLST组的ERIC2 PCR CgA菌株。有趣的是，发现一株牛大肠杆菌分离株（先前通过PFGE显示与一株人类尿路致病性CgA菌株密切相关）与ST69菌株聚类。所有其他动物和环境CgA分离株具有不同的MLST谱。基于管家基因的这种MLST方法对于尿路致病性大肠杆菌的流行病学研究，其鉴别能力似乎高于ERIC2 PCR但低于PFGE。
