1 Department of Diagnostic Medicine and Pathobiology, Kansas State University, Manhattan, Kansas 66506.
2 U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, Division of Molecular Biology, Laurel, Maryland 20708, USA.
J Food Prot. 2019 Mar;82(3):395-404. doi: 10.4315/0362-028X.JFP-18-393.
Shiga toxin-producing Escherichia coli (STEC) serogroups O26, O45, O103, O111, O121, and O145, referred to as the top six non-O157 serogroups, are responsible for more than 70% of human non-O157 STEC infections in North America. Cattle harbor non-O157 strains in the hindgut and shed them in the feces. The objective of this study was to use the U.S. Food and Drug Administration (FDA) E. coli identification (ECID) DNA microarray to identify the serotype, assess the virulence potential of each, and determine the phylogenetic relationships among five of the six non-O157 E. coli serogroups isolated from feedlot cattle feces. Forty-four strains of STEC, enterohemorrhagic E. coli (EHEC), enteropathogenic E. coli (EPEC), or putative nonpathotype E. coli (NPEC) of cattle origin and five human clinical strains of EHEC were assayed with the FDA-ECID DNA microarray. The cattle strains harbored diverse flagellar genes. The bovine and human strains belonging to serogroups O26, O45, and O103 carried stx only, O111 carried both stx and stx, and O145 carried either stx or stx. The strains were also positive for various subtypes of intimin and other adhesins (IrgA homologue adhesin, long polar fimbriae, mannose-specific adhesin, and curli). Both human and cattle strains were positive for LEE-encoded type III secretory system genes and non-LEE-encoded effector genes. SplitsTree4, a program used to determine the phylogenetic relationship among the strains, revealed that the strains within each serogroup clustered according to their pathotype. In addition to genes encoding Shiga toxins, bovine non-O157 E. coli strains possessed other major virulence genes, including those for adhesins, type III secretory system proteins, and plasmid-borne virulence genes, similar to human clinical strains. Because virulence factors encoded by these genes are involved in the pathogenesis of various pathotypes of E. coli, the bovine non-O157 strains could cause human illness. The FDA-ECID DNA microarray assay rapidly provided a profile of the virulence genes for assessment of the virulence potential of each strain.
产志贺毒素大肠杆菌（STEC）血清群 O26、O45、O103、O111、O121 和 O145，被称为前六大非 O157 血清群，导致北美的人类非 O157 STEC 感染超过 70%。牛在后肠中携带非 O157 菌株，并将其排泄在粪便中。本研究的目的是使用美国食品和药物管理局（FDA）大肠杆菌鉴定（ECID）DNA 微阵列来鉴定血清型，评估每个菌株的毒力潜力，并确定从牛粪便中分离的六种非 O157 大肠杆菌血清群中的五种的系统发育关系。用 FDA-ECID DNA 微阵列检测了 44 株来自牛的产志贺毒素大肠杆菌（STEC）、肠出血性大肠杆菌（EHEC）、肠致病性大肠杆菌（EPEC）或假定非致病性大肠杆菌（NPEC）以及 5 株人类临床 EHEC 菌株。牛株携带多样化的鞭毛基因。属于血清群 O26、O45 和 O103 的牛和人类菌株仅携带 stx，O111 携带 stx 和 stx，O145 携带 stx 或 stx。这些菌株还对各种类型的紧密素和其他黏附素（IrgA 同源黏附素、长极鞭毛、甘露糖特异性黏附素和卷曲）呈阳性。人和牛株均对 LEE 编码的 III 型分泌系统基因和非 LEE 编码的效应基因呈阳性。用于确定菌株间系统发育关系的 SplitsTree4 程序显示，每个血清群内的菌株根据其病原型聚类。除了编码志贺毒素的基因外，牛非 O157 大肠杆菌菌株还具有其他主要毒力基因，包括黏附素、III 型分泌系统蛋白和质粒携带的毒力基因，与人类临床菌株相似。由于这些基因编码的毒力因子参与各种大肠杆菌病原型的发病机制，牛非 O157 菌株可能导致人类疾病。FDA-ECID DNA 微阵列检测快速提供了每个菌株毒力基因的图谱，用于评估每个菌株的毒力潜力。
