Laboratorio de Referencia de E. coli, Departamento de Microbiología y Parasitología, Facultad de Veterinaria, Universidad de Santiago de Compostela, Lugo, Spain.
Appl Environ Microbiol. 2012 Apr;78(8):2578-85. doi: 10.1128/AEM.07520-11. Epub 2012 Feb 3.
The objectives of this study were to investigate the presence of Shiga toxin-producing Escherichia coli (STEC) strains in wildlife that have spread in Europe, living near human settlements; to analyze their epidemiological role in maintenance and transmission to domestic livestock; and to assess the potential health risk of wildlife-carried strains. STEC strains were recovered from 53% of roe deer, 8.4% of wild boars, and 1.9% of foxes sampled in the northwest of Spain (Galicia). Of the 40 serotypes identified, 21 were classified as seropathotypes associated with human disease, accounting for 81.5% of the wildlife-carried STEC strains, including the enterohemorrhagic serotypes O157:H7-D-eae-γ1, O26:[H11]-B1-eae-β1, O121:H19-B1-eae-ε1, and O145:[H28]-D-eae-γ1. None of the wildlife-carried strains belonged to the highly pathogenic serotype O104:H4-B1 from the recent Germany outbreak. Forty percent of wildlife-carried STEC strains shared serotypes, phylogroups, intimin types, and Stx profiles with isolates from human patients from the same geographic area. Furthermore, wildlife-carried strains belonging to serotypes O5:HNM-A, O26:[H11]-B1, O76:H19-B1, O145:[H28]-D, O146:H21-B1, and O157:H7-D showed pulsed-field gel electrophoresis (PFGE) profiles with >85% similarity to human-pathogenic STEC strains. We also found a high level of similarity among STEC strains of serotypes O5:HNM-A, O26:[H11]-B1, and O145:HNM-D of bovine (feces and beef) and wildlife origins. Interestingly, O146:H21-B1, the second most frequently detected serotype in this study, is commonly associated with human diarrhea and isolated from beef and vegetables sold in Galicia. Importantly, at least 3 STEC isolates from foxes (O5:HNM-A-eae-β1, O98:[H21]-B1-eae-ζ1, and O146:[H21]-B1) showed characteristics similar to those of human STEC strains. In conclusion, roe deer, wild boar, and fox in Galicia are confirmed to be carriers of STEC strains potentially pathogenic for humans and seem to play an important role in the maintenance of STEC.
本研究的目的是调查在已扩散至欧洲人类聚居地的野生动物中是否存在产志贺毒素大肠杆菌（STEC）菌株；分析其在维持和传播至家畜中的流行病学作用；并评估野生动物携带菌株的潜在健康风险。在西班牙西北部（加利西亚）采集的 53%的獐鹿、8.4%的野猪和 1.9%的狐狸中分离到 STEC 菌株。在鉴定的 40 种血清型中，有 21 种被归类为与人类疾病相关的血清型，占野生动物携带的 STEC 菌株的 81.5%，包括肠出血性血清型 O157:H7-D-eae-γ1、O26:[H11]-B1-eae-β1、O121:H19-B1-eae-ε1 和 O145:[H28]-D-eae-γ1。来自德国最近暴发的高度致病血清型 O104:H4-B1 均未在野生动物携带的菌株中检出。40%的野生动物携带的 STEC 菌株与同一地理区域的人类患者分离株具有相同的血清型、 phylogroups、intimin 型和 Stx 谱。此外，属于血清型 O5:HNM-A、O26:[H11]-B1、O76:H19-B1、O145:[H28]-D、O146:H21-B1 和 O157:H7-D 的野生动物携带菌株的脉冲场凝胶电泳（PFGE）图谱相似度>85%，与人类致病性 STEC 菌株相似。我们还发现，来自牛（粪便和牛肉）和野生动物的 O5:HNM-A、O26:[H11]-B1 和 O145:HNM-D 血清型 STEC 菌株之间存在高度相似性。有趣的是，本研究中第二常见的检测到的血清型 O146:H21-B1 通常与人类腹泻有关，且从加利西亚销售的牛肉和蔬菜中分离得到。重要的是，至少有 3 株来自狐狸的 STEC 分离株（O5:HNM-A-eae-β1、O98:[H21]-B1-eae-ζ1 和 O146:[H21]-B1）显示出与人类 STEC 菌株相似的特征。总之，加利西亚的獐鹿、野猪和狐狸被证实为携带对人类具有潜在致病性的 STEC 菌株的宿主，并且似乎在 STEC 的维持中发挥重要作用。
