Laboratory of Hygiene of Foods of Animal Origin, Faculty of Veterinary Medicine, University of Thessaly, 43100 Karditsa, Greece.
Food Microbiol. 2009 Dec;26(8):865-71. doi: 10.1016/j.fm.2009.06.002. Epub 2009 Jun 10.
The examination of 2005 raw bovine (n = 950), caprine (n = 460) and ovine (n = 595) bulk milk samples collected throughout several regions in Greece for the presence of Escherichia coli serogroup O157 resulted in the isolation of 29 strains (1.4%) of which 21 were isolated from bovine (2.2%), 3 from caprine (0.7%) and 5 from ovine (0.8%) milk. Out of the 29 E. coli O157 isolates, only 12 (41.4%) could be classified as Shiga-toxigenic based on immunoassay and PCR results. All 12 Shiga-toxigenic E. coli serogroup O157 isolates belonged to the E. coli O157:H7 serotype. All except one of the 12 Shiga-toxin positive isolates were stx(2)-positive, five of which were also stx(1)-positive. The remaining isolate was positive only for the stx(1) gene. All stx-positive isolates (whether positive for stx(1), stx(2) or stx(1) and stx(2)) were also PCR-positive for the eae and ehxA genes. The remaining 17 E. coli O157 isolates (58.6%) were negative for the presence of the H7 flagellar gene by PCR, tested negative for Shiga-toxin production both by immunoassay and PCR, and among these, only four and three strains were PCR-positive for the eae and ehxA genes, respectively. All 29 E. coli O157 isolates displayed resistance to a wide range of antimicrobials, with the stx-positive isolates being, on average, resistant to a higher number of antibiotics than those which were stx-negative.
对希腊多个地区采集的 2005 份牛（n=950）、山羊（n=460）和绵羊（n=595）批量奶样进行了检测，以确定是否存在大肠杆菌 O157 血清群。结果从 29 株（1.4%）分离株中分离出 21 株来自牛（2.2%），3 株来自山羊（0.7%），5 株来自绵羊（0.8%）。在 29 株大肠杆菌 O157 分离株中，只有 12 株（41.4%）通过免疫检测和 PCR 结果可被归类为志贺毒素阳性。这 12 株志贺毒素阳性大肠杆菌 O157 血清群 O157 分离株均属于大肠杆菌 O157：H7 血清型。除 1 株外，其余 12 株志贺毒素阳性分离株均为 stx(2)-阳性，其中 5 株也为 stx(1)-阳性。其余分离株仅对 stx(1)基因呈阳性。所有 stx 阳性分离株（stx(1)、stx(2)或 stx(1)和 stx(2)阳性）对 eae 和 ehxA 基因的 PCR 检测也均呈阳性。其余 17 株大肠杆菌 O157 分离株（58.6%）通过 PCR 检测 H7 鞭毛基因均呈阴性，通过免疫检测和 PCR 检测均为志贺毒素阴性，其中 4 株和 3 株分别对 eae 和 ehxA 基因的 PCR 检测呈阳性。所有 29 株大肠杆菌 O157 分离株对多种抗生素均具有耐药性，stx 阳性分离株平均对更多种类的抗生素具有耐药性，而 stx 阴性分离株则不然。
