Laboratorio de Referencia de Escherichia coli (LREC), Departamento de Microbioloxía e Parasitoloxía, Facultade de Veterinaria, Universidade de Santiago de Compostela (USC), Lugo, Spain; Instituto de Investigación Sanitaria de Santiago de Compostela (IDIS), Santiago de Compostela, Spain.
Instituto de Investigación Sanitaria de Santiago de Compostela (IDIS), Santiago de Compostela, Spain; Unidad de Microbiología, Hospital Universitario Lucus Augusti (HULA), Lugo, Spain.
Vet Microbiol. 2021 Jan;252:108924. doi: 10.1016/j.vetmic.2020.108924. Epub 2020 Nov 9.
Shiga toxin-producing E. coli (STEC) and enterotoxigenic E. coli (ETEC) are the main agents of swine colibacillosis, an infectious disease which implies important economic losses. We characterized here 186 diarrheagenic E. coli from Spanish industrial pig farms (2005-2017) to know which clones were involved in this syndrome, and the rates of antibiotic resistance. The PCR based on pathotype-associated virulence genes determined that 161 of 186 isolates (86.5 %) exhibited the ETEC pathotype, 10 (5.4 %) the STEC pathotype, and 15 (8.1 %) the hybrid ETEC/STEC pathotype. The majority of the isolates showed phylogroup A (85.5 %), clonotype CH11-24 (72 %) and belonged to the clonal complex (CC) 10, including two ETEC clones accounting for around 50 % of the 186 isolates: O157:HNM-A-ST10 (CH11-24), which exhibited mostly the fimbrial antigen F4ac; and O108:HNM-A-ST10 (CH11-24), which exhibited mainly F18. Other associations were O139:H1-E-ST1 (CH2-54) with the STEC pathotype, and both O141:H4-A-CC10 (CH11-24) and O138:HNM-E-ST42 (CH28-41) with ETEC/STEC. We found that 87.1 % of the isolates were multidrug-resistant, including 9% ESBL-producers, with the highest rates to nalidixic acid (82 %), colistin (77 %), ticarcillin (76 %) and ampicillin (76 %). Besides, more than 50 % of isolates showed non-susceptibility to gentamicin, tobramycin, doxycycline, ciprofloxacin, trimethoprim-sufamethoxazole and chloramphenicol. Additionally, 11 out of 17 ESBL-producing isolates were mcr-carriers. Results suggest that O108:HNM-A-ST10 (CH11-24) F18 is an emerging clone taking space left by other classical serogroups. Further follow-up studies on predominant clones in pig colibacillosis are essential for the update of vaccines, as alternative to the use of antibiotics.
产志贺毒素大肠杆菌（STEC）和肠产毒性大肠杆菌（ETEC）是猪大肠杆菌病的主要病原体，这是一种传染性疾病，会造成重大的经济损失。我们对来自西班牙工业化养猪场的 186 株腹泻性大肠杆菌进行了特征描述（2005-2017 年），以了解哪些克隆体参与了这种综合征，并确定其抗生素耐药率。基于与病原菌相关的毒力基因的 PCR 检测表明，186 株分离株中有 161 株（86.5%）表现出 ETEC 病原型，10 株（5.4%）表现出 STEC 病原型，15 株（8.1%）表现出混合 ETEC/STEC 病原型。大多数分离株属于 A 群（85.5%），克隆型 CH11-24（72%），并属于克隆复合体（CC）10，其中包括两个 ETEC 克隆，占 186 株的 50%左右：O157:HNM-A-ST10（CH11-24），主要携带菌毛抗原 F4ac；O108:HNM-A-ST10（CH11-24），主要携带 F18。其他关联包括 O139:H1-E-ST1（CH2-54）与 STEC 病原型，O141:H4-A-CC10（CH11-24）和 O138:HNM-E-ST42（CH28-41）与 ETEC/STEC。我们发现，87.1%的分离株是多药耐药的，包括 9%的 ESBL 生产者，对萘啶酸（82%）、粘菌素（77%）、替卡西林（76%）和氨苄西林（76%）的耐药率最高。此外，超过 50%的分离株对庆大霉素、妥布霉素、强力霉素、环丙沙星、复方磺胺甲噁唑和氯霉素表现出非敏感性。此外，17 株产 ESBL 的分离株中有 11 株是 mcr 携带者。结果表明，O108:HNM-A-ST10（CH11-24）F18 是一种新兴的克隆体，正在填补其他经典血清群留下的空白。对猪大肠杆菌病中主要克隆体的进一步跟踪研究对于疫苗的更新至关重要，这是替代抗生素使用的方法。
