Department of Veterinary Public Health and Epidemiology, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar, 125004, India.
Vet Res Commun. 2022 Jun;46(2):537-548. doi: 10.1007/s11259-021-09881-5. Epub 2022 Feb 3.
Avian pathogenic Escherichia coli (APEC) is responsible for colibacillosis in poultry. APEC remains a constant problem for the poultry industry, despite the use of antimicrobials and disinfectants in farms. The endemicity of APEC in poultry farms is associated with its biofilm-forming ability, which is further aggravated by various virulence factors and resistance to multiple drugs that help bacteria to thrive under different environmental conditions. To characterize APEC from affected broiler chickens and their environments, samples (n=114) from dead birds (heart, liver, lungs, and cloacal swab) and surrounding environments such as feeder, drinker, litter, PVC pipe, water tank wall, feed, and water were collected. The collected samples were subjected to microbial isolation using MacConkey Lactose agar (MLA) and Eosin Methylene Blue agar (EMB), which led to the isolation of 62 E. coli isolates. This was confirmed by uspA gene amplification and Vitek 2 Compact. These isolates were characterized using a set of five virulence genes (hlyF, ompT, iroN, iss, iutA), which yielded 47 (75.80%) isolates as APEC and the remaining as non-APEC. Furthermore, all the 62 isolates were subjected to microtiter plate assay for biofilm detection and the result showed that 36 (58.06%) isolates were able to form moderate to strong biofilms in Trypticase soy broth (TSB) at 72h of incubation. Of the 36 biofilm-producing isolates, 30 were APEC. Biofilm-related genes (crl, csgA, fimH, luxS, and papC) were also detected with higher prevalence among APEC isolates. Antimicrobial susceptibility test using Vitek 2 Compact revealed 43 (91.48%) of 47 APEC isolates as multiple drug resistant (MDR) and 8 (17.02%) as ESBL positive. This study reveals that APEC with biofilm formation ability is present in poultry farms. Further studies are needed to understand the role of biofilms in the pathogenesis and antimicrobial resistance of APEC.
禽致病性大肠杆菌（APEC）是家禽大肠杆菌病的病原体。尽管农场使用了抗生素和消毒剂，但 APEC 仍然是家禽业的一个持续问题。APEC 在家禽养殖场的流行与它形成生物膜的能力有关，而各种毒力因子和对多种药物的耐药性进一步加剧了这种情况，这些因素帮助细菌在不同的环境条件下茁壮成长。为了从受感染的肉鸡及其环境中对 APEC 进行特征描述，从病死鸡（心脏、肝脏、肺和泄殖腔拭子）和周围环境（如料槽、饮水器、垫料、PVC 管、水箱壁、饲料和水）采集了 114 个样本。收集的样本使用麦康凯乳糖琼脂（MLA）和曙红亚甲基蓝琼脂（EMB）进行微生物分离，共分离出 62 株大肠杆菌。这通过uspA 基因扩增和 Vitek 2 Compact 得到了确认。这些分离株使用一组 5 种毒力基因（hlyF、ompT、iroN、iss、iutA）进行了特征描述，结果显示 47 株（75.80%）为 APEC，其余为非 APEC。此外，所有 62 株分离株都进行了微量滴定板法生物膜检测，结果显示 36 株（58.06%）在 72 小时孵育时能够在胰蛋白酶大豆肉汤（TSB）中形成中度至强的生物膜。在 36 株产生物膜的分离株中，有 30 株为 APEC。还检测到与生物膜相关的基因（crl、csgA、fimH、luxS 和 papC）在 APEC 分离株中更为普遍。使用 Vitek 2 Compact 进行的抗菌药物敏感性测试显示，47 株 APEC 中有 43 株（91.48%）为多重耐药（MDR），8 株（17.02%）为 ESBL 阳性。本研究表明，具有生物膜形成能力的 APEC 存在于家禽养殖场中。需要进一步研究来了解生物膜在 APEC 发病机制和抗菌药物耐药性中的作用。
