Atiq Md Nowshad, Islam Md Saiful, Ullah Md Ashek, Chakroborty Nirab, Islam Raihana, Rana Md Liton, Ferdous Farhana Binte, Sobur Md Abdus, Khan Mohammad Ferdousur Rahman, Rahman Md Tanvir
Department of Microbiology and Hygiene, Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh.
Department of Microbiology and Hygiene, Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh; Department of Animal Science, University of California - Davis, Davis 95616, USA.
Res Vet Sci. 2025 Sep;193:105810. doi: 10.1016/j.rvsc.2025.105810. Epub 2025 Jul 14.
Avian pathogenic Escherichia coli (APEC) poses a major threat to poultry health and productivity, particularly in layer parent stock, resulting in substantial economic losses. This study aimed to determine the occurrence of APEC along with their virulence and resistance profile in the layer parent stock. A total of 89 samples, including cloacal swabs from 36 live birds and liver swabs from 53 dead birds, were collected. E. coli was isolated using culture, biochemical, and PCR methods. APEC-related virulence genes were detected via PCR, while antimicrobial susceptibility was evaluated using the disc diffusion method and PCR. The overall prevalence of E. coli was 82 %, with similar detection rates in live (83.3 %) and dead birds (81.1 %). In PCR, APEC-associated gene fimC was detected in 95.9 % of the isolates, papC in 36.9 %, and iucD in 15.1 %, with no significant difference between those from live and dead birds. All isolates were multidrug-resistant, where all E. coli isolates from both live and dead birds were resistant to ampicillin (100 %), with high resistance to cefotaxime (live: 100 % vs. dead: 93 %), tetracycline (80 % vs. 88.4 %), nalidixic acid (100 % vs. 62.8 %), streptomycin (66 % vs. 39.5 %), norfloxacin (40 % vs. 20.9 %), and chloramphenicol (20 % vs. 25.6 %). Moreover, genes conferring resistance to tetracyclines [tetA (live: 10/10 vs. dead: 10/10) and tetB (1/10 vs. 10/10)] and beta-lactams [bla (10/10 vs. 10/10), bla (1/10 vs. 4/10), and bla (2/10 vs. 0/10)] were detected in isolated E. coli. The results recommend periodic surveillance and policy interventions to mitigate health risks and economic losses.
禽致病性大肠杆菌（APEC）对家禽健康和生产力构成重大威胁，尤其是对蛋种鸡，会造成巨大经济损失。本研究旨在确定蛋种鸡中APEC的发生率及其毒力和耐药情况。共采集了89份样本，包括36只活禽的泄殖腔拭子和53只死禽的肝脏拭子。采用培养、生化和PCR方法分离大肠杆菌。通过PCR检测与APEC相关的毒力基因，同时使用纸片扩散法和PCR评估抗菌药物敏感性。大肠杆菌的总体患病率为82%，在活禽（83.3%）和死禽（81.1%）中的检出率相似。在PCR检测中，95.9%的分离株检测到APEC相关基因fimC，36.9%检测到papC，15.1%检测到iucD，活禽和死禽分离株之间无显著差异。所有分离株均对多种药物耐药，活禽和死禽的所有大肠杆菌分离株均对氨苄西林耐药（100%），对头孢噻肟耐药率较高（活禽：100%，死禽：93%），对四环素耐药率分别为80%和88.4%，对萘啶酸耐药率分别为100%和62.8%，对链霉素耐药率分别为66%和39.5%，对诺氟沙星耐药率分别为40%和20.9%，对氯霉素耐药率分别为20%和25.6%。此外，在分离的大肠杆菌中检测到赋予对四环素耐药的基因[tetA（活禽：10/10，死禽：10/10）和tetB（1/十，10/10）]以及对β-内酰胺类耐药的基因[bla（10/10，10/10）、bla（1/10，4/10）和bla（2/10，0/10）]。研究结果建议进行定期监测和采取政策干预措施，以降低健康风险和经济损失。
