Sasoon Arina, Nikkhahi Farhad, Javadi Amir, Sabzi Samira, Deilamani Mohadeseh Ostovari, Kiaheyrati Niloofar, Karampour Amin, Peymani Amir, Fardsanei Fatemeh
Medical Microbiology Research Center, Qazvin University of Medical Sciences, Qazvin, Iran.
Student Research Committee, Qazvin University of Medical Sciences, Qazvin, Iran.
Vet Med Sci. 2025 Sep;11(5):e70510. doi: 10.1002/vms3.70510.
Escherichia coli affects human health through intestinal and extraintestinal infections. Avian pathogenic E. coli (APEC) contributes to colibacillosis in poultry and can develop public health risks. Antibiotic resistance and biofilm-producer strains are challenges in infection control options.
This study aimed to characterize phenotypic and genotypic antibiotic resistance profiles as well as biofilm formation assay in E. coli isolates from clinical and poultry samples.
In the study, 42 E. coli isolates were collected and confirmed from clinical and poultry sources. The isolates were evaluated for pathotypes using polymerase chain reaction (PCR). Antibiotic resistance was evaluated using the disk diffusion technique and minimum inhibitory concentration (MIC) tests. PCR was utilized to identify antimicrobial resistance genes associated with fluoroquinolones, sulphonamides, tetracyclines and beta-lactams. Biofilm formation was evaluated using a 96-well microtiter plate.
Three clinical isolates, including enteropathogenic E. coli (EPEC), enteroaggregative E. coli (EAEC) and enterotoxigenic E. coli (ETEC), were identified as pathogenic strains. The highest rates of resistance were recorded against tylosin (100%), neomycin (92.85%), tetracycline (85.7%), ampicillin (73.8%), doxycycline (71.4%), ciprofloxacin (64.28%), trimethoprim/sulfamethoxazole (64.28%) and enrofloxacin (57.1%). The most prevalent resistance genes detected as blaTEM and gyrA/B (97.6% and 76.1%, respectively). The overall prevalence of blaCTX, sul1, sul2, tetA and tetB genes were 21.4%, 45.2%, 11.9%, 33.3% and 7.1%, respectively. The qnrB, qnrB4 and qnrS genes were absent in the clinical samples, whereas present in poultry isolates. All isolates were biofilm producers, and 96.4% of poultry isolates had strong biofilm formation capacity.
The alarming levels of resistance genes and biofilm formation of isolates in the present study emphasize the need for antibiotic management practices and further research on resistance transmission dynamics in the food industry.
大肠杆菌通过肠道和肠道外感染影响人类健康。禽致病性大肠杆菌（APEC）会导致家禽发生大肠杆菌病，并可能引发公共卫生风险。抗生素耐药性和生物膜产生菌是感染控制方面的挑战。
本研究旨在对临床和家禽样本中分离出的大肠杆菌的表型和基因型抗生素耐药谱以及生物膜形成情况进行表征。
在本研究中，从临床和家禽来源收集并确认了42株大肠杆菌分离株。使用聚合酶链反应（PCR）对分离株的致病型进行评估。采用纸片扩散法和最低抑菌浓度（MIC）试验评估抗生素耐药性。利用PCR鉴定与氟喹诺酮类、磺胺类、四环素类和β-内酰胺类相关的抗菌耐药基因。使用96孔微量滴定板评估生物膜形成情况。
鉴定出三株临床分离株，包括肠致病性大肠杆菌（EPEC）、肠聚集性大肠杆菌（EAEC）和产肠毒素大肠杆菌（ETEC）为致病菌株。对泰乐菌素（100%）、新霉素（92.85%）、四环素（85.7%）、氨苄西林（73.8%）、强力霉素（71.4%）、环丙沙星（64.28%）、甲氧苄啶/磺胺甲恶唑（64.28%）和恩诺沙星（57.1%）的耐药率最高。检测到的最普遍的耐药基因是blaTEM和gyrA/B（分别为97.6%和76.1%）。blaCTX、sul1、sul2、tetA和tetB基因的总体流行率分别为21.4%、45.2%、11.9%、33.3%和7.1%。临床样本中未检测到qnrB、qnrB4和qnrS基因，而在家禽分离株中存在。所有分离株均为生物膜产生菌，96.4%的家禽分离株具有很强的生物膜形成能力。
本研究中分离株的耐药基因水平和生物膜形成情况令人担忧，这凸显了抗生素管理措施的必要性以及对食品行业耐药性传播动态进行进一步研究的重要性。
