Public Health and Zoonotic Diseases Research Group, Faculty of Veterinary Medicine, Universiti Malaysia Kelantan, Kota Bharu, 16100, Malaysia.
Department of Medical Microbiology and Immunology, College of Health Science, Mekelle University, Tigray, Ethiopia.
BMC Microbiol. 2024 Nov 26;24(1):499. doi: 10.1186/s12866-024-03653-2.
Extended spectrum beta-lactamase-producing Escherichia coli (ESBL-EC) is an increasing public health threat. This study aimed to determine the prevalence and characterization of ESBL-producing Escherichia coli (E. coli) isolated from broiler chicken and their farm environment, in Kelantan Malaysia.
Escherichia coli was isolated from 453 collected samples, including 210 cloacal swabs and 243 environmental samples. The antimicrobial susceptibility profile of the E. coli isolates was assessed for sixteen antibiotics using the disc diffusion method. The E. coli isolates were evaluated for phenotypic ESBL production using modified double disc synergy. After extraction of genomic DNA, ESBL resistance genes, phylogenetic group, and virulence genes were detected by PCR using appropriate primers. ESBL genes were further confirmed by sequencing. The molecular typing of E. coli strains was determined by Multilocus Sequence Typing (MLST).
A total of 93.8% (425/453) E. coli were isolated from the collected samples. Out of 334 E. coli isolates screened, 14.7% (49/334) were phenotypically ESBL producers. All the ESBL-EC were resistant to tetracycline, ciprofloxacin, and ampicillin. Thus, 100% of the ESBL-EC were multidrug resistant. Of the ESBL-EC 81.6% were positive for at least one ESBL encoding gene. The most prevalent ESBL gene detected was bla (77.6%; 38/49) followed by bla (32.7%; 16/49) and bla (18.4%; 9/49). The majority of ESBL-EC belonged to phylogenic groups A followed by B1 accounting for 44.9% and 12.2%, respectively. The most frequently identified sequence types were ST10 (n = 3) and ST206 (n = 3). The most detected virulence genes in the E. coli isolates were astA (33.3%; 22/66) followed by iss (15.2%; 10/66).
Our results show both broiler chicken and their respective farms environment were reservoirs of multi-drug resistant ESBL-producing E. coli and ESBL resistance genes.
产超广谱β-内酰胺酶的大肠杆菌（ESBL-EC）是日益严重的公共卫生威胁。本研究旨在确定马来西亚吉兰丹州肉鸡及其农场环境中分离的产 ESBL 大肠杆菌（E. coli）的流行率和特征。
从 453 份采集样本中分离大肠杆菌，包括 210 份泄殖腔拭子和 243 份环境样本。采用纸片扩散法评估 E. coli 分离株对 16 种抗生素的药敏谱。采用改良的双碟协同试验评估 E. coli 分离株的表型产 ESBL 能力。提取基因组 DNA 后，采用适当的引物通过 PCR 检测 ESBL 耐药基因、进化群和毒力基因。通过测序进一步确认 ESBL 基因。采用多位点序列分型（MLST）确定 E. coli 菌株的分子分型。
从采集的样本中总共分离出 93.8%（425/453）的大肠杆菌。在筛选的 334 株 E. coli 中，14.7%（49/334）为表型 ESBL 产生者。所有 ESBL-EC 对四环素、环丙沙星和氨苄西林均耐药。因此，100%的 ESBL-EC 为多药耐药菌。在 ESBL-EC 中，81.6%至少携带一种编码 ESBL 的基因呈阳性。检测到的最常见 ESBL 基因是 bla（77.6%；38/49），其次是 bla（32.7%；16/49）和 bla（18.4%；9/49）。大多数 ESBL-EC 属于 A 进化群，其次是 B1，分别占 44.9%和 12.2%。最常见的序列类型是 ST10（n=3）和 ST206（n=3）。在 E. coli 分离株中最常检测到的毒力基因是 astA（33.3%；22/66），其次是 iss（15.2%；10/66）。
我们的结果表明，肉鸡及其各自的农场环境都是多药耐药产 ESBL 大肠杆菌和 ESBL 耐药基因的储库。
