Department of Veterinary Services, Kwara State Ministry of Agriculture and Rural Development, Ilorin, Kwara State, Nigeria; Department of Veterinary Public Health and Preventive Medicine, Faculty of Veterinary Medicine, University of Ibadan, Oyo State, Nigeria; Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Finland.
Veterinary Microbiology Laboratory, University of Ilorin Veterinary Teaching Hospital, Ilorin, Kwara State, Nigeria.
J Glob Antimicrob Resist. 2022 Dec;31:337-344. doi: 10.1016/j.jgar.2022.11.002. Epub 2022 Nov 12.
The occurrence of multidrug-resistant (MDR) bacteria in poultry poses the public health threat of zoonotic transmission to humans. Hence, this study assessed the occurrence of drug-resistant Escherichia coli in broilers in the largest live bird market in Kwara State, Nigeria in December 2020.
Presumptive E. coli isolates were isolated using the European Union Reference Laboratory guideline of 2017 and confirmed via matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF/MS). Broth microdilution was performed on confirmed E. coli isolates to determine the minimum inhibitory concentration. Five extensively drug-resistant (XDR) isolates were selected for Illumina whole genome sequencing to predict the resistome, phylotype, sequence type, serotype, and diversity of mobile genetic elements in these isolates.
Of the 181 broiler caecal samples, 73 E. coli isolates were obtained, of which 67 (82.0%) and 37 (50.6%) were determined as MDR (resistant to at least three classes of antibiotics) and XDR (resistant to at least five classes of antibiotics), respectively. Whole genome sequencing revealed diverse sequence types, phylogroups, and serotypes (ST165/B1 - O80:H19, ST115/A - Unknown: H7, ST901/B1 - O109:H4, ST4087/F - O117:H42, and ST8324/A - O127:H42). The XDR E. coli isolates encoded resistance to fluoroquinolones, fosfomycin, sulfamethoxazole, ampicillin and cephalosporins, trimethoprim, aminoglycosides, chloramphenicol, tetracycline, and macrolides. Mutations in the gyrA gene conferring resistance to fluoroquinolones were also detected. There was a positive correlation between phenotypic resistance patterns and the antibiotic resistance genes that were detected in the sequenced isolates. The XDR isolates also harbored two disinfectant resistance genes (qacE and sitABCD) that conferred resistance to hydrogen peroxide and quaternary ammonium compounds, respectively. The genome of the XDR isolates harbored several mobile genetic elements and virulence-associated genes, which were conserved in all sequenced XDR isolates.
This is the first report of co-carriage of antibiotic resistance genes and disinfectant resistance genes in E. coli isolated from broilers in Ilorin, Nigeria. Our findings suggest that poultry are potential carriers of clonally diverse, pathogenic, MDR/XDR E. coli, which may have detrimental zoonotic potentials on human health.
禽中多药耐药（MDR）细菌的出现对人类构成了动物传染病传播的公共卫生威胁。因此，本研究评估了 2020 年 12 月在尼日利亚夸拉州最大的活禽市场中肉鸡中耐药大肠杆菌的发生情况。
使用欧盟参考实验室 2017 年的指南分离推定的大肠杆菌分离株，并通过基质辅助激光解吸/电离时间飞行质谱（MALDI-TOF/MS）进行确认。对确认的大肠杆菌分离株进行肉汤微量稀释，以确定最小抑菌浓度。选择 5 种广泛耐药（XDR）分离株进行 Illumina 全基因组测序，以预测这些分离株中的耐药组、 phylotype、序列型、血清型和移动遗传元件的多样性。
在 181 个肉鸡盲肠样本中，获得了 73 株大肠杆菌分离株，其中 67 株（82.0%）和 37 株（50.6%）被确定为 MDR（至少对三类抗生素耐药）和 XDR（至少对五类抗生素耐药）。全基因组测序显示出不同的序列型、 phylogroups 和血清型（ST165/B1-O80:H19、ST115/A-Unknown:H7、ST901/B1-O109:H4、ST4087/F-O117:H42 和 ST8324/A-O127:H42）。XDR 大肠杆菌分离株编码对氟喹诺酮类、磷霉素、磺胺甲恶唑、氨苄西林和头孢菌素、甲氧苄啶、氨基糖苷类、氯霉素、四环素和大环内酯类的耐药性。还检测到了导致氟喹诺酮类耐药的 gyrA 基因突变。表型耐药模式与测序分离株中检测到的抗生素耐药基因之间存在正相关。XDR 分离株还携带两种消毒剂耐药基因（qacE 和 sitABCD），分别对过氧化氢和季铵化合物具有耐药性。XDR 分离株的基因组还携带几种移动遗传元件和毒力相关基因，这些基因在所有测序的 XDR 分离株中都保守。
这是首次在尼日利亚伊洛林从肉鸡中分离的大肠杆菌中报告携带抗生素耐药基因和消毒剂耐药基因。我们的研究结果表明，家禽可能是具有克隆多样性、致病性、多药耐药/广泛耐药大肠杆菌的潜在携带者，这可能对人类健康产生有害的动物传染病潜力。
