Department of Life Science and Engineering, Foshan University, Foshan, China; State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products and Institute of Agro-product Safety and Nutrition, Zhejiang Academy of Agricultural Sciences, Hangzhou, China.
State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products and Institute of Agro-product Safety and Nutrition, Zhejiang Academy of Agricultural Sciences, Hangzhou, China.
J Glob Antimicrob Resist. 2022 Sep;30:249-251. doi: 10.1016/j.jgar.2022.06.029. Epub 2022 Jul 3.
This study aimed to identify tigecycline-resistant tet(X4)-bearing Escherichia fergusonii isolated from pigs in China with a complete genome sequence.
E. fergusonii was isolated by selective medium and screened from tigecycline-supplemented agar plates. The microbroth dilution method was used for antimicrobial susceptibility testing, and the minimal inhibitory concentration (MIC) results refer to the interpretation standard in the Clinical and Laboratory Standards Institute of America (CLSI). Whole-genome sequencing was performed on the Illumina HiSeq and Nanopore GridION platforms. The antimicrobial resistance (AMR) genes virulence genes and replicon types of plasmids were predicted by the CGE server.
E. fergusonii EF21QZZ116 was identified from 760 faecal and caecal content samples and was resistant to tigecycline, tetracycline, ampicillin, sulfisoxazole, trimethoprim-sulfamethoxazole, spectinomycin, and florfenicol. The AMR genes tet(X4), bla, and floR are located on the hybrid IncFIA-IncHI1A-IncHI1B plasmid pQZZ166-tetX-190K and are 190 391 bp in length. This hybrid plasmid has high homology with the plasmids of Escherichia coli, Enterobacter cloacae, Klebsiella, Citrobacter, and Salmonella based on comparison and analysis with the NCBI database. Notably, conjugative transfer and S1 nuclease pulsed-field gel electrophoresis (S1-PFGE) assays show that the plasmid can transfer horizontally.
To the best of our knowledge, this is the first report of E. fergusonii carrying the tet(X4) gene isolated from a pig; this report provides insight into the AMR characteristics of E. fergusonii and offers insight into public health.
本研究旨在鉴定来自中国猪的携带完整基因组序列的替加环素耐药 tet(X4) 型弗格森埃希菌。
通过选择性培养基从替加环素补充琼脂平板中分离弗格森埃希菌。采用微量肉汤稀释法进行抗菌药物敏感性试验，最小抑菌浓度（MIC）结果参照美国临床和实验室标准协会（CLSI）的解释标准。采用 Illumina HiSeq 和 Nanopore GridION 平台进行全基因组测序。CGE 服务器预测抗菌药物耐药（AMR）基因、毒力基因和质粒的复制子类型。
从 760 份粪便和盲肠内容物样本中鉴定出一株弗格森埃希菌 EF21QZZ116，该菌对替加环素、四环素、氨苄西林、磺胺异噁唑、复方磺胺甲噁唑、大观霉素和氟苯尼考耐药。AMR 基因 tet(X4)、bla 和 floR 位于杂交 IncFIA-IncHI1A-IncHI1B 质粒 pQZZ166-tetX-190K 上，长度为 190 391 bp。该杂交质粒与 NCBI 数据库中的大肠杆菌、阴沟肠杆菌、肺炎克雷伯菌、柠檬酸杆菌和沙门氏菌的质粒高度同源。值得注意的是，接合转移和 S1 核酸酶脉冲场凝胶电泳（S1-PFGE）实验表明该质粒可进行水平转移。
据我们所知，这是首次从猪中分离出携带 tet(X4) 基因的弗格森埃希菌的报道；该报告揭示了弗格森埃希菌的 AMR 特征，为公共卫生提供了参考。
