Lugsomya Kittitat, Yindee Jitrapa, Niyomtham Waree, Tribuddharat Chanwit, Tummaruk Padet, Hampson David J, Prapasarakul Nuvee
1 Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University , Bangkok, Thailand .
2 Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University , Bangkok, Thailand .
Microb Drug Resist. 2018 Sep;24(7):1054-1066. doi: 10.1089/mdr.2018.0154.
The aims of this study were (i) to evaluate whether routine in-feed antimicrobial use in pigs or not resulted in differences in antimicrobial resistance (AMR) E. coli at different pig producing stages, and (ii) to determine whether resistant strains were presented in pig meat postslaughter. A total of 300 commensal E. coli isolates were obtained and examined for antibiograms, AMR genes, plasmid replicons, and molecular types. The isolates were from two farms either using (A) or not using in-feed antimicrobials (NA), sampled four times during the production cycle and once postslaughter. E. coli resistant to aminoglycosides containing aadA1, aadA2, and aadB and extended-spectrum beta-lactamase-producing (ESBLP) E. coli containing bla were significantly increased in the nursery and growing periods in farm A compared to farm NA. IncI1-Iγ and IncHI2 were common in the nursery period and were shown to transfer bla genes by conjugation. ST10 was the most common type only found in live pigs. ST604, ST877, ST1209, and ST2798 ESBLP were found only in live pigs, whereas ST72, ST302, and ST402 ESBLP were found in pig meat.
（i）评估猪日常饲料中使用抗菌药物与否是否会导致不同生猪生产阶段的大肠杆菌耐药性（AMR）存在差异，以及（ii）确定屠宰后的猪肉中是否存在耐药菌株。共获得300株共生大肠杆菌分离株，并对其进行抗菌谱、AMR基因、质粒复制子和分子类型检测。这些分离株来自两个农场，一个使用（A）饲料抗菌药物，另一个不使用（NA），在生产周期中采样四次，屠宰后采样一次。与NA农场相比，A农场保育期和生长期中对含有aadA1、aadA2和aadB的氨基糖苷类耐药的大肠杆菌以及产超广谱β-内酰胺酶（ESBLP）且含有bla的大肠杆菌显著增加。IncI1-Iγ和IncHI2在保育期很常见，并显示可通过接合转移bla基因。ST10是仅在生猪中发现的最常见类型。ST604、ST877、ST1209和ST2798 ESBLP仅在生猪中发现，而ST72、ST302和ST402 ESBLP在猪肉中发现。
