福建农业学报2026，Vol.41Issue(2)：170-181,12.DOI:10.19303/j.issn.1008-0384.2026.02.004
一株仔猪腹泻源多重耐药大肠杆菌的分离鉴定及其生物学特性
Isolation,Identification,and Characterization of a Multidrug-Resistant Diarrheagenic Escherichia coli from Piglets
摘要
Abstract
[Objective]To isolate and identify Escherichia coli(E.coli)from the intestinal contents of dead piglets,and to evaluate its virulence,drug resistance,and pathogenicity.This study aims to investigate the etiology of yellowish-white diarrhea in piglets on a farm in Fujian Province,thereby providing a basis for precise clinical medication and effective prevention and control.[Method]Intestinal contents were collected from diarrheic deceased piglets.Pathogen isolation and identification were performed using selective culture,Gram staining,biochemical tests,16S rRNA gene amplification,and serotyping.Virulence and resistance characteristics were analyzed through virulence gene detection,resistance gene detection,antimicrobial susceptibility testing,and mouse pathogenicity testing.[Result]A pathogenic strain was isolated,which formed red colonies on MacConkey(MAC)agar and pale yellow colonies on xylose lysine deoxycholate(XLD)agar.Gram staining revealed Gram-negative short rods.16S rRNA gene sequencing showed＞99%sequence similarity to E.coli sequences in GenBank,confirming its identification as E.coli.Serotyping identified it as O2.Virulence gene detection showed the strain carried irp2,iucD,and sta genes.Resistance gene detection revealed it simultaneously harbored 11 resistance genes,including those for quinolones,tetracyclines,β-lactams,macrolides,phenicols,and sulfonamides.Antimicrobial susceptibility testing demonstrated resistance to 15 agents including ofloxacin,streptomycin,ampicillin,tetracycline,erythromycin,lincomycin,and sulfisoxazole,while exhibiting sensitivity to amikacin and spectinomycin.Mouse pathogenicity testing confirmed the isolate was pathogenic,with a median lethal dose(LD50)of 1.60×108 CFU.[Conclusion]This study isolated an O2 serotype diarrheagenic E.coli strain from piglets in a large-scale pig farm in Fujian Province.The strain carries multiple virulence genes,exhibits severe multidrug resistance,and is highly pathogenic,providing important insights for the monitoring and control of colibacillosis in the Fujian region.关键词
大肠杆菌/致病性/毒力基因/耐药基因/半数致死量Key words
Escherichia coli/pathogenicity/virulence genes/drug resistance genes/median lethal dose分类
农业科技引用本文复制引用
杨圆,戴爱玲,刘建奎,魏春华,蓝欣,罗程,陈昊宇,颜一雪,魏维,岑明升,谢妃敏,李雪静..一株仔猪腹泻源多重耐药大肠杆菌的分离鉴定及其生物学特性[J].福建农业学报,2026,41(2):170-181,12.基金项目
福建省科技厅引导项目(2025N0012、2021N0032) （2025N0012、2021N0032）
中央引导地方科技发展专项(2021L3028) （2021L3028）
福建省自然科学基金项目(2023J01989) （2023J01989）
