中国兽医杂志2025，Vol.61Issue(7)：43-55,13.DOI:10.20157/j.cnki.zgsyzz.2025.07.005
山东省猪源和鸡源致泻性大肠埃希菌耐药性特征分析
Analysis of Antimicrobial Resistance Characteristics of Porcine-and Chicken-Derived Diarrheagenic Escherichia coli in Shandong Province
摘要
Abstract
To investigate the antimicrobial resistance characteristics of diarrheagenic Escherichia coli(DEC)in the farming sector of Shandong Province,a total of 120 samples related to pigs and chickens were collected from 35 farms across 10 cities.E.coli strains were isolated,identified using MALDI-TOF mass spectrometry,and classified into pathotypes via multiplex fluorescence quantitative PCR.Antimicrobial susceptibility testing was performed using the broth microdilution method.Whole-genome sequencing was subsequently conducted to analyze genotypic characteristics and phylogenetic relationships.A total of 110 E.coli strains were isolated,including 33 DEC and 77 non-DEC strains.Among the DEC strains,27 were enteroaggregative E.coli(EAEC),4 enterotoxigenic E.coli(ETEC),and 2 enterohemorrhagic E.coli(EHEC).Susceptibility testing showed that DEC strains exhibited high resistance rates to ampicillin(81.82%),florfenicol(81.82%),and chloramphenicol(81.82%).There was no significant difference in resistance rates between DEC and non-DEC strains(P>0.05).However,chicken-derived DEC strains had significantly higher resistance rates to kanamycin,neomycin,cefotaxime,tobramycin,and aztreonam compared to pig-derived DEC strains(P<0.05 or P<0.01).Whole-genome sequencing revealed that the 33 DEC strains belonged to 27 sequence types(STs),with ST10 being the predominant type.A total of 41 resistance plasmid types were identified,among which ColRNAI was the most prevalent.Additionally,54 resistance genes were detected,including those conferring resistance to aminoglycosides(15 types),β-lactams(12),sulfonamides(9),fluoroquinolones(4),amphenicols(4),macrolides(3),tetracyclines(3),phosphonates(2),polypeptides(1),and rifamycins(1).The aminoglycoside resistance gene aph(3')-IIa was significantly more prevalent in DEC strains compared to non-DEC strains,whereas aadA5 was significantly less prevalent(P<0.05).These findings demonstrate that DEC strains derived from pigs and chickens in Shandong Province exhibit severe antimicrobial resistance,harbor diverse resistance plasmids and genes,and display high genetic diversity.The results of this study provide key data to support the optimization of antimicrobial usage policies in animal husbandry and offer a scientific basis for the prevention and control of DEC-associated diarrheal outbreaks and resistance dissemination.关键词
致泻性大肠埃希菌/多重荧光定量PCR/全基因组测序/耐药性Key words
diarrheogenic Escherichia coli/multiplex fluorescence quantitative polymerase chain reaction/whole-genome sequencing/antimicrobial resistance分类
农业科技引用本文复制引用
陈玉,王鹤佳,赵琪,程敏,刘芳琴,崔明全,张纯萍,李霆,张启迪..山东省猪源和鸡源致泻性大肠埃希菌耐药性特征分析[J].中国兽医杂志,2025,61(7):43-55,13.基金项目
国家重点研发计划(2022YFD1800405) （2022YFD1800405）
