某规模化牧场致犊牛腹泻的大肠杆菌分离鉴定及耐药性检测

Isolation,Identification and Drug Resistance Detection of Escherichia coli from Calves Diarrhea in a Large-scale Dairy Farm

[目的]为确定引起石河子某规模化牧场犊牛腹泻的主要病原菌及其耐药情况,并针对犊牛腹泻提出合理应对措施,为该牧场防治犊牛腹泻提供参考。[方法]本研究采取现场流行病学检查,无菌采集15份犊牛腹泻病料,对其进行病原菌分离纯化;通过生化试验以及分子生物学鉴定,确定致犊牛腹泻的病原菌;对病原菌进行药敏试验,确定耐药情况。[结果]经生化试验以及分子生物学鉴定发现,15份犊牛腹泻病料中,有12份分离到了大肠杆菌。药敏试验结果显示,13株大肠杆菌对链霉素耐药率最高为46.15%(6/13),对青霉素、氨苄西林耐药率为38.46%(5/13),且敏感菌株多为中低敏;对四环素敏感性为76.92%(10/13),13株菌株对头孢噻肟和万古霉素敏感性最高,为84.62%(11/13),多数菌株为多重耐药菌株。[结论]本研究针对腹泻犊牛进行病原菌分离鉴定、药敏试验,为该牧场犊牛腹泻诊治提供参考。

[Objective]To determine the main pathogens causing diarrhea in calves and their antibiotic resistance in a large-scale dairy farm in Shihezi area,and to propose reasonable measures against calf diarrhea,providing a reference for the prevention and treatment of calf diarrhea in the farm.[Methods]This study conducted on-site epidemiological examinations,aseptically collected 15 diarrheal samples from calves,and performed pathogen isolation and purification.The pathogens causing calf diarrhea were identified through biochemical tests and molecular biology identification.Antibiotic sensitivity tests were conducted to determine the drug resistance of the pathogens.[Results]Through biochemical tests and molecular biology identification,Escherichia coli was isolated from 12 out of 15 calf diarrhea samples.The antibiotic sensitivity test results showed that the highest resistance rate of 13 E.coli strains was to streptomycin at 46.15%(6/13),followed by penicillin and ampicillin at 38.46%(5/13),with most sensitive strains being moderately or weakly sensitive;the sensitivity to tetracycline was 76.92%(10/13),and the highest sensitivity among the 13 strains was to ceftiofur and vancomycin at 84.62%(11/13),with most strains being multidrugresistant.[Conclusion]This study provides a reference for the diagnosis and treatment of calf diarrhea in the farm by conducting pathogen isolation and identification,and antibiotic sensitivity tests on diarrheal calves.