中国饲料Issue(17)：60-66,7.DOI:10.15906/j.cnki.cn11-2975/s.2025040056-08
犊牛大肠杆菌噬菌体的分离、生物活性分析及初步应用研究
Isolation,bioactivity analysis and preliminary application studies of bacteriophages against Escherichia coli in calves
摘要
Abstract
In order to screen phages that show a strong lytic effect and a broad host range against bovine Escherichia coli,a strain of E.coli(designated EN8)was isolated from diarrheic calf feces at a cattle farm in Baoding,Hebei Province.Using E.coli EN8 as the host strain,a bacteriophage(vB_EcoM-EN8)was isolated via the double-layer agar plate method.Its morphology was characterized by electron microscopy,and its lytic spectrum,temperature and pH stability,optimal multiplicity of infection(MOI),and growth kinetics were investigated.Preliminary in vitro application studies were also conducted.Results showed that phage vB_EcoM-EN8 had a head-tail structure under electron microscopy,featuring a unique icosahedral head(90 nm in diameter)and a tail(130 nm in length).This classifies it within the order Caudovirales and family Myoviridae.The phage demonstrated broad host specificity,effectively lysing 19 bovine-derived E.coli strains from clinical isolates,7 murine-derived strains,and 1 avian-derived strain,achieving a lytic rate of 27/48(≈56％).In vitro,vB_EcoM-EN8 effectively suppressed E.coli growth across varying MOIs and exhibited tolerance to pH 6.0～10.0 and temperatures of 4～50℃while maintaining high activity.Its optimal MOI was determined as 0.001,with a latent period of 20 min,lytic period of 90 min,and burst size of 422 PFU/cell.Furthermore,vB_EcoM-EN8 demonstrated robust environmental tolerance,stability,and lytic efficiency,providing a technical foundation for developing phage-based therapeutics against calf colibacillosis.关键词
大肠杆菌/犊牛大肠杆菌病/噬菌体/生物学特性/微生态制剂Key words
Escherichia coli/colibacillosis of calves/bacteriophage/biological characteristics/microecologics分类
农业科技引用本文复制引用
高达,马宁,刘嫣然,秦立佳,孙凤莉,李杰峰..犊牛大肠杆菌噬菌体的分离、生物活性分析及初步应用研究[J].中国饲料,2026,(17):60-66,7.基金项目
财政部和农业农村部:国家现代农业产业技术体系(CARS-35) （CARS-35）
河北农业大学大学生创新创业训练计划资助项目(S202510086013) （S202510086013）
