摘要 旨在为鸡大肠埃希氏菌病防治提供噬菌体材料。使用双层琼脂平板法从鸡场污水中分离纯化得到1株鸡埃希氏菌裂解性噬菌体vB-EcoM-IME540(IME540),并通过噬菌斑、透射电镜观察该噬菌体的噬菌斑和形态特征,测定其最佳感染复数、耐热稳定性、pH敏感性等生物学特性,并对其进行全基因组测序及进化分析。结果表明,噬菌体vB-EcoM-IME540的噬菌斑呈透亮的圆形,直径0.8 mm~1.1 mm,边缘整齐无晕环,裂解谱较窄(3/45);透射电镜下其头部呈椭圆形且具有收缩尾与尾丝,头尾被颈圈分开,头大小约106.7 nm×73.3 nm,尾长约140 nm×16.7 nm;全基因组大小为170237 bp,G+C为39.46%;基因序列与大肠埃希氏菌噬菌体Bp7的相似性为97.44%;最佳MOI=0.000001,潜伏期约为20 min,暴发时长约为130 min,裂解量约为23 PFU/cell;在80℃条件下20 min活性全部丧失;在pH为4.0~13.0内均有很高的活性。说明噬菌体vB-EcoM-IME540是一株具有一定耐热、耐酸碱能力的肌尾科的大肠埃希氏菌裂解性噬菌体。 In order to provide lytic bacteriophage for the prevention and treatment of chicken colibacillosis,in this experiment,a strain of lytic bacteriophage infecting chicken Escherichia coli,named vB-EcoM-IME540(IME540)was isolated and purified from chicken farm sewage by double-layer agar plate method.The morphological characteristics of the phage were studied by plaque and transmission electron microscopy.The biological characteristics such as optimal multiplicity of infection(MOI),heat-resistant stability and pH sensitivity were determined,and genome sequencing and evolution analysis were performed.The results showed that the bacteriophage vB-EcoM-IME540 could crack the host bacteria.The plaques of the phage were translucent and round,with a diameter of 0.8 mm-1.1 mm,the edges were neat and halo-free,and the host rang was narrow(3/45).The head was observed under transmission electron microscopy oval with approximately 106.7 nm×73.3 nm,the tail is contractile with approximately 140 nm×16.7 nm.The whole genome size is 170237 bp,G+C is 39.46%;the homology of amino acid sequence of phage Enterobacteria phage Bp7 was 97.44%;the optimal MOI=0.000001,the incubation period is about 20 min,the burst time is about 130 min,the lysis amount is about 23 PFU/cell,the titer of vB-EcoM-IME540 was lost at 80°C for 20 min,and keep high in pH=4.0-13.0.In summary,phage vB-EcoM-IME540 was a Myoviridae lytic Escherichia coli phage with a certain heat tolerance and acid and alkali resistance.
出处 《动物医学进展》 北大核心 2021年第5期30-35,共6页 Progress In Veterinary Medicine
基金 新疆生产建设兵团重点领域科技攻关项目(2013BA002) 八师石河子市促进科技成果转化引导计划项目(2019ZH05) 石河子大学成果转化与技术推广计划项目(CGZH201908)。
