摘要
【目的】探究大肠杆菌噬菌体vB_EcoP_GN07的生物学特性和全基因组特征,为开发噬菌体“鸡尾酒”制剂防治致病性大肠杆菌病提供生物学材料。【方法】采用双层平板法从广西南宁某养鸡场分离到1株大肠杆菌裂解性噬菌体vB_EcoP_GN07;通过透射电镜观察、宿主谱测定、pH和温度稳定性评估、最佳感染复数(MOI)测定、一步生长曲线测定、全基因组测序等方法了解噬菌体的形态学、生物学特性和全基因组特性。【结果】透射电镜显示,vB_EcoP_GN07头部直径为45 nm±5 nm,尾部长约25 nm,属于短尾噬菌体科,宿主特异性强;在4~60℃可以保持效价稳定,在pH 3.0~11.0可以保持噬菌体活性;该噬菌体的最佳MOI为10-2;一步生长曲线显示该噬菌体潜伏期为60 min,裂解量为560 PFU/cell;测序结果显示其属于双链线型DNA,长度为70120 bp,GC含量为42.8%;噬菌体vB_EcoP_GN07共有81个开放阅读框,其中23个为已知功能蛋白。经BLASTN比对显示,vB_EcoP_GN07与NCBI数据库中其他噬菌体相似性较低,符合N4-like属噬菌体的特点,没有发现与耐药性、毒力因子、毒素和溶源性相关蛋白。【结论】试验成功分离到1株大肠杆菌噬菌体vB_EcoP_GN07,其具有裂解能力强、特异性强、耐酸碱的特点,与其他噬菌体相似性较低,为1株新的N4-like噬菌体。结果可为未来应用大肠杆菌噬菌体vB_EcoP_GN07开发新型杀菌剂提供理论依据。
【Objective】This study was aimed to explore the biological and genome characteristics of Escherichia coli(E.coli)phage vB_EcoP_GN07,and provide biological materials for the development of phage cocktail formulations against pathogenic E.coli disease.【Method】A strain of E.coli lytic phage vB_EcoP_GN07 was isolated from a chicken farm in Nanning,Guangxi using the double-layer plate method.Transmission electron microscope observation,host spectrum determination,pH and temperature stability evaluation,the optimal multiplicity of infection(MOI)determination,one-step growth curve determination and whole genome sequencing were used to understand the morphology,biological characteristics and genome-wide characteristics of the phage.【Result】Transmission electron microscopy showed vB_EcoP_GN07 had a head diameter of about 45 nm±5 nm and tail length of about 25 nm,belonging to the Podoviridae.which had strong host specificity.The phage titer could be kept stable at 4 to 60℃,and the phage activity could be maintained at pH 3.0-11.0.The optimal MOI of the phage was 10-2.The one-step growth curve showed that the incubation period of the phage was 60 min,and the burst size was 560 PFU/cell.Sequencing results showed that it belonged to double stranded DNA,with a length of 70120 bp and a GC content of 42.8%.The phage vB_EcoP_GN07 had 81 open reading frames,of which 23 were known functional proteins.BLASTN comparison showed that the phage vB_EcoP_GN07 had low similarity with other phages in NCBI database,conformed to the characteristics of N4-like phage,and lacked virulence genes and drug resistance genes associated with antibiotic resistance,toxins and virulence factors.【Conclusion】An E.coli phage vB_EcoP_GN07 was successfully isolated in this study,which had strong cracking ability,host specificity and acid and alkali resistance.vB_EcoP_GN07 was less similar to other phages,and determined to be a new N4-like phage.This results provided a theoretical basis for the development of new fungicides with application E.coli phage vB_EcoP_GN07.
作者
王乐平
潘艳
谭奕舟
李磊
韩凯欧
曹雅洁
李军
周雨晴
廖玉英
马东鑫
龚俞
彭昊
王晓晔
WANG Leping;PAN Yan;TAN Yizhou;LI Lei;HAN Kaiou;CAO Yajie;LI Jun;ZHOU Yuqing;LIAO Yuying;MA Dongxin;GONG Yu;PENG Hao;WANG Xiaoye(Institute of Animal Science and Technology,Guangxi University,Nanning 530004,China;Guangxi Veterinary Research Institute,Nanning 530001,China;Guizhou Provincial Livestock and Poultry Genetic Resources Management Station,Guiyang 550001,China;Guangxi Agricultural Vocational University,Nanning 530009,China)
出处
《中国畜牧兽医》
CAS
CSCD
北大核心
2023年第4期1522-1531,共10页
China Animal Husbandry & Veterinary Medicine
基金
广西重点研发计划(AB21238003、AB19245010)
国家水禽产业技术体系建设专项(CARS-42)
广西牛羊产业创新团队建设项目(nycytxgxcxtd-2021-09)
南宁市重点研发计划(20212023)。
关键词
大肠杆菌
噬菌体
生物学特性
全基因组分析
比较基因组学
Escherichia coli
phage
biological characteristics
whole genome analysis
comparative genomics
