食源性大肠杆菌噬菌体的分离及其特性分析

Isolation and characterization of foodborne Escherichia coli phage

中文关键词:  大肠杆菌  噬菌体  生物学特性  生物被膜

英文关键词:Escherichia coli  bacteriophag  biological characteristics  biofilm

中文摘要:

      目的 从污水样品中分离致病性大肠杆菌的烈性噬菌体, 分析其生物学特性, 为食品中致病性大肠杆菌的控制提供参考。方法 以标准菌株Escherichia coli EPEC(CICC10664)为宿主菌, 采用双层平板法, 从扬州市各地污水中分离纯化噬菌体, 通过透射电镜观察其形态、测定最佳感染复数、一步生长曲线、裂解镨及其对宿主菌生物被膜的影响。结果 分离到一株肠致病性大肠杆菌烈性噬菌体, 命名为Ec.P01, 电镜观察其为肌尾噬菌体, 直径约为80 nm, 最佳感染复数为0.01, 一步生长曲线显示其噬菌体Ec.P 01的平均裂解量为48 PFU/mL, 潜伏期约为10 min, 裂解期约为90 min, 热稳定性较好, 对宿主菌生物被膜的形成有明显的抑制作用。结论 本研究分离到一株肠致病性大肠杆菌烈性噬菌体, 为治疗大肠杆菌感染疾病和治理食品及其环境污染提供新的思路与方法。

英文摘要:

      Objective To isolate the Escherichia coli EPEC bacteriophage from the sewage samples and analyze its biological characteristics, so as to provide reference for the control of pathogenic Escherichia coli in food. Methods The phage was isolated and purified from the sewage samples by double-layer agar method. With the host bacterium Escherichia coli EPEC(CICC10664) as standard strain, the purified phage was concentrated negatively stained with uranyl acetate and observed by transmission electron microscopy. Meanwhile, the host range, optimal multiplicity of infection (MOI), one-step growth curve, temperature stability and inhibition of biofilm of the phage were investigated. Results One strain of phage that lysed Escherichia coli EPEC was isolated and named Ec.P01. The electron microscope observation showed that the phage Ec.P01 had an icosahedron head with 80 nm in diameter, and belonged to the family of Myoviridae. The MOI of Ec.P01 was 0.01. One-step growth curve shows that Ec.P01 had a burst size of 48 PFU/mL, the incubation period was about 10 min and the cleavage period was about 90 min. The phage could withstand the temperature up to 70 ℃, and there was a significant inhibitory effect on the formation of biofilm of the host organism. Conclusion The newly isolated phage, which is named Ec.P01, provides new ideas and methods for the treatment of Escherichia coli infection and the treatment of food and its environmental pollution.