Zhu Lili, Hou Yanyan, Huang Xi, Wang Shuang, Xie Rui, Yang Jie, Lv Qingjie, Hua Lin, Liang Wan, Peng Zhong, Wu Bin
State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China.
Key Laboratory of Development of Veterinary Diagnostic Products (Ministry of Agriculture), The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, 430070, Hubei, China.
Curr Microbiol. 2022 Jun 9;79(7):216. doi: 10.1007/s00284-022-02908-3.
Shiga toxin-producing Escherichia coli (STEC) O157 is a well-known foodborne pathogen and a leading cause of many intestinal diseases. In this study, we explore the use of a phage cocktail to help control STEC O157 in broth and milk. We isolated three virulent phages from sanitary sewages using a STEC O157 as the indicator bacterium. Phenotypical characterizations revealed that these three phages belong to the Myoviridae family and were stable at different temperatures and pH. They displayed a short latent period between 10 and 20 min, and a burst size (32-65 per infected cell). No virulence factors and drug resistance genes were found in their genomes. Bacterial lysis assays showed that a phage cocktail comprising these three phages was more effective (at least 4.32 log reduction) against STEC O157 at 25 °C with multiplicity of infection (MOI) = 1000 in broth medium. At 4 °C, a 3.8 log reduction in the number of viable STEC O157 after 168-h treatment with phage cocktail at MOI = 1000 was observed in milk, compared to phage-free bacterial control group. Characterizations of phages suggest they could be developed into novel therapeutic agents to control STEC O157 in milk production.
产志贺毒素大肠杆菌（STEC）O157是一种知名的食源性病原体，也是许多肠道疾病的主要病因。在本研究中，我们探索使用噬菌体鸡尾酒来帮助控制肉汤和牛奶中的STEC O157。我们以STEC O157作为指示菌，从生活污水中分离出三种烈性噬菌体。表型特征表明，这三种噬菌体属于肌尾噬菌体科，在不同温度和pH值下均稳定。它们的潜伏期较短，在10到20分钟之间，裂解量为每个感染细胞产生32 - 65个噬菌体。在它们的基因组中未发现毒力因子和耐药基因。细菌裂解试验表明，在肉汤培养基中，当感染复数（MOI）= 1000时，由这三种噬菌体组成的噬菌体鸡尾酒在25°C下对STEC O157更有效（至少减少4.32个对数级）。在4°C下，与无噬菌体的细菌对照组相比，用MOI = 1000的噬菌体鸡尾酒处理168小时后，牛奶中STEC O157的活菌数减少了3.8个对数级。噬菌体的特性表明它们可以被开发成新型治疗剂，用于控制牛奶生产中的STEC O157。
