Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, and Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture and Rural Affairs, Yangzhou University, Yangzhou 225009, People's Republic of China.
J Food Prot. 2021 Jul 1;84(7):1202-1212. doi: 10.4315/JFP-20-438.
Salmonellosis occurs frequently worldwide, causing serious threats to public health. The abuse of antibiotics is increasing antibiotic resistance in bacteria, thereby making the prevention and control of Salmonella more difficult. A phage can help control the spread of bacteria. In this study, the lytic phage S55, whose host bacterium is Salmonella Pullorum, was isolated from fecal samples obtained from poultry farms. This phage belongs to the Siphoviridae and has a polyhedral head and a retraction-free tail. S55 lysed most cells of Salmonella Pullorum (58 of 60 strains, 96.67%) and Salmonella Enteritidis (97 of 104 strains, 93.27%). One-step growth kinetics revealed that the latent period was 10 min, the burst period was 80 min, and the burst size was 40 PFU per cell. The optimal multiplicity of infection was 0.01, and the phage was able to survive at pH values of 4 to 11 and temperatures of 40 to 60°C for 60 min. Complete genome sequence analysis revealed that the S55 genome consists of 42,781 bp (50.28% GC content) and 58 open reading frames, including 25 frames with known or assumed functions without tRNA genes. S55 does not carry genes that encode virulence or resistance factors. At 4 and 25°C, S55 reduced the populations of Salmonella Pullorum and Salmonella Enteritidis on chicken skin surfaces. S55 may be useful as a biological agent for the prevention and control of Salmonella infections.
沙门氏菌病在世界范围内频繁发生，对公共卫生造成严重威胁。抗生素的滥用正在导致细菌对抗生素的耐药性增加，从而使沙门氏菌的预防和控制更加困难。噬菌体可以帮助控制细菌的传播。在这项研究中，从家禽养殖场的粪便样本中分离出了一种裂解噬菌体 S55，其宿主菌为鸡白痢沙门氏菌。该噬菌体属于长尾噬菌体科，具有多面体头部和无收缩尾。S55 可以裂解大多数鸡白痢沙门氏菌（60 株中的 58 株，96.67%）和肠炎沙门氏菌（104 株中的 97 株，93.27%）的细胞。一步生长动力学研究表明，潜伏期为 10 min，爆发期为 80 min，每个细胞的爆发量为 40 PFU。最佳感染复数为 0.01，噬菌体能在 pH 值为 4 到 11 和温度为 40 到 60°C 的条件下存活 60 min。全基因组序列分析表明，S55 基因组由 42781 bp（50.28%GC 含量）和 58 个开放阅读框组成，其中 25 个框具有已知或假定的功能，没有 tRNA 基因。S55 不携带编码毒力或耐药性因子的基因。在 4°C 和 25°C 下，S55 减少了鸡皮表面鸡白痢沙门氏菌和肠炎沙门氏菌的数量。S55 可能是预防和控制沙门氏菌感染的有用生物制剂。
