Chen Mianmian, Xu Juntian, Yao Huochun, Lu Chengping, Zhang Wei
College of Veterinary Medicine, Nanjing Agricultural University, Nanjing City, Jiangsu Province, China.
College of Veterinary Medicine, Nanjing Agricultural University, Nanjing City, Jiangsu Province, China.
Gene. 2016 May 10;582(1):47-58. doi: 10.1016/j.gene.2016.01.049. Epub 2016 Jan 29.
Avian pathogenic Escherichia coli (APEC) causes colibacillosis, which results in significant economic losses to the poultry industry worldwide. Due to the drug residues and increased antibiotic resistance caused by antibiotic use, bacteriophages and other alternative therapeutic agents are expected to control APEC infection in poultry. Two APEC phages, named P483 and P694, were isolated from the feces from the farmers market in China. We then studied their biological properties, and carried out high-throughput genome sequencing and homology analyses of these phages. Assembly results of high-throughput sequencing showed that the structures of both P483 and P694 genomes consist of linear and double-stranded DNA. Results of the electron microscopy and homology analysis revealed that both P483 and P694 belong to T7-like virus which is a member of the Podoviridae family of the Caudovirales order. Comparative genomic analysis showed that most of the predicted proteins of these two phages showed strongest sequence similarity to the Enterobacteria phages BA14 and 285P, Erwinia phage FE44, and Kluyvera phage Kvp1; however, some proteins such as gp0.6a, gp1.7 and gp17 showed lower similarity (<85%) with the homologs of other phages in the T7 subgroup. We also found some unique characteristics of P483 and P694, such as the two types of the genes of P694 and no lytic activity of P694 against its host bacteria in liquid medium. Our results serve to further our understanding of phage evolution of T7-like coliphages and provide the potential application of the phages as therapeutic agents for the treatment of diseases.
禽致病性大肠杆菌（APEC）可引发大肠杆菌病，给全球家禽业造成重大经济损失。由于抗生素使用导致的药物残留和抗生素耐药性增加，噬菌体及其他替代治疗剂有望用于控制家禽中的APEC感染。从中国农贸市场的粪便中分离出两种APEC噬菌体，分别命名为P483和P694。随后我们研究了它们的生物学特性，并对这些噬菌体进行了高通量基因组测序和同源性分析。高通量测序的组装结果表明，P483和P694基因组的结构均由线性双链DNA组成。电子显微镜和同源性分析结果显示，P483和P694均属于T7样病毒，是尾病毒目短尾病毒科的成员。比较基因组分析表明，这两种噬菌体的大多数预测蛋白与肠杆菌噬菌体BA14和285P、欧文氏菌噬菌体FE44以及克吕沃氏菌噬菌体Kvp1的序列相似性最强；然而，一些蛋白如gp0.6a、gp1.7和gp17与T7亚组中其他噬菌体的同源物相似性较低（<85%）。我们还发现了P483和P694的一些独特特征，如P694的两种基因类型以及P694在液体培养基中对其宿主细菌无裂解活性。我们的研究结果有助于进一步了解T7样大肠杆菌噬菌体的进化，并为噬菌体作为治疗疾病的治疗剂提供潜在应用。
