禽致病性大肠杆菌(APEC),如O1、O2和O78,是与鸡健康有关的重要血清群,负责大肠杆菌病。在这项研究中,我们从艾伯塔省的母鸡粪便和人类污水中分离并鉴定了噬菌体(噬菌体),具有控制蛋鸡大肠杆菌病的潜力。裂解液的轮廓,主机范围,七个APEC感染噬菌体的pH耐受性和形态(ASO1A,ASO1B,ASO2A,ASO78A,ASO2B,使用微孔板噬菌体毒力测定和透射电子显微镜(TEM)评估AVIO78A和ASO78B)。使用AMRFinderPlus和毒力因子数据库预测基因组水平上噬菌体的潜在安全性。最后,使用病毒基因组间距离计算器和基于单基因的系统发育树推断噬菌体属和与NCBIGenBank数据库中其他已知噬菌体的遗传相关性。在这项研究中,七个感染APEC的噬菌体优先裂解APEC菌株,ECL21443(O2)最容易受到噬菌体的影响(n=5)。ASO78A拥有最广泛的主机范围,裂解除ECL20885(O1)外的所有测试菌株(n=5)。孵育4小时后,噬菌体在pH为2.5或3.5-9.0时存活。基于TEM,噬菌体被归类为肌病毒,syphovirus和podovirus.没有与毒力相关的基因,在噬菌体基因组中检测到抗菌素抗性或溶源性。比较基因组分析在五个属中放置了七个噬菌体中的六个:费利克乌纳病毒(ASO1A和ASO1B),斑驳病毒(ASO2A),Tequatrovirus(ASO78A),Kayfunavirus(ASO2B)和Sashavirus(AVIO78A)。基于核苷酸基因组间相似性(<70%),噬菌体ASO78B未被指定为syphovirus属,可以代表Caudoviricetes类中的新属。尾纤维蛋白系统发育揭示了感染APEC的噬菌体和密切相关的噬菌体内部的变化。环境中存在的各种感染APEC的噬菌体证明了控制家禽大肠杆菌病的潜力。
Avian pathogenic Escherichia coli (APEC), such as O1, O2 and O78, are important serogroups relating to chicken health, being responsible for colibacillosis. In this study, we isolated and characterized bacteriophages (phages) from hen feces and human sewage in Alberta with the potential for controlling colibacillosis in laying hens. The lytic profile, host range, pH tolerance and morphology of seven APEC-infecting phages (ASO1A, ASO1B, ASO2A, ASO78A, ASO2B, AVIO78A and ASO78B) were assessed using a microplate phage virulence assay and transmission electron microscopy (TEM). The potential safety of phages at the genome level was predicted using AMRFinderPlus and the Virulence Factor Database. Finally, phage genera and genetic relatedness with other known phages from the NCBI GenBank database were inferred using the virus intergenomic distance calculator and single gene-based phylogenetic trees. The seven APEC-infecting phages preferentially lysed APEC strains in this study, with ECL21443 (O2) being the most susceptible to phages (n = 5). ASO78A had the broadest host range, lysing all tested strains (n = 5) except ECL20885 (O1). Phages were viable at a pH of 2.5 or 3.5-9.0 after 4 h of incubation. Based on TEM, phages were classed as myovirus, siphovirus and podovirus. No genes associated with virulence, antimicrobial resistance or lysogeny were detected in phage genomes. Comparative genomic analysis placed six of the seven phages in five genera: Felixounavirus (ASO1A and ASO1B), Phapecoctavirus (ASO2A), Tequatrovirus (ASO78A), Kayfunavirus (ASO2B) and Sashavirus (AVIO78A). Based on the nucleotide intergenomic similarity (<70%), phage ASO78B was not assigned a genus in the siphovirus and could represent a new genus in class Caudoviricetes. The tail fiber protein phylogeny revealed variations within APEC-infecting phages and closely related phages. Diverse APEC-infecting phages harbored in the environment demonstrate the potential to control colibacillosis in poultry.