Characterizing lytic bacteriophages against pathogenic E. coli: killing spectrum, efficacy in vivo, and genomic analysis

对动物健康和食品安全具有重要意义的细菌性病原体对农业和食品工业具有重大的全球性影响。细菌对抗菌素的耐药性有所增加，由于抗菌素耐药性可能增加，在牲畜和家禽中使用抗生素受到质疑。因此，需要采取其他策略来应对食品生产链中的细菌性病原体。溶解性噬菌体（噬菌体）是细菌特异性的病毒，可以溶解并杀死它们的目标细菌。SyntBioLab Inc.的重点之一是开发利用噬菌体控制细菌病原体的应用程序。大肠杆菌是食品安全和动物健康的主要问题。特别是，在家禽（鸡和火鸡）中，禽致病性大肠杆菌（APEC）是呼吸道和全身感染的主要原因。有许多类型的大肠杆菌菌株感染家禽，因此，彻底表征具有广谱活性的噬菌体是一项挑战**。在** NSERC参与资助期间，我们从环境样品中分离出裂解噬菌体。我们证明了某些噬菌体对多种APEC菌株具有广泛的杀伤活性。本提案的目的是通过确定接种特定APEC菌株的雏鸡**减少定植的功效来继续对这些噬菌体进行表征。我们还计划通过基因组测序、比较基因组学和电子显微镜进一步表征这些噬菌体。该项目将与合作伙伴SyntBioLab Inc.密切合作，结合我们集团在致病性大肠杆菌和鸡**实验模型方面的专业知识，以及SyntBioLab Inc.的优势，包括比较基因组学和**生物信息学。该项目的总体目的是建立最强大和有效的噬菌体，并可以减少许多不同APEC菌株的定植。减少粪便中大肠杆菌的数量将降低由粪便和垃圾引起的呼吸道大肠杆菌病的风险。这种噬菌体可以减少APEC感染，提高家禽产量，减少抗生素的使用来治疗这种感染。

Bacterial pathogens of importance to animal health and food safety have major and global impacts on**agriculture and food industries. There has been an increase in bacterial resistance to antimicrobials, and**antibiotic use in livestock and poultry has been questioned due to likelihood of increased antimicrobial**resistance. Alternative strategies to contend with bacterial pathogens within the food production chain are**therefore needed. Lytic bacteriophages (phages) are bacteria-specific viruses that can lyse and kill their**bacterial targets. One of the focuses of SyntBioLab Inc. is to develop applications to control bacterial**pathogens by using phages. Escherichia coli is a major problem for food safety and animal health. In particular,**in poultry (chickens and turkeys), avian pathogenic E. coli (APEC) is the predominant cause of respiratory and**systemic infection. There are numerous types of E. coli strains that infect poultry, and it is therefore a challenge**to thoroughly characterize phages that will have broad-spectrum activity against a diversity of APEC. During**the NSERC Engage grant, we isolated lytic phages from environmental samples. We demonstrated that certain**phages have a broad killing activity against a variety of APEC strains. The purpose of this proposal is to**continue characterization of these phages by determining efficacy to reduce colonization of young chicks**inoculated with specific APEC strains. We also plan on further characterizing these bacteriophages by genome**sequencing and comparative genomics and electron microscopy. This project will be in close collaboration**with the partner, SyntBioLab Inc., by combining our group's expertise in pathogenic E. coli and chicken**experimental models and the strengths of SyntBioLab Inc., including comparative genomics and**bioinformatics. The overall purpose of the project is to establish the most robust and effective phages and can**reduce colonization of a number of different APEC strains. Reduced numbers of E. coli from feces would**lower the risk of respiratory colibacillosis originating from feces and litter dust. Such bacteriophages could**reduce APEC infections, improve poultry production, and decrease antibiotic usage to treat such infections.