A lytic phage to control multidrug-resistant avian pathogenic Escherichia coli (APEC) infection

• DOI: 10.3389/fcimb.2023.1253815
• Publication Date: 2023-09-07T20:51:40Z
• Authors: Lan Yao; Yinli Bao; Jiangang Hu; Beibei Zhang; Zhiyang Wang; Xinyu Wang; Weiqi Guo; Di Wang; Jingjing Qi; Mingxing Tian; Yanqing Bao; Haihua Li; Shaohui Wang
• Keywords: Lytic cycle; Multiplicity of infection; Phage therapy; Pathogenic Escherichia coli

The inappropriate use of antibiotics has led to the emergence multidrug-resistant strains. Bacteriophages (phages) have gained renewed attention as promising alternatives or supplements antibiotics. In this study, a lytic avian pathogenic Escherichia coli (APEC) phage designated PEC9 was isolated and purified from chicken farm feces samples. morphology, genomic information, optimal multiplicity infection (MOI), one-step growth curve, thermal stability, pH in vitro antibacterial ability biofilm formation inhibition were determined. Subsequently, therapeutic effects phages investigated mice model. results showed that member siphovirus-like by electron microscopy observation. Biological characterization revealed it could lyse two serotypes E. coli, including O1 (9/20) O2 (6/20). (MOI) 0.1. Phage had latent period 20 min burst 40 min, with an average size 68 plaque-forming units (PFUs)/cell. It maintained good activity at 3-11 4-50°C efficiently inhibit bacterial planktonic cell formation, reduce counts within biofilm, when MOI 0.01, 0.1, 1, respectively. Whole-genome sequencing dsDNA virus genome 44379 bp GC content 54.39%. contains 56 putative ORFs no toxin, virulence, resistance-related genes detected. Phylogenetic tree analysis is closely related vB_EcoS_Zar3M, vB_EcoS_PTXU06, SECphi18, ZCEC10, ZCEC11, but most these exhibit different gene arrangement. successfully protect against APEC infection, improved survival rate, reduced loads, organ lesions. To conclude, our suggest may be candidate can used alternative control infection.