中国兽医杂志2023，Vol.59Issue(12)：11-19,9.
鸡源大肠杆菌噬菌体LHE71的生物学特性和全基因组序列分析
Biological Characteristics and Whole Genome Sequence Analysis of Chicken-Origin Escherichia coli Phage LHE71
摘要
Abstract
In order to obtain a phage with highly efficient and broad-spectrum lytic features,this study used 96 clinical isolates of chicken-origin Escherichia coli(E.coli)as host bacteria.Phages were isolated and purified from 5 fecal samples collected from chicken farms using the double-layer agar plate method.The phage's lytic spectrum was determined,and the isolated phages were subjected to morphological observation,biological characteristic determination,and whole genome sequence analysis.The results showed that one virulent E.coli phage was isolated from the chicken fecal sample,named LHE71,which formed clear plaques with halos on bacterial lawns.Transmission electron microscopy revealed that the phage had a long-tailed morphology,with a head diame-ter of about 70 nm and a curved tail of about 150 nm in length.The phage proliferated in the presence of E.coli K12 as the host bac-terium,with the highest efficacy observed when the infection multiplicity was 0.1,reaching a titer of 2.6 × 1015 PFU/mL.The latent period of phage LHE71 proliferation was approximately 40 min,and the burst size was about 104 PFU/cell.Phage LHE71 exhibited stability in activity at temperatures below 60℃ and within a pH range of 7 to 9,and it also demonstrated some resistance to ultraviolet light.The whole genome length of phage LHE71 was 50 158 bp,with 81 predicted open reading frames(ORFs),of which 24 enco-ded known functional proteins.The phage lacked tRNA and did not contain virulence or antibiotic resistance genes.In the GenBank database,there were 32 phages with homology to LHE71.Evolutionary analysis based on major capsid proteins and terminase large subunits revealed that LHE71 belonged to the Tunavirus genus.These results demonstrate the successful isolation and identification of a highly efficient and broad-spectrum lytic phage,LHE71,from chicken fecal samples,which exhibited promising biological charac-teristics.This study provides a foundation for further development of phage formulations for controlling chicken-origin E.coli-associ-ated diseases.关键词
大肠杆菌/噬菌体/生物学特性/基因组分析Key words
Escherichia coli/phage/biological characteristics/genome analysis分类
农业科技引用本文复制引用
荣家庆,任慧英,刘文华,张灿..鸡源大肠杆菌噬菌体LHE71的生物学特性和全基因组序列分析[J].中国兽医杂志,2023,59(12):11-19,9.基金项目
山东省自然基金面上项目(ZR2021MC053) （ZR2021MC053）
山东省现代农业产业技术体系家禽创新团队建设项目(SIAIT-11-03) （SIAIT-11-03）
青岛农业大学研究生创新计划(QNYCN22005) （QNYCN22005）
