College of Veterinary medicine, Qingdao Agricultural University, Qingdao, Shandong, China.
Qingdao Phagepharm Bio-tech Co, Ltd, Qingdao, Shandong, China.
Virus Res. 2022 Nov;321:198913. doi: 10.1016/j.virusres.2022.198913. Epub 2022 Sep 5.
A lytic bacteriophage vB_EcoM_DE7 (hereafter designated DE7) that could infect donkey-derived Escherichia coli was isolated. The bacteriophage was examined by transmission electron microscopy, and the result showed that DE7 belonged to the family Myoviridae. The microbiological characterization revealed that DE7 was stable over a broad range of pHs (3 ∼10) at 40-50 °C. The latent period was 10 min, and the burst size was 43 PFUs/infected cell. The whole-genome sequencing showed that DE7 was a dsDNA virus and had a genome of 86,130 bp. The genome contained 124 predicted open reading frames (ORFs), 35 of which had known functions, including DNA replication and modification, transcriptional regulation, structural and packaging proteins, and host cell lysis. Twenty tRNA genes were identified, but no genes associated with bacterial pathogenicity, lysogeny and drug resistance were identified. BLASTN analysis revealed that phage DE7 had a high sequence identity (96%) with Salmonella phage vB_SPuM_SP116, but it could not lyse any Salmonella strain tested in this study. DE7 was classified as a Felix O1-like virus based on its general characterization and genomic information. Since phage DE7 exhibited high efficacy in lysing E. coli and lacked genes associated with bacterial virulence, antimicrobial resistance and lysogeny, it could be potentially used to control foal diarrhoea caused by E. coli.
分离到一株可感染驴源大肠杆菌的裂解性噬菌体 vB_EcoM_DE7（以下简称 DE7）。透射电子显微镜观察结果表明，DE7 属于肌尾噬菌体科。微生物学特性研究表明，DE7 在 pH3∼10、40∼50℃的较宽范围内稳定。潜伏期为 10min，爆发量为 43PFUs/感染细胞。全基因组测序显示，DE7 是一种 dsDNA 病毒，基因组大小为 86130bp。基因组包含 124 个预测的开放阅读框（ORFs），其中 35 个具有已知功能，包括 DNA 复制和修饰、转录调控、结构和包装蛋白以及宿主细胞裂解。鉴定出 20 个 tRNA 基因，但未鉴定出与细菌致病性、溶原性和耐药性相关的基因。BLASTN 分析显示，噬菌体 DE7 与 Salmonella 噬菌体 vB_SPuM_SP116 的序列高度同源（96%），但不能裂解本研究中测试的任何 Salmonella 菌株。根据其一般特征和基因组信息，将 DE7 归类为 Felix O1 样病毒。由于 DE7 对大肠杆菌具有高效的裂解作用，且缺乏与细菌毒力、抗药性和溶原性相关的基因，因此它可能被用于控制由大肠杆菌引起的驹腹泻。
