College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.
Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China.
Virus Genes. 2022 Oct;58(5):436-447. doi: 10.1007/s11262-022-01915-7. Epub 2022 Jun 16.
Multiple pathogenic types or serotypes restrict treatment for colibacillosis. In addition, rising antibiotic resistance has heightened public awareness to prevent and control pathogenic Escherichia coli. The bacteriophage is a viable technique to treat colibacillosis as an alternative to antibiotics. P762, a coliphage isolated from duck farm sewage, was demonstrated to cloud lyse Shiga toxin-producing Escherichia Coli serotypes O157 and non-O157 (17/39), Avian pathogenic E. coli covered serotype O78, O83, and O9 (5/19), and other pathogenic Escherichia coli (5/17). Additional fundamental biological characteristics analysis revealed that P762 is stable at pH 3 ~ 11 and temperature between 4 °C and 60 °C, and its optimum multiplicity of infection (MOI) is 0.1. The one-step curve of P762 exhibited three bursts of growth stage: two rapid and one slow stage. Furthermore, the first rapid burst size is 80 CFU/PFU, the burst size of the slow stage is 10 CFU/PFU, and the second rapid burst size is about 990 CFU/PFU. In addition, P762 can form a "halo" on a double agar plate, implying that the phage secretes depolymerase. With 95.14% identity and 90% query coverage, genome sequence analysis revealed that P762 is most closely related to Escherichia phage DY1, which belongs to the genus Kayfunavirus. After screening using RAST and VFDB, no virulence factors were discovered in P762. In vitro antibacterial tests revealed that P762 has high bactericidal activity in lettuce leaves contaminated with STEC. In conclusion, phage P762 might be employed in the future to prevent and control pathogenic Escherichia coli.
多种病原体类型或血清型限制了大肠杆菌病的治疗。此外，抗生素耐药性的上升提高了公众对预防和控制致病性大肠杆菌的认识。噬菌体是治疗大肠杆菌病的一种可行技术，可以替代抗生素。从鸭场污水中分离出的噬菌体 P762 被证明可以使产志贺毒素大肠杆菌血清型 O157 和非 O157（17/39）、禽致病性大肠杆菌涵盖的血清型 O78、O83 和 O9（5/19）以及其他致病性大肠杆菌（5/17）云雾状裂解。进一步的基础生物学特性分析表明，P762 在 pH 值 3 到 11 和 4°C 到 60°C 之间的温度下稳定，其最佳感染复数（MOI）为 0.1。P762 的一步生长曲线显示出三个生长阶段的爆发：两个快速阶段和一个缓慢阶段。此外，第一个快速爆发大小为 80 CFU/PFU，缓慢阶段的爆发大小为 10 CFU/PFU，第二个快速爆发大小约为 990 CFU/PFU。此外，P762 可以在双层琼脂平板上形成“晕圈”，这表明噬菌体分泌解聚酶。基因组序列分析显示，与 Escherichia 噬菌体 DY1 的同源性最高，达到 95.14%，查询覆盖率为 90%，属于 Kayfunavirus 属。经 RAST 和 VFDB 筛选，P762 中未发现毒力因子。体外抗菌试验表明，P762 对生菜叶中污染的 STEC 具有很高的杀菌活性。综上所述，噬菌体 P762 可能在未来用于预防和控制致病性大肠杆菌。
