Li Pei, Wang Hui, Li Min, Qi Weiling, Qi Zitai, Chen Weiye, Dong Yongyi, Xu Zhengjun, Zhang Wei
College of Veterinary Medicine, Nanjing Agricultural University, No.1 Weigang, Xuanwu District Nanjing City 210095, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, No.1 Weigang, Xuanwu District Nanjing City 210095, China; OIE Reference Lab for Swine Streptococcosis, No.1 Weigang, Xuanwu District Nanjing City 210095, China; MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, No.1 Weigang, Xuanwu District Nanjing City 210095, China.
Jiangsu Animal Disease Control Center, 124 Caochangmen street, Gulou District, Nanjing 210036, China.
Virus Res. 2022 Jan 15;308:198628. doi: 10.1016/j.virusres.2021.198628. Epub 2021 Nov 13.
The increase of multi-drug resistant and multi-serotypes of pathogenic Escherichia coli has brought more severe challenge to control infection. Nowadays, bacteriophage is a promising tool to treat colibacillosis as an alternative of antibiotics. A coliphage P479, isolated from sewage of poultry farm, could lyse multiple serotypes, including not only O1, O2, O8, O9, O21, O78, O83, O145 of Avian pathogenic E. coli, but O157:H7 of Enterohaemorrhagic E. coli and O18:K1:H7 Neonatal meningitis E. coli. Additionally, P479 could also lyse multi-drug resistant E. coli. These indicated that P479 had good lytic ability. One-step growth curve revealed that the latent time period of P479 was 10 min and the burst size was about 318 PFU/cell. Stability tests demonstrated that P479 had good stability under various temperature (4 to 50 °C) and pH (3 to11) conditions. P479 contained of a linear, double-stranded DNA molecule of 172,033 bp with 40.3% GC content. P479 contained 296 putative coding sequences (CDSs) and two tRNA genes. Based on genomic comparison, P479 was classified as a member of genus Gaprivervirus, subfamily Tevenvirinae, family Myoviridae, order Caudovirales. No known virulent or lysogenic genes were detected in the genome of P479, manifesting P479 was safe to adhibit. Antibacterial activity in vitro manifested that P479 has varying degrees bacteriostatic activity against different bacteria. According to the above properties, P479 has the potential to be applied in phage therapy in the future.
致病性大肠杆菌多重耐药性和多种血清型的增加给控制感染带来了更严峻的挑战。如今，噬菌体作为抗生素的替代品，是治疗大肠杆菌病的一种有前景的工具。从家禽养殖场污水中分离出的一株大肠杆菌噬菌体P479，能够裂解多种血清型的细菌，不仅包括禽致病性大肠杆菌的O1、O2、O8、O9、O21、O78、O83、O145血清型，还包括肠出血性大肠杆菌的O157:H7血清型和新生儿脑膜炎大肠杆菌的O18:K1:H7血清型。此外，P479还能裂解多重耐药性大肠杆菌。这些表明P479具有良好的裂解能力。一步生长曲线显示，P479的潜伏期为10分钟，裂解量约为318个噬菌斑形成单位/细胞。稳定性测试表明，P479在各种温度（4至50°C）和pH（3至11）条件下都具有良好的稳定性。P479含有一个172,033 bp的线性双链DNA分子，GC含量为40.3%。P479含有296个推定的编码序列（CDS）和两个tRNA基因。基于基因组比较，P479被归类为肌尾噬菌体目、肌病毒科、Tevenvirinae亚科、Gaprivervirus属的成员。在P479的基因组中未检测到已知的毒性或溶原性基因，表明P479使用安全。体外抗菌活性表明，P479对不同细菌具有不同程度的抑菌活性。根据上述特性，P479未来有潜力应用于噬菌体治疗。
