一株分离自医院污水的宽裂解谱铜绿假单胞菌噬菌体的生物学特性及基因分析

Biological characteristics and genetic analysis of a strain of Pseudomonas aeruginosa phage isolated from hospital sewage

目的分析1株从医院污水中分离的宽裂解谱铜绿假单胞菌噬菌体的基因组信息,了解其生物学特性,为铜绿假单胞菌院内感染的治疗提供新的思路。方法收集医院污水标本,采用双层平板法进行噬菌体分离纯化,用电镜观察其形态,测定噬菌体裂解谱、最佳感染复数(MOI)和一步生长曲线;对噬菌体进行全基因组测序分析。结果从污水标本中分离纯化获得1株铜绿假单胞菌噬菌体YFY1,MOI指数为0.1,一步生长曲线显示潜伏期约为50 min,爆发期约为40 min;电镜观察其头部长约63 nm,尾长约10 nm,为尾部呈短棒状的肌尾噬菌体。YFY1基因长度为61404 bp,GC含量为60.18%,其基因组注释共得到84个开放阅读框架(ORF),在注释的107个相似蛋白中有81个蛋白相似度>50%,其中64个为假设蛋白,17个为体现噬菌体功能和结构的重要蛋白。结论YFY1是一株烈性肌尾噬菌体,该噬菌体具有多种与功能相关的蛋白,可为铜绿假单胞菌感染的生物治疗提供理论依据。

Objective To analyze the genomic information on a phage with a broad lytic spectrum against Pseudomonas aeruginosa isolated from hospital sewage,to ascertain its biological characteristics,and to provide new ideas for the treatment of nosocomial infections with P.aeruginosa.Methods Sewage samples were collected from the Hospital,and the phage was isolated and purified using the double-layer agar plate method.Morphology was observed under an electron microscope.The lysis profile,optimal multiplicity of infection(MOI),and one-step growth curve were determined,and then the biological characteristics of the phage were analyzed.Results YFY1,a phage of P.aeruginosa,was obtained from sewage samples,its MOI was 0.1,and its one-step growth curve indicated that the latent period was about 50 min,and the burst period was about 40 min.The head length was about 63 nm,and the tail length was about 10 nm.The phage is a short rod-shaped phage with a contractile tail according to electron microscopy.The YFY1 gene was 61404 bp in length,and its GC content was 60.18%.A total of 84 open reading frameworks(ORF)were obtained for genome annotation.Of 107 similar annotated proteins,81 proteins had a similarity>50%,64 of which were hypothetical proteins,and 17 were important proteins reflecting the function and structure of the phage.Conclusion YFY1 is a lytic Myoviridae phage,and the phage has a variety of proteins related to its function.These findings can provide a theoretical basis for understanding the biological characteristics of the phage.