肺炎克雷伯菌噬菌体vB_KpnP_643的生物学特性及基因组分析

Biological characteristics and genome analysis of phage vB_KpnP_643 of Klebsiella pneumoniae

利用自临床分离的肺炎克雷伯菌从污水中分离得到1株新噬菌体vB_KpnP_643,并对其生物学特性和基因组进行了研究与分析。噬菌体vB_KpnP_643可在涂布有肺炎克雷伯菌平板上呈现出中心透亮且周围有晕环的噬菌斑。电镜观察结果显示,该噬菌体属于短尾病毒科。一步生长曲线表明,噬菌体vB_KpnP_643的潜伏期约3 min,裂解周期约60 min。噬菌体vB_KpnP_643具有较好的热稳定性和酸碱耐受性,可适用于各种环境。此外,基于生物信息学分析,噬菌体vB_KpnP_643基因组全长43331 bp,包含编码64个开放阅读框(ORF),未发现与耐药、毒力及溶原相关的基因,DNA聚合酶的系统发育树分析表明该噬菌体在一个相对独立的分支。本研究结果表明噬菌体vB_KpnP_643有望成为抗击肺炎克雷伯菌感染的一种抗生素替代药物。

In this study,a new bacteriophage vB_KpnP_643 was isolated from sewage using K.pneumoniae and its biological characteristics and genome were studied and analyzed.The bacteriophage vB_KpnP_643 showed central transparent plaque with surrounding halo on a plate coated with K.pneumoniae.Electron microscopy result showed that the phage belonged to the family Podoviridae.The one-step growth curve showed that the incubation period of bacteriophage vB_KpnP_643 was about 3 min and the lysis period was about 60 min.Bacteriophage vB_KpnP_643 has good thermal stability and acid-base tolerance,and can be used in various environments.In addition,based on bioinformatics analysis,the genome length of phage vB_KpnP_643 was 43331 bp,including 64 open reading frames(ORFs),and no genes related to drug resistance,virulence and lysogen were found.Phylogenetic tree analysis of DNA polymerase showed that the phage was in a relatively independent branch.The results of this study indicate that bacteriophage vB_KpnP_643 is expected to be an alternative antibiotic against K.pneumoniae infection.