China Animal Husbandry & Veterinary Medicine ›› 2025, Vol. 52 ›› Issue (11): 5476-5487.doi: 10.16431/j.cnki.1671-7236.2025.11.042

• Basic Veterinary Medicine • Previous Articles    

Isolation,Identification and Whole Genome Analysis of a Bovine Carbapenem-resistant Klebsiella pneumoniae Phage

PANG Shuqi1,2, HAN Zhenghui3, TANG Kunping1,2, WANG Leping2, LI Chunling1,2, BAI Huili2, LI Changting2, LI Xian4, YIN Yangyan2, MA Chunxia2, TENG Ling2, LI Jun2, CHEN Zhongwei2, ZHOU Yilin5, PENG Hao2   

  1. 1. College of Animal Science and Technology, Guangxi University, Nanning 530004, China;
    2. Guangxi Veterinary Research Institute, Nanning 530001, China;
    3. Guangxi Academy of Forestry, Nanning 530002, China;
    4. Guangxi Agricultural Engineering Vocational and Technical College, Chongzuo 532100, China;
    5. Guangxi Nanning Arboretum, Nanning 530000, China
  • Received:2025-01-16 Published:2025-10-30

Abstract: 【Objective】 Using the bovine-derived carbapenem-resistant Klebsiella pneumoniae clinical isolate KLB-04 (K57 type) as the host strain,this study aimed to isolate a highly lytic phage targeting this bacterium and analyze its biochemical characteristics and whole genome,so as to provide a scientific basis for the clinical application of Klebsiella pneumoniae phages and the development of phage-derived proteins. 【Method】 The lytic phage was isolated from sewage using the double-layer agar method.Transmission electron microscopy,host range analysis,pH tolerance and temperature stability tests,determination of the optimal multiplicity of infection,one-step growth curve assay,and whole-genome sequencing were employed to investigate the morphological,biological,and genomic characteristics of the isolated phage. 【Result】 A lytic bacteriophage strain was isolated and designated as GXKP01.GXKP01 formed plaques with an average diameter of approximately 3 mm,surrounded by a halo measuring about 2 mm in width.Transmission electron microscopy revealed that GXKP01 possessed a head-tail structure,with the head being a regular icosahedron approximately 60 nm in diameter and the tail measuring between 15-20 nm in length,which belonged to the subfamily Studiervirinae and the genus Przondovirus.The latent period of GXKP01 infection in KLB-04 was approximately 10 min,with a complete infection cycle lasting around 70 min.Each infected bacterium produced approximately 136 progeny phage particles.Phage GXKP01 could only cleave the host bacterium KLB-04,with strong specificity.Additionally,GXKP01 demonstrated remarkable stability across a wide range of temperatures (4-60 ℃) and pH levels (pH 3.0-12.0).Genomic analysis revealed that GXKP01’s genome consisted of double-stranded linear DNA with a length of 39 795 bp,a GC content of 53.13%,and contained 44 coding genes.Notably,GXKP01 did not carry any virulence factors and antibiotic-resistance genes,confirming its genetic safety. 【Conclusion】 This study isolated a lytic phage capable of targeting K57-type carbapenem-resistant Klebsiella pneumoniae,laying a foundation for future phage-based prevention and treatment of infections caused by hypervirulent,drug-resistant Klebsiella pneumoniae.

Key words: phage; isolation and identification; carbapenem-resistant Klebsiella pneumoniae; whole genome sequencing

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