一株高毒力肺炎克雷伯菌噬菌体的基因组和生物学特征分析  

The genomic and biological characteristics of a hypervirulent klebsiella pneumoniae bacteriophage

作　　者：甘霖 田紫妍 袁静[1] Gan Lin;Tian Ziyan;Yuan Jing(Department of Bacteriology,Capital Institute of Pediatrics,Beijing 100020,China)

机构地区：[1]首都儿科研究所细菌学研究室,北京100020

出　　处：《遵义医科大学学报》2025年第4期325-331,共7页Journal of Zunyi Medical University

基　　金：国家自然科学基金资助项目(NO:82402639);北京市属医院科研培育计划项目(NO:PX2025048)。

摘　　要：目的分离鉴定一株具有临床应用价值潜力的高毒力Kp噬菌体,为开发新型抗菌制剂提供依据。方法使用高毒力Kp(hvKp)菌株QD22作为宿主菌,分离鉴定一株可裂解该菌株的噬菌体,并对噬菌体的基因组特征、形态学特征、环境压力耐受性、宿主菌裂解能力和宿主谱范围进行分析。结果以hvKp菌株QD22作为宿主菌分离噬菌体,得到的噬菌体PTF1不仅可裂解QD22,还可裂解多株hvKp菌株,对hvKp菌株的裂解率高达31.9%。从序列型和荚膜型分析发现,PTF1对序列23型和荚膜K1型的裂解率分别为87.5%和86.7%。噬菌体PTF1属于短尾噬菌体科Podoviridae,无毒力基因和耐药基因。生物学特征分析显示,PTF1最佳感染复数(MOI)仅为10^(-3),最大爆发量为120 PFU/cell,MOI低至10-6时也可完全抑制宿主菌的增殖。环境压力耐受性分析也提示,PTF1在温度4~60℃和pH 4~10时均可保持较高的生物学活性。结论噬菌体PTF1是一株具有一定裂解性和环境压力耐受性的短尾噬菌体,可裂解31.9%的高毒力hvKp菌株,具有较强的临床应用潜力。Objective To isolate and identify a hypervirulent Kp(hvKp)bacteriophage with potential clinical application value,providing a basis for the development of novel antimicrobial agents.Methods Using a hvKp isolate as the host bacterium,we isolated and characterized a bacteriophage capable of lysing this strain.The genomic features,morphological characteristics,environmental stress tolerance,lysis efficiency,and host range were analyzed for the identified bacteriophage.Results Employing the hvKp isolate QD22 as the host bacterium for phage isolation,the obtained phage PTF1 was found not only to lyse QD22 but also multiple other hvKp isolates,with a lysis rate of up to 31.9%against hvKp isolates.Sequence type and capsular type analysis revealed that the lysis rates of PTF1 against isolates of sequence type 23 and capsule type K1 were 87.5%and 86.7%,respectively.Phage PTF1 belongs to the Podoviridae family and lacks virulence genes and antibiotic resistance genes.Biological characteristic analysis revealed that the optimal multiplicity of infection(MOI)for PTF1 is as low as 10^(-3),with a maximum burst size of 120 PFU per cell.Even at an MOI as low as 10-6,PTF1 can completely inhibit the proliferation of the host bacterium.Environmental stress tolerance analysis indicated that PTF1 maintains high biological activity across a temperature range of 4~60℃and pH levels from 4 to 10.Conclusion Phage PTF1 is a short-tailed phage with lytic efficiency and environmental stress tolerance,capable of lysing 31.9%of hvKp isolates,indicating significant potential for clinical applications.

关 键 词：肺炎克雷伯菌 噬菌体 高毒力 荚膜型 

分 类 号：Q939.48[生物学—微生物学]