Induction and Circular Structure Analysis of Prophage in Carbapenem-resistant Hypermucoviscous Klebsiella pneumoniae K2-ST375
[Objective]To analyze and study the distribution of prophages,genetic structure of inducible prophages,and the characteristics of their encoded genes in clinical carbapenem-resistant hypermucoviscous Klebsiella pneumoniae(CR-HMKP)K2-ST375 strain,this may lay an important foundation for further research on the biological functions of prophage in CR-HMKP.[Method]The distribution of prophages in CR-HMKP K2-ST375 strain was predicted using Prophage Hunter.Mitomycin C was used to induce the prophages and their circular structure was verified through circularization primers.Comprehensive bioinformatics software such as RAST were utilized to annotate the genes of the inducible prophage,Prophage-4,and to analyze the physicochemical properties,structural characteristics,and genetic information of the endolysin encoded by Prophage-4.[Results]The predicted results of Prophage Hunter indicate that the chromosome of CR-HMKP K2-ST375 strain carries a total of four active prophages,named Prophage-1-Prophage-4.Upon induction with mitomycin C,Prophage-4 can be excised from the host chromosome to form a circular structure.Sequence analysis shows that there is a 40 bp homologous repeats sequence between Prophage-4 and the host chromosome.Gene annotation results suggest that the genes encoded by Prophage-4 are mainly involved in phage structure and assembly,DNA metabolism,lysogenic cycle,and host lysis.The endolysin encoded by Prophage-4 shares the same conserved structural domains with the endolysin R21-like protein of the Enterobacteriaceae bacteriophage P21.Genetically,they are closely related in terms of evolutionary lineage.Phylogenetic tree analysis results show that Prophage-4 and the lytic Klebsiella phage BUCT541 are located on the same evolutionary branch,indicating that Prophage-4 possesses potential lytic capabilities.[Conclusion]The Prophage-4 carried in clinical CR-HMKP K2-ST375 strain can be induced by mitomycin C and excised from the host's chromosome to form a circular structure mediated by 40 bp homologous repeat sequences.The endolysin is closely related to the endolysin protein encoded by phage P21.
万方数据
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