Pan-genome analysis of Hypervirulent Klebsiella pneumoniae to evaluate genomic diversity and pathogenic potential among strains

Abstract Klebsiella pneumoniae is the causative agent of numerous types of infections in humans, includes urinary tract infections (UTIs), respiratory tract infections, and bloodstream infections. The hypervirulent Klebsiella pneumoniae associated with severe community-acquired infections. Hypervirulent Klebsiella pneumoniae(hvKP) is more virulent than classical Klebsiella pneumoniae (cKP) and it is an evolving pathotype due to the acquisition of genetic determinants which is responsible for its open genome. In the present study, we have performed the pan-genome analysis of Klebsiella pneumoniae for the determination of virulence proteins and genomic variation among its strains using a tool pangenome analysis pipeline (PGAP-1.2.1). The whole genome sequences of fifty-one Klebsiella pneumoniae strains was downloaded from NCBI using Refseq database. These sequences were converted into PGAP required extension files. Thirty-nine proteins and their corresponding protein sequences involved in the pathogenesis of the organism were downloaded from UniprotKB for BLAST analysis. After blast analysis, twenty-five strains were selected out of fifty-one strains based on 90-100% homology. A wide variety of selected pathogenic proteins were present in core and shared genome which includes siderophores specifically (salmochelin), adhesion proteins, extracellular toxins, and complement resistant proteins. The presence of carbapenem resistance and hypermucoviscosity proteins in unique genome indicated that Klebsiella pneumoniaeis continuously evolving through horizontal gene transfer (HGT). Additionally, the presence of siderophores like salmochelin and aerobactin indicates the presence of hypervirulent Klebsiella pneumoniae. Phylogenetic tree shows that strain GCF_000009885 (NTUH-K2044) was distant from all the other strains.