Emergence of Multidrug Resistant Hypervirulent ST23 Klebsiella pneumoniae: Multidrug Resistant Plasmid Acquisition Drives Evolution

Frontiers in Cellular and Infection Microbiology

Rohit Biswas¹  Jobin John Jacob²  Dhiviya Prabaa Muthuirulandi Sethuvel²  Chaitra Shankar²  Karthick Vasudevan²  Balaji Veeraraghavan²  Abi Manesh³  Indranil Biswas⁴  Santosh Varughese⁵ 

[1] College of Biological Sciences, University of Minnesota, Saint Paul, MN, United States;Department of Clinical Microbiology, Christian Medical College and Hospital, Vellore, India;Department of Infectious Diseases, Christian Medical College and Hospital, Vellore, India;Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Centre, Kansas City, KS, United States;Department of Nephrology, Christian Medical College and Hospital, Vellore, India;

关键词: Klebsiella pneumoniae;    hypervirulence plasmid;    ST23;    hybrid genome;    multidrug resistance;    OXA-232;   

DOI  :  10.3389/fcimb.2020.575289

来源: DOAJ

【 摘 要 】

BackgroundIn recent years, the emergence of multidrug resistant hypervirulent K. pneumoniae (MDR hvKp) isolates poses severe therapeutic challenge to global public health. The present study used the complete genome sequence of two MDR hvKp isolates belonging to ST23 to characterize the phylogenetic background and plasmid diversity.MethodsTwo hvKp isolates from patients with bacteremia were sequenced using Ion Torrent PGM and Oxford Nanopore MinION platforms and assembled by hybrid genome assembly approach. Comparative genomics approaches were used to investigate the population structure, evolution, virulence, and antimicrobial resistance of MDR hvKp strains.ResultsThe study isolates exhibited typical features of hvKp phenotypes associated with ST23. The convergence of multidrug resistance and hypervirulence were attributed by the presence of multiple plasmids including a 216 kb virulence plasmid and MDR plasmids belonging to IncA/C2, IncFIB, IncX3, and ColKP3 groups. The insertion of catA1 gene into virulence plasmid was observed along with genetic factors such as aerobactin, salmochelin, and rmpA2 that confer hvKp’s hypervirulent phenotype. The core genome single nucleotide polymorphism (SNP) phylogenetic analyses of the isolates showed the evolution of ST23 hvKp was predominantly driven by ICEKp acquisitions.ConclusionTo the best of our knowledge, this is the first report of MDR hvKp isolates of ST23 with insertion of catA1 gene into the virulence plasmid which presents the possibility of hotspot integration sites on the plasmids to aid acquisition of AMR genes. ST23 is no longer confined to susceptible strains of hvKp. Our findings emphasize the need for more studies on recombinant events, plasmid transmission dynamics and evolutionary process involving hvKp.

【 授权许可】

Unknown