Detection of HypervirulentKlebsiella pneumoniaefrom Clinical Samples in Tamil Nadu

Abstract

AbstractKlebsiellapneumoniae is one of the significant opportunistic pathogens which cause both nosocomial and community-acquired infections. This study focuses on the molecular characterization of hypervirulentK. pneumoniaeisolated from clinical samples in Tamil Nadu. A total of 30 clinicalK. pneumoniaeisolates were collected from the diagnostic centres located in Trichy, Madurai, and Chennai. On subjected to the antibiotic susceptibility testing, it was found that 73% were multi-drug resistant. The string test showed that 46.6% of the isolates were hypermucoviscous (HMV). Molecular studies revealed the absence ofmcr (1-5)genes. The isolates belonging to capsular types K1 (n=5), K2 (n=6) and K5 (n=2) were detected. Virulence genes namelyrmpA(n=5), aerobactin (n=8), andKfuBC(n=8) were identified using multiplex polymerase chain reaction. Through molecular studies, 22 isolates were found to be classicalK. pneumoniae(cKP) and 8 were hypervirulentK. pneumoniae(hvKP). The genome sequencing of five isolates revealed that the strains belong to ST86 and ST23.In vivostudies usingGalleria mellonellashowed that HMV-hvKP strains were highly pathogenic among the hvKP strains and the non-K1/K2 and K2 strains were pathogenic among the cKP strains. Our data revealed the emergence of colistin-resistant hvKP strains in Tamil Nadu, India.