Molecular Characterization of Klebsiella Pneumoniae with Special Reference to Its Virulence and Antibiotic Resistance

Abstract

Klebsiella pneumoniae, a gram negative bacteria belonging to the family of enterobacteriaceae is known to cause a wide range of infections in the nosocomial settings. The recent research around the globe has proved that multidrug resistance is a challenging threat encountered while treating infections caused by this bacteria. The present study was conducted to analyze the multidrug resistance pattern of the bacteria in the laboratory setting. A total of 261 clinical isolates were collected from a tertiary care hospital from both male and female patients. Antibiotic susceptibility testing for all the samples were performed by vitek 2 systems as per the CLSI guidelines. From the results obtained from the AST, the clinical isolates were subjected to various phenotypic and genotypic assays to identify the presence of AmpC, ESBL s and Carbapenamse producers. An MPC assay was conducted to determine the resistance of the organism against ciprofloaxacin. Genotypic research was also conducted on randomly selected isolates to determine the presence of virulence genes. A whole genome analysis was performed for one K. pneumoniae isolate (219) and the results were analysed by RAST and Prokka. The present study shows that the isolates selected for this study revealed a high resistance pattern to cephalosporins and fluroquinolones, though a majority of them were still susceptible to piperacillin, tazobactum, carbapenems and tigecycline. Around 20% and 40% were AmpC and ESBL producers though none were resistant to colistin. MPC assay helps in determining the therapeutic options and the two genes; qnrS and qnrB were harboured by 11 isolates among the fifteen tested. uge and mrkD were the most predominant virulence genes detected in this study. The whole genome sequencing of the isolate number 219 revealed that the genome size was 5,038,803 base pairs and the total protein count is 5330 with a GC content of 57.2%. Though most of the genes detected the presence of various mechanisms of resistance, aminoglycoside resistance, quinolo