Diversity and Distribution of β-Lactamase Genes Circulating in Indian Isolates of Multidrug-Resistant Klebsiella pneumoniae

Klebsiella pneumoniae (Kp) has gained prominence in the last two decades due to its global spread as a multidrug-resistant (MDR) pathogen. Further, carbapenem-resistant Kp are emerging at an alarming rate. The objective of this study was (1) to evaluate the prevalence of beta-lactamases, especially carbapenemases, in Kp isolates from India, and (2) determine the most prevalent sequence type (ST) and plasmids, and their association with beta-lactamases. Clinical samples of K. pneumoniae (n = 65) were collected from various pathology labs, and drug susceptibility and minimum inhibitory concentrations (MIC) were detected. Whole genome sequencing (WGS) was performed for n = 22 resistant isolates, including multidrug-resistant (MDR) (n = 4), extensively drug-resistant (XDR) (n = 15), and pandrug-resistant (PDR) (n = 3) categories, and genomic analysis was performed using various bioinformatics tools. Additional Indian MDRKp genomes (n = 187) were retrieved using the Pathosystems Resource Integration Center (PATRIC) database. Detection of beta-lactamase genes, location (on chromosome or plasmid), plasmid replicons, and ST of genomes was carried out using CARD, mlplasmids, PlasmidFinder, and PubMLST, respectively. All data were analyzed and summarized using the iTOL tool. ST231 was highest, followed by ST147, ST2096, and ST14, among Indian isolates. bla(ampH) was detected as the most prevalent gene, followed by bla(CTX-M-15) and bla(TEM-1). Among carbapenemase genes, bla(OXA-232) was prevalent and associated with ST231, ST2096, and ST14, which was followed by bla(NDM-5), which was observed to be prevalent in ST147, ST395, and ST437. ST231 genomes were most commonly found to carry Col440I and ColKP3 plasmids. ST16 carried mainly ColKP3, and Col(BS512) was abundantly present in ST147 genomes. One Kp isolate with a novel MLST profile was identified, which carried bla(CTX-M-15), bla(OXA-1), and bla(TEM-1). ST16 and ST14 are mostly dual-producers of carbapenem and ESBL genes and could be emerging high-risk clones in India.

Automated summary

The prevalence of beta-lactamases, especially carbapenemases, in Klebsiella pneumoniae isolates from India was evaluated in this study. The most prevalent sequence types (ST) among Indian isolates were ST231, ST147, ST2096, and ST14. The gene bla(ampH) was found to be the most prevalent, followed by bla(CTX-M-15) and bla(TEM-1). The study also identified ST16 and ST14 as potential high-risk clones in India, capable of producing both carbapenemases and ESBL genes.