Prevalence of Hypervirulent rmpA and magA Genes in Clinical Isolates of Klebsiella pneumoniae and their association with Drug Resistant Pattern: A Cross-sectional Study

Abstract

Introduction: Hypervirulent Klebsiella pneumoniae (hvKp) has emerged as a pathogen of global concern that is hypermucoviscous, causing infections and rapidly acquiring Antimicrobial Resistance (AMR). HvKp is more virulent than classical K. pneumoniae (cKp) and frequently infects healthy individuals with community-acquired illnesses. Since hvKp commonly exists in the gastrointestinal tract, its communicable spread affects the general public and healthcare facilities. The study was necessary due to the rapid evolution of hvKp, the need to identify novel, reliable agents of hypervirulence and drug resistance, and more reliable targets for therapeutic intervention. Aim: To investigate the prevalence of hvKp strains (rmpA and magA genes) and drug-resistant patterns in clinical isolates of Klebsiella pneumoniae (K. pneumoniae) in a tertiary care hospital in Puducherry, India. Materials and Methods: The cross-sectional study included a total of 100 non duplicate consecutive isolates of K. pneumoniae collected from Mahatma Gandhi Medical College and Research Institute and Hospital, Puducherry, India. These isolates were recovered from various clinical specimens such as urine, sputum, pus, blood, and other miscellaneous specimens mainly obtained from both outpatients and inpatients between August 2021 and April 2022. The antibiotic susceptibility of cultured K. pneumoniae was determined by the disk-diffusion test following the 2020 Clinical and Laboratory Standards Institute (CLSI) guidelines. The rmpA and magA genes were detected using conventional Polymerase Chain Reaction (PCR). PCR products were sequenced using Sanger sequencing. Statistical analysis was performed using Statistical Package for the Social Sciences (SPSS) statistics software for Windows, version 15.0 (available from SPSS Inc., Chicago, USA). A p-value <0.05 was considered statistically significant. Results: A total of 100 isolates were studied for phenotypic and genotypic properties. HvKp was identified phenotypically using the string test, and further, the rmpA and magA genes were identified genotypically using PCR. Out of 100 isolates, the phenotypic study showed 11 (11%) isolates as string test positive. Furthermore, genotypic results showed that 22 (22%) isolates expressed the rmpA gene, 11 (11%) isolates expressed the magA gene, and 7 (7%) isolates expressed both rmpA and magA. Most of the hvKp isolates were obtained from urine specimens of K. pneumoniae isolates and showed more resistance than cKp towards all classes of antibiotics. Conclusion: The high prevalence of rmpA and magA genes suggests their strong role and capability as genetic markers for the identification of hvKp in the laboratory. This study indicated the important role of genetic elements in the emergence of drug resistance in hypervirulent strains and showed that hvKp has a multidrug resistance pattern.

Keywords

• antibiotic drug resistance pattern
• classical klebsiella pneumoniae
• mucoviscosity associated genotype aerobactin gene
• regulator mucoid phenotype aerobactin gene