DOI: 10.4103/mgmj.mgmj_98_26 ISSN: 2347-7946
Phenotypic and genotypic characterization of extended-spectrum β-lactamase-producing hypervirulent Klebsiella pneumoniae isolates from a tertiary care hospital in Haryana, India
Shristi Tiwari, Mukesh Sharma, Moumita Sardar, Leimapokpam Sumitra Devi Abstract
Background:
The increasing prevalence of multidrug-resistant (MDR) hypervirulent
Klebsiella pneumoniae
poses a major therapeutic challenge because the convergence of enhanced virulence and extensive antimicrobial resistance results in severe, difficult-to-treat infections.
Objective:
This study aimed to identify hypervirulent strains among extended-spectrum β-lactamase (ESBL)-producing
K. pneumoniae
isolates from diverse clinical specimens using both phenotypic and genotypic methods.
Materials and Methods:
This cross-sectional study was conducted over 12 months (April 2025 to March 2026) at a tertiary care hospital in Haryana, India. A total of 142
K. pneumoniae
isolates were recovered from clinical specimens. Antimicrobial susceptibility testing was performed using the Kirby–Bauer disk diffusion method, and ESBL production was detected using HiCrome ESBL agar. Hypervirulent isolates were identified phenotypically by the string test and genotypically by conventional uniplex polymerase chain reaction to detect the virulence-associated genes
iucA
and
rmpA
.
Results:
A total of 142
K. pneumoniae
isolates were recovered during the study period. ESBL production was detected in 116 (81.7%) isolates, with respiratory specimens (
n
= 39) the most common source. Among all isolates, 94 (66.2%) were positive on the string test, and 73 (51.4%) carried one or both virulence-associated genes (
iucA
and/or
rmpA
). Multidrug resistance was observed in 121 (85.2%) isolates, and all potential ESBL-producing isolates exhibited an MDR phenotype.
Conclusion:
The study highlights the growing burden of hypervirulent ESBL-producing
K. pneumoniae
and underscores the need for prompt detection and accurate identification to enable timely, appropriate antimicrobial therapy. Although phenotypic methods are valuable screening tools, molecular techniques remain essential for definitive identification of hypervirulent strains.