# Antimicrobial resistance and real-time PCR detection of blaKPC in Klebsiella pneumoniae isolated from wound infections in a tertiary care hospital

## TL;DR

This study found that nearly 20% of Klebsiella pneumoniae wound infection isolates in a North Indian hospital were resistant to carbapenems due to the blaKPC gene.

## Contribution

The study introduces a real-time PCR method for detecting the blaKPC gene in clinical isolates with high diagnostic accuracy.

## Key findings

- 19.6% of K. pneumoniae isolates were resistant to meropenem and carried the blaKPC gene.
- qPCR for blaKPC detection showed an area under the curve of 0.99, indicating high accuracy.
- Multidrug resistance was common, with over 90% resistance to amikacin, ceftazidime, ampicillin, and cefazolin among resistant isolates.

## Abstract

Klebsiella pneumoniae is a common Gram-negative bacterium frequently associated with wound infections. A major public health concern is the emergence of carbapenem-resistant strains, particularly those carrying the blaKPC gene. This study aimed to detect the blaKPC gene and to determine the antibiotic resistance patterns of K. pneumoniae isolates obtained from wound specimens in a tertiary care hospital in North India.

A total of 1,080 wound swab specimens were collected between October 2023 and September 2024. The isolates were identified as K. pneumoniae using the VITEK-2 identification system and standard biochemical tests. Antimicrobial susceptibility was determined with the Kirby–Bauer disk diffusion method and broth microdilution, interpreted according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. Carbapenemase production was assessed using the modified Hodge test. Real-time quantitative PCR (qPCR), with 16S rRNA as the internal control, was employed to detect the blaKPC gene in isolates resistant to meropenem.

Out of 560 K. pneumoniae isolates, 110 (19.6%) were resistant to meropenem. These resistant isolates also displayed high rates of multidrug resistance, with over 90% resistant to amikacin, ceftazidime, ampicillin, and cefazolin. The qPCR assay revealed that all 110 meropenem-resistant isolates carried the blaKPC gene, with PCR cycle threshold (Ct) values ranging from 12 to 32. No amplification was observed in the meropenem-sensitive negative controls. The diagnostic performance of the qPCR assay demonstrated an area under the curve (AUC) of 0.99, confirming its high accuracy as a diagnostic tool. Furthermore, 83.6% of the isolates harboring the blaKPC gene.

In conclusion, K. pneumoniae isolates exhibit a concerning rate of carbapenem resistance mediated by the blaKPC gene. Antimicrobial stewardship and molecular surveillance are crucial for the prevention of the spread of carbapenem-resistant K. pneumoniae in clinical settings.