[Determination of Class-1 and Class-2 Integron Gen Casettes in Klebsiella pneumoniae Causing Ventilator-associated Pneumonia].

Abstract

Klebsiella pneumoniae is a major pathogen in ventilator-associated pneumonia (VAP) and poses a significant challenge in healthcare-associated infections due to its multidrug resistance (MDR). Mobile genetic elements such as integrons are key factors in the spread of resistance genes in pathogens like K.pneumoniae. This study aimed to detect class 1 and class 2 integron gene cassettes in K.pneumoniae isolates from VAP patients. A total of 22 isolates were collected between 2022 and 2023 from the intensive care unit of Kırşehir Training and Research Hospital. DNA was extracted using the boiling method and integrons were amplified via polymerase chain reaction with specific primers. Amplified fragments were cloned into the pJET1.2/blunt vector and sequenced. Sequences were processed using BioEdit and compared with the NCBI BLAST GenBank database to identify gene cassette contents. Identified sequences were submitted to GenBank and assigned accession numbers. Class 1 integrons were found in five isolates (22.7%) and class 2 integrons in two isolates (9.1%). Class 1 integrons harboured dfrA12 responsible for trimethoprim resistance and aadA which provides resistance to aminoglycoside group antibiotics. In class 2 integrons, dfrA1, sat2 and aadA1 were identified which confer resistance to trimethoprim, streptothricin and streptomycin/spectinomycin, respectively. The results of this study demonstrate that integrons play a significant role in the spread of hospital-acquired MDR K.pneumoniae isolates. Strengthening infection control measures and monitoring antibiotic resistance mechanisms are crucial for controlling antibiotic-resistant isolates seen in hospitals. This study will contribute to understanding the genetic makeup of VAP-related K.pneumoniae isolates, determining appropriate treatment approaches and controlling hospital-acquired infections.