The frequency of class 1 integrons in multi-drug resistant Klebsiella pneumoniae isolated from clinical samples using polymerase chain reaction assay

The development of multidrug resistant (MDR) strains of K. pneumoniae is a matter of great concern and horizontal transfer of integrons is one of the most important factors in the creation of multidrug-resistant (MDR) bacteria. This study was aimed to determine the frequency of class 1 integrons and their gene cassettes among MDR K. pneumonia strains isolated from clinical specimens.
This cross-sectional study included 181 samples of Klebsiella pneumoniae isolated from outpatients and hospitalized patients between November 2013 and June 2014. Antimicrobial susceptibility patterns of isolated samples were determined by disk diffusion method according to the CLSI guidelines. The presence of class 1 integrons and embedded gene cassettes were investigated in MDR strains by polymerase chain reaction assay. Using SPSS 17, statistical analyses were carried out by chi-square (χ2) and Fisher exact tests. P-values of less than 0.05 were considered statistically significant.
Of 181 isolated samples, 150 (82.9%) were multidrug resistant. The most and the least resistance rates belonged to ampicillin (98.7%) and imipenem (24%) respectively. Class I integrons were seen in 150 (100%) of MDR isolated samples and 147 (98%) of them contained gene cassettes of five different kinds.
We found a high frequency rate of class 1 integrons and embedded gene cassettes in MDR Klebsiella pneumoniae in the hospitalized patients in Kashan which can play an important role in the creation and transmission of antibiotic resistance.