Examining the Frequency of Carbapenem Resistance Genes and Its Relationship with Different Classes of Integrons Including Classes I and II in Pseudomonas aeruginosa Isolates of Burn Patients

Abstract

Background: Pseudomonas aeruginosa is one of the most important opportunistic pathogens causing hospital infections. Objectives: This study aimed to investigate the abundance of integrons and the pattern of resistance to carbapenems (metallo-β-lactamases including Spm, Imp, and Vim) and its relationship with the presence of integrons classes I and II in P. aeruginosa isolates. Methods: This study was conducted on 73 samples of P. aeruginosa isolated from burn wounds of patients admitted to the burn center of Velayat Hospital, Rasht, Iran. To confirm the phenotype of P. aeruginosa, Gram staining and diagnostic biochemical tests, including oxidation-fermentation (OF), pigment production, citrate utilization, catalase activity, oxidase test, and growth at 42°C, were used. After identification and confirmation, molecular diagnosis was conducted to identify strains producing genes classes I and II using the polymerase chain reaction (PCR) method. Results: In this research, the frequency of carbapenem resistance genes in clinical isolates of P. aeruginosa was found to be zero, 13.7%, and 21.9% for blaSpm, blaImp, and blaVim genes, respectively. Integrons of classes I and II were present in 53.4% of isolates of class I and 17.8% of isolates of class II. Also, 4.1% of the total integrin-positive isolates had both integron classes. Conclusions: There was a statistically significant relationship between class I integron and the blaImp gene. Importantly, the mechanisms of other integrons play a role in the development of resistance and the presence of these genes involved in this project.