The Role of Efflux Pump Genes (qacE, qacE-Δ1,and sug E1) in Carbapenems and Biocides Resistance among Pseudomonas aeruginosa Isolated from Burn Infections

Abstract

Burn injuries cause the skin's defenses against opportunistic infections to be compromised. One of the primary pathogens that colonize burn wounds and cause serious infections is pseudomonas aeruginosa. Appropriate treatment options and time are limited by antibiotic resistance, biofilm production, and other virulence factors. The study samples, which comprised 150 clinical specimens in the form of burn swabs from patients with burn infections, admitted to four hospitals in Baghdad, Iraq, were collected between November 2022 and the end of February 2023.  Of all the bacterial cultures that were collected, 45 isolates (30%) were identified as P. aeruginosa based on the results of selective media, biochemical tests, and the VITEK2 system. The results of the disc diffusion method's antimicrobial susceptibility test for the isolates under investigation showed that P. aeruginosa clinical isolates had moderate resistance to most of the tested antibiotics. Most P. aeruginosa isolates exhibited high resistance to Tetracycline, Piperacillin, and Piperacillin-tazobactam, as well as to Ceftazidime (84.44%) and Cefepime (75.55%). Also, the highest sensitivity was recorded for Colistin, Tigecycline. All P. aeruginosa isolates that showed resistance to imipenem and meropenem antibiotics (n = 14) as well as ten isolates that were sensitive to these antibiotics were used for molecular study. Polymerase chain reaction (PCR) has been used for evaluate the presence of the identification gene (16S rRNA) and efflux pump genes (qacE, qacE-Δ1, and sug E1). The results of the efflux pump gene detection showed that all carbapenem-resistant isolates with high resistance to antibacterial agents (chlorohexidine, dettol, and EDTA) had the efflux pump genes, with the exception of the isolates P11, P13, and P14, where the isolates P11 and P14 did not have the gene sug E1, and isolate P12 showed the absence of the gene qacE. The findings showed that all of the resistant isolates had the gene qacE-Δ1. Also, it was found that the majority of the isolates which sensitive to carbapenems did not have the efflux pump genes. In conclusion, there is a significant correlation between the presence of efflux pump gene and the resistance of carbapenems and biocides (chlorohexidine, Dettol, and EDTA), where the high MICs values were related with isolates that have the efflux pump genes.