Efflux MexAB-Mediated Resistance in Multidrug and Pan-Drug Resistant Strains of Pseudomonas aeruginosa Isolated From Patients With Burn and Wound Infections

Abstract

Background: The emergence of highly drug resistant Pseudomonas aeruginosa in burn wounds is becoming a challenging problem for infection control programs. Today, it has been shown that antibiotic resistance in P. aeruginosa is the result of synergism between membrane permeability and multidrug resistance (MDR) efflux pumps. Objectives: The aim of this study was to investigate MDR and pan-drug resistance (PDR) in P. aeruginosa and detection of the presence of efflux pump MexAB genes by the polymerase chain reaction (PCR) technique. Materials and Methods: One-hundred and fifty P. aeruginosa were isolated from burn and wound infections. The isolates were confirmed using conventional culture and biochemical tests. Antibiotic resistance was evaluated using agar disk diffusion and broth micro dilution tests. For detection of efflux pump MexAB genes, the PCR technique with subsequent sequencing was used. Results: In total, 99 strains (66%) were MDR and one strain (0.667%) was PDR as detected by traditional susceptibility tests. The MDR isolates belonged to 53 burn (70.66%) and 46 wound (61.33%) infections. The PDR was only seen in one isolate from a burn strain (1.33%). The PCR technique revealed that all the 99 MDR strains and one PDR strain, contained MexA and MexB genes, representing an exhibitive intrinsic existence of these genes in MDR and PDR of P. aeruginosa. Conclusions: This study represented an increasing rate of MDR P. aeruginosa in burn and wound samples. Efflux MexAB genes were detected in all MDR and PDR strains. The P. aeruginosa strain isolated from burn cases showed higher drug resistance and PDR resistance was only noted in a burn sample.

Efflux MexAB-Mediated Resistance in P. aeruginosa Isolated from Patients with Healthcare Associated Infections

“…Our data showed high prevalence of MDR among the isolated strains (70%), and only (5.5%) of the isolates were PDR. In concordance with our results, a study from Iran published in 2016, reported high MDR rate in P. aeruginosa isolates (66%) from burns unit and only one strain was PDR (0.66%) [30].…”

Frequency of Chromosomally Encoded gyrA and parC Genetic Determinants of Fluoroquinolone Resistance in A. baumannii

“…This result correlates with the earlier study conducted in Iran documenting 90% positivity for the gyrA mediated ciprofloxacin resistant strains of A. baumannii [13]. In addition, gyrA mediated ciprofloxacin resistance is high when compared to the efflux pump mediated resistance which is considered as a secondary mechanism in inducing ciprofloxacin resistance among A. baumannii [14]. This documents the high-level resistance against fluoroquinolones mediated by gyrA and parC which is normally associated with a double mutation rather than multiple mutations recorded in other gram negative bacilli such as E.coli [15,16].…”

Efflux pump inhibition versus quorum sensing inhibition in hospital acquired multidrug resistant Pseudomonas aeruginosa isolates in Mansoura University Hospitals

“…In this study, the most effective drugs against P. aeruginosa infections were colistin (100%) and polymyxin B (98%), while the least effective drugs were cefepime (20%) and ceftazidime (16%). Our results are near to results of Khoravi & Mohammadian 21 , who reported that the most effective antibiotic against P. aeruginosa was polymyxin B (96%), and the least effective one was cefepime (20%). Also, a study in Egypt 22 reported that the most effective antibiotic against P. aeruginosa was colistin (84%), whereas the least effective ones belonged to 3 rd generation cephalosporins.…”