Spread of Efflux Pump Overexpressing-Mediated Fluoroquinolone Resistance and Multidrug Resistance inPseudomonas aeruginosaby using an Efflux Pump Inhibitor

Abstract

BackgroundFluoroquinolone resistance in Pseudomonas aeruginosa may be due to efflux pump overexpression and/or target mutations. We designed this study to investigate the efflux pump mediated fluoroquinolone resistance and check the increasing effectiveness of fluoroquinolones in combination with an efflux pumps inhibitor among P. aeruginosa isolates from burn wounds infections.Materials and MethodsA total of 154 consecutive strains of P. aeruginosa were recovered from separate patients hospitalized in a burn hospital, Tehran, Iran. The isolates first were studied by disk diffusion antibiogram for 11 antibiotics and then minimum inhibitory concentration (MIC) experiments were performed to detect synergy between ciprofloxacin and the efflux pump inhibitor, carbonyl cyanide-m-chlorophenyl hydrazone (CCCP). Then to elucidate the inducing of multi drug resistance due to different efflux pumps activation in Fluoroquinolone resistant isolates, synergy experiments were also performed in random ciprofloxacin resistant isolates which have overexpressed efflux pumps phenotypically, using CCCP and selected antibiotics as markers for Beta-lactams and Aminoglycosides. The isolates were also tested by polymerase chain reaction (PCR) for the presence of the MexA, MexC and MexE, which encode the efflux pumps MexAB-OprM, MexCD-OprJ and MexEF-OprN.ResultsMost of the isolates were resistant to 3 or more antibiotics tested. More than half of the ciprofloxacin resistant isolates exhibited synergy between ciprofloxacin and CCCP, indicating the efflux pump activity contributed to the ciprofloxacin resistance. Also increased susceptibility of random ciprofloxacin resistant isolates of P. aeruginosa to other selected antibiotics, in presence of CCCP, implied multidrug extrusion by different active efflux pump in fluoroquinolones resistant strains. All of Ciprofloxacin resistant isolates were positive for MexA, MexC and MexE genes simultaneously.ConclusionIn this burn hospital, where multidrug resistant P. aeruginosa isolates were prevalent, ciprofloxacin resistance and multidrug resistance due to the overexpression of fluoroquinolones mediated efflux pumps has also now emerged. Early recognition of this resistance mechanism should allow the use of alternative antibiotics and use an efflux pumps inhibitor in combination with antibiotic therapy.

Role of efflux pump inhibitor in decreasing antibiotic cross-resistance of Pseudomonas aeruginosa in a burn hospital in Iran

“…Infections caused by P. aeruginosa are related to significant morbidity and mortality [1,2]. The organism exhibits a high level of intrinsic resistance and only a limited number of antimicrobial agents are active against it [3]. In addition, P. aeruginosa has a remarkable ability to acquire further resistance mechanisms to multiple groups of antimicrobial agents, including beta-lactams, aminoglycosides, and fluoroquinolones [4].…”

“…To recognize the presence of acquired multidrug resistance due to efflux pump overexpression, phenotypic and genotypic tests may be used in laboratory practice [3]. Increased expression of efflux pumps could increase the minimum inhibitory concentrations (MICs) of antimicrobials agents [3].…”

“…To recognize the presence of acquired multidrug resistance due to efflux pump overexpression, phenotypic and genotypic tests may be used in laboratory practice [3]. Increased expression of efflux pumps could increase the minimum inhibitory concentrations (MICs) of antimicrobials agents [3]. A series of different compounds have been identified as efflux pump inhibitors with the ability to broadly inhibit several identified multidrug efflux pumps in P. aeruginosa [6].…”

Biofilm: An Important Bacterial Feature Still to Deal With

“…Gramnegative bacteria may regulate the permeability of the outer membrane by expression of porins, which are membrane protein channels for passive diffusion. P. aeruginosa is a bacterium that has at least four efflux pumps [34].…”

Genome-wide antibiotic resistance and virulence profiling of Pseudomonas Aeruginosa isolated from clinical samples in Lebanon

“…PCR assays were performed using the following primers: oprI F (5'-ATGAACAACGTTCTGAAATTCTCTGCT-3') and oprI R (5'-CTTGCGGCTGGCTTTTTCCAG-3') amplifying a 249 bp fragment of the oprI gene, oprL F (5'-ATGGAAATGCTGAAATTCGGC-3') and oprL R (5'-CTTCTTCAGCTCGACGCGACG) amplifying a 504 bp fragment of the oprL gene, oprD F (5'-CGCCGACAAGAAGAACTAGC-3') and oprD R (5'-GTCGATTACAGGATCGACAG-3') amplifying a 1412 bp of the oprD gene (Adabi et al, 2015;Poonsuk et al, 2014). PCR mixture contained 2 µl of template DNA, 20…”