Frequency of MexA gene in pseudomonas aeruginosa isolated from clinical samples of a Tertiary Care Hospital in Pakistan.

Abstract

The drug resistance genes are responsible to preserve the Pseudomonas. This also happens in the case of Mex drug efflux pumps and expression increase of MexA, MexB and OprM genes in Pseudomonas aeruginosa, when grown in sub-inhibitory concentrations of antibiotics. Objectives: This study was designed to detect the MexA gene of Pseudomonas aeruginosa resistant strains in tertiary care hospital, Peshawar. Study Design: Cross-sectional study. Setting: Department of Pathology, Khyber Teaching Hospital, Peshawar, Pakistan. Period: 14 months duration from April 2015 to May 2016. Material & Methods: The specimens including burn wound swabs, pus and urine were obtained from different patients and were processed on blood agar and MacConkey medium for isolation and identification. Conventional PCR was performed for the MexA gene on 50 specimens. Results: The simple conventional PCR was done for MexA (The Mex AB OprM operon resistance genes) and the O-antigen acetylase gene (the species-specific gene) separately, gave positive bands for 49 out of the 50 specimens. Our finding confirms the presence of the MexA gene (and hence most probably MexABOprM operon) in 49 out of 50 specimens of Pseudomonas aeruginosa. Conclusion: Among other resistance mechanisms to antibiotics and disinfectants, the MexABOprM efflux pump might have a role.

The Art of War with Pseudomonas aeruginosa: Targeting Mex Efflux Pumps Directly to Strategically Enhance Antipseudomonal Drug Efficacy

“…In clinical isolates, the concurrent mutational overexpression of specific major efflux pumps, such as MexAB-OprM combined with MexCD-OprJ or MexEF-OprN paired with MexXY, has been identified as a significant contributor to mutation-driven MDR [ 22 , 29 , 191 , 192 ]. Several studies have consistently indicated that the overexpression of MexAB-OprM and MexXY is frequently observed (ranging from 10% to 30%) in clinical isolates [ 33 , 97 , 139 , 158 , 176 , 193 , 194 , 195 ], highlighting their significant role in antibiotic resistance. Conversely, the occurrence of MexCD-OprJ and MexEF-OprN overexpression, as suggested by existing research, is comparatively uncommon, with a prevalence of less than 5% among clinical isolates [ 33 , 139 , 158 , 196 , 197 , 198 ].…”