Assessment of Efflux Pump Activity and Screened the Prevalence of Associated Genes Mex A and B among MDR Pseudomonas aeruginosa Isolates

Abstract

Efflux pumps play a critical role in the biology of Pseudomonas aeruginosa,  These pumps are membrane-bound transport systems that actively expel various substances, including antibiotics, toxic compounds, and metabolic byproducts, out of the bacterial cell.  The aim of research to detect the presence of efflux pump genes Mex A and Mex B  Pseudomonas aeruginosa isolated from different sources. One hundred samples were taken from male and female patients within four age groups (1-9, 10-29, 30-50 and < 50 ) . The study revealed that 50% of samples were positive to P. aeruginosa with no significant variation among gender and age groups but there was a little higher rate in the young people group than older people group. The isolates subjected to measure the biofilm production ability and results revealed there were 39 (78%) out of 50 isolate confirmed as P. aeruginosa strong biofilm formation while the rest isolates were showed weak and moderate production of biofilm. The antibiotic sensitivity test was done using the disc diffusion method for all Fifty strain which shows very high resistance to selected antibiotics, especially Piperacillin and Ticarcillin-clavulanate, the most antibiotic-effective bacterial growth was Piperacillin-tazobactam.  Phenotypic detection of efflux pump activity was done using the ethidium bromide cartwheel method and revealed that 32 (17 isolate positive for all concentration; 15 isolates positive against different concentration) (64%) of examined isolates were positive to efflux pump in all concentrations of ethidium bromide dye. While 18 (36%) isolates were inactive for the efflux pump in all concentrations. Ten efflux pump positive isolates were selected for molecular detection. The result of the molecular study using conventional PCR detection for Mex A and Mex B genes shows that all ten-isolate have  efflux pump genes.