Synergistic Effect of Silver Nanoparticles and Probiotic Lactobacillus Plantarum on the Expression of Mexa Component Gene of Pump Efflux System in Drug-Resistant Pseudomonas Aeruginosa Isolates

At present, Pseudomonas aeruginosa bacteria has caused many problems to control nosocomial infections due to its resistance to various antibiotics and MexAB-OprM efflux pumps play an important role in making Pseudomonas aeruginosa strains resistant to antibiotics. The aim of this study was to determine the antimicrobial effect of silver nanoparticles and probiotic Lactobacillus plantarum on MexA gene expression.

In this descriptive cross-sectional study, 49 strains were collected from 8 medical diagnostic laboratories in Mashhad during the years 1398-1399 for 8 months. Evaluation of antibiotic susceptibility pattern of strains was using disk diffusion method based on CLSI protocol. After treatment of multidrug resistant bacteria with inhibitors, microdilution method and Real time-PCR technique were used to determine the effective dilution of silver nanoparticles and probiotics on the expression of MexA gene of its producing bacterium, respectively.

All samples were identified and all of them were resistant to more than two antibiotics and had MexA gene. The minimum growth inhibition concentration in agar dilution method was up to 250 μg / ml for silver nanoparticles and up to 18 μg / ml for probiotics. Silver nanoparticles had a greater effect in inhibiting bacterial growth compared to probiotics and this effect is less than the combined effect of probiotics and silver nanoparticles (P> 0.05).

Silver and probiotic nanoparticles have inhibitory and antibacterial activity to reduce the performance of MexAB-OprM efflux pump in Pseudomonas aeruginosa. (P> 0.05).