Synergistic effect of silver oxide nanoparticles and probiotic Lactobacillus plantarum on gene expression of MexX component of pump efflux system in drug-resistant Pseudomonas aeruginosa strains

Background &

An important part of drug resistance In Pseudomonas aeruginosa is    related to efflux pump systems. In this study, the antimicrobial effect of silver oxide nanoparticle and Lactobacillus plantarum probiotic on MexX gene expression has been studied.Materials &

In this descriptive cross-sectional study, 49 samples were collected from Mashhad and identified using standard methods. Strains with multidrug resistance were selected to determine MIC and check the frequency of MexX gene by PCR method. Broth dilution method was performed for probiotics, silver oxide nanoparticles and combination of both to obtain MIC and MBC. Microdilution method and Real time-PCR technique were used to determine the effective dilution of silver oxide nanoparticles and probiotics and MexX gene expression, respectively. The data related to the changes in MexX gene expression were analyzed by the 2-ΔΔCT  method using the independent T test in two groups.

All strains had MexX gene and all of them were resistant to more than two antibiotics. The minimum concentration of growth inhibition in the dilution method in agar was for silver oxide nanoparticles up to a dilution of 500 µg/ml and for probiotics up to a dilution of 16 µg/ml. Compared to probiotics, silver nanoparticles had a greater effect in inhibiting the growth of bacteria, and the amount of this effect is greater than the combined effect of probiotics and silver nanoparticles (P>0.05).

Silver oxide nanoparticle and probiotic have antibacterial effect to reduceMexXY-OprM efflux pump function in Pseudomonas aeruginosa bacteria.