Comparison the effect of Curcumin and methanolic extracts of Fraxinus excelsior L. and glycyrrhiza glabra L. on the expression of MexCD-OprJ and MexEF-OprN efflux pumps in multidrug resistant Pseudomonas aeruginosa clinical isolates.

BACKGROUND

Pseudomonas aeruginosa is a multidrug-resistant (MDR) pathogen, and efflux pumps such as MexCD-OprJ and MexEF-OprN play a key role in its antibiotic resistance. This study evaluated the putative effects of curcumin and methanolic extracts of F. excelsior L. and G. glabra L. on the expression of these efflux pumps, as well as their role in mediating antibiotic resistance.

METHODS AND

RESULTS

In this study, MDR P. aeruginosa clinical strains were used to determine the minimum inhibitory concentrations (MICs) of tobramycin and ciprofloxacin in the presence and absence of curcumin and selected plant extracts (F. excelsior L. and G. glabra L.) and curcumin. Real-time PCR was used to assess changes in efflux pump gene expression in tested strains. A significant positive correlation was identified between resistance to the tested antibiotics and increased expression of MexCD-OprJ and MexEF-OprN, as determined by Spearman's rank correlation using SPSS (p < 0.05). Treatment with the extracts, individually and in combination, resulted in a reduction in the expression levels of both efflux genes (p < 0.05), with the combined treatment showing the greatest effect. These findings were supported by colony count and turbidity assays, as evidenced by > 80% reduction in viable counts and decreased turbidity in treated groups.

CONCLUSION

Overexpression of MexCD-OprJ and MexEF-OprN is a key factor contributing to MDR in P. aeruginosa. Treatment with curcumin, F. excelsior L. and G. glabra L. extracts-especially in combination, suggesting potential for suppression of efflux gene expression and enhanced antibiotic efficacy.