Antimicrobial activity of polypyrrole nanoparticles and aqueous extract of Moringa oleifera against Staphylococcus spp. carriers of multi-drug efflux system genes isolated from dairy farms

Our objectives were to identify genes of the multi-drug efflux system and to evaluate the antimicrobial activities of polypyrrole nanoparticles (PPy-NPs) and aqueous extract ofMoringa oleiferaagainstStaphylococcusspp. isolated from dairy farms in Northeast Brazil. Initially, 162Staphylococcusspp. isolates were subjected toin vitroantimicrobial sensitivity tests. Of these, 35 presented antimicrobial multi-drug resistance phenotypes. These 35 isolates were then referred for the detection ofnorA, norB, norC, msrA, mgrA, tet-38,andlmrSgenes, all of which feature in multi-drug efflux systems. In the isolates carrying the genes, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of PPy-NPs andMoringa oleiferaaqueous extract were determined. In the molecular analysis of the 35 isolatesnorA, norC, tet-38,andmsrAgenes were detected and for the other genesnorB, lmrSandmgrAthere was no amplification. Antimicrobial activity was verified of PPy-NPs and aqueous extract ofMoringa oleiferainStaphylococcusspp. carrying multi-drug efflux system genes. We concluded that there are multi-drug efflux system genes present in theStaphylococcusspp. from the agricultural environment in Northeast Brazil, and that aqueous extract ofMoringa oleiferaand PPy-NPs show bactericidal activity against these isolates.