Antimicrobial activity of polypyrrole nanoparticles and aqueous extract ofMoringa oleiferaagainstStaphylococcusspp. carriers of multi-drug efflux system genes isolated from dairy farms

Abstract

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 of Moringa oleifera against Staphylococcus spp. isolated from dairy farms in Northeast Brazil. Initially, 162 Staphylococcus spp. isolates were subjected to in vitro antimicrobial sensitivity tests. Of these, 35 presented antimicrobial multi-drug resistance phenotypes. These 35 isolates were then referred for the detection of norA, norB, norC, msrA, mgrA, tet-38, and lmrS genes, 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 and Moringa oleifera aqueous extract were determined. In the molecular analysis of the 35 isolates norA, norC, tet-38, and msrA genes were detected and for the other genes norB, lmrS and mgrA there was no amplification. Antimicrobial activity was verified of PPy-NPs and aqueous extract of Moringa oleifera in Staphylococcus spp. carrying multi-drug efflux system genes. We concluded that there are multi-drug efflux system genes present in the Staphylococcus spp. from the agricultural environment in Northeast Brazil, and that aqueous extract of Moringa oleifera and PPy-NPs show bactericidal activity against these isolates.

Genetic and Phenotypic Characterization of Subclinical Mastitis-Causing Multidrug-Resistant Staphylococcus aureus

“…The bacterial efflux pump is another significant mechanism of antibiotic resistance, which is a major determinant of intrinsic and/or acquired resistance [ 7 ]. Silva et al [ 27 ] reported the presence of norA , norC , tet38 , and msrA genes in their S. aureus isolates. According to these results, isolates with molecular mechanisms of resistance to quinolones (e.g., norA and norC genes), tetracyclines (e.g., tet38 gene), and macrolides (e.g., msrA gene) circulated in their studied farms, and these genes can play a role in multidrug resistance.…”

“…The relative expression of norC is also found to be up-regulated during S. aureus biofilm growth [ 28 ]. The tet38 gene can help with the extrusion of antibiotics and can also support the survival and replication of staphylococci inside the host cells [ 27 ].…”

Efficacy assessment of an intramammary formulation based on soluble polypyrrole in cows with experimentally induced mastitis

“…The antimicrobial behavior of soluble polypyrrole against S. aureus isolates from mastitis cases has also been evaluated in previous studies, with satisfactory results characterized by low Minimum Inhibitory Concentration (MIC) values (ACOSTA et al, 2020;SILVA et al, 2020). From this perspective, this study aimed to evaluate the efficacy of an intramammary formulation based on soluble polypyrrole in cows affected by experimentally induced mastitis caused by S. aureus.…”

“…A number of studies have already verified the in vitro antimicrobial activity of polypyrrole against S. aureus isolates (ACOSTA et al, 2020;SILVA et al, 2020). However, it is well known that in vitro antimicrobial activity does not imply in vivo efficacy since drug action within bovine mammary glands depends on various pharmacokinetic characteristics of the formulation tested (PYÖRÄLÄ, 2009).…”