Effect of the inhibitors phenylalanine arginyl ß-naphthylamide (PAßN) and 1-(1-naphthylmethyl)-piperazine (NMP) on expression of genes in multidrug efflux systems of Escherichia coli isolates from bovine mastitis

• Published in: Research in veterinary science Vol. 97; no. 2; pp. 176 - 181
• Main Authors: Ospina Barrero, M.A., Pietralonga, P.A.G., Schwarz, D.G.G., Silva Junior, A., Paula, S.O., Moreira, M.A.S.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.10.2014
• Subjects: Ampicillin - pharmacology; Animals; Anti-Infective Agents - pharmacology; Antimicrobial; Bacterial Proteins - antagonists & inhibitors; Bacterial Proteins - drug effects; Bacterial Proteins - genetics; Cattle; Colony Count, Microbial; Dipeptides - pharmacology; Drug Resistance, Multiple, Bacterial - genetics; Escherichia coli - drug effects; Escherichia coli - genetics; Escherichia coli - isolation & purification; Female; Gene Expression Regulation, Bacterial - drug effects; Mastitis, Bovine - drug therapy; Mastitis, Bovine - microbiology; Membrane Transport Proteins - drug effects; Membrane Transport Proteins - genetics; Microbial Sensitivity Tests - methods; Microbial Sensitivity Tests - veterinary; Milk; Multiresistant bacteria; Piperazines - pharmacology; Polymerase Chain Reaction; Therapy; Trimethoprim, Sulfamethoxazole Drug Combination - pharmacology; Antimicrobial; Therapy; Multiresistant bacteria; Milk
• ISSN: 0034-5288; 1532-2661
• DOI: 10.1016/j.rvsc.2014.05.013

•Four resistant E. coli isolates to two antibiotics simultaneously were used.•Two efflux pump inhibitors were evaluated on the multidrug efflux gene expression.•acrA and acrB had the lowest while emrA or emrB had the highest expression levels.•Efflux pump inhibitors decrease arcF expression when used with ampicillin treatment.•PAßN may serve as an alternative to assist in the antimicrobial therapy of mastitis. The multidrug efflux system in bacteria can reduce antibiotic concentration inside the cell, leading to failure in the treatment of bacterial diseases. This study evaluated the influence of two efflux pump inhibitors (EPIs), phenylalanine arginyl ß-naphthylamide (PAßN) and 1-(1-naphthylmethyl)-piperazine (NMP), on the gene expression of three multidrug efflux systems, AcrAB, AcrEF and EmrAB in Escherichia coli bovine mastitis isolates resistant to ampicillin and sulfamethoxazole/trimethoprim simultaneously. Each isolate had at least three multidrug efflux system genes. The acrA and acrB had the lowest expression levels in all treatments, while the emrA or emrB showed the highest expression levels in the presence of ampicillin, sulfamethoxazole/trimethoprim, PAβN and NMP. EPIs also contributed to the decrease in arcF expression when used in combination with ampicillin treatment. Since PAßN showed stronger effects than NMP, it may serve as an alternative to assist in the antimicrobial therapy of mastitis.