Inhibition of the NorA efflux pump of Staphylococcus aureus by synthetic riparins

L. MURATORI COSTA; E. VERÇOSA DE M.; F. ARAÚJO DE A.O.; J.H. LIMA FERREIRA; S.J. CHAVEZ GUTIERREZ ; W.J. PELÁEZ ; F.C. ALVES LIMA; J. PINTO DE SIQUEIRA JR.; H.D. MELO COUTINHO; G.W. KAATZ; R. MENDES DE FREITAS; H. MEDEIROS BARRETO

JOURNAL OF APPLIED MICROBIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2016 vol. 121 p. 1312 - 1312

1364-5072

im: The goal of this study was to increase knowledge about the antimicrobialactivity of some synthetic Riparin-derived compounds, alone or incombination with fluoroquinolone antibiotics, against a strain of Staphylococcusaureus resistant to fluoroquinolone by way of overexpression of the NorAefflux pump.Methods and Results: Microdilution tests showed that Riparins A and B didnot show any significant antibacterial activity against Staph. aureus strains. On the other hand, the intrinsic antibacterial activity increased with increasing lipophilicity of the compounds, in the following order: Riparin-D (MIC 256 ug ml-1; Log P 2.95) < Riparin-C (MIC 102 ug ml-1; Log P 3.22) < Riparin-E (MIC 16 ug ml-1; Log P 3.57). The addition of all riparins to growth media at subinhibitory concentrations caused an increase in the antibacterial activity of antibiotics against the NorA-overexpressing test strain.Riparin-B, which has two methoxyl groups at the phenethyl moiety, showedthe best modulatory eff