Open AccessEfflux Pump-Mediated Quinolone Resistance in Staphylococcus aureus Strains Wild Type for gyrA , gyrB , grlA , and norA
Author(s) -
Juan Luis Muñoz Bellido,
Miguel Manzanares,
Jonathan Andrés,
Ma Nieves Gutiérrez Zufiaurre,
Guadalupe Ortiz,
M. Segovia Hernández,
J.Á. García-Rodríguez
Publication year - 1999
Publication title -
antimicrobial agents and chemotherapy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.07
H-Index - 259
eISSN - 1070-6283
pISSN - 0066-4804
DOI - 10.1128/aac.43.2.354
Subject(s) - efflux , staphylococcus aureus , quinolone , microbiology and biotechnology , ciprofloxacin , biology , antibacterial agent , antibiotics , bacteria , chemistry , genetics
Fluoroquinolone efflux was studied in 47Staphylococcus aureus clinical strains with MICs of ciprofloxacin (CFX) of ≤2 μg/ml. Forty-three strains were wild type forgyrA ,gyrB , andgrlA quinolone resistance-determining regions and fornorA and its promoter region. Forty of these strains (MICs of CFX, 0.1 to 0.2 μg/ml) did not show efflux of fluoroquinolones. Three strains (MICs of CFX, 1 to 2 μg/ml) showed efflux. These results suggest that efflux can appear inS. aureus clinical strains in the absence of mutations innorA and its promoter.