Open AccessSusceptibility of Xanthomonas maltophilia to six quinolones and study of outer membrane proteins in resistant mutants selected in vitro
Author(s) -
Marylin Lecsö-Bornet,
Josiane Pierre,
Dolla Sarkis-Karam,
S Lubera,
E Bergogne-Bérézin
Publication year - 1992
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.36.3.669
Subject(s) - nalidixic acid , microbiology and biotechnology , xanthomonas , mutant , bacterial outer membrane , biology , antibacterial agent , cross resistance , chloramphenicol , dna gyrase , quinolone , minimum inhibitory concentration , bacteria , antibiotics , antibiotic resistance , biochemistry , escherichia coli , gene , genetics
The in vitro susceptibilities of 75 clinical isolates of Xanthomonas maltophilia to nalidixic acid, five fluoroquinolones, latamoxef, and doxycycline were determined. Spontaneous mutants were selected, at a frequency of about 10(-5) to 10(-7) from four strains by culturing the strains in the presence of each quinolone. Selection in the presence of nalidixic acid provided mutants that were either resistant only to that compound or that exhibited cross-resistance to all the fluoroquinolones tested. Cross-resistance was always observed for mutants selected on any of the five fluoroquinolones. It was always associated with chloramphenicol resistance and, frequently, with doxycycline resistance. The electrophoretic alterations of the outer membrane proteins of the mutants suggest that different mechanisms may be involved in quinolone resistance in X. maltophilia.