[Decrease in bactericidal activity of ciprofloxacin in Salmonella mutants generated following repeated exposure to various fluorquinolones].
Salmonella mutants with reduced fluoroquinolone susceptibility were generated in vitro following repeated exposure to subinhibitory concentrations of the drugs and the alterations in the gyrA gene were characterized. Afterwards, the change in bactericidal activity exhibited by ciprofloxacin against the resulting mutants was determined. A decrease in the bactericidal activity of ciprofloxacin was found in all the mutants, but was more pronounced in mutants of nalidixic acid-resistant strains. This may help to explain the therapeutic failures sometimes described when fluoroquinolones are used in the treatment of these strains. In addition, our model evaluates the first interactions produced between the microorganism and the antibiotics, and demonstrates that the loss of bactericidal activity of ciprofloxacin occurs following exposure to all of the fluoroquinolones tested.
Cebrián
L
L
Servicio de Microbiología, Hospital General Universitario de Elche, Universidad Miguel Hernández, Elche, Alicante.
Rodríguez
J C
JC
Escribano
I
I
Ruiz
M
M
Royo
G
G
D001426:Bacterial Proteins / Q000235:genetics* / Q000502:physiology; D002939:Ciprofloxacin / Q000494:pharmacology*; D027081:DNA Gyrase / Q000235:genetics* / Q000502:physiology; D027101:DNA Topoisomerase IV / Q000235:genetics* / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D004351:Drug Resistance / Q000235:genetics / Q000502:physiology*; D024841:Fluoroquinolones / Q000494:pharmacology*; D009268:Nalidixic Acid / Q000494:pharmacology; D012475:Salmonella / Q000187:drug effects* / Q000235:genetics; D012477:Salmonella enteritidis / Q000187:drug effects / Q000235:genetics; D012486:Salmonella typhimurium / Q000187:drug effects / Q000235:genetics; D012641:Selection, Genetic
D001426:Bacterial Proteins; D024841:Fluoroquinolones; D009268:Nalidixic Acid; D002939:Ciprofloxacin; D027101:DNA Topoisomerase IV; D027081:DNA Gyrase