[In vitro activity of 4 fluoroquinolones against Klebsiella pneumoniae. Distribution according to phenotype resistance to aminoglycosides or beta-lactams].
Minimal inhibitory concentrations (MIC) of pefloxacin (PEF), norfloxacin (NOR), ofloxacin (OFL) and ciprofloxacin (CIP) are evaluated by agar dilution against 100 Klebsiella pneumoniae strains isolated in hospital. MIC 50 and 90%, micrograms/ml, are respectively: CIP (0.25/8), OFL (1/16), NOR (1/32), PEF (2/64). We determined the phenotypes PEF/NOR/OFL/CIP by taking into account the critic concentrations of the French Committee for Antibiogram. The results are: SSSS = 45%, RI/RI/RI/RI = 20%, RI/SSS = 19%, RI/RI/RI/S = 8%, RI/RI/SS = 7%. When a strain is resistant to pefloxacin alone, the MICs of the other fluoroquinolones are higher than those of the sensitive strains. The resistance to fluoroquinolones is most frequent in strains that have acquired resistance to aminoglycosides or betalactams, but exists also in strains that have no acquired resistance to these antibiotics.
Laboratoire de Microbiologie, Hôpital Raymond Poincaré, Garches.
M L
ML
Miguères
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E
Ronco
M
M
Guenounou
D000617:Aminoglycosides; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002939:Ciprofloxacin / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004352:Drug Resistance, Microbial; D066298:In Vitro Techniques; D007711:Klebsiella pneumoniae / Q000187:drug effects*; D009643:Norfloxacin / Q000494:pharmacology*; D015242:Ofloxacin / Q000494:pharmacology*; D015366:Pefloxacin / Q000494:pharmacology*; D010641:Phenotype; D047090:beta-Lactams
D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D047090:beta-Lactams; D015366:Pefloxacin; D002939:Ciprofloxacin; D015242:Ofloxacin; D009643:Norfloxacin
Activité in vitro de quatre fluoroquinolones sur Klebsiella pneumoniae. Répartition selon les phénotypes de résistance aux aminosides et aux bêta-lactamines.