title: [Comparative bacteriologic activity of norfloxacin, ofloxacin and pefloxacin against 320 Gram-negative bacilli resistant and non-resistant to nalidixic acid and cephalosporins].
abstract: Bacteriostatic and bactericidal effects of three fluoroquinolones, norfloxacin, ofloxacin and pefloxacin, against 320 strains of Gram-negative bacilli were studied in vitro. For nalidixic acid-susceptible Enterobacteriaceae, susceptibility or resistance to second or third generation cephalosporins has no significant bearing on the MIC 90 of each of the three antibiotics. This is not so of nalidixic acid-resistant strains. All E. coli and K. pneumoniae strains are susceptible to the three quinolones (MIC 90 less than 3 mg/1); MICs 90 are higher for E. cloacae and S. marcescens; Serratia strains in particular have an MIC 90 greater than 6 mg/1. Nalidixic acid-susceptible Acinetobacter strains can be eliminated by ofloxacin or pefloxacin, whereas norfloxacin has the greatest activity against P. aeruginosa. We conclude that when multiresistant bacteria emerge, testing of susceptibility to the three quinolones studied may be useful.
mesh_terms: D000150:Acinetobacter / Q000187:drug effects; D002511:Cephalosporins / Q000494:pharmacology*; D004352:Drug Resistance, Microbial; D004755:Enterobacteriaceae / Q000187:drug effects; D006090:Gram-Negative Bacteria / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D009268:Nalidixic Acid / Q000494:pharmacology*; D009643:Norfloxacin / Q000031:analogs & derivatives* / Q000494:pharmacology*; D015242:Ofloxacin; D010078:Oxazines / Q000494:pharmacology*; D015366:Pefloxacin; D011550:Pseudomonas aeruginosa / Q000187:drug effects
chemical_list: D002511:Cephalosporins; D010078:Oxazines; D015366:Pefloxacin; D009268:Nalidixic Acid; D015242:Ofloxacin; D009643:Norfloxacin
vernacular_title: Activité bactériologique comparée de norfloxacine, ofloxacine, péfloxacine vis-à-vis de 320 bacilles gram négatif résistants ou non à l'acide nalidixique et aux céphalosporines.