title: Long-term persistence of ciprofloxacin-resistant Haemophilus influenzae in patients with cystic fibrosis.
abstract: Ciprofloxacin has been a major advance in the treatment of chronic respiratory infections. Three patients with cystic fibrosis and colonized by 5 nontypeable Haemophilus influenzae strains exhibiting low- (MIC, 2 microg/mL) and high-level ciprofloxacin resistance (MICs, 16-32 microg/mL) are described. The patients had received several courses of ciprofloxacin. These MICs represent a decrease in ciprofloxacin susceptibility of 200-3200 times. Molecular epidemiologic methods demonstrated that 2 patients were chronically colonized by their own ciprofloxacin-resistant strains for > or = 15-17 months. Three strains showed simultaneous resistance to ampicillin and chloramphenicol by enzyme inactivation, and 2 had ampicillin resistance without beta-lactamase activity. These data suggest that the emergence and long-term persistence of ciprofloxacin-resistant H. influenzae in patients with cystic fibrosis can be a consequence of antibiotic treatment.
authors.affiliation: Centro Nacional de Microbiologia, Majadahonda, Madrid, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Campos
authors.forename: F
authors.initials: F
authors.lastname: Román
authors.forename: M
authors.initials: M
authors.lastname: Georgiou
authors.forename: C
authors.initials: C
authors.lastname: García
authors.forename: R
authors.initials: R
authors.lastname: Gómez-Lus
authors.forename: R
authors.initials: R
authors.lastname: Cantón
authors.forename: H
authors.initials: H
authors.lastname: Escobar
authors.forename: F
authors.initials: F
authors.lastname: Baquero
mesh_terms: D000328:Adult; D000668:Ampicillin Resistance; D000890:Anti-Infective Agents / Q000627:therapeutic use*; D002702:Chloramphenicol Resistance; D002939:Ciprofloxacin / Q000627:therapeutic use*; D003550:Cystic Fibrosis / Q000382:microbiology*; D004352:Drug Resistance, Microbial; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D006192:Haemophilus Infections / Q000188:drug therapy*; D006193:Haemophilus influenzae / Q000187:drug effects / Q000254:growth & development; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D012150:Polymorphism, Restriction Fragment Length; D001618:beta-Lactamases / Q000378:metabolism
chemical_list: D000890:Anti-Infective Agents; D002939:Ciprofloxacin; D001618:beta-Lactamases