title: Fluoroquinolone resistance in Haemophilus influenzae is associated with hypermutability.
abstract: Forty-three percent (12/28) of ciprofloxacin (CIP)-nonsusceptible respiratory isolates of Haemophilus influenzae were hypermutable, compared with 8.5% (3/35) in the CIP-susceptible control group (P=0.002). CIP-nonsusceptible mutants were obtained with hypermutable strains only; these mutants developed three resistance mechanisms in a step-by-step process: target modifications, loss of a porin protein, and increased efflux.
authors.affiliation: Antibiotic Laboratory, Bacteriology Service, Centro Nacional de Microbiología, Instituto de Salud Carlos III, 28220 Majadahonda, Madrid, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Pérez-Vázquez
authors.forename: Federico
authors.initials: F
authors.lastname: Román
authors.forename: Silvia
authors.initials: S
authors.lastname: García-Cobos
authors.forename: José
authors.initials: J
authors.lastname: Campos
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D024841:Fluoroquinolones / Q000494:pharmacology*; D005798:Genes, Bacterial / Q000235:genetics; D006192:Haemophilus Infections / Q000382:microbiology; D006193:Haemophilus influenzae / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D008826:Microbial Sensitivity Tests; D009154:Mutation / Q000187:drug effects / Q000235:genetics*
chemical_list: D000890:Anti-Infective Agents; D024841:Fluoroquinolones