title: Effect of fluoroquinolone resistance selection on the fitness of three strains of Clostridium perfringens.
abstract: Selection of bacterial strains for resistance to antimicrobial agents may affect fitness; and fluoroquinolone resistance has been shown to affect fitness of aerobic and facultative bacteria. The impact on bacterial fitness of resistance selection to three fluoroquinolones was examined in three wild-type strains of Clostridium perfringens: ATCC 13124, ATCC 3626, and NCTR. Selection for resistance to norfloxacin, ciprofloxacin, and gatifloxacin affected the fitness of nine mutant strains differently. In a series of pure cultures grown in the absence of drugs, the growth of each of the mutants was comparable to that of the corresponding wild type. In competition experiments between mutants and isogenic wild types, however, some of the mutants were less fit. The fitness of ciprofloxacin-resistant mutants was comparable for all three strains, but two gatifloxacin-resistant mutants and one norfloxacin-resistant mutant were significantly less fit than the corresponding wild types. We conclude that both the genetic background of the strain and the fluoroquinolone which induced resistance affected the fitness of the resistant mutants. This is the first time that the effect on fitness of resistance to antimicrobial agents has been measured for C. perfringens.
authors.affiliation: Division of Microbiology, National Center for Toxicological Research , U.S. Food and Drug Administration, Jefferson, Arkansas.
authors.forename: Miseon
authors.initials: M
authors.lastname: Park
authors.forename: John B
authors.initials: JB
authors.lastname: Sutherland
authors.forename: Jong Nam
authors.initials: JN
authors.lastname: Kim
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Rafii
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002939:Ciprofloxacin / Q000494:pharmacology*; D003016:Clostridium perfringens / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development; D024881:Drug Resistance, Bacterial / Q000235:genetics; D024841:Fluoroquinolones / Q000494:pharmacology*; D000077734:Gatifloxacin; D056084:Genetic Fitness / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects; D009154:Mutation; D009643:Norfloxacin / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; D002939:Ciprofloxacin; D000077734:Gatifloxacin; D009643:Norfloxacin