title: Comparative study of the mutant prevention concentrations of moxifloxacin, levofloxacin, and gemifloxacin against pneumococci.
abstract: We tested the propensity of three quinolones to select for resistant Streptococcus pneumoniae mutants by determining the mutant prevention concentration (MPC) against 100 clinical strains, some of which harbored mutations in type II topoisomerases. Compared with levofloxacin and gemifloxacin, moxifloxacin had the lowest number of strains with MPCs above the susceptibility breakpoint (P<0.001), thus representing a lower selective pressure for proliferation of resistant mutants. Only moxifloxacin gave a 50% MPC (MPC50) value (1 microg/ml) within the susceptible range.
authors.affiliation: Department of Pathology, Hershey Medical Center, P.O. Box 850, Hershey, PA 17033, USA.
authors.forename: Kim
authors.initials: K
authors.lastname: Credito
authors.forename: Klaudia
authors.initials: K
authors.lastname: Kosowska-Shick
authors.forename: Pamela
authors.initials: P
authors.lastname: McGhee
authors.forename: Glenn A
authors.initials: GA
authors.lastname: Pankuch
authors.forename: Peter C
authors.initials: PC
authors.lastname: Appelbaum
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001372:Aza Compounds / Q000494:pharmacology*; D004250:DNA Topoisomerases, Type II / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000235:genetics; D024841:Fluoroquinolones / Q000494:pharmacology*; D000077735:Gemifloxacin; D064704:Levofloxacin; D008826:Microbial Sensitivity Tests; D000077266:Moxifloxacin; D009154:Mutation; D009287:Naphthyridines / Q000494:pharmacology*; D015242:Ofloxacin / Q000494:pharmacology*; D016133:Polymerase Chain Reaction; D011804:Quinolines / Q000494:pharmacology*; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D001372:Aza Compounds; D024841:Fluoroquinolones; D009287:Naphthyridines; D011804:Quinolines; D064704:Levofloxacin; D015242:Ofloxacin; D004250:DNA Topoisomerases, Type II; D000077735:Gemifloxacin; D000077266:Moxifloxacin