title: Growth competition of macrolide-resistant and -susceptible Helicobacter pylori strains.
abstract: We examined population dynamics in a mixed culture of clonally related macrolide-resistant and -susceptible Helicobacter pylori strains isolated from a single patient. The resistant strain had a macrolide resistance-conferring A2143G mutation in the 23S rRNA gene. The growth rate of these two strains did not apparently differ when cultured separately. On the other hand, by conducting sequential passage of a mixed culture of the resistant and the susceptible strains, the ratio of the resistant strain to the susceptible strain in the culture typically decreased per passage, indicating that the resistance imposed a significant disadvantage on bacterial fitness in the population.
authors.affiliation: Department of Bacterial Pathogenesis and Infection Control, National Institute of Infectious Diseases, Musashimurayama, Tokyo 208-0011, Japan.
authors.forename: Kyoko
authors.initials: K
authors.lastname: Kanai
authors.forename: Keigo
authors.initials: K
authors.lastname: Shibayama
authors.forename: Satowa
authors.initials: S
authors.lastname: Suzuki
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Wachino
authors.forename: Yoshichika
authors.initials: Y
authors.lastname: Arakawa
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D001483:Base Sequence; D017291:Clarithromycin / Q000494:pharmacology*; D002999:Clone Cells; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D024881:Drug Resistance, Bacterial; D016481:Helicobacter Infections / Q000382:microbiology; D016480:Helicobacter pylori / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development*; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D010437:Peptic Ulcer / Q000382:microbiology; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D012338:RNA, Ribosomal, 23S / Q000737:chemistry / Q000235:genetics
chemical_list: D000890:Anti-Infective Agents; D004269:DNA, Bacterial; D012338:RNA, Ribosomal, 23S; D017291:Clarithromycin