title: Correlation between substitutions in penicillin-binding protein 1 and amoxicillin resistance in Helicobacter pylori.
abstract: The correlation between the substitutions of penicillin-binding protein 1 (PBP1) and amoxicillin resistance was studied for the determination of the substitutions in PBP1 which confer amoxicillin resistance in Helicobacter pylori. By the comparison of the amino acid sequences of PBP1 in the amoxicillinresistant (n=3), low-susceptible (n=3), and susceptible (n=13) H. pylori isolates, the substitution Asn562-->Tyr, which is adjacent to KTG motif (555-557), was common and specific to amoxicillin-resistant H. pylori. Additionally, all amoxicillin-resistant isolates had multiple substitutions such as Ser414-->Arg in the transpeptidase region of PBP1 of H. pylori. Furthermore all transformants obtained by the natural transformation using the pbp1 genes of amoxicillin-resistant H. pylori isolates had multiple substitutions including Asn562-->Tyr. These results suggest that multiple amino acid substitutions in the transpeptidase region of PBP1 are closely related to amoxicillin resistance in H. pylori.
authors.affiliation: Department of Microbiology, School of Pharmacy, Tokyo University of Pharmacy and Life Science, Hachioji-shi, Tokyo 192-0392, Japan..
authors.forename: Emiko
authors.initials: E
authors.lastname: Rimbara
authors.forename: Norihisa
authors.initials: N
authors.lastname: Noguchi
authors.forename: Takashi
authors.initials: T
authors.lastname: Kawai
authors.forename: Masanori
authors.initials: M
authors.lastname: Sasatsu
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000658:Amoxicillin / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D016481:Helicobacter Infections / Q000382:microbiology; D016480:Helicobacter pylori / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D010403:Penicillin Resistance / Q000235:genetics*; D046915:Penicillin-Binding Proteins / Q000737:chemistry / Q000235:genetics*; D010458:Peptidyl Transferases / Q000235:genetics; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D046915:Penicillin-Binding Proteins; D000658:Amoxicillin; D010458:Peptidyl Transferases; D001618:beta-Lactamases