title: Characterization of clinical isolates of Helicobacter pylori in Singapore.
abstract: Of the 69 Helicobacter pylori isolates analysed, 31 strains (45%) showed resistance to metronidazole, one strain (1.4%) was resistant to amoxicillin while two strains (2.9%) were resistant to clarithromycin. It was found that metronidazole resistance rates increased in Singapore from 20% to 62% between late 1995 and early 1997. By biotyping using API ZYM, a total of 80% (55/69) strains were characterized as biotype II, while the remaining 20% (14/69) strains belonged to biotype III. Interestingly, 71% (10/14) of biotype III were resistant to metronidazole compared with 38% (21/55) of biotype II. DNA profiles generated by random amplified polymorphic DNA from 69 isolates showed highly diversified DNA fingerprints allowing effective discrimination among strains. Of the 60 H. pylori isolates from peptic ulcer patients, it was found that cagA and vacA occurred in 80% (48/60) and 82% (49/60) isolates, respectively.
authors.affiliation: Department of Microbiology, National University of Singapore, Republic of Singapore.
authors.forename: J
authors.initials: J
authors.lastname: Hua
authors.forename: H C
authors.initials: HC
authors.lastname: Ng
authors.forename: K G
authors.initials: KG
authors.lastname: Yeoh
authors.forename: K Y
authors.initials: KY
authors.lastname: Ho
authors.forename: B
authors.initials: B
authors.lastname: Ho
mesh_terms: D000658:Amoxicillin / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000942:Antigens, Bacterial; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics; D015373:Bacterial Typing Techniques; D001706:Biopsy; D017291:Clarithromycin / Q000494:pharmacology; D003603:Cytotoxins / Q000737:chemistry / Q000235:genetics; D017931:DNA Primers / Q000737:chemistry; D004269:DNA, Bacterial / Q000737:chemistry; D004352:Drug Resistance, Microbial; D004587:Electrophoresis, Agar Gel; D016481:Helicobacter Infections / Q000453:epidemiology / Q000276:immunology / Q000382:microbiology*; D016480:Helicobacter pylori / Q000145:classification* / Q000187:drug effects / Q000276:immunology; D006801:Humans; D008795:Metronidazole / Q000494:pharmacology; D010406:Penicillins / Q000494:pharmacology; D010437:Peptic Ulcer / Q000453:epidemiology / Q000276:immunology / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D015995:Prevalence; D019105:Random Amplified Polymorphic DNA Technique; D012846:Singapore / Q000453:epidemiology; D013270:Stomach / Q000382:microbiology; D013753:Tetracycline Resistance
chemical_list: D000900:Anti-Bacterial Agents; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D003603:Cytotoxins; D017931:DNA Primers; D004269:DNA, Bacterial; D010406:Penicillins; C074689:VacA protein, Helicobacter pylori; C080866:cagA protein, Helicobacter pylori; D008795:Metronidazole; D000658:Amoxicillin; D017291:Clarithromycin