title: cagA gene variants in Malaysian Helicobacter pylori strains isolated from patients of different ethnic groups.
abstract: Helicobacter pylori infection of a distinct subtype of cagA may lead to different pathological manifestation. The aim of this study is to determine the presence of cagA gene and its variants in H. pylori infection among different ethnic groups and its effect on gastroduodenal diseases. Overall detection of cagA among the 205 clinical isolates of H. pylori was 94%. Variations in size of the 3' region of cagA gene were examined among 192 Malaysian H. pylori cagA-positive strains. Results showed that three cagA variants differing in fragment length of PCR products were detected and designated as type A (621-651bp), type B (732-735bp) and type C (525 bp). Although there was no association between any of the cagA subtypes with peptic ulcer disease (p>0.05), an association between cagA subtypes with a specific ethnic group was observed. Specific-cagA subtype A strains were predominantly isolated from Chinese compared to Malays and Indians (p<0.0005), and cagA subtype B strains were predominantly isolated from Malays and Indians compared to Chinese (p<0.05). The cagA type A strains of H. pylori is commonly found in the Chinese patients who have a higher risk of peptic ulcer disease, thus indicating that it could be used as an important clinical biomarker for a more severe infection.
authors.affiliation: Universiti Kebangsaan Malaysia Molecular Biology Institute, 7th Floor, Clinical Block, Hospital UKM, Jalan Yaacob Latif, Bandar Tun Razak, Cheras, 56000 Kuala Lumpur, Malaysia. ramelah@mail.hukm.ukm.my
authors.forename: Mohamed
authors.initials: M
authors.lastname: Ramelah
authors.forename: Ahmad
authors.initials: A
authors.lastname: Aminuddin
authors.forename: Hanafiah
authors.initials: H
authors.lastname: Alfizah
authors.forename: Mohd Rose
authors.initials: MR
authors.lastname: Isa
authors.forename: Ali Yaakob
authors.initials: AY
authors.lastname: Jasmi
authors.forename: Huck Joo
authors.initials: HJ
authors.lastname: Tan
authors.forename: A Jamal A
authors.initials: AJ
authors.lastname: Rahman
authors.forename: Abdul Manap
authors.initials: AM
authors.lastname: Rizal
authors.forename: M Zawawi
authors.initials: MZ
authors.lastname: Mazlam
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000942:Antigens, Bacterial / Q000235:genetics*; D044466:Asian People; D001426:Bacterial Proteins / Q000235:genetics*; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D016481:Helicobacter Infections / Q000453:epidemiology / Q000208:ethnology* / Q000382:microbiology; D016480:Helicobacter pylori / Q000145:classification* / Q000235:genetics; D006801:Humans; D008296:Malaysia / Q000453:epidemiology / Q000208:ethnology; D008297:Male; D008875:Middle Aged; D010437:Peptic Ulcer / Q000453:epidemiology / Q000208:ethnology* / Q000382:microbiology
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C080866:cagA protein, Helicobacter pylori