title: Helicobacter pylori vacA Genotypes in Chronic Gastritis and Gastric Carcinoma Patients from Macau, China.
abstract: Helicobacter pylori is the major triggering factor for gastric carcinoma, but only a small proportion of infected patients develop this disease. Differences in virulence observed among H. pylori strains, namely in the vacuolating cytotoxin vacA gene, may contribute to this discrepancy. Infection with vacA s1, i1 and m1 strains increases the risk for progression of gastric premalignant lesions and for gastric carcinoma. However, in East Asian countries most of the H. pylori strains are vacA s1, regardless of the patients' clinical status, and the significance of the vacA i1 and m1 genotypes for gastric carcinoma in this geographic area remains to be fully elucidated. The aim of the present study was to investigate this relationship in 290 patients from Macau, China. Using very sensitive and accurate genotyping methods, we detected infection with vacA i1 and with vacA m1 strains in, respectively, 85.2% and 52.6% of the patients that were infected with single genotypes. The prevalence of cagA-positive strains was 87.5%. No significant associations were observed between vacA genotypes or cagA and gastric carcinoma. It is worth noting that 37.5% of the infected patients had coexistence of H. pylori strains with different vacA genotypes. Additional studies directed to other H. pylori virulence factors should be performed to identify high risk patients in East Asia.
authors.affiliation: i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto 4200-135, Portugal. iribeiro@ipatimup.pt.|Ipatimup-Institute of Molecular Pathology and Immunology of the University of Porto, Porto 4200-135, Portugal. iribeiro@ipatimup.pt.
authors.forename: Ines
authors.initials: I
authors.lastname: Pinto-Ribeiro
authors.affiliation: i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto 4200-135, Portugal. ruif@ipatimup.pt.|Ipatimup-Institute of Molecular Pathology and Immunology of the University of Porto, Porto 4200-135, Portugal. ruif@ipatimup.pt.
authors.forename: Rui M
authors.initials: RM
authors.lastname: Ferreira
authors.affiliation: Centro Hospitalar Conde São Januário, Macau, China. batalhacosi1210@yahoo.co.uk.
authors.forename: Sellma
authors.initials: S
authors.lastname: Batalha
authors.affiliation: Centro Hospitalar Conde São Januário, Macau, China. thazin@macau.ctm.net.
authors.forename: Thazin
authors.initials: T
authors.lastname: Hlaing
authors.affiliation: Centro Hospitalar Conde São Januário, Macau, China. siwong2004@ssm.gov.mo.
authors.forename: Sio In
authors.initials: SI
authors.lastname: Wong
authors.affiliation: i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto 4200-135, Portugal. fcarneiro@ipatimup.pt.|Ipatimup-Institute of Molecular Pathology and Immunology of the University of Porto, Porto 4200-135, Portugal. fcarneiro@ipatimup.pt.|Department of Pathology and Oncology, Faculty of Medicine of the University of Porto, Porto 4200-319, Portugal. fcarneiro@ipatimup.pt.|Department of Pathology, Centro Hospitalar São João, Porto 4200-319, Portugal. fcarneiro@ipatimup.pt.
authors.forename: Fatima
authors.initials: F
authors.lastname: Carneiro
authors.affiliation: i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto 4200-135, Portugal. cfigueiredo@ipatimup.pt.|Ipatimup-Institute of Molecular Pathology and Immunology of the University of Porto, Porto 4200-135, Portugal. cfigueiredo@ipatimup.pt.|Department of Pathology and Oncology, Faculty of Medicine of the University of Porto, Porto 4200-319, Portugal. cfigueiredo@ipatimup.pt.
authors.forename: Ceu
authors.initials: C
authors.lastname: Figueiredo
mesh_terms: D000368:Aged; D001426:Bacterial Proteins / Q000235:genetics*; D001427:Bacterial Toxins / Q000235:genetics; D002681:China / Q000453:epidemiology; D002908:Chronic Disease; D004269:DNA, Bacterial / Q000235:genetics; D005260:Female; D005756:Gastritis / Q000453:epidemiology / Q000382:microbiology* / Q000473:pathology; D005798:Genes, Bacterial; D005838:Genotype; D016481:Helicobacter Infections / Q000453:epidemiology / Q000382:microbiology* / Q000473:pathology; D016480:Helicobacter pylori / Q000235:genetics* / Q000472:pathogenicity; D006801:Humans; D008297:Male; D008875:Middle Aged; D013274:Stomach Neoplasms / Q000453:epidemiology / Q000382:microbiology* / Q000473:pathology; D014774:Virulence
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004269:DNA, Bacterial; C074689:VacA protein, Helicobacter pylori
keywords: China; Helicobacter pylori; gastric carcinoma; genotyping; vacA gene