Clinical relevance of the cagA, vacA and iceA genotypes of Helicobacter pylori in Brazilian clinical isolates.
Infection with Helicobacter pylori strains harboring determinants of pathogenicity may lead to a strong inflammatory response in gastric mucosa. In this work, we examined the frequency of the cagA, vacA and iceA genotypes in H. pylori strains isolated from Brazilian patients and correlated these with the clinical manifestations. H. pylori was isolated from 165 patients [30 with non-ulcer dyspepsia cases (NUD); 93 peptic ulcer disease (PUD): 31 gastric ulcers (GU) and 62 duodenal ulcer disease (DU); 18 with erosive gastritis (EG); and 24 gastroesophageal reflux disease (GERD)]. Allelic variants of cagA, vacA and iceA were identified using the polymerase chain reaction. More than one H. pylori strain was detected in 28 cases (17%), and these were excluded from the statistical analysis. We were unable to confirm an association between iceA status and clinical outcome. There was a strong association between the genotype cagA-positive vacA s1 and PUD. However, logistic regression analysis showed that vacA s1 was the only predictive factor for PUD (OR=4.19; 95% CI 1.95-8.98). The presence of the less virulent strain vacA s2 was related to GERD (OR=8.59; 95% CI 2.85-25.91). Our results support the hypothesis that virulent strains may protect against the development of GERD.
Clinical Pharmacology and Gastroenterology Unit, São Francisco University Medical School, Av. São Francisco de Assis, 218, 12916-900 Bragança Paulista, SP, Brazil.
Marcelo Lima
ML
Ribeiro
Anita Paula Ortiz
AP
Godoy
Yune Helena Borges
YH
Benvengo
Sergio
S
Mendonça
José
J
Pedrazzoli
D000328:Adult; D000942:Antigens, Bacterial / Q000235:genetics; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics*; D001938:Brazil; D004269:DNA, Bacterial / Q000032:analysis; D005260:Female; D005767:Gastrointestinal Diseases / Q000382:microbiology / Q000503:physiopathology*; D005838:Genotype; D016481:Helicobacter Infections / Q000382:microbiology / Q000503:physiopathology*; D016480:Helicobacter pylori / Q000235:genetics / Q000472:pathogenicity*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D014774:Virulence
D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D004269:DNA, Bacterial; C074689:VacA protein, Helicobacter pylori; C080866:cagA protein, Helicobacter pylori; C063113:ice nucleation protein