title: Association between cagA, vacAi, and dupA genes of Helicobacter pylori and gastroduodenal pathologies in Chilean patients.
abstract: In addition to the already known cagA gene, novel genetic markers have been associated with Helicobacter pylori (H. pylori) virulence: the dupA and vacAi genes. These genes might play an important role as specific markers to determine the clinical outcome of the disease, especially the vacAi gene, which has been expected to be a good marker of severe pathologies like gastric adenocarcinoma. In the present study, the association of cagA, dupA, and vacAi genes with gastroduodenal pathologies in Chilean patients was studied. One hundred and thirty-two patients positive for H. pylori were divided into two groups-non-severe and severe gastric pathologies-and investigated for the presence of cagA, dupA, and vacAi H. pylori virulence genes by PCR. The cagA gene was detected in 20/132 patients (15.2%), the vacAi1 gene was detected in 54/132 patients (40.9%), the vacAi2 gene was detected in 26/132 patients (19.7%), and the dupA gene was detected in 50/132 (37.9%) patients. Logistic regression model analysis showed that the vacAi1 isoform gene in the infected strains and the severity of the diseases outcome were highly associated, causing severe gastric damage that may lead to gastric cancer (p < 0.0001; OR = 8.75; 95% CI 3.54-21.64). Conversely, cagA (p = 0.3507; OR = 1.62; 95% CI 0.59-4.45) and vacAi2 (p = 0.0114; OR = 3.09; 95% CI 1.26-7.60) genes were not associated with damage, while the dupA gene was associated significantly with non-severe clinical outcome (p = 0.0032; OR = 0.25; 95% CI 0.09-0.65). In addition, dupA gene exerts protection against severe gastric pathologies induced by vacAi1 by delaying the outcome of the disease by approximately 20 years.
authors.affiliation: Laboratory of Bacterial Pathogenesis, Faculty of Biologics Sciences, University of Concepcion, P.O. Box 160-C, Concepcion, Chile.
authors.forename: Esteban
authors.initials: E
authors.lastname: Paredes-Osses
authors.affiliation: Department of Statistics, Faculty of Physics and Math's Sciences, University of Concepcion, Concepcion, Chile.
authors.forename: Katia
authors.initials: K
authors.lastname: Sáez
authors.affiliation: Laboratory of Bacterial Pathogenesis, Faculty of Biologics Sciences, University of Concepcion, P.O. Box 160-C, Concepcion, Chile.
authors.forename: Enrique
authors.initials: E
authors.lastname: Sanhueza
authors.affiliation: Department of Microbiology, Faculty of Biologics Sciences, University of Concepcion, Concepcion, Chile.
authors.forename: Sonja
authors.initials: S
authors.lastname: Hebel
authors.affiliation: Department of Microbiology, Faculty of Biologics Sciences, University of Concepcion, Concepcion, Chile.
authors.forename: Carlos
authors.initials: C
authors.lastname: González
authors.affiliation: Department of Gastroenterology, Faculty of Medicine, University of Concepcion, Concepcion, Chile.
authors.forename: Carlos
authors.initials: C
authors.lastname: Briceño
authors.affiliation: Laboratory of Bacterial Pathogenesis, Faculty of Biologics Sciences, University of Concepcion, P.O. Box 160-C, Concepcion, Chile. apgarcia@udec.cl.
authors.forename: Apolinaria
authors.initials: A
authors.lastname: García Cancino
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000942:Antigens, Bacterial / Q000032:analysis* / Q000235:genetics; D001426:Bacterial Proteins / Q000032:analysis* / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D002677:Chile; D005260:Female; D016481:Helicobacter Infections / Q000235:genetics / Q000382:microbiology* / Q000473:pathology*; D016480:Helicobacter pylori / Q000235:genetics / Q000472:pathogenicity*; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D013270:Stomach / Q000473:pathology; D014774:Virulence; D037521:Virulence Factors / Q000032:analysis* / Q000235:genetics; D055815:Young Adult
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C528428:DupA protein, Helicobacter pylori; C074689:VacA protein, Helicobacter pylori; D037521:Virulence Factors; C080866:cagA protein, Helicobacter pylori