Frequency of vacA, cagA and babA2 virulence markers in Helicobacter pylori strains isolated from Mexican patients with chronic gastritis
Abstract number: P805
Paniagua G.L., Monroy E., Rodriguez R., Rodriguez C., Arroniz S., Cortés J.L., Camacho A., Negrete E., Vaca Pacheco S.
Objective:Helicobacter pylori has been strongly associated with chronic gastritis, peptic and duodenal ulcers, and is a risk factor for gastric cancer. Three major virulence factors of H. pylori have been described: the vacuolating toxin (VacA), the cytotoxin-associated gene product (CagA) and the adhesion protein BabA2. Since considerable geographic diversity in the prevalence of H. pylori virulence factors has been reported, the aim of this work was to establish the H. pylori and vacA, cagA and babA2 gene status in one hundred adult patients, from a marginal urban area of Mexico, with chronic gastritis.
Methods:H. pylori was identified in cultures of gastric biopsies by nested PCR. vacA and cagA genes were detected by multiplex PCR, whereas babA2 gene was identified by conventional PCR.
Results:H. pylori-positive biopsies were 81%. All H. pylori strains were vacA+; 38.3% were cagA+; 21% were cagA+ babA2+ and 6.2% were babA2+. Mexican strains examined possessed the vacA s1, m1 (40.7%), s1, m2 (28.4%), s2, m1 (16%) and s2, m2 (14.8%) genotypes.
Conclusion: These results show that the Mexican patients suffering chronic gastritis we have studied had a high incidence of infection by H. pylori. Most H. pylori strains examined may be considered as highly virulent since sixty six percent of them possessed two or three of the virulence markers analyzed, with s1, m1 as the most frequent alleles of vacA.
Acknowledgements: Project supported by PAPIIT IN216508, DGAPA, UNAM.
|Session name:||19th European Congress of Clinical Microbiology and Infectious Diseases|
|Location:||Helsinki, Finland, 16 - 19 May 2009|
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