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Helicobacter pylori vacA and cagA gen: changes over a period of 15 years in Spain

Abstract number: P1961

Agudo S., Alarcón T., Urruzuno P., Pérez-Pérez G., López-Brea M.

Introduction: The presence of cytotoxin-associated gene A (cagA) and expression of vacuolating cytotoxin activity encoded by vacuolating cytotoxin gene A (vacA) are considered the two major virulent markers of H. pylori. VacA and CagA of H. pylori strains showed genetic variability. The aim of this study was to determine the prevalence of CagA and VacA genotypes among H. pylori isolated in Madrid, Spain over two periods: 1994 and 2008.

Methods: We obtained 64 biopsies from symptomatic gastric patients from four different regions (Madrid, Aviles, Almeria and Ibiza) of Spain in 1995 and 90 biopsies from patients with gastric symptoms from Madrid, Spain in 2008. Standard microbiological procedures were used for H. pylori culture. DNA extraction was carried out with phenol/chloroform/isoamil alcohol (25:24:1) in 1994 and by the NucliSens easyMAG platform with the NucliSens magnetic extraction reagents (bioMérieux) in 2008. VacA genotypes (s, m) were determined by PCR and agarose gel. CagA status was determined by PCR and those CagA negative, we confirmed the absence of the pathogenicity island by "empty-site" PCR. The identification of the number and type of CagA EPIYA motifs was based on sequencing analyses.

Results: The results of VacA are showed in the table 1. Around 27% biopsies were cagA gene positive in strains from Madrid 1994 and 2008. 69% were cagA gene positive in strains from the rest of regions in 1994. We confirmed the lack of pathogenicity island in the rest of strains that were CagA negative. CagA with three EPIYA motifs (ABC) was observed in 53% and 68% of CagA positive strains in Madrid 1994 and 2008, respectively.

Conclusions: In Madrid, Spain most of H. pylori isolates are VacA s2/m2 and CagA negative in both periods of time, different to the rest of the regions in 1994. The prevalence of CagA proteins with three EPIYA motifs (ABC) was the most frequently found.

 ns1m1/m2s2m2s2m1
  n%n%n%
Madrid22522.71672.714.5
Almeria201470.052514.5
Aviles6233.3350116.7
Ibiza1161062.5212.5212.5
Madrid 20082902325.66471.122.2
12 strains showed mixed signals; 21 strain showed mixed signals.

Session Details

Date: 10/04/2010
Time: 00:00-00:00
Session name: Abstracts 20th European Congress of Clinical Microbiology and Infectious Diseases
Subject:
Location: Vienna, Austria, 10 - 13 April 2010
Presentation type:
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