Heterogeneity in the Helicobacter pylori vacA and cagA genes : association with gastroduodenal disease in South Africa ?
Background-Helicobacter pylori infection is universally associated with gastritis, but only sometimes with clinically significant disease.
Candidate virulence markers seem to be useful in identifying the pathogenic infections in some populations.
Aims-To investigate the association between putative virulence markers and disease in an African population.
Methods-Fifty nine H pylori strains isolated from dyspeptic patients (11 with peptic ulceration, eight with gastric adenocarcinoma, and 28 with no pathology other than gastritis) were studied for differences in the genes vacA and cagA.
Forty seven (80%) of 59 strains had the vacA signal sequence genotype sl (one sla, 46 slb) and 12 (20%) had subtype s2. vacA mid-region analysis revealed that 40 (68%) strains were vacA ml and 19 (32%) were m2.
All 14 strains from patients with peptic ulceration were vacA sl, in contrast to 23 (66%) of 35 strains from patients with gastritis alone (p<0.01). vacA s2 was found exclusively in patients with gastritis alone (p<0.01).
All strains isolated from patients with gastric adenocarcinoma were s1b/m1 (p<0.005 versus gastritis alone). cagA was detectable in 56 (95%) of 59 isolates.
Strains from patients with peptic ulceration (12113 versus 19/30 with gastritis alone, p=0.05) had the shortest fragment length in the 3'region of cagA, while 4110 strains from patients with gastric cancer had the longest fragment length in this region (p<0.02 versus gastritis alone). (...)
Mots-clés Pascal : Gastrite, Bactériose, Infection, Helicobacter pylori, Spirillaceae, Spirillales, Bactérie, Variation, Génotype, Extrémité 3' OH, Carcinome, Estomac, Facteur risque, Epidémiologie, Homme, République Sud Africaine, Afrique, Appareil digestif pathologie, Estomac pathologie, Génétique, Tumeur maligne, Antigène cagA, Gène vacA
Mots-clés Pascal anglais : Gastritis, Bacteriosis, Infection, Helicobacter pylori, Spirillaceae, Spirillales, Bacteria, Variations, Genotype, 3'-End, Carcinoma, Stomach, Risk factor, Epidemiology, Human, South Africa(Republic), Africa, Digestive diseases, Gastric disease, Genetics, Malignant tumor, Cytotoxin-associated gene, Vacuolating toxin gene
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 99-0491758
Code Inist : 002B05B02F. Création : 22/03/2000.