cagA gene and vacA alleles in Spanish Helicobacter pylori clinical isolates from patients of different ages

The prevalence of the cagA gene and vacA alleles in 124 Spanish Helicobacte r pylori clinical isolates from patients of different ages ranging from 3 t o 78 years was studied (21 patients less than or equal to 10 years, 30 pati ents 11-20 years, 17 patients 21-40 years, 31 patients 41-60 years and 25 p atients 61-80 years). The cagA gene and vacA sl or vacA s2 alleles were ide ntified by PCR from the strain. 66.9% of the isolates were cagA(+) and 33.1 % cagA(-). vacA s1 was detected in 48.4% of the isolates and vacA s2 in 51. 6%. 44.4% of patients were cagA(+)/vacA s1, 22.5% were cagA(+)/vacA s2, 4% were cagA(-)/vacA sl and 29% were cagA(-)/vacA s2. The percentage of cagA() isolates and the vacA sl alleles in the different groups were as follows: 23.8% and 28.6% in 0-10 years, 40% and 30% in 11-20 years, 88.2% and 70.6% in 21-40 years, 90.3% and 70.9% in 41-60 years and 92% and 44% in the 61-7 8 years group. 93% (54/58) of isolates found in ulcer patients and 90.9% (1 0/11) of isolates from gastritis patients older than 20 years were cagA(+). In patients younger than 20 years ulcer disease was rare with 60% of isola tes being cagA(+) (315) compared with 31.6% cagA(+) isolates (12/38) in pat ients suffering from gastritis in the younger group. The prevalence of the cagA gene and vacA s1 allele increased with age, being more frequent in old er patients than in younger. (C) 1999 Federation of European Microbiologica l Societies. Published by Elsevier Science B.V. All rights reserved.