Association of iceA and babA genotypes in Helicobacter pylori strains with patient and strain characteristics

Data on the geographic prevalence of Helicobacter pylori iceA and babA alleles in Eastern Europe are still relatively scant. The aim of this study was to evaluate the prevalence of iceA and babA genotypes in Bulgarian symptomatic patients. The iceA and babA genotypes were evaluated by PCR with pure cultures in strains from 196 and 181 patients, respectively. Mixed infections were found in 10.2% of all 196 patients. Prevalence of H. pylori genotypes in patients with single-strain infections was 69.3% for iceA1, 30.7% for iceA2, 82.4% for cagA ⁺, 89.2% for vacA s1, 10.8% for vacA s2, 39.8% for vacA m1, 60.2% for vacA m2 and 48.8% for babA2. Within the iceA1 positive strains, 94.3% and 88.5% were also vacA s1a and cagA positive, respectively. Of the babA2 positive strains, 100.0%, 92.4% and 72.2% were also vacA s1a, cagA and iceA1 positive, respectively. Ulcer patients had more often strains with cagA positive status and vacA s1a allele. Although neither iceA1 nor babA2 were more common in ulcer patients, the combination of both alleles was more frequent (48.1%) in the ulcer patients than in the rest (28.7%). Clarithromycin susceptible strains had more often iceA1 allele (74.4%) than the resistant strains (55.3%). In conclusion, the results demonstrated a high prevalence of virulent H. pylori in Bulgaria. Both iceA1 and babA2 genotypes were associated with other virulence factors of H. pylori and, in addition, the iceA1 allele was associated with the strain susceptibility.