Prevalence and Clinical Relevance of <i>cagA, vacA,</i> and <i>iceA</i> Genotypes of <i>Helicobacter pylori</i> Isolated From Slovenian Children

Abstract

ABSTRACT Background: Although infection with Helicobacter pylori in children mostly induces asymptomatic chronic gastritis, the clinical outcome of H pylori infection is generally unpredictable. To identify the risk subgroup of infected children who can progress toward serious gastrointestinal disease, we assessed the prevalence of H pylori virulence genes cagA, vacA , and iceA in children from southeastern Europe and correlated their presence with the severity of histological changes in the stomach. Materials and Methods: A total of 165 children (age range 4–18 years, mean 13 years) with H pylori infection were studied for a 6‐year period. Virulence genes were determined by polymerase chain reaction from biopsy samples. Results: The cagA gene was present in 61.2% of patients. The predominant vacA genotype was s1m1 (42%), followed by s1m2 (28%), and s2m2 (24%). IceA genotypes iceA1 and iceA2 were detected in 62% and 31% of the samples, respectively. Multiple genotypes were found in 11.5% of isolates. The H pylori density score, the degree of chronic and acute inflammation, correlated with a cagA ‐positive status ( P &lt; 0.01, P &lt; 0.01, P = 0.01, respectively). Higher bacterial infiltration ( P &lt; 0.01) and degree of chronic inflammation ( P = 0.03) were detected in vacA s1 –positive samples. Conclusion: CagA, vacA s1m1 , and iceA1 genotypes are the predominant genotypes of H pylori isolated from the southeastern European pediatric population. CagA and vacA s1 are important virulence determinants of H pylori in children, but were not found associated with an increased incidence of precancerous gastric lesions.