Prevalence and Clinical Relevance of cagA, vacA,and iceAGenotypes of Helicobacter pyloriIsolated From Slovenian Children

Although infection with Helicobacter pyloriin children mostly induces asymptomatic chronic gastritis, the clinical outcome of H pyloriinfection is generally unpredictable. To identify the risk subgroup of infected children who can progress toward serious gastrointestinal disease, we assessed the prevalence of H pylorivirulence genes cagA, vacA, and iceAin children from southeastern Europe and correlated their presence with the severity of histological changes in the stomach. A total of 165 children (age range 4–18 years, mean 13 years) with H pyloriinfection were studied for a 6-year period. Virulence genes were determined by polymerase chain reaction from biopsy samples. The cagAgene was present in 61.2% of patients. The predominant vacAgenotype was s1m1(42%), followed by s1m2(28%), and s2m2(24%). IceAgenotypes iceA1and iceA2were detected in 62% and 31% of the samples, respectively. Multiple genotypes were found in 11.5% of isolates. The H pyloridensity score, the degree of chronic and acute inflammation, correlated with a cagA-positive status (P< 0.01, P< 0.01, P= 0.01, respectively). Higher bacterial infiltration (P< 0.01) and degree of chronic inflammation (P= 0.03) were detected in vacA s1–positive samples. CagA, vacA s1m1, and iceA1genotypes are the predominant genotypes of H pyloriisolated from the southeastern European pediatric population. CagAand vacA s1are important virulence determinants of H pyloriin children, but were not found associated with an increased incidence of precancerous gastric lesions.