Genotypic, clinical, and demographic characteristics of children infected with Helicobacter pylori

Helicobacter pylori isolates vary between geographic regions. Certain H. py lori genotypes may be associated with disease outcome. Thirty-eight childre n underwent diagnostic upper endoscopy at four medical centers and were ret rospectively analyzed to determine if Ii. pylori virulence genes were assoc iated with endoscopic disease severity, histologic parameters, and host dem ographics. The ii. pylori virulence genotype was analyzed by a reverse hybr idization line probe assay and type-specific PCR. Endoscopic ulcers or eros ions were found in 17 (45%) patients, with 13 (34%) of these patients havin g antral nodularity. Histological gastritis, of varying severity, was prese nt in all children. Four patients harbored more than one Ii. pylori strain: one subject had both cagA(+) and cagA-negative strains, while three patien ts harbored either two different cagA-negative strains (two children) or tw o cagA(+) strains tone child). There were 28 (74%) cagA(+) isolates; 19 wer e associated with the vacA s1b genotype, 7 were associated with the vacA sl a genotype. 1 was associated with the vacA s1c genotype, and 1 was associat ed with the s2 genotype. Of 14 cagA-negative isolates, 6 were vacA s2 genot ype, 4 were vacA s1b, 3 were vacA sla, and I was, vacA sie. Nine of ten (90 %) Hispanics had similar II. pylori strains (vacA s1b,ml), and all Asian-Ca nadian children were infected by strains with vacA sie genotype, No correla tion between Ii. pylori strain and endoscopic or histopathologic abnormalit ies was found. This study provides a baseline framework of North American c hildren and their H. pylori strains, serving as a powerful epidemiological tool for prospective investigations to better understand the transmission a nd evolution of diverse disease outcomes.