title: Infection with cagA-positive and cagA-negative types of Helicobacter pylori among children and adolescents with gastrointestinal symptoms in Latvia.
abstract: In order to determine the prevalence of concomitant cagA-positive and cagA-negative Helicobacter pylori genotypes in individual subjects, a group of 56 symptomatic patients (aged 8-18 years) was studied. Among 31 patients culture-positive for Helicobacter pylori, only cagA-positive colonies were isolated from 18 patients, both cagA-positive and cagA-negative genotypes were isolated from 4 patients, and in 9 patients all of the individual colonies isolated were cagA-negative, but in seven of them a pool of colonies was positive for cagA. Thus, the presence of both cagA-positive and cagA-negative genotypes in the same individual was identified in 11 of the 31 culture-positive patients tested, and most of the patients predominantly colonized by cagA-negative strains also harbored a small amount of cagA-positive strains. Previous or current infection with cagA-positive strains of Helicobacter pylori was observed in 50 of the 56 patients studied.
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D000942:Antigens, Bacterial / Q000032:analysis / Q000378:metabolism*; D001426:Bacterial Proteins / Q000032:analysis / Q000378:metabolism*; D016009:Chi-Square Distribution; D002648:Child; D015331:Cohort Studies; D004269:DNA, Bacterial / Q000032:analysis; D005260:Female; D005767:Gastrointestinal Diseases / Q000453:epidemiology* / Q000382:microbiology; D005838:Genotype; D016481:Helicobacter Infections / Q000175:diagnosis / Q000453:epidemiology*; D016480:Helicobacter pylori / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D007844:Latvia / Q000453:epidemiology; D008297:Male; D016133:Polymerase Chain Reaction / Q000379:methods; D015995:Prevalence; D011336:Probability; D011446:Prospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D017678:Sex Distribution
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D004269:DNA, Bacterial; C080866:cagA protein, Helicobacter pylori