Helicobacter pylori vacA Mosaicism and New Primers for vacA Signal Sequence Indigenous to Korea / 대한소아소화기영양학회지

PURPOSE: Helicobacter pylori has been known to have diverse vacA allelic types. The purpose of the study was to identify vacA diversity in Korea and design new primers for signal sequence alleles indigenous to Korea. METHODS: Fifty antral biopsy specimens, which had been proven to be H. pylori-positive, were examined for vacA status; signal sequence and mid-region. After PCR amplification and DNA sequencing, vacA alleles of Korean H. pylori strains were compared with those from other countries. RESULTS: Among Korean H. pylori strains vacA alleles with all combinations of signal sequence and mid-region were found, with the exception of s1b or s2. vacA genotype s1c/m1 was predominant in Korea. We found that GGGAGCGTTR in s1a and GGGGYTATTG in s1c were the indigenous sequences to Korea and constructed the new Korean specific primers for the vacA signal sequence; VASK-F, VASK-R, S1AK-F, and S1CK-F. CONCLUSION: This study showed that s1c/m1 is the predominant type of vacA allele in Korea. We designed new primers for the vacA signal sequence.

High Seroprevalence of Helicobacter pylori Infection in Korean Adolescent Athletes / 대한소아소화기영양학회지

PURPOSE: Poor living conditions such as overcrowding and sharing a bed are reported to be significant risk factors for H. pylori infection throughout childhood. We investigated the prevalence of Helicobacter pylori infection in Korean athletes who are obliged to live together in training camps over six months a year. METHODS: Blood sampling and surveying through questionnaire were performed on 440 regular high school students (228 boys and 212 girls) and 220 athletes (148 boys and 72 girls) of a physical education high school. We measured serum IgG Ab to H. pylori in order to compare the prevalence of H. pylori infection between normal adolescents and athletes. In addition, we conducted a nutritional analysis and questionnaire survey for socioeconomic status in order to compare other risk factors that might influence H. pylori infection between groups. RESULTS: The prevalence (43.2%) of H. pylori infection in athletes was higher than that (22.7%) in the controls. No significant differences in the nutritional factors or socioeconomic status, such as Hollingshead index, type of house, and crowding index, were found between the groups. Multivariate analysis showed that crowding and the difference in school type were the significant predictors of H. pylori seropositivity after controlling for dietary and socioeconomic factors. CONCLUSION: Living together in training camps might be a significant risk factor for H. pylori infection in athletes.