Studies of the spectrum of H. pylori genetic
variability between childhood and adult isolates may help to elucidate age-specific microbial genetic factors involved in pathogenesis. Rick et al. suggested that in situ Acalabrutinib purchase hybridization techniques, which reflect in vivo gene transcription, may be superior to testing isolates for cagA in vitro and used this method to confirm the association between gastric mucosal H. pylori cagA expression and pediatric gastro-duodenal ulcer disease . While children had a higher prevalence of cagA+ strains compared to adults in one study from China, cagA was not shown to influence their disease phenotype . H. pylori strains from symptomatic children in the USA and Greece were more likely to be cagA- and lack a functional cagPAI, although the USA isolates were more likely to retain outer membrane protein (OMP) and adherence gene expression than adult strains, a possible microbial advantage for early life infection and colonization [4,5]. The adherence properties and expression profile of OMP genes of H. pylori isolates from 200 symptomatic patients were characterized by Odenbreit et al.  Apart from AlpA and AlpB, the expression of other OMPs was variable. In vitro IL-8 expression was again shown to be increased by cagA+ strains, while co-expression of OipA, but not OipA alone,
further enhanced IL-8 secretion. The presence of the putative virulence factor gene iceA,
while common, was not predictive of the extent of inflammation DNA Damage inhibitor on histology in Slovenian children; cagA and vacA s1 genotypes were associated with more severe gastritis and greater bacterial density . Autophagy, an evolutionary conserved process in eukaryotic cells, is an integral component of our innate immune system and is implicated in the pathogenesis of a number of gastrointestinal diseases . H. pylori VacA toxin has recently been shown to induce autophagy in gastric cells in vitro, a potential host defence strategy to limit toxin damage, but autophagosome formation may also facilitate bacterial replication and survival . H. pylori has also been shown to multiply in autophagosomes in macrophages, suggesting that it may be subverting autophagy for its own benefit . The estimated 7.1% prevalence 上海皓元医药股份有限公司 of H. pylori infection in asymptomatic children in the Czech Republic is among the lowest reported in Europe . Sykora et al. found a positive association with increasing age, the number of children in the household (OR 4.26,CI 1.91–9.80), lack of formal education of the father (OR 0.23; CI 0.18–0.64), and institutionalization (OR 6.33; CI 2.25–26.50). Their findings are consistent with improving trends in living and housing conditions in recent years and with decreasing family size. While the prevalence in Western countries and America is decreasing, the high prevalence in Asia remains. Malekzadeh et al.