Plasticity Region Genes jhp0940, jhp0945, jhp0947, and jhp0949 of Helicobacter pylori in Isolates from Mexican Children

Abstract

The genes jhp0940, jhp0945, jhp0947, and jhp0949 belong to the plasticity region of the Helicobacter pylori genome. Due to their prevalence in isolates from patients with gastritis, duodenal ulcer, and gastric cancer, they have been proposed as markers of gastroduodenal diseases. These genes are associated with pro-inflammatory cytokine induction through the NF-κB activation pathway. Nevertheless, the status of these genes is unknown in H. pylori isolates from children. The aim of the present work was to determine the frequency of the jhp0940-jhp0945-jhp0947-jhp0949 genes in H. pylori isolates from children. We identified the jhp0940, jhp0945, jhp0947, and jhp0949 genes and the relationship of each with the virulence factors cagA, cagPAI, and dupA by PCR in 49 isolates of H. pylori from children. The results were corroborated using dot blots. In addition, we compared the prevalence of these genes with the prevalence in adults. The prevalence of jhp0940 (53.1%), jhp0945 (44.9%), jhp0947 (77.6%), and jhp0949 (83.7%) was determined in the isolates from children, as was the prevalence of the virulence genes cagA (63.3%), cagPAI (71.4%), and dupA (37.5%). No association was found between the four genes of the plasticity region and the virulence genes. The presence of the intact locus integrated by jhp0940-jhp0945-jhp0947-jhp0949 was very common among the isolates from children. The genes jhp0940, jhp0947, and jhp0949 were present in more than 50% of the H. pylori isolates, and the joint presence of jhp0940-jhp0945-jhp0947-jhp0949 was very frequent. The frequency of these genes in isolates from children could contribute to the virulence of H. pylori and the evolution of the infection.