Helicobacter pylori-induced Gastritis in Experimentally Infected Conventional Piglets

Abstract

A conventional nonmutant animal that could be experimentally infected with Helicobacter pylori isolates would be a useful animal model for human H. pylori-associated gastritis. Gnotobiotic and barrier-born pigs are susceptible to H. pylori infection, but attempts to infect conventional pigs with this bacterium have been unsuccessful. In the present study, a litter of eight 20-day-old crossbreed piglets were purchased from a commercial farm. Six of them were orally challenged two to five times at different ages, between 29 and 49 days, with doses of H. pylori inoculum containing approximately 10(9) bacterial cells. Two animals served as controls. The inoculation program began 2 days postweaning when the piglets were 29 days of age. Prior to every inoculation, the piglets were fasted and pretreated with cimetidine, and prior to the first and second inoculation each piglet also was pretreated with dexamethasone. The challenged piglets were euthanasized between 36 and 76 days of age. H. pylori colonized all six inoculated piglets. The pathology of the experimentally induced gastritis was examined macroscopically and by light and electron microscopy. H. pylori induced a severe lymphocytic gastritis in the conventional piglets and reproduced the large majority of the pathologic features of the human disease. Therefore, the conventional piglet represents a promising new model for study of the various pathogenic mechanisms involved in the development of lesions of the human H. pylori-associated gastritis.

Correlation between Different Helicobacter Morphotypes and Histological Changes in Pig Gastric Mucosa

“…Results of this study indicated that that mononuclear cells (lymphocytes and plasma cells) were predominant cell types of inflammatory infiltrate, whereas polymorphonuclear leukocytes (neutrophils) were not present. Previous study also point to lack of neutrophile in inflammatory infiltrate of experimentally induced H. pylori infection in conventional piglets [22]. This is in accordance to results published by other autors [1,3,15,22], but contrary to chronic active gastritis associated with Helicobacter spp.…”

“…Previous study also point to lack of neutrophile in inflammatory infiltrate of experimentally induced H. pylori infection in conventional piglets [22]. This is in accordance to results published by other autors [1,3,15,22], but contrary to chronic active gastritis associated with Helicobacter spp. in humans [9].…”

“…Signs of gastric inflammation, such as lymphocytic and plasmacytic inflammatory cell infiltrates and lymphoid follicle formation, are most prominent in H. pylori-inoculated pigs [14]. A similar conclusion was drawn from results of an experimental infection study in: gnotobiotic pigs [15], miniature pigs [12] and conventional pigs [13,22]. Results for histopathological examination revealed a moderate to severe focal or diffuse lymphoplasmacytic inflammation and lymphoid follicles with germinal centers in all HLO-positive pyloric mucosa, which corresponds to the results of an experimental study [19].…”

“…Gastritis is the result of a natural infection with H. pylori in humans [26] and conventional pigs [13] or an experimental induced infection in gnotobiotic piglets [3,14,15], miniature pigs [12] and conventional piglets [22]. In both, humans and pigs, the presence of H. pylori correlates with an inflammatory response, but there are differences in inflammatory cell population.…”

Effect of <i>Myristica fragrans</i> Houtt. Seed (Nutmeg) on <i>Helicobacter pylori</i> induced gastritis in albino rats: <i>in vitro</i> and <i>in vivo</i> studies

“…The activity of Myristica fragrans in reducing H. pylori load and thus effecting healing of the gastritis compared favourably well with the control drug (Ofloxacin) which would have been expected to have better activity being a pure drug. There are several animal models available to help understand the pathogenesis of H. pylori infection, including gnotobiotic piglets, athymic mice and monkeys (Poutahidis et al, 2001;Raghavan et al, 2003;Kodama et al, 2005 In addition, the in vitro experiment revealed a broad antibacterial spectrum of nutmeg extracts including activity against some restricted organisms such as H. pylori. However, it did not demonstrate any antibacterial activity against Escherichia coli and Klebsiella pneumoniae tested in our preliminary study.…”