Incidences of Helicobacter infection in pigs and tracing occupational hazard in pig farmers

Abstract

Helicobacter species (H. sp.) is a gram-negative spiral-shaped motile bacteria that causes gastritis in pigs and also colonizes the human stomach. The current study seeks to assess the prevalence of various H. sp. in the gastric mucosa of slaughtered and dead pigs, as well as the prevalence of Helicobacter infection among pig farmers. A total of 403 stomach samples from various pig slaughter points, 74 necropsy samples from various pig farms and 97 stool samples from pig farmers were collected from Assam, India. Among 477 pig stomach samples tested, 214 samples with gastritis (20.09%) showed Gram negative, spiral-shaped organisms in brush cytology from the mucosal surface, and the rest of the 263 stomach samples without any gastric lesion showed only 3.04% Gram negative, spiral-shaped organisms. In ultrastructure investigation, Scanning Electron Microscopy (SEM) of the four urease positive stomach samples revealed a tightly coiled Helicobacter bacterium (spiral-shaped) found in the mucous lining of the stomach. In histopathological examination of pars esophagia, cardiac and fundic mucosa showed chronic gastritis associated with hemorrhagic necrosis, leucocytic infiltration with neutrophils and macrophages, and lymphoid aggregates (lymphoid follicles) etc. PCR confirmed 16S rRNA genes of Helicobacter suis (H. suis) where a total of 42 (19.63%) out of 214 pig stomach samples and 2 (2.08%) out of 96 stool samples of pig farmers were found positive for H. suis. of these 96 stool samples of pig farmers 3 (3.12%) were confirmed positive for Helicobacter pylori (H. pylori) Phosphoglucosamine mutase gene in PCR. Phylogenic analysis of the 16S rRNA gene of H. suis showed distinct clusters with other H. sp. In conclusion, this study provides evidence for the prevalence of Helicobacter both in pig gastric mucosa and human stool. The findings highlight the need for improved sanitation and hygiene practices among pig farmers to minimize the risk of Helicobacter infection in humans.