milk of livestock as a possible transmission route of helicobacter pylori infection

aim : the current investigation aimed to evaluate ruminant raw milk as a reservoir source of this bacterium and analyze the diversity of caga and vaca genotypes as h. pylori virulence factors to find any relationship between these genotypes in human and animal h. pylori strains. background: the way of transmission of helicobacter pylori as one of the most controversial bacteria in the world which colonizes the human gastric tissue and is responsible for several gastric diseases is still unknown. the possibility of zoonotic transmission of h. pylori is feasible, but is not proven in ruminant reservoirs. materials and methods: overall 210 cow, sheep, goat, camel and buffalo raw milk samples and 100 human gastric biopsy played role in this survey. we applied pcr assays to identify h. pylori, vaca and caga genes. statistical tests were applied for data analysis. results: totally 12(16%) cow, 8(13.79%) sheep, 2 (4.76%) goat, 2(13.33%), buffalo 4(20%) and 82 (82%) of human specimens were confirmed to be h. pylori positive. among which s1a/m2 genotype was more frequent in isolated h. pylori strains and was statistically meaningful between strains. based on statistical analyses the s1b allele of sheep had meaningful relationship with human strains. conclusions: the current survey was prompted by our previous report, according to both results we can conclude that may be sheep act as a reservoir for h. pylori and transmit this bacterium to human via its milk. extended assessments in other geographical regions and other animals is recommended.