Genotyping of the Helicobacter pylori isolates of raw milk and traditional dairy products

Abstract

Notwithstanding the substantial clinical impact of Helicobacter pylori, its convinced routes of transmission and sources have not been reported. Based on the quarrelsome hypothesis, foods and especially dairy products play an authoritative role in the transmission of H. pylori to humans. The current investigation was done to study the prevalence rate and distribution of vacA genotypes in the H. pylori strains isolated from the raw milk and traditional dairy products. Three-hundred milk and dairy samples were collected and directly transported to laboratory. Samples were cultured and H. pylori isolates were approved using the 16s rRNAbased PCR amplification. Positive strains were tested for distribution of vacA genotypes using the multiplex-PCR. Sixty out of 300 samples (20%) harbored H. pylori. Prevalence of H. pylori in milk and traditional dairy products were 38.75% and 13.18%, respectively. Ovine milk (45%) and traditional cheese (40%) had the highest prevalence of H. pylori. VacAs1a (91.66%), vacAm1a (61.61%) vacAs2 (36.66%) and vacAm2 (31.66%) were the most commonly detected genotypes. Ovine milk and traditional cheese had the most diverse genotypes. S1am1a (41.66%), s2m1a (25%), s1am2 (16.66%) and s2m2 (13.33%) were the most commonly detected combined genotypes. Raw milk and traditional dairy products are latent sources of H. pylori. Similarity in the genotyping pattern of H. pylori strains of various samples represents their similar sources of infection. Further studies are required to found the exact sources of H. pylori strains in raw milk and traditional dairy products.