Detection ofMycobacterium avium subspecies paratuberculosisspecific IS900 insertion sequences in bulk-tank milk samples obtained from different regions throughout Switzerland

SinceMycobacterium aviumsubspeciesparatuberculosis(MAP) was isolated from intestinal tissue of a human patient suffering Crohn's disease, a controversial discussion exists whether MAP have a role in the etiology of Crohn's disease or not. Raw milk may be a potential vehicle for the transmission of MAP to human population. In a previous paper, we have demonstrated that MAP are found in raw milk samples obtained from a defined region in Switzerland. The aim of this work is to collect data about the prevalence of MAP specificIS900insertion sequence in bulk-tank milk samples in different regions of Switzerland. Furthermore, we examined eventual correlation between the presence of MAP and the somatic cell counts, the total colony counts and the presence ofEnterobacteriaceae.