The causal agent of paratuberculosis Mycobacterium avium subsp. paratuberculosis (MAP) has been detected by various authors, in tissue samples from infected cattle including milk. As demonstrated by a number of published papers, it is obvious that MAP can survive routine pasteurization at 71 to 72°C and can be cultivated from milk and cheese purchased from retail outlets. The aim of our study was to confirm the presence of IS900 as a specific marker of MAP in powdered infant milk by the use of nested PCR. 51 samples of different types of powdered children's food marketed by 10 producers from seven European countries were examined in this study. All samples were cultivated for the presence of viable mycobacteria. IS900 was found in 25 (49.0%) samples originating from seven manufacturers from six different countries. Inhibition was demonstrated in three samples and the other 23 samples were found to be negative. One sample tested positive by use of cultivation, however, the repeated cultivation was negative. The study continues by qPCR for a quantitative determination of MAP in the contaminated samples. In the Czech Republic, similarly as in the other countries, the incidence and prevalence of paratuberculosis in ruminants is increasing. The same applies for the Crohn's disease. The presence of MAP in powdered infant milk should be considered as a risk factor for a consumer when taking into account the autoimmune etiology of Crohn's disease. However, MAP in dairy products may not be the only possible source of allergens provoking the autoimmune process in genetically susceptible people.

Sponsorship

This work was partially supported by the Ministry of Agriculture of the Czech Republic (grant No. 0002716201) and EC: No. QLK2-CT-2000-00928 (SACROHN) and SSPE-CT-2004-501903 (supports the attendance to this Congress).