Detection of Mycobacterium avium subsp. paratuberculosis (MAP) by real time PCR in dairy herds and evaluation of risk assessment for public health

Mycobacterium avium ssp. paratuberculosis (MAP) is the causative agent of paratuberculosis (called Johne´s Disease), a chronic contagious enteritis of ruminants, especially of dairy cattle. Dairy cattle infected clinically and subclinically with MAP shed the pathogen periodically in their faeces, milk and semen. Since the beginning of the last century, it was controversially discussed whether MAP is concerned in the pathogenesis of humans Crohn?s disease. In spite of direct contact to MAP infected animals, humans may be exposed to MAP by consumption of contaminated milk products. From the public health point of view, an increasing number of studies have been focused on milk and dairy products which are considered to be a major source of exposure for humans. MAP can not be completely inactivated by commercial pasteurization techniques. The incidence of culturable MAP in pasteurized milk worldwide is estimated between about 1?3%. The objective of this study was to detect MAP by Real Time PCR in dairy herds in the region of Keşan in Edirne. 270 fecal samples directly from rectum of asymptomatic cows over then 2 yr old from 30 dairy herds in 15 districs and in addition 30 bulk milk samples and 15 districs tank milk samples were enclosed in the study. All fecal and milk samples were negative for MAP genom by Real Time PCR assay. The results of this study showed that MAP could not be detected in investigated dairy herds or it may be presence in very low number or under detection limit (102 CFU/g faeces and 102 CFU/10 ml milk) in regarding on the sensivity of Real Time PCR assay. To our knowledge, this work is the first small prevalence study of MAP in dairy farms in a region of Turkey. In this study, the absence of MAP in feaces and milk samples has an impact on public health in particularly in the Kesan region, however this study supports a large study in different districs of Turkey for screening dairy herds for prevalence and diagnosis of MAP.