Mycobacterium avium subsp. paratuberculosis in a mouflon herd without clinical symptoms monitored using IS900 real-time PCR: a case report

The aim of this study was to monitor over two years a farmed mouflon herd for the presence and persistence of Mycobacterium avium subsp. paratuberculosis (MAP) using an IS900 real-time PCR method. This study followed the previous monitoring of the herd using a cultivation method which showed only a minimal infection load among the animals. Although no mouflon showed clinical symptoms, 35.7% and 80% of ewes were IS900-positive in 2008 and 2009, respectively. In seven out of 21 adult ewes, the presence of the IS900 sequence was determined in 2008 as well as in 2009. Between the first and second sampling, twenty-three mouflon lambs born and kept with the ewes were examined. Almost one third of them (30.4%) were proven to have the MAP sequence in their faeces. Also, 75% environmental samples from the mouflon farm showed positivity. Infected animals without clinical symptoms which low sensitivity cultivation does not detect represent a source of infection for other animals. Therefore, real-time PCR has a crucial role in paratuberculosis control programs, especially in control of the disease by the culling of infected animals.