Pathophysiology
MAP causes Johne's disease in cattle and other ruminants, and it has long been suspected as a causative agent in Crohn's disease in humans; this connection is controversial.
Recent studies have shown that MAP present in milk can survive pasteurization, which has raised human health concerns due to the widespread nature of MAP in modern dairy herds. MAP survival during pasteurization is dependent on the D72C-value of the strains present and their concentration in milk. It is heat resistant and is capable of sequestering itself inside white blood cells, which may contribute to its persistence in milk. It has also been reported to survive chlorination in municipal water supplies.
MAP is a slow growing organism and is difficult to culture. Bacterial cultures were regarded as Gold standards for detection of MAP. Detection is very limited in fresh tissues, food, and water.
It is not susceptible to antituberculosis drugs (which can generally kill Mycobacterium tuberculosis), but can only be treated with a combination of antibiotics such as rifabutin and a macrolide such as clarithromycin. Treatment regimens can last years.
Read more about this topic: Mycobacterium Avium Subspecies paratuberculosis