Brief communications and case reports - A case of intestinal Mycobacteriumsimiae infection in an SIV-infected immunosuppressed rhesus monkey

Although Mycobacterium simiae was identified and classified more than three decades ago, only a few cases are mentioned in the current Literature. Aft er experimental simian immunodeficiency virus infection, a 9-year-old femal e rhesus monkey (Macaca mulatta) developed progressive immunosuppression an d gastrointestinal disease very similar to the clinical and pathomorphologi c features of Johne's disease, which is caused by M. paratuberculosis. Acid -fast-positive bacteria reacted immunohistochemically with antibodies again st M. paratuberculosis and M. bovis but were not useful for differentiation because of a high degree of cross-reactivity. Ln contrast to immunohistoch emistry and histopathology, biochemical methods and cycle sequencing analys is of the 16S ribosomal RNA identified M. simiae as the disease-causing pat hogen. This case demonstrates the importance of molecular biological method s for the diagnosis of M. simiae infection in monkeys.