Mycobacterium avium subsp. hominissuis INMV 51 infection in a Red-crested turaco (Tauraco erythrolophus)

Abstract

A four years old Red-crested turaco (Tauraco erythrolophus) was found apathetic sitting on the ground of the aviary and died during the clinical examination. Necropsy of the emaciated bird revealed multiple granulomas within the body cavity and inner organs. Histopathological examinations of these granulomas showed epitheloid macrophages and central necrosis demarcated by giant cells. Using Ziehl-Neelsen staining, massive accumulations of acid-fast bacteria were found within the lesions and the preliminary diagnosis “avian tuberculosis” was made. This infectious disease is mainly caused by Mycobacterium avium subsp. avium (Maa) or M. genavense (Mg). However, microbiological culture followed by PCR revealed the occurrence of Mycobacterium avium subsp. hominissuis (Mah). The isolate was assigned to INMV profile 51, which has been described in Asia and Europe mainly in humans, as well as in pigs and cattle until now. When infected birds have intensive contact with humans, a risk assessment must be carried out based on the identity of the causative pathogen. For this purpose, the determination of the species and if applicable the subspecies is mandatory and an additional molecular typing, e.g. by INMV profiling, helpful.