The presence of Mycobacterium avium subsp avium in common pheasants (Phasianus colchicus) living in captivity and in other birds, vertebrates, non-vertebrates and the environment

Although avian mycobacteriosis is not prevalent among domestic fowl used for intensive husbandry, it has been described in both free living birds and birds in captivity, e.g., zoological gardens and small fowl flocks. In this study, we examined 305 pheasants from six flocks as well as 70 other birds belonging to 14 species and 97 other vertebrates caught in a closed area. We also investigated the prevalence of mycobacteria in non-vertebrates (earthworms) and soil in two pheasant flocks. Mycobacterium avium subsp. avium (M. a. avium) was isolated in four flocks from 17 (5.6%) pheasants. In one M. a. avium-infected pheasant co-infection with M. a. hominissuis was diagnosed. Granulomatous inflammatory lesions were observed in liver and spleen in only four M. a. avium-infected pheasants originating from two flocks. From the other 38 pheasants other mycobacterial species were isolated, such as M. fortuitum, M. terrae, M. triviale, M. chelonae, M. scrofulaceum, M. smegmatis, M. flavescens, M. diernhoferi and non-identifiable mycobacterial species. In the group of 70 birds of other species, we identified M. a. avium in two (2.9%) goshawks (Accipiter gentilis). We did not isolate M. a. avium from any of the other 97 vertebrates, the 391 environment samples or 97 earthworms.