Mycobacterium shimoidei causing granulomatous inflammation in a captive bird species, the white-cheeked turaco

Mycobacteriosis in avian species is generally caused by Mycobacterium avium subsp. avium and M. genavense, although sporadic reports also exist of other nontuberculous mycobacterium species in birds. Here, we describe disseminated mycobacteriosis caused by M. shimoidei (a rare and infrequently reported pathogen in humans and animals) in a bird species. A captive, adult white-cheeked turaco (Tauraco leucotis) was presented because of persistent dyspnea unresponsive to treatment. The animal was treated unsuccessfully with antimicrobials and later euthanized on welfare grounds. At autopsy, granulomas were identified in the lungs and spleen. Histologically, the coalescing granulomas with central necrosis contained numerous chains of slender, slightly curved, 2-µm acid-fast bacilli, suggesting mycobacterial infection. Bacterial isolation confirmed Mycobacterium spp., which was identified as M. shimoidei by partial sequencing of the 16S rRNA and rpoB genes. Our report expands the known host range of M. shimoidei and highlights the importance of molecular testing methods in identifying atypical nontuberculous mycobacteria (NTM) in zoologic collections. Our case also underscores the need for enhanced epidemiologic surveillance of NTM infections in avian species, given their potential implications for both animal and public health.