Case report: granulomatous hepatitis due to Mycobacterium avium in an Atlantic yellow-nosed albatross (Thalassarche chlororhynchos) from Southern Brazilian coast.

This study reports a granulomatous hepatitis caused by Mycobacterium avium in an Atlantic yellow-nosed albatross (Thalassarche chlororhynchos) found dead on Brazil southern coast. At necropsy, the albatross was cachectic and the liver was severely enlarged with multifocal to coalescing white nodules. Histopathological evaluation revealed multifocal to coalescing granulomas with caseous necrosis, surrounded by an infiltrate of macrophages and multinucleated giant cells, and a thin capsule of fibrous connective tissue. The Fite-Faraco staining technique revealed multiple acid-fast bacilli (AFB) stained in magenta, predominantly in the areas of necrosis. Bacterial culture and polymerase chain reaction (PCR) analysis confirmed the presence of Mycobacterium avium in liver samples. This case underscores the importance of wildlife surveillance in coastal regions. Pelagic birds like the Atlantic yellow-nosed albatross can harbor pathogenic agents that represent a threat to wildlife and domestic animals. Enhanced monitoring and research are essential to understand the epidemiology and potential risks associated with such infections in coastal ecosystems.