Aspergillosis in migrating wild Magellanic penguins (Spheniscus magellanicus)
Aricia BenvenutoEl Gaff
Ana Carolina Ewbank, Aricia Duarte-Benvenuto, Roberta Zamana Ramblas, Pedro Enrique Navas, Marco Gattamorta, Priscilla Carla S. Costa, Carlos Sacristán, José Luiz Catão-Dias
Magellanic penguins (Spheniscus magellanicus) migrate to the continental shelf of southern-southeastern Brazil during winter. Stranded penguins are directed to rehabilitation centers, where they occasionally develop fungal diseases. Aspergillosis, a mycosis caused by ubiquitous opportunistic saprophytic Aspergillus sp., is one of the most important diseases of captive penguins. Nevertheless, its occurrence in the wild is poorly understood. We evaluated two migratory free-ranging Magellanic penguins found stranded dead in Cananéia, São Paulo, Brazil. Upon necropsy, both animals presented fungi-compatible lesions. Histopathology employing Hematoxylin-eosin, periodic acid-Schiff (PAS), and Grocotts methenamine silver stains were performed. A panfungal PCR was performed in air sac and/or lungs samples of two penguins. Body condition varied from thin to cachectic, and both carcasses showed signs of fishing interaction (e.g., cutaneous linear laceration and bruises, marked pulmonary congestion and edema of the visceral pleura), Major gross findings firm pale-yellow caseous masses on visceral pleura, heart, and pulmonary parenchyma, pale-yellowish caseous nodules in airsacs and granulomas adjacent to the syringe/cranial cardiac region and esophageal serosa, diphtheric plaques and granulomatous nodules adhered to Major microscopic findings included marked granulomatous pneumonia with multinucleated giant cells and caseous exudate associated with intralesional PAS-and Grocott-positive septated acute-angle branching hyphae, severe pulmonary congestion, and marked granulomatous airsaculitis. Sequences identical to Aspergillus sp. were retrieved by PCR in both cases. This study documents aspergillosis in free-ranging Magellanic penguins, confirming the species susceptibility in the wild, possibly associated with poor body condition, impaired immunity and natural and anthropogenic challenges faced by S. magellanicus during migration. Some of our microscopic findings resembled those observed in drowned penguins (e.g., severe lung congestion and edema), considered the putative cause of death.