Systemic Amyloid A Amyloidosis in Stejneger’s Beaked Whales (Mesoplodon stejnegeri)

Abstract

Stejneger’s beaked whales ( Mesoplodon stejnegeri) are one of the lesser known species of mammals, with little information available on their population status or incidence of diseases. Recent pathologic investigations on stranded and bycaught wild cetaceans around Hokkaido, Japan, revealed an unusually high incidence of systemic amyloidosis in this species, warranting further investigation. The objective of this study was to further characterize the systemic amyloidosis of Stejneger’s beaked whales by retrospective histopathologic analyses of tissues from animals that stranded in Japan between 1994 and 2018. Various tissues from 35 individuals were examined histologically with hematoxylin and eosin, Congo red, and immunohistochemistry for amyloid A (AA), in which 12 (34%) were diagnosed with systemic amyloidosis. The organs with the highest severity of amyloid deposition were the stomach and intestine. The type of amyloid was confirmed as AA of approximately 9 kDa by 2-dimensional gel electrophoresis with extracted amyloid from the liver and subsequent Western blotting with an antiserum against AA peptide. There were no statistically significant associations between amyloidosis and sex, body condition of the whales, or the presence of chronic inflammation. The high prevalence of this disease might be of concern for overall population numbers, and continued pathologic monitoring of stranded animals is necessary throughout its distributional range.

Amiloidosis sistémica AA: un problema potencial de salud pública

“…Existen estudios observacionales en animales silvestres en cautiverio, que han reportado una alta prevalencia de amiloidosis: mono Rhesus (Macaca mulatta) (Blanchard et al, 1986;Rice et al, 2013, Leung et al, 2019, guepardos (Acinonyx jubatus) (Papendick et al, 1997;Zhang et al, 2008;Franklin et al, 2016), monos tití ( Callithrix jacchus), macacos cola de cerdo (Macaca nemestrina) (Rice et al, 2013;Hukkanen et al, 2006), halcones de caza (Hampel et al, 2009), berrendos (Antilocapra americana) (Martínez et al, 2019), tejones (Meles meles) (Bianco et al, 2020 ), caracales (Caracal caracal) (Greunz et al, 2020); gorriones capuchinos del Japón (Lonchura striata var. domestica) (Nakano & Madarame, 2020) y tupayas (Tupaia belangeri) (Klein et al, 2021) Lo mismo ha sido observado en vida silvestre en especies como: zorros isleños (Urocyon littoralis) (Gaffney et al, 2016), zorros rojos (Vulpes vulpes) (Rising et al, 2017), gaviotas (Larus argentatus) (Jansson et al, 2018)y ballenas de pico de Stejneger (Mesoplodon stejnegeri) (Nakagun et al, 2019;Nakagun et al, 2020), entre otros.…”