Morell Maria, IJsseldijk Lonneke L, Berends Alinda J, Gröne Andrea, Siebert Ursula, Raverty Stephen A, Shadwick Robert E, Kik Marja J L
Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, 25761 Büsum, Germany.
Zoology Department, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
Animals (Basel). 2021 Oct 26;11(11):3058. doi: 10.3390/ani11113058.
Evidence of hearing impairment was identified in a harbour porpoise () on the basis of scanning electron microscopy. In addition, based on histopathology and immunohistochemistry, there were signs of unrelated cerebral toxoplasmosis. The six-year old individual live stranded on the Dutch coast at Domburg in 2016 and died a few hours later. The most significant gross lesion was multifocal necrosis and haemorrhage of the cerebrum. Histopathology of the brain revealed extensive necrosis and haemorrhage in the cerebrum with multifocal accumulations of degenerated neutrophils, lymphocytes and macrophages, and perivascular lymphocytic cuffing. The diagnosis of cerebral toxoplasmosis was confirmed by positive staining of protozoa with anti- antibodies. Tachyzoites were not observed histologically in any of the examined tissues. Ultrastructural evaluation of the inner ear revealed evidence of scattered loss of outer hair cells in a 290 µm long segment of the apical turn of the cochlea, and in a focal region of ~ 1.5 mm from the apex of the cochlea, which was compatible with noise-induced hearing loss. This is the first case of concurrent presumptive noise-induced hearing loss and toxoplasmosis in a free-ranging harbour porpoise from the North Sea.
基于扫描电子显微镜检查，在一只港湾鼠海豚（）身上发现了听力受损的证据。此外，根据组织病理学和免疫组织化学检查，发现了与脑弓形虫病无关的迹象。这只6岁的个体于2016年在荷兰海岸的栋堡搁浅，数小时后死亡。最显著的大体病变是大脑多灶性坏死和出血。大脑组织病理学显示，大脑广泛坏死和出血，伴有多灶性变性中性粒细胞、淋巴细胞和巨噬细胞聚集，以及血管周围淋巴细胞套袖样浸润。通过原虫与抗抗体的阳性染色证实了脑弓形虫病的诊断。在所检查的任何组织中均未在组织学上观察到速殖子。内耳的超微结构评估显示，在耳蜗顶转290 µm长的节段以及距耳蜗顶端约1.5 mm的一个局灶区域，有散在的外毛细胞丢失迹象，这与噪声性听力损失相符。这是北海一只野生港湾鼠海豚同时出现推定的噪声性听力损失和弓形虫病的首例病例。
