Salla Raquel F, Jones-Costa Monica, Abdalla Fabio C, Vidal Felipe A P, Boeing Guilherme A N S, Oliveira Cristiane R, Silva-Zacarin Elaine C M, Franco-Belussi Lilian, Rizzi-Possignolo Gisele M, Lambertini Carolina, Toledo Luís F
Laboratory of Natural History of Brazilian Amphibians, Biology Institute, State University of Campinas, Campinas, São Paulo 13083-862, Brazil.
Dis Aquat Organ. 2020 Dec 17;142:177-187. doi: 10.3354/dao03541.
Amphibians have been facing a pandemic caused by the deadly fungus Batrachochytrium dendrobatidis (Bd). Although studies have elucidated cutaneous and homeostatic disturbances, it is still unknown if the hepatic function can be affected or if hepatic effects differ among host species. Thus, we evaluated the effects of an experimental Bd infection on the liver (histopathology and the hepatosomatic index) of 2 anuran species (Xenopus laevis and Physalaemus albonotatus) with different susceptibilities to Bd infection and compared them to uninfected controls. Bd infection increased the melanomacrophage cell area and induced leukocyte infiltration in both species. The effects were more pronounced in the sensitive species, P. albonotatus, which showed severe reduction in glycogen stores and liver atrophy, due to energetic imbalance. Hepatocytes of P. albonotatus also showed ballooning degeneration (vacuolization), which could lead to cell death and liver failure. Our results provide evidence that although the sensitive species showed more severe effects, the tolerant species also had hepatic responses to the infection. These findings indicate that hepatic function can play an important role in detoxification and in immune responses to chytridiomycosis, and that it may be used as a new biomarker of health status in chytrid infections.
两栖动物正面临由致命真菌蛙壶菌（Batrachochytrium dendrobatidis，简称Bd）引发的疫情。尽管已有研究阐明了皮肤和体内稳态方面的紊乱，但肝功能是否会受到影响，或者宿主物种之间肝脏的影响是否存在差异，仍不明确。因此，我们评估了实验性Bd感染对两种对Bd感染敏感性不同的无尾目物种（非洲爪蟾Xenopus laevis和白背侧蛙Physalaemus albonotatus）肝脏的影响（组织病理学和肝体指数），并将其与未感染的对照组进行比较。Bd感染增加了两种物种的黑素巨噬细胞面积并诱导了白细胞浸润。这些影响在敏感物种白背侧蛙中更为明显，由于能量失衡，该物种的糖原储备严重减少且肝脏萎缩。白背侧蛙的肝细胞还出现了气球样变性（空泡化），这可能导致细胞死亡和肝功能衰竭。我们的结果表明，尽管敏感物种表现出更严重的影响，但耐受物种对感染也有肝脏反应。这些发现表明，肝功能在解毒和对壶菌病的免疫反应中可能发挥重要作用，并且它可能被用作壶菌感染中健康状况的新生物标志物。
