Berger Lee, Speare Rick, Skerratt Lee F
Amphibian Disease Ecology Group, School of Public Health, Tropical Medicine and Rehabilitation Sciences, James Cook University, Townsville, Queensland 4811, Australia.
Dis Aquat Organ. 2005 Dec 30;68(1):65-70. doi: 10.3354/dao068065.
Although histopathology is used routinely for diagnosis of chytridiomycosis in live and dead amphibians, there are no quantitative data on the distribution of the causative fungus, Batrachochytrium dendrobatidis, in the skin. We performed quantitative histological examinations on 6 sites on the body and 4 toes of 10 free-ranging adult green tree frogs Litoria caerulea found recently dead or dying from chytridiomycosis. Large numbers of sporangia occurred in all areas of ventral skin and toes; on average there were 94.3 sporangia mm(-1) of superficial epidermis. The number of sporangia was highly variable and this appeared to be related to the stage in the cycle of sloughing. The stratum corneum tends to build up with high intensities of infection and then sheds entirely rather than being shed continuously. Very few or no sporangia occurred on dorsal skin. This distribution could be explained by the dryness of the dorsal skin or possibly by the greater number of serous glands, which produce antifungal peptides, on the dorsum. In some frogs, ulceration and erosions occurred on skin on the back in the absence of sporangia. Other pathological changes such as hyperkeratosis and congestion occurred much more frequently on ventral surfaces.
尽管组织病理学通常用于诊断活体和死亡两栖动物的壶菌病，但对于致病真菌——蛙壶菌在皮肤中的分布尚无定量数据。我们对10只自由放养的成年绿树蛙（绿雨滨蛙）的身体6个部位和4个脚趾进行了定量组织学检查，这些蛙最近因壶菌病死亡或濒死。腹侧皮肤和脚趾的所有区域都出现了大量的孢子囊；平均每平方毫米浅表表皮有94.3个孢子囊。孢子囊的数量变化很大，这似乎与蜕皮周期的阶段有关。角质层往往在感染强度高时堆积，然后整体脱落，而不是持续脱落。背部皮肤很少或没有孢子囊。这种分布可能是由于背部皮肤干燥，或者可能是由于背部有更多产生抗真菌肽的浆液腺。在一些青蛙中，背部皮肤在没有孢子囊的情况下出现溃疡和糜烂。其他病理变化，如角化过度和充血，在腹侧表面更为常见。
