Assessing the ability of swab data to determine the true burden of infection for the amphibian pathogen Batrachochytrium dendrobatidis.
Assessing the ability of swab data to determine the true burden of infection for the amphibian pathogen Batrachochytrium dendrobatidis.
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DOI：
10.1007/s10393-016-1114-z
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发表时间：
2016-06
期刊：
影响因子：
2.5
通讯作者：
Fisher M
中科院分区：
文献类型：
--
作者：
Clare F;Daniel O;Garner T;Fisher M
Batrachochytrium dendrobatidis (Bd) 是一种致病真菌，通过感染两栖动物的表皮引起壶菌病。检测 Bd 最常用的方法是使用无菌拭子，擦拭两栖动物的角质化区域，然后进行处理以产生 DNA，用于 qPCR 检测。该方法已被用来推断某些物种的致命感染阈值；然而，拭子方法在检测个人真实感染负担方面的可靠性和可重复性尚不清楚。欧洲助产士蟾蜍（Alytes obstetricans）很容易感染壶菌病，并且在整个欧洲都高度被 Bd 寄生。通过量化整个皮肤的 Bd 负载，并将其与同一个体的拭子结果进行比较，我们确定表皮拭子是否能够提供可量化且准确的真实真菌负荷指示。此外，我们还检查了是否可以通过比较表现出不同临床状态的受感染产科放线菌的拭子数据来推断致死感染的阈值。从拭子数据中，我们发现与视觉健康的个体相比，垂死的变体的真菌负担明显更高；然而，这些拭子数据准确指示真实真菌负荷的能力并不可靠。这些数据表明，真菌负荷动态在这些场所的产科产妇疾病引起的死亡率中发挥着重要作用，但使用拭子数据来推断 Bd 相关死亡率的确切阈值可能是不适当的且具有误导性。
Batrachochytrium dendrobatidis (Bd) is a pathogenic fungus which causes the disease chytridiomycosis in amphibians by infecting the animals’ epidermis. The most commonly applied method for the detection of Bd is the use of a sterile swab, rubbed over the keratinized areas of an amphibian and then processed to yield DNA for detection by qPCR. This method has been used to infer a threshold of lethal infection in some species; however, how reliable and reproducible the swabbing method is at detecting the true burden of infection suffered by individuals is not known. European midwife toads, Alytes obstetricans, are susceptible to chytridiomycosis and are highly parasitised by Bd across Europe. By quantifying Bd-load throughout the entire skin and comparing this to swab results taken from the same individual, we determined whether epidermal swabs provide a quantifiable and accurate indication of the true fungal burden suffered. Further, we examined whether we could infer a threshold for lethal infection based on comparison of swab data taken from infected A. obstetricans exhibiting different clinical states. From swab data, we detected significantly higher fungal burdens from moribund metamorphs compared to visually healthy individuals; however, the ability of these swab data to provide an accurate indication of the true fungal burden was not reliable. These data suggest that fungal load dynamics play an important role in disease-induced mortality in A. obstetricans at these sites, but that using swab data to infer an exact threshold for Bd-associated mortality might be inappropriate and misleading.