Sun Dan, Ellepola Gajaba, Herath Jayampathi, Liu Hong, Liu Yewei, Murray Kris, Meegaskumbura Madhava
Guangxi Key Laboratory for Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, Guangxi, 530000, People's Republic of China.
Department of Zoology, Faculty of Science, University of Peradeniya, Peradeniya, KY20400, Sri Lanka.
Ecohealth. 2025 Mar;22(1):91-107. doi: 10.1007/s10393-025-01698-x. Epub 2025 Jan 27.
Chytridiomycosis is a wildlife disease that has caused significant declines in amphibian populations and species extinctions worldwide. Asia, where the causal pathogens Batrachochytrium dendrobatidis (Bd) and B. salamndrivorans (Bsal) originated, has not witnessed mass die-offs. It is hypothesized that Asian amphibians may have evolved immunity to clinical Batrachochytrium infection, but this has not been explored in depth due to limited knowledge of endemic lineages and infection patterns. We investigated Bd's genetic diversity and infection patterns in south China's Guangxi region using the internal transcribed spacer (ITS) marker and nested PCR. Across the 17 forest sites studied (N = 1088 individuals; 1012 adults and 76 tadpoles), the overall prevalence of Bd infection was 4.74% in adult individuals and 5.26% in tadpoles. We found seven new haplotypes, four of which were closely related to the BdASIA-1 lineage from South Korea. The most prevalent haplotype (genetically similar to BdASIA-3) was found in 11 out of 15 infected species, including a salamander with non-lethal skin lesions. A generalized linear model of our environmental data indicates that Bd infection is correlated with mean temperature of the warmest quarter and elevation, with higher infection prevalence associated with lower temperature and relatively higher elevation in southern China. Our findings suggest significant undiscovered genetic diversity of Asian Bd lineages in this region. Longer-term studies are required to further investigate Bd diversity, prevalence, seasonality, and impact on native species and populations in Southern China and across the region of origin in Asia.
蛙壶菌病是一种野生动物疾病，已导致全球两栖动物数量大幅下降和物种灭绝。亚洲是致病病原体蛙壶菌（Batrachochytrium dendrobatidis，Bd）和蝾螈壶菌（B. salamndrivorans，Bsal）的起源地，但尚未出现大规模死亡事件。据推测，亚洲两栖动物可能已经进化出对临床蛙壶菌感染的免疫力，但由于对本地谱系和感染模式的了解有限，这一点尚未得到深入研究。我们使用内部转录间隔区（ITS）标记和巢式PCR技术，调查了中国南方广西地区蛙壶菌的遗传多样性和感染模式。在研究的17个森林地点（N = 1088只个体；1012只成体和76只蝌蚪）中，蛙壶菌感染的总体患病率在成体个体中为4.74%，在蝌蚪中为5.26%。我们发现了7个新的单倍型，其中4个与来自韩国的BdASIA - 1谱系密切相关。在15种受感染物种中的11种中发现了最常见的单倍型（与BdASIA - 3基因相似），包括一只患有非致命性皮肤损伤的蝾螈。我们环境数据的广义线性模型表明，蛙壶菌感染与最暖季度的平均温度和海拔高度相关，在中国南方，感染患病率较高与较低温度和相对较高海拔有关。我们的研究结果表明，该地区亚洲蛙壶菌谱系存在尚未被发现的显著遗传多样性。需要进行长期研究，以进一步调查中国南方及亚洲起源地区蛙壶菌的多样性、患病率、季节性以及对本地物种和种群的影响。
