Physiology of Batrachochytrium dendrobatidis, a chytrid pathogen of amphibians
Physiology of Batrachochytrium dendrobatidis, a chytrid pathogen of amphibians
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DOI：
10.2307/3761981
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发表时间：
2004-01-01
期刊：
影响因子：
2.8
通讯作者：
Longcore, JE
中科院分区：
文献类型：
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作者：
Piotrowski, JS;Annis, SL;Longcore, JE
树状壶菌 (Batrachochytrium dendrobatidis) 是两栖动物的一种病原体，与几个大陆的种群数量严重下降有关。我们研究了 B. dendrobatidis 的游动孢子活性、生理学和蛋白酶产生，以帮助了解这种病原体的流行病学。超过95%的游动孢子在24小时内停止移动，并在包囊前游动不到2厘米。 B. dendrobatidis 分离株在 425 C 的温度和 pH 4-8 的条件下生长和繁殖。生长在 17-25 C 和 pH 6-7 时达到最大。将培养物暴露于 30°C 8 天，杀死了 50% 的复制品。 B. dendrobatidis 培养物在高压灭菌的蛇皮和 1% 角蛋白琼脂上生长，但它们在胰蛋白胨或蛋白胨牛奶中生长最好，并且在胰蛋白胨中生长时不需要额外的糖。 B. dendrobatidis 产生细胞外蛋白酶，可降解酪蛋白和明胶，但对天蓝色角蛋白没有可测量的活性。这些蛋白酶在温度 6-37°C、pH 值 6-8 范围内对偶氮酪蛋白具有活性，在温度 23-30°C、pH 8 时活性最高。讨论了这些观察结果对疾病传播和发展的影响。
Batrachochytrium dendrobatidis is a pathogen of amphibians that has been implicated in severe population declines on several continents. We investigated the zoospore activity, physiology and protease production of B. dendrobatidis to help understand the epidemiology of this pathogen. More than 95% of zoospores stopped moving within 24 h and swam less than 2 cm before encysting. Isolates of B. dendrobatidis grew and reproduced at temperatures of 425 C and at pH 4-8. Growth was maximal at 17-25 C and at pH 6-7. Exposure of cultures to 30 C for 8 d killed 50% of the replicates. B. dendrobatidis cultures grew on autoclaved snakeskin and 1% keratin agar, but they grew best in tryptone or peptonized milk and did not require additional sugars when grown in tryptone. B. dendrobatidis produced extracellular proteases that degraded casein and gelatin but had no measurable activity against keratin azure. The proteases were active against azocasein at temperatures of 6-37 C and in a pH range of 6-8, with the highest activity at temperatures of 23-30 C and at pH 8. The implications of these observations on disease transmission and development are discussed.