Martínez-Ugalde Emanuel, Ávila-Akerberg Víctor, González Martínez Tanya M, Vázquez Trejo Montserrat, Zavala Hernández Dalia, Anaya-Morales Sara Lucia, Rebollar Eria A
Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico.
Instituto de Ciencias Agropecuarias y Rurales, Universidad Autónoma del Estado de México, Toluca, Mexico.
Anim Microbiome. 2022 Dec 12;4(1):63. doi: 10.1186/s42523-022-00215-7.
Microbiomes have been increasingly recognized as major contributors to host health and survival. In amphibians, bacterial members of the skin microbiota protect their hosts by inhibiting the growth of the fungal pathogen Batrachochytrium dendrobatidis (Bd). Even though several studies describe the influence of biotic and abiotic factors over the skin microbiota, it remains unclear how these symbiotic bacterial communities vary across time and development. This is particularly relevant for species that undergo metamorphosis as it has been shown that host physiology and ecology drastically influence diversity of the skin microbiome.
We found that the skin bacterial communities of the axolotl A. altamirani are largely influenced by the metamorphic status of the host and by seasonal variation of abiotic factors such as temperature, pH, dissolved oxygen and conductivity. Despite high Bd prevalence in these samples, the bacterial diversity of the skin microbiota did not differ between infected and non-infected axolotls, although relative abundance of particular bacteria were correlated with Bd infection intensity.
Our work shows that metamorphosis is a crucial process that shapes skin bacterial communities and that axolotls under different developmental stages respond differently to environmental seasonal variations. Moreover, this study greatly contributes to a better understanding of the factors that shape amphibian skin microbiota, especially in a largely underexplored group like axolotls (Mexican Ambystoma species).
微生物群落日益被认为是宿主健康和生存的主要贡献者。在两栖动物中，皮肤微生物群的细菌成员通过抑制真菌病原体蛙壶菌（Bd）的生长来保护宿主。尽管有几项研究描述了生物和非生物因素对皮肤微生物群的影响，但这些共生细菌群落如何随时间和发育而变化仍不清楚。这对于经历变态发育的物种尤为重要，因为已有研究表明宿主的生理和生态会极大地影响皮肤微生物群的多样性。
我们发现，墨西哥钝口螈（A. altamirani）的皮肤细菌群落很大程度上受到宿主变态状态以及温度、pH值、溶解氧和电导率等非生物因素季节性变化的影响。尽管这些样本中蛙壶菌的感染率很高，但感染和未感染的墨西哥钝口螈皮肤微生物群的细菌多样性并无差异，不过特定细菌的相对丰度与蛙壶菌感染强度相关。
我们的研究表明变态发育是塑造皮肤细菌群落的关键过程，处于不同发育阶段的墨西哥钝口螈对环境季节性变化的反应不同。此外，本研究极大地有助于更好地理解塑造两栖动物皮肤微生物群的因素，尤其是在像墨西哥钝口螈（墨西哥钝口螈属物种）这样研究较少的群体中。
