Costa Sara, Proença Diogo Neves, Alves Artur, Morais Paula V, Lopes Isabel
Centre for Environmental and Marine Studies (CESAM), Department of Biology, Campus of Santiago, University of Aveiro, 3810-193 Aveiro, Portugal.
MED-Mediterranean Institute for Agriculture, Environment and Development & CHANGE-Global Change and Sustainability Institute, Faculdade de Ciências e Tecnologia, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal.
J Fungi (Basel). 2025 Sep 2;11(9):649. doi: 10.3390/jof11090649.
Amphibian populations have experienced a severe decline over the past 40 years, driven primarily by environmental pollution, habitat destruction, climate change, and disease. This work reports, for the first time, saprolegniosis in egg masses and saprolegniosis in amphibians in Portugal. After isolation and phylogenetic analysis, the pathogen was identified as . Following this, the present work intended to screen a collection of skin bacteria for the existence of bacterial strains with inhibitory action against the newly identified SC1 and two other species, SAP 1010 UE and SAP 1581 UE. The results showed that various bacterial species could inhibit the growth of these three species of oomycetes. Bacteria with the most significant antagonistic action against spp. predominantly belonged to the genus , followed by , , and . Despite variations in bacterial diversity among frog populations, the present study also demonstrated the presence of bacteria on frogs' skin that were capable of inhibiting spp., as evidenced by challenge assays. These findings highlight the protective function of bacteria present in amphibian skin. The observed bacterial diversity may contribute to the metabolic redundancy of the frog skin microbiome, helping to maintain its functional capacity despite shifts in the community composition. Additionally, the study found that, when providing a more advantageous environment for pathogen growth-in this case a peptone-glucose (PG) medium instead of R2A-the percentage of bacteria with moderate-to-strong antagonistic activity dropped by 13% to 4%. In conclusion, the presence of bacteria capable of inhibiting spp. in adult individuals and across different environmental conditions may contribute to lowering the susceptibility of frog adults towards spp., compared with that in the early stages of development, like the tadpole or egg stages.
在过去40年里，两栖动物种群数量急剧下降，主要原因是环境污染、栖息地破坏、气候变化和疾病。这项研究首次报告了葡萄牙卵块中的水霉病以及两栖动物身上的水霉病。经过分离和系统发育分析，病原体被鉴定为 。在此之后，本研究旨在筛选一批青蛙皮肤细菌，寻找对新鉴定的SC1以及另外两个物种SAP 1010 UE和SAP 1581 UE具有抑制作用的细菌菌株。结果表明，多种细菌物种能够抑制这三种卵菌的生长。对 spp. 具有最显著拮抗作用的细菌主要属于 属，其次是 属、 属和 属。尽管不同青蛙种群的细菌多样性存在差异，但本研究也证明了青蛙皮肤上存在能够抑制 spp. 的细菌，攻毒试验证明了这一点。这些发现突出了两栖动物皮肤中细菌的保护作用。观察到的细菌多样性可能有助于青蛙皮肤微生物群的代谢冗余，尽管群落组成发生变化，但仍有助于维持其功能能力。此外，研究发现，当为病原体生长提供更有利的环境时——在本案例中是蛋白胨 - 葡萄糖（PG）培养基而非R2A培养基——具有中度至强拮抗活性的细菌百分比从13%降至4%。总之，与蝌蚪或卵等发育早期阶段相比，成年个体以及不同环境条件下都存在能够抑制 spp. 的细菌，这可能有助于降低成年青蛙对 spp. 的易感性。
