Su Rui, Zhang Sheng, Zhang Xueying, Wang Shengnan, Zhang Wenya
Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China.
Environ Sci Pollut Res Int. 2023 Feb;30(9):22330-22342. doi: 10.1007/s11356-022-23803-1. Epub 2022 Oct 26.
Amphibians defend against pathogens using skin microbial communities, in addition to innate and adaptive immunity. Despite skin microbial communities play a key role in the immune function of amphibians, few studies have focused on the changes in its composition and function. In the present study, we identified the variation in adaptive immunity, as well as the corresponding changes in skin microbiome of Bufo raddei living in a heavy metal polluted area. The adaptive immunity of B. raddei in heavy metal polluted area was significantly lower than that in relatively unpolluted area. Further, different skin bacterial communities were found in the two areas. In the heavy metal polluted area, Actinobacteria and Microbacterium were the dominant bacteria in the skin microbiome of B. raddei, which showed broad-spectrum antibacterial activity. Besides, the antibiotic synthesis was also increased in metabolic pathways. The present study suggested that the adaptive immunity of B. raddei was weakened under long-term heavy metal stress. However, the toads increased the abundance of bacteriostatic bacteria by regulating the composition of skin microbiome, which released a large number of bacteriostatic metabolites and enhanced the host resistance to external pathogens in turn.
除了先天免疫和适应性免疫外，两栖动物还利用皮肤微生物群落抵御病原体。尽管皮肤微生物群落在两栖动物的免疫功能中起着关键作用，但很少有研究关注其组成和功能的变化。在本研究中，我们确定了生活在重金属污染地区的中华大蟾蜍适应性免疫的变化，以及其皮肤微生物群的相应变化。重金属污染地区中华大蟾蜍的适应性免疫显著低于相对未污染地区。此外，在这两个地区发现了不同的皮肤细菌群落。在重金属污染地区，放线菌和微杆菌是中华大蟾蜍皮肤微生物群中的优势细菌，它们具有广谱抗菌活性。此外，代谢途径中的抗生素合成也有所增加。本研究表明，长期重金属胁迫下中华大蟾蜍的适应性免疫减弱。然而，蟾蜍通过调节皮肤微生物群的组成增加了抑菌细菌的丰度，这些细菌释放大量抑菌代谢产物，进而增强了宿主对外界病原体的抵抗力。
