Coral reefs worldwide are rapidly declining due to increasing anthropogenic stressors and environmental changes, with large-scale mortalities of coral reefs observed in many locations across the globe. It has become clear that the microbiome of corals is important in understanding the causes of coral infections, although its exact role is yet to be fully understood. Here, we characterize the bacteria and fungi associated with the non-lesional and lesional (identified by discoloration and tissue loss) tissues of coral species from Vietnam. Metabarcoding of the bacterial 16S rRNA gene and the fungal ITS rRNA gene region were performed. We sampled across two Porites species with potentially multiple causes of stresses, yet the bacterial compositions of lesional regions were consistently different from non-lesional areas of the same coral. These differences were driven by a considerable and significant increase in OTU richness within the lesional region compared to the non-lesional region. While no single OTU was consistently associated with lesional tissue, indicator analysis revealed that nine OTUs were significantly more persistent in the lesional regions that could represent useful bioindicators of stress. Meanwhile, there were no indicator OTUs in the non-lesional region. Further investigations are needed to determine whether changing bacterial communities play a mechanistic role in inducing lesioning, or are opportunistically colonizing stressed corals.

中文翻译：

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与 Porites spp 内病变相关的细菌丰富度增加。越南

由于人为压力增加和环境变化，全世界的珊瑚礁正在迅速减少，在全球许多地方都观察到珊瑚礁的大规模死亡。很明显，珊瑚的微生物组对于了解珊瑚感染的原因很重要，尽管其确切作用尚未完全了解。在这里，我们描述了与越南珊瑚物种的非损伤和损伤（通过变色和组织损失识别）组织相关的细菌和真菌。对细菌 16S rRNA 基因和真菌 ITS rRNA 基因区域进行了元条形码编码。我们采样了两个具有多种压力原因的 Porites 物种，但损伤区域的细菌组成与同一珊瑚的非损伤区域始终不同。与非病变区域相比，病变区域内 OTU 丰富度的显着增加导致了这些差异。虽然没有单一的 OTU 始终与病变组织相关，但指标分析显示，九个 OTU 在病变区域的持久性明显更高，这可能代表有用的压力生物指标。同时，在非病变区域没有指示性OTU。需要进一步调查以确定不断变化的细菌群落是否在诱导损伤方面发挥了机械作用，或者是否有机会殖民压力珊瑚。指标分析显示，九个 OTU 在可能代表压力的有用生物指标的病变区域中显着更持久。同时，在非病变区域没有指示性OTU。需要进一步调查以确定不断变化的细菌群落是否在诱导损伤方面发挥了机械作用，或者是否有机会殖民压力珊瑚。指标分析显示，九个 OTU 在可能代表压力的有用生物指标的病变区域中显着更持久。同时，在非病变区域没有指示性OTU。需要进一步调查以确定不断变化的细菌群落是否在诱导损伤方面发挥了机械作用，或者是否有机会殖民压力珊瑚。