Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA.
Department of Chemistry, Villanova University, Villanova, PA 19085, USA.
FEMS Microbiol Ecol. 2021 Mar 10;97(3). doi: 10.1093/femsec/fiaa248.
Amphibians host diverse skin bacteria that have a role in pathogen defense, but these skin communities could change over time and impact this function. Here, we monitored individual Eastern red-spotted newts (Notophthalmus viridescens; N = 17) for 2 years in a field pond enclosure and assessed the effects of season and disturbance on skin bacterial community dynamics. We created disturbances by adding additional pond substrate to the enclosure at two timepoints. We planned to sample the skin bacterial community and metabolite profiles of each newt every 6 weeks; we ultimately sampled eight individuals at least six times. We used 16S rRNA gene amplicon sequencing to characterize the bacterial communities and HPLC-MS for metabolite profiling. We found that disturbance had a dramatic effect on skin bacterial communities and metabolite profiles, while season had an effect only using select metrics. There were seven core bacterial taxa (97% OTUs) that were found on all newts in all seasons, pre- and post-disturbance. Lastly, there was a correlation between bacterial and metabolite profiles post-disturbance, which was not observed pre-disturbance. This longitudinal study suggests that environmental disturbances can have lasting effects on skin bacterial communities that overwhelm seasonal changes, although the core bacteria remain relatively consistent over time.
两栖动物的皮肤携带有多种细菌，这些细菌在病原体防御中起着重要作用。然而，这些皮肤菌群可能会随着时间的推移而发生变化，并影响这一功能。在这里，我们对野外池塘围场内的 17 只东方红点蟾蜍（Notophthalmus viridescens）进行了为期 2 年的个体监测，并评估了季节和干扰对皮肤细菌群落动态的影响。我们通过在围场的两个时间点添加额外的池塘基质来制造干扰。我们计划每 6 周对每只蟾蜍的皮肤细菌群落和代谢物特征进行采样；最终，我们对至少 8 只个体进行了 6 次以上的采样。我们使用 16S rRNA 基因扩增子测序来描述细菌群落，并用 HPLC-MS 进行代谢物特征分析。我们发现干扰对皮肤细菌群落和代谢物特征有显著影响，而季节仅在使用特定指标时才有影响。在干扰前后的所有季节，我们都发现了 7 种核心细菌类群（97%的 OTUs）存在于所有蟾蜍的皮肤上。最后，在干扰后细菌和代谢物特征之间存在相关性，而在干扰前则没有观察到这种相关性。这项纵向研究表明，环境干扰可能对皮肤细菌群落产生持久影响，使其超越季节性变化，尽管核心细菌在时间上仍保持相对稳定。
