温度骤变对日本医蛭肠道菌群的影响

Effects of acute temperature stress on intestinal microflora in Hirudo nipponia

目的研究急性温度应激条件下日本医蛭肠道微生物菌群多样性的组成及变化。方法选取健康日本医蛭200尾,设置对照组与试验组(各100尾),对照组25℃水体温度饲养、试验1组养殖水体温度急剧降温(30℃→4℃)、试验2组养殖水体温度急剧升温(4℃→25℃)。采用高通量测序技术分别研究对照组和试验组的日本医蛭肠道菌群特征及多样性变化。结果门分类水平上,日本医蛭肠道核心主导菌群为变形菌门(Proteobacteria)、拟杆菌门(Bacteroidetes)和厚壁菌门(Firmicutes);属分类水平上,温度急剧变化后,气单胞菌属(Aeromonas)丰度显著增加,Mucinivorans丰度显著减少,脱硫弧菌属(Desulfovibrio)丰度减少。结论温度骤变对日本医蛭肠道主导菌多样性组成及丰度产生了一定的影响,有害致病菌增加,有益菌减少,从而最终导致水蛭出现病态及死亡现象。本研究对于指导人工养殖实践、日本医蛭药材资源可持续利用以及深入开展肠道微生物分子调控机制研究都具有重要的理论和实践意义。

Objective To explore the composition and changes of intestinal microbiota of Hirudo nipponia under acute temperature stress. Methods Healthy leeches were divided into the control group(25 ℃), treatment group 1(from 30 ℃ to 4 ℃) or treatment group 2(from 4 ℃ to 25 ℃). The high-throughput sequencing technology were utilized to observe the leeches′ intestinal microflora. Results At the phylum level, the predominant intestinal flora in H. nipponia were Proteobacteria, Bacteroidetes and Firmicutes;At the genus level, the abundance of Aeromonas increased while the abundances of Mucinivorans and Desulfovibrio decreased under acute temperature stress. Conclusion Acute temperature stress has an effect on the diversity and abundance of the predominant intestinal microflora of H.nipponia, resulting in an increase of harmful bacteria and a decrease of beneficial bacteria which, consequently, lead to the sickness and death of the leeches. This result will be of great significance both in theory and in practice to the artificial breeding and sustainable use of H. nipponia as a medicinal material, and to further research on the molecular mechanism of intestinal microbial regulation.