Cohen Carmit, Toh Evelyn, Munro Daniel, Dong Qunfeng, Hawlena Hadas
Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN, USA.
ISME J. 2015 Jul;9(7):1662-76. doi: 10.1038/ismej.2014.255. Epub 2015 Jan 9.
Vector-borne microbes are subject to the ecological constraints of two distinct microenvironments: that in the arthropod vector and that in the blood of its vertebrate host. Because the structure of bacterial communities in these two microenvironments may substantially affect the abundance of vector-borne microbes, it is important to understand the relationship between bacterial communities in both microenvironments and the determinants that shape them. We used pyrosequencing analyses to compare the structure of bacterial communities in Synosternus cleopatrae fleas and in the blood of their Gerbillus andersoni hosts. We also monitored the interindividual and seasonal variability in these bacterial communities by sampling the same individual wild rodents during the spring and again during the summer. We show that the bacterial communities in each sample type (blood, female flea or male flea) had a similar phylotype composition among host individuals, but exhibited seasonal variability that was not directly associated with host characteristics. The structure of bacterial communities in male fleas and in the blood of their rodent hosts was remarkably similar and was dominated by flea-borne Bartonella and Mycoplasma phylotypes. A lower abundance of flea-borne bacteria and the presence of Wolbachia phylotypes distinguished bacterial communities in female fleas from those in male fleas and in rodent blood. These results suggest that the overall abundance of a certain vector-borne microbe is more likely to be determined by the abundance of endosymbiotic bacteria in the vector, abundance of other vector-borne microbes co-occurring in the vector and in the host blood and by seasonal changes, than by host characteristics.
节肢动物媒介中的微环境及其脊椎动物宿主血液中的微环境。由于这两种微环境中细菌群落的结构可能会极大地影响媒介传播微生物的丰度，因此了解这两种微环境中细菌群落之间的关系以及塑造它们的决定因素非常重要。我们使用焦磷酸测序分析来比较埃及扁蚤及其宿主安德森更格卢鼠血液中细菌群落的结构。我们还通过在春季和夏季对同一只野生啮齿动物个体进行采样，监测了这些细菌群落的个体间和季节变异性。我们发现，每种样本类型（血液、雌性跳蚤或雄性跳蚤）中的细菌群落在宿主个体间具有相似的系统发育型组成，但表现出与宿主特征无直接关联的季节变异性。雄性跳蚤及其啮齿动物宿主血液中的细菌群落结构非常相似，主要由跳蚤传播的巴尔通体和支原体系统发育型主导。雌性跳蚤中的细菌群落与雄性跳蚤和啮齿动物血液中的细菌群落相比，跳蚤传播细菌的丰度较低且存在沃尔巴克氏体系统发育型。这些结果表明，某种媒介传播微生物的总体丰度更可能由媒介中内共生细菌的丰度、在媒介和宿主血液中同时出现的其他媒介传播微生物的丰度以及季节变化决定，而非宿主特征。
