Rajarajan Amruta, Decaestecker Ellen, Bulteel Lore, Walser Jean-Claude, Spaak Piet, Wolinska Justyna
Department of Aquatic Ecology, Swiss Federal Institute of Aquatic Science and Technology (Eawag) Dübendorf, Zürich, Switzerland.
Dept. of Evolutionary and Integrative Ecology, Leibniz Institute for Freshwater Ecology and Inland Fisheries, Berlin, Germany.
Parasitology. 2024 Sep;151(10):1137-1147. doi: 10.1017/S0031182024000787. Epub 2024 Nov 15.
Host–bacterial communities (microbiomes) are influenced by a wide range of factors including host genotype and parasite exposure. However, few studies disentangle temporal and host-genotype-specific variation in microbiome response to infection across several host tissues. We experimentally exposed the freshwater crustacean to its fungal parasite and characterized changes in host–bacterial communities associated with the parasite's development within the host. We used 16S rRNA gene sequencing to assess bacterial communities of the host (a) 24 h (‘initial parasite exposure’) and (b) 10 days (‘successful infection’) after exposure to a standard dose of spores, in host guts, body tissue (excluding guts) and whole individuals. We also investigated whether bacterial community responses to parasite exposure varied by host genotype.Parasite exposure did not immediately alter host gut bacterial communities, but drove host-genotype-specific changes in the bacterial community composition of whole individuals. We validated that these changes were not driven by shifts in bacterial communities of the culturing medium, due to the addition of the parasite spore solution. Successful infection (i.e. the proliferation of spores in the host body) reduced alpha diversity and shifted abundance of dominant bacterial orders in the gut. Moreover, it induced a host-genotype-specific changes in body bacterial community composition. Overall, bacterial community responses to parasite exposure and subsequent infection are complex: they occur in a host-genotype-dependent manner, differentially at distinct timepoints after parasite exposure, and in specific host tissue.
宿主-细菌群落（微生物组）受到多种因素的影响，包括宿主基因型和寄生虫暴露。然而，很少有研究能够厘清微生物组对感染的反应在时间上以及宿主基因型特异性方面的变化，且涉及多个宿主组织。我们通过实验将淡水甲壳类动物暴露于其真菌寄生虫，并描述了与寄生虫在宿主体内发育相关的宿主-细菌群落变化。我们使用16S rRNA基因测序来评估宿主在接触标准剂量的孢子后（a）24小时（“初次寄生虫暴露”）和（b）10天（“成功感染”）时，宿主肠道、身体组织（不包括肠道）和整个个体中的细菌群落。我们还研究了细菌群落对寄生虫暴露的反应是否因宿主基因型而异。寄生虫暴露并未立即改变宿主肠道细菌群落，但驱动了整个个体细菌群落组成的宿主基因型特异性变化。我们验证了这些变化不是由于添加寄生虫孢子溶液导致培养基细菌群落的变化所驱动的。成功感染（即孢子在宿主体内增殖）降低了肠道内的α多样性并改变了优势细菌菌目的丰度。此外，它还诱导了身体细菌群落组成的宿主基因型特异性变化。总体而言，细菌群落对寄生虫暴露和后续感染的反应是复杂的：它们以宿主基因型依赖的方式发生，在寄生虫暴露后的不同时间点以及特定宿主组织中存在差异。
