我们已经研究了鳟鱼卵表面和成年鳟鱼皮肤上微生物群落的变化,这些变化与寄生虫的存在有关。这种病原体会导致腐性病,一种导致鲑鱼养殖场和孵化场重大损失的疾病。从其他疾病系统中已知,宿主相关的微生物组在防御病原体中起着至关重要的作用。但是如果病原体占主导地位,这可能会导致生态失调。然而,分析寄生链球菌对多样性的影响,composition,鱼皮和卵上的微生物群落功能很少。因此,我们从受伤和健康的鳟鱼(N=12)中收集了皮肤拭子,在寄生链球菌负荷方面有所不同,来自克罗地亚的三个不同的养鱼场(Kostanjevac,拉多万,和索林),而鳟鱼卵样本(N=12)在实验室中被寄生链球菌感染。Illumina对16SrRNA标记基因的V4区域进行测序显示,感染寄生链球菌降低了卵表面的微生物多样性,Pielou的均匀度和香农指数下降证明了这一点。我们进一步确定了在卵/皮肤样品中相对丰度>5.0%的细菌属是否以相对于寄生链球菌的存在显著不同的丰度存在。结果表明,一些属,如假单胞菌和黄杆菌,在卵表面存在病原体的情况下显着降低。另一方面,一些细菌类群,例如不动杆菌和Janthinobacterium,以及气单胞菌,在患病的卵和受伤的鳟鱼皮肤上更丰富,分别。最后,β多样性分析(加权UniFrac,未加权的UniFrac,Bray-Curtis)已经表明采样位置(即,养鱼场),随着寄生虫感染状况,对鳟鱼皮肤和卵的微生物群落组成也有显著影响,证明了环境对宿主表面微生物组形成的强烈影响。总的来说,我们已经表明,寄生链球菌的存在与鳟鱼皮肤/卵微生物组的多样性和结构的变化有关。所获得的结果可以支持开发水产养殖中腐殖质病的新策略。
We have investigated the changes in the microbial communities on the surface of
trout eggs and the skin of adult
trout in relation to the presence of Saprolegnia parasitica. This pathogen causes saprolegniosis, a disease responsible for significant losses in salmonid farms and hatcheries. It is known from other disease systems that the host-associated microbiome plays a crucial role in the defence against pathogens, but if the pathogen predominates, this can lead to dysbiosis. However, analyses of the effects of S. parasitica on the diversity, composition, and function of microbial communities on fish skin and eggs are scarce. Thus, we have collected skin swabs from injured and healthy
trout (N = 12), which differed in S. parasitica load, from three different fish farms in Croatia (Kostanjevac, Radovan, and Solin), while
trout egg samples (N = 12) were infected with S. parasitica in the laboratory. Illumina sequencing of the V4 region of the 16S rRNA marker gene showed that infection with S. parasitica reduced the microbial diversity on the surface of the eggs, as evidenced by decreased Pielou\'s evenness and Shannon\'s indices. We further determined whether the bacterial genera with a relative abundance of >5.0% in the egg/skin samples were present at significantly different abundances in relation to the presence of S. parasitica. The results have shown that some genera, such as Pseudomonas and Flavobacterium, decreased significantly in the presence of the pathogen on the egg surface. On the other hand, some bacterial taxa, such as Acinetobacter and Janthinobacterium, as well as Aeromonas, were more abundant on the diseased eggs and the injured
trout skin, respectively. Finally, beta diversity analyses (weighted UniFrac, unweighted UniFrac, Bray-Curtis) have shown that the sampling location (i.e., fish farm), along with S. parasitica infection status, also has a significant influence on the microbial communities\' composition on the trout skin and eggs, demonstrating the strong influence of the environment on the shaping of the host surface microbiome. Overall, we have shown that the presence of S. parasitica was associated with changes in the diversity and structure of the trout skin/egg microbiome. The results obtained could support the development of new strategies for the management of saprolegniosis in aquaculture.