Intestinal microbiome-mediated resistance against vibriosis for Cynoglossus semilaevis

Abstract

Background Infectious diseases have caused huge economic loss and food security issues in fish aquaculture. Current management and breeding strategies heavily rely on the knowledge of regulative mechanisms underlying disease resistance. Though the intestinal microbial community was linked with disease infection, there is little knowledge about the roles of intestinal microbes in fish disease resistance. Cynoglossus semilaevis is an economically important and widely cultivated flatfish species in China. However, it suffers from outbreaks of vibriosis, which results in huge mortalities and economic loss. Results Here, we used C. semilaevis as a research model to investigate the host-microbiome interactions in regulating vibriosis resistance. The resistance to vibriosis was reflected in intestinal microbiome on both taxonomic and functional levels. Such differences also influenced the host gene expressions in the resistant family. Moreover, the intestinal microbiome might control the host immunological homeostasis and inflammation to enhance vibriosis resistance through the microbe-intestine-immunity axis. For example, Phaeobacter regulated its hdhA gene and host cyp27a1 gene up-expressed in bile acid biosynthesis pathways, but regulated its trxA gene and host akt gene down-expressed in proinflammatory cytokines biosynthesis pathways, to reduce inflammation and resist disease infection in the resistant family. Furthermore, the combination of intestinal microbes and host genes as biomarkers could accurately differentiate resistant family from susceptible family. Conclusion Our study uncovered the regulatory patterns of the microbe-intestine-immunity axis that may contribute to vibriosis resistance in C. semilaevis. These findings could facilitate the disease control and selective breeding of superior germplasm with high disease resistance in fish aquaculture.

Effects of cysteine addition to low-fishmeal diets on the growth, anti-oxidative stress, intestine immunity, and Streptococcus agalactiae resistance in juvenile golden pompano (Trachinotus ovatus)

“…Similarly, our results showed that exogenous cysteine supplementation at 0.6% and 1.2% greatly improved intestinal villus length and muscular thickness, thus effectively alleviating the weakening of the intestinal physical barrier associated with low-fishmeal diets. Alterations in the intestinal physical barrier typically accompany changes in the abundance of intestinal flora ( 52 , 53 ) and expression of intestinal immune-related genes ( 54 ). Therefore, we propose that the protective effect of cysteine on the intestinal physical barrier of golden pompano may be correlated with increased abundance of intestinal flora and high expression of intestinal antioxidant stress- and immune-related genes.…”

“…Maintaining the diversity and abundance of intestinal flora is essential for the intestinal health of fish, and disturbances to the intestinal flora tend to damage the physical barrier of the intestine and elicit inflammatory responses ( 53 , 55 ). In our study, alpha and beta diversity analysis of the intestinal flora showed that supplementation of the diet with cysteine regulated the abundance and diversity and improved the structure of intestinal flora in golden pompano.…”

Histological, microecological and transcriptomic physiological responses underlying hypoxia and reoxygenation adaptation in yellowtail kingfish (Seriola lalandi)

“…Further analysis showed that pathways, including Glycan biosynthesis and metabolism, Digestive system, Signaling molecules and interaction, and Nervous system, are all related to energy metabolism and cell molecular signal. Zhou et al (2022) showed that the gastrointestinal microbiome could affect the resistance of Cynoglossus semilaevis by regulating host metabolism and signaling pathways. Additionally, a previous study on mammals showed a higher abundance of intestinal Bacteroidota and Firmicutes in hypoxia, which suggested that intestinal bacteria may be involved in host energy metabolism and facilitate organismal adaptation to hypoxic environments (Foley et al, 2016).…”

“…Effects of hypoxia on the intestinal microflora of juvenile cobia (Rachycentron canadum) showed that the richness and diversity of intestinal microflora significantly changed in response to hypoxic stress; additionally, the structure of the intestinal microbial population was altered (Wang et al, 2021). Some studies have proposed that gastrointestinal microbiota participate in the immune and metabolic processes by participating in some signaling pathways in vertebrates (Ramıŕez et al, 2020;Zhou et al, 2022). The interaction mechanism between gastrointestinal microorganisms and host gene regulation has provided a deeper insight into the adaptation mechanism of physiological changes in the organism in recent years (Ursell et al, 2014;de Vos et al, 2022).…”

Strategies for Prevention and Control of Vibriosis in Asian Fish Culture

“…At present, the mainly used identification methods are still conventional physiological, biochemical analyses, 16S rDNA sequencing and drug sensitivity test. In addition to these widely used assays, some convenient, fast and highly sensitive detection methods have been developed in recent years, for example, the identification of biomarkers based on host genes [ 7 ], exosomic miRNAs [ 8 ] and so on.…”