Transcriptome Analysis of Immune Response against Streptococcus agalactiae Infection in the Nile Tilapia GIFT Strain

Streptococcus agalactiae (group B streptococcus, GBS), a broad-spectrum pathogen, causes great economic losses in fish aquaculture, especially the industry of tilapia. Until now, knowledge immune response mechanism against S. infection tilapia has been limited. In present study, gill transcriptome from GBS and phosphate buffered saline (PBS) groups were sequenced. The transcriptomic analysis results presented differentially expressed genes (DEGs) at different time points (DEGs number, 6 h: 2122, 9 1851, 15 1791, 18 2395) after injection, significantly enriched immune-related gene ontology (GO) terms such as innate response. pathways included Toll-like receptor signaling pathway, nucleotide oligomerization domain (NOD)-like cytosolic-DNA sensing intestinal network for Immunoglobulin A (IgA) production. Most DEGs signaling, NOD-like upregulations h, which indicated that activated. Two (phagosome cell adhesion molecules) all points, suggesting these two might also play important roles infection. HE staining showed gills damaged seriously h post-infection, be due to possibility pyroptosis resulting changes pathway. This study provided new insight into mechanisms damage infected with agalactiae.