Aeromonas salmonicida subsp. Masoucida causes an emerging infectious diseases and immune response in red swamp crayfish (Procambarus clarkii)

In this study, the characteristics of a dominant strain wx3 isolated from the tissues of several sick red swamp crayfish were studied, and the immune response of the red swamp crayfish under stress was analyzed. The whole genome analysis of wx3 identified it as Aeromonas salmonicida subsp. Masoucida, which was confirmed using the bacterial challenge test, and is the pathogen that causes red swamp crayfish head rot. The sensitivity of wx3 to a variety of antibiotics was found that wx3 was highly sensitive to 13 antibiotics, but was not sensitive to 4 an-tibiotics. Comparative transcriptome analysis showed that 811 differentially expressed genes (DEGs) were enriched in the hepatopancreas 48 h after wx3 infection. The KEGG pathway analysis and GO analysis detected differentially expressed immune related genes, including C-type lectin 3 and Hsp22, which were upregulated, and also enriched in immune related pathways, such as the C-type lectin receptor signaling pathway, etc. In conclusion, by analyzing transcriptome, we found that red swamp crayfish infected with wx3 can exert a strong immune response.