Biological functions of tolA in Aeromonas hydrophila

Abstract:

Aeromonas hydrophila is a pathogen that can infect both fish and mammals, including humans. Objective To construct the tolA-deleted strain of A. hydrophila ATCC 7966 and use this strain to explore the biological functions of tolA. Methods We constructed the tolA-deleted strain AhΔ tolA by homologous recombination and characterized the physiological phenotype of AhΔ tolA. Transcriptome sequencing was performed to compare the gene expression between the wild type (WT) and AhΔ tolA. Results The cell morphology of AhΔ tolA was changed. The deletion of tolA significantly enhanced the sensitivity to sodium deoxycholate and oxidative stress, while significantly reducing the biofilm formation and the expression levels of several virulence genes. The yield of outer membrane vesicles was significantly increased in AhΔ tolA. Transcriptomic analysis data showed that a total of 300 differentially expressed genes (DEGs) were screened between WT and AhΔ tolA, including 171 genes with up-regulated expression and 129 genes with down-regulated expression. GO enrichment analysis showed that the DEGs were mainly enriched in the oxidation-reduction process, metabolic process, outer membrane, and oxidoreductase activity. KEGG pathway enrichment analysis showed that the DEGs were mainly enriched in the biosynthesis of secondary metabolites, microbial metabolism in diverse environments, biosynthesis of cofactors, and biosynthesis of amino acids. Conclusion This study gives an insight into the roles of tolA in A. hydrophila and provides information about the metabolic pathways involving tolA. These results provide a theoretical reference for the prevention and control of A. hydrophila.