Role of cold shock protein CspA insubsp.physiology and virulence.

Abstract

Cold shock proteins are small, highly conserved nucleic acid-binding proteins that help bacteria adapt to stress conditions.subspeciesis a psychotropic, Gram-negative intracellular fish pathogen that causes furunculosis in fish. The role of cold shock proteins in the stress response in marine pathogens likeis unknown. In this study, we reported the role of cold shock protein A (CspA) inphysiology, stress response, and virulence in lumpfish ().Δwas characterized using phenotypic tests and transcriptomics.Δshowed a reduction in survival at low temperatures (0 and 4 °C) and in ox bile-containing (5%) conditions. Differential gene expression analysis showed 632 dysregulated genes in ΔAmong these 632 differentially expressed genes (DEGs), 413 were upregulated, and 219 were downregulated. Most downregulated genes were related to the type III secretion system (T3SS). However,Δwas not fully attenuated in the lumpfish host but delayed fish mortality and reduced tissue colonization after systemic infection in contrast to the wild type strain. Overall, this study provides novel insight into the roles of CspA in virulence and the physiology of.