Phage Shock Protein-Mediated Stress Response in Bacteria

Phage shock protein (Psp) is a response to envelope stress encountered by bacteria. Though first discovered and named after its synthesis in Escherichia coli in response to filamentous phage infection, this defense response is not specific to phage attack. Instead, different conditions like heat, osmotic shock, mislocalization of outer membrane secretins, and stored-curvature-elastic stress can induce the Psp-mediated stress response. The components of the Psp response system have been studied in bacteria, archaea, and even in plant chloroplasts. Studies have shown the implications of phage shock protein response in survival, phenotypic variation, virulence, biofilm formation, and antibiotic resistance in the context of pathogenic bacteria. In the present global scenario, the challenge of antimicrobial resistance in pathogenic bacteria is of significant concern. In this regard, understanding the stress response and mitigation systems in those bacteria becomes crucial. This chapter focuses on the current understanding of the phage shock protein-mediated stress response systems, stimuli involved, and the contribution of the different Psp components towards survival, associated virulence, biofilm formation, antibiotic resistance, and persister formation in various bacterial pathogens.