<i>Listeria monocytogenes</i> Cold Shock Proteins: Small Proteins with A Huge Impact

• Main Authors: Francis Muchaamba, Roger Stephan, Taurai Tasara
• Format: Article
• Language: English
• Published: MDPI AG 2021-05-01
• Series: Microorganisms
• Subjects: cold shock protein; cold; osmotic; stress tolerance; virulence; biofilm
• Online Access: https://www.mdpi.com/2076-2607/9/5/1061

<i>Listeria monocytogenes</i> has evolved an extensive array of mechanisms for coping with stress and adapting to changing environmental conditions, ensuring its virulence phenotype expression. For this reason, <i>L. monocytogenes</i> has been identified as a significant food safety and public health concern. Among these adaptation systems are cold shock proteins (Csps), which facilitate rapid response to stress exposure. <i>L. monocytogenes</i> has three highly conserved <i>csp</i> genes, namely, <i>cspA</i>, <i>cspB</i>, and <i>cspD</i>. Using a series of <i>csp</i> deletion mutants, it has been shown that <i>L. monocytogenes</i> Csps are important for biofilm formation, motility, cold, osmotic, desiccation, and oxidative stress tolerance. Moreover, they are involved in overall virulence by impacting the expression of virulence-associated phenotypes, such as hemolysis and cell invasion. It is postulated that during stress exposure, Csps function to counteract harmful effects of stress, thereby preserving cell functions, such as DNA replication, transcription and translation, ensuring survival and growth of the cell. Interestingly, it seems that Csps might suppress tolerance to some stresses as their removal resulted in increased tolerance to stresses, such as desiccation for some strains. Differences in <i>csp</i> roles among strains from different genetic backgrounds are apparent for desiccation tolerance and biofilm production. Additionally, hierarchical trends for the different Csps and functional redundancies were observed on their influences on stress tolerance and virulence. Overall current data suggest that Csps have a wider role in bacteria physiology than previously assumed.