Cold-Shock Domain Family Proteins (Csps) Are Involved in Regulation of Virulence, Cellular Aggregation, and Flagella-Based Motility in Listeria monocytogenes

Abstract

Cold shock-domain family proteins (Csps) are highly conserved nucleic acid binding proteins regulating the expression of various genes including those involved in stress resistance and virulence in bacteria. We show here that Csps are involved in virulence, cell aggregation and flagella-based extracellular motility of Listeria monocytogenes. A L. monocytogenes mutant deleted in all three csp genes (ΔcspABD) is attenuated with respect to human macrophage infection as well as virulence in a zebrafish infection model. Moreover, this mutant is incapable of aggregation and fails to express surface flagella or exhibit swarming motility. An evaluation of double csp gene deletion mutant (ΔcspBD, ΔcspAD and ΔcspAB) strains that produce single csp genes showed that there is redundancy as well as functional differences among the three L. monocytogenes Csps in their contributions to virulence, cellular aggregation, flagella production, and swarming motility. Protein and mRNA expression analysis further showed impaired expression of key virulence and motility genes in the csp mutants. Our observations at protein and mRNA level suggest Csp-dependent expression regulation of these genes at transcriptional and post-transcriptional levels. In a mutant lacking all csp genes (ΔcspABD) as well as those possessing single csp genes (ΔcspBD, ΔcspAD, and ΔcspAB) we detected reduced levels of proteins or activity as well as transcripts from the prfA, hly, mpl, and plcA genes suggesting a Csp-dependent transcriptional regulation of these genes. These csp mutants also had reduced or completely lacked ActA proteins and cell surface flagella but contained elevated actA and flaA mRNA levels compared to the parental wild type strain suggesting Csp involvement in post-transcriptional regulation of these genes. Overall, our results suggest that Csps contribute to the expression regulation of virulence and flagella-associated genes thereby promoting host pathogenicity, cell aggregation and flagella-based motility processes in L. monocytogenes.

Contribution of the cold shock protein CspA to virulence in Xanthomonas oryzae pv. oryzae

“…Bacterial Csps are highly conserved small multifunctional nucleic acid‐binding proteins that mediate a wide range of physiological functions, including stress resistance and virulence‐associated responses, by modulating transcription, translation and mRNA stability (Eshwar et al ., ; Schärer et al ., ). Csps have been identified as major determinants of pathogenicity in various disease‐causing bacteria, including Enterococcus faecalis , Staphylococcus aureus , Salmonella enterica , Brucella melitensis and Listeria monocytogenes (Eshwar et al ., ; Michaux et al ., , ; Sahukhal and Elasri, ; Wang et al ., ). Despite extensive research during the last decade, the molecular mechanism underlying the association of Csps and virulence has not been fully elucidated.…”

“…() and Eshwar et al . () reported that Csps regulate the production of the pore‐forming cytolysin listeriolysin, haemolysis phenotypes, cell aggregation and flagella‐based motility in Listeria monocytogenes . Wang et al .…”

Comparative Survival and the Cold-Induced Gene Expression of Pathogenic and Nonpathogenic Vibrio Parahaemolyticus from Tropical Eastern Oysters during Cold Storage

“…However, tdh from the clinical strain VP1 that was cultured in shrimp samples demonstrated a lower expression level at 9 • C, indicating that the gene expression at a low temperature was irregular among different strains and matrices [48]. Bacterial Csps are vastly conserved small multifunctional nucleic acid-binding proteins that mediate a wide range of physiological functions, including regulation of growth under both normal and cold conditions, stress resistance, and virulence-associated responses, by modulating transcription, translation, and mRNA stability [49]. Csps have been identified as major determinants of pathogenicity in several foodborne disease-causing bacteria, such as Listeria monocytogenes [49], Staphylococcus aureus [50], and Brucella melitensis [51].…”

“…Bacterial Csps are vastly conserved small multifunctional nucleic acid-binding proteins that mediate a wide range of physiological functions, including regulation of growth under both normal and cold conditions, stress resistance, and virulence-associated responses, by modulating transcription, translation, and mRNA stability [49]. Csps have been identified as major determinants of pathogenicity in several foodborne disease-causing bacteria, such as Listeria monocytogenes [49], Staphylococcus aureus [50], and Brucella melitensis [51]. Our study showed the V. parahemolyticus growth upon cold shock and the induction of cspA gene, which suggest, respectively, cellular adaptive mechanisms and an altered metabolic recovery.…”

One evolutionarily selected amino acid variation is sufficient to provide functional specificity in the cold shock protein paralogs of Staphylococcus aureus

“…Since mutagenesis experiments in E. coli , Yersinia enterocolitica and Salmonella show that one or more CSPs can be functionally compensated by the remaining non‐mutated homologs, it is thought that CSPs might have redundant roles. However, not all CSPs can totally restore the function of their mutated paralogs, suggesting a certain degree of specificity among them (Eshwar, Guldimann, Oevermann, & Tasara, ; Michaux et al, ; Neuhaus, Rapposch, Francis, & Scherer, ; Xia, Ke, & Inouye, ).…”