Bacteriophage-Mediated Toxin Gene Regulation in Clostridium difficile Export

@article{citeulike:5840022, abstract = {Clostridium difficile has been identified as the most important single identifiable cause of nosocomial antibiotic-associated diarrhea and colitis. Virulent strains of C. difficile produce two large protein toxins, toxin A and toxin B, which are involved in pathogenesis. In this study, we examined the effect of lysogeny by {Phi}CD119 on C. difficile toxin production. Transcriptional analysis demonstrated a decrease in the expression of pathogenicity locus (PaLoc) genes tcdA, tcdB, tcdR, tcdE, and tcdC in {Phi}CD119 lysogens. During this study we found that repR, a putative repressor gene of {Phi}CD119, was expressed in C. difficile lysogens and that its product, RepR, could downregulate tcdA::gusA and tcdR::gusA reporter fusions in Escherichia coli. We cloned and purified a recombinant RepR containing a C-terminal six-His tag and documented its binding to the upstream regions of tcdR in C. difficile PaLoc and in repR upstream region in {Phi}CD119 by gel shift assays. DNA footprinting experiments revealed similarities between the RepR binding sites in tcdR and repR upstream regions. These findings suggest that presence of a CD119-like temperate phage can influence toxin gene regulation in this nosocomially important pathogen. 10.1128/JVI.01256-09}, author = {Govind, Revathi and Vediyappan, Govindsamy and Rolfe, Rial D. and Dupuy, Bruno and Fralick, Joe A.}, citeulike-article-id = {5840022}, citeulike-linkout-0 = {http://dx.doi.org/10.1128/JVI.01256-09}, citeulike-linkout-1 = {http://jvi.asm.org/content/83/23/12037.abstract}, citeulike-linkout-2 = {http://jvi.asm.org/content/83/23/12037.full.pdf}, citeulike-linkout-3 = {http://view.ncbi.nlm.nih.gov/pubmed/19776116}, citeulike-linkout-4 = {http://www.hubmed.org/display.cgi?uids=19776116}, day = {1}, doi = {10.1128/JVI.01256-09}, issn = {1098-5514}, journal = {J. Virol.}, keywords = {bacteriophage-mediated, clostridium, difficile, gene, regulation, toxin, virulence}, month = {December}, number = {23}, pages = {12037--12045}, posted-at = {2009-11-05 17:13:59}, priority = {2}, title = {Bacteriophage-Mediated Toxin Gene Regulation in Clostridium difficile}, url = {http://dx.doi.org/10.1128/JVI.01256-09}, volume = {83}, year = {2009} }

TY - JOUR ID - citeulike:5840022 L3 - citeulike-article-id:5840022 N2 - Clostridium difficile has been identified as the most important single identifiable cause of nosocomial antibiotic-associated diarrhea and colitis. Virulent strains of C. difficile produce two large protein toxins, toxin A and toxin B, which are involved in pathogenesis. In this study, we examined the effect of lysogeny by {Phi}CD119 on C. difficile toxin production. Transcriptional analysis demonstrated a decrease in the expression of pathogenicity locus (PaLoc) genes tcdA, tcdB, tcdR, tcdE, and tcdC in {Phi}CD119 lysogens. During this study we found that repR, a putative repressor gene of {Phi}CD119, was expressed in C. difficile lysogens and that its product, RepR, could downregulate tcdA::gusA and tcdR::gusA reporter fusions in Escherichia coli. We cloned and purified a recombinant RepR containing a C-terminal six-His tag and documented its binding to the upstream regions of tcdR in C. difficile PaLoc and in repR upstream region in {Phi}CD119 by gel shift assays. DNA footprinting experiments revealed similarities between the RepR binding sites in tcdR and repR upstream regions. These findings suggest that presence of a CD119-like temperate phage can influence toxin gene regulation in this nosocomially important pathogen. 10.1128/JVI.01256-09 IS - 23 JF - J. Virol. SN - 1098-5514 EP - 12045 TI - Bacteriophage-Mediated Toxin Gene Regulation in Clostridium difficile VL - 83 SP - 12037 KW - bacteriophage-mediated KW - clostridium KW - difficile KW - gene KW - regulation KW - toxin KW - virulence AU - Govind, Revathi AU - Vediyappan, Govindsamy AU - Rolfe, Rial AU - Dupuy, Bruno AU - Fralick, Joe PY - 2009/12/01/ UR - http://dx.doi.org/10.1128/JVI.01256-09 ER -