HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Supplementary data Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Karlsson, S. Articles by Åkerlund, T. Search for Related Content PubMed PubMed Citation Articles by Karlsson, S. Articles by Åkerlund, T. Agricola Articles by Karlsson, S. Articles by Åkerlund, T.

Induction of toxins in Clostridium difficile is associated with dramatic changes of its metabolism

¹ Swedish Institute for Infectious Disease Control, Department of Bacteriology, S-171 82 Solna, Sweden
² Karolinska Institute, Microbiology and Tumor Biology Center, S-171 77 Stockholm, Sweden

Correspondence
Thomas Åkerlund
Thomas.Akerlund{at}smi.se

Certain amino acids, and cysteine in particular, promptly blocked toxin expression in Clostridium difficile strain VPI 10463 when added to late-exponential-phase peptone-yeast cultures, i.e. prior to normal induction of toxins A and B. Glucose reduced toxin yields by 80-fold, but only when supplemented at inoculation. Forty upregulated C. difficile proteins were identified during maximum toxin expression, and most of these were enzymes involved in energy exchange, e.g. succinate, CO/folate and butyrate metabolism. Transcription of tcdA (toxin operon) and folD (CO/folate operon) was induced by 20- and 10-fold, respectively, and with strikingly similar kinetics between OD 0.8 and 1.2. The sigma factors tcdR and sigH were upregulated simultaneously with tcdA and folD (3.5-fold increase of mRNA level), whereas transcription of tcdC, codY, sigB and sigL showed little or no correlation with that of tcdA and folD. The results suggest a connection between toxin expression, alternative energy metabolism and initial sporulation events in C. difficile.

Two supplementary tables showing primers used for quantitative real-time PCR and identified proteins in C. difficile VPI 10463, and a supplementary figure showing a proteome map of C. difficile VPI 10463, are available with the online version of this paper.

This article has been cited by other articles:

				S. Underwood, S. Guan, V. Vijayasubhash, S. D. Baines, L. Graham, R. J. Lewis, M. H. Wilcox, and K. Stephenson Characterization of the Sporulation Initiation Pathway of Clostridium difficile and Its Role in Toxin Production J. Bacteriol., December 1, 2009; 191(23): 7296 - 7305. [Abstract] [Full Text] [PDF]

				R. Govind, G. Vediyappan, R. D. Rolfe, B. Dupuy, and J. A. Fralick Bacteriophage-Mediated Toxin Gene Regulation in Clostridium difficile J. Virol., December 1, 2009; 83(23): 12037 - 12045. [Abstract] [Full Text] [PDF]

				T. D. Lawley, N. J. Croucher, L. Yu, S. Clare, M. Sebaihia, D. Goulding, D. J. Pickard, J. Parkhill, J. Choudhary, and G. Dougan Proteomic and Genomic Characterization of Highly Infectious Clostridium difficile 630 Spores J. Bacteriol., September 1, 2009; 191(17): 5377 - 5386. [Abstract] [Full Text] [PDF]