This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Supplementary Material
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Google Scholar
Right arrow Articles by Ross, C. L.
Right arrow Articles by Koehler, T. M.
PubMed
Right arrow PubMed Citation
Right arrow Articles by Ross, C. L.
Right arrow Articles by Koehler, T. M.

 Previous Article  |  Next Article 

Journal of Bacteriology, November 2009, p. 6683-6693, Vol. 191, No. 21
0021-9193/09/$08.00+0     doi:10.1128/JB.00691-09
Copyright © 2009, American Society for Microbiology. All Rights Reserved.

An Extracytoplasmic Function Sigma Factor Controls β-Lactamase Gene Expression in Bacillus anthracis and Other Bacillus cereus Group Species{triangledown} ,{dagger}

Cana L. Ross, Kerrie S. Thomason, and Theresa M. Koehler*

Department of Microbiology and Molecular Genetics, The University of Texas-Houston Health Science Center Medical School, Houston, Texas 77030

Received 27 May 2009/ Accepted 11 August 2009

The susceptibility of most Bacillus anthracis strains to β-lactam antibiotics is intriguing considering that the closely related species Bacillus cereus and Bacillus thuringiensis typically produce β-lactamases and the B. anthracis genome harbors two β-lactamase genes, bla1 and bla2. We show that β-lactamase activity associated with B. anthracis is affected by two genes, sigP (BA2502) and rsiP (BA2503), predicted to encode an extracytoplasmic function sigma factor and an anti-sigma factor, respectively. Deletion of the sigP-rsiP locus abolished β-lactamase activity in a naturally occurring penicillin-resistant strain and had no effect on β-lactamase activity in a prototypical penicillin-susceptible strain. Complementation with sigP and rsiP from the penicillin-resistant strain, but not with sigP and rsiP from the penicillin-susceptible strain, conferred constitutive β-lactamase activity in both mutants. These results are attributed to a nucleotide deletion near the 5' end of rsiP in the penicillin-resistant strain that is predicted to result in a nonfunctional protein. B. cereus and B. thuringiensis sigP and rsiP homologues are required for inducible penicillin resistance in these species. Expression of the B. cereus or B. thuringiensis sigP and rsiP genes in a B. anthracis sigP-rsiP-null mutant confers inducible production of β-lactamase activity, suggesting that while B. anthracis contains the genes necessary for sensing β-lactam antibiotics, the B. anthracis sigP and rsiP gene products are not sufficient for bla induction.

* Corresponding author. Mailing address: Department of Microbiology and Molecular Genetics, University of Texas-Houston Medical School, 6431 Fannin St., MSB 2.106, Houston, TX 77030. Phone: (713) 500-5450. Fax: (713) 500-5499. E-mail: Theresa.M.Koehler{at}uth.tmc.edu

{triangledown} Published ahead of print on 28 August 2009.

{dagger} Supplemental material for this article may be found at http://jb.asm.org/.

Journal of Bacteriology, November 2009, p. 6683-6693, Vol. 191, No. 21
0021-9193/09/$08.00+0     doi:10.1128/JB.00691-09
Copyright © 2009, American Society for Microbiology. All Rights Reserved.





Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»