This Article Full Text Full Text (PDF) Other Versions of this Article: AAC.01271-07v1 52/2/638    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Bachrach, G. Articles by Steinberg, D. Search for Related Content PubMed PubMed Citation Articles by Bachrach, G. Articles by Steinberg, D.

 Previous Article  |  Next Article 

Antimicrobial Agents and Chemotherapy, February 2008, p. 638-642, Vol. 52, No. 2
0066-4804/08/$08.00+0     doi:10.1128/AAC.01271-07
Copyright © 2008, American Society for Microbiology. All Rights Reserved.

Resistance of Porphyromonas gingivalis ATCC 33277 to Direct Killing by Antimicrobial Peptides Is Protease Independent

Institute of Dental Sciences, The Hebrew University-Hadassah School of Dental Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel,¹ National Institute of Dental and Craniofacial Research, National Institutes of Health, Building 30, Room 310, Bethesda, Maryland 20892,² Laboratory of Antimicrobial Peptides Investigation, Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology Haifa, Haifa, Israel,³ Department of Pharmaceutics, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel⁴

Received 1 October 2007/ Returned for modification 6 November 2007/ Accepted 3 December 2007

Antimicrobial peptides are short, positively charged, amphipathic peptides that possess a wide spectrum of antimicrobial activity and have an important role in the host's innate immunity. Lack of, or dysfunctions in, antimicrobial peptides have been correlated with infectious diseases, including periodontitis. Porphyromonas gingivalis, a gram-negative anaerobe and a major pathogen associated with periodontal diseases, is resistant to antimicrobial peptides of human and nonhuman origin, a feature that likely contributes to its virulence. Expressing a robust proteolytic activity, P. gingivalis hydrolyzes antimicrobial peptides. In this study, P. gingivalis inactivated three antimicrobial peptides, while a D-enantiomer was resistant to degradation. P. gingivalis was resistant to the protease-resistant D-enantiomer peptide, and importantly, a protease-deficient P. gingivalis mutant was also resistant to the antimicrobial peptide. Finally, the binding of a fluorescently labeled antimicrobial peptide to protease-deficient P. gingivalis was much weaker than the binding of susceptible Escherichia coli. Our results suggest that the resistance of P. gingivalis ATCC 33277 to direct killing by antimicrobial peptides is protease independent and results (at least partially) from the low affinity of antimicrobial peptides to P. gingivalis.

Published ahead of print on 17 December 2007.