EXCEED THE SPACE PROVIDED. Streptococcus mutans is the major etiologic agent responsible for dental caries, the most prevalent disease in the developed as well as developing countries. Most clinical isolates of S. mutans produce antimicrobial peptides called mutacins. Mutacins are active against a wide spectrum of gram-positive bacteria including pathogens and oral commensals. Thus, mutacin production by S. mutans may play a double role: it provides the producing strain with a competitive edge in gaining dominance in the dental plaque, leading to dental caries. On the other hand, it may protect the human host from gram-positive bacterial infections. The proposed research aims to study the genetic, biochemical and biological aspects of mutacin biogenesis and regulation with the following approaches:
Aim 1, to characterize the trans-acting factors for mutacin gene regulation.
Aim2, to characterize the cis-acting factors that regulate mutacin gene expression.
Aim 3, to determine the structure/function of the mutacin molecule and improve mutacin's properties by genetic engineering.
Aim 4, to enhance mutacin biosynthesis and improve fermentation conditions. The proposed research will have a significant impact on two fronts. The first is the alarming surge in resistance to the existing battery of antibiotics by emerging and existing pathogens, and the increasing threat of bioterrorist attack using genetically engineered pathogens resistant to all existing antibiotics. These threats underpin the importance and urgency of finding unconventional antibiotics, to which resistance has not been developed. The second front is understanding the mechanism of gene regulation for mutacin production in S. mutans. This knowledge will help design effective control measures to curb the growth and virulence of S. mutans in the dental _laque. PERFORMANCE SITE ========================================Section End===========================================

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Research Project (R01)
Project #
5R01DE014757-03
Application #
6819734
Study Section
Oral Biology and Medicine Subcommittee 1 (OBM)
Program Officer
Shirazi, Yasaman
Project Start
2003-03-03
Project End
2007-11-30
Budget Start
2004-12-01
Budget End
2005-11-30
Support Year
3
Fiscal Year
2005
Total Cost
$304,406
Indirect Cost
Name
University of California Los Angeles
Department
Dentistry
Type
Schools of Dentistry
DUNS #
092530369
City
Los Angeles
State
CA
Country
United States
Zip Code
90095
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Okinaga, Toshinori; Niu, Guoqing; Xie, Zhoujie et al. (2010) The hdrRM operon of Streptococcus mutans encodes a novel regulatory system for coordinated competence development and bacteriocin production. J Bacteriol 192:1844-52
Kreth, Jens; Merritt, Justin; Qi, Fengxia (2009) Bacterial and host interactions of oral streptococci. DNA Cell Biol 28:397-403

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