As additional information regarding cell-to-cell recognitions among oral bacteria is discovered, it is becoming increasing clear that a dynamic but organized microbial community exists in the oral cavity. The part of this complex community studied in this laboratory pertains especially to microbial ecology. Many of the bacteria that commonly inhabit this region were tested by an in vitro simulated plaque model. In the presence of potential competitors, several strains were tested as examples to support certain principles of coaggregation. Results of this study indicated that the oral cavity is replete with competitors and cohorts. Strains that belonged to different genera could recognize common third partners and prevented each other from coaggregating with them. Alternatively, demonstrations of multigeneric bacterial complexes were commonplace, indicating the similarity to associations of bacteria found in dental plaque. The surface structures that mediate these coaggregations were studied by using bacteriophage as surface probes and by isolating coaggregation-defective mutants. Identity of one receptor with a mediator of coaggregation was shown by altered coaggregation properties of bacteriophage-resistant mutants compared to their parent strains. To aid in further study of these surface structures, eight new actinomyces phage were isolated for the first time from human dental plaque. Studies with coaggregation-defective mutants revealed that certain outer membrane or surface proteins were altered or missing in the mutants but present in the parent strain. Results of a survey of the coaggregation properties of nearly 100 strains of Fusobacterium, Selenomonas, and Veillonella indicated that fusobacteria were very reactive, selenomonas hardly recognized any partners, and veillonella exhibited many lactose-inhibitable coaggregations. The results of each of these investigative approaches are focused on understanding the relationship of cell surface recognitions among oral bacteria and their role in microbial ecology.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Intramural Research (Z01)
Project #
1Z01DE000273-07
Application #
4692620
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
7
Fiscal Year
1985
Total Cost
Indirect Cost
Name
Dental & Craniofacial Research
Department
Type
DUNS #
City
State
Country
United States
Zip Code
Periasamy, Saravanan; Kolenbrander, Paul E (2009) Aggregatibacter actinomycetemcomitans builds mutualistic biofilm communities with Fusobacterium nucleatum and Veillonella species in saliva. Infect Immun 77:3542-51
Periasamy, Saravanan; Chalmers, Natalia I; Du-Thumm, Laurence et al. (2009) Fusobacterium nucleatum ATCC 10953 requires Actinomyces naeslundii ATCC 43146 for growth on saliva in a three-species community that includes Streptococcus oralis 34. Appl Environ Microbiol 75:3250-7
Jakubovics, Nicholas S; Gill, Steven R; Iobst, Stacey E et al. (2008) Regulation of gene expression in a mixed-genus community: stabilized arginine biosynthesis in Streptococcus gordonii by coaggregation with Actinomyces naeslundii. J Bacteriol 190:3646-57
Bachrach, Gilad; Altman, Hamutal; Kolenbrander, Paul E et al. (2008) Resistance of Porphyromonas gingivalis ATCC 33277 to direct killing by antimicrobial peptides is protease independent. Antimicrob Agents Chemother 52:638-42
Palmer Jr, Robert J; Diaz, Patricia I; Kolenbrander, Paul E (2006) Rapid succession within the Veillonella population of a developing human oral biofilm in situ. J Bacteriol 188:4117-24
Diaz, Patricia I; Chalmers, Natalia I; Rickard, Alexander H et al. (2006) Molecular characterization of subject-specific oral microflora during initial colonization of enamel. Appl Environ Microbiol 72:2837-48
Kolenbrander, Paul E; Palmer Jr, Robert J; Rickard, Alexander H et al. (2006) Bacterial interactions and successions during plaque development. Periodontol 2000 42:47-79
Rickard, Alexander H; Palmer Jr, Robert J; Blehert, David S et al. (2006) Autoinducer 2: a concentration-dependent signal for mutualistic bacterial biofilm growth. Mol Microbiol 60:1446-56
Diaz, Patricia I; Slakeski, Nada; Reynolds, Eric C et al. (2006) Role of oxyR in the oral anaerobe Porphyromonas gingivalis. J Bacteriol 188:2454-62
Yoshida, Yasuo; Palmer, Robert J; Yang, Jinghua et al. (2006) Streptococcal receptor polysaccharides: recognition molecules for oral biofilm formation. BMC Oral Health 6 Suppl 1:S12

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