Microbial Receptors Section, OIIB
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| Cross section of Actinomyces naeslundii showing the presence of cell surface fimbriae on this gram-positive oral microorganism |
NATIONAL INSTITUTES OF HEALTH/NIDCR
BUILDING 30 ROOM 301
30 CONVENT DR MSC 4350
BETHESDA MD 20892-4350
Phone: (301) 496-1822
Fax: (301) 402-1064
E-mail: john.cisar@mail.nih.gov
Research Interests
The etiologies of caries, gingivitis and periodontal disease are all closely associated with the development of dental plaque, the biofilm that forms from microbial colonization of the tooth surface. Initial colonization involves a limited number of gram-positive bacterial species, primarily viridans group streptococci and facultative actinomyces. These bacteria attach to host salivary components that coat the mineral surface and through growth and interactions between species form a relatively simple microbial community. Members of this community can activate host cells and the biofilm itself provides the habitat for additional species that are associated with the progression of dental caries and periodontal disease.
Research of the Microbial Receptors Section focuses on the structure, function and molecular biology of bacterial surface components that mediate microbial adhesion, colonization and the subsequent initiation of oral inflammation. Current studies focus on the genetic basis of streptococcal receptor polysaccharide structure, the pathway of fimbriae biogenesis in Actinomyces naeslundii and the molecular definition of early events in the pathogenesis of infective endocarditis.
Education
B.S. Colorado State University 1967
Ph.D. Oregon State University 1972
Recent publications
Xu, D. Q., Thompson, J. and Cisar, J. O. 2003. Genetic loci for coaggregation receptor polysaccharide biosynthesis in Streptococcus gordonii 38. J Bacteriol 185:5419-5430.
Takahashi, Y., Yajima, Y., Cisar, J. O., Konishi, K. 2004. Functional analysis of Hsa, the sialic acid-binding adhesin of Streptococcus gordonii DL1 and its essential role in bacterial binding to platelets. Infect. Immun. 72: 3876-3882.
Yoshida, Y., Ganguly, S., Bush, C. A, Cisar, J.O. 2005. Carbohydrate engineering of the recognition motifs in streptococcal coaggregation receptor polysaccharides. Mol. Microbiol. 58: 244-256.
Yoshida, Y., Ganguly, S., Bush, C.A., Cisar, J. O. 2006. Molecular basis of L-rhamnose branch formation in streptococcal coaggregation receptor polysaccharides of Streptococcus gordonii 38 and Streptococcus oralis 34. J. Bacteriol. 188: 4125-4130.
Lee, S.Y., Cisar, J.O., Bryant, J.L., Eckhaus, M.A., Sandberg, A.L. 2006. Resistance of Streptococcus gordonii to polymorphonuclear leukocyte killing is a potential virulence determinant of infective endocarditis. Infect. Immun. 74: 3148-3155.
Mishra, A., Das, A., Cisar, J. O., Ton-That, H. 2007. Sortase-catalyzed assembly of heteromeric fimbriae in Actinomyces naeslundii. J. Bacteriol. 189: 3156-3165.
Chen, P., Cisar, J.O., Hess, S., Ho, J, Leung, K.P. 2007. Amended description of the genes for synthesis of Actinomyces naeslundii T14V type 1 fimbriae. Infect. Immun. 75:4181-4185.
Yoshida, Y., Yang, J., Peaker, P.-E., Kato, H., Bush, C.A., Cisar, J.O. 2008. Molecular and antigenic characterization of a Streptococcus oralis coaggregation receptor polysaccharide by carbohydrate engineering in Streptococcus gordonii. J. Biol. Chem. (in press).