Philips Institute

Todd Kitten

Associate Professor of  of Oral &  Craniofacial Molecular Biology and Microbiology and Immunology  
Member Scientist, The Philips Institute


 

Education

• 1982-1986: BA Biology, The University of Dallas, Irving, TX and Rome, Italy  
• 1986-92: Ph.D. Microbiology, The University of Texas Health Science Center, San Antonio, TX

Professional Experience

• 1992-96 Postdoctoral fellow, Dept. of Plant Pathology, University of Wisconsin-Madison.
• 1996-97 Postdoctoral fellow, Dept. of Microbiology & Immunology, Virginia Commonwealth University
• 1997-98 Assistant Professor, Dept. of Microbiology & Immunology, Virginia Commonwealth University
• 1998-2004 Assistant Professor, Philips Institute of Oral and Craniofacial Molecular Biology, Virginia Commonwealth University
• 2004-present Associate Professor, Philips Institute of Oral and Craniofacial Molecular Biology, Virginia Commonwealth University

Honors

• 1990-1992: NIH Training Grant in Molecular Pathogenesis
• 1993-1996: NSF Postdoctoral Research Fellowship in Plant Biology
• 1997: Member, CDC Special Emphasis Panel on Lyme Disease
• 1998: Member, NIDCR Special Emphasis Panel on Genomic Sequencing of Streptococcus gordonii
• 2002: VCU School of Dentistry Research Award
• 2003:  President, Virginia Branch of the American Society for Microbiology
• 2003:  Special Reviewer, NIH Oral, Dental and Craniofacial Sciences (ODCS) Study

Funded Research

• 1K02AI05490: Streptococcal genomics and pathogenesis
• 1RO1AI47841: Streptococcal virulence factors in extra-oral disease

Research Interests

Research in the lab concerns virulence of oral streptococci in dental caries and in extra-oral diseases, especially endocarditis. The latter is characterized by infection of heart valves and subsequent impairment of function, and also frequently by serious complications such as heart attack and stroke. One focus of research is the characterization of an ABC-type metal uptake system in Streptococcus mutans. This system is required for S. mutans to cause endocarditis in an animal model and represents an attractive vaccine candidate. We are also working on identifying virulence factors required for Streptococcus sanguis to cause endocarditis. Our approach has been to adapt the technique of signature-tagged mutagenesis (STM) for use with S. sanguis. STM requires no prior assumptions concerning the importance of any particular gene or activity in disease causation. Instead, it relies on the infection process in an animal model to identify the bacterial genes needed for disease and their relative contributions. Our adaptation has involved the use of in vitro transposon mutagenesis for introducing tagged mutations into S. sanguis. We are currently in the process of creating, screening, and characterizing avirulent mutants of S. sanguis thus created. We are also involved in a project to sequence the genome of S. sanguis. Both the sequencing project and the STM project involve the same strain of S. sanguis. The two projects are complementary-the genome project provides sequence data for the STM project, while the STM project provides information concerning the function of genes identified by DNA sequencing.

Publications:

1. Paik, S., Senty, L., Das, S., Noe, J. C., Munro, C. L., & Kitten, T. (2005) Identification of virulence determinants for endocarditis in Streptococcus sanguis by signature-tagged mutagenesis. Infect. Immun.: in press.
2. Das, S., Noe, J. C., Paik, S., & Kitten, T. (2005) An improved arbitrary primed PCR method for rapid characterization of transposon insertion sites. J Microbiol Methods: in press.
3. Paik, S. Brown, A. Munro, C. L. Cornelissen, C. N. & Kitten, T. 2003. The sloABCR Operon of Streptococcus mutans Encodes a Mn and Fe Transport System Required for Endocarditis Virulence and its Mn-Dependent Repressor. J. Bacteriol. 185: 5967-5975.
4. Califano, J.V., Arimoto, T., & Kitten, T. 2003. The genetic relatedness of Porphyromonas gingivalis clinical and laboratory strains assessed by analysis of insertion sequence (IS) element distribution. J. Periodont. Res. 38: 411-416.
5. Kitten, T., Munro, C. L., Wang, A., & Macrina, F. L. 2002. Vaccination with FimA from Streptococcus parasanguis protects rats from endocarditis caused by other viridans streptococci. Infect. Immun. 70:422-425.
6. Kitten, T., Munro, C. L., Michalek, S. M., & Macrina, F. L. 2000. Genetic characterization of a Streptococcus mutans LraI family operon and role in virulence. Infect. Immun. 68:4441-4451.
7. Califano, J. V., Kitten, T., Lewis, J. P., Macrina, F. L., Fleischmann, R. D., Frasier, C. M., Duncan, M. J., & Dewhirst, F. E. 2000. Characterization of the Porphyromonas gingivalis Insertion Sequence-Like Element, ISPg5. Infect. Immun. 68:5247-5253.
8. Kitten, T., Kinscherf, T. G., McEvoy, J. L., & Willis, D. K. (1998) A newly-identified regulator is required for virulence and toxin production in Pseudomonas syringae. Mol. Microbiol. 28:917-930.
9. Kitten, T., & Willis, D. K. (1996) Suppression of a sensor kinase-dependent phenotype in Pseudomonas syringae by ribosomal proteins L35 and L20. J. Bacteriol. 178 :1548-1555.
10. Rich, J. J., Kinscherf, T. G., Kitten, T., & Willis, D. K. (1994) Genetic evidence that the gacA gene encodes the cognate response regulator for the lemA sensor in Pseudomonas syringae. J. Bacteriol. 176:7468-7475.
11. Willis, D. K., Rich, J. J., Kinscherf, T. G., & Kitten, T. (1994) Genetic regulation in plant pathogenic pseudomonads, in Genetic Engineering, eds. Setlow, J. T. (Plenum Press, New York), Vol. 16: 167-193.
12. Kitten, T., Barerra, A. V., & Barbour, A. G. (1993) Intragenic recombination and a chimeric outer membrane protein in the relapsing fever agent Borrelia hermsii. J. Bacteriol. 175:2516-2522.
13. Restrepo, B. I., Kitten, T., Carter, C. J., Infante, D., & Barbour, A. G. (1992) Subtelomeric expression regions of Borrelia hermsii linear plasmids are highly polymorphic. Mol. Microbiol. 6:3299-3311.
14. Kitten, T. & Barbour A. G. (1992) The relapsing fever agent Borrelia hermsii has multiple copies of its chromosome and linear plasmids. Genetics 132:311-324.
15. Barbour, A. G., Burman, N., Carter, C. J., Kitten, T. & Bergstrom, S. (1991). Variable antigen genes of the relapsing fever agent Borrelia hermsii are activated by promoter addition. Mol. Microbiol. 5:489-493.
16. Kitten, T. & Barbour, A. G. (1990) Juxtaposition of expressed variable antigen genes with a conserved telomere in the bacterium Borrelia hermsii. Proc. Natl. Acad. Sci. USA 87:6077-6081.

Lab Members

   Current:

• Todd Kitten  tkitten@vcu.edu
   BA in Biology, 1986, The University of Dallas, Irving, TX and Rome, Italy
   Ph.D. in Microbiology & Immunology, 1992, The University of Texas Health Science Center, San            
   Antonio, TX
• Nicai Zollar  zollarn@vcu.edu
  A.S., 2001 J. Sargent Reynolds Community College
• Taisei Kanamoto  kdaesung@vcu.edu
  D.D.S., 1988, Kyushu University School of Dentistry
  Ph.D., 1992, Kyushu University Graduate School
• Sankar Das  sdas@vcu.edu
  B.Sc. in Chemistry, 1983, University of Calcutta, India
  M.Sc. in Biochemistry, 1985, University of Calcutta, India
  Ph.D. in Biochemistry, 1996, University of Calcutta, India
• Lauren Senty  sentyla@mail1.vcu.edu
  B.S. in Biology, 2002, Virginia Tech

    Previous:   

• Jody Noe
  M.S., Molecular Biology and Genetics, 2003, Virginia Commonwealth University
  Currently: Chief, Disease Identification and Management Element, Lackland Air Force Base, San Antonio, TX
• Sehmi Paik  semi100@hotmail.com
  B.S., M.S., D.D.S., Seoul National University
  Ph.D. in Microbiology and Immunology, 2004, Virginia Commonwealth University
  Currently: Research Associate, Perinatology Research Branch, NICHD, NIH, Wayne State University, Detroit, MI

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Date last modified: 06/14/05