Kitten Lab Research

Currently Funded Research:

• (2001-2010) R01AI47841: Streptococcal virulence factors in extra-oral disease
• (2006-2011) C-VCU-07: Genetic competence in Streptococcus sanguinis

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. We are working to identify virulence factors required for Streptococcus sanguinis to cause endocarditis. Our approach has been to use the techniques of signature-tagged mutagenesis (STM) and in vitro transposition to create directed mutations in putative virulence genes encoding surface proteins in S. sanguinis, and then to test those mutants for virulence. We also recently completed the sequencing of the genome of S. sanguinis. Both the sequencing project and the STM project involve the same strain of S. sanguinis. 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. Finally, we are also examining the role of the competence genes of S. sanguinis on biofilm formation and virulence.

Recent Pulications:        Perform a PubMed search

Tang, G., Kitten, T., Munro, C. L., Wellman, G. C., and Mintz, K. P. (2008) EmaA, a potential virulence determinant of Aggregatibacter (Actinobacillus) actinomycetemcomitans in infective endocarditis. Infect Immun 76:2316-2324.

Ge, X., Kitten, T., Chen, Z., Lee, S. P., Munro, C. L., and Xu, P. (2008) Identification of Streptococcus sanguinis genes required for biofilm formation and examination of their role in endocarditis virulence. Infect Immun 76:2551-2559.

Xu, P., J. M. Alves, T. Kitten, A. Brown, Z. Chen, L. S. Ozaki, P. Manque, X. Ge, M. G. Serrano, D. Puiu, S. Hendricks, Y. Wang, M. D. Chaplin, D. Akan, S. Paik, D. L. Peterson, F. L. Macrina, and G. A. Buck. 2007. Genome of the opportunistic pathogen Streptococcus sanguinis. J Bacteriol 189:3166-3175.

Paik, S., Senty, L., Das, S., Noe, J. C., Munro, C. L., & Kitten, T. 2005. Identification of virulence determinants for endocarditis in Streptococcus sanguinis by signature-tagged mutagenesis. Infect Immun 73:6064-74.

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 63: 89-94.

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.

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.

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.

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.

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.

Training Opportunities:
Opportunities for research rotations often arise, dependent upon the availability of space and resources. The lab has accepted students from the following sources for rotations or graduate work:

• The Department of Microbiology and Immunology
• The Interdisciplinary Graduate Curriculum in Molecular Biology and Genetics
• The DDS Program
• The MD/PhD program
• The VCU Honors Program
• The VCU Bioinformatics and Bioengineering Summer Institute
• Other universities
• High schools