Ping Xu, Ph.D.

Ping Xu, Ph.D.


Wood Memorial Building Link opens in new window
521 North 11th Street
Box 980566
Richmond, Virginia 23298-0566
Phone: (804) 827-6264
Fax: (804) 828-0150


  • Ph.D. in Molecular Biology, Oxford University, Nanjing University, 1989
  • M.S. in Biology, Nanjing University, 1986
  • B.S. in Biology, Nanjing University, 1982


We are studying oral microbial diseases by integrating advanced sciences including comparative genomics, proteomics, microarray and bioinformatics. Genes will be studied for their biological functions on a genome-wide scale and their interactions will be associated using systems biology approaches.

1. Regulation of Fitness and Virulence in Oral Streptococci

Based on the comparative genomics of S. sanguinis with other streptococci, we identified many transcriptional factors that regulate gene expression. We are studying their regulation and biological effects using microarray and sequencing technology.

2. Oral Microbiota

We are collaborating with clinical researchers to study the oral microbial community and the human microbiome. Microbial genome sequencing will be applied to study the biological diversity of uncultured microorganisms, or metagenomics. We are interested in studying medical microbial diversity in different biological niches.

3. Genetics in Oral Streptococcal Biofilm Formation

We have established an in vitro biofilm screening system for S. sanguinis. We are trying to identify genes affecting biofilm formation using a genome-wide deletion methodology. The association of biofilm genes will be studied using systems biology approaches. The oral microbiota and their association with oral diseases will also be studied.

4. Integrative Analysis of Streptococcal Virulence Genes

Efficient removal of invaded bacterial cells from the bloodstream is critical for control of infective streptococcal diseases. Recent developments in genomics, transcriptomics and proteomics present an opportunity to study streptococcal virulence as a whole using systems biology methods. We utilize bioinformatics tools and comprehensive immunological methods to identify virulence genes in oral streptococci. The virulence genes will be identified in blood assays. Gene interaction data will be obtained by bioinformatics. Critical genes will be identified by topological criteria and validated by their correlation with the experimentally found virulence genes. Furthermore, development of new vaccines against endocarditis by reverse vacccinology will be explored. We have active interactions with other faculty from different schools within VCU to identify virulence genes for drug target development.


Chen L, Ge X, Dou Y, Wang X, Patel JR, Xu P. Identification of hydrogen peroxide production-related genes in streptococcus sanguinis and their functional relationship with pyruvate oxidase. Microbiology. 2011;157:13-20
Kitten T, Turner LS, Xu P. Biological implications of the streptococcus sanguinis genome. In: Kolenbrander PE, ed. Oral microbial communities: Genomic inquiry and interspecies communication. Washington, D.C: ASM Press; 2011:43-61.
Manque PA, Probst CM, Pereira MC, Rampazzo RC, Ozaki LS, Pavoni DP, Silva Neto DT, Carvalho MR, Xu P, Serrano MG, Alves JM, Meirelles Mde N, Goldenberg S, Krieger MA, Buck GA. Trypanosoma cruzi infection induces a global host cell response in cardiomyocytes. Infect Immun. 2011;79:1855-1862 
Manque PA, Tenjo F, Woehlbier U, Lara AM, Serrano MG, Xu P, Alves JM, Smeltz RB, Conrad DH, Buck GA. Identification and immunological characterization of three potential vaccinogens against cryptosporidium species. Clin Vaccine Immunol. 2011;18:1796-1802
Rodriguez AM, Callahan JE, Fawcett P, Ge X, Xu P, Kitten T. Physiological and molecular characterization of genetic competence in streptococcus sanguinis. Mol Oral Microbiol. 2011;26:99-116
Xu P, Ge XC, Chen L, Wang XJ, Dou YT, Xu JZ, Patel JR, Stone V, Trinh M, Evans K, Kitten T, Bonchev D, Buck GA. Genome-wide essential gene identification in streptococcus sanguinis. Sci Rep-Uk. 2011;1
Das S, Kanamoto T, Ge X, Xu P, Unoki T, Munro CL, Kitten T. Contribution of lipoproteins and lipoprotein processing to endocarditis virulence in Streptococcus sanguinis. J Bacteriol. 2009 Apr 24

Ge X, Kitten T, Chen Z, Lee S, Munro CL and Xu P. Identification of Streptococcus sanguinis genes required for biofilm formation and examination of their role in endocarditis virulence. Infect & Immunity, 2008 Jun;76(6):2551-9.

Xu P, Alves JM, Kitten T, Brown A, Chen Z, Ozaki LS, Manque P, Ge X, Serrano MG, Puiu D, Hendricks S, Wang Y, Chaplin MD, Akan D, Paik S, Peterson DL, Macrina FL, Buck GA. Genome of the opportunistic pathogen Streptococcus sanguinis. J Bacteriol. 2007 Apr;189(8):3166-75.

Xu P, Alves JM, Kitten T, Brown A, Chen Z, Ozaki LS, Manque P, Ge X, Serrano MG, Puiu D, Hendricks S, Wang Y, Chaplin MD, Akan D, Paik S, Peterson DL, Macrina FL, Buck GA. Genome of the opportunistic pathogen Streptococcus sanguinis. J Bacteriol. 2007 Apr;189(8):3166-75.

Xu P, Widmer G, Wang Y, Ozaki LS, Alves JM, Serrano MG, Puiu D, Manque P, Akiyoshi D, Mackey AJ, Pearson WR, Dear PH, Bankier AT, Peterson DL, Abrahamsen MS, Kapur V, Tzipori S, Buck GA. The genome of Cryptosporidium hominis. Nature. 2004 Oct 28;431(7012):1107-12.

Abrahamsen MS, Templeton TJ, Enomoto S, Abrahante JE, Zhu G, Lancto CA, Deng M, Liu C, Widmer G, Tzipori S, Buck GA, Xu P, Bankier AT, Dear PH, Konfortov BA, Spriggs HF, Iyer L, Anantharaman V, Aravind L, Kapur V. Complete genome sequence of the apicomplexan, Cryptosporidium parvum. Science. 2004 Apr 16;304(5669):441-5.