Description of Research Expertise

Research Interests
- Bacterial pathogenesis
- Bacterial adhesion
- Salmonella and Escherichia coli fimbriae
- Salmonella and adhesin vaccines
- Yersinia pestis and pneumonic plague


Key words: Yersinia pestis, Salmonella, Escherichia coli, fimbriae, adhesion, plague.

Description of Research
The long-term goal of this laboratory is to understand how bacterial pathogens initiate their infectious process. Our research is directed towards bacterial ligands that bind to specific host receptors and mediate bacterial colonization, host cell signaling, and/or optimal toxin delivery. A better understanding of the structure and function of the microbial ligands and host receptors will help to design new prophylactic and therapeutic approaches against bacterial pathogens. Studies in this laboratory are focused on Yersinia pestis, Escherichia coli and Salmonella ligands. Although Yersinia pestis, the causative agent of Plague is best known to be transmitted by fleas to cause bubonic Plague, it can also be inhaled, triggering the more contagious and lethal pneumonic Plague. Aerosolized Y. pestis is feared as a most dangerous bioweapon, partly because there is currently no protective vaccine against pneumonic Plague. We are using information from the recently deciphered Y. pestis genome to determine whether putative adhesins and invasins effectively interact with respiratory tract epithelial cells or cells from the innate immune system. The immunogenic and protective properties of new adhesins and invasins that are expressed in infected hosts are being investigated for the development of a multi-subunit vaccine. Since aerosolized Y. pestis kills its hosts in 3-5 days, we are also interested in new virulence factors involved in subverting host innate immune response. Our current focus is on new mechanisms of bacterial resistance towards antimicrobial peptides.

The 987P-like CS18 fimbriae of human enterotoxigenic Escherichia coli ON phase variants. Fimbrial expression is regulated by CS18-specific DNA recombinases catalizing the inversion of a promoter-containing DNA segment. (Molecular Microbiology, Volume 48, Number 1, 2003, cover illustration)

Rotation Projects for 2009-2010
1. Cloning, expression and/or mutagenesis of Yersinia pestis genes for functional studies.
2. Competition or protection assays with murine models of plague.

Lab personnel:
Manoj Kumar Mohan Nair, Ph.D. - Postdoctoral Fellow
Min Yue, Ph.D. - Postdoctoral Fellow
Jitao Guo, Ph.D. Student (Peking University Student, China)