Our research is focused on two important infectious diseases problems: 1. The molecular pathogenesis of leptospirosis, and; 2. Electrochemical detection of microbial pathogens. Click on the images above for more information.
Leptospirosis. The focus of our research is to elucidate the molecular mechanisms of pathogenesis and immunity mediated by outer membrane proteins (OMPs). Our laboratory has developed strategies for membrane fractionation and identification of surface-exposed OMPs. We identified a family of leptospiral immunoglobulin-like repeat (Lig) proteins that are targeted by the human immune response to leptospirosis. When virulent leptospires are exposed to host-physiologic levels of osmolarity, expression of LigA and LigB is dramatically increased. We found that the LigA and LigB bind host extracellular matrix proteins, indicating roles for Lig proteins in host tissue colonization. Recent studies indicate that the Lig proteins are extremely promising immunodiagnostic and vaccine antigens. Research supported by the National Institutes of Health (NIAID award R01 AI034431) and VA Medical Research Funds.
Electrochemical sensors for rapid bacterial pathogen identification and antibiotic susceptibility testing. Our electrochemical sensor assay was developed by a multidisciplinary team of scientists and involves "sandwich" hybridization of target 16S rRNA to species-specific capture and detector probes. Horseradish peroxidase coupled to the detector probe provides a redox signal that is reported as electrical current. The assay can be performed at room temperature, has the sensitivity to defect as few as 100 bacteria, and can be performed in less than 30 minutes. The sensor assay can identify and quantitate pathogens in clinical specimens, and also assess the susceptibility of pathogens to antibiotics. Rapid detection of drug-resistant bacterial pathogens would revolutionize the diagnosis and treatment of infectious diseases. Research supported by the National Institutes of Health (NIAID award U01 AI075565) and by the Wendy and Ken Ruby Fund for Excellence in Pediatric Urology Research.