B.S., Pharmaceutical Sciences, Columbia University, New York, New York Ph.D., Biochemistry, University of Illinois, Chicago, Illinois Post-doctoral Research, National Institutes of Health, Bethesda, U.S.

The first is an investigation of factors secreted by certain pathogenic bacteria that can inhibit pathogen growth. These factors appear distinct from quorum sensors, which do not inhibit growth but switch on the expression of virulence genes when pathogens enter the stationary phase of growth in culture. Quorum sensors for Gram negative bacteria are derivatives of homoserine lactones, whereas quorum sensors for Gram positive bacteria are small peptides. Furthermore, these unknown factors also appear to be different from bacteriocins, which bacteria secrete and which prevent growth of competing organisms but not the bacterial species that secreted the factor. Our investigations center on the exact chemical structure for the inhibitory factors from both Gram negative and Gram positive organisms. Once the structures are known, we will investigate what regulates expression of these factors during growth, and how these factors might be used to treat patients with serious infections who are not responding well to antibiotics. The second area of interest is the application of a novel and highly sensitive biosensor that uses molecular interactions to identify pathogens and/or biological materials. This patented biosensor was developed in collaboration with faculty at the University of Maryland, College Park. The biosensor combines biotechnological principles with a fiber optic-based operating system that employs a near-infrared laser to create a positive fluorescent signal. After passage through a photoelectric tube that converts light impulses into electric ones, the pulses are then amplified by many magnitudes-of order. The electric signals are then detected and displayed on an oscilloscope. Current applications of this system include uses in medicine, agriculture, and biological warfare.