Fluorogenic Cell-Based Biosensors for Microbial Monitoring

Great strides have been made in developing diagnostic systems for detecting and identifying specific pathogens and their toxins. However, these systems may be too specific and unable to detect newly emerging pathogens whose immunological or genetic profile is different than the normal complement of pathogens. The ideal system in an isolated environment such as a spacecraft would be one that provided a warning if any pathogen is present. In this Phase I effort, we propose to engineer chimeric proteins that fuse CD14 bacterial binding protein and the Fc portion of IgE antibodies. These novel bacterial receptors will bind to both mast cells and a large variety of pathogenic bacteria, enabling the mast cells to sense very low levels of contaminating bacteria from a diverse population. Using a compact yet highly sensitive fluorometer, this innovative biological receptor and signal transduction system will provide detection capability for a wide variety of pathogens in a single small and lightweight biosensor. This sensor will have applications in a number of testing regiments including being able to detect bacteria present in water, food, surfaces and the spacecraft air supply.