Development of a Biosensor for Rapid Identification of Campylobacter Jejuni in Poultry Products

Non-Technical Summary: Campylobacteriosis is one of the most common causes of diarrheal diseases in humans worldwide. The purpose of this study is to develop a portable biosensor based on the surface plasmon resonance platform for rapid detection (less than 1 hour) and identification of the foodborne pathogen Campylobacter jejuni in poultry carcass rinses.<P> Approach: The Alabama poultry industry produces around 19 million broilers per week. The state of Alabama has 11 broiler companies that employ 3,800 contract growers and a total of 80,000 people in the state. Development of a fast, sensitive, and selective analysis for monitoring foodborne pathogens associated with poultry products is of significance to the industry. A portable, analytical detection system will be valuable to the poultry industry in general as well as small businesses and grocery stores. In addition, by meeting the USDA goal of delivering safer foods by enhancing food safety techniques in Alabama, this synergistic project will improve our the chances of securing extramural funds from federal agencies to further expand this research program. This research will integrate antibody-based recognition of C. jejuni with a miniaturized SPR sensor transducer. Preliminary experiments in our laboratories have shown that immobilized, avidin-biotin conjugated antibodies have high specificity of interactions, and allowed for the detection of 100 to 1000 CFU of C. jejuni per ml of inoculated milk in only 25 minutes. Surface plasmon resonance is a powerful tool for biorecognition. SPR sensors are able to rapidly monitor any association or dissociation process in real time, without the need to label molecules and without the need for complex sample preparation. The sensors used in this work are dual channel SpreetaTM sensors produced by Texas Instruments (TI). The Spreeta sensor, a miniature (approximately 7g), fully integrated SPR device, consists of light emitting diode, polarizer, temperature sensor, 2 photodiode arrays, reflecting mirror, and optical plastic substrate. An AlGaAs light emitting diode with a wavelength of 830 nm is enclosed within an absorbing aperture box. LED emits light which illuminates the gold-coated thin glass with a wide range of angles after passing through a polarizer which selects the transverse magnetic polarized component. The light beam after multiple reflections with the gold coating of a slide and a mirror on the top of the sensor, reaches the photodiode array. The second part of the project will include the testing of DNA primers as capture mechanisms for the SPR sensor. DNA molecules are extremely resilient, and contrary to antibodies, DNA primers can withstand large variations in temperature without loosing their specificity. In addition, DNA molecules easily attach to different surfaces. Therefore, the attachment of DNA primers to the gold particles in the SPR system may be easily achieved.