Submitted to: Journal of Environmental Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/7/2009
Publication Date: N/A
Interpretive Summary: Tularemia, sometimes referred to as “rabbit fever”, is a life-threatening disease that is caused by the bacterium Fracisella tularensis. The bacterium that causes tularemia is extremely infectious and is considered by experts to have the potential for use as a biological weapon that could be directed to the food supply on an industrial scale. This is a serious concern of both the Department of Homeland Security (DHS) and the Food Safety and Inspection Service (FSIS) of the US Department of Agriculture. To be prepared to detect in a timely fashion food products contaminated with the tularemia bacterium is, therefore, imperative. Scientists with the Food Emergency Response Network (FERN) of the USDA Food Safety and Inspection Service in collaboration with a scientist from the USDA-ARS at J. Phil Campbell, Sr., Natural Resource Conservation Center, developed a rapid real-time polymerase chain reaction (PCR) method was developed to detect the tularemia bacterium in retail ground beef. This method was compared to a standard Food and Drug Administration (FDA) method based on growing the bacterium on a nutrient medium. Both methods were capable of detecting less than 100 tularemia bacteria per gram of ground beef. Whereas the FDA method took three days to obtain confirmed results, the real-time PCR method obtained confirmed results in less than eight hours. The time saved by this method of detection increases the potential of saving more lives were an act of bioterrorism to occur. This rapid method of detection will have application in FERN laboratories across the country, as well as in the international community, and further supports the Nation’s public health preparedness against bioterrorism.
Technical Abstract: Francisella tularensis, the etiologic agent of tularemia, is highly infectious and considered a critical biological agent for public health preparedness. Because of the potential of F. tularensis contaminating the food supply on an industrial scale, timely methods of detection must be in place. We compared a standard FDA culture-based method with a multi-targeted, real-time TaqMan PCR assay developed specifically for detecting small numbers of F. tularensis in environmental samples. Both the culture-based and real-time PCR methods were capable of detecting less than 100 F. tularensis cells g-1 of retail ground beef. The real-time PCR method yielded results in less than 6 h; whereas, the culture-based method yielded results in greater than 48 h. For detecting F. tularensis in ground beef, the real-time PCR protocol was timely and unequivocal in its detection.