Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: April 15, 2008
Publication Date: September 28, 2009
Citation: Tu, S., Uknalis, J., Gehring, A.G., Irwin, P.L. 2009. Pathogen detection in produce using applications of immunomagnetic beads and biosensors. In: Fan, X., Niemira, B.A.. Microbial Safety of Fresh Produce. Wiley-Blackwell: IFT Press. p. 331-348. Technical Abstract: The presence of pathogenic bacteria is of increasing public health concerns. Rapid and sensitive tests to detect pathogens are required to keep the safety of food supply. In this chapter we summarized our previous investigations where we applied immunomagnetic-bead (IMB) capture and various biosensors to detect pathogens in fresh produce. For cantaloupes two detection methods were presented, NAD(P)H driven chemilumenescence of viable cells and immuno sandwich method involving labeled antibody were developed. The NAD(P)H method detected E. coli O157:H7 at a level of 100,000 cells and antibody technique detected 10,000 cells. On alfalfa sprouts Salmonella & E. coli O157:H7 on sprouts and in irrigation water were captured by immunomagnetic beads and then detected by time-resolved fluorescence (TRF) method. TRF detected 1,000 cells of both species and was able to detect very low levels of pathogens in alfalfa seeds (~4CFU/g)after sprouting. The results demonstrated the efficacy of combing IMB capture and biosensors for the detection of pathogens in fresh produce.