Flow cytometry for the detection of enterohaemorrhagic Escherichia coli O157 : H7 with latex beads sensitized with specific antibody

To detect low concentrations of enterohaemorrhagic Escherichia cell O157:H7 rapidly, flow cytometry (FCM) was carried out with specific IgG-sensitized latex beads (IgG-Lx). It was found that test samples for FCM can be prepar ed for much shorter periods by culturing E. coli O157:H7 in trypto-soya bro th at 42 degrees C and by treatment with 0.5 % formalin at 37 degrees C. FC M with IgG-Lx performed with a cell O157:H7 prepared by such a procedure re vealed that the lowest number of E. coli O157:H7 prepared in pure culture d etected by FCM was 10(3)/ml. Because similar findings have already been rep orted by FCM with immunomagnetic beads, FCM with IgG-Lx is also suggested t o be a valuable technique to detect low numbers of E. coli O157:H7 rapidly in food stuffs.