Detection of Coxiella burnetii in cow's milk by PCR-enzyme-linked immunosorbent assay combined with a novel sample preparation method.

The use of an adequate concentration of Triton X-100 enhanced immunomagnetic separation of Coxiella burnetii from milk. PCR-enzyme-linked immunosorbent assay (PCR-ELISA) could detect coxiellas more sensitively than could conventional PCR. PCR-ELISA is therefore thought to be suitable for the simultaneous assay of a large number of samples. However, the number of cows from which raw milk tested positive for coxiellas by PCR-ELISA was inconsistent with that found with the antibody to coxiella by indirect immunofluorescence assay. The inconsistency is thought to be associated with the differences in the infectious route, infectious dose, or the timing of yielding the antibody and the period of duration of the antibody.