USE OF THE POLYMERASE CHAIN-REACTION AND 16S RIBOSOMAL-RNA SEQUENCES FOR THE RAPID DETECTION OF BROCHOTHRIX SPP IN FOODS

Oligonucleotide primers were designed against rRNA sequences to give a DNA-based PCR assay for the rapid identification/detection of Brochothrix spp. The PCR products could be confirmed by hybridization to an internal oligonucleotide probe. The method successfully and sensitively detected/identified these organisms in pure cultures but was of limited value as a detection method because the detection sensitivity, in relation to conventional plate counts, varied and the assay sensitivity was reduced in the presence of staphylococci. Furthermore, sensitivity was also lost when the assay was applied directly to meat samples. However, a separation step using a lectin (from Agaricus bisporus) immobilized on magnetic beads prior to the PCR assay, allowed the direct detection of low numbers (> 10(2) cfu g-1) of Brochothrix in meat samples within a working day.