POOLING OF NONCOLLABORATIVE MULTILABORATORY DATA FOR EVALUATION OF THE USE OF DNA-PROBE TEST KITS IN IDENTIFYING LISTERIA-MONOCYTOGENES STRAINS

The Accuprobe test kit, a DNA probe culture confirmation test kit for identifying bacterial isolates as Listeria monocytogenes was evaluated with 148 food-borne Listeria isolates. The identities of the isolates were confirmed by conventional tests. A subset of the Listeria isolat es was also used to evaluate the Gene-Trak Listeria monocytogenes isol ation kit. The data obtained with each kit were pooled with data for t hat kit from independent published studies, Interlaboratory performanc es were then estimated statistically, to achieve the main features of orthodox interlaboratory collaborative studies. The large number of st rains required in this noncollaborative evaluation method advantageous ly provided a more representative sampling of the potential isolates t hat may be found in practice. Exact comparability between the two kit studies was not possible nor is it a feature of orthodox collaborative identification kit studies. However, the kits apparently performed eq uivalently given the different statistical confidences dictated by the study designs.