Assessment of Three Nucleic Acid Hybridization Systems for Detection of Campylobacter spp. in Poultry Products

Three commercially available nucleic acid hybridization systems were evaluated in combination with the United States Department of Agriculture-Food Safety and Inspection Service (USDA/FSIS) cultural protocol for the detection of Campylobacter spp. from a variety of poultry products. Samples were enriched for 24 h in Hunt broth and then plated onto modified charcoal Campylobacter differential agar. Suspensions of growth from the selective agar plates were then analyzed by the probe assays. The GENE-TRAK^® Campylobacter Assay (revised format) and the GEN-PROBE^® ACCUPROBE^™ Campylobacter Culture Confirmation Test showed sensitivities and specificities of 100% upon testing of 30 raw chicken rinses. The original format GENE-TRAK^® test had a sensitivity of 93% and a specificity of 100% when these samples were tested. Ninety percent of the raw chicken rinses were found to contain Campylobacter spp. By either of the two more sensitive probes or by the USDA/FSIS cultural method. Eighty-three percent of the rinses registered Campylobacter -positive by the original format GENE-TRAK^® probe. When inoculated ready-to-eat poultry samples were examined, the revised format GENE- TRAK^® test and the ACCUPROBE^™ assay had sensitivities of 83% and specificities of 100%. The original format GENE-TRAK^® test showed a 75% sensitivity and a 100% specificity with these samples. The USDA/FSIS cultural method had a sensitivity of 79% and a specificity of 100% with the inoculated samples. The detection limit of the revised format GENE-TRAK^® and the ACCUPROBE^™ assays upon testing pooled cell suspensions of four Campylobacter jejuni poultry isolates was approximately 10⁶ CPU/ml.