Assessment and modification of a Western blot assay for detection of central nervous system tissue in meat products in the United States.
Health hazards associated with meat contaminated by the bovine spongiform encephalopathy agent have led to the development of tests for the presence of this agent. The objective of this study was to optimize a neuron-specific enolase Western blot assay for use in the United States. We compared the original test with a modified protocol to evaluate the detection limit for the presence of central nervous system (CNS) tissue in experimentally inoculated samples and compared and evaluated the utility of these tests for detecting CNS tissue in retail sausages. Sensitivity and specificity of the original and modified protocols were evaluated using the kappa statistic to assess agreement between the results of the two protocols. The original protocol resulted in 100% specificity and 92% sensitivity for raw samples and 92% specificity and 72% sensitivity for cooked samples. The modified protocol resulted in 92% specificity and 89% sensitivity for raw samples and 83% specificity and 75% sensitivity for cooked samples. The kappa statistic for protocol comparison was 0.94 for raw samples and 0.74 for cooked samples. Both protocols correctly identified CNS tissue in positive controls for each replicate. Although the Western blot technique should be considered for screening for the presence of bovine CNS tissue in meat samples, the techniques should be further optimized to address problems of low sensitivity. A test with higher sensitivity is needed to protect consumers from food safety threats associated with bovine CNS tissue.
Animal Population Health Institute, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado 80523, USA. m.d.salman@colostate.edu
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Salman
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Jemmi
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Triantis
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Dewell
D000818:Animals; D015153:Blotting, Western / Q000379:methods* / Q000592:standards; D002417:Cattle; D002645:Chickens; D003257:Consumer Product Safety; D016643:Encephalopathy, Bovine Spongiform / Q000517:prevention & control / Q000635:transmission; D005506:Food Contamination / Q000032:analysis*; D005511:Food Handling; D059022:Food Safety; D008461:Meat Products / Q000032:analysis*; D009417:Nerve Tissue; D012680:Sensitivity and Specificity; D013552:Swine; D014422:Turkeys; D014481:United States