Submitted to: Research Workers in Animal Diseases Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 11/5/2001
Publication Date: 6/1/2001
Technical Abstract: A highly sensitive and specific method has been developed to reproducibly detect and quantitate Toxoplasma gondii burden in animal tissue samples using T. gondii ITS1-derived primers and a fluorogenic probe via real-time PCR. Assay specificity was confirmed against a panel of DNA samples from T. gondii and other common protozoa, as well as host animal tissue. This Toxo TaqMan assay was able to detect as little as 0.1 pg of T. gondii genomic DNA, and has a dynamic range of detection over 6-7 log of T. gondii DNA concentration. Tissues from T. gondii experimentally infected mice and pigs, as well as bradyzoite-spiked pig muscle samples, were used to test and standardize this technique. Positive signals were obtained with T. gondii parasite concentrations, ranging from 4 parasites to 105 parasites per gram of spiked pig tissue. All T. gondii-infected animals were correctly identified using this technique. Continuing work will be presented on using this assay to test swine carcasses and commercial pig products. Developments for faster processing of infected tissues will be presented. This assay will enable scientists to diagnose and quantitate T. gondii in animal tissues. Supported by NPPC #00-132 and National Pork Board #01-082 grants.