Toxoplasma gondii detection

Bouchard, Emilie, Sharma, Rajnish, Bachand, Nicholas, Gajadhar, Alvin A. & Jenkins, Emily J., 2017, Pathology, clinical signs, and tissue distribution of Toxoplasma gondii in experimentally infected reindeer (Rangifer tarandus), International Journal for Parasitology: Parasites and Wildlife 6 (3), pp. 234-240 : 238

3.4. Toxoplasma gondii detection in tissues and organs

Following traditional (kit based) DNA extraction, T. gondii was detected by PCR in 3 — 8 tissues from each infected reindeer ( Table 2); heart was negative for all 3 reindeer and triceps was the only tissue that tested positive in all three reindeer. Following MC DNA extraction, DNA of T. gondii was detected in all tissue samples tested ( Table 2). Sequence analysis indicated 99% identity with T. gondii Type III VEG strain. For those tissues tested using both techniques (n = 26), the proportion of positive tissues among all tissues tested by traditional DNA extraction was 61.5% (16/26), and 100% (26/26) for MC. For traditional DNA extraction, positive controls of infected mice brain gave positive results, as well as the spiked beef sample for MC. Genotyping of MC positive samples (brain, heart, diaphragm) of each of the exposed reindeer were identified as T. gondii Type III VEG strain, the same strain given at inoculation.

No evidence of T. gondii was detected after serological and molecular testing of tissues from the unexposed control reindeer. The lack of personnel, time, material, and changes in the protocol after the euthanasia of the unexposed control reindeer explained the difference in number and quantity of samples collected and tested compared to the exposed ones.