Poster
5 |
Comparison of conventional and Real-time PCR assays for diagnosis of Trypanosoma evansi infection |
This study was initiated to evaluate and compare two DNA based techniques (conventional and real-time PCR) for detection of Trypanosoma evansi. For this purpose, seventy three females’ mice were divided into two groups. In group I, 21 mice were inoculated by 104 trypanosomes; in group II, 42 mice were inoculated with 102 parasites and 5 mice were kept as non-infected control. The pre-patent periods were followed daily by the three assays. Results showed higher sensitivities of PCR and real time PCR using both TBR1/2 and TeRoTat1.2 primer sets than giemsa stained blood films in early determination of pre-patent periods as early as 24 hours post infection. Following up the course of infection by giemsa stained blood films revealed three waves of parasitemia alternated with three waves of non-detectable parasite in blood. The molecular techniques were able to clearly detect T. evansi in chronic stages of low parasitemia (periods of non-detectable parasites) throughout the course of infection. By testing field samples, real time PCR was more reliable in detecting and quantifying very low parasitemia in clinical camels’ blood samples than PCR. In conclusion, classical PCR with TBR is more sensitive than RoTat 1.2. RT-PCR with RoTat 1.2. is more sensitive than classical PCR with RoTat 1.2. RT-PCR with TBR and classical PCR with TBR have the same sensitivity. RT-PCR provides more convenient detection in field samples