Comparative sensitivity of different primers in detection of Trypanosoma evansi infection in experimentally infected mice by Polymerase Chain Reaction vis-a-vis conventional Parasitological techniques

Sensitivity of four different sets of Trypanosoma evansi specific primers viz. ITS1/ CF/BR, ESAG 6/7, TBR1/2 and 21/22mer was evaluated by targeted amplification by polymerase chain reaction using different DNA extraction methods. PCR products obtained by using the ITS1/ CF/BR, ESAG 6/7, TBR1/2 and 21/22mer premiers yielded 480 bp, 237 bp, 164 bp multiples and 227 bp products, respectively. Overall results revealed TBR1/2 primers most sensitive followed by ESAG6/7 and 21/22-mer, where as ITS1 set of primers were least sensitive for detection of T. evansi DNA from infected mice blood and purified trypanosomes. Further PCR and parasitological diagnostic techniques viz. wet blood film (WBF), buffy coat (BC) and thin blood smear (TBS) were applied on blood samples collected from experimentally T. evansi infected mice at different intervals post infection for their comparative diagnostic evaluation. The results indicated PCR almost twice more sensitive as compared to CPT in terms of detection of T. evansi. PCR was able to detect the trypanosomes in pre patent phase.