Prevalence and molecular characterization of Trypanosoma evansi infections in dogs using RoTat 1.2 VSG gene from Punjab state, India.

The present study aims at development, standardization and application of Rode Trypanozoon antigenic type 1.2 variant surface glycoprotein (RoTat 1.2 VSG) gene based-PCR assay for the detection of Trypanosoma evansi in dogs of Punjab state, India. The prevalence rate was evaluated by screening 482 canine blood samples collected from various districts by microscopy and the standardized PCR assay. The T. evansi prevalence was estimated as 0.21 % (1/482) and 1.45 % (7/482) with microscopy and PCR assay, respectively. The comparative analysis of diagnostic sensitivity and specificity of PCR assay with microscopy revealed ″fair″ agreement by kappa value statistics between the two tests with a statistically significant (p<0.05) variation. Assessment of risk factors (age, breed, location, season and sex) associated with T. evansi infection, recorded a significant (p<0.05) correlation with age of host. The cladistics genetic diversity analysis of generated sequence data of RoTat 1.2 VSG gene exhibited 99.9-100.0 % homology among various T. evansi isolates of dogs. In the present study 03 sequences of RoTat 1.2 VSG gene from Punjab isolates were generated and used for the haplotype network analysis along with 16 T. evansi GenBank archived sequences. The sequences from India corresponding to different hosts revealed 09 haplotypes.