Development of ELISA exploring recombinant variable surface glycoprotein for diagnosis of surra in animals.

In the present study, the variable surface glycoprotein (VSG) gene of Trypanosoma evansi was cloned and expressed in Pichia pastoris (X-33). The diagnostic potential of recombinant VSG (rVSG) in ELISA has been determined using 1818 field sera samples collected from different species across different states of India. The developed test was compared with the standard reference test such as, CATT/T. evansi; moreover, the new assay was also compared in ELISA using VSG RoTat 1.2 antigen. The diagnostic sensitivity and specificity of recombinant protein were found to be 95.4% and 93.8% respectively, with Cohen’s kappa value of 0.86. The epidemiological study revealed varied prevalence of surra in different species and across different geographical regions of India. Cattle experienced higher prevalence of surra with 42.2% seropositivity from eastern region of India, whereas camel showed 19.9% seropositivity from Rajasthan. Hence, the present study is useful as an effective tool in sero-diagnosis as well as surveillance. [ABSTRACT FROM AUTHOR]