Sero-prevalence and immunological characterization of Trypanosoma evansi infection in livestock of four agro-climatic Zones of Himachal Pradesh, India

Abstract

Trypanosoma evansi, a hemoflagellate protozoan parasite causes wasting disease called surra in wide range of animals. Although, the organism has been reported from various parts of the India, data generated from organized epidemiological study is still in infancy in majority states of India. In the present study, livestock of Himachal Pradesh, India was targeted for epidemiological investigation of T. evansi infections. A total of 440 equines and 444 cattle serum samples were collected from four agro-climatic Zones. Further, serum samples of 280 buffaloes from three different agro-climatic Zones of Himachal Pradesh were also collected and evaluated for presence of T. evansi infection by indirect ELISA. Data generated showed higher prevalence in buffalo (23.57%) followed by cattle (22.52%) and equines (1.82%). Disease was found to be more prevalent (P < 0.05) in cattle of lower altitude as compared to those of higher altitudes. No significant variation was seen in prevalence of disease on the basis of age and sex of the animals. Serum biochemical analysis revealed increased levels of BUN in T. evansi infected equines. Levels of liver function enzymes such as ALT/GGT and AST were found to be significantly elevated (P < 0.01) in infected animals whereas glucose levels were significantly lower in surra infected animals as compared to non-infected animals. Western blot analysis of whole cell lysate (WCL) antigen of T. evansi using surra infected serum samples of equines showed immunodominant bands in the range of 100-25 kDa. Surra infected bovine serum samples recognized polypeptide bands in the range of 85-32 kDa, including protein clusters of 52-55 and 48-46 kDa. Poypeptide cluster of 62-66 kDa was found common to serum samples of bovines and equines from all agro-climatic Zones. Animal trypanosomosis was found to be highly prevalent in livestock of Himachal Pradesh and thus there is dire need for designing of proper control strategies against surra.