Flagellar antigen based CI-ELISA for sero-surveillance of surra

• Flagellar antigen and monoclonal antibody (MAb) based CI-ELISA was developed for detection of surra antibodies in animals.
• The test showed 95.8% sensitivity, 94.4% specificity and 0.83 Cohen’s kappa value when compared with standard test.
• The data suggested that the developed test has the potentiality to use in sero surveillance of ‘surra’ in animals.

Trypanosoma evansi causes a disease known as ‘surra’ in wide range of domesticated and wild animals including cattle, buffaloes, horses, camels etc. The disease is transmitted through the bites of haematophagous tabanid flies and is characterized by undulating fever, chronic progressive weakness, and hypoglycemia leading to low productivity in animals. In the present study, monoclonal antibodies (MAbs) have been produced (IgG3 sub-type) against purified flagellar (FLA) protein of T. evansi and its immunoreactivity was evaluated by serological tests. MAb and purified protein were then exploited in the development of CI-ELISA and the diagnostic potentiality of the new ELISA test has been evaluated using 1230 sera samples from field animals including cattle, buffaloes, camels, horses and donkeys. The statistical analysis of the data showed optimum combination of sensitivity and specificity at 95.8 and 94.4, respectively. The positive–negative cut off percentage inhibition (PI) value was found to be >55, with a Cohen’s Kappa value of 0.83. The study showed that the new assay has potential for application in sero-diagnosis as well as sero-surveillance of surra.

Flagellar (FLA) protein of T. evansi was isolated and purified and its related monoclonal antibody (MAbs) was produced. Later, FLA antigen and its related MAbs were used for the development of CI-ELISA. While comparing the developed test with CATT/T. evansi antigen from reference laboratory, it was found that the developed test is having sensitivity of 95.8% and specificity of 94.4%, to detect the antibodies against T. evansi in different species of animals. The Cohen’s kappa value was recorded as high of 0.83. The data from the present study suggested that the developed test has the potentiality to use in sero surveillance of surra in animals.Figure optionsDownload as PowerPoint slide