Résumé
Trypanosomosis or surra is caused by the haemoflagellate parasite, Trypanosoma evansi and is an important disease of animals, including domestic and wild herbivores and carnivores, in tropical countries. The invariant surface glycoproteins (ISGs) are blood stream stage specific and are uniformly distributed over the entire surface of the trypanosomes. In the present study, the extracellular domain (ED) region of ISG-75 from T. evansi, consisting of 1320 nt, encoding a polypeptide of 440 amino acids, has been heterologously expressed in Escherichia coli. Further, the immunoreactivity of recombinant ISG-75 (rISG-75) was characterized in immunoblot and ELISA using T. evansi hyper immune sera raised in experimental animals. The protein was found immunoreactive when compared with a panel of antigens (VSG RoTat 1.2 and whole cell lysate) using bovine serum samples from field. The diagnostic potential of rISG-75 was evaluated in ELISA with large number of bovine field serum samples. The optimum sensitivity and specificity were 98.47 and 99.1, respectively. The present finding showed that the expressed protein has potential use in the serodiagnosis of trypanosomosis.
Sujets)
Animaux , Séquence nucléotidique , Bovins , Maladies des bovins/diagnostic , Amorces ADN , Électrophorèse sur gel de polyacrylamide , Test ELISA/méthodes , Glycoprotéines membranaires/diagnostic , Réaction de polymérisation en chaîne , Protéines de protozoaire/diagnostic , Protéines recombinantes/diagnostic , Sensibilité et spécificité , Tests sérologiques/méthodes , Trypanosomiase/diagnostic , Trypanosomiase/médecine vétérinaireRésumé
Recently, it has been shown that immunological methods can be used for the diagnosis of malaria other than sero-epidemiology. A study has been done to investigate optimum binding capacity of antigen-antibody (Ag-Ab) at different serum dilutions. For validating antigen-antibody (Ag-Ab) reaction at 1:100, 1:1000 and 1:1000 serum dilutions, have been tested in two different laboratories to establish validation of the ELISA method. Inter laboratory test on synthetic peptide (RI) ELISA was found comparable and meaningful for assessing malaria transmission in defined locality at 1:100 dilution. Results also showed that 1:1000 serum dilution can be useful for diagnostic purpose.