Adaptation of an indirect enzyme-linked immunosorbent assay by purified gp51SU for detection of antibodies to bovine leukemia virus

The objective of this study was to compare an indirect ELISA, based on a purified 60 kDa envelope glycoprotein [gp51SU], with a Pourquire indirect ELISA for the detection of antibodies to the bovine leukemia virus. For conducting this research, 340 serum samples were collected from two different breeds of cows [Sarabi and Holestin] in different herds. Commercial ELISA revealed positive results in 17 [7%] Holstein cows. An appropriate ELISA cut-off was determined by receiver operating curve [ROC] analysis in comparison with commercial indirect ELISA. Results showed a relative sensitivity and specificity of 97% and 92%, respectively, for a cut-off value of 0.34 in the domestic ELISA. In conclusion, the results of the present study showed that domestic developed kit can be used for diagnosis of bovine leukemia virus with appropriate sensitivity and specificity. In addition, a comparison of the results from a native breed, Sarabi, with Holstein showed that there was no significant [P>0.05] difference in the frequency of infection with BLV between the two breeds

Study on pattern of Neospora caninum tachyzoite proteins by SDS-PAGE and Western blotting in aborted cows

The intracellular parasite Neospora caninum is prevalent in several countries and is increasingly recognized as an important cause of abortion and stillbirth in cattle. For characterizeing the tachyzoite antigens of Neospora caninum in aborted cows, sera were obtained from 116 cows which were aborted in the third semester of the pregnancy period and had antibodies to Neospora caninum in ELISA. To obtain the protein content of Neospora, purified tachyzoites were lysed, electrophoretically separated and blotted to nitrocelloluse membrane for immunostaining. Minimum 9 and maximum 13 protein bands ranging from 10 to 90 kDa were observed after immunostaining. It seems that, in almost all of the cows, two protein bands with a molecular weight of 45 and 41 kDa, have a prominent reaction in Western blotting. According to our findings, these two protein bands are the most important antigens observed after Western blotting, in seropositive aborted cows