Subject(s)
Antigens, Bacterial , Brucella/isolation & purification , Brucellosis/veterinary , Sheep Diseases , Animals , Brucellosis/diagnosis , Drug Stability , Electrophoresis, Polyacrylamide Gel , Epididymitis/etiology , Epididymitis/microbiology , Epididymitis/veterinary , Immunodiffusion/methods , Male , Reproducibility of Results , Sensitivity and Specificity , Sepharose , Serologic Tests/methods , SheepABSTRACT
A hot saline extract of Brucella ovis strain REO 198 at a concentration of 5 micrograms/ml in phosphate buffer pH 7.2 was used to adsorb onto Maxisorb plates and incubated at 37 degrees C during 12 h; unadsorbed excess antigen was washed off thrice with phosphate buffer containing 0.5% Tween 20. As blocking agent 1% skim milk was used. The conjugate used was protein G bound to peroxidase diluted 1:100. Thirty three sheep sera from bacteriologically confirmed infected animals and 39 sheep sera from healthy animals from disease-free zones were used. Sera were diluted 1:200. ELISA's sensitivity was 97% and specificity 84%. The cut-off value was chosen for a high sensitivity (100%) despite some loss of specificity in order to diminish false negative results rendering thus a suitable screening test for sheep epididimitis caused by Brucella ovis.