Sensitivity and specificity of an ELISA as a screening test for the diagnosis of Brucella ovis in sheep.
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.
Departamento de Bacteriología, Centro Nacional de Investigaciones Disciplinarias en Microbiología, Cuajimalpa, México, D.F., México.
E D
ED
Núñez-Torres
E
E
Díaz-Aparicio
L
L
Hernández-Andrade
F J
FJ
Trigo-Tavera
F
F
Suárez-Güemes
D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood*; D002002:Brucella / Q000276:immunology*; D002006:Brucellosis / Q000175:diagnosis / Q000276:immunology / Q000662:veterinary*; D004797:Enzyme-Linked Immunosorbent Assay; D004823:Epididymitis / Q000175:diagnosis / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*; D008297:Male; D008403:Mass Screening / Q000662:veterinary*; D012680:Sensitivity and Specificity; D012756:Sheep; D012757:Sheep Diseases / Q000175:diagnosis* / Q000276:immunology
D000907:Antibodies, Bacterial