Glycolipid antigen for use in diagnostic assays for bovine tuberculosis.
A glycolipid antigen, was isolated, purified and characterized from Mycobacterium bovis An5. Chemical analysis (thin-layer chromatography, nuclear magnetic resonance and infrared spectra) showed that this glycolipid was a 2,3-di-O-acyl trehalose (DAT), similar to the DAT of M. tuberculosis. This antigen was used to establish ELISA-based serodiagnostic tests for M. bovis-infected cattle. The sensitivity and specificity of the assay were investigated using sera of cattle from tuberculosis-free herds and from tuberculosis-infected herds. No correlation was found between DAT-ELISA and the skin test, nor between DAT-ELISA and interferon-gamma with bovine purified protein derivative. The antibody titres were not related to cell-mediated immunity. Although the antigen was highly specific (95.9%), the sensitivity of DAT-ELISA, as judged from assays in bacteriologically confirmed tuberculosis, was low (29 to 36.8%). The low sensitivity of ELISA might also be attributed to a reciprocal relationship between B-cell proliferation and T-cell protective immunity.
CNEVA Alfort, Maisons-Alfort, France.
A
A
Ostyn
M A
MA
Lanéelle
M F
MF
Thorel
D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis; D000918:Antibody Specificity; D000942:Antigens, Bacterial / Q000302:isolation & purification*; D002417:Cattle; D002855:Chromatography, Thin Layer / Q000662:veterinary; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D006017:Glycolipids / Q000145:classification / Q000302:isolation & purification*; D007074:Immunoglobulin G / Q000276:immunology; D007371:Interferon-gamma / Q000032:analysis; D009682:Magnetic Resonance Spectroscopy; D009163:Mycobacterium bovis / Q000737:chemistry* / Q000276:immunology; D011817:Rabbits; D012680:Sensitivity and Specificity; D012882:Skin Tests / Q000662:veterinary; D013055:Spectrophotometry, Infrared / Q000662:veterinary; D014380:Tuberculosis, Bovine / Q000097:blood / Q000175:diagnosis* / Q000382:microbiology
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D006017:Glycolipids; D007074:Immunoglobulin G; D007371:Interferon-gamma