The potential of the ESAT-6 antigen secreted by virulent mycobacteria for specific diagnosis of tuberculosis.
Tuberculosis (TB) remains a global health problem in humans and animals, and improved diagnostic methods are needed urgently. This study examined the potential of an interferon-gamma blood test based on a recently identified low-molecular-mass secreted protein antigen, ESAT-6, for early detection of bovine TB. It was found that field cases of bovine TB and experimentally infected cattle exhibited strong in vitro interferon-y responses directed toward this antigen. Of importance, ESAT-6 reactivity was found to discriminate between cattle infected with TB and cattle sensitized by environmental mycobacteria, and the gene encoding this molecule was demonstrated to be absent from >90% of the nontuberculous mycobacterial strains isolated from healthy sensitized cattle. These results demonstrate the feasibility of using single defined antigens for the highly specific diagnosis of TB.
Pollock
J M
JM
Department of Agriculture for Northern Ireland, Belfast, United Kingdom.
Andersen
P
P
D000818:Animals; D000942:Antigens, Bacterial / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics; D001500:BCG Vaccine; D001426:Bacterial Proteins; D002417:Cattle; D002418:Cattle Diseases; D003937:Diagnosis, Differential; D005798:Genes, Bacterial; D007114:Immunization / Q000662:veterinary; D007371:Interferon-gamma / Q000097:blood; D009162:Mycobacterium avium / Q000302:isolation & purification / Q000472:pathogenicity; D012680:Sensitivity and Specificity; D012882:Skin Tests; D014376:Tuberculosis / Q000175:diagnosis / Q000276:immunology / Q000662:veterinary*; D014774:Virulence
D000942:Antigens, Bacterial; D001500:BCG Vaccine; D001426:Bacterial Proteins; C093276:ESAT-6 protein, Mycobacterium tuberculosis; D007371:Interferon-gamma