Detection of antibodies to a cocktail of mycobacterial excretory-secretory antigens in tuberculosis by ELISA and immunoblotting

摘要

The seroreactivity of a cocktail. of purified mycobacterial excretory-secretory (ES) antigens ES-31, ES-41 and ES43 was assessed by ELISA and immunoblotting in patients with pulmonary tuberculosis. The ES-31 antigen was isolated by affinity chromatography and ES-41 and ES-43 were isolated by fast protein liquid chromatography from Mycobacterium tuberculosis H37Ra culture filtrate. Seven-of 27 pulmonary tuberculosis sera Were not reactive to ES-31 antigen by ELISA. However, 6 out of 7 turned positive, when a cocktail of ES-31, ES-41 and ES-43 antigens was used in ELISA. Seroreactivity pattern of cocktail antigen was studied in immunoblotting; using tuberculous sera. Addition of ES-41 and ES-43 antigens helped in increasing the sensitivity compared to ES-31 alone. Further, ELISA was observed to be more sensitive than inummoblotting using a cocktail of antigens.