[Differentiation of M. tuberculosis and M. avium complex using various monoclonal antibodies]

M. avium-complex (MAC) is the cause of the most bacterial infections in AIDS patients. Because of the high resistance of MAC, a rapid differentiation between M. tuberculosis and MAC is of great interest. In an enzyme-linked immunosorbent assay (ELISA) we tested three monoclonal antibodies BS 103, BS 104, BS 113 and the combination of BS 103/BS 113, which bind selectively to the cell wall of M. tuberculosis. 98 MAC isolates from AIDS patients and 233 M. tuberculosis isolates from patients with lung disease were tested after primary culture of the bacteria on Lowenstein-Jensen media. ELISA could clearly discriminate MAC from M. tuberculosis with a specificity of 100% and a sensitivity of 98-100%. With these monoclonal antibodies the time for differentiation can be reduced by several weeks.