STUDIES ON THE RELIABILITY OF DIAGNOSIS O F ATYPICAL MYCOBACTERIAL INFECTION USING THE ELISA TECHNIQUE

Six groups of tuberculin-negative guinea-pigs were artificially infect ed with atypical mycobacterial strains, e.g. M. kansasii, M. scrofulac eum, M. intracellulare and M. fortuitum, and with two standard typical mycobacterial strains, i.e. M. bovis and M. avium. Serum samples were taken and a tuberculin test was carried out during the experiment. At the end of the experiment all the dead animals were subjected to post mortem examination and the strains used for inoculation were reisolat ed and identified. There were no tuberculin reactions in the infected groups of animals 2 weeks after infection (2 WPI). Animals infected wi th M. bovis and M. kansasii showed moderate tuberculin reactions with human PPD tuberculin. The Elisa technique was able to defect mycobacte rial antibodies early at 2 WPI, and a high titre was observed more fre quently in homologous reactions than in heterologous ones. The techniq ue could not, however, differentiate between infections involving diff erent mycobacterial strains. The ELISA test could thus be used as a sc reening test.