Detection of rifampicin and isoniazid resistances of Mycobacterium tuberculosis strains by particle counting immunoassay (PACIA).

The particle agglutinated counting immunoassay (PACIA) was used to determine the susceptibility of Mycobacterium tuberculosis strains to the two major antimycobacterial drugs, isoniazid and rifampicin. On evaluating 12 M. tuberculosis strains with different sensitivities, our results were in complete accordance with those obtained using the well-known BACTEC system. The PACIA technique is automated and quite inexpensive. Interpretation of the test may be achieved in as little as five days.