Slide culture sensitivity tests.

A new method for slide culture sensitivity tests of Mycobacterium tuberculosis is described in which smear-positive sputum spread on slides is incubated without prior decontamination in a selective lysed human blood medium. Results are available 7 days after setting up the tests and are particularly useful for guiding the treatment of smear-positive patients with a long history of unsuccessful chemotherapy. Drug concentrations and definitions of resistance are suggested for tests against isoniazid, streptomycin, PAS, rifampicin ethambutol and ethionamide. A good correlation was seen between the results of these tests and those of standard indirect sensitivity tests.