Serodiagnosis of tuberculosis using an ELISA with antigen 5 and a hemagglutination assay with glycolipid antigens. Results in patients with newly diagnosed pulmonary tuberculosis ranging in extent of disease from minimal to extensive.

Hemagglutination tests with three glycolipid antigens, A1, B1, and C, and ELISA with antigen 5 were done on serum from Chinese patients with pulmonary tuberculosis and from normal subjects in Hong Kong. Tests with all four antigens were of similar efficiency, giving positive results in 30 to 52% of 88 smear-positive patients, in 16 to 22% of 37 smear-negative, culture-positive patients, in 5 to 13% of 76 culture-negative patients with radiologically active disease, in 5 to 11% of 217 culture-negative patients with inactive disease, and in 1 to 4% of 140 normal subjects. If tests were combined so that an overall positive was scored when all tests were positive, there was worse discrimination between patients and normal subjects; however, as suggested by the poor correlation between the results with pairs of the tests, better discrimination was obtained if an overall positive was scored when any of the tests was positive.

Resistance to rifampicin and isoniazid in strains of Mycobacterium tuberculosis.

Drug susceptibility studies on strains of Mycobacterium tuberculosis isolated from widely different populations of patients and tested by two different techniques indicated that all 55 strains resistant to rifampicin were also resistant to isoniazid, while many strains resistant to isoniazid were found to be susceptible to rifampicin. This observation, which has as yet unknown laboratory and clinical significance, may be particularly useful in management of patients. Further studies are called for to establish this relation.

Hemagglutination tests for tuberculosis with mycobacterial glycolipid antigens. Results in patients with active pulmonary tuberculosis before and during chemotherapy and in healthy tuberculosis contacts.

Hemagglutination tests using three serologically active mycobacterial glycolipids as antigens were carried out on serum specimens from patients with pulmonary tuberculosis and from healthy family contacts of patients with tuberculosis in Singapore. A positive response to any of the three antigens was found in 82.5% of 211 patients with newly diagnosed disease and in 21% of 100 contacts.

Comparison of enzyme-linked immunosorbent assay and hemagglutination test using mycobacterial glycolipids.

Enzyme-linked immunosorbent assay and hemagglutination methods were compared using mycobacterial glycolipids as antigens. Both methods were found to have equivalent specificity and sensitivity in detecting mycobacterial diseases. Both tests had 96% specificity; the sensitivity of the enzyme-linked immunosorbent assay was 86%, and that of the hemagglutination test was 88.

Rapid drug-susceptibility testing of Mycobacterium tuberculosis.

Three methods for rapidly determining the susceptibility of Mycobacterium Tuberculosis isolates to isoniazid, rifampin, ethambutol, streptomycin, and para-aminosalicylic acid were evaluated in a large-scale, blind study. Two of the methods measured evolution of CO2 from radio-labeled substrate (14CO2), and one method measured incorporation of 3H-uracil into ribonucleic acid. Rapid indirect drug-susceptibility test results for nearly 300 isolates were compared with those obtained using a standard modified proportion technique.