Serodiagnosis of environmental mycobacterial infections.

To demonstrate the usefulness of enzyme-linked immunosorbent assay for serodiagnosis of mycobacterioses due to environmental mycobacteria we utilized a panel of glycolipid antigens selective for Mycobacterium avium-intracellulare, Mycobacterium kansasii, Mycobacterium xenopi, Mycobacterium scrofulaceum and Mycobacterium gordonae. The levels of circulating antibodies were determined against the environmental mycobacteria, and Mycobacterium tuberculosis in human immunodeficiency virus-negative and -positive patient sera. The method used immunomagnetic separation of the antigens, with covalent immobilization of antibodies to superparamagnetic amine and carboxyl terminated particles in solutions of the specific antigens. Enzyme-linked immunosorbent assay was performed on 195 patient sera: 34 with infections due to environmental mycobacteria, 114 with tuberculosis, 47 with other respiratory diseases. There were 46 human immunodeficiency virus-1 infected individuals. Among the 34 infections due to environmental mycobacteria, 9 patients were singularly infected with an environmental mycobacterium, and 25 co-infected with both M. tuberculosis and an environmental mycobacterium. Sensitivity, specificity and false positivity ranges were determined for each of the volunteer groups: tuberculosis positive, human immunodeficiency virus negative; tuberculosis positive, human immunodeficiency virus positive; those with infections due to individual environmental mycobacteria (such as M. scrofulaceum and M. kansasii); and those with other respiratory diseases. We demonstrate that such multiple assays, can be useful for the early diagnosis of diverse environmental mycobacterial infections to allow the start of treatment earlier than henceforth.

Romanian anti-TB drugs resistance surveillance 2003-2004.

UNLABELLED: Romania decided and initiated a DRS for anti-TB drugs at national level using the standardized methodology proposed by WHO and IUATLD. The DRS protocol was designed with technical assistance from WHO; the surveillance started in June 2003 and ended in June 2004. It was tested the susceptibility to the 4 first line anti-TB drugs: Isoniazide (H), Rifampicin (R), Streptomycin (S), Ethambutol (E). Drug susceptibility testing used: indirect absolute concentration method. There were included in the survey 1251 TB patients from the 60 clusters: 869 new cases and 382 previously treated. From the penitentiary system were included 85 TB patients, 47 new cases and 38 previously treated. RESULTS: [table: see text]. Estimations of the trend of anti-TB drug resistance in Romania for the next period was proposed.

Rapid immunochromatographic serum assay of nontuberculous mycobacterial infections.

A rapid immunochromatographic serologic assay (Dot assay) is proposed to be applied on patients infected with nontuberculous mycobacteria (NTM). This assay could evidentiate the infecting species and allow the beginning of the treatment. The test is based on the principle of immunoblotting chromatography, a rapid membrane-based assay, capable of diagnosing NTM infections in serum, in less than 1 hour, with no need of special equipment or skilled staff. The secreted extracellular antigens have been isolated from the unheated culture filtrates of the clinically significant NTM (M. avium, MAI, M. kansasii, M. xenopi, M. chelonaei, M. scrofulaceum, M. marinum, M. fortuitum, M. abscesus, M. szulgai). The patients have been tested against these antigens, as well as from M. tuberculosis H37Rv, due to the possibility of co-infection with tuberculous bacilli. A number of 385 tests on patient sera have been performed (10, with NTM suspected infection, with or without M. tuberculosis co-infection, 5 with confirmed diagnosis of NTM infection, 10 with TB, 10 with other respiratory diseases). The preliminary results presented in this paper support the fact that the rapid immunochromatographic serum assay, combined with clinical and radiographic evidence, could evidentiate the infecting NTM species and allow the start of an earlier treatment, but must be confirmed on a higher number of patients.

Rapid dot sputum and serum assay in pulmonary tuberculosis.

A rapid direct sputum (Sp.) and/or antibody assay, based on immunoblotting and enzyme immunoassay is described. The test can detect mycobacterial antigens or antibodies in clinical specimens from pulmonary tuberculosis (TB) patients. In this study, 87 sputa, 87 sera and 40 paired sputa and sera were utilized from smear-positive and smear-negative, culture-positive patients; 59 sputa, 37 sera and 22 paired sputa and sera from nontuberculosis respiratory disease patients and 68 sera from healthy controls. The antigen detection in sputum by dot assay has 86.1% sensitivity on active tuberculosis patients, 92.9% specificity, 91.6% positive predictive value (PPV), 88.2% negative predictive value (NPV) and 10.3% error. The antibody assay has 83.6% sensitivity, 95.4% specificity, 94.4% positive predictive value, 85.6% negative predictive value and 11% error. The test performed on paired sputum and serum (Sr.) samples has a sensitivity of 93.3%, which rose to 96.1% on smear-positive and culture-positive patients, but the specificity decreased to 83% in sputum, whereas in serum it was 92%. The results of the assay, combined with clinical and radiological data, could form the basis for starting an earlier course of treatment for tuberculosis.