The modern mycobacteriology laboratory. How it can help the clinician

The mycobacteriology laboratory provides the information necessary to diagnose mycobacteriosis and to suggest proper patient management. When the definite diagnosis of disease due to M. tuberculosis is made on the basis of the laboratory result, contact follow-up studies should continue and the patient may be considered infectious if the bacilli were isolated from the sputum. A report of another Mycobacterium species suggests that a contact follow-up is not necessary, that the patient need not be isolated, and that a therapeutic regimen should be based on the results of drug-susceptibility tests with the isolate. Techniques of molecular biology are being used in the laboratory to provide the necessary information quickly for patient management. BACTEC has been accepted into most clinical laboratories to speed reporting of results. Other methods such as genetic and immunologic probes are under development. New DNA probes have been marketed by GenProbe for the identification of cultures of M. tuberculosis, M. avium, and M. intracellulare. HPLC and GLC have been used for the identification of cultures based on unique mycolic acid patterns of the species. Immunologic probes may eventually be the most specific and sensitive, but additional development is necessary. Mycobacteriophage typing of M. tuberculosis isolates has been developed as a tool to aid in epidemiologic studies. These and other technologies are essential in the support of programs for the elimination of tuberculosis.