Laboratory identification of mycobacteria in respiratory samples from HIV-positive patients suspected of tuberculosis.

The records (2000 to 2004) of the Microbiology Laboratory of the Adolfo Lutz Institute in Santos, Brazil, were retrospectively analyzed regarding patients infected with the human immunodeficiency virus (HIV) and suspected of pulmonary tuberculosis. 1,321 samples for diagnosis purposes were selected, corresponding to 880 suspected tuberculosis cases in 693 patients. There were 134 smear-positive samples and mycobacteria growth occurred in 188 cultures, corresponding to 161 confirmed cases. Mycobacterium tuberculosis was identified in 126 (78.3%) and non-tuberculous mycobacteria in 39 (24.2%). In four cases, both Mycobacterium tuberculosis and non-tuberculous mycobacteria were simultaneously recovered from different samples. The profile of sensitivity to anti-tuberculosis drugs revealed 18 (14.3%) cases of resistance to at least one drug. These results reinforce the need to carrying out the complete laboratorial routine (sputum smear microscopy, culture and susceptibility to antituberculous drugs) for respiratory samples from human immunodeficiency virus-positive patients with suspected tuberculosis in order to direct appropriate therapy.