Objective: To study the incidence of nontuberculous mycobacteria and the range of species isolated between 1996 and 2005 at a regional branch of the Adolfo Lutz Institute-located in the city of São José do Rio Preto, Brazil-and to show the importance of laboratory testing. Methods: Mycobacteria were isolated from pulmonary and extrapulmonary specimens and identified through phenotyping and molecular methods (polymerase chain reaction-restriction enzyme analysis). Results: We isolated 317 nontuberculous mycobacterium strains: ­Mycobacterium avium complex, 182 (57.4%); M. gordonae, 33 (10.4%); M. fortuitum, 25 (7.9%); M. chelonae, 8 (2.5%); M. terrae complex, 8 (2.5%); M. kansasii, 7 (2.2%); and less frequent species, 54 (17%). During this period, 72 cases (33.3%) were characterized as mycobacteriosis, according to bacteriological criteria established by the American Thoracic Society in 2007. Of those 72 cases, 56 were attributed to M. avium complex. Of those 56, 29 (51.8%) were characterized as disseminated disease. Six cases were attributed to M. fortuitum, 3 to M. gordonae, 2 to M. chelonae, 1 to M. abscessus, 1 to M. kansasii, 1 to M. intracellulare, 1 to M. malmoense and 1 to ­Mycobacterium ssp. Conclusions: These results show the importance of the bacteriological diagnosis, since identification of the species enables early and appropriate treatment.

Keywords: Mycobacteria, atypical/isolation & purification; Mycobacteria, atypical/classification; Diagnostic techniques and procedures.

Objective: The present study aims at describing the frequency of nontuberculous mycobacteria (NTM) species identified through laboratory testing of samples collected from non-sterile sites (sputum), as well as its frequency in HIV-infected and non-HIV-infected individuals in the Baixada Santista region of the state of São Paulo, Brazil, in the period from 2000 to 2005. Methods: Retrospective analysis of sputum smear microscopy results and culture was conducted based on the records on file at the Instituto Adolfo Lutz-Santos, the regional tuberculosis laboratory. Results: We analyzed 194 NTM strains isolated from 125 individuals, of whom 73 (58.4%) were HIV-negative and 52 (41.6%) were HIV-positive. Thirteen different species were identified: Mycobacterium kansasii; M. avium complex; M. fortuitum; M. peregrinum; M. gordonae; M. terrae; M. nonchromogenicum; M. intracellulare; M. flavescens; M. bohemicum; M. chelonae; M. shimoidei; and M. lentiflavum. In 19.2% of the cases, the bacteriological diagnosis was confirmed by isolation of the same species in at least two consecutive samples. Conclusions: Our results show the importance of including systematic identification of NTM in the laboratory routine, and that its integration into the clinical routine could improve the characterization of the disease, thereby informing the planning of effective control measures in specific populations, such as individuals presenting tuberculosis/HIV co-infection.

Keywords: Mycobacteria, atypical; Laboratory techniques and procedures; HIV; Tuberculosis.

Objective: The rapid differentiation between Mycobacterium tuberculosis and nontuberculous mycobacteria is fundamental for patients co-infected with tuberculosis and HIV. To that end, we use two methods in our laboratory: detection of cord factor and PCR-restriction enzyme analysis (PRA). The objective of this study was to evaluate the accuracy of a screening test on solid medium as a rapid method for the presumptive identification of M. tuberculosis complex, considering costs and turnover time. Methods: A total of 152 strains were submitted to a combined screening test, consisting of the detection of cord factor under microscopy (Ziehl-Neelsen staining) and evaluation of the macroscopic aspect of colonies, as well as to PRA, which was used as the gold standard. Costs were estimated by calculating the price of all of the materials needed for each test. Results: The overall accuracy of cord factor detection alone was 95.4% (95% CI: 90.7-98.1%), and that of the combined screening test was 99.3% (95% CI: 96.4-100%). Cord factor detection costs US$ 0.25, whereas the PRA costs US$ 7.00. Results from cord factor detection are ready in 2 days, whereas PRA requires 4 days to yield results. Conclusions: The presumptive identification of M. tuberculosis using the macroscopic evaluation of colonies combined with cord factor detection under microscopy is a simple, rapid and inexpensive test. We recommend the combined screening test to rapidly identify M. tuberculosis in resource-poor settings and in less well-equipped laboratories while awaiting a definite identification by molecular or biochemical methods.

Keywords: Tuberculosis; Mycobacterium/classification; Polymerase chain reaction; Diagnostic tests, routine.