Objective: To evaluate the performance of nested PCR (nPCR) in detecting the Mycobacterium tuberculosis complex in blood samples of patients suspected of having TB, in order to determine its potential for use as an auxiliary tool in the laboratory diagnosis of TB in children. Methods: Detection of the M. tuberculosis complex in blood samples using as a target the insertion sequence IS6110 of the genomic DNA of the bacillus. Blood samples of 120 patients were evaluated. All of the patients were under 15 years of age at the time of their treatment at public hospitals in the city of Recife, Brazil (between January of 2003 and August of 2005). Attending physicians at the hospitals diagnosed TB based on the criteria recommended by the American Thoracic Society. The nPCR amplified a 123-bp fragment with outer oligonucleotides (IS1/IS2) and, in the subsequent reaction, using inner oligonucleotides (IS3/IS4), generating an 81-bp amplicon. Results: Active or latent TB was found in 65 patients, TB was ruled out in 28 suspected cases, and 27 patients were TB-free (controls). The sensitivity of nPCR was 26.15% and was significantly higher for the extrapulmonary form of the disease (55.56%) than for the pulmonary form (18.18%). The specificity was 92.73%. Conclusions: Despite the difficulties in diagnosing TB in children and the low number of cases evaluated in the present study, nPCR in blood samples proved to be a rapid and specific technique, albeit one with low sensitivity. In order to establish its true usefulness in the diagnosis of paucibacillary forms, especially extrapulmonary TB, further studies need to be carried out with a larger sample of children and analyzing biological specimens other than blood.

Keywords: Tuberculosis; Diagnosis; Blood; Polymerase chain reaction.

Objective: To compare the performance of nested polymerase chain reaction (NPCR) with that of cultures in the detection of the Mycobacterium tuberculosis complex in pulmonary and extrapulmonary specimens. Methods: We analyzed 20 and 78 pulmonary and extrapulmonary specimens, respectively, of 67 hospitalized patients suspected of having tuberculosis. An automated microbial system was used for the identification of Mycobacterium spp. cultures, and M. tuberculosis IS6110 was used as the target sequence in the NPCR. The kappa statistic was used in order to assess the level of agreement among the results. Results: Among the 67 patients, 6 and 5, respectively, were diagnosed with pulmonary and extrapulmonary tuberculosis, and the NPCR was positive in all of the cases. Among the 98 clinical specimens, smear microscopy, culture, and NPCR were positive in 6.00%, 8.16%, and 13.26%, respectively. Comparing the results of NPCR with those of cultures (the gold standard), we found that NPCR had a sensitivity and specificity of 100% and 83%, respectively, in pulmonary specimens, compared with 83% and 96%, respectively, in extrapulmonary specimens, with good concordance between the tests (kappa, 0.50 and 0.6867, respectively). Conclusions: Although NPCR proved to be a very useful tool for the detection of M. tuberculosis complex, clinical, epidemiological, and other laboratory data should also be considered in the diagnosis and treatment of pulmonary and extrapulmonary tuberculosis.

Keywords: Tuberculosis/diagnosis; Tuberculosis/microbiology; Mycobacterium tuberculosis; Polymerase chain reaction.

Objective: Virulent strains of the Mycobacterium tuberculosis complex, under certain appropriate conditions, grow as characteristic ropes, bundles or serpentine cords known as cord factor or growth in cords. The objective of the present study was to evaluate cord factor detection as a method of achieving presumptive identification of the M. tuberculosis complex, comparing it to conventional typing tests. Methods: A total of 743 strains were analyzed from January of 2002 to December of 2005 in the Mycobacteria Sector of the Adolfo Lutz Institute, located in the city of Santos, Brazil. Samples were obtained from clinical specimens collected from patients with respiratory symptoms treated at basic health clinics in the greater metropolitan area of Santos. Ziehl-Neelsen-stained smears were prepared, 301 (40.5%) in MB/BacT broth and 442 (59.5%) on solid media, either Lowenstein-Jensen or Ogawa-Kudoh. Results: The sensitivity, specificity, positive predictive value and negative predictive value obtained during the performance comparison of the two methods (cord factor detection and conventional typing) using both isolation media were, respectively, 98.5, 88, 97 and 93%. The method was more sensitive on solid medium (100%), and the difference in sensitivity between the two media types was only 2.7%. Conclusions: Taking into consideration the results obtained, we conclude that, in laboratories with a high incidence of M. tuberculosis complex isolation and limited economic resources, cord factor detection is a fast and valid criterion for identifying these mycobacteria using liquid or solid medium. It also enables subsequent conclusive identification tests, as well as additional sensitivity tests when necessary.

Keywords: Laboratory techniques and procedures; Mycobacterium tuberculosis; Cord factors

In view of the fact that the World Health Organization has recommended the use of the mycobacteria growth indicator tube (MGIT) 960 system for the diagnosis of tuberculosis and that there is as yet no evidence regarding the clinical impact of its use in health care systems, we conducted a pragmatic clinical trial to evaluate the clinical performance and cost-effectiveness of the use of MGIT 960 at two health care facilities in the city of Rio de Janeiro, Brazil, where the incidence of tuberculosis is high. Here, we summarize the methodology and preliminary results of the trial. (ISRCTN.org Identifier: ISRCTN79888843 [http://isrctn.org/])

Keywords: Controlled clinical trial; Tuberculosis; Diagnostic tests, routine.

We compared the nitrate reductase assay with the proportion method, which is considered the gold standard, in 57 Mycobacterium tuberculosis strains isolated from patients treated at the Federal University of Minas Gerais Hospital das Clínicas, located in the city of Belo Horizonte, Brazil. For rifampin and isoniazid, the sensitivity, specificity, and accuracy of the nitrate reductase assay were all 100%, whereas they were 100%, 88.9%, and 66.7%, respectively, for streptomycin and 98.0%, 100%, and 98.2%, respectively, for ethambutol. The mean time to results was ten days. In the study sample, the nitrate reductase assay proved highly accurate and showed excellent concordance with the gold standard.

Keywords: Mycobacterium tuberculosis; Microbial sensitivity tests; Tuberculosis, multidrug-resistant; Nitrate reductase.

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.

Objective: To compare the accuracy of the amplified Mycobacterium tuberculosis direct (AMTD) test with reference methods for the laboratory diagnosis of tuberculosis in HIV-infected patients. Methods: This was a study of diagnostic accuracy comparing AMTD test results with those obtained by culture on Löwenstein-Jensen (LJ) medium and by the BACTEC Mycobacteria Growth Indicator Tube 960 (BACTEC MGIT 960) system in respiratory samples analyzed at the Bioassay and Bacteriology Laboratory of the Oswaldo Cruz Foundation Evandro Chagas Clinical Research Institute in the city of Rio de Janeiro, Brazil. Results: We analyzed respiratory samples collected from 118 patients, of whom 88 (74.4%) were male. The mean age was 36.6 ± 10.6 years. Using the AMTD test, the BACTEC MGIT 960 system, and LJ culture, we identified M. tuberculosis complex in 31.0%, 29.7%, and 27.1% of the samples, respectively. In comparison with LJ culture, the AMTD test had a sensitivity, specificity, positive predictive value, and negative predictive value of 87.5%, 89.4%, 75.7%, and 95.0%, respectively, for LJ culture, whereas, in comparison with the BACTEC MGIT 960 system, it showed values of 88.6%, 92.4%, 83.8%, and 94.8%, respectively. Conclusions: The AMTD test showed good sensitivity and specificity in the population studied, enabling the laboratory detection of M. tuberculosis complex in paucibacillary respiratory specimens.

Keywords: Molecular diagnostic techniques; Tuberculosis; HIV; Molecular probe techniques.

Objective: To describe the clinical manifestations of patients with pulmonary infection caused by mycobacteria of the Mycobacterium abscessus complex (MABSC), and to compare these manifestations with those of patients infected with other nontuberculous mycobacteria (NTM). Methods: This was a retrospective cohort study involving 43 patients divided into two groups: the MABSC group, consisting of patients with pulmonary infection caused by MABSC (n = 17); and the NTM group, consisting of patients with pulmonary infection caused by NTM other than MABSC (n = 26). Patients were previously treated with a regimen of rifampin, isoniazid, pyrazinamide, and ethambutol before the diagnosis of NTM was confirmed by two culture-positive sputum samples. The nucleotide sequences of the hsp65, 16S rRNA, and/or rpoB genes were analyzed to identify the mycobacteria. Data were collected on demographic, clinical, and radiological characteristics, as well as on treatment responses and outcomes. Results: Loss of appetite was the only clinical manifestation that was significantly more common in the MABSC group than in the NTM group (p = 0.0306). The chance of having to use a second treatment regimen was almost 12 times higher in the MABSC group than in the NTM group. Treatment success was significantly higher in the NTM group than in the MABSC group (83.2% vs. 17.6%; p < 0.0001). The chance of recurrence was approximately 37 times higher in the MABSC group than in the NTM group. Conclusions: In the study sample, treatment response of pulmonary disease caused by MABSC was less favorable than that of pulmonary disease caused by other NTM.

Keywords: Nontuberculous mycobacteria/classification; Nontuberculous mycobacteria/drug effects; Lung diseases.

Background: Various primers are being tested for the detection of Mycobacterium tuberculosis DNA. The accuracy of the polymerase chain reaction (PCR) depends on the target sequence used and whether the test will be performed in culture or in clinical specimens. Objectives: To identify DNA sequences, specifically those commonly reported as targets for diagnosis of tuberculosis (TB), in clinical samples of M. tuberculosis strains. Method: Eighty-one clinical samples from suspected TB patients were initially processed and submitted to bacilloscopy (smear) and culture, and PCR was performed with specific primers for the following targets: IS 6110, 65 kDa, 38 kDa and MPB64. Results: Smear and culture results were negative in 24 samples, as was the PCR. The 19 samples testing smear positive, as well as the isolated strains, were 100% positive on PCR, with the exception of the 89.4% result from PCR with MPB64 primers. In the 38 smear negative and culture positive samples, PCR results were inconsistent. The primers specific for amplifying the 123 bp IS 6110 fragment gave the highest positivity (92.1%), diagnostic agreement (0.9143), co-positivity (94.7%) and co-negativity (100%). Conclusion: The IS 6110, 38 kDa, MPB64 and 65 kDa sequences were found in the genome of all M. tuberculosis strains isolated in patients from the state of Amazonas. The protocol for processing the clinical samples prior to PCR analysis and the specific primers used to amplify the 123bp IS 6110 fragment showed a greater efficiency in diagnosing pulmonary (paucibacillary) tuberculosis in comparison to published data.

Keywords: Primers/PCR. Diagnosis/Tuberculosis. Mycobacterium tuberculosis.

Objective: To evaluate the accuracy of determining specific IgA to HspX recombinant antigen in pleural fluid and serum samples for the diagnosis of pleural tuberculosis in patients with pleural effusion. Methods: This was a cross-sectional study. Serum and pleural fluid samples of patients with pleural effusion and suspected of having pleural tuberculosis were tested with indirect ELISA in order to determine the optical density of specific IgA to HspX. Results: We evaluated serum and pleural fluid samples from 132 patients: 97 diagnosed with pleural tuberculosis (study group) and 35 diagnosed with pleural effusion due to other causes (control group). The determination of IgA in pleural fluid satisfactorily discriminated between pleural tuberculosis patients and control patients. The sensitivity of the test in pleural fluid and in serum was 69% and 30%, respectively, whereas the specificity was 83% and 84%, respectively. Conclusions: Our data suggest that this test can be used in the diagnosis of pleural tuberculosis. Further studies, involving larger patient samples and different epidemiological scenarios, are warranted.

Keywords: Pleural effusion; Tuberculosis/diagnosis; Enzyme-linked immunosorbent assay.

Background: The appearance of tuberculosis/human immunodeficiency virus co-infection and the growing number of diseases caused by nontuberculous mycobacteria, as well as the confusion that these can cause in relation to emerging multidrug-resistant strains, require more accurate and rapid laboratory results, not only in the isolation of strains but also in their identification. Objective: A comparative study evaluating a new tool of molecular identification, which uses a genetic probe based on the 16S rDNA sequence of the Mycobacterium tuberculosis gene (Gen-Probe Accuprobe® Gen Probe, Inc.), and the classic methodology. Method: Fifty-five Mycobacterium strains, isolated from the sputum of patients treated at a tuberculosis reference clinic, were selected for study. Subcultures were performed in three tubes: one submitted to genetic identification, one analyzed through classical tests (production and accumulation of niacin; growth in the Lowenstein-Jensen medium with the inhibitor agents p-nitrobenzoic acid and thiophene-2-carboxylic acid hydrazide added), and one held in reserve. Results: The probe identified 51 cases as belonging to the M. tuberculosis complex (one associated with M. kansasii) and the other 4 as nontuberculous mycobacteria, later identified as M. kansasii (3) and M. avium (1). Using traditional methods, 47 samples were identified as belonging to the M. tuberculosis complex, 4 were classified as fitting the profile of nontuberculous mycobacteria (in agreement with the genetic probe results), and 4 were unidentified, 1 of which presented the exact characteristics that 2 mycobacterium species have in common. Conclusion: The benefits of the molecular biology technique justify its implementation and routine use, in combination with classical methods, in a high-traffic clinic where complex cases of tuberculosis are treated.

Keywords: Mycobacterium tuberculosis. Molecular probe techniques.

Objective: To assess the diagnostic performance of the Xpert MTB/RIF assay, a rapid molecular test for tuberculosis, comparing it with that of AFB staining and culture, in BAL fluid (BALF) samples from patients with clinically suspected pulmonary tuberculosis (PTB) who are sputum smear-negative or produce sputum samples of insufficient quantity. Methods: This was a retrospective study of 140 cases of suspected PTB in patients who were smear-negative or produced insufficient sputum samples and were evaluated at a tertiary teaching hospital in the city of Rio de Janeiro, Brazil. All of the patients underwent fiberoptic bronchoscopy with BAL. The BALF specimens were evaluated by AFB staining, mycobacterial culture, and the Xpert MTB/RIF assay. Results: Among the 140 patients, results for all three microbiological examinations were available for 73 (52.1%), of whom 22 tested positive on culture, 17 tested positive on AFB staining, and 20 tested positive on the Xpert MTB/RIF assay. The sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy for AFB staining were 68.1%, 96.1%, 88.2%, 87.5%, and 87.6%, respectively, compared with 81.8%, 96.1%, 90.0%, 92.4%, and 91.8%, respectively, for the Xpert MTB/RIF assay. The agreement between AFB staining and culture was 82.3% (kappa = 0.46; p < 0.0001), whereas that between the Xpert MTB/RIF assay and culture was 91.8% (kappa = 0.8; p < 0.0001). Conclusions: In BALF samples, the Xpert MTB/RIF assay performs better than do traditional methods, providing a reliable alternative to sputum analysis in suspected cases of PTB. However, the rate of discordant results merits careful consideration.

Keywords: Tuberculosis; Molecular diagnostic techniques; Bronchoscopy; Bronchoalveolar lavage fluid; Mycobacterium tuberculosis.

Objective: To evaluate the results of thoracoscopy for the treatment of pleural empyema in pediatric patients. Methods: A retrospective study of 117 patients who underwent mediastinoscopy or video-assisted thoracoscopy for pleural empyema treatment. General anesthesia and single-lumen oral intubation were used. Surgery was indicated when there was pleural effusion and no clinical and radiological response to clinical treatment (antibiotics, physiotherapy and thoracocentesis) or severe sepsis, together with loculated pleural effusion (confirmed through ultrasound or computed tomography of the chest). Results: Between February of 1983 and July of 2006, 117 thoracoscopies were performed in patients ranging in age from 5 months to 17 years (mean, 4 years). Mean time for thoracic drainage was 9 days (range, 2-33 days), and mean period of hospitalization was 16.4 days (range, 4 to 49 days). One patient (0.8%) died after surgery, and persistent fistula was observed in 33 patients (28%). In 7 cases (6%), open thoracotomy with pulmonary decortication was performed due to the disposition of the empyema. Conclusions: Management of pleural empyema in this age bracket is still controversial, and surgical indication is often delayed, particularly when there are multiple loculations or severe sepsis. Early thoracoscopy yields a better clinical outcome for pediatric patients with pleural empyema, with apparent decreased morbidity and mortality, earlier chest tube removal, earlier hospital discharge and improved response to antibiotic therapy.

Keywords: Empyema, pleural; Pediatrics/instrumentation; Thoracoscopy; Thoracic surgery, video-assisted.

Objective: Nontuberculous mycobacteria (NTM) are a heterogeneous group of bacteria that are widely distributed in nature and associated with opportunistic infections in humans. The aims of this study were to identify NTM in patients with suspected tuberculosis who pre-sented positive cultures and to evaluate the genetic diversity of strains identified as Myco-bacterium avium. Methods: We studied pulmonary and extrapulmonary samples obtained from 1,248 patients. The samples that tested positive on culture and negative for the M. tu-berculosis complex by molecular identification techniques were evaluated by detection of the hsp65 and rpoB genes and sequencing of conserved fragments of these genes. All strains identified as M. avium were genotyped using the eight-locus mycobacterial interspersed repetitive unit-variable-number tandem-repeat method. Results: We found that NTM ac-counted for 25 (7.5%) of the 332 mycobacteria isolated. Of those 25, 18 (72%) were M. avium, 5 (20%) were M. abscessus, 1 (4%) was M. gastri, and 1 (4%) was M. kansasii. The 18 M. avium strains showed high diversity, only two strains being genetically related. Conclusions: These results highlight the need to consider the investigation of NTM in patients with suspected active tuberculosis who present with positive cultures, as well as to evaluate the genetic di-versity of M. avium strains.

Keywords: Mycobacterium avium; Nontuberculous mycobacteria; HIV; Genotyping techniques.

Objectives: To evaluate the contribution of Ultra to the diagnosis of pediatric pulmonary tuberculosis (PTB). Methods: We analyzed prospective data from children and adolescents with presumed PTB whose specimens were tested with Ultra between January 2020 and December 2022. Diagnosis was based on clinical-radiological criteria, clinical response after a two-month treatment period, and microbiological analysis. Ultra was considered positive with a result of 'Detected' and 'Traces' in children under 10 years and in HIV-infected individuals. Fisher's exact test was used for group comparisons, and McNemar's test was used to compare Ultra results with the diagnostic presumption. The study was approved by the Ethics Committee (CAAE No. 02173518.2.0000.5264). Results: A total of 41 patients were included, of whom 63% (26/41) were diagnosed with PTB. Among these, 9/26 (34%) had positive results only through Ultra, with negative AFB and culture. The sensitivity and specificity of Ultra were 50% (13/26) and 100% (15/15), respectively. The PPV was 100% (13/13), and the NPV was 54% (15/28). Of these 28 (68%) patients with negative Ultra results, 13 (46%) were diagnosed with PTB, mostly by MoH-SS. Considering culture as the reference, the PPV and NPV were 67% and 100%, respectively. Conclusions: Ultra significantly contributed to the diagnosis of pediatric PTB, proving to be a promising tool for paucibacillary forms of the disease. However, it should not be used alone. Integrating laboratory tests with clinical evaluation is essential to improving diagnostic accuracy and the management of pediatric TB.

Keywords: Pulmonary tuberculosis; children; adolescents; GeneXpert Ultra.

Objetivo: Verificar a detecção precoce de ototoxicidade causada pelo uso de amicacina numa população tratada para tuberculose multirresistente (TBMR) por meio da realização de três testes distintos: audiometria tonal liminar (ATL), audiometria de altas frequências (AAF) e pesquisa de emissões otoacústicas por produto de distorção (EOAPD). Métodos: Estudo longitudinal de coorte prospectiva incluindo pacientes de ambos os sexos, com idade entre 18 e 69 anos, com diagnóstico de TBMR pulmonar e que necessitaram utilizar amicacina por seis meses em seu esquema medicamentoso antituberculose pela primeira vez. A avaliação auditiva foi realizada antes do início do tratamento e depois de dois e seis meses do início do tratamento. A análise dos resultados foi realizada por meio de análise estatística sequencial. Resultados: Foram incluídos 61 pacientes, mas a população final foi constituída de 10 pacientes (7 homens e 3 mulheres), em razão da análise sequencial. Ao se comparar os valores das respostas dos testes com aqueles encontrados na avaliação basal, foram verificadas mudanças nos limiares auditivos compatíveis com ototoxicidade após dois meses de tratamento através da AAF e após seis meses de tratamento através da ATL. Entretanto, essas mudanças não foram verificadas através da pesquisa de EOAPD. Conclusões: Ao se considerar o método estatístico utilizado nessa população, é possível concluir que mudanças nos limiares auditivos foram associadas ao uso da amicacina no período de seis meses por meio de AAF e ATL e que a pesquisa de EOAPD não se mostrou eficiente na identificação dessas mudanças.

Keywords: Tuberculosis; Hearing loss; Aminoglycosides/toxicity.

Objective: To determine the drug resistance profile of Mycobacterium tuberculosis in the state of Mato Grosso do Sul, Brazil, between 2000 and 2006. Methods: Descriptive study of reported tuberculosis cases in the Brazilian Case Registry Database. We included only those cases in which M. tuberculosis culture was positive and sensitivity to drugs (rifampicin, isoniazid, streptomycin and ethambutol) was tested. Löwenstein-Jensen and Ogawa-Kudoh solid media were used for cultures, as was an automated liquid medium system. Sensitivity tests were based on the proportion method. Results: Among the 783 cases evaluated, males predominated (69.7%), as did patients in the 20-49 year age bracket (70%), a diagnosis of pulmonary tuberculosis (94.4%) and positive HIV serology (8.6%); 645 (82.4%) were new cases, and 138 (17.6%) had previously been treated. Resistance to at least one drug was found in 143 cases (18.3%). The primary resistance (PR) rate was, respectively, 8.1%, 1.6%, 2.8% and 12.4%, for monoresistance, multidrug resistance (MDR), other patterns of resistance and resistance to at least one drug, whereas the acquired resistance (AR) rate was 14.5%, 20.3%, 10.9% and 45.7%, respectively, and the combined resistance (CR) rate was 9.2%, 4.9%, 4.2% and 18.3%, respectively. In PR, streptomycin was the most common drug, whereas isoniazid was the most common in AR and CR (7.2% and 3.7%, respectively). Conclusions: These high levels of resistance undermine the efforts for tuberculosis control in Mato Grosso do Sul. Acquired MDR was 12.7 times more common than was primary MDR, demonstrating that the previous use of drug therapy is an indicator of resistance. These levels reflect the poor quality of the health care provided to these patients, showing the importance of using the directly observed treatment, short course strategy, as well as the need to perform cultures and sensitivity tests for the early diagnosis of drug resistance.

Keywords: Tuberculosis; Drug resistance, multiple; Mycobacterium tuberculosis.

Objective: To compare the prevalence rates of drug-resistant Mycobacterium tuberculosis in patients under intermittent treatment with those observed in patients under daily treatment. Methods: We used World Health Organization data regarding 5,138 patients with active pulmonary TB in Brazil, separated into two groups: patients in the Federal District of Brasília, treated with a one-month daily regimen followed by an intermittent thrice-weekly regimen; and patients in other parts of Brazil, treated with a daily regimen only. The resistance pattern was categorized as primary or acquired, based on the history of previous treatment. Multidrug resistance was defined as resistance to at least isoniazid and rifampin, whereas monoresistance was defined as resistance to only one drug. Results: The prevalence of primary resistance in the Federal District of Brasília and in the other parts of Brazil, respectively, was as follows: overall, 9.2% and 9.3% (p = 0.94); monoresistance, 6.6% and 6.9% (p = 0.89); and multidrug resistance, 1.0% and 1.2% (p = 0.85). The prevalence of acquired resistance in the Federal District of Brasília and in the other parts of Brazil, respectively, was as follows: overall, 15.8% and 26.8% (p = 0.39); monoresistance, 5.3% and 13.7% (p = 0.33); and multidrug resistance, 0.0% and 10.2% (p = 0.16). Conclusions: No significant differences were found between patients treated with an intermittent regimen and those treated with a daily regimen in term of resistance rates.

Keywords: Tuberculosis, pulmonary; Drug resistance; Drug administration schedule; Tuberculosis, multidrug-resistant.