Abstract β-Defensin-1, an antimicrobial peptide encoded by the DEFB1 gene, is known to play an important role in lung mucosal immunity. In our association study we analyzed three DEFB1 functional polymorphisms -52G>A (rs1799946), -44C>G (rs1800972) and -20G>A (rs11362) in 92 tuberculosis patients and 286 healthy controls, both from Northeast Brazil: no association was found between the studied DEFB1 polymorphisms and the disease. However we cannot exclude that this lack of association could be due to the low number of subjects analyzed, as suggested by the low statistical power achieved for the three analyzed SNPs (values between 0.16 and 0.50).

OBJETIVO: Comparar o desempenho da técnica nested polymerase chain reaction (NPCR) com aquele de culturas na detecção do complexo Mycobacterium tuberculosis em espécimes pulmonares e extrapulmonares.MÉTODOS: Analisamos 20 e 78 espécimes pulmonares e extrapulmonares, respectivamente, de 67 pacientes hospitalizados com suspeita de tuberculose. Um sistema automatizado foi utilizado na identificação de culturas de Mycobacterium spp., e M. tuberculosis IS6110 foi utilizada como sequência alvo na NPCR. A estatística kappa foi utilizada para verificar a concordância entre os resultados.RESULTADOS: Entre os 67 pacientes, 6 e 5, respectivamente foram diagnosticados com tuberculose pulmonar e extrapulmonar, e a NPCR foi positiva em todos os casos. Entre os 98 espécimes clínicos, a baciloscopia, cultura e NPCR foram positivas em 6,00%, 8,16% e 13,26%, respectivamente. Comparando-se os resultados da NPCR com aqueles da cultura (padrão ouro) nos espécimes pulmonares, a sensibilidade e a especificidade foram 100% e 83%, respectivamente, enquanto essas nos espécimes extrapulmonares foram 83% e 96% respectivamente, com boa concordância entre os testes (kappa, 0,50 e 0,6867, respectivamente).CONCLUSÕES: Embora a NPCR tenha se mostrado uma ferramenta muito útil na detecção do complexo M. tuberculosis, No entanto, os resultados positivos da NPCR devem ser associados à clínica, dados clínicos, epidemiológicos e outros dados laboratoriais devem também ser considerados no diagnóstico e tratamento da tuberculose pulmonar e extrapulmonar.

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.

Introduction This study evaluated the performance of an in-house nested-PCR system for the detection of the Mycobacterium tuberculosis complex in pleural fluid, blood and urine samples from pleural effusion tuberculosis patients by health services physicians in Pernambuco, Brazil. Methods A prospective double-blind study with 37 hospitalized patients of both sexes, aged over 15, was used to investigate the diagnosis of pleural effusion. The criteria used to define the cases included the demonstration of bacillus in biological samples by smear or culture or by a granulomatous finding in the histopathological examination, associated with an evident response to specific treatments to each clinical situation. Pleural fluid, blood and urine samples were collected and subjected to routine tests and the nested PCR technique to assess for M. tuberculosis amplification. Results In total, 37 pleural effusion patients took part in the study, of whom 19 (51.3%) had tubercular etiologies and 18 (48.7%) had etiologies from other causes. When the pleural fluid, blood and/or urine sample in-house nested-PCR sensitivities were evaluated simultaneously, the results were positive regardless of the biological specimen (the sensitivity was 84.2%); however, when the blood and/or urine samples were analyzed together, the sensitivity was 72.2%. When the pleural fluid samples were evaluated alone, the sensitivity was only 33.3%. Conclusions The performance of the diagnostic pleural tuberculosis nested-PCR was directly related to the diversity of the samples collected from the same patient. Additionally, this study may identify a need to prioritize non-invasive blood and urine collection for this diagnosis.

Introduction The early diagnosis of mycobacterial infections is a critical step for initiating treatment and curing the patient. Molecular analytical methods have led to considerable improvements in the speed and accuracy of mycobacteria detection. Methods The purpose of this study was to evaluate a multiplex polymerase chain reaction system using mycobacterial strains as an auxiliary tool in the differential diagnosis of tuberculosis and diseases caused by nontuberculous mycobacteria (NTM) Results Forty mycobacterial strains isolated from pulmonary and extrapulmonary origin specimens from 37 patients diagnosed with tuberculosis were processed. Using phenotypic and biochemical characteristics of the 40 mycobacteria isolated in LJ medium, 57.5% (n=23) were characterized as the Mycobacterium tuberculosis complex (MTBC) and 20% (n=8) as nontuberculous mycobacteria (NTM), with 22.5% (n=9) of the results being inconclusive. When the results of the phenotypic and biochemical tests in 30 strains of mycobacteria were compared with the results of the multiplex PCR, there was 100% concordance in the identification of the MTBC and NTM species, respectively. A total of 32.5% (n=13) of the samples in multiplex PCR exhibited a molecular pattern consistent with NTM, thus disagreeing with the final diagnosis from the attending physician. Conclusions Multiplex PCR can be used as a differential method for determining TB infections caused by NTM a valuable tool in reducing the time necessary to make clinical diagnoses and begin treatment. It is also useful for identifying species that were previously not identifiable using conventional biochemical and phenotypic techniques.

The authors report a case of a 12-year-old child with a complaint of pain and deformity in the lower thoracic region that had lasted for two years. Clinical, epidemiological and laboratory characteristics associated with images of apparent damage in the T9-T10 and T11-T12 vertebrae taken by radiography of the thoracic spine and nuclear magnetic resonance in addition to the positivity of the molecular test based on the polymerase chain reaction, led to tuberculous spondylitis being diagnosed and specific therapy was started. Culture of vertebral biopsy was positive for Mycobacterium tuberculosis after thirty days.