RESUMO
OBJETIVO: Comparar quatro métodos laboratoriais no diagnóstico de tuberculose pulmonar. MÉTODOS: Foram realizadas pesquisa direta pelas colorações de Ziehl-Neelsen e auramina, cultura para micobactérias em meio Lõwenstein-Jensen (LJ) e polymerase chain reaction (PCR, reação em cadeia da polimerase) para Mycobacterium tuberculosis em 160 amostras de secreção respiratória de pacientes com suspeita de tuberculose pulmonar. As cepas isoladas foram identificadas por método radiométrico utilizando-se p-nitro-alfa-acetilamino-beta-hidroxipropiofenona (NAP) e métodos clássicos. A sensibilidade dos métodos foi comparada com o padrão ouro para o diagnóstico da tuberculose pulmonar, definido por critérios clínicos, radiológicos e microbiológicos. RESULTADOS: Dos 160 pacientes, 142 foram diagnosticados com tuberculose pulmonar de acordo com o padrão ouro. As técnicas de Ziehl-Neelsen e auramina, cultura em meio LJ e PCR apresentaram sensibilidade de 54,2 por cento, 58,4 por cento, 67,6 por cento e 77,5 por cento, respectivamente, quando comparados ao critério diagnóstico adotado. A especificidade dos quatro métodos foi de 100 por cento. A concordância na identificação da micobactéria entre PCR e o método radiométrico utilizando NAP foi alta (96,8 por cento). A sensibilidade da PCR foi de 50,8 por cento nas amostras com baciloscopia negativa e de 98,8 por cento naquelas com baciloscopia positiva. Nas amostras com resultados negativos na baciloscopia e cultura, a sensibilidade da PCR foi menor que nas com resultados positivos (25,6 por cento e 99,0 por cento, respectivamente). CONCLUSÕES: A PCR é método promissor no diagnóstico da tuberculose pulmonar, mesmo em amostras paucibacilares. Além disso, apresenta a vantagem da identificação simultânea e rapidez do resultado.
OBJECTIVE: To compare four laboratory methods in the diagnosis of pulmonary tuberculosis. METHODS: Respiratory secretion specimens were collected from 160 patients suspected of having pulmonary tuberculosis. Direct testing for Mycobacterium tuberculosis was carried out using Ziehl-Neelsen and auramine staining. In addition, culture in Lõwenstein-Jensen (LJ) medium and polymerase chain reaction (PCR) were used. The strains isolated were identified by means of a radiometric method using p-nitro-alpha-acetylamino-beta-hydroxypropiophenone (NAP) and classical methods. The sensitivity of the methods was compared to the gold standard for the diagnosis of pulmonary tuberculosis, based on clinical, radiological and microbiological criteria. RESULTS: Of the 160 patients, 142 were diagnosed with pulmonary tuberculosis according to the gold standard. The sensitivity of Ziehl-Neelsen staining, auramine staining, culture in LJ medium and PCR was 54.2 percent, 58.4 percent, 67.6 percent and 77.5 percent, respectively, when compared with the diagnostic criterion adopted. All four methods presented 100 percent specificity. In the identification of mycobacteria, there was high (96.8 percent) concordance between PCR and the radiometric method using NAP. The sensitivity of PCR was 50.8 percent in samples with negative sputum smear microscopy results and 98.8 percent in those with positive results. The sensitivity of PCR was lower in specimens with negative results in sputum smear microscopy and culture than in those with positive results (25.6 percent and 99.0 percent, respectively). CONCLUSIONS: We found PCR to be a promising method for the diagnosis of pulmonary tuberculosis, even in paucibacillary specimens. Simultaneous identification and faster results are additional advantages of this method.
Assuntos
Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Técnicas Bacteriológicas/métodos , Mycobacterium tuberculosis/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Escarro/microbiologia , Coloração e Rotulagem/métodos , Tuberculose Pulmonar/diagnóstico , Benzofenoneídio , Corantes , Meios de Cultura , Interpretação Estatística de Dados , Hidroxipropiofenona/análogos & derivados , Hidroxipropiofenona , Mycobacterium tuberculosis/genética , Sensibilidade e Especificidade , Tuberculose Pulmonar/genética , Tuberculose Pulmonar/microbiologia , Adulto JovemRESUMO
OBJECTIVE: To compare four laboratory methods in the diagnosis of pulmonary tuberculosis. METHODS: Respiratory secretion specimens were collected from 160 patients suspected of having pulmonary tuberculosis. Direct testing for Mycobacterium tuberculosis was carried out using Ziehl-Neelsen and auramine staining. In addition, culture in Löwenstein-Jensen (LJ) medium and polymerase chain reaction (PCR) were used. The strains isolated were identified by means of a radiometric method using p-nitro-alpha-acetylamino-beta-hydroxypropiophenone (NAP) and classical methods. The sensitivity of the methods was compared to the gold standard for the diagnosis of pulmonary tuberculosis, based on clinical, radiological and microbiological criteria. RESULTS: Of the 160 patients, 142 were diagnosed with pulmonary tuberculosis according to the gold standard. The sensitivity of Ziehl-Neelsen staining, auramine staining, culture in LJ medium and PCR was 54.2%, 58.4%, 67.6% and 77.5%, respectively, when compared with the diagnostic criterion adopted. All four methods presented 100% specificity. In the identification of mycobacteria, there was high (96.8%) concordance between PCR and the radiometric method using NAP. The sensitivity of PCR was 50.8% in samples with negative sputum smear microscopy results and 98.8% in those with positive results. The sensitivity of PCR was lower in specimens with negative results in sputum smear microscopy and culture than in those with positive results (25.6% and 99.0%, respectively). CONCLUSIONS: We found PCR to be a promising method for the diagnosis of pulmonary tuberculosis, even in paucibacillary specimens. Simultaneous identification and faster results are additional advantages of this method.
Assuntos
Técnicas Bacteriológicas/métodos , Mycobacterium tuberculosis/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Escarro/microbiologia , Coloração e Rotulagem/métodos , Tuberculose Pulmonar/diagnóstico , Adulto , Idoso , Benzofenoneídio , Corantes , Meios de Cultura , Interpretação Estatística de Dados , Feminino , Humanos , Hidroxipropiofenona/análogos & derivados , Masculino , Pessoa de Meia-Idade , Mycobacterium tuberculosis/genética , Sensibilidade e Especificidade , Tuberculose Pulmonar/genética , Tuberculose Pulmonar/microbiologia , Adulto JovemRESUMO
We evaluated antimicrobial susceptibility patterns of microorganisms isolated from intraabdominal infection of Brazilian patients, by agar dilution, agar diffusion, and E test. Among the strictly anaerobes, 57.7% were resistant to penicillin, 28.2% to clindamycin, and 9.9% to metronidazole. The majority of Escherichia coli and Staphylococcus were sensitive and resistant to almost all drugs, respectively. Half of Candida samples were resistant to itraconazole. Our data reinforce the importance of this kind of study to support rational antimicrobial therapy.
