Santos Rose Mary Corrêa, Ogusku Mauricio Morishi, Miranda José de Moraes, Dos-Santos Maria Cristina, Salem Julia Ignez
Hospital Universitário Getúlio Vargas, Manaus, Amazonas, Brazil.
J Bras Pneumol. 2006 May-Jun;32(3):234-40.
To evaluate the accuracy of bacteriological methods and of polymerase chain reaction (with primers specific for IS6110 of the Mycobacterium tuberculosis complex) in testing sputum samples from indigenous (Amerindian) and non-indigenous patients.
A total of 214 sputum samples (154 from indigenous patients and 60 from non-indigenous patients) were analyzed in order to determine the accuracy of smear microscopy (direct and concentrated versions) for acid-fast bacilli, culture, and polymerase chain reaction.
Both microscopy methods presented low sensitivity in comparison with culture and polymerase chain reaction. Specificity ranged from 91% to 100%, the concentrated acid-fast smear technique being the least specific. Nontuberculous mycobacteria were isolated three times more frequently in samples from indigenous patients than in those from non-indigenous patients. False-positive and false-negative polymerase chain reaction results were more common in the indigenous population.
Positivity and isolation of nontuberculous mycobacteria in the acid-fast smear in conjunction with polymerase chain reaction positivity raise the following hypotheses: nontuberculous mycobacteria species with DNA regions homologous to, or even still possessing, the M. tuberculosis IS6110 exist in the Amazon; colonization of the oropharynx or of a tuberculous lesion accelerates the growth of the nontuberculous mycobacteria present in the sputum samples, making it impossible to isolate M. tuberculosis; A history of tuberculosis results in positivity for M. tuberculosis DNA. The absence of bacteriological positivity in the presence of polymerase chain reaction positivity raises questions regarding the inherent technical characteristics of the bacteriological methods or regarding patient history of tuberculosis.
评估细菌学方法及聚合酶链反应（使用针对结核分枝杆菌复合群IS6110的引物）检测本土（美洲印第安人）和非本土患者痰液样本的准确性。
共分析了214份痰液样本（154份来自本土患者，60份来自非本土患者），以确定抗酸杆菌涂片显微镜检查（直接涂片和浓缩涂片）、培养及聚合酶链反应的准确性。
与培养和聚合酶链反应相比，两种显微镜检查方法的敏感性均较低。特异性范围为91%至100%，浓缩抗酸涂片技术的特异性最低。在本土患者样本中分离出非结核分枝杆菌的频率是非本土患者样本的三倍。聚合酶链反应的假阳性和假阴性结果在本土人群中更为常见。
抗酸涂片中非结核分枝杆菌的阳性和分离以及聚合酶链反应阳性提出了以下假设：亚马逊地区存在与结核分枝杆菌IS6110具有同源DNA区域甚至仍拥有该区域的非结核分枝杆菌物种；口咽部或结核病灶的定植加速了痰液样本中存在的非结核分枝杆菌的生长，使得无法分离出结核分枝杆菌；结核病病史导致结核分枝杆菌DNA呈阳性。在聚合酶链反应阳性的情况下缺乏细菌学阳性结果，引发了关于细菌学方法的固有技术特征或患者结核病病史的问题。
