Wolf Hilary, Mendez Melissa, Gilman Robert H, Sheen Patricia, Soto Giselle, Velarde Angie K, Zimic Mirko, Escombe A Roderick, Montenegro Sonia, Oberhelman Richard A, Evans Carlton A
Asociación Benéfica Prisma, Lima, Peru.
Am J Trop Med Hyg. 2008 Dec;79(6):893-8.
Pediatric pulmonary tuberculosis diagnosis is difficult because young children are unable to expectorate sputum samples. Testing stool for tuberculosis DNA from swallowed sputum may diagnose pulmonary tuberculosis. Hospitalized children with suspected tuberculosis had stool, nasopharyngeal, and gastric aspirates cultured that confirmed pulmonary tuberculosis in 16/236 patients. Twenty-eight stored stools from these 16 children were used to evaluate stool polymerase chain reaction (PCR) for tuberculosis diagnosis compared with 28 stool samples from 23 healthy control children. Two DNA extraction techniques were used: fast-DNA mechanical homogenization and Chelex-resin chemical extraction. DNA was tested for tuberculosis DNA with a hemi-nested IS6110 PCR. PCR after Fast-DNA processing was positive for 6/16 culture-proven tuberculosis patients versus 5/16 after Chelex extraction (sensitivity 38% and 31%, respectively). All controls were negative (specificity 100%). If sensitivity can be increased, stool PCR would be a rapid, non-invasive, and relatively bio-secure initial test for children with suspected pulmonary tuberculosis.
小儿肺结核的诊断较为困难，因为幼儿无法咳出痰液样本。检测粪便中来自咽下痰液的结核DNA或许能诊断肺结核。对疑似患有结核病的住院儿童的粪便、鼻咽部和胃吸出物进行培养，结果在236例患者中有16例确诊为肺结核。从这16名儿童中选取28份保存的粪便样本，与23名健康对照儿童的28份粪便样本一同用于评估粪便聚合酶链反应（PCR）对结核病的诊断效果。采用了两种DNA提取技术：快速DNA机械匀浆法和Chelex树脂化学提取法。运用半巢式IS6110 PCR检测DNA中的结核DNA。快速DNA处理后进行PCR检测，16例经培养证实为结核病的患者中有6例呈阳性，而Chelex提取后为5/16（敏感性分别为38%和31%）。所有对照均为阴性（特异性为100%）。如果能提高敏感性，粪便PCR将成为对疑似肺结核儿童进行快速、无创且相对生物安全的初始检测方法。
