Kunakorn M, Raksakait K, Sethaudom C, Sermswan R W, Dharakul T
Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
Acta Trop. 2000 Feb 5;74(2-3):247-51. doi: 10.1016/s0001-706x(99)00077-7.
Several sets of PCR primers have recently been developed for detection of Burkholderia pseudomallei. In this report, the performance of 16S rRNA gene primers (16S), rRNA spacer gene primers (spacer), and 'LPS' primers (LPS) were compared. All primer sets were tested by PCR amplification of the same DNA samples extracted from blood specimens of 46 patients from northeastern Thailand, of which 29 had melioidosis based on blood culture as a gold standard. The sensitivities were 41, 35.7, and 31% while the specificities were 47, 59, and 100% for the 16S, spacer, and LPS primers, respectively. The positive predictive values were 60, 59, and 100%, while negative predictive values were 35, 34, and 46%, for these primers. The low sensitivity of PCR was suspected to be because of small numbers of bacteria in the samples. In addition, one primer set could not detect all B. pseudomallei strains. To make PCR for melioidosis more practical, bacterial concentration steps must be added. Lastly, mixed infection of patients in endemic areas may be the cause of controversial false positive PCR results, and should be further investigated.
最近开发了几套用于检测类鼻疽伯克霍尔德菌的PCR引物。在本报告中，对16S rRNA基因引物（16S）、rRNA间隔基因引物（间隔区）和“LPS”引物（LPS）的性能进行了比较。所有引物组均通过对从泰国东北部46例患者血液标本中提取的相同DNA样本进行PCR扩增来测试，其中29例根据血培养作为金标准诊断为类鼻疽。16S、间隔区和LPS引物的敏感性分别为41%、35.7%和31%，特异性分别为47%、59%和100%。这些引物的阳性预测值分别为60%、59%和100%，阴性预测值分别为35%、34%和46%。PCR敏感性低被怀疑是因为样本中细菌数量少。此外，一组引物无法检测到所有类鼻疽伯克霍尔德菌菌株。为使类鼻疽的PCR检测更实用，必须增加细菌浓缩步骤。最后，流行地区患者的混合感染可能是PCR结果出现有争议的假阳性的原因，应进一步调查。
