半巢式聚合酶链反应扩增全血中梅毒螺旋体polA基因

目的探讨半巢式聚合酶链反应（PCR）扩增梅毒螺旋体（Tp）的DNA多聚酶Ⅰ基因（polA）以探讨检测全血标本中微量Tp的可行性。方法应用半巢式PCR和常规PCR分别扩增165例可疑梅毒及非梅毒患者全血中Tp的polA,与血清学方法比较,探讨半巢式PCR方法在扩增全血中Tp DNA的意义。结果待测的165例标本中,与血清学方法比较,半巢式PCR检测Tp的敏感性和特异性分别为62.7%和95.9%,两者符合率为82.4%;两种PCR方法检测结果差异有显著性（P〈0.01）,半巢式PCR敏感性远高于常规PCR。结论半巢式polA PCR检测全血中Tp较常规PCR灵敏,是血清学方法诊断梅毒的有效补充,但其检测的灵敏度仍有待进一步提高。

Amplification of the DNA Polymerase I Gene of Treponema Pallidum from Whole Blood of Persons With Syphilis Using a Semi-nested PCR Assay

Objective To investigate the contribution of a semi - nested polA PCR assay for the detection of extremely low numbers of treponema pallidum （Tp） in whole blood of persons with syphilis. Methods Routine PCR and semi - nested PCR assays were performed to amplify specific fragments of DNA polymerase Ⅰ gene （polA） of Tp from 165 whole - blood samples of persons with suspected syphilis or non -syphilis. Compared with serology, the semi -nested PCR method was evaluated in the detection of Tp in whole blood. Results Of 165 tests performed, directly compared with serology, semi -nested PCR showed 82.4% agreement, with a sensitivity of 62.7% and a specificity of 95.9%. There were significant differences between the two PCR assays in detection of Tp from whole blood and the semi - nested polA PCR was much more sensitive than the routine polA PCR （ P 〈 0.01 ）. Conclusions The semi - nestedpolA PCR assay is much more sensitive than the routine pelA PCR assay in detecting low numbers of Tp in whole blood samples as a useful addition to serology for the diagnosis of infectious syphilis. For the semi - nested polA PCR assay, the higher sensitivity for detection of Tp in whole blood should be enhanced.