Leslie David E, Azzato Franca, Ryan Norbert, Fyfe Janet
Victorian Infectious Diseases Reference Laboratory, Melbourne Health Network, Carlton South, Victoria.
Commun Dis Intell Q Rep. 2003;27(3):373-9. doi: 10.33321/cdi.2003.27.64.
The Roche Cobas Amplicor Chlamydia trachomatis/Neisseria gonorrhoeae polymerase chain reaction (PCR) assay can simultaneously detect both C. trachomatis and N. gonorrhoeae, and has been cleared by United States Food and Drug Administration (FDA) for the testing of endocervical and urethral swabs and urine specimens. The Amplicor N. gonorrhoeae PCR target sequence is known to be present in some strains of commensal Neisseria species, including N. cinerea and N. subflava, necessitating the use of a second PCR assay to confirm positive results. This study analyses the performance of the assay on 7,007 unselected specimens submitted to the laboratory for the PCR diagnosis of N. gonorrhoeae and C. trachomatis; compares the PCR assay with culture for the detection of N. gonorrhoeae; examines the performance of the assay with specimens from different body sites; and briefly compares two confirmatory PCR assays. Confirmation rates for an initial Amplicor N. gonorrhoeae positive result varied widely by specimen type, ranging from 86.2 per cent for penile/urethral swabs to 5.6 per cent for oropharyngeal swabs, indicating all positive Amplicor N. gonorrhoeae results should be confirmed by a second method to maintain adequate specificity. Overall there was 98.1 per cent agreement between the confirmed PCR assay and culture, with confirmed PCR showing a sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 81.7 per cent, 99.5 per cent, 92.7 per cent and 98.5 per cent respectively, compared with N. gonorrhoeae culture. When confirmed C. trachomatis/N. gonorrhoeae PCR assay performance was analysed against culture using only FDA-cleared specimens (553 penile/ urethral swabs, urines and cervical/vaginal swabs), sensitivity, specificity, PPV and NPV and percent agreement were 96.7 per cent, 99.8 per cent, 98.9 per cent, 99.4 per cent and 99.3 per cent respectively. No significant differences were found between the two confirmatory PCR assays used during the study period. Limitations of Amplicor for the detection of N. gonorrhoeae and the appropriate use of combined C. trachomatis/N. gonorrhoeae PCR in a routine diagnostic setting are discussed.
罗氏Cobas Amplicor沙眼衣原体/淋病奈瑟菌聚合酶链反应（PCR）检测法可同时检测沙眼衣原体和淋病奈瑟菌，并且已获得美国食品药品监督管理局（FDA）批准，用于检测宫颈拭子、尿道拭子和尿液标本。已知淋病奈瑟菌PCR的靶序列存在于某些共生奈瑟菌属菌株中，包括灰色奈瑟菌和微黄奈瑟菌，因此需要使用第二种PCR检测法来确认阳性结果。本研究分析了该检测法对7007份未经筛选的标本（这些标本被送至实验室用于淋病奈瑟菌和沙眼衣原体的PCR诊断）的检测性能；将PCR检测法与淋病奈瑟菌培养法在检测淋病奈瑟菌方面进行了比较；研究了该检测法对来自不同身体部位标本的检测性能；并简要比较了两种确认性PCR检测法。初始Amplicor淋病奈瑟菌检测结果的确认率因标本类型而异，差异很大，从阴茎/尿道拭子的86.2%到口咽拭子的5.6%不等，这表明所有Amplicor淋病奈瑟菌阳性结果均应用第二种方法进行确认，以保持足够的特异性。总体而言，经确认的PCR检测法与培养法之间的一致性为98.1%，与淋病奈瑟菌培养法相比，经确认的PCR检测法的灵敏度、特异性、阳性预测值（PPV）和阴性预测值（NPV）分别为81.7%、99.5%、92.7%和98.5%。当仅使用FDA批准的标本（553份阴茎/尿道拭子、尿液以及宫颈/阴道拭子），针对培养法分析经确认的沙眼衣原体/淋病奈瑟菌PCR检测法的性能时，灵敏度、特异性、PPV、NPV和一致性百分比分别为96.7%、99.8%、98.9%、99.4%和99.3%。在研究期间使用的两种确认性PCR检测法之间未发现显著差异。本文讨论了Amplicor在检测淋病奈瑟菌方面的局限性以及在常规诊断环境中联合使用沙眼衣原体/淋病奈瑟菌PCR检测法的合理应用。
