Department of Infectious Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, Viale Regina Elena 299, Rome, Italy.
Diagn Microbiol Infect Dis. 2012 Jun;73(2):111-20. doi: 10.1016/j.diagmicrobio.2012.02.022. Epub 2012 Apr 10.
With the recognition of several diphtheria outbreaks and the emergence of nontoxigenic corynebacteria strains, there has been renewed interest in the development of laboratory diagnostic methods. Previously reported polymerase chain reaction (PCR) assays can have low diagnostic sensitivity or give species misidentifications among clinical isolates. The aim of the present study was the development of combined real-time PCR assays, based on the tox and rpoB genes, for the detection and differentiation of toxigenic and nontoxigenic corynebacteria. By the PCR tox assay, it was possible to perform the direct identification of DT tox gene of Corynebacterium diphtheriae and Corynebacterium ulcerans, while the PCR rpoB assay differentiated C. diphtheriae from C. ulcerans, irrespective of their toxigenic status. In addition, we detected the DT toxin of Corynebacterium pseudotuberculosis for the first time. These assays revealed high sensitivity, specificity, and reproducibility, and the availability of plasmid controls will facilitate further research into the diagnostics of diphtheria corynebacteria.
随着对几场白喉爆发和非产毒棒状杆菌菌株的认识，人们对实验室诊断方法的发展重新产生了兴趣。以前报道的聚合酶链反应（PCR）检测方法可能具有较低的诊断灵敏度，或者在临床分离株中出现种属错误鉴定。本研究旨在开发基于 tox 和 rpoB 基因的组合实时 PCR 检测方法，用于检测和区分产毒和非产毒棒状杆菌。通过 PCR tox 检测方法，可以直接鉴定白喉棒状杆菌和溃疡棒状杆菌的 DT 毒素基因，而 PCR rpoB 检测方法可以区分白喉棒状杆菌和溃疡棒状杆菌，无论其产毒状态如何。此外，我们首次检测到了假结核棒状杆菌的 DT 毒素。这些检测方法显示出高灵敏度、特异性和可重复性，质粒对照的可用性将有助于进一步研究白喉棒状杆菌的诊断。
