Parasitologie-Mycologie, Centre Hospitalier Universitaire l'Archet, INSERM, U1065, C3M, Virulence Microbienne et Signalisation Inflammatoire-Université de la Côte d'Azur, Faculté de Médecine, Nice, France
Palo Alto Medical Foundation Toxoplasma Serology Laboratory, National Reference Center for the Study and Diagnosis of Toxoplasmosis, Palo Alto, California, USA.
J Clin Microbiol. 2020 Jan 28;58(2). doi: 10.1128/JCM.01223-19.
DNA detection is essential to antenatally diagnose a congenital infection and reactivation of a past infection in an immunocompromised patient. Initially, PCR methods targeted the 35-fold repetitive B1 gene, and more recently, coding sequence Rep 529 has been preferred, as it was reported to be repeated 200- to 300-fold and yielded far better sensitivity than amplification of the B1 sequence. To date, few data are available in regard to the efficacy of Rep 529 for non-type II genotypes. In this study, we compared the results of B1 quantitative PCR (qPCR) with those of two different Rep 529 qPCRs performed on 111 samples in two different laboratories (Rep 529-1 and Rep 529-2). The performances of the 3 qPCRs were also compared according to the genotypes of the isolates for 13 type II and 21 non-type II samples. The performance of the Rep 529 target was superior to that of the B1 target regardless of the genotype (threshold cycle [ ] values for the Rep 529-1 and Rep 529-2 qPCRs were lower than those for the B1 qPCR [ < 0.001 and < 0.01, respectively]). The same results were observed when a comparison was made according to the genotype of the strain (type II and non-type II genotypes). To our knowledge, these results provide the first relative quantitative data revealing that the efficiency of Rep 529 qPCR does not depend on the genotype of isolates and that, in fact, it is superior to B1 qPCR.
DNA 检测对于产前诊断免疫功能低下患者的先天性感染和既往感染的再激活至关重要。最初，PCR 方法针对 35 倍重复的 B1 基因，而最近，编码序列 Rep 529 被优先使用，因为据报道它重复 200-300 倍，并且比扩增 B1 序列的灵敏度更高。迄今为止，有关 Rep 529 对非 II 型基因型的有效性的数据很少。在这项研究中，我们比较了两种不同实验室（Rep 529-1 和 Rep 529-2）的 111 个样本中 B1 定量 PCR（qPCR）和两种不同 Rep 529 qPCR 的结果。根据 13 个 II 型和 21 个非 II 型样本的分离株基因型，还比较了这 3 种 qPCR 的性能。无论基因型如何（Rep 529-1 和 Rep 529-2 qPCR 的阈值周期[ ]值均低于 B1 qPCR [ < 0.001 和 < 0.01，分别）），Rep 529 靶标的性能均优于 B1 靶标。当根据菌株的基因型（II 型和非 II 型基因型）进行比较时，观察到相同的结果。据我们所知，这些结果提供了第一个相对定量数据，表明 Rep 529 qPCR 的效率不依赖于分离株的基因型，实际上它优于 B1 qPCR。
