Evaluation of Nested-PCR and Real-Time PCR assays for the diagnosis of Candidemia

K. Mohamed, H. Sellami, A. Sellami, S. Neji, F. Cheikhrouhou, F. Makni, A. Ayadi

Author address: 

HU Habib Bourguiba Sfax, Tunisia


PCR assays have a very low theoretical detection threshold and are therefore advocated for the diagnosis of fungemia. However, their effectiveness in this setting remains to be assessed. This study compared real-time PCR (Can-G) and nested-PCR assays with blood culture for the diagnosis of Candida spp. blood stream infections. A total of 200 clinical blood sample specimens obtained from 110 patients at risk to develop systemic fungal infection hospitalized in the University Hospital of Sfax (Tunisia) were submitted to culture, nested-PCR and real-time PCR. Blood culture was positive in 36 patients. When compared to culture, the Can-G assay (81% sensitivity, 96% specificity) performed better than the nested-PCR assay (86% sensitivity, 54% specificity). Conclusion: the real-time PCR assay, which avoids both contamination hazard with amplicons that cause false positive results and the use of time-consuming post PCR steps, appears more suitable than the nested-PCR assay for the laboratory diagnosis of yeast blood stream infections. In this study, real-time PCR did not enhance the sensitivity of the diagnosis of Candida spp. blood stream infection when compared to the conventional blood culture; however it might lead to earlier implementation of an adequately targeted antifungal treatment.

abstract No: 


Full conference title: 

4th Trends in Medical Mycology
    • TIMM 4th (2012)