Detection and identification of Candida sp. by PCR in candidemia diagnosis

Abstract

Summary The polymerase chain reaction was used for targeting species-specific sequences rDNA of five medical important yeasts most common isolated from blood. Objectives Evaluate the potential value of the nested PCR in species detection and identification of Candida sp. from patients at risk. Patients and methods One hundred and fifty seven samples were drawn from 76 patients who were at risk for developing candidiasis hospitalized at Habib-Bourguiba Sfax hospital and from 20 healthy volunteers. Each sample was used simultaneously for conventional fungal blood culture and for detection and identification of Candida DNA by nested PCR. Results Forty-nine patients were PCR positive. Nineteen of these patients were culture positive. One patient having candidemia due to Candida guillermondii has not been identified by our targeting nested PCR. The limit of detection of our targeting nested PCR was 1 fg from the five corresponding Candida sp. Conclusions The molecular method is significantly more sensitive and proved to be both simple and reproducible. It may offer potential advantages over conventional fungal blood cultures, especially in the therapeutic decision.