Use of the polymerase chain reaction for the diagnosis of invasive Candida infection

Molecular biology has had a strong impact on the field of microbiology. Recently these methods have emerged from the laboratory and have been applied to the area of clinical microbiology. The polymerase chain reaction (PCR) is a method of DNA amplification that has been used primarily in the research setting to detect pathogens which are generally found at low levels, are difficult to culture, or are difficult to identify. The dilemma in identifying Candida species in the bloodstream during an episode of disseminated disease leads to a greater incidence of morbidity and mortality due to disseminated nosocomial candidal infections in the compromised hosts. Using PCR to detect low levels of Candida DNA in the bloodstream early, rapidly, and accurately especially when the blood cultures are still negative, can provide definitive information beneficial to the management of disseminated candidiasis. However, before a PCR-based test for candidaemia can be used in the clinical laboratory, several problems have to be resolved.