Detection of surgical pathogens by in vitro DNA amplification. Part I. Rapid identification of Candida albicans by in vitro amplification of a fungus-specific gene.

The management of candidemia and disseminated candidiasis depends on rapid, unambiguous identification of Candida. Such identification is retarded by the slow growth of Candida from clinical specimens. Administration of effective but potentially toxic antifungal therapy is often withheld pending identification. To circumvent this slow growth and thus to expedite diagnosis and therapy, the polymerase chain reaction (PCR) was used to amplify a segment of fungal DNA coding for the cytochrome P450L1A1 (lanosterol-14 alpha-demethylase) in vitro. The technique provides unambiguous evidence of C. albicans in as few as 6 hours with a detection threshold of 10 organisms in a 100 mu specimen. Clinical specimens of urine (n = 4), sputum (n = 6), wound fluid (n = 1, and blood (n = 2) were collected from patients, and C. albicans was conventionally documented at these sites; in each case, PCR was confirmed. Of 17 additional specimens that were culture negative, PCR suggested the presence of yeast in two of the specimens. PCR-based detection of surgical pathogens may have broad application in rapid screening for the presence of organisms either indigenous to a particular surgical intensive care unit or peculiar to selected patient populations.