Comparison of PCR protocols for detecting Histoplasma capsulatum DNA through a multicenter study.

BACKGROUND

A multicenter study was conducted. A panel containing DNA from Histoplasma capsulatum, as well as negative and cross-reaction controls, was sent to five different laboratories, members of the MICOMOL network from CYTED Program.

AIMS: The objective was to assess the accuracy of different PCR protocols to detect H. capsulatum DNA.

METHODS

Seven different PCR protocols were tested. They were based on PCR techniques and used unicopy and multicopy targets.

RESULTS

Most of these protocols (4/7) were able to detect the smallest amounts of fungal DNA (10(2)fg/μl). Overall sensitivity was 86% and specificity was 100%. The protocol based on a unicopy target (SCAR220) presented lower sensitivity (43%) but 100% specificity. The real-time protocols tested were highly reproducible, sensitive, and specific. Neither false positives nor cross-reactions were detected in any protocol.

CONCLUSIONS

All laboratories were able to amplify H. capsulatum DNA, and real-time PCR seems to be a promising tool to efficiently detect this pathogen in clinical samples.