Comparison of the FXG (TM): RESP (Asp plus ) real-time PCR assay with direct immunofluorescence and calcofluor white staining for the detection of Pneumocystis jirovecii in respiratory specimens

作者：Seah Christine; Richardson Susan E; Tsui George; Yu Billy; Thornback John; McTaggart Lisa; Boggild Andrea; Wengenack Nancy L; Zhang Sean X^*

来源：Medical Mycology, 2012, 50(3): 324-327.

DOI：10.3109/13693786.2011.598878

• Pneumocystis jirovecii
• PCR
• immunofluorescence
• calcofluor white
• detection

We compared the FXG (TM): RESP (Asp +) real-time PCR assay (Myconostica Ltd) with two microscopic staining methods (direct immunofluorescence [IFA] and calcofluor white) for the detection of Pneumocystis jirovecii in 411 respiratory specimens submitted for P. jirovecii examination. We considered the specimen to be microscopically positive if the organism could be visualized through the use of either IFA or calcofluor white. A second, published real-time PCR assay targeting the cdc2 gene of P. jirovecii was used to adjudicate those specimens that were microscopically negative but Myconostica PCR positive. The Myconostica PCR positive samples were deemed to be true positives if they were concordant with microscopically positive results or if they were positive by the second PCR assay. As a result, the Myconostica PCR assay was found to be more sensitive than the two microscopy methods in detecting P. jirovecii (10.5% true positivity rate by PCR, 8.0% by immunofluorescence, and 7.1% by calcofluor white). The Myconostica PCR assay showed 93.5% sensitivity, 95.1% specificity, 70.5% positive predictive value, and 99.1% negative predictive value. Its high negative predictive value suggests a role of the Myconostica PCR assay in ruling out Pneumocystis pneumonia.

• 出版日期2012-4