Laboratory diagnosis of Pneumocystis carinii infections by PCR directed togenes encoding for mitochondrial 5S and 28S ribosomal RNA

PCR with 5S mitochondrial ribosomal RNA (5S) target is a sensitive and spec ific assay for the detection of Pneumocystis carinii in clinical specimens from the respiratory tract. We developed an oligonucleotide probe directed to a 200 bp amplicon generated by fungal-specific universal primers that an neals with sequrences specific for P. carinii in the 285 ribosomal RNA gene (285). Of 50 archived bronchoalveolar lavage (BAL) specimens, 46 of 50 sam ples (92% agreement) gave the same result (23 positive, 23 negative) by PCR directed to the 5S and 28S assays. Results of calcofluor white staining of BAL smears on slides indicated agreement with the molecular results in 43 of 46 (93.5%) assays. PCR detection of P. carinii by amplification of 28S r ibosomal gene target by fungal-specific primers and an organism-specific pr obe provides an alternate genomic target for the laboratory diagnosis of th is organism. (C) 1999 Elsevier Science Inc.