Flinders Technology Associates (FTA) filter paper-based DNA extraction with Polymerase Chain Reaction (PCR) for detection of Pneumocystis jirovecii from respiratory specimens of immunocompromised patients

We evaluated the diagnostic value of Flinders Technology Associates (FTA) filter paper together with polymerase chain reaction (PCR) for detection of Pneumocystis jirovecii (carinii) from induced sputum (IS) and bronchoalveolar lavage fluid (BALF) samples. The study involved 162 patients with clinical diagnosis of pneumocystis pneumonia (PcP) of human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) patients and other immunocompromised patients. P. jirovecii cysts or trophozoites were detected in IS and BALF by cytological method. The mitochondrial 5S ribosomal ribonucleic acid (rRNA) gene of P. jirovecii was amplified from these samples by using FTA filters together with a one-step PCR method (FTA-PCR). With the FTA-PCR method, the sensitivity and specificity of the test compared to microscopic examination were 67% and 90% for IS, while they were 67% and 91% for BALF, respectively. The sensitivity and specificity of the FTA-PCR test was also comparable to PCR with the conventional deoxyribonucleic acid (DNA) extraction method. We concluded that FTA-PCR is useful to detect P. jirovecii in noninvasive IS.