Detection and Identification of Aspergillus fumigatus in BAL Samples of Patients with Suspected Tuberculosis by Nested-PCR

Aspergillus fumigatus is the cause of more than 90% of invasive pulmonary aspergillosis. The aim of this study is identification and detection of A. fumigatus in bronchoalveolar lavage (BAL) samples patients suspected to have tuberculosis by using of Nested-PCR. In this assay، a set of 100 BAL samples which were collected in 9 month، between the years 2012-2013، from patients with suspected tuberculosis in Tehran hospital، were examined by direct، culture and molecular tests. Manual phenol-chloroform method was used in order to extract DNA. Specific primers of Aspergillus genus and beta-actin primers were used for duplex-PCR. A pairs of internal primers were utilized in order to identification of A. fumigatus (Nested-PCR method). Finally، some of the PCR-products were sequenced for confirming results. Overall، 12 samples (12%) were aspergillus-positive by molecular test while 11% and 10% samples were positive by direct and culture test، respectively. The sensitivities and specificities of PCR method compare with direct examination was 100% and 98. 8%، respectively. The study also showed that sensitivities and specificities of PCR method compare with culture was 100% and 97. 7%، respectively. After sequencing PCR product sample، isolated species were recognized as A. fumigatus. This study showed that PCR method in compare with the direct method and the culture has a higher sensitivity in the detection of Aspergillus species، also Present study displayed that can be consider Aspergillus species and A. fumigatus in suspicious to tuberculosis BAL samples