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

Background and Aim: 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. Materials and Methods: 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. 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. Conclusions: 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