Application of PCR combined with reverse line blot assay in detection and identification of common pathogenic Aspergillus in fungal sinusitis

Objective To evaluate the feasibility of PCR/reverse line blot hybridization (RLB) assay in the detection and identification of clinical pathogens in fungal sinusitis (FS).Methods Twenty- six formalin-fixed and paraffin-embedded tissues and 8 fresh tissues of FS were collected from Beijing Tongren Hospital,Capital Medical University from May 2009 to February 2010.Pathological examination,fungal culture and ITS2 region sequencing were carried out.The DNA of all samples was extracted by standard procedure and fungal universal primers ITS3 and ITS4 were used for PCR amplification of all tissues.Then the amplified products were used for RLB with five fungal species-specific probes.The results of PCR/RLB were compared with ITS region sequencing,fungal culture and pathological examination.Results For the biopsy tissues,fungal cultures were positive in 14 cases (41.2％); pathologic examination demonstrated fungal hyphae in all cases; ITS2 region sequencing was successful in 16 cases (47.1％) ; PCR/RLB showed A.flavus in 14 cases,A.fumigatus in 10 cases,A.niger in four cases,A.nidulans in one case,A.flavus and A.fumigatus in three cases,and A.fumigatus and A.niger in two cases.Conclusions The PCR/RLB assay is suitable for rapid and accurate detection and identification of the pathogenic fungus of FS.Compared with the conventional fungal culture and microscopy,pathologic examination and DNA sequencing,the PCR/RLB has the advantages of more economy,time saving,and higher sensitivity,specificity and throughput. Key words: Sinusitis;  Aspergillosis;  Polymerase