Distribution and diversity of Alt a ۱ gene in Alternaria species isolated from outdoor air of Tehran

Background and Aim: In the present study, distribution pattern and phylogeny of Alternaria species isolated from Tehran air was determine based on the homology of Alt a۱ gene. Materials and Methods: A number of ۴۸ Alternaria isolates belonging to  A. alternata (۳۳.۴%), A. solani (۲۳%), A. tenuissima (۲۳%), A. porri (۱۶.۶%), and  A. brassicicola (۴%) obtained from Tehran air were cultured on Sabouraud dextrose agar. Genomic DNA was extracted from the isolates and amplified with forward and reverse specific primers of Alt a۱ gene. The resultant fragments of ۵۰۰ to ۶۰۰ bp of genomic DNA were sequenced and compared with genomic data of NCBI gene bank to evaluate phylogenetic relationship of Alternaria species. Results: Based on the resulting dendrogram, isolates belonging to A. alternata and A. solani were distributed in ۴ clusters and those of A. brassicicola, A. porri, and A. tenuissima each in ۲ clusters. Approximately, ۸۱% of A. alternata isolates, ۷۳% of A. solani isolates, ۴۵.۵% of A. tenuissima isolates and ۱۲.۵% of A. porri isolates showed a similarity of ۹۹% and resided in clusters I, II, IV and VII, respectively. Conclusions: Our results indicated that Alt a۱ gene was present in all examined species and differences of sequence similarities of this gene shows the importance of species and strains of Alternaria in induction of allergenic reactions in suspected patients especially those with allergic asthma.

کلیدواژه ها:

Alternaria species ، Allergen ، Diversity ، Alt a۱ gene ، Tehran ، گونه های آلترناریا ، آلرژن ، تنوع ، ژن Alt a۱ ، تهران