Molecular and morphological Identification of Aspergillus section Terrei isolated from pistachio nut

E. Sedaghati1, M. J. Nikkhah2 , R. Zare3

Author address: 

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Abstract: 

Background: Aspergillus terreus is a common soil saprophyte that has been recovered from desert soil, grasslands, and compost heaps, as well as contaminants of stored corn, barley, peanuts and pistachio. This species is also clinically significant, causing infections ranging from superficial to invasive infections. A. terreus belongs to the genus Aspergillus, sub-genus Nidulantes. The aim of this study evaluation of molecular and morphological identification of Aspergillus section Terrei isolated from pistachio nut. Materials and methods: Samples were taken from pistachio orchards of the most important producing provinces in Iran. About 300 samples were taken including fresh fruits, dried fruits, leaves, new and old wastages. Single conidial heads were chosen according to their phenotype, and subcultured repeatedly on Malt Extract Agar media until complete purification. Altogether, 12 isolates belong to Section Terrei were purified. Molecular Identification carried out using partial sequencing of Calmodulin gene. Phylogenetic tree were drew using MEGA 4 software. Results: all isolate belong to section Terrei members have Colonies yellowish-brown to cinnamonbrown on Czapek Dox Agar and identified as A. terreus according to their morphological characteristics. On Czapek media culture after seven days: colony diameter, 35-38 mm, conidial head, short columnar, 10-65μ length, conidiophores, smooth, 105-320μ, vesicle spatulate 8-19μ diameter, strigma biseriate, conidia, spherical, smooth, 2-2.2μ, Accossory conidia are available in colony. Phylogenetic analysis of calmodulin gene also showed the same results as morphological identification. Conclusion: according recent polyphasic taxonomy, new species such as A. niveus, A. carneus reported in this section. These species are not distinguishable from A. terreus by morphological criterias, therefore molecular methods is essential for final identification. Keywords: Aspergillus, A. terreus, phylogeny, Taxonomy, pistachio
2011

abstract No: 

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Full conference title: 

Iranian Congress on Medical Mycology
    • ICMM 2011