Molecular Identification of Causative Agents in 25 Cases with Mucormycosis in Iran

Abstract

Background: Mucormycosis is a life-threatening infection due to the members of the Mucorales order with increasing incidence during the last decades. Rhizopus spp. are the most common causes of disease; however, this infection could be developed by various other species. Objectives: This study presented the clinical features and predisposing factors of several patients with mucormycosis along with the causative agents using sequence analysis. Methods: Clinical specimens of 25 cases with mucormycosis were included in this study. Direct examination and culture were performed for all specimens and then isolated fungi were identified based on their morphology and sequence analysis of ribosomal DNA. Results: The patients were comprised of 17 (68) females and 8 (32) males with the mean age of 47.16 +/- 17.4 years. Rhino-cerebral mucormycosis was the most common clinical form (24 cases) followed by pulmonary mucormycosis (one case). Diabetes mellitus was the most common predisposing factor (n = 17, 68). The culture was positive in 15 specimens and the isolated fungi were morphologically identified as Rhizopus spp., subsequently, all of the isolates were identified as Rhizopus oryzae at the species level using the molecular method. Conclusions: Diabetes and R. oryzae played the most important roles as the predisposing factor and etiologic agent of mucormycosis, respectively.