Z Kamali Sarwestani1, S J Hashemi1, S Rezaie1, M Gerami Shoar1, S Mahmoudi2, M Elahi3, M Bahardoost4, A Tajdini3, S Abutalebian5, R Daie Ghazvini6. 1. Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Pour Sina st., Keshavarz Blvd., Tehran, Iran. 2. Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Pour Sina st., Keshavarz Blvd., Tehran, Iran; Students' Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran. 3. Department of Head and Neck surgery, AmirAlam Hospital, Tehran University of Medical Sciences, Tehran, Iran. 4. Colorectal research center, Iran University of Medical Sciences, Tehran, Iran; Department of Epidemiology and Biostatistics, School of Medicine, Iran University of Medical Sciences, Tehran, Iran. 5. Department of Medical Parasitology and Mycology, School of Medicine, Isfahan University of Medical Science, Isfahan, Iran. 6. Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Pour Sina st., Keshavarz Blvd., Tehran, Iran. Electronic address: rdaie@tums.ac.ir.
Abstract
INTRODUCTION: Aspergillus niger is the most commonly reported etiology of otomycosis based on morphological characteristics. This fungus is a member of Aspergillus section Nigri, a set of morphologically indistinguishable species that can harbor various antifungal susceptibility patterns. The aim of this study was to accurately identify and determine the susceptibility pattern of a set of black aspergilli isolated from otomycosis patients. METHODS: Forty-three black Aspergillus isolates from otomycosis patients were identified by using the PCR-sequencing of the β-tubulin gene. Furthermore, the susceptibility of isolates to three antifungal drugs, including fluconazole (FLU), clotrimazole (CLT) and nystatin (NS), were tested according to CLSI M38-A2. The data were analyzed using the SPSS software (version 15). RESULTS: The majority of isolates were identified as A. tubingensis (32/43, 74.42%) followed by A. niger (11/43, 25.58%). The lowest minimum inhibitory concentration (MIC) values were observed for NS with geometric means (GM) of 4.65μg/mL and 4.83μg/mL against A. tubingensis and A. niger isolates, respectively. CLT showed wide MIC ranges and a statistically significant inter-species difference was observed between A. tubingensis and A. niger isolates (P<0.05). FLU was inactive against both species with GMs>64μg/mL. CONCLUSION: Species other than A. niger can be more frequent as observed in our study. In addition, considering the low and variable activity of tested antifungal drugs, empirical treatment can result in treatment failure. Accurate identification and antifungal susceptibility testing of isolates is, however, recommended.
INTRODUCTION:Aspergillus niger is the most commonly reported etiology of otomycosis based on morphological characteristics. This fungus is a member of Aspergillus section Nigri, a set of morphologically indistinguishable species that can harbor various antifungal susceptibility patterns. The aim of this study was to accurately identify and determine the susceptibility pattern of a set of black aspergilli isolated from otomycosispatients. METHODS: Forty-three black Aspergillus isolates from otomycosispatients were identified by using the PCR-sequencing of the β-tubulin gene. Furthermore, the susceptibility of isolates to three antifungal drugs, including fluconazole (FLU), clotrimazole (CLT) and nystatin (NS), were tested according to CLSI M38-A2. The data were analyzed using the SPSS software (version 15). RESULTS: The majority of isolates were identified as A. tubingensis (32/43, 74.42%) followed by A. niger (11/43, 25.58%). The lowest minimum inhibitory concentration (MIC) values were observed for NS with geometric means (GM) of 4.65μg/mL and 4.83μg/mL against A. tubingensis and A. niger isolates, respectively. CLT showed wide MIC ranges and a statistically significant inter-species difference was observed between A. tubingensis and A. niger isolates (P<0.05). FLU was inactive against both species with GMs>64μg/mL. CONCLUSION: Species other than A. niger can be more frequent as observed in our study. In addition, considering the low and variable activity of tested antifungal drugs, empirical treatment can result in treatment failure. Accurate identification and antifungal susceptibility testing of isolates is, however, recommended.
Authors: B Carrara; R Richards; S Imbert; F Morio; M Sasso; N Zahr; A C Normand; P Le Pape; L Lachaud; S Ranque; D Maubon; R Piarroux; A Fekkar Journal: Antimicrob Agents Chemother Date: 2020-06-23 Impact factor: 5.191