Tehran University of Medical Sciences

Science Communicator Platform

Stay connected! Follow us on X network (Twitter):
Share By
Genetic Diversity and in Vitro Antifungal Susceptibility of 200 Clinical and Environmental Aspergillus Flavus Isolates Publisher Pubmed



Taghizadeharmaki M1, 2, 3 ; Hedayati MT1, 2 ; Ansari S4 ; Omran SM3 ; Saber S5 ; Rafati H6 ; Zoll J7, 8 ; Van Der Lee HA7, 8 ; Melchers WJG7, 8 ; Verweij PE7, 8 ; Seyedmousavi S1, 7, 8, 9
Authors

Source: Antimicrobial Agents and Chemotherapy Published:2017


Abstract

Aspergillus flavus has been frequently reported as the leading cause of invasive aspergillosis in certain tropical and subtropical countries. Two hundred A. flavus strains originating from clinical and environmental sources and collected between 2008 and 2015 were phylogenetically identified at the species level by analyzing partial β-tubulin and calmodulin genes. In vitro antifungal susceptibility testing was performed against antifungals using the European Committee on Antimicrobial Susceptibility Testing (EUCAST) broth microdilution method. In addition, genotyping was performed using a short-tandem-repeat (STR) assay of a panel of six microsatellite markers (A. flavus 2A, 2B, 2C, 3A, 3B, and 3C), in order to determine the genetic variation and the potential relationship between clinical and environmental isolates. The geometric means of the minimum inhibitory concentrations/minimum effective concentrations (MICs/MECs) of the antifungals across all isolates were (in increasing order): posaconazole, 0.13 mg/liter; anidulafungin, 0.16 mg/liter; itraconazole, 0.29 mg/liter; caspofungin, 0.42 mg/liter; voriconazole, 0.64 mg/liter; isavuconazole, 1.10 mg/liter; amphotericin B, 3.35 mg/liter; and flucytosine, 62.97 mg/liter. All of the clinical isolates were genetically different. However, an identical microsatellite genotype was found between a clinical isolate and two environmental strains. In conclusion, posaconazole and anidulafungin showed the greatest in vitro activity among systemic azoles and echinocandins, respectively. However, the majority of the A. flavus isolates showed reduced susceptibility to amphotericin B. Antifungal susceptibility of A. flavus was not linked with the clinical or environmental source of isolation. Microsatellite genotyping may suggest an association between clinical and environmental strains, although this requires further investigation. Copyright © 2017 American Society for Microbiology. All Rights Reserved.
Other Related Docs
13. A Review on Molecular Typing Methods for Aspergillus Species, Journal of Mazandaran University of Medical Sciences (2015)