Azole-Containing Agar Plates and Antifungal Susceptibility Testing for the Detection of Azole-Resistant Aspergillus Species in Hospital Environmental Samples

Article Authors: Mona Ghazanfari, Mahdi Abastabar, Iman Haghani, Maryam Moazeni, Shakiba Hedayati, Sanaz Yaalimadad, Bahador Nikoueian Shirvan, Felix Bongomin, and Mohammad T. Hedayati


The indoor environment of hospitals should be considered as an important reservoir of azole resistant Aspergillus species. In this study, we evaluated azole-containing agar plates (ACAPs) and antifungal susceptibility testing (AFST) for the detection of azole-resistant Aspergillus species in hospital environmental samples. Between September 2021 and January 2022, environmental samples (108 instruments and 12 air) were collected from different wards of 4 educational hospitals in Mazandaran province, Iran. All samples were cultured using ACAPs. Recovered Aspergillus isolates were molecularly identified at species level using partial DNA sequencing of beta-tubulin gene. AFST of Aspergillus species was performed using the Clinical and Laboratory Standards Institute M38-A3 guideline. Screening for cyp51A mutations was also done. Overall, 18 (15.0%) isolates of Aspergillus species were recovered from ACAPs, of which Aspergillus tubingensis (50%) and Aspergillus fumigatus (38.9%) were the commonest species. No isolate of Aspergillus species grew on posaconazole (PCZ)-containing agar plates. Among the 18 Aspergillus isolated species from ACAPs, 83.3% were related to samples from instruments. Of the nine isolates of A. tubingensis, 22.2% and 44.4% isolates showed minimum inhibitory concentration (MIC) = 2 μg/mL against voriconazole (VCZ) and itraconazole, respectively; and 44.4% isolates showed MIC = 1 μg/mL against PCZ. Of the seven isolates of A. fumigatus, one (14.3%) was resistant to VCZ. This isolate showed F46Y, G54E, G138C, M172V, M220I, D255E, T289F, G432C, and G448S mutation in cyp51A. Our finding showed the emergence of high MICs in cryptic and non-fumigatus species of Aspergillus such as A. tubingensis and VCZ resistance in A. fumigatus in indoor environment of hospitals.

Bibliographical metadata

Volume 29
Issue No. 12
Related Faculties/Schools

Mona Ghazanfari 1 2Mahdi Abastabar 1 2Iman Haghani 1Maryam Moazeni 1 2Shakiba Hedayati 3Sanaz Yaalimadad 1 2Bahador Nikoueian Shirvan 1 2Felix Bongomin 4Mohammad T Hedayati 1 2

1 Invasive Fungi Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran.
2 Department of Medical Mycology, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran.
3 Student Research Committee Center, Mazandaran University of Medical Sciences, Sari, Iran.
4 Department of Medical Microbiology and Immunology, Faculty of Medicine, Gulu University, Gulu, Uganda.