Electronic equipment and appliances in special wards of hospitals as a source of azole-resistant Aspergillus fumigatus: a multi-centre study from Iran

Abstract

Azole-resistant Aspergillus fumigatus (ARAf), reported as a global public health concern, has been unexpectedly observed in different countries. To identify ARAf and detect azole resistance related to the CYP51A mutation in different hospital environmental samples. In this multi-centre study from Iran, surfaces of electronic equipment and appliances from different hospitals in Iran were sampled using cotton swabs. All samples were cultured using azole-containing agar plates (ACAPs). Recovered Aspergillus isolates were identified at the species level using partial DNA sequencing of the β-tubulin gene. The azole susceptibility testing of A.fumigatus isolates was performed using the Clinical and Laboratory Standards Institute M38-A3 guideline. The sequencing of the CYP51A gene was also performed to detect mutations related to resistance. Out of the 693 collected samples, 89 (12.8%) Aspergillus species were recovered from ACAPs. Aspergillus fumigatus (41.6%) was the most prevalent, followed by A.tubingensis (23.6%) and A.niger (15.6%). Among 37 isolates of A.fumigatus, 19 (51.3%) showed high minimum inhibitory concentration (MIC) values to at least one of the three azoles, voriconazole, itraconazole, and posaconazole. CYP51A polymorphisms were detected in all 19 isolates, of which 52.6% showed the TR34/L98H mutation. Other detected mutations were G432C, G448S, G54E/G138C, F46Y, and Y121F/M220I/D255E. T289F and G432C were the first reported mutations in ARAf. There was a considerable level of azole resistance in hospital environmental samples, a serious warning for patients vulnerable to aspergillosis. Our findings have also revealed a different mutation pattern in the CYP51A gene.