Antifungal susceptibility of clinical isolates of 25 genetically confirmed Aspergillus species collected from Taiwan and Mainland China.

Abstract

To investigate the invitro antifungal susceptibilities of 25 genetically confirmed Aspergillus species collected from Taiwan and Mainland China. A total of 390 non-duplicate and consecutive Aspergillus isolates representing of 25 species recovered from clinical sources at two teaching hospitals in Taiwan and Mainland china were preserved for this study. Invitro antifungal susceptibility testing (AFST) of those Aspergillus isolates against seven antifungal agents was performed using Sensititre YeastOne (SYO) system. The susceptibility profiles of isolates were analyzed according to the general interpretation code drawn from the SYO instruction. The CYP51A gene sequencing analysis was performed for triazole-resistant Aspergillusfumigatus isolates. Among the 390 Aspergillus isolates, 76.7% (n=299) exhibited complete susceptibility to all the tested antifungals, and 23.3% (91/390) of different Aspergillus species isolates showed resistance to one or two classes of antifungal agents with higher minimum inhibitory concentrations (MICs) of >2mg/L. Resistance to amphotericin B was found in 91.2% (83/91) of those less susceptible isolates and most of them focused on species being resistant to Amphotericin B innately. The total rate of triazole resistance in this study was low (3.3%, 13/390), and only 3 (2.8%) A. fumigatus isolates were resistant to at least one of the triazoles with mutations of TR34/L98H or TR46/Y121F/T289A in CYP51A gene. The echinocandins were highly potent to the tested Aspergillus isolates. The existence of triazole resistance among A. fumigatus isolates in Taiwan and Mainland China indicates the need for continuous monitoring from now on.