Elevated Prevalence of Azole-Resistant Aspergillus fumigatus in Urban versus Rural Environments in the United Kingdom.

Azole resistance in the opportunistic pathogen is increasing, dominated primarily by the following two environmentally associated resistance alleles: TR/L98H and TR/Y121F/T289A. By sampling soils across the South of England, we assess the prevalence of azole-resistant (AR) in samples collected in both urban and rural locations. We characterize the susceptibility profiles of the resistant isolates to three medical azoles, identify the underlying genetic basis of resistance, and investigate their genetic relationships. AR was detected in 6.7% of the soil samples, with a higher prevalence in urban (13.8%) than rural (1.1%) locations. Twenty isolates were confirmed to exhibit clinical breakpoints for resistance to at least one of three medical azoles, with 18 isolates exhibiting resistance to itraconazole, 6 to voriconazole, and 2 showing elevated minimum inhibitory concentrations to posaconazole. Thirteen of the resistant isolates harbored the TR/L98H resistance allele, and six isolates carried the TR/Y121F/T289A allele. The 20 azole-resistant isolates were spread across five genetic subtypes, t01, t02, t04B, t09, and t18 with t02 being the predominant subtype. Our study demonstrates that AR can be easily isolated in the South of England, especially in urban city centers, which appear to play an important role in the epidemiology of environmentally linked drug-resistant .