Abstract Detail

Mycology

Burks, Caroline [1], Brewer, Marin [1].

Azole-resistant Aspergillus fumigatus in the environment: Identifying key reservoirs and hotspots of antifungal resistance.

Aspergillus fumigatus is an opportunistic human pathogen that causes aspergillosis, a spectrum of environmentally acquired respiratory illnesses. It has a cosmopolitan distribution and exists in the environment as a saprotroph on decaying plant matter. Azoles, which target Cyp51A in the ergosterol synthesis pathway, are the primary class of drugs used to treat aspergillosis. Azoles are also used to combat plant-pathogenic fungi in agricultural settings. Recently, an increasing number of azole-naïve patients have presented with pan-azole-resistant strains of A. fumigatus. The TR₃₄/L98H and TR₄₆/Y121F/T289A alleles in the cyp51A gene are the most common mutations conferring pan-azole resistance. There is evidence that these mutations arose in agricultural settings; therefore, numerous studies have been conducted to identify azole resistance in environmental A. fumigatus and to determine where resistance is developing in the environment. No reviews have yet summarized the global occurrence of azole-resistant A. fumigatus in the environment, so our review paper looked to use available literature to find trends and hotspots of global azole-resistant A. fumigatus. We also used information on the specific mutations identified, environmental settings, and azole fungicide use to create an interactive world map showing where resistant isolates have been detected. Azole-resistant A. fumigatus has been found on every continent except for Antarctica with the highest number of reports from Europe. We also found that developed environments, specifically hospitals and gardens, were the most common settings where azole-resistant A. fumigatus was detected, despite agricultural areas being the most frequently-sampled. The TR₃₄/L98H resistance allele was the most common mutation in all regions except South America where the TR₄₆/Y121F/T289A allele was the most common. However, a major consideration in interpreting this survey of the literature is sampling bias; regions and environments that have been extensively sampled are more likely to show greater azole resistance even though resistance could be more prevalent in areas that are under-sampled or not sampled at all. Increased surveillance to pinpoint reservoirs, as well as antifungal stewardship, are needed in order to find the easiest means of preventing this form of resistance from developing while preserving this class of antifungals for crop protection and human health.

Related Links:
Interactive Map

1 - University of Georgia, Plant Pathology, 2309 Miller Plant Sciences, Athens, GA, 30602, USA

Keywords:
Antifungal Resistance
Triazoles
Aspergillus fumigatus
global
Mycology.

Presentation Type: Oral Paper
Session: MY2, Mycology: Human and Animal Pathogens
Location: /
Date: Tuesday, July 20th, 2021
Time: 1:30 PM(EDT)
Number: MY2005
Abstract ID:513
Candidate for Awards:MSA Best Oral Presentation Award by a Graduate Student