Aspergillus flavus: human pathogen, allergen and mycotoxin producer

Abstract

Aspergillus infections have grown in importance in the last years. However, most of the studies have focused on Aspergillus fumigatus, the most prevalent species in the genus. In certain locales and hospitals, Aspergillus flavus is more common in air than A. fumigatus, for unclear reasons. After A. fumigatus, A. flavus is the second leading cause of invasive aspergillosis and it is the most common cause of superficial infection. Experimental invasive infections in mice show A. flavus to be 100-fold more virulent than A. fumigatus in terms of inoculum required. Particularly common clinical syndromes associated with A. flavus include chronic granulomatous sinusitis, keratitis, cutaneous aspergillosis, wound infections and osteomyelitis following trauma and inoculation. Outbreaks associated with A. flavus appear to be associated with single or closely related strains, in contrast to those associated with A. fumigatus. In addition, A. flavus produces aflatoxins, the most toxic and potent hepatocarcinogenic natural compounds ever characterized. Accurate species identification within Aspergillus flavus complex remains difficult due to overlapping morphological and biochemical characteristics, and much taxonomic and population genetics work is necessary to better understand the species and related species. The flavus complex currently includes 23 species or varieties, including two sexual species, Petromyces alliaceus and P. albertensis. The genome of the highly related Aspergillus oryzae is completed and available; that of A. flavus in the final stages of annotation. Our understanding of A. flavus lags far behind that of A. fumigatus. Studies of the genomics, taxonomy, population genetics, pathogenicity, allergenicity and antifungal susceptibility of A. flavus are all required.

Contribution of ATPase copper transporters in animal but not plant virulence of the crossover pathogen Aspergillus flavus

“…However, a prominent fungal exception to this rarity is A. flavus which not only causes toxic seed diseases but also is a common agent of keratitis as well as a frequent pathogen of immunosuppressed patients [26,38]. This fungus is common in agricultural soils and hard to eliminate from that environment due to formation of resistant overwintering structures called sclerotia.…”

“…to infect immunosuppressed patients after A. fumigatus [26] as well as being a frequent cause of trauma-associated keratitis in agricultural workers [27]. Aspergillus flavus is also notorious for its ability to colonize lipid-rich seed resulting in contamination of food and feed crops with the carcinogenic mycotoxin, aflatoxin [28] This dual ability to cause disease in both animals and plants, leading to enormous agricultural economic losses and health problems, exacerbates the importance of A. flavus as an opportunistic pathogen.…”

Fungi diversity in PM<sub>2. 5</sub> and PM<sub>1</sub> at the summit of Mt. Tai: abundance, size distribution, and seasonal variation

“…Aspergillus flavus is a common human pathogen found in air, and it is also a human allergen and mycotoxin producer (Adhikari et al, 2004). It is associated with invasive aspergillosis and superficial infections (Hedayati et al, 2007). Blumeria graminis, found on the surface of plant leaves, causes powdery mildew on cereal plants (Belanger et al, 2003).…”

Detection of Alternative Splice Variants at the Proteome Level in Aspergillus flavus

“…The genome contains 13 071 predicted genes and the mean gene length is 1384 bp. 25 The bottom-up and top-down proteomic profiles of A. flavus under different temperatures have already been surveyed through a SILAC approach. 26,27 It has been reported that intron splicing is essential for amineregulated gene expression in Aspergillus oryzae, 28 a widely used industrial and food fungus which is almost genetically identical to A. flavus.…”