Extrolites of <i>Aspergillus fumigatus</i> and Other Pathogenic Species in <i>Aspergillus </i>Section <i>Fumigati</i>

Aspergillus fumigatus is an important opportunistic human pathogen known for its production of a large array of extrolites. Up to 63 species have been described in Aspergillus section Fumigati, some of which have also been reliably reported to be pathogenic, including A. felis, A. fischeri, A. fumigatiaffinis, A. fumisynnematus, A. hiratsukae, A. laciniosus, A. lentulus, A. novofumigatus, A. parafelis, A. pseudofelis, A. pseudoviridinutans, A. spinosus, A. thermomutatus, and A. udagawae. These species share the production of hydrophobins, melanins, and siderophores and ability to grow well at 37°C, but they only share some small molecule extrolites, that could be important factors in pathogenicity. According to the literature gliotoxin and other exometabolites can be contributing factors to pathogenicity, but these exometabolites are apparently not produced by all pathogenic species. It is our hypothesis that species unable to produce some of these metabolites can produce proxy-exometabolites that may serve the same function. We tabulate all exometabolites reported from species in Aspergillus section Fumigati and by comparing the profile of those extrolites, suggest that those producing many different kinds of exometabolites are potential opportunistic pathogens. The exometabolite data also suggest that the profile of exometabolites are highly specific and can be used for identification of these closely related species

Taxonomy, chemodiversity, and chemoconsistency of Aspergillus, Penicillium, and Talaromyces species

Aspergillus, Penicillium and Talaromyces are among the most chemically inventive of all fungi, producing a wide array of secondary metabolites (exometabolites). The three genera are holophyletic in a cladistic sense and polythetic classes in an anagenetic or functional sense, and contain approximately 300, 500 and 120 species, respectively. New developments in classification, cladification and nomenclature have meant that the species, series and sections are natural groups that share many extrolites, including exometabolites, exoproteins, exocarbohydrates and exolipids in addition to morphological features. The number of secondary metabolites reported from these species is very large, and genome sequencing projects have shown that a large number of additional exometabolites may be expressed, given the right conditions (silent gene clusters for exometabolites). The exometabolites are biosynthesized via shikimic acid, tricarboxylic acid cycle members, nucleotides, carbohydrates, or as polyketides, nonribosomal peptides or mixtures of those. The gene clusters coding for these compounds contain genes for the biosynthetic building blocks, the linking of these building blocks, tailoring enzymes, resistance for own products, and exporters. Species within a series or section in Aspergillus, Penicillium and Talaromyces have many exometabolites in common, seemingly acquired by cladogenesis, but many autapomorphic exometabolites may have been acquired by horizontal gene transfer. Despite genome sequencing efforts, and the many break-throughs these will give, it is obvious that epigenetic factors play a large role in evolution and function of chemodiversity, and better methods for characterizing the epigenome are needed. Most of the individual species of the three genera produce a consistent and characteristic profile of exometabolites, but epigenetic and growth medium variations, stimulation by exometabolites from other species, and variations in abiotic intrinsic and extr

Comments on "Screening and identification of novel ochratoxin A-producing fungi from grapes. Toxins 2016,8,833" - in reporting ochratoxin A production from strains of Aspergillus, Penicillium and talaromcyes

Recently a species in the genus Talaromyces, a uniseriate species of Aspergillus section Nigri and an isolate each of two widespread species, Penicillium rubens and P. commune, were reported to produce ochratoxin A. This claim was based on insufficient biological and chemical data. We propose a list of criteria that need to be met before an unexpected mycotoxin producer is reported. There have only been convincing data on ochratoxin A production for Penicillium verrucosum, P. nordicum, P. thymicola, all from Penicillium series Verrucosa, and from species in three sections of Aspergillus: section Circumdati, section Nigri and section Flavi

Comments on "Mycobiota and Mycotoxins in Traditional Medicinal Seeds from China. Toxins 2015, 7, 3858-3875"-in Attributing Ochratoxin A Biosynthesis Within the Genus <i>Penicillium </i>Occurring on Natural Agricultural Produce

The unusual attribution of trace amounts of ochratoxin A in some Chinese food commodities to Penicillium polonicum is questioned by European experience in searches for ochratoxinogenic food-spoilage Penicillia, where mistaken attribution is now known to have been due to cryptic Penicillium verrucosum contamination. Consequently, selection of single-spore isolates is recommended as pre-requisite for attributing mycotoxin biosynthetic potential to fungi