The genus Aureobasidium, which is known as a wood staining mould, has been detected on oil treated woods in the specific stain formation called biofinish. This biofinish is used to develop a new ...protective, self-healing and decorative biotreatment for wood. In order to understand and control biofinish formation on oil treated wood, the occurrence of different Aureobasidium species on various wood surfaces was studied. Phenotypic variability within Aureobasidium strains presented limitations of morphological identification of Aureobasidium species. PCR amplification and Sanger sequencing of ITS and RPB2 were used to identify the culturable Aureobasidium species composition in mould stained wood surfaces with and without a biofinish. The analysed isolates showed that several Aureobasidium species were present and that Aureobasidium melanogenum was predominantly detected, regardless of the presence of a biofinish and the type of substrate. A. melanogenum was detected on wood samples exposed in the Netherlands, Cameroon, South Africa, Australia and Norway. ITS-specific PCR amplification, cloning and sequencing of DNA extracted from biofinish samples confirmed results of the culturing based method: A. melanogenum is predominant within the Aureobasidium population of biofinishes on pine sapwood treated with raw linseed oil and the outdoor placement in the Netherlands.
Taxonomy is a dynamic discipline and name changes of fungi with biotechnological, industrial, or medical importance are often difficult to understand for researchers in the applied field. Species ...belonging to the genera Aspergillus and Penicillium are commonly used or isolated, and inadequate taxonomy or uncertain nomenclature of these genera can therefore lead to tremendous confusion. Misidentification of strains used in biotechnology can be traced back to (1) recent changes in nomenclature, (2) new taxonomic insights, including description of new species, and/or (3) incorrect identifications. Changes in the recent published International Code of Nomenclature for Algae, Fungi and Plants will lead to numerous name changes of existing Aspergillus and Penicillium species and an overview of the current names of biotechnological important species is given. Furthermore, in (biotechnological) literature old and invalid names are still used, such as Aspergillus awamori, A. foetidus, A. kawachii, Talaromyces emersonii, Acremonium cellulolyticus, and Penicillium funiculosum. An overview of these and other species with their correct names is presented. Furthermore, the biotechnologically important species Talaromyces thermophilus is here combined in Thermomyces as Th. dupontii. The importance of Aspergillus, Penicillium, and related genera is also illustrated by the high number of undertaken genome sequencing projects. A number of these strains are incorrectly identified or atypical strains are selected for these projects. Recommendations for correct strain selection are given here. Phylogenetic analysis shows a close relationship between the genome-sequenced strains of Aspergillus, Penicillium, and Monascus. Talaromyces stipitatus and T. marneffei (syn. Penicillium marneffei) are closely related to Thermomyces lanuginosus and Th. dupontii (syn. Talaromyces thermophilus), and these species appear to be distantly related to Aspergillus and Penicillium. In the last part of this review, an overview of heterothallic reproduction in Aspergillus and Penicillium is given. The new insights in the taxonomy of Aspergillus, Penicillium, and related genera will help to interpret the results generated with comparative genomics studies or other studies dealing with evolution of, for example, enzymes, mating-type loci, virulence genes, and secondary metabolite biosynthetic gene clusters.
Aspergillus species are emerging causative agents of non-dermatophyte mold onychomycosis. In this study, 48 Aspergillus isolates were obtained from patients with onychomycosis in Mashhad, Iran, ...during 2015-2018. The aim is to identify the Aspergillus isolates to the species level by using partial calmodulin and beta-tubulin gene sequencing and MALDI-TOF MS, and to evaluate their in vitro susceptibility to ten antifungal drugs: terbinafine, itraconazole, voriconazole, posaconazole, ravuconazole, isavuconazole, caspofungin, micafungin, anidulafungin and amphotericin B according to CLSI M38-A3. Our results indicate that A.flavus (n = 38, 79%) is the most common Aspergillus species causing onychomycosis in Mashhad, Iran. Other detected species were A. terreus (n = 3), A. tubingensis (n = 2), A. niger (n = 1), A. welwitschiae (n = 1), A. minisclerotigenes (n = 1), A. citrinoterreus (n = 1) and A. ochraceus (n = 1). Aspergillus flavus, A. terreus and A. niger isolates were correctly identified at the species level by MALDI-TOF MS, while all cryptic species were misidentified. In conclusion, A. flavus is the predominant Aspergillus species causing onychomycosis due to Aspergillus spp. in Mashhad, Iran. MALDI-TOF MS holds promise as a fast and accurate identification tool, particularly for common Aspergillus species. It is important that the current database of reference spectra, representing different Aspergillus species is expanded to increase the precision of the species-level identification. Terbinafine, posaconazole and echinocandins were in vitro most active against the studies Aspergillus isolates and terbinafine could be the first choice for treatment of onychomycosis due to Aspergillus.
The
Aspergillus
species are main causative agents of various infections such as invasive aspergillosis (IA) in immunocompromised patients and these infections have high mortality rates. In this ...study, we provide insight in the species causing aspergillosis in Iran based on morphology and sequence data. Clinical (
n
= 117) and environmental isolates (
n
= 54) collected during 2010–2016 from University hospitals in Mashhad and Tehran (Iran) were identified both morphologically and molecularly using partial calmodulin (
CaM
) gene sequences. Clinical cases were identified based on EORTC/MSG criteria.
Aspergillus flavus
(
n
= 96, 55%) was the most prevalent species among the clinical and environmental isolates while
A. fumigatus
(
n
= 13, 7.5%) ranked fourth after
A. tubingensis
(
n
= 23, 13%) and
A. welwitchiae
(
n
= 18, 10%). Species such as
A. tubingensis
,
A. welwitschiae
,
A. fumigatus
,
A. sydowii
,
A. neoniger
and
A. terreus
were present in both clinical and environmental samples indicating the possible environmental source of infections. Interestingly,
A. niger
was isolated only once. Furthermore, 13 other rare and cryptic
Aspergillus
species were detected. Pulmonary and respiratory disorders (
n
= 33), followed by transplantation (
n
= 23), invasive fungal rhinosinusitis (
n
= 14), and haematological malignancies (
n
= 12) were major predisposing factors. According to EORTC/MSG criteria, there were 43 probable cases identified followed by 36 cases for each of proven and possible ones. Correct molecular identification will be useful for further epidemiological studies.
During a previous study on microfungi associated with clematis roots, Penicillium-like fungi were isolated and identified based on morphology. In this study, we subjected those strains to a detailed ...examination which led to the proposal of two taxonomic novelties, named Rasamsonia chlamydospora and Talaromyces clematidis. The first taxon is characterized by rough-walled mycelium, acerose to flask shaped phialides, cylindrical conidia and by production of chlamydospore-like structures. The four-loci-based phylogeny analysis delineated the taxon as a taxonomic novelty in Rasamsonia. Talaromyces clematidis is characterized by restricted growth on Czapek yeast extract agar, dichloran 18% glycerol agar and yeast extract sucrose agar, and production of yellow ascomata on oatmeal agar. Phylogenetic analyses placed this taxon as a taxonomic novelty in Talaromyces sect. Bacillispori. Both taxa are introduced here with detailed descriptions, photoplates and information on their phylogenetic relationship with related species.
Summary
Fungi colonize habitats by means of spores. These cells are stress‐resistant compared with growing fungal cells. Fungal conidia, asexual spores, formed by cosmopolitan fungal genera like ...Penicillium, Aspergillus and Peacilomyces are dispersed by air. They are present in places where food products are stored and as a result, they cause food spoilage. Here, we determined the heterogeneity of heat resistance of conidia between and within strains of Paecilomyces variotii, a spoiler of foods such as margarine, fruit juices, canned fruits and non‐carbonized sodas. Out of 108 strains, 31 isolates showed a conidial survival >10% after a 10‐min‐heat treatment at 59°C. Three strains with different conidial heat resistance were selected for further phenotyping. Conidia of DTO 212‐C5 and DTO 032‐I3 showed 0.3% and 2.6% survival in the screening respectively, while survival of DTO 217‐A2 conidia was >10%. The decimal reduction times of these strains at 60°C (D60 value) were 3.7 ± 0.08, 5.5 ± 0.35 and 22.9 ± 2.00 min respectively. Further in‐depth analysis revealed that the three strains showed differences in morphology, spore size distributions, compatible solute compositions and growth under salt stress. Conidia of DTO 217‐A2 are the most heat‐resistant reported so far. The ecological consequences of this heterogeneity of resistance, including food spoilage, are discussed.
Some species of Talaromyces secrete large amounts of red pigments. Literature has linked this character to species such as Talaromyces purpurogenus, T. albobiverticillius, T. marneffei, and T. ...minioluteus often under earlier Penicillium names. Isolates identified as T. purpurogenus have been reported to be interesting industrially and they can produce extracellular enzymes and red pigments, but they can also produce mycotoxins such as rubratoxin A and B and luteoskyrin. Production of mycotoxins limits the use of isolates of a particular species in biotechnology. Talaromyces atroroseus sp. nov., described in this study, produces the azaphilone biosynthetic families mitorubrins and Monascus pigments without any production of mycotoxins. Within the red pigment producing clade, T. atroroseus resolved in a distinct clade separate from all the other species in multigene phylogenies (ITS, β-tubulin and RPB1), which confirm its unique nature. Talaromyces atroroseus resembles T. purpurogenus and T. albobiverticillius in producing red diffusible pigments, but differs from the latter two species by the production of glauconic acid, purpuride and ZG-1494α and by the dull to dark green, thick walled ellipsoidal conidia produced. The type strain of Talaromyces atroroseus is CBS 133442.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
Aspergillus fumigatus is a major fungal pathogen of humans but its two closest relatives, Aspergillus fischeri and Aspergillus oerlinghausenensis, are not. Steenwyk et al. examined ...whether...
Abstract
Aspergillus fumigatus is a major human pathogen. In contrast, Aspergillus fischeri and the recently described Aspergillus oerlinghausenensis, the two species most closely related to A. fumigatus, are not known to be pathogenic. Some of the genetic determinants of virulence (or “cards of virulence”) that A. fumigatus possesses are secondary metabolites that impair the host immune system, protect from host immune cell attacks, or acquire key nutrients. To examine whether secondary metabolism-associated cards of virulence vary between these species, we conducted extensive genomic and secondary metabolite profiling analyses of multiple A. fumigatus, one A. oerlinghausenensis, and multiple A. fischeri strains. We identified two cards of virulence (gliotoxin and fumitremorgin) shared by all three species and three cards of virulence (trypacidin, pseurotin, and fumagillin) that are variable. For example, we found that all species and strains examined biosynthesized gliotoxin, which is known to contribute to virulence, consistent with the conservation of the gliotoxin biosynthetic gene cluster (BGC) across genomes. For other secondary metabolites, such as fumitremorgin, a modulator of host biology, we found that all species produced the metabolite but that there was strain heterogeneity in its production within species. Finally, species differed in their biosynthesis of fumagillin and pseurotin, both contributors to host tissue damage during invasive aspergillosis. A. fumigatus biosynthesized fumagillin and pseurotin, while A. oerlinghausenensis biosynthesized fumagillin and A. fischeri biosynthesized neither. These biochemical differences were reflected in sequence divergence of the intertwined fumagillin/pseurotin BGCs across genomes. These results delineate the similarities and differences in secondary metabolism-associated cards of virulence between a major fungal pathogen and its nonpathogenic closest relatives, shedding light onto the genetic and phenotypic changes associated with the evolution of fungal pathogenicity.
Abstract
Paecilomyces lilacinus was described more than a century ago and is a commonly occurring fungus in soil. However, in the last decade this fungus has been increasingly found as the causal ...agent of infections in man and other vertebrates. Most cases of disease are described from patients with compromised immune systems or intraocular lens implants. In this study, we compared clinical isolates with strains isolated from soil, insects and nematodes using 18S rRNA gene, internal transcribed spacer (ITS) and partial translation elongation factor 1-α (TEF) sequences. Our data show that P. lilacinus is not related to Paecilomyces, represented by the well-known thermophilic and often pathogenic Paecilomyces variotii. The new genus name Purpureocillium is proposed for P. lilacinus and the new combination Purpureocillium lilacinum is made here. Furthermore, the examined Purpureocillium lilacinum isolated grouped in two clades based on ITS and partial TEF sequences. The ITS and TEF sequences of the Purpureocillium lilacinum isolates used for biocontrol of nematode pests are identical to those causing infections in (immunocompromised) humans. The use of high concentrations of Purpureocillium lilacinum spores for biocontrol poses a health risk in immunocompromised humans and more research is needed to determine the pathogenicity factors of Purpureocillium lilacinum.
Aspergilli known as black- and white-koji molds which are used for awamori, shochu, makgeolli and other food and beverage fermentations, are reported in the literature as A. luchuensis, A. awamori, ...A. kawachii, or A. acidus. In order to elucidate the taxonomic position of these species, available ex-type cultures were compared based on morphology and molecular characters. A. luchuensis, A. kawachii and A. acidus showed the same banding patterns in RAPD, and the three species had the same rDNA-ITS, β-tubulin and calmodulin sequences and these differed from those of the closely related A. niger and A. tubingensis. Morphologically, the three species are not significantly different from each other or from A. niger and A. tubingensis. It is concluded that A. luchuensis, A. kawachii and A. acidus are the same species, and A. luchuensis is selected as the correct name based on priority. Strains of A. awamori which are stored in National Research Institute of Brewing in Japan, represent A. niger (n = 14) and A. luchuensis (n = 6). The neotype of A. awamori (CBS 557.65 = NRRL 4948) does not originate from awamori fermentation and it is shown to be identical with the unknown taxon Aspergillus welwitschiae. Extrolite analysis of strains of A. luchuensis showed that they do not produce mycotoxins and therefore can be considered safe for food and beverage fermentations. A. luchuensis is also frequently isolated from meju and nuruk in Korea and Puerh tea in China and the species is probably common in the fermentation environment of East Asia. A re-description of A. luchuensis is provided because the incomplete data in the original literature.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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