Aspergillus Section Research Articles

Re-identification of Strains from Aspergillus Section Aspergillus and Description of Three Unrecorded Species from Korea

The section Aspergillus includes xerophilic fungi that are economically significant and broadly distributed in natural settings as well as human habitats and are recognized for their sustenance on substrates with low water activity. Accurate identification of fungal species is essential for any reliable advances in mycological research. In this study, 108 strains from the section Aspergillus, originating from Korea and conserved at the Korean Agricultural Culture Collection, were subjected to re-identification using a combined dataset that included partial sequences of β-tubulin (BenA), Calmodulin (CaM), and RNA polymerase II second largest subunit (RPB2) genes, along with their morphological characteristics. We confirmed the presence of 12 species among the 108 strains originally isolated from Korea. Of them, nine species have been formerly reported in Korea (Aspergillus chevalieri, Aspergillus cibarius, Aspergillus cumulatus, Aspergillus glaucus, Aspergillus montevidensis, Aspergillus proliferans, Aspergillus pseudoglaucus, Aspergillus ruber, and Aspergillus tonophilus), and 3 species (Aspergillus aurantiacoflavus, Aspergillus intermedius, and Aspergillus niveoglaucus) were found to be previously unreported to be isolated from Korea. Here, the detailed characteristic features of these three unexplored species are presented, including specific morphological traits, genetic variations, and ecological niches in Korea.

Malian Children's Core Gut Mycobiome.

Because data on the fungal gut community structure of African children are scarce, we aimed to describe it by reanalysing rRNA ITS1 and ITS2 metabarcoding data from a study designed to assess the influence of microbiota in malaria susceptibility in Malian children from the Dogon country. More specifically, we aimed to establish the core gut mycobiome and compare the gut fungal community structure of breastfed children, aged 0-2 years, with other age groups. Briefly, DNA was extracted from 296 children's stool samples. Both rRNA ITS1 and ITS2 genomic barcodes were amplified and subjected to Illumina MiSeq sequencing. The ITS2 barcode generated 1,975,320 reads and 532 operational taxonomic units (OTUs), while the ITS1 barcode generated 647,816 reads and 532 OTUs. The alpha diversity was significantly higher by using the ITS1 compared to the ITS2 barcode (p < 0.05); but, regardless of the ITS barcode, we found no significant difference between breastfed children, aged 0-2 years, compared to the other age groups. The core gut mycobiome of the Malian children included Saccharomyces cerevisiae, Candida albicans, Pichia kudriavzevii, Malassezia restricta, Candida tropicalis and Aspergillus section Aspergillus, which were present in at least 50% of the 296 children. Further studies in other African countries are warranted to reach a global view of African children's core gut mycobiome.

Assessment of mycobiota in Thai pigmented rice: Insights into ochratoxin A and citrinin production by Aspergillus and Penicillium species

Pigmented rice has gained interest for its nutritional and health benefits attributed to its bioactive compounds. Despite these advantages, the vulnerability of pigmented rice to mycotoxin contamination poses a major concern. This study examined the mycobiota of seven Thai pigmented rice varieties, with a focus on fungi capable of producing ochratoxin A (OTA) and citrinin. The study analyzed 110 pigmented rice samples and found that the Aspergillus section Aspergillus was predominant (50–82.35%), followed by Penicillium species (12.50–70.59%). One isolate of A. carbonarius from Aspergillus section Nigri (1/112) and two isolates from Aspergillus section Circumdati (2/61)—A. steynii and A. flocculosus—produced OTA. However, none of the Penicillium species produced OTA, though citrinin production was notable in P. citrinum (128/280). The study found that the Black Jasmine rice and Red Jasmine rice varieties were more susceptible to mycotoxin production, while the Luem Pua glutinous rice and Hom Nil rice varieties displayed more resistance to the accumulation of both mycotoxins. These findings should guide targeted strategies to mitigate mycotoxin risks and ensure the safety of pigmented rice in the food chain.

A review of recently introduced Aspergillus, Penicillium, Talaromyces and other Eurotiales species.

The order Eurotiales is diverse and includes species that impact our daily lives in many ways. In the past, its taxonomy was difficult due to morphological similarities, which made accurate identification of species difficult. This situation improved and stabilised with recent taxonomic and nomenclatural revisions that modernised Aspergillus, Penicillium and Talaromyces. This was mainly due to the availability of curated accepted species lists and the publication of comprehensive DNA sequence reference datasets. This has also led to a sharp increase in the number of new species described each year with the accepted species lists in turn also needing regular updates. The focus of this study was to review the 160 species described between the last list of accepted species published in 2020 until 31 December 2022. To review these species, single-gene phylogenies were constructed and GCPSR (Genealogical Concordance Phylogenetic Species Recognition) was applied. Multi-gene phylogenetic analyses were performed to further determine the relationships of the newly introduced species. As a result, we accepted 133 species (37 Aspergillus, two Paecilomyces, 59 Penicillium, two Rasamsonia, 32 Talaromyces and one Xerochrysium), synonymised 22, classified four as doubtful and created a new combination for Paraxerochrysium coryli, which is classified in Xerochrysium. This brings the number of accepted species to 453 for Aspergillus, 12 for Paecilomyces, 535 for Penicillium, 14 for Rasamsonia, 203 for Talaromyces and four for Xerochrysium. We accept the newly introduced section Tenues (in Talaromyces), and series Hainanici (in Aspergillus sect. Cavernicolarum) and Vascosobrinhoana (in Penicillium sect. Citrina). In addition, we validate the invalidly described species Aspergillus annui and A. saccharicola, and series Annuorum (in Aspergillus sect. Flavi), introduce a new combination for Dichlaena lentisci (type of the genus) and place it in a new section in Aspergillus subgenus Circumdati, provide an updated description for Rasamsonia oblata, and list excluded and recently synonymised species that were previously accepted. This study represents an important update of the accepted species lists in Eurotiales. Taxonomic novelties: New sections: Aspergillus section Dichlaena Visagie, Kocsubé & Houbraken. New series: Aspergillus series Annuorum J.J. Silva, B.T. Iamanaka, Frisvad. New species: Aspergillus annui J.J. Silva, M.H.P. Fungaro, Frisvad, M.H. Taniwaki & B.T. Iamanaka; Aspergillus saccharicola J.J. Silva, Frisvad, M.H.P. Fungaro, M.H. Taniwaki & B.T. Iamanaka. New combinations: Aspergillus lentisci (Durieu & Mont.) Visagie, Malloch, L. Kriegsteiner, Samson & Houbraken; Xerochrysium coryli (Crous & Decock) Visagie & Houbraken. Citation: Visagie CM, Yilmaz N, Kocsubé S, Frisvad JC, Hubka V, Samson RA, Houbraken J (2024). A review of recently introduced Aspergillus, Penicillium, Talaromyces and other Eurotiales species. Studies in Mycology 107: 1-66. doi: 10.3114/sim.2024.107.01.

Identification of closely related species in Aspergillus through Analysis of Whole-Genome.

The challenge of discriminating closely related species persists, notably within clinical diagnostic laboratories for invasive aspergillosis (IA)-related species and food contamination microorganisms with toxin-producing potential. We employed Analysis of the whole-GEnome (AGE) to address the challenges of closely related species within the genus Aspergillus and developed a rapid detection method. First, reliable whole genome data for 77 Aspergillus species were downloaded from the database, and through bioinformatic analysis, specific targets for each species were identified. Subsequently, sequencing was employed to validate these specific targets. Additionally, we developed an on-site detection method targeting a specific target using a genome editing system. Our results indicate that AGE has successfully achieved reliable identification of all IA-related species (Aspergillus fumigatus, Aspergillus niger, Aspergillus nidulans, Aspergillus flavus, and Aspergillus terreus) and three well-known species (A. flavus, Aspergillus parasiticus, and Aspergillus oryzae) within the Aspergillus section. Flavi and AGE have provided species-level-specific targets for 77 species within the genus Aspergillus. Based on these reference targets, the sequencing results targeting specific targets substantiate the efficacy of distinguishing the focal species from its closely related species. Notably, the amalgamation of room-temperature amplification and genome editing techniques demonstrates the capacity for rapid and accurate identification of genomic DNA samples at a concentration as low as 0.1 ng/μl within a concise 30-min timeframe. Importantly, this methodology circumvents the reliance on large specialized instrumentation by presenting a singular tube operational modality and allowing for visualized result assessment. These advancements aptly meet the exigencies of on-site detection requirements for the specified species, facilitating prompt diagnosis and food quality monitoring. Moreover, as an identification method based on species-specific genomic sequences, AGE shows promising potential as an effective tool for epidemiological research and species classification.

Comprehensive assessment of occupational exposure to microbial contamination in waste sorting facilities from Norway.

It is of upmost importance to contribute to fill the knowledge gap concerning the characterization of the occupational exposure to microbial agents in the waste sorting setting (automated and manual sorting). This study intends to apply a comprehensive field sampling and laboratory protocol (culture based-methods and molecular tools), assess fungal azole resistance, as well as to elucidate on potential exposure related health effects (cytotoxicity analyses). Skin-biota samples (eSwabs) were performed on workers and controls to identify other exposure routes. In personal filter samples the guidelines in one automated industry surpassed the guidelines for fungi. Seasonal influence on viable microbial contamination including fungi with reduced susceptibility to the tested azoles was observed, besides the observed reduced susceptibility of pathogens of critical priority (Mucorales and Fusarium sp.). Aspergillus sections with potential toxigenic effect and with clinical relevance were also detected in all the sampling methods. The results regarding skin-biota in both controls´ and workers´ hands claim attention for the possible exposure due to hand to face/mouth contact. This study allowed concluding that working in automated and manual waste sorting plants imply high exposure to microbial agents.

Secondary Metabolites from the Genus Eurotium and Their Biological Activities.

Eurotium is the teleomorph genus associated with the section Aspergillus. Eurotium comprises approximately 20 species, which are widely distributed in nature and human environments. Eurotium is usually the key microorganism for the fermentation of traditional food, such as Fuzhuan brick tea, Liupao tea, Meju, and Karebushi; thus, Eurotium is an important fungus in the food industry. Eurotium has been extensively studied because it contains a series of interesting, structurally diverse, and biologically important secondary metabolites, including anthraquinones, benzaldehyde derivatives, and indol diketopiperazine alkaloids. These secondary metabolites have shown multiple biological activities, including antioxidative, antimicrobial, cytotoxic, antitumor, insecticidal, antimalarial, and anti-inflammatory activities. This study presents an up-to-date review of the phytochemistry and biological activities of all Eurotium species. This review will provide recent advances on the secondary metabolites and their bioactivities in the genus Eurotium for the first time and serve as a database for future research and drug development from the genus Eurotium.

Spontaneously growing fungi on the surface and processing areas of matured sheep ham and volatile compounds produced

Raw ham is a dried and matured product traditionally made from pork leg, but other animals, such as sheep, can be used. The natural presence of bacteria and fungi in this product influences its characteristics throughout the process. This study analysed the fungal populations present during raw sheep hams' processing. Two types of products were developed: without and with the addition of seasonings. Mycological analyses were carried out from the ingredients, seasonings, facilities air, as well as on the surfaces of the hams and the air in the chamber throughout the maturation period (0, 45, 90, and 180 days) using 18 % dichloran glycerol agar and the data were submitted to Principal Component Analysis. Volatile compounds were evaluated at the end of the sheep ham manufacturing process through a gas chromatograph coupled to a mass spectrometer. At 45 days of aging, a more remarkable similarity was observed between the fungi present on the non-seasoned hams and those in the ripening chamber’s air, while the seasoned hams showed a more evident relation with those fungi present in the spices. With time, the fungi in the air of the ripening chamber started to be influenced by Aspergillus ser. Aspergillus and Aspergillus ser. Rubri already installed in the seasoned hams at 45 days, and then it probably dispersed the non-seasoned ones due to the airborne spores, becoming the most prevalent in both treatments at 90 days. At the end of ripening, the mycobiota of both raw hams was composed mainly by xerophilic species of Aspergillus section Aspergillus. The total fungal count was 5.78 log CFU/cm2 for the non-seasoned and 7.19 log CFU/cm2 for the seasoned ones. A potentially ochratoxigenic Aspergillus ser. Circumdati was detected at the end of aging in raw, unseasoned hams. In conclusion, seasoning directly influences the species developing on the surface of seasoned hams throughout the ripening process, and indirectly affects the mycobiota of the non-seasoned hams when sharing the same ripening chamber. The presence of fungi in the matured sheep ham seems to contribute to the formation of volatile compounds, which are related to the sensory quality of these products.

Soil Aspergillus Species, Pathogenicity and Control Perspectives.

Five Aspergillus sections have members that are established agricultural pests and producers of different metabolites, threatening global food safety. Most of these pathogenic Aspergillus species have been isolated from almost all major biomes. The soil remains the primary habitat for most of these cryptic fungi. This review explored some of the ecological attributes that have contributed immensely to the success of the pathogenicity of some members of the genus Aspergillus over time. Hence, the virulence factors of the genus Aspergillus, their ecology and others were reviewed. Furthermore, some biological control techniques were recommended. Pathogenic effects of Aspergillus species are entirely accidental; therefore, the virulence evolution prediction model in such species becomes a challenge, unlike their obligate parasite counterparts. In all, differences in virulence among organisms involved both conserved and species-specific genetic factors. If the impacts of climate change continue, new cryptic Aspergillus species will emerge and mycotoxin contamination risks will increase in all ecosystems, as these species can metabolically adjust to nutritional and biophysical challenges. As most of their gene clusters are silent, fungi continue to be a source of underexplored bioactive compounds. The World Soil Charter recognizes the relevance of soil biodiversity in supporting healthy soil functions. The question of how a balance may be struck between supporting healthy soil biodiversity and the control of toxic fungi species in the field to ensure food security is therefore pertinent. Numerous advanced strategies and biocontrol methods so far remain the most environmentally sustainable solution to the control of toxigenic fungi in the field.

Effect of different storage conditions on the stability and safety of almonds.

Almond production in Portugal is of great importance for the economy of their main producing areas. However, the contamination of these nut fruits with fungi and mycotoxins poses a significant risk to food safety and security. This work intended to evaluate the influence of storage conditions on the microbial and mycotoxin stability and safety of almonds throughout long-term storage. Two almond varieties-Lauranne and Guara-were submitted to three different storage conditions, namely, 4°C with noncontrolled relative humidity (RH), 60% RH at 25°C, and 70% RH at 25°C, for a storage period of 9 months. Samples were collected after 0, 3, 6, and 9 months of storage and analyzed for microbial loads (aerobic mesophiles, yeasts, and molds), mold incidence and diversity, and mycotoxin contamination. In total, 26 species were identified belonging to 6 genera: Aspergillus, Cladosporium, Fusarium, Penicillium, Paecilomyces, and Talaromyces. For the variety Guara, mycotoxins related to Aspergillus sect. Flavi, such as aflatoxins, averufin, versicolorin C, and norsolorinic acid, were detected only after 9 months of storage at 70% and 60% RH. Penicillium mycotoxins, such as quinolactacin A and roquefortine C, were also detected. For the variety Lauranne, Penicillium mycotoxins were detected, such as citrinin, quinolactacins A and B, roquefortines C and D, cyclopenin, cyclopenol, penitrem A, viridicatin, and viridicatol. Mycotoxins related to Aspergillus, such as aspulvinone E, flavoglaucin, paspalin, asperglaucide, asperphenamate, cyclo(L-Pro-L-Tyr), and cyclo(L-Pro-L-Val), were also detected. PRACTICAL APPLICATION: (Optional, for JFS Research Articles ONLY) The quality of almonds depends on the storage period and the RH and temperature at which they are stored. Storage of almonds at 60% RH at 25°C is a good storage condition to maintain the stability and safety of nuts in terms of microbial and mycotoxin contaminations.

Diversity and Distribution of Aspergillus fumigatus and Its Related Species in Izu and Ogasawara Islands, Japan.

The taxon Aspergillus section Fumigati comprises several causative agents of aspergillosis. Here, the distribution of Aspergillus sect. Fumigati in outdoor environments of Izu and Ogasawara Islands was investigated. Different strains were isolated from soil samples collected from 68 sites on 9 islands (Izu-oshima, Toshima, Shikinejima, Kozushima, Miyakejima, Hachijojima, Mukojima, Chichijima, and Hahajima), including different landscapes, and identified using morphological characteristics and calmodulin (CaM) sequences. Seven Aspergillus sect. Fumigati species were identified. The occurrence frequency of Aspergillus fumigatus was higher in forest sites on the islands, except for Ogasawara Islands, whereas that of species other than A. fumigatus was higher in bare land and grassland sites on all islands. The occurrence frequency of A. fumigatus was more than 50% on islands between Izu-oshima and Toshima, decreased on islands between Shikinejima and Hachijojima, and was zero on Ogasawara Islands. Considering other Aspergillus species, Aspergillus felis showed high occurrence frequency on islands between Izu-oshima and Shikinejima, Aspergillus pseudoviridinutans on islands between Kozushima and Hachijojima, and Aspergillus udagawae on Ogasawara Islands. At two study sites (grassland and forest sites), the soil was sampled throughout the year to evaluate whether the occurrence frequency of each fungal species was affected by sampling season. At the grassland site, A. pseudoviridinutans was isolated at more than 90% frequency, regardless of the sampling season. A. fumigatus occurrence frequency at the forest site ranged from 0% to 60% and greatly varied among sampling seasons. Thus, differences in island location and landscape affected the distribution of Aspergillus sect. Fumigati.

Postharvest Rot of Pomegranate Fruit in Southern Italy: Characterization of the Main Pathogens.

Pomegranate (Punica granatum L.) is an emerging crop in Italy and particularly in southern regions, such as Apulia, Basilicata, and Sicily, due to favorable climatic conditions. The crop is affected by several pathogenic fungi, primarily in the field, but also during postharvest phases. The most important postharvest fungal diseases in pomegranate are gray and blue molds, black heart and black spot, anthracnose, dry rot, and various soft rots. The limited number of fungicides allowed for treatment in the field and the lack of postharvest fungicides make it difficult to control latent, quiescent, and incipient fungal infections. Symptomatic pomegranates from southern Italy were sampled and isolated fungi were morphologically and molecularly characterized. The data obtained revealed that various species of Penicillium sensu lato (including Talaromyces genus), Alternaria spp., Coniella granati, and Botrytis cinerea were the principal etiological agents of postharvest pomegranate fruit diseases; other relevant pathogens, although less represented, were ascribable to Aspergillus sect. nigri, Colletotrichum acutatum sensu stricto, and Cytospora punicae. About two thirds of the isolated pathogens were responsible for latent infections. The results obtained may be useful in planning phytosanitary control strategies from the field to storage, so as to reduce yield losses.

Toxic Indoor Air Is a Potential Risk of Causing Immuno Suppression and Morbidity-A Pilot Study.

We aimed to establish an etiology-based connection between the symptoms experienced by the occupants of a workplace and the presence in the building of toxic dampness microbiota. The occupants (5/6) underwent a medical examination and urine samples (2/6) were analyzed by LC-MS/MS for mycotoxins at two time-points. The magnitude of inhaled water was estimated. Building-derived bacteria and fungi were identified and assessed for toxicity. Separate cytotoxicity tests using human THP-1 macrophages were performed from the office’s indoor air water condensates. Office-derived indoor water samples (n = 4/4) were toxic to human THP-1 macrophages. Penicillium, Acremonium sensu lato, Aspergillus ochraceus group and Aspergillus section Aspergillus grew from the building material samples. These colonies were toxic in boar sperm tests (n = 11/32); four were toxic to BHK-21 cells. Mycophenolic acid, which is a potential immunosuppressant, was detected in the initial and follow-up urine samples of (2/2) office workers who did not take immunosuppressive drugs. Their urinary mycotoxin profiles differed from household and unrelated controls. Our study suggests that the presence of mycotoxins in indoor air is linked to the morbidity of the occupants. The cytotoxicity test of the indoor air condensate is a promising tool for risk assessment in moisture-damaged buildings.

Morphological and molecular features of stain fungi infecting rubberwood (Hevea brasiliensis)

Abstract. Nandika D, Arinana, Salman ABA, Putri JY. 2021. Morphological and molecular features of stain fungi infecting rubberwood (Hevea brasiliensis). Biodiversitas 22: 5408-5416. In the southeast Asia region, particularly Indonesia, Thailand, and Malaysia, rubberwood (Hevea brasiliensis Muell. Arg.) has been widely used as a raw material in various industries particularly furniture manufacturing. However, rubberwood is highly susceptible to fungal attack due to its lack of heartwood formation. A laboratory study was conducted to investigate the morphological and molecular features of stain fungi infecting rubberwood. A total of five isolates of stain fungi belonging to three genera were identified based on internal transcribed spacer (ITS) and morphological features. All isolates belong to Order Eurotiales with each genus being Paecilomyces, Aspergillus, and Penicillium. The highest growth rate on wood samples was shown by Aspergillus chevalieri section Aspergillus and Paecilomyces maximus or P. formosus with values of 86.57% and 86.22%, respectively. All of the stain fungi genera caused varied level of discoloration on wood samples with dark grayish and very dark grayish as the more frequent color found. Quantitatively, the highest discoloration was shown by A. chevalieri section Aspergillus (?E = 27.60) and P. maximus or P. formosus (?E = 16.69). These species can be considered as newly stain fungi recorded infecting rubberwood in Indonesia. In addition, discoloration caused by these two stain fungi was the worst.

The accuracy and clinical impact of the morphological identification of Aspergillus species in the age of cryptic species: A single-centre study.

Aspergillus spp. is identified morphologically without antifungal susceptibility tests (ASTs) in most clinical laboratories. The aim of this study was to examine the clinical impact of the morphological identification of Aspergillus spp. to ensure the adequate clinical management of Aspergillus infections. Aspergillus isolates (n=126) from distinct antifungal treatment-naïve patients with aspergillosis were first identified morphologically, followed by species-level identification via DNA sequencing. An AST for itraconazole (ITC) and voriconazole (VRC) was performed on each Aspergillus isolate. Based on the genetic test results, morphology-based identification was accurate for >95% of the isolates at the species sensu lato level although the test concordance of Aspergillus spp. with low detection rates was low. The rates of cryptic species were found to be 1.2% among the isolates of A.fumigatus complex and 96.8% in the A.niger complex. Cryptic species with lower susceptibilities to antifungal drugs than sensu stricto species among the same Aspergillus section were as follows: The A.lentulus (n=1) isolates had low susceptibilities to azoles among the A.fumigatus complex species (n=86), and A.tubingensis isolates (n=18) exhibited lower susceptibility to azoles among the A.niger complex species (n=31). Diagnostic accuracy was high at the A.fumigatus and A.niger complex level. However, in the presence of cryptic species, a solely morphological identification was insufficient. Particularly, ITC and VRC might be inappropriate for aspergillosis treatment when the A.niger complex is identified morphologically because it is possible that the Aspergillus isolate is A.tubingensis.

Aflatoxins are natural scavengers of reactive oxygen species

The role of aflatoxins (AFs) in the biology of producing strains, Aspergillus sect. Flavi, is still a matter of debate. Over recent years, research has pointed to how environmental factors altering the redox balance in the fungal cell can switch on the synthesis of AF. Notably, it has been known for decades that oxidants promote AF synthesis. More recent evidence has indicated that AF synthesis is controlled at the transcriptional level: reactive species that accumulate in fungal cells in the stationary growth phase modulate the expression of aflR, the main regulator of AF synthesis—through the oxidative stress related transcription factor AP-1. Thus, AFs are largely synthesized and secreted when (i) the fungus has exploited most nutritional resources; (ii) the hyphal density is high; and (iii) reactive species are abundant in the environment. In this study, we show that AFs efficiently scavenge peroxides and extend the lifespan of E. coli grown under oxidative stress conditions. We hypothesize a novel role for AF as an antioxidant and suggest its biological purpose is to extend the lifespan of AFs-producing strains of Aspergillus sect. Flavi under highly oxidizing conditions such as when substrate resources are depleted, or within a host.

An exploratory MALDI-TOF MS library based on SARAMIS superspectra for rapid identification of Aspergillus section Nigri.

Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) is a broadly used technique for identification and typing of microorganisms. However, its application to filamentous fungi has been delayed. The objective of this study was to establish a data library for rapid identification of the genus Aspergillus sect. Nigri using MALDI-TOF MS. With respect to sample preparation, we compared the utility of using mature mycelia, including conidial structures, to accumulate a wider range of proteins versus the conventional method relying on young hyphae. Mass spectral datasets obtained for 61 strains of 17 species were subjected to cluster analysis and compared with a phylogenetic tree based on calmodulin gene sequences. Specific and frequent mass spectral peaks corresponding to each phylogenetic group were selected (superspectra for the SARAMIS system). Fifteen superspectra representing nine species were ultimately created. The percentage of correct identification for 217 spectra was improved from 36.41% to 86.64% using the revised library. Additionally, 2.76% of the spectra were assigned to candidates that comprised several related species, including the correct species.

Culture Media and Sampling Collection Method for Aspergillus spp. Assessment: Tackling the Gap between Recommendations and the Scientific Evidence

Culturing is still the most widely used method for determining fungal growth. Thus, is important to identify the most suitable culture media to assess Aspergillus spp. The aim of this study was to analyze data obtained from previous studies, aiming at identifying the most suitable culture media (malt extract agar (MEA) or dichloran-glycerol agar (DG18) to assess Aspergillus spp. isolation and growth. This study was conducted by using environmental samples (n = 1153). Most of the active sampling methods (air samples) were impacted directly onto both culture media. As for passive sampling methods, fungi were extracted from environmental matrices inoculated onto both media. Overall, total Aspergillus counts were higher in MEA (n = 617, 53.5%) than in DG18 (n = 536, 46.5%). Regarding Aspergillus sections, significant associations were detected with the media (χ2 (7) = 241.118, p &lt; 0.001), the sampling approach (p &lt; 0.001, 95% CI = (0.3 × 10−4), and the indoor environment (p &lt; 0.001, 95% CI = (0.3 × 10−4)). As such, sampling approach and the culture media should be accurately selected when dealing with Aspergillus spp. exposure assessment.

Aspergillus tubingensis Is a Pre-Emergent Pathogen of Date Palm Seedlings

Many diseases of date palm are known. However, pathogens that might affect seed germination and seedling emergence from soil are poorly studied, perhaps because date palm cultivars are propagated vegetatively. Here, we first determined the effects of date seed fungi on the germination and emergence of 600 seeds overall (i.e., 200 of each of three cultivars: ‘Thoory’, ‘Halawi’, and ‘Barhi’). In each cultivar, 100 seeds were from Saudi Arabia (part of the native range), and 100 were from the southwestern USA (where the date palm was introduced around 1765). Just four fungal genera (i.e., Alternaria, Aspergillus, Chaetomium, and Penicillium) were isolated from the surface-sterilized date seeds. Aspergillus isolates all belonged to Aspergillus sect. Nigri; collectively they were in the highest relative abundance at 39%, and significantly more common in Saudi Arabian seeds than in American seeds. Aspergillus reduced seed germination and also reduced emergence when germinated and non-germinated seeds were planted in potting mix in a greenhouse. In contrast, Penicillium species were more common in American than in Saudi seeds; Penicillium did not affect germination, although it did have a positive effect on seedling emergence. In a second experiment with 17 seeds of the ‘Halawi’ cultivar, fungus-free seeds were either inoculated with isolates of Aspergillus sect. Nigri or not, and then planted. Controls emerged whereas Aspergillus-inoculated seeds did not. Finally, a third experiment was conducted with Aspergillus tubingensis Mosseray, a sect. Nigri member, as sole inoculum of 100 ‘Halawi’ seeds versus 100 uninoculated controls. Aspergillus tubingensis exerted the same pathogenic effects on germinating and emerging seedlings as the isolates identified only to Aspergillus sect. Nigri. Aspergillus tubingensis is thus a previously unreported, seedborne pathogen affecting date palm seedlings. Our findings also suggest that A. tubingensis may be more common in seeds in the host’s native range than in its introduced range.

Assessment of Children’s Potential Exposure to Bioburden in Indoor Environments

The exposure to particles and bioaerosols has been associated with the increase in health effects in children. The objective of this study was to assess the indoor exposure to bioburden in the indoor microenvironments more frequented by children. Air particulate matter (PM) and settled dust were sampled in 33 dwellings and four schools with a medium volume sampler and with a passive method using electrostatic dust collectors (EDC), respectively. Settled dust collected by EDC was analyzed by culture-based methods (including azole resistance profile) and using qPCR. Results showed that the PM2.5 and PM10 concentrations in classrooms (31.15 μg/m3 and 57.83 μg/m3, respectively) were higher than in homes (15.26 μg/m3 and 18.95 μg/m3, respectively) and highly exceeded the limit values established by the Portuguese legislation for indoor air quality. The fungal species most commonly found in bedrooms was Penicillium sp. (91.79%), whereas, in living rooms, it was Rhizopus sp. (37.95%). Aspergillus sections with toxigenic potential were found in bedrooms and living rooms and were able to grow on VOR. Although not correlated with PM, EDC provided information regarding the bioburden. Future studies, applying EDC coupled with PM assessment, should be implemented to allow for a long-term integrated sample of organic dust.