<Emphasis Type="Italic">Alternaria</Emphasis> toxins in South African sunflower seeds: cooperative study

Sunflower seed samples (N = 80) from different sunflower cultivars originating from different localities in South Africa were analyzed for 15 toxins produced by fungi of the genus Alternaria by means of a simple one-step extraction dilute-and-shoot HPLC-MS/MS approach. References for valine-tenuazonic acid (Val-TeA), altenusin (ALTS), and altenuisol (ALTSOH) were isolated from fungal culture extracts and spectroscopically characterized. Additionally, valine-tenuazonic acid was tested regarding its cytotoxicity in comparison with tenuazonic acid (TeA) and showed less activity on HT-29 cells. Furthermore, alternariol monomethyl ether-3-O-ß-D-glucoside (AME-3G) was produced by fermentation of alternariol monomethyl ether (AME) with the fungus Rhizopus oryzae. The seed samples were analyzed both with and without hulls. The method covers the AAL toxins TA₁ and TA₂, altenuene (ALT) and iso-altenuene (iso-ALT), altenuisol, altenusin, altertoxin I (ATX-I) and altertoxin II (ATX-II), alternariol (AOH) and alternariol monomethyl ether, alternariol monomethyl ether-3-O-ß-D-glucoside, tenuazonic acid, allo-tenuazonic acid (allo-TeA) and valine-tenuazonic acid, and tentoxin (TEN). More than 80% of the samples were positive for one or more analytes above the respective limit of detection (0.2–23 μg/kg). Alternariol, its monomethyl ether, tentoxin, tenuazonic acid, altenuisol, and valine-tenuazonic acid were found in quantifiable amounts. The highest prevalences were found for tentoxin (73% positive, mean content 13.2 μg/kg, maximum level 130 ± 0.9 μg/kg) followed by tenuazonic acid (51% positive, mean content 630 μg/kg, maximum level 6300 ± 560 μg/kg). The obtained data were further analyzed statistically to identify quantitative or qualitative relationships between the levels of Alternaria toxin in the samples.     

Natural Occurrence of Alternaria Toxins in Wheat-Based Products and Their Dietary Exposure in China

A total of 181 wheat flour and 142 wheat-based foods including dried noodle, steamed bread and bread collected in China were analyzed for alternariol (AOH), alternariol monomethyl ether (AME), tentoxin (TEN) and tenuazonic acid (TeA) by ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry. TeA was the predominant toxin found in 99.4% wheat flour samples at levels ranging from 1.76 μg/kg to 520 μg/kg. TEN was another Alternaria toxin frequently detected in wheat flour samples (97.2%) at levels between 2.72 μg/kg and 129 μg/kg. AOH and AME were detected in 11 (6.1%) samples at levels ranging from 16.0 μg/kg to 98.7 μg/kg (AOH) and in 165 (91.2%) samples with a range between 0.320 μg/kg and 61.8 μg/kg (AME). AOH was quantified at higher levels than AME with the ratio of AOH/AME ranging from 1.0 to 3.7. Significant linear regressions of correlation in toxin concentrations were observed between AOH and AME, AME and TeA, TEN and TeA, AOH+AME and TeA. At an average and 95th percentile, dietary exposure to AOH and AME in the Chinese general population and different age subgroups exceeded the relevant threshold value of toxicological concern (TTC), with the highest exposure found in children which deserves human health concern. TEN and TeA seem unlikely to be health concerns for the Chinese via wheat-based products but attention should be paid to synergistic or additive effects of TeA with AOH, AME, TEN and a further assessment will be performed once more data on toxicity-guided fractionation of the four toxins are available. It is necessary to conduct a systemic surveillance of Alternaria toxins in raw and processed foods in order to provide the scientific basis for making regulations on these toxins in China.     

Determinación de perfiles de producción de metabolitos secundarios característicos de especies del género Alternaria aisladas de tomate

BackgroundMany Alternaria species have been studied for their ability to produce bioactive secondary metabolites, such as tentoxin (TEN), some of which have toxic properties. The main food contaminant toxins are tenuazonic acid, alternariol (AOH), alternariol monomethyl ether (AME), altenuene, and altertoxins i, ii and iii.AimsTo determine the profiles of secondary metabolites characteristic of Alternaria strains isolated from tomato for their chemotaxonomic classification.MethodsThe profiles of secondary metabolites were determined by HPLC MS.ResultsThe Alternaria isolates obtained from spoiled tomatoes belong, according to their morphological characteristics, to the species groups Alternaria alternata, Alternaria tenuissima and Alternaria arborescens, with A. tenuissima being the most frequent. The most frequent profiles of secondary metabolites belonging to the species groups A. alternata (AOH, AME, TEN), A. tenuissima (AOH, AME, TEN, tenuazonic acid) and A. arborescens (AOH, AME, TEN, tenuazonic acid) were determined, with some isolates of the latter being able to synthesize AAL toxins.ConclusionsSecondary metabolite profiles are a useful tool for the differentiation of small spored Alternaria isolates not easily identifiable by their morphological characteristics.     

Precise determination of the <Emphasis Type="Italic">Alternaria</Emphasis> mycotoxins alternariol and alternariol monomethyl ether in cereal,fruit and vegetable products using stable isotope dilution assays

Cereal, fruit and vegetable products were analyzed for contamination with the Alternaria mycotoxins alternariol (AOH) and alternariol monomethyl ether (AME) using stable isotope dilution assays (SIDAs). Both toxins were practically not detected in cereals and cereal products: AOH—one out of 13 samples at a content of 4.1 μg/kg; AME—two out of 13 samples at contents ranging between 0.2 and 0.6 μg/kg. However, if cereals for animal nutrition were analyzed, much higher values were found: AOH—five out of six samples (13–250 μg/kg); AME—six out of six samples (3–100 μg/kg). This finding may pose a potential problem concerning animal health. AOH and AME were frequently detected in vegetable products: AOH—5 out of 10 samples (2.6–25 μg/kg); AME—6 out of 10 samples (0.1–5 μg/kg). Tomato products were affected, especially. The highest content of AOH (25 μg/kg) and AME (5 μg/kg) were found in triple concentrated tomato paste. Special wines like “Trockenbeerenauslese” or “Spätlese” (affected by noble rot in the vineyard) contained AOH (4/6 samples; 1.2–4.9 μg/kg) and AME (4/6 samples; 0.1–0.3 μg/kg), but the values did not exceed the values of both toxins that were found generally in wines.     

Phylogenetic,toxigenic and virulence profiles of <Emphasis Type="Italic">Alternaria</Emphasis> species causing leaf blight of tomato in Egypt

Species of Alternaria are serious plant pathogens, causing major losses on a wide range of crops. Leaf blight symptoms were observed on tomato leaves, and samples were collected from various regions. Isolation was done from symptomatic tomato leaves, and 15 representatives were selected from a collection of 65 isolates of Alternaria species. The virulence of Alternaria isolates was investigated on detached leaves (DL) and whole plants of tomato cv. Super strain B. A phylogenetic analysis was performed based on three partial gene regions, the glyceraldehyde-3-phosphate dehydrogenase (GAPDH), the RNA polymerase second largest subunit (RPB2) and the Alternaria major allergen gene (Alt a 1). The potentiality of Alternaria isolates to produce toxins was also investigated on the basis of thin-layer chromatography (TLC). Our investigations revealed that Alternaria isolates showed different levels of virulence either on tomato plants or DL. Based on the phylogeny of three genes, Alternaria isolates encompassed two species of small-spored morphospecies: A. alternata (14 isolates) and A. arborescens (single isolate). The produced toxins varied among Alternaria isolates with tenuazonic acid (TeA) being the most abundant mycotoxin produced by most isolates. This study highlighted on other Alternaria species in Egypt that might represent a serious concern for tomato producers as causal agents of leaf blight over other species, i.e. A. solani.     

Effect of heat treatments on stability of altemariol, alternariol monomethyl ether and tenuazonic acid in sunflower flour

A study was carried out to evaluate the effect of heat treatment on the stability of alternariol (AOH), alternariol monomethyl ether (AME) and tenuazonic acid (TeA) in sunflower flour and the effectiveness of this treatment by a biological assay in rats. The concentrations of AOH and AME remained constant during heating at 100°C for up to 90 minutes while TeA concentration decreased with time to 50% after 90 minutes. The most effective treatment in reducing AOH and AME levels was heating at 121°C for 60 minutes. Histopathological evaluation in the biological assay in rats fed withAlternaria toxins showed marked atrophy and fusion of villi in the intestines and liver cell damage; these lesions were less severe in rats fed heat-treated sunflower flour in line with the reduced toxin content. However, a lower weight gain and a noticeable renal damage in rats were produced when they fed decontaminated flour.     

Mycotoxin production by some IndianAlternaria species

A total of seven species ofAlternaria: A. alternata (Fr.) Keissler;A. capsici-annui Savul & Sandu;A. citri Ellis & Pierce;A. porri (Ellis) Clfferi;A. radicina Meler, Drechsler & Eddy;A. tenuissima (Kunze: Pers) Wiltshire andA. tomato (Cooke) Jones were screened on rice culture medium for their ability to elaborate five majorAlternaria mycotoxins viz. tenuazonlc acid (TA), alternariol (AOH), alternariol methyl ether (AME), altenuene (ALT) and altertoxin-l (ATX-I). All the species produced mycotoxins in varying concentrations. A.capsici-annul was recorded as the mycotoxin producer for the first time. ALT byA. citri andA. tomato; ALT, and ATX-I byA. tenuissima; ALT, TA and AME byA. porri and TA byA. radicina are the new additions to the list of mycotoxins produced by the respective species ofAlternaria.     

Absorption and metabolism of the mycotoxins alternariol and alternariol-9-methyl ether in Caco-2 cells in vitro

Alternariol (AOH) and alternariol-9-methyl ether (AME) are major toxins produced by fungi of the genus Alternaria. In order to simulate their in vivo intestinal absorption and metabolism, AOH and AME have been studied in differentiated Caco-2 cells and in the Caco-2 Millicell® system in vitro. AOH was found to be readily conjugated to two glucuronides and one sulfate, whereas AME gave rise to one major glucuronide and one sulfate. Whereas the glucuronides of AOH and AME were sequestered about equally well into the basolateral and the apical compartment, the sulfates of both toxins were preferentially released to the apical side. Unconjugated AOH but not AME aglycone reached the basolateral chamber. The apparent permeability coefficients (P_app values) were calculated for the aglycones as well as total mycotoxin-associated compounds using an initial apical concentration of 20 µmol/l AOH or AME. Based on these P_app values, AOH must be expected to be extensively and rapidly absorbed from the intestinal lumen in vivo and reach the portal blood both as aglycone and as glucuronide and sulfate. In contrast, intestinal absorption of AME appears to be poor and sluggish, with no AME agylcone and only AME conjugates reaching the portal blood.     

Activities of human recombinant cytochrome P450 isoforms and human hepatic microsomes for the hydroxylation ofAlternaria toxins

TheAlternaria toxins alternariol (AOH), alternariol-9-methyl ether (AME), altenuene (ALT) and isoaltenuene (iALT) undergo extensive oxidative metabolism, but the cytochrome P450 (CYP) isoforms responsible for the reported hydroxylation reactions are yet unknown. In the present study, the activities of twelve human CYP isoforms for the hydroxylation of AOH, AME, ALT and iALT at different positions have been determined. The most active monooxygenase for AOH and AME was CYP1A1, and lower activities were observed for CYP1A2, 2C19 and 3A4. Hydroxylation at C-2 of AOH and AME was the preferred reaction of most isoforms. For ALT and iALT, CYP2C19 had the highest activity, followed by 2C9 and 2D6. The dominating metabolite of all active isoforms was the 8-hydroxylated ALT and iALT. The activities of the CYP isoforms are consistent with the pattern of metabolites of theAlternaria toxins obtained with pooled human hepatic microsomes. Based on the activities of the CYP isoforms, a significant extrahepatic hydroxylation must be expectede.g. in the lung and esophagus for AOH and AME, and in the intestine and ovaries for ALT and iALT. As all major hydroxylation products are catechols, the extrahepatic metabolism ofAlternaria toxins may be of toxicological relevance. Presented at the 30^th Mycotoxin Workshop, Utrecht, Netheriands, April 28–30. 2008. Financial support: State of Baden-Württemberg (Research Program “Mycotoxins” as part of the Research Initiative “Food and Health”)     

Natural occurrence of alternariol and alternariol monomethyl ether in soya beans

The natural occurrence of alternariol (AOH) and alternariol monomethyl ether (AME) in soya beans harvested in Argentina was evaluated. Both toxins were simultaneously detected by using HPLC analysis coupled with a solid phase extraction column clean-up. Characteristics of this in-house method such as accuracy, precision and detection and quantification limits were defined by means of recovery test with spiked soya bean samples. Out of 50 soya bean samples, 60% showed contamination with the mycotoxins analyzed; among them, 16% were only contaminated with AOH and 14% just with AME. Fifteen of the positive samples showed co-occurrence of both mycotoxins analyzed. AOH was detected in concentrations ranging from 25 to 211?ng/g, whereas AME was found in concentrations ranging from 62 to 1,153?ng/g. Although a limited number of samples were evaluated, this is the first report on the natural occurrence of Alternaria toxins in soya beans and is relevant from the point of view of animal public health.     

The influence of meteorological parameters on <Emphasis Type="Italic">Alternaria</Emphasis> and <Emphasis Type="Italic">Cladosporium</Emphasis> fungal spore concentrations in Beja (Southern Portugal): preliminary results

Introduction Fungal spores constitute an important fraction of bioaerosols in the atmosphere. Objectives To analyse the content of Alternaria and Cladosporium spores in the atmosphere of Beja and the effect of meteorological conditions on their concentrations. Methodology The daily and hourly data of Alternaria and Cladosporium fungal spores concentration in the atmosphere of Beja were monitored from April 12, 2012 to July 30, 2014, based on the Portuguese Aerobiology Network methodology. The influence of meteorological conditions on the studied types of fungal spore concentrations was assessed through Spearman’s correlation analysis. Results During the study period, 20,741 Alternaria spores and 320,862 Cladosporium spores were counted. In 2013, there were 5,822 Alternaria spores and 123,864 Cladosporium spores. The absolute maximum concentrations of Alternaria and Cladosporium spores were recorded on November 8, 2013, with 211 and 1301 spores/m³, respectively. Temperature, insolation and wind direction parameters showed a positive correlation with Alternaria and Cladosporium spore levels, while relative humidity and precipitation presented a negative correlation, which is statistically significant. Wind speed only showed a statistically significant positive correlation in terms of Alternaria spore levels. Conclusion Alternaria and Cladosporium spores are present in the atmospheric air of Beja throughout the year, with the highest concentration period occurring during spring and autumn. There was a clear effect of meteorological parameters on airborne concentrations of these fungal spores.     

Effect of airborne <Emphasis Type="Italic">Alternaria</Emphasis> conidia,ozone exposure,PM<Subscript>10</Subscript> and weather on emergency visits for asthma in school-age children in Kolkata city,India

Alternaria is one of the important allergenic fungal spores having special role in childhood asthma. Aerodynamic particle of <10 μm diameter (PM₁₀) and ozone exacerbate respiratory conditions including asthma. There is no documentation determining the role of airborne concentration of Alternaria conidia, pollutants like PM₁₀ and ozone and weather on school-age (5–18 years) children causing life-threatening episodes requiring emergency hospitalization for asthma in the megacity of Kolkata, Eastern India. We examined the relationship of daily hospitalization for asthma in school-age children and daily concentration of outdoor Alternaria conidia, ozone, PM₁₀ and weather parameters in the atmosphere of Kolkata during 2010 using nonparametric generalized additive model (GAM). After a baseline survey (2008–2009), asthma hospitalization data for school-age children (based on case history and symptom-medication) were collected from two important city hospitals near study area in 2010. Daily Alternaria concentration was recorded using Burkard volumetric sampler. Its allergenic potential was confirmed by skin reactivity. Ozone and PM₁₀ concentration data were collected from West Bengal Pollution Control Board. The daily time series analyses of data were performed using GAM. There are two peak seasons of asthma hospitalization, one in spring-early summer (end of March to mid April) and other in autumn (mid September–October). In GAM analyses, Alternaria conidia, ozone and PM₁₀ were found to be significant both in spline and LOcal regrESSion smoothing method. Airborne Alternaria conidia, ozone and PM₁₀ in the city of Kolkata are found to have effect on school-age children with asthma and appear responsible for severe attacks leading to hospitalization.     

Production of alternarioi and alternariol monomethyl ether in natural substrates in comparison with semisynthetic culture medium

The comparison In toxins production and growth byAlternarla strains in liquid, solid culture media and natural substrates (rice and sunflower) was evaluated. Ground rice- corn steep liquor medium (GRCS) was the more suitable medium for production of alternariol (AOH) and alternariol monomethyl ether(AME). The maximum levels produced were 676 μg/50ml AOH and 1570/50ml AME. Rice was better than sunflower In supporting toxins production. Different ratios AOH/AME were found according to the substrate evaluated.     

Influence of dietary fibre on plasma and urinary levels of zearalenone and metabolites in swine

The genusAlternaria is responsible for different plant diseases such as tobacco brown spot, tomato blight, and citrus seedling chlorosis but can also be present during storage of grain. The objective of the present paper is to summarize the knowledge concerning regulation of secondary metabolism inAlternaria, particularA alternata (A tenuis). The paper mainly deals with regulation of polyketide biosynthesis, one of the major pathways leading to the biosynthesis of mycotoxins inAlternaria. The mostly studiedAlternaria mycotoxins are dibenzopyrones such as alternariol (AOH) and alternariol monomethyl ether (AME) and altenuene along with the tetramic acid tenuazonic acid. The biosynthesis ofAlternaria mycotoxins has been reviewed by Stinson (12). Most information is available for the biosynthesis of the polyketides AOH / AME while a few biosynthetic studies have been accomplished for tenuazonic acid (11).     

Occurrence of alternariol, alternariol monomethyl ether and tenuazonic acid in Argentinean tomato puree

The occurrence ofAlternaria mycotoxins was investigated in 80 samples of tomato puree processed and sold in Argentina. Alternariol (AOH), alternariol monomethyl ether (AME) and tenuazonic acid (TA) were searched for by liquid chromatography. Thirty-nine of the 80 samples showed mycotoxin contamination. TA was found in 23 samples (39-4021 μg/kg), AOH in 5 samples (187-8756 μg/kg), and AME in 21 samples (84-1734 μg/kg). Co-occurrence of two of these toxins was detected in 10 samples. This is the first report of natural occurrence of AOH, AME and TA in tomato products in Argentina.     

Recalcitrance Assessment of the Agro-industrial Residues from Five <Emphasis Type="Italic">Agave</Emphasis> Species: Ionic Liquid Pretreatment,Saccharification and Structural Characterization

Agave has recently shown its potential as a bioenergy feedstock with promising features such as higher biomass productivity than leading bioenergy feedstock while at the same time being drought-resistant with low water requirements and high sugar to ethanol conversion using ionic liquid (IL) pretreatment. IL pretreatment was studied to develop the first direct side-by-side comparative recalcitrance assessment of the agro-industrial residues from five Agave species [Agave americana (AME), A. angustifolia (ANG), A. fourcroydes (FOU), A. salmiana (SAL), and A. tequilana (TEQ)] using compositional analysis, X-ray diffraction, and the lignin syringyl/guaiacyl subunit ratio (S/G) by pyrolysis molecular beam mass spectrometry (PyMBMS). Prominent calcium oxalate peaks were found only in unpretreated AME, SAL, and TEQ. The S/G ratios of all five unpretreated Agave species were between 1.27 and 1.57 while the IL-pretreated samples were from 1.39 to 1.72. The highest overall sugar production was obtained with IL-pretreated FOU with 492 mg glucose/g biomass and 157 mg xylose/g biomass at 120 °C and 3 h using 1-ethyl-3-methylimidazolium acetate ([C₂C₁Im][OAc]). An estimated theoretical ethanol yield from the studied agro-industrial residues from the five Agave species was in the range of 1060 to 5800 L ethanol/ha/year. These comparison results demonstrate the potential of the Agave spp. as a suitable biofuel feedstock which can be employed within a biorefinery scheme.     

<Emphasis Type="Italic">Alternaria</Emphasis> toxins: DNA strand-breaking activity in mammalian cells<Emphasis Type="Italic">in vitro</Emphasis>

Treatment, for 1 h, of cultured Chinese hamster V79 cells, human liver HepG2 cells, and human colon HT-29 cells with theAlternaria toxins alternariol (AOH) and alternariol methyl ether (AME) caused a concentration-dependent induction of DNA strand breaks at concentrations ranging from 5 to 50 micromolar. After treatment for 24 h, DNA strand breaks were observed in HepG2 but not HT-29 cells. Analysis of the 24 h-incubation media of HT-29 cells showed that both toxins were completely conjugated, whereas 75% were still present as unconjugated compounds in the 24 h-media of HepG2 cells. Lysates of both cell types fortified with UDPGA were found to convert both toxins into two glucuronides each, but HT-29 cells exhibited a much high activity than HepG2 cells and gave rise to a different ratio of glucuronides. It is concluded that glucuronidation eliminates the DNA strandbreaking potential of AOH and AME, and that the two glucuronides of eachAlternaria toxin are generated by different UGT isoforms. Presented at the 29^th Mykotoxin-Workshop, Fellbach, Germany, May 14–16, 2007 Financial support: State of Baden-Württemberg (Research Program “Mycotoxins” as part of the Research Initiative “Food and Health”)     

Expression of plant antimicrobial peptide <Emphasis Type="Italic">pro-SmAMP2</Emphasis> gene increases resistance of transgenic potato plants to <Emphasis Type="Italic">Alternaria</Emphasis> and <Emphasis Type="Italic">Fusarium</Emphasis> pathogens

The chickweed (Stellaria media L.) pro-SmAMP2 gene encodes the hevein-like peptides that have in vitro antimicrobial activity against certain harmful microorganisms. These peptides play an important role in protecting the chickweed plants from infection, and the pro-SmAMP2 gene was previously used to protect transgenic tobacco and Arabidopsis plants from phytopathogens. In this study, the pro-SmAMP2 gene under control of viral CaMV35S promoter or under control of its own pro-SmAMP2 promoter was transformed into cultivated potato plants of two cultivars, differing in the resistance to Alternaria: Yubiley Zhukova (resistant) and Skoroplodny (susceptible). With the help of quantitative real-time PCR, it was demonstrated that transgenic potato plants expressed the pro-SmAMP2 gene under control of both promoters at the level comparable to or exceeding the level of the potato actin gene. Assessment of the immune status of the transformants demonstrated that expression of antimicrobial peptide pro-SmAMP2 gene was able to increase the resistance to a complex of Alternaria sp. and Fusarium sp. phytopathogens only in potato plants of the Yubiley Zhukova cultivar. The possible role of the pro-SmAMP2 products in protecting potatoes from Alternaria sp. and Fusarium sp. is discussed.     

Taxonomic study on <Emphasis Type="Italic">Alternaria</Emphasis> sections <Emphasis Type="Italic">Infectoriae</Emphasis> and <Emphasis Type="Italic">Pseudoalternaria</Emphasis> associated with black (sooty) head mold of wheat and barley in Iran

During the spring and summer of 2014 and 2015, wheat and barley fields in the Iranian provinces of Golestan and Alborz showed a high incidence of symptoms of black (sooty) head mold of wheat and barley. The isolation results revealed that Alternaria was associated with these symptoms. One hundred and forty isolates were collected and morphologically characterized based on the development of conidial chains with primary, secondary, and tertiary branching patterns, consistent with the three-dimensional sporulation complexity of members of Alternaria in sections Infectoriae and Pseudoalternaria. Subsequently, 16 Alternaria isolates exhibiting high morphological diversity were characterized based on extensive morphological and molecular comparisons. Phylogenetic analyses of three loci [ITS, glyceraldehyde 3-phosphate dehydrogenase (gpd), and plasma membrane ATPase (ATPase)] revealed that 15 isolates belonged to section Infectoriae but could not be assigned to phylogenetic species and one isolate represents a new species, Alternaria kordkuyana sp. nov., in section Pseudoalternaria. Morphological assessments revealed a high degree of variation among section Infectoriae isolates and that A. kordkuyana has significant morphological differences as compared to the three other species currently described in section Pseudoalternaria.     

First volumetric record of fungal spores in the atmosphere of Montevideo City,Uruguay: a 2-year survey

In Uruguay, aeromycological studies are restricted to a gravimetric analysis performed from December 1942 to March 1944 in Montevideo where spores of Pucciniaceae, Alternaria and Helminthosporium were the only specimens identified. Daily monitoring of airborne fungal spores was carried out for the first time in Montevideo, from April 2012 to March 2014, using a Rotorod sampler in order to evaluate the seasonal variation and influence of meteorological parameters. A total of 548,309.68 spores/m³ were recorded which belong to anamorphs of Higher Fungi (69.18 %), Phyla Ascomycota (12.62 %), Basidiomycota (8.01 %), Oomycota (0.37 %) and Myxomycota (0.06 %). Airborne spores occurred in Montevideo throughout the whole year. However, a seasonal pattern was revealed, with the highest concentrations recorded in autumn and summer. The most abundant spore types were Cladosporium (53.22 %), Alternaria (6.62 %), Didymella Group (5.86 %), Leptosphaeria Group (4.37 %) and Coprinus (4.3 %). Temperature appeared to be the most influential meteorological factor correlating significantly and positively with total spore, Cladosporium, Alternaria and Didymella Group abundance. Relative humidity influenced positively total spore, Cladosporium and Didymella Group concentrations while a weak negative association was obtained for Alternaria. Wind speed correlated negatively with total spore, Cladosporium, Alternaria and Didymella Group. Precipitation showed a negative influence on Alternaria, while positive correlations were observed for Didymella Group. For the first time, fungal spores considered allergenic were recorded in Montevideo atmosphere and the risk of exposure would have been high from December to June. However, long-term sampling is needed to define seasonal prevalence patterns and the influence of meteorological conditions on spore abundance.