Aflatoxin profiles of Aspergillus flavus isolates in Sudanese fungal rhinosinusitis

Aspergillus flavus is a commonly encountered pathogen responsible for fungal rhinosinusitis (FRS) in arid regions. The species is known to produce aflatoxins, posing a significant risk to human health. This study aimed to investigate the aflatoxin profiles of A. flavus isolates causing FRS in Sudan. A total of 93 clinical and 34 environmental A. flavus isolates were studied. Aflatoxin profiles were evaluated by phenotypic (thin-layer and high-performance chromatography) and genotypic methods at various temperatures and substrates. Gene expression of aflD and aflR was also analyzed. A total of 42/93 (45%) isolates were positive for aflatoxin B1 and AFB2 by HPLC. When the incubation temperature changed from 28°C to 36°C, the number of positive isolates decreased to 41% (38/93). Genetic analysis revealed that 85% (79/93) of clinical isolates possessed all seven aflatoxin biosynthesis-associated genes, while 27% (14/51) of non-producing isolates lacked specific genes (aflD/aflR/aflS). Mutations were observed in aflS and aflR genes across both aflatoxin-producers and non-producers. Gene expression of aflD and aflR showed the highest expression between the 4th and 6th days of incubation on the Sabouraud medium and on the 9th day of incubation on the RPMI (Roswell Park Memorial Institute) medium. Aspergillus flavus clinical isolates demonstrated aflatoxigenic capabilities, influenced by incubation temperature and substrate. Dynamic aflD and aflR gene expression patterns over time enriched our understanding of aflatoxin production regulation. The overall findings underscored the health risks of Sudanese patients infected by this species, emphasizing the importance of monitoring aflatoxin exposure.

Characterization of 260 Isolates of Aspergillus Section Flavi Obtained from Sesame Seeds in Punjab, Pakistan

Sesame Sesamum indicum L. is a major oil-based seed crop that has been widely cultivated and consumed in Pakistan. Unfortunately, sesame is highly prone to Aspergillus fungal growth in the field, and under inappropriate storage conditions can become contaminated with aflatoxins, the most potent carcinogen found in nature. Here, we have isolated a high number of Aspergillus isolates from sesame seeds in fresh and stored conditions obtained from rainfed and irrigated zones of Punjab, Pakistan, and characterized them for aflatoxigenic potentials. Using morphological identification techniques, 260 isolates were grouped as potential Aspergillus section Flavi, with 126 and 134 originating from the rainfed and irrigated zones, respectively. Out of 260 in total, 188 isolates were confirmed to produce aflatoxins. There were no significant differences in potential aflatoxigenic isolates with respect to the rainfed and irrigated zones. However, the number of potential aflatoxigenic isolates was significantly higher (p < 0.05) in stored samples than that of those from fresh sesame seeds in the rainfed and irrigated zone. Whole genome sequencing and comparative analyses of 12 select isolates have revealed that one of the A. flavus isolates, which produced very low aflatoxins (AFP10), has an elevated missense variant rate, numerous high impact mutations, and a 600 base pair deletion in the norB gene. In summary, our study provides insights into aflatoxigenic potential and the associated genetic diversity of indigenous Aspergillus section Flavi isolates and potential management strategies for reducing aflatoxin contamination levels in a major crop consumed in Punjab, Pakistan.

The AFLATOX® Project: Approaching the Development of New Generation, Natural-Based Compounds for the Containment of the Mycotoxigenic Phytopathogen Aspergillus flavus and Aflatoxin Contamination

The control of the fungal contamination on crops is considered a priority by the sanitary authorities of an increasing number of countries, and this is also due to the fact that the geographic areas interested in mycotoxin outbreaks are widening. Among the different pre- and post-harvest strategies that may be applied to prevent fungal and/or aflatoxin contamination, fungicides still play a prominent role; however, despite of countless efforts, to date the problem of food and feed contamination remains unsolved, since the essential factors that affect aflatoxins production are various and hardly to handle as a whole. In this scenario, the exploitation of bioactive natural sources to obtain new agents presenting novel mechanisms of action may represent a successful strategy to minimize, at the same time, aflatoxin contamination and the use of toxic pesticides. The Aflatox® Project was aimed at the development of new-generation inhibitors of aflatoxigenic Aspergillus spp. proliferation and toxin production, through the modification of naturally occurring molecules: a panel of 177 compounds, belonging to the thiosemicarbazones class, have been synthesized and screened for their antifungal and anti-aflatoxigenic potential. The most effective compounds, selected as the best candidates as aflatoxin containment agents, were also evaluated in terms of cytotoxicity, genotoxicity and epi-genotoxicity to exclude potential harmful effect on the human health, the plants on which fungi grow and the whole ecosystem.

Alterations in Fecal Fungal Microbiome of Patients With COVID-19 During Time of Hospitalization until Discharge

BACKGROUND & AIMS

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infects intestinal cells, and might affect the intestinal microbiota. We investigated changes in the fecal fungal microbiomes (mycobiome) of patients with SARS-CoV-2 infection during hospitalization and on recovery.

METHODS

We performed deep shotgun metagenomic sequencing analysis of fecal samples from 30 patients with coronavirus disease 2019 (COVID-19) in Hong Kong, from February 5 through May 12, 2020. Fecal samples were collected 2 to 3 times per week from time of hospitalization until discharge. We compared fecal mycobiome compositions of patients with COVID-19 with those from 9 subjects with community-acquired pneumonia and 30 healthy individuals (controls). We assessed fecal mycobiome profiles throughout time of hospitalization until clearance of SARS-CoV-2 from nasopharyngeal samples.

RESULTS

Patients with COVID-19 had significant alterations in their fecal mycobiomes compared with controls, characterized by enrichment of Candia albicans and a highly heterogeneous mycobiome configuration, at time of hospitalization. Although fecal mycobiomes of 22 patients with COVID-19 did not differ significantly from those of controls during times of hospitalization, 8 of 30 patients with COVID-19 had continued significant differences in fecal mycobiome composition, through the last sample collected. The diversity of the fecal mycobiome of the last sample collected from patients with COVID-19 was 2.5-fold higher than that of controls (P < .05). Samples collected at all timepoints from patients with COVID-19 had increased proportions of opportunistic fungal pathogens, Candida albicans, Candida auris, and Aspergillus flavus compared with controls. Two respiratory-associated fungal pathogens, A. flavus and Aspergillus niger, were detected in fecal samples from a subset of patients with COVID-19, even after clearance of SARS-CoV-2 from nasopharyngeal samples and resolution of respiratory symptoms.

CONCLUSIONS

In a pilot study, we found heterogeneous configurations of the fecal mycobiome, with enrichment of fungal pathogens from the genera Candida and Aspergillus, during hospitalization of 30 patients with COVID-19 compared with controls. Unstable gut mycobiomes and prolonged dysbiosis persisted in a subset of patients with COVID-19 up to 12 days after nasopharyngeal clearance of SARS-CoV-2. Studies are needed to determine whether alterations in intestinal fungi contribute to or result from SARS-CoV-2 infection, and the effects of these changes in disease progression.

Maxillary fungus ball in a diabetic patient. An odontogenic origin

INTRODUCTION

Fungus ball (FB) represents a granulomatous mass due to a fungal colonization which may disseminate and potentially lead to a systemic infection. Maxillary fungus ball is considered to be a complication of dental treatment and, according to relevant literature, it often stems from improper endodontic therapies.

MATERIAL AND METHODS

The authors report the case of a 69-year-old caucasian woman with nasal respiratory distress and frequent sinusitis symptoms. According to clinical and radiological evidence, FESS surgery was planned, thus validating FB diagnostic hypothesis.

CONCLUSIONS

Fungal infection should always be considered in patients with sinusitis and previous root canal theraphy. Misdiagnosis can lead to severe complications. Surgical removal seems to be effective and resolutive.

KEY WORDS

Endoscopic surgery, Fungus Ball, Maxillary sinusitiss.

Aspergillus mediastinitis in a post-operative immunocompetent child

Post-operative Aspergillus mediastinitis is regarded to be a devastating infection, usually affecting patients undergoing cardiothoracic surgery with specific predisposing factors characterised by a high mortality and chronic morbidity. Patient outcome after such a complication is extremely poor despite antifungal therapy and surgery. We describe the case of an immunocompetent 2-month-old child with obstructed supracardiac total anomalous pulmonary venous circulation (TAPVC) and severe pulmonary artery hypertension, who underwent TAPVC repair through median sternotomy and developed post-operative mediastinitis due to Aspergillus flavus.

Activity of a Long-Acting Echinocandin, Rezafungin, and Comparator Antifungal Agents Tested against Contemporary Invasive Fungal Isolates (SENTRY Program, 2016 to 2018)

We evaluated the activity of rezafungin and comparators, using Clinical and Laboratory Standards Institute (CLSI) broth microdilution methods, against a worldwide collection of 2,205 invasive fungal isolates recovered from 2016 to 2018. Candida (n = 1,904 isolates; 6 species), Cryptococcus neoformans (n = 73), Aspergillus fumigatus (n = 183), and Aspergillus flavus (n = 45) isolates were tested for their susceptibility (S) to rezafungin as well as the comparators caspofungin, anidulafungin, micafungin, and azoles. Interpretive criteria were applied following CLSI published clinical breakpoints (CBPs) and epidemiological cutoff values (ECVs). Isolates displaying non-wild-type (non-WT) echinocandin MIC values were sequenced for hot spot (HS) mutations. Rezafungin inhibited 99.8% of Candida albicans isolates (MIC50/90, 0.03/0.06 μg/ml), 95.7% of Candida glabrata isolates (MIC50/90, 0.06/0.12 μg/ml), 97.4% of Candida tropicalis isolates (MIC50/90, 0.03/0.06 μg/ml), 100.0% of Candida krusei isolates (MIC50/90, 0.03/0.06 μg/ml), and 100.0% of Candida dubliniensis isolates (MIC50/90, 0.06/0.12 μg/ml) at ≤0.12 μg/ml. All (329/329 [100.0%]) Candida parapsilosis isolates (MIC50/90,1/2 μg/ml) were inhibited by rezafungin at ≤4 μg/ml. Fluconazole resistance was detected among 8.6% of C. glabrata isolates, 12.5% of C. parapsilosis isolates, 3.2% of C. dubliniensis isolates, and 2.6% of C. tropicalis isolates. The activity of rezafungin against these 6 Candida spp. was similar to the activity of the other echinocandins. Detection of the HS mutation was performed by sequencing echinocandin-resistant or non-WT Candida isolates. Good activity against C. neoformans was observed for fluconazole and the other azoles, whereas the echinocandins, including rezafungin, displayed limited activity. Rezafungin displayed activity similar to that of the other echinocandins against A. fumigatus and A. flavus These in vitro data contribute to accumulating research demonstrating the potential of rezafungin for preventing and treating invasive fungal infections.

Comprehensive comparison of multiple quantitative near-infrared spectroscopy models for Aspergillus flavus contamination detection in peanut

BACKGROUND

Aspergillus flavus is a major pollutant in moldy peanuts, and it has a large influence on the taste of food. The secondary metabolites of Aspergillus flavus, including aflatoxin B1 (AFB1) and aflatoxin B2 (AFB2), are highly toxic and can expose humans to high risk. The total mold count (TMC) is an important index to determine the contamination degree and hygiene quality of peanut.

RESULTS

Quantitative calibration models were established based on full-band wavelengths and characteristic wavelengths, combined with chemometric methods, to explore the feasibility of the use of near-infrared spectroscopy (NIRS) for rapid detection of the TMC in peanuts. The successive projection algorithm (SPA) and elimination of uninformative variables (UVE) algorithms were used to extract the characteristic wavelengths. In comparison, the model built by original spectrum, selected with the UVE algorithm, gave the best result, with a correlation coefficient in a prediction set (R_P ) of 0.9577, a root mean square error for the prediction set (RMSEP) of 0.2336 Log CFU/g, and a residual predictive deviation (RPD) of 3.5041.

CONCLUSIONS

The results showed that NIRS is a rapid, practicable method for the quantitative detection of peanut Aspergillus flavus contamination. It is a promising method for detecting moldy peanuts and increasing peanut safety. © 2019 Society of Chemical Industry.

An atoxigenic L-strain of Aspergillus flavus (Eurotiales: Trichocomaceae) is pathogenic to the coffee twig borer, Xylosandrus compactus (Coleoptera: Curculionidea: Scolytinae)

This study isolated and evaluated virulence of fungal entomopathogens of Xylosandrus compactus - an important pest of Robusta coffee in Sub-Saharan Africa. A survey was conducted in five farming systems in Uganda to isolate entomopathogens associated with X. compactus. Four fungal isolates were screened for virulence against X. compactus in the laboratory at 1 × 10⁷ conidia ml^-1 where an atoxigenic L-strain of A. flavus killed 70%-100% of all stages of X. compactus compared with other unidentified isolates which caused 20%-70% mortalities. The time taken by A. flavus to kill 50% of X. compactus eggs, larvae, pupae and adults in the laboratory was 2-3 days; whereas the other unidentified fungal isolates took 4-7 days. The concentrations of A. flavus that killed 50% of different stages of X. compactus were 5 × 10⁵ , 12 × 10⁵ , 17 × 10⁵ and 30 × 10⁵ conidia ml^-1 for larvae, eggs, pupae and adults respectively. A formulation of A. flavus in oil caused higher mortalities of X. compactus larvae, pupae and adults in the field (71%-79%) than its formulation in water (33%-47%). The atoxigenic strain of A. flavus could therefore be developed into a safe biopesticide against X. compactus.

Osteomyelitis of the rib cage by Aspergillus flavus

BACKGROUND

Aspergillus osteomyelitis of the ribs is relatively uncommon. It is a debilitating and severe form of invasive aspergillosis.

CASE REPORT

A 61year-old female presented with spontaneous chest pain on the right side of the rib cage and a palpable soft-tissue mass. FDG-PET/CT scan identified activity in the infected site. The lesion was punctured, and purulent material was sent to the laboratory. Aspergillus complex Flavi was isolated. An antifungal treatment with voriconazole was started. The lesion healed, and no recurrence was observed at 8-month follow-up. Molecular identification of the isolate was based on PCR amplification and sequencing of β-tubulin gene. Aspergillus flavus was identified.

CONCLUSIONS

Our case highlights the relevance of microbiological studies in patients with osteomyelitis and the involvement of soft tissue. The FDG-PET/CT scan was found to be a useful tool for revealing the extent of the disease and evaluating the response to the antifungal therapy.

Aflatoxin production and in vitro toxicity of Aspergilli section Flavi isolated from air samples collected from different environments

Aspergilli section Flavi, originally isolated from air samples collected from inhabited apartments (AP), unoccupied basements (BS), and processing facilities of a grain mill (GM), were analyzed for their potential to produce aflatoxin B₁ (AFB₁) on solid media. The isolates were further characterized with regard to their cytotoxic, genotoxic, and pro-inflammatory properties in vitro. Aspergilli were identified based on partial calmodulin (CaM) gene sequencing; the producing capacities of isolates were analyzed by HPLC/FLD and confirmed by genes in biosynthesis (aflR, norA, omtA). In the grain mill, the Aspergilli section Flavi (up to 1.3 × 10⁶ cfu/m³) dominated by AFB₁-producing Aspergillus flavus (71%, 4.5-5254 ng/ml) which showed a serious health risk for workers. Living environments were not relevant sources of exposure. After 24 h, AFB₁ (1-100 μmol/l) reduced cell viability (MTT test) in both A549 cells and THP-1 macrophage-like cells without reaching IC₅₀. In A549 cells, the extract of the AFB₁-producing A. flavus significantly decreased cell viability but not below 50%. THP-1 macrophage-like cells were more sensitive to both extracts, but IC₅₀ was obtained only for the AFB₁-producing strain (0.37 mg/ml; AFB₁ 2.78 μmol/l). AFB₁ (1 and 10 μmol/l) induced significant DNA damage (tail intensity, alkaline comet assay) in A549 cells in contrast to Aspergilli extracts. AFB₁ elevated IL-6 and IL-8, while Aspergilli extracts increased IL-1β, TNF-α, and IL-17 release in THP-1 macrophages (ELISA). Chronic exposure to AFB₁ and/or other metabolites in airborne A. flavus from occupational environments may stimulate epithelial damage of airways accompanied by lowered macrophage viability.

Fatal case of cerebral aspergilloma complicated by ventriculitis and bacteremia due to Salmonella species in a sickle cell disease patient

To describe a fatal case of invasive Aspergillus flavus sinusitis in a 43-year old female with sickle cell disease (SCD) complicated by intracerebral aspergilloma and invasive Salmonella infection. Cerebral aspergilloma carries a very high mortality rate. The patient developed post-craniotomy intracerebral hemorrhage at the site of biopsy, Salmonella species sepsis and ventriculitis. She presented with a 2-month history of headache, dizziness, personality and behavioral changes, and vomiting. Initial clinical evaluation raised the suspicion of brain tumor. Brain magnetic resonance imaging revealed a left frontal, thick-walled ring-enhancing lesion with extensive surrounding edema suggestive of a neoplastic lesion, or a contiguous inflammatory or infectious process from the skull base. Despite early diagnosis and appropriate antifungal and surgical management, she eventually died from severe infection and respiratory arrest. In conclusion, invasive aspergillosis should be included in the differential diagnosis of SCD patients with central nervous system (CNS) lesions.

Magnitude of Voriconazole Resistance in Clinical and Environmental Isolates of Aspergillus flavus and Investigation into the Role of Multidrug Efflux Pumps

The magnitude of azole resistance in Aspergillus flavus and its underlying mechanism is obscure. We evaluated the frequency of azole resistance in a collection of clinical (n = 121) and environmental isolates (n = 68) of A. flavus by the broth microdilution method. Six (5%) clinical isolates displayed voriconazole MIC greater than the epidemiological cutoff value. Two of these isolates with non-wild-type MIC were isolated from same patient and were genetically distinct, which was confirmed by amplified fragment length polymorphism analysis. Mutations associated with azole resistance were not present in the lanosterol 14-α demethylase coding genes (cyp51A, cyp51B, and cyp51C). Basal and voriconazole-induced expression of cyp51A homologs and various efflux pump genes was analyzed in three each of non-wild-type and wild-type isolates. All of the efflux pump genes screened showed low basal expression irrespective of the azole susceptibility of the isolate. However, the non-wild-type isolates demonstrated heterogeneous overexpression of many efflux pumps and the target enzyme coding genes in response to induction with voriconazole (1 μg/ml). The most distinctive observation was approximately 8- to 9-fold voriconazole-induced overexpression of an ortholog of the Candida albicans ATP binding cassette (ABC) multidrug efflux transporter, Cdr1, in two non-wild-type isolates compared to those in the reference strain A. flavus ATCC 204304 and other wild-type strains. Although the dominant marker of azole resistance in A. flavus is still elusive, the current study proposes the possible role of multidrug efflux pumps, especially that of Cdr1B overexpression, in contributing azole resistance in A. flavus.

Orbital granulomatosis with polyangiitis masquerading as invasive fungal sinusitis

A 55-year-old man presented with unilateral orbital inflammation and no light perception vision. Imaging revealed infiltrative enhancement of the optic nerve, orbit, and intracranial tissue. The case was suspicious for invasive fungal disease, but ultimate workup and orbital biopsy revealed granulomatosis with polyangiitis. The patient's inflammation resolved with corticosteroid and rituximab therapy. Granulomatosis with polyangiitis is a systemic vasculitis that can mimic a number of orbital pathologies.

Fungal communities associated with almond throughout crop development: Implications for aflatoxin biocontrol management in California

Interactions between pathogenic and nonpathogenic fungal species in the tree canopy are complex and can determine if disease will manifest in the plant and in other organisms such as honey bees. Seasonal dynamics of fungi were studied in an almond orchard in California where experimental release of the atoxigenic biopesticide Aspergillus flavus AF36 to displace toxigenic Aspergillus strains has been conducted for five years. The presence of the vegetative compatibility group (VCG) YV36, to which AF36 belongs, in the blossoms, and the honey bees that attend these blossoms, was assessed. In blossoms, A. flavus frequencies ranged from 0 to 4.5%, depending on the year of study. Frequencies of honey bees carrying A. flavus ranged from 6.5 to 10%. Only one A. flavus isolate recovered from a blossom in 2016 belonged to YV36, while members of the VCG were not detected contaminating honey bees. Exposure of pollinator honey bees to AF36 was detected to be very low. The density of several Aspergillus species was found to increase during almond hull split and throughout the final stages of maturation; this also occurred in pistachio orchards during the maturation period. Additionally, we found that AF36 effectively limited almond aflatoxin contamination in laboratory assays. This study provides knowledge and understanding of the seasonal dynamics of Aspergillus fungi and will help design aflatoxin management strategies for almond. The evidence of the low levels of VCG YV36 encountered on almond blossoms and bees during pollination and AF36's effectiveness in limiting aflatoxin contamination in almond provided additional support for the registration of AF36 with USEPA to use in almond in California.

Herbicidal activity of pure compound isolated from rhizosphere inhabiting Aspergillus flavus

In the quest for bioactive natural products of fungal origin, Aspergillus flavus was isolated from rhizosphere of Mentha piperita using Potato Dextrose Agar (PDA) and Czapec Yeast Broth (CYB) nutrient media for metabolites production. In total, three different metabolites were purified using HPLC/LCMS and the structures were established using 500 Varian NMR experiments. Further the isolated metabolites in different concentrations (10, 100, 1000 μg/mL) were tested for herbicidal activity using Completely Randomized design (CRD) against the seeds of Silybum marianum and Avena fatua which are major threats to wheat crop in Pakistan. Among the isolated metabolites, one compound was found active against the test weed species whose activity is reported in the present work. The chemical name of the compound is 2-(1, 4-dihydroxybutan-2-yl)-1, 3-dihydroxy-6, 8-dimethoxyanthracene-9, 10(4aH, 9aH)-dione with mass of 388. Results showed that all seeds germinated in control treatment; however, with the metabolite treated, the growth was retarded to different levels in all parts of the weeds. At a dose of 1000 μg/mL of the pure compound, 100% seeds of S. marianum and 60% seeds of A. fatua were inhibited. Interestingly, the pure compound exhibited less inhibition of 10% towards the seeds of common wheat (Triticum aestivum).

Isolation and characterization of Aspergillus flavus strains in China

Important staple foods (peanuts, maize and rice) are susceptible to contamination by aflatoxin (AF)-producing fungi such as Aspergillus flavus. The objective of this study was to explore non-aflatoxin-producing (atoxigenic) A. flavus strains as biocontrol agents for the control of AFs. In the current study, a total of 724 A. flavus strains were isolated from different regions of China. Polyphasic approaches were utilized for species identification. Non-aflatoxin and non-cyclopiazonic acid (CPA)-producing strains were further screened for aflatoxin B₁ (AFB₁) biosynthesis pathway gene clusters using a PCR assay. Strains lacking an amplicon for the regulatory gene aflR were then analyzed for the presence of the other 28 biosynthetic genes. Only 229 (32%) of the A. flavus strains were found to be atoxigenic. Smaller (S) sclerotial phenotypes were dominant (51%) compared to large (L, 34%) and non-sclerotial (NS, 15%) phenotypes. Among the atoxigenic strains, 24 strains were PCR-negative for the fas-1 and aflJ genes. Sixteen (67%) atoxigenic A. flavus strains were PCRnegative for 10 or more of the biosynthetic genes. Altogether, 18 new PCR product patterns were observed, indicating great diversity in the AFB₁ biosynthesis pathway. The current study demonstrates that many atoxigenic A. flavus strains can be isolated from different regions of China. In the future laboratory as well as field based studies are recommended to test these atoxigenic strains as biocontrol agents for aflatoxin contamination.

In Vitro Combination of Isavuconazole with Echinocandins against Azole-Susceptible and -Resistant Aspergillus spp

In vitro combinations of isavuconazole with echinocandins were evaluated against 30 Aspergillus strains with a two-dimensional checkerboard microdilution method and an agar-based diffusion method. With the checkerboard method, the three combinations showed indifferent interactions for all strains. With the agar-based method, indifferent interactions were found for all strains for isavuconazole-micafungin and isavuconazole-anidulafungin. For the isavuconazole-caspofungin combination, indifference was found in 24/30 strains, synergism in 4/30 strains, and antagonism in 2/30 strains.

In vitro antifungal susceptibility of clinical and environmental isolates of Aspergillus fumigatus and Aspergillus flavus in Brazil

The in vitro susceptibility of 105 clinical and environmental strains of Aspergillus fumigatus and Aspergillus flavus to antifungal drugs, such as amphotericin B, azoles, and echinocandins was evaluated by the broth microdilution method proposed by the European Committee on Antimicrobial Susceptibility Testing (EUCAST). Following the EUCAST-proposed breakpoints, 20% and 25% of the clinical and environmental isolates of A. fumigatus, respectively, were found to be resistant to itraconazole (Minimal Inhibitory Concentration, MIC > 2.0 mg/L). Voriconazole showed good activity against A. fumigatus and A. flavus strains, except for one clinical strain of A. fumigatus whose MIC was 4.0 mg/L. Posaconazole (≤0.25 mg/L) also showed appreciable activity against both species of Aspergillus, except for six A. fumigatus strains with relatively higher MICs (0.5 mg/L). The MICs for Amphotericin B ranged from 0.06 to 1.0 mg/L for A. fumigatus, but were much higher (0.5–8.0 mg/L) for A. flavus. Among the echinocandins, caspofungin showed a geometric mean of 0.078 and 0.113 against the clinical and environmental strains of A. flavus, respectively, but had elevated minimal effective concentrations (MECs) for seven of the A. fumigatus strains. Anidulafungin and micafungin exhibited considerable activity against both A. fumigatus and A. flavus isolates, except for one environmental isolate of A. fumigatus that showed an MEC of 1 mg/L to micafungin. Our study proposes that a detailed investigation of the antifungal susceptibility of the genus Aspergillus from different regions of Brazil is necessary for establishing a response profile against the different classes of antifungal agents used in the treatment of aspergillosis.

Combined genotyping strategy reveals structural differences between Aspergillus flavus lineages from different habitats impacting human health

Aspergillus flavus is a filamentous fungus which is widespread on agricultural products and also able to cause various human diseases. This species is frequently isolated from indoor air as well, furthermore, it is known as a common causal agent of keratomycosis, particularly in subtropical and tropical areas. It is also able to produce aflatoxins, one of the most carcinogenic mycotoxins which are harmful to animals and humans. In this study, 59 A. flavus isolates from four different habitats and 1 A. minisclerotigenes isolate were investigated. The isolates were identified and confirmed at the species level by the sequence analysis of a part of their calmodulin gene. Applying a combined analysis of UP-PCR, microsatellite, and calmodulin sequence data, the four group of isolates formed separate clusters on the phylogenetic tree. Examining the distribution of mating type genes MAT1-1 and MAT1-2, a ratio of approximately 3:1 was determined, and no correlation was found between the carried mating type gene and the aflatoxin production capability. HPLC analysis revealed that none of the examined isolates collected from indoor air or maize in Central Europe were able to produce aflatoxins, while about half of the isolates from India produced these mycotoxins under the test conditions.

Characterization of Aspergillus section Flavi isolated from fresh chestnuts and along the chestnut flour process

An extensive sampling of Aspergillus section Flavi considered to be the main agent responsible for aflatoxin contamination, was carried out in the field and along the processing phases of chestnut flour production in 2015. Fifty-eight isolates were characterized by means of biological, molecular and chemical assays. The highest incidence of Aspergillus section Flavi was found in the field. The identification of the isolates was based on β-tubulin and calmodulin gene sequences. A. flavus was found to be the dominant species, and this was followed by A. oryzae var effusus, A. tamarii, A. parasiticus and A. toxicarius. Nineteen percent of the strains produced aflatoxins in vitro and forty percent in vivo. The pathogenicity assay on chestnut showed 56 virulent strains out of 58. The molecular, morphological, chemical and biological analyses of A. flavus strains showed an intraspecific variability. These results confirm that a polyphasic approach is necessary to discriminate the species inside the Aspergillus section Flavi. The present research is the first monitoring and characterization of aflatoxigenic fungi from fresh chestnut and the chestnut flour process, and it highlights the risk of a potential contamination along the whole chestnut production chain.

Cyclopiazonic Acid Is a Pathogenicity Factor for Aspergillus flavus and a Promising Target for Screening Germplasm for Ear Rot Resistance

Aspergillus flavus, an opportunistic pathogen, contaminates maize and other key crops with carcinogenic aflatoxins (AFs). Besides AFs, A. flavus makes many more secondary metabolites (SMs) whose toxicity in insects or vertebrates has been studied. However, the role of SMs in the invasion of plant hosts by A. flavus remains to be investigated. Cyclopiazonic acid (CPA), a neurotoxic SM made by A. flavus, is a nanomolar inhibitor of endoplasmic reticulum calcium ATPases (ECAs) and a potent inducer of cell death in plants. We hypothesized that CPA, by virtue of its cytotoxicity, may serve as a key pathogenicity factor that kills plant cells and supports the saprophytic life style of the fungus while compromising the host defense response. This proposal was tested by two complementary approaches. A comparison of CPA levels among A. flavus isolates indicated that CPA may be a determinant of niche adaptation, i.e., isolates that colonize maize make more CPA than those restricted only to the soil. Further, mutants in the CPA biosynthetic pathway are less virulent in causing ear rot than their wild-type parent in field inoculation assays. Additionally, genes encoding ECAs are expressed in developing maize seeds and are induced by A. flavus infection. Building on these results, we developed a seedling assay in which maize roots were exposed to CPA, and cell death was measured as Evans Blue uptake. Among >40 maize inbreds screened for CPA tolerance, inbreds with proven susceptibility to ear rot were also highly CPA sensitive. The publicly available data on resistance to silk colonization or AF contamination for many of the lines was also broadly correlated with their CPA sensitivity. In summary, our studies show that i) CPA serves as a key pathogenicity factor that enables the saprophytic life style of A. flavus and ii) maize inbreds are diverse in their tolerance to CPA. Taking advantage of this natural variation, we are currently pursuing both genome-wide and candidate gene approaches to identify novel components of maize resistance to Aspergillus ear rot.

Ameliorative Effects of Neutral Electrolyzed Water on Growth Performance, Biochemical Constituents, and Histopathological Changes in Turkey Poults during Aflatoxicosis

Different in vitro and in silico approaches from our research group have demonstrated that neutral electrolyzed water (NEW) can be used to detoxify aflatoxins. The objective of this investigation was to evaluate the ability of NEW to detoxify B-aflatoxins (AFB₁ and AFB₂) in contaminated maize and to confirm detoxification in an in vivo experimental model. Batches of aflatoxin-contaminated maize were detoxified with NEW and mixed in commercial feed. A total of 240 6-day-old female large white Nicholas-700 turkey poults were randomly divided into four treatments of six replicates each (10 turkeys per replicate), which were fed ad libitum for two weeks with the following dietary treatments: (1) control feed containing aflatoxin-free maize (CONTROL); (2) feed containing the aflatoxin-contaminated maize (AF); (3) feed containing the aflatoxin-contaminated maize detoxified with NEW (AF + NEW); and (4) control feed containing aflatoxin-free maize treated with NEW (NEW). Compared to the control groups, turkey poults of the AF group significantly reduced body weight gain and increased feed conversion ratio and mortality rate; whereas turkey poults of the AF + NEW group did not present significant differences on productive parameters. In addition, alterations in serum biochemical constituents, enzyme activities, relative organ weight, gross morphological changes and histopathological studies were significantly mitigated by the aflatoxin-detoxification procedure. From these results, it is concluded that the treatment of aflatoxin-contaminated maize with NEW provided reasonable protection against the effects caused by aflatoxins in young turkey poults.

Detection of aflatoxin and surface mould contaminated figs by using Fourier transform near-infrared reflectance spectroscopy

BACKGROUND

Aflatoxins are toxic metabolites that are mainly produced by members of the Aspergillus section Flavi on many agricultural products. Certain agricultural products such as figs are known to be high risk products for aflatoxin contamination. Aflatoxin contaminated figs may show a bright greenish yellow fluorescence (BGYF) under ultraviolet (UV) light at a wavelength of 365 nm. Traditionally, BGYF positive figs are manually selected by workers. However, manual selection depends on the expertise level of the workers and it may cause them skin-related health problems due to UV radiation.

RESULTS

In this study, we propose a non-invasive approach to detect aflatoxin and surface mould contaminated figs by using Fourier transform near-infrared (FT-NIR) reflectance spectroscopy. A classification accuracy of 100% is achieved for classifying the figs into aflatoxin contaminated/uncontaminated and surface mould contaminated/uncontaminated categories. In addition, a strong correlation has been found between aflatoxin and surface mould.

CONCLUSION

Combined with pattern classification methods, the NIR spectroscopy can be used to detect aflatoxin contaminated figs non-invasively. Furthermore, a positive correlation between surface mould and aflatoxin contamination leads to a promising alternative indicator for the detection of aflatoxin-contaminated figs. © 2016 Society of Chemical Industry.

Aflatoxigenic Aspergillus flavus and Aspergillus parasiticus strains in Hungarian maize fields

Due to the climate change, aflatoxigenic Aspergillus species and strains have appeared in several European countries, contaminating different agricultural commodities with aflatoxin. Our aim was to screen the presence of aflatoxigenic fungi in maize fields throughout the seven geographic regions of Hungary. Fungi belonging to Aspergillus section Flavi were isolated in the ratio of 26.9% and 42.3% from soil and maize samples in 2013, and these ratios decreased to 16.1% and 34.7% in 2014. Based on morphological characteristics and the sequence analysis of the partial calmodulin gene, all isolates proved to be Aspergillus flavus, except four strains, which were identified as Aspergillus parasiticus. About half of the A. flavus strains and all the A. parasiticus strains were able to synthesize aflatoxins. Aflatoxigenic Aspergillus strains were isolated from all the seven regions of Hungary. A. parasiticus strains were found in the soil of the regions Southern Great Plain and Southern Transdanubia and in a maize sample of the region Western Transdanubia. In spite of the fact that aflatoxins have rarely been detected in feeds and foods in Hungary, aflatoxigenic A. flavus and A. parasiticus strains are present in the maize culture throughout Hungary posing a potential threat to food safety.

Monitoring of aflatoxin G1, B1, G2, and B2 occurrence in some samples of walnut

This research was conducted to monitor the aflatoxigenic fungi and aflatoxin contamination of walnut in the Hamedan province. For this purpose, 40 samples were analyzed. Aspergillus, Alternaria, Rhizopus, Cladosporium, Fusarium, yeast, and some different bacteria were isolated from walnuts. Aspergillus is the most frequent genus. Aspergillus flavus was predominantly isolated. HPLC was used for evaluation of aflatoxin contamination of walnut samples. Aflatoxins G1 (AFG1), B1 (AFB1), G2 (AFG2), and B2 (AFB2) were produced by 20 isolates. AFG1 and AFB1 were being predominant at concentration ranges of 1.7-18.2 and 0-8.2 ngg^-1, respectively. Highest levels were found in one sample that was highly contaminated with Aspergillus flavus/Aspergillus parasiticus. Methyl beta cyclodextrin also was performed for detection of aflatoxigenic Aspergillus isolates. The results showed that only 31.6% (p < 0.05) of A. flavus and A. parasiticus isolates were able to produce aflatoxin. A significant difference was shown between shielded and unshielded walnut in aflatoxin contamination. The content of aflatoxin in most of the walnut samples did not reach to maximum tolerable limit for aflatoxin B1 in EU standard (p > 0.05). Thus, systematic and continues monitoring of walnuts is recommended.

MYCOLOGICAL ANALYSIS AND AFLATOXIN B1 CONTAMINANT ESTIMATION OF HERBAL DRUG RAW MATERIALS

BACKGROUND

The present study explores the fungal contamination of important herbal drug raw materials (HDRM), which are widely used in the preparation of many herbal drugs. Understanding of the microbial contamination status of HDRM is one of the important steps to ensure the safety and efficacy of herbal drugs.

MATERIALS AND METHODS

Eighteen samples of six herbal drug raw materials (HDRM) viz., Acorus calamus Linn., Cassia angustifolia Vahl., Centella asiatica (Linn.) Urban, Myristica fragrans Houtt., Tinospora cardifolia (Wild) Miers and Withania somnifera (Linn.) Dunal, were screened for fungal contamination, by employing serial dilution method. All the isolates of Aspergillus flavus were screened for their ability to produce aflatoxin B₁ (AB₁) and highly contaminated samples were subjected to AB₁ estimation by using Thin Layer Chromatography (TLC), spectrophotometric method and occurrence of Aflatoxin B₁ was confirmed by Liquid Chromatography-Mass Spectrometry analysis (LCMS).

RESULTS

A total of 302 isolates of 42 fungal species belonging to 17 genera were found in association with test the samples. More than 61% of A. flavus isolates tested positive for production of AB₁ and highest yield recorded was 5008.20 ppb from the isolates of T. cordifolia. Amongthesix highly contaminated samples three samples tested positive for AB₁. Highest AB₁ was recorded from T. cordifolia (104.19 μg/kg), followed by A. calamus (13.73 μg/kg) and M. fragrans (12.02 μg/kg).

CONCLUSION

Assessment of fungal and mycotoxin contamination should be a part of the quality check while selecting HDRM for manufacture of herbal products. Safe processing and storage practices are necessary.

Effect of Fungi Fermentation on Organoleptic Properties, Energy Content and In-vitro Multienzyme Digestibility of Cassava Products (Flour & Gari)

The present study sought to investigate the effect of fungi fermentation on the energy content, sensory quality and the digestibility (in vitro) of cassava products (flour and gari). The fungi fermented cassava products (gari and flour) were produced, by fermenting cassava mash with pure strains of some common saprophytes, namely, Aspergillus flavus, Aspergillus niger, Rhizopus oryzae and Saccharomyces spp (Baker's yeast and palm wine yeast) for 72hrs before processing into cassava flour and gari, the forms in which cassava is popularly consumed in Nigeria. Parameters determined include energy (Bomb calorimetry), digestibility (in vitro) and sensory quality by trained taste panel. The results of the study indicated that fungi fermentation of the cassava mash significantly (P < 0.05) increased the acceptability of the colour, texture, aroma and taste of the “gari”, with that of Rhizopus oryzae fermentation having the highest general acceptability. Furthermore, the results also indicated that fungi fermentation of cassava mash significantly increased (P < 0.05) the in vitro multienzyme protein digestibility of the cassava products. In view of this, fungi fermentation could be used to improve the sensory quality and protein digestibility of cassava products without any significant (P > 0.05) effect on the energy-giving role of cassava products.

Environmental distribution and genetic diversity of vegetative compatibility groups determine biocontrol strategies to mitigate aflatoxin contamination of maize by Aspergillus flavus

Maize infected by aflatoxin-producing Aspergillus flavus may become contaminated with aflatoxins, and as a result, threaten human health, food security and farmers' income in developing countries where maize is a staple. Environmental distribution and genetic diversity of A. flavus can influence the effectiveness of atoxigenic isolates in mitigating aflatoxin contamination. However, such information has not been used to facilitate selection and deployment of atoxigenic isolates. A total of 35 isolates of A. flavus isolated from maize samples collected from three agro-ecological zones of Nigeria were used in this study. Ecophysiological characteristics, distribution and genetic diversity of the isolates were determined to identify vegetative compatibility groups (VCGs). The generated data were used to inform selection and deployment of native atoxigenic isolates to mitigate aflatoxin contamination in maize. In co-inoculation with toxigenic isolates, atoxigenic isolates reduced aflatoxin contamination in grain by > 96%. A total of 25 VCGs were inferred from the collected isolates based on complementation tests involving nitrate non-utilizing (nit(-)) mutants. To determine genetic diversity and distribution of VCGs across agro-ecological zones, 832 nit(-) mutants from 52 locations in 11 administrative districts were paired with one self-complementary nitrate auxotroph tester-pair for each VCG. Atoxigenic VCGs accounted for 81.1% of the 153 positive complementations recorded. Genetic diversity of VCGs was highest in the derived savannah agro-ecological zone (H = 2.61) compared with the southern Guinea savannah (H = 1.90) and northern Guinea savannah (H = 0.94) zones. Genetic richness (H = 2.60) and evenness (E5  = 0.96) of VCGs were high across all agro-ecological zones. Ten VCGs (40%) had members restricted to the original location of isolation, whereas 15 VCGs (60%) had members located between the original source of isolation and a distance > 400 km away. The present study identified widely distributed VCGs in Nigeria such as AV0222, AV3279, AV3304 and AV16127, whose atoxigenic members can be deployed for a region-wide biocontrol of toxigenic isolates to reduce aflatoxin contamination in maize.

Effects of Hydrogen Peroxide on Different Toxigenic and Atoxigenic Isolates of Aspergillus flavus

Drought stress in the field has been shown to exacerbate aflatoxin contamination of maize and peanut. Drought and heat stress also produce reactive oxygen species (ROS) in plant tissues. Given the potential correlation between ROS and exacerbated aflatoxin production under drought and heat stress, the objectives of this study were to examine the effects of hydrogen peroxide (H2O2)-induced oxidative stress on the growth of different toxigenic (+) and atoxigenic (-) isolates of Aspergillus flavus and to test whether aflatoxin production affects the H2O2 concentrations that the isolates could survive. Ten isolates were tested: NRRL3357 (+), A9 (+), AF13 (+), Tox4 (+), A1 (-), K49 (-), K54A (-), AF36 (-), and Aflaguard (-); and one A. parasiticus isolate, NRRL2999 (+). These isolates were cultured under a H2O2 gradient ranging from 0 to 50 mM in two different media, aflatoxin-conducive yeast extract-sucrose (YES) and non-conducive yeast extract-peptone (YEP). Fungal growth was inhibited at a high H2O2 concentration, but specific isolates grew well at different H2O2 concentrations. Generally the toxigenic isolates tolerated higher concentrations than did atoxigenic isolates. Increasing H2O2 concentrations in the media resulted in elevated aflatoxin production in toxigenic isolates. In YEP media, the higher concentration of peptone (15%) partially inactivated the H2O2 in the media. In the 1% peptone media, YEP did not affect the H2O2 concentrations that the isolates could survive in comparison with YES media, without aflatoxin production. It is interesting to note that the commercial biocontrol isolates, AF36 (-), and Aflaguard (-), survived at higher levels of stress than other atoxigenic isolates, suggesting that this testing method could potentially be of use in the selection of biocontrol isolates. Further studies will be needed to investigate the mechanisms behind the variability among isolates with regard to their degree of oxidative stress tolerance and the role of aflatoxin production.

Efficiency of Artemisia nilagirica (Clarke) Pamp. essential oil as a mycotoxicant against postharvest mycobiota of table grapes

BACKGROUND

In order to get a potent botanical fungicide for the management of fungal decay of table grapes, an experiment was conducted in which 20 essential oils of higher plants were screened at 0.33 µL mL(-1) against dominant fungi causing decay of table grapes, including Aspergillus flavus, A. niger and A. ochraceus. Furthermore, the minimum inhibitory/fungicidal concentration, fungitoxic spectrum and mycotoxin inhibition activity of the most potent oil were determined. The efficacy of the most potent oil in preservation of table grapes, along with organoleptic evaluation, was also carried out by storing 1 kg of grapes in the oil vapour.

RESULTS

Artemisia nilagirica oil was found to be most toxic, exhibiting 100% mycelia inhibition of all test fungi. Moreover, 0.29 µL mL(-1) A. nilagirica oil was fungistatic and 0.58 µL mL(-1) was fungicidal for all tested species of Aspergillus. The oil exhibited a broad range of fungitoxicity against other grape berry-rotting fungi. Artemisia nilagirica oil completely suppressed the growth and mycotoxin (AFB1 and OTA) secretion of aflatoxigenic and ochratoxigenic strains of Aspergillus at 1.6 µL mL(-1) . During the in vivo experiment, fumigation of 1 kg of table grapes with 200 and 300 µL dosage of A. nilagirica oil enhanced the shelf life for up to 9 days. The oil did not show any phytotoxic effect. Besides, oil application did not substantively change the sensory properties of the fruits.

CONCLUSION

Artemisia nilagirica oil can be used as an alternative botanical fungicide for the control of fruit-rotting fungi of stored grapes.

Septic arthritis of the temporomandibular joint caused by Aspergillus flavus infection as a complication of otitis externa

Septic arthritis of the temporomandibular joint (TMJ) is a very rare complication of otitis externa that can lead to ankylosis and destruction of the joint. We report the case of a 74-year-old man who developed aspergillosis of the TMJ following otitis externa. To the best of our knowledge, this is the first reported case of TMJ septic arthritis secondary to otitis externa caused by Aspergillus flavus. The patient was successfully managed with condylectomy, debridement, and drug treatment with voriconazole.

Chronic rhinosinusitis: association of recalcitrant nasal polyposis and fungal finding in polyp's single-cell suspension

In recent years fungi are favoured as origin of chronic rhinosinusitis (CRS), especially with nasal polyps (wNP). Sensitive methods for fungal detection are still absent, therefore we used NP tissue single-cell suspension for mycology investigations in patients with recalcitrant NP (rNP) that underwent functional endoscopic sinus surgery (FESS). A prospective case-series study and culture-based mycological examination were conducted in patients who underwent FESS for the first time (ft-FESS) and those with repeated FESS (re-FESS). The study was conducted in a tertiary Otorhinolaryngology Unit of Clinical Centre of Serbia. A total of 43 consecutive patients with CRSwNP underwent FESS. Culture-based mycological examination of single-cell suspension was done on 55 NPs samples. Patient's co-morbidity data were collected. Repeated FESS was observed in 19/43 (44 %) patients (re-FESS group). Asthma and aspirin intolerance were more frequent in re-FESS than in ft-FESS group (p = 0.000, p = 0.002; respectively). Fungi were detected (wF) in 10/43 (23.3 %) patients (FESSwF group), representing 13/55 culture positive NP tissue (23.6 %). Fungal presence was higher in re-FESS than in ft-FESS group (42 and 8 %, respectively; p = 0.01). Significantly longer duration of CRS was observed in FESSwF than in fungal negative patients (p = 0.033). Predominate strain was Aspergillus flavus detected in 6/10 patients. This is the first study which analysed association of fungi in single-cell suspension of NP tissue and rNP. We demonstrate significantly higher percentage of positive fungal finding in re-FESSwF than in ft-FESSwF group. The most commonly isolated species in our patients was A. flavus.

Rapid Monitoring by Quantitative Polymerase Chain Reaction for Pathogenic Aspergillus During Carpet Removal From a Hospital

Monitoring for pathogenic Aspergillus species using a rapid, highly sensitive, quantitative polymerase chain reaction technique during carpet removal in a burn unit provided data that allowed patients to be safely returned to the refloored area sooner than if only conventional culture monitoring had been used.

Disseminated Aspergillus flavus following septic arthritis in an immunocompetent patient: a case report

BACKGROUND

Aspergillosis is a rare cause of osteomyelitis and septic arthritis. Aspergillus osteomyelitis is a debilitating infection affecting both immunocompromised and immunocompetent patients. It is associated with a high incidence of morbidity and mortality. Infection with Aspergillus flavus species in the knee has been very rarely seen in the past.

CASE PRESENTATION

We present a case of septic arthritis of the knee in an Indian patient secondary to infection with Aspergillus flavus, which was earlier managed as a case of tuberculosis based on the endemicity of the condition, later leading to disseminated aspergillosis. There was no clinical feature or investigation suggesting immunocompromised state. Following knee arthrotomy, Aspergillus flavus was isolated and patient was subsequently managed with antifungals leading to recovery after three months.

CONCLUSIONS

Disseminated aspergillosis can mimic tuberculosis both clinically and radiologically. Though fungal infections affect joints rarely but they must always be ruled out to avoid later complications.

[Identification of a kojic-acid producing Aspergillus flavus F52]

OBJECTIVE

We identified an endophytic fungus of Vigna unguiculata, as well as the influence of carbon sources on the production of kojic acid by the isolated fungus.

METHODS

This kojic acid producer was identified as Aspergillus flavus F52 according to morphological characteristics and ITS region of rDNA. The metabolite of strain F52 was obtained by recrystallization, and identified as kojic acid based on the spectral data of NMR, HR-ESI/MS and IR. The fungus was cultivated in medium containing various carbon sources, and the production of kojic acid in the fermentation broth was quantified by high performance liquid chromatography.

RESULTS

The complex carbon source which was composed of glucose and sucrose was preferential, whereas the presence of lactose was not beneficial to the production of kojic acid. The content of kojic acid in the fermentation broth reached 24.44 g/L.

CONCLUSION

Aspergillus flavus F52 might be a potent producer of kojic acid for commercial use.

Comparison of expression of secondary metabolite biosynthesis cluster genes in Aspergillus flavus, A. parasiticus, and A. oryzae

Fifty six secondary metabolite biosynthesis gene clusters are predicted to be in the Aspergillus flavus genome. In spite of this, the biosyntheses of only seven metabolites, including the aflatoxins, kojic acid, cyclopiazonic acid and aflatrem, have been assigned to a particular gene cluster. We used RNA-seq to compare expression of secondary metabolite genes in gene clusters for the closely related fungi A. parasiticus, A. oryzae, and A. flavus S and L sclerotial morphotypes. The data help to refine the identification of probable functional gene clusters within these species. Our results suggest that A. flavus, a prevalent contaminant of maize, cottonseed, peanuts and tree nuts, is capable of producing metabolites which, besides aflatoxin, could be an underappreciated contributor to its toxicity.

Potential bioremediation of mercury-contaminated substrate using filamentous fungi isolated from forest soil

The use of filamentous fungi in bioremediation of heavy metal contamination has been developed recently. This research aims to observe the capability of filamentous fungi isolated from forest soil for bioremediation of mercury contamination in a substrate. Six fungal strains were selected based on their capability to grow in 25 mg/L Hg(2+)-contaminated potato dextrose agar plates. Fungal strain KRP1 showed the highest ratio of growth diameter, 0.831, thus was chosen for further observation. Identification based on colony and cell morphology carried out by 18S rRNA analysis gave a 98% match to Aspergillus flavus strain KRP1. The fungal characteristics in mercury(II) contamination such as range of optimum pH, optimum temperature and tolerance level were 5.5-7 and 25-35°C and 100 mg/L respectively. The concentration of mercury in the media affected fungal growth during lag phases. The capability of the fungal strain to remove the mercury(II) contaminant was evaluated in 100 mL sterile 10 mg/L Hg(2+)-contaminated potato dextrose broth media in 250 mL Erlenmeyer flasks inoculated with 10(8) spore/mL fungal spore suspension and incubation at 30°C for 7 days. The mercury(II) utilization was observed for flasks shaken in a 130 r/min orbital shaker (shaken) and non-shaken flasks (static) treatments. Flasks containing contaminated media with no fungal spores were also provided as control. All treatments were done in triplicate. The strain was able to remove 97.50% and 98.73% mercury from shaken and static systems respectively. A. flavus strain KRP1 seems to have potential use in bioremediation of aqueous substrates containing mercury(II) through a biosorption mechanism.

Survey of Aspergillus section Flavi presence in agricultural soils and effect of glyphosate on nontoxigenic A. flavus growth on soil-based medium

AIMS

To evaluate the cultivable mycobiota from agricultural soils exposed to pesticides, the aflatoxigenic capacity of Aspergillus section Flavi strains and the effect of glyphosate on lag phase and growth rates of native nontoxigenic Aspergillus flavus under different water potential (MPa) conditions on soil-based medium.

METHODS AND RESULTS

Culturable mycobiota analysis from different agricultural soils was performed by the surface spread method. The effect of glyphosate (0-20 mmol l(-1)) on the growth of A. flavus strains was evaluated on a soil extract solid medium. Mycobiota analysis of crop soils showed the presence of twenty-one genera of filamentous fungi. Aspergillus flavus and Aspergillus niger aggregate strains were isolated from the three soil types. Ninety-two per cent of A. flavus strains were toxigenic. In vitro assay results showed that at -0·70 MPa, a significant increase in growth rate in all strains was recorded at 5 and 20 mmol l(-1) of glyphosate. At -2·78 MPa, this parameter remained constant at all glyphosate concentrations, except in GM4 strain where an increase in growth rate was recorded with increasing pesticide concentrations. At -7·06 MPa, a significant increase in growth rate has also been observed in GM 3 strain with 5 mmol l(-1) and in GM 4 strain with 10 and 20 mmol l(-1).

CONCLUSIONS

This study showed that the imperfecti fungi Aspergillus spp., Penicillium spp., Trichoderma spp., Cladosporium spp. and Paecilomyces spp. are isolated as prevalent groups in agricultural soil exposed to pesticides, and the capacity of nontoxigenic A. flavus strains to tolerate different glyphosate concentrations under different water potential (MPa) conditions.

SIGNIFICANCE AND IMPACT OF THE STUDY

This manuscript makes a contribution to the knowledge of cultivable fungal populations from agricultural soils exposed to pesticides and the glyphosate tolerance of A. flavus strains.

Efficacy of two chemical coagulants and three different filtration media on removal of Aspergillus flavus from surface water

Aquatic fungi are common in various aqueous environments and play potentially crucial roles in nutrient and carbon cycling as well as interacting with other organisms. Species of Aspergillus are the most common fungi that occur in water. The present study was undertaken to elucidate the efficacy of two coagulants, aluminum sulfate and ferric chloride, used at different concentrations to treat drinking water, in removing Aspergillus flavus, as well as testing three different filtration media: sand, activated carbon, and ceramic granules, for their removal of fungi from water. The results revealed that both coagulants were effective in removing fungi and decreasing the turbidity of drinking water, and turbidity decreased with increasing coagulant concentration. Also, at the highest concentration of the coagulants, A. flavus was decreased by 99.6% in the treated water. Among ceramic granules, activated carbon, and sand used as media for water filtration, the sand and activated carbon filters were more effective in removing A. flavus than ceramic granules while simultaneously decreasing the turbidity levels in the test water samples. Post-treatment total organic carbon (TOC) and total nitrogen (TN) concentrations in the experimental water did not decrease; on the contrary, TN concentrations increased with the increasing dosage of coagulants. The filtration process had no effect in reducing TOC and TN in tested water.

Environmental contamination by Aspergillus spp. in laying hen farms and associated health risks for farm workers

Data on the occurrence and epidemiology of Aspergillus spp. in laying hens farms are scant. With the aims of determining levels of airborne contamination in laying hen farms and evaluating the potential risk of infection for workers and animals, 57 air samples from 19 sheds (Group I), 69 from faeces (Group II), 19 from poultry feedstuffs (Group III) and 60 from three anatomical sites (i.e. nostrils, pharynx, ears) of 20 farm workers (Group IV) were cultured. The Aspergillus spp. prevalence in samples ranged from 31.6% (Group III) to 55.5% (Group IV), whereas the highest conidia concentration was retrieved in Group II (1.2 × 10(4) c.f.u. g(-1)) and in Group III (1.9 × 10(3) c.f.u. g(-1)). The mean concentration of airborne Aspergillus spp. conidia was 70 c.f.u. m(-3) with Aspergillus fumigatus (27.3%) being the most frequently detected species, followed by Aspergillus flavus (6.3%). These Aspergillus spp. were also isolated from human nostrils (40%) and ears (35%) (P<0.05) (Group IV). No clinical aspergillosis was diagnosed in hens. The results demonstrate a relationship between the environmental contamination in hen farms and presence of Aspergillus spp. on animals and humans. Even if the concentration of airborne Aspergillus spp. conidia (i.e. 70 c.f.u. m(-3)) herein detected does not trigger clinical disease in hens, it causes human colonization. Correct management of hen farms is necessary to control environmental contamination by Aspergillus spp., and could lead to a significant reduction of animal and human colonization.

Aspergillus flavus contamination in two Portuguese wastewater treatment plants

Filamentous fungi from genus Aspergillus were previously detected in wastewater treatment plants (WWTP) as being Aspergillus flavus (A. flavus), an important toxigenic fungus producing aflatoxins. This study aimed to determine occupational exposure adverse effects due to fungal contamination produced by A. flavus complex in two Portuguese WWTP using conventional and molecular methodologies. Air samples from two WWTP were collected at 1 m height through impaction method. Surface samples were collected by swabbing surfaces of the same indoor sites. After counting A. flavus and identification, detection of aflatoxin production was ensured through inoculation of seven inoculates in coconut-milk agar. Plates were examined under long-wave ultraviolet (UV; 365 nm) illumination to search for the presence of fluorescence in the growing colonies. To apply molecular methods, air samples were also collected using the impinger method. Samples were collected and collection liquid was subsequently used for DNA extraction. Molecular identification of A. flavus was achieved by real-time polymerase chain reaction (RT-PCR) using the Rotor-Gene 6000 qPCR detection system (Corbett). Among the Aspergillus genus, the species that were more abundant in air samples from both WWTP were Aspergillus versicolor (38%), Aspergillus candidus (29.1%), and Aspergillus sydowii (12.7%). However, the most commonly species found on surfaces were A. flavus (47.3%), Aspergillus fumigatus (34.4%), and Aspergillus sydowii (10.8%). Aspergillus flavus isolates that were inoculated in coconut agar medium were not identified as toxigenic strains and were not detected by RT-PCR in any of the analyzed samples from both plants. Data in this study indicate the need for monitoring fungal contamination in this setting. Although toxigenic strains were not detected from A. flavus complex, one cannot disregard the eventual presence and potential toxicity of aflatoxins.

In vitro comparative analysis of monocrotophos degrading potential of Aspergillus flavus, Fusarium pallidoroseum and Macrophomina sp

Fungal degradation is emerging as a new powerful tool for the removal of potent neurotoxin pesticide, monocrotophos. Therefore, the present study is aimed at comparative characterization of monocrotophos degrading ability of three different fungal strains. Fungal strains were isolated from local agricultural soil by enrichment culture method, screened by gradient culture and identified as Aspergillus flavus, Fusarium pallidoroseum and Macrophomina sp. Growth kinetics revealed a direct positive influence of monocrotophos on the viability of fungal isolates. Fungal degradation was studied in phosphorus free liquid culture medium supplemented with 150 mg L(-1) concentration of monocrotophos for a period of 15 days under optimized culture conditions. Degradation of MCP followed first order kinetics with kdeg of 0.007, 0.002 and 0.005 day(-1) and half life (t1/2) of 4.21, 12.64 and 6.32 days for A. flavus, F. pallidoroseum and Macrophomina sp. respectively. To the best of our knowledge, it is the first report signifying the potential of monocrotophos degradation by Fusarium and Macrophomina sp. The results were further confirmed by HPTLC and FTIR which indicates disappearance of monocrotophos by hydrolytic cleavage of vinyl phosphate bond. Degradation of monocrotophos by fungal isolates was accompanied by the release of extracellular alkaline phosphatases, inorganic phosphates and ammonia. The overall comparative analysis followed the order of A. flavus > Macrophomina sp. > F. pallidoroseum. Therefore, it could be concluded from the study that these three different fungal strains could be effectively used as a potential candidate for the removal of monocrotophos from contaminated sites.

Clinical experience in invasive fungal infections: multiple fungal infection as the first presentation of HIV

Fungal infections constitute an important cause of morbidity and mortality in HIV-infected patients. The authors describe the case of a 40-year-old healthy male patient with a 2-month history of fever, shivers, asthenia and anorexia, who had lost weight during the past 6 months. Laboratory investigations revealed a positive HIV screening. Computed tomography scans of the chest and abdomen showed thoracic and lumbo-aortic adenopathies. Cryptococcus neoformans was isolated from cultures of blood, bone marrow, cerebrospinal fluid and from material obtained by transbronchial biopsy. Moreover, Cryptococcus spp. were seen in the lymph node biopsy. Pneumocystis jirovecii was isolated from bronchoalveolar lavage, whereas Aspergillus fumigatus and Aspergillus flavus were detected in material from a transbronchial biopsy. The patient initially received treatment with sulfamethoxazole plus trimethoprim and amphotericin B, which resulted in a substantial clinical improvement. After the diagnosis of invasive aspergillosis, amphotericin B was replaced by voriconazole as antifungal therapy and antiretroviral therapy was added. The simultaneous occurrence of three different infectious diseases-disseminated cryptococcosis, invasive pulmonary aspergillosis and Pneumocystis jirovecii pneumonitis-in a HIV-infected patient is extremely rare and there is no doubt that both early diagnosis and treatment are crucial for the patient's chances of survival.

Antifungal action of Pichia anomala against aflatoxigenic Aspergillus flavus and its application as a feed supplement

BACKGROUND

The disastrous problem of animal feed contamination by mycotoxigenic fungi continues to challenge researchers and health overseers worldwide. With the aim of preventing Aspergillus flavus growth in vitro and in corn feed, the yeast Pichia anomala was examined as a biocontrol agent.

RESULTS

The yeast strain could efficiently prohibit the growth of A. flavus. P. anomala was able to produce exo-chitinase and β-1,3-glucanase which could be suggested as a mode of action for its antifungal activity. Scanning electron microscopy of cultured P. anomala with fungal hypha revealed that A. flavus was colonised by the biocontrol yeast which subsequently led to complete hyphal lysis and deterioration. The supplementation with of P. anomala cells, as a protein source, led to an obvious increase in animals' weight gain and protein content in feed grain. Moreover, after consumption of P. anomala-supplemented feed, there was a remarkable decrease in the mortality rate among fed animals.

CONCLUSION

P. anomala could be strongly recommended as a biocontrol agent against A. flavus which contaminates animal feed. Furthermore, the application of yeast cells, as a feed additive, proved its efficiency for escalating protein content and enhancing animal performance.

Renal aspergillosis secondary to renal intrumentation in immunocompetent patient

Primary renal aspergillosis is a rare urological entity and immune-compromised persons are commonly prone to it. The clinical presentation resembles that of usual bacterial pyelonephritis. We report a case of localised unilateral renal aspergillosis with obstructive uropathy (hypoplastic contralateral kidney) in a young man, occurring after the endoscopic removal of impacted right upper ureteric calculus in a non-immunocompromised patient. In view of deranged renal function, he was initially managed by percutaneous nephrostomy and DJ stent removal followed by oral voriconazole therapy for 3 weeks. He responded well to the treatment. Subsequently, the patient was free of renal colic, fever and urine culture negative for Aspergillus.

Abiotic factors and their interactions influence on the co-production of aflatoxin B(1) and cyclopiazonic acid by Aspergillus flavus isolated from corn

The objectives of this study were i) to determine the effects of the interactions of water activity, temperature and incubation time on the co-production of AFB1 and CPA by isolates of Aspergillus flavus with different profile of mycotoxin production and ii) to identify the aW and temperature limiting conditions for the production of both mycotoxins. Fungi used in this study were selected because they belonged to different chemotypes: chemotype I (AFB1+/CPA+), III (AFB1+/CPA-) and IV (AFB1-/CPA+), respectively. Two culture media were used; Czapek yeast agar (CYA) and corn extract agar (CEM), at different incubated temperatures (10-40 °C) and aW levels (0.80-0.98). AFB1 and CPA production were analyzed after 7, 14, 21 and 28 days of incubation. Significant differences were observed with respect to mycotoxin production depending on the media evaluated. The AFB1 production occurred more favorably on CYA while the highest CPA concentrations were recorded on CEM. Within the range of aW evaluated in this study, 0.83 was the limiting level for both toxins production. The optimum conditions for AFB1 production occurred at 0.96 aW and 30 °C after 21 days of incubation, regardless of the media and isolate. Although different amounts of toxins were produced in each medium, the limiting and optimum conditions for their production were similar in both. No differences in the response of the three isolates to the abiotic factors discussed were observed despite belonging to different chemotypes. The determination of the thresholds of mycotoxins co-production, especially in the case of data obtained with the corn extract medium can be useful to avoid the conditions conducive to co-occurrence of these mycotoxins in corn.

Equisetum arvense hydro-alcoholic extract: phenolic composition and antifungal and antimycotoxigenic effect against Aspergillus flavus and Fusarium verticillioides in stored maize

BACKGROUND

Maize is a very important cereal for human and animal diet, but it can be contaminated by moulds and their mycotoxins. On the other hand, natural plant products with antimicrobial properties could possibly used to control mycotoxigenic fungi in foods and feeds. In this study, Equisetum arvense extract was tested for the efficacy on Aspergillus section Flavi and Fusarium section Liseola growth. Natural contaminated maize was used in this study and extract was added under different water activities (a(w)) - 0.90 and 0.95 - for Aspergillus section Flavi and Fusarium section Liseola, respectively. Moulds were inoculated in maize and incubated during 30 days.

RESULTS

We confirm that E. arvense extract may be effective for the inhibition of Aspergillus section Flavi in maize with high levels of this mould. Moreover, this extract showed a good inhibition of growth on Fusarium section Liseola levels. Aflatoxin and fumonisin production was not affected by the extract.

CONCLUSIONS

E. arvense extract could be an alternative to synthetic fungicides to control maize mycobiota level in moist grain.

Aspergillus meningitis: a rare clinical manifestation of central nervous system aspergillosis. Case report and review of 92 cases

OBJECTIVES

To describe the pathogenesis, clinical presentation, cerebrospinal fluid findings and outcome of Aspergillus meningitis, meningoencephalitis and arachnoiditis.

METHODS

A case of Aspergillus meningitis is described. A comprehensive review of the English-language literature was conducted to identify all reported cases of Aspergillus meningitis described between January 1973 and December 2011.

RESULTS

Ninety-three cases (including the one described herein) of Aspergillus meningitis were identified. Fifty-two (55.9%) were in individuals without any predisposing factor or known causes of immunosuppression. Acute and chronic meningitis was diagnosed in 65.6% of patients and meningoencephalitis in 24.7% of them with the remaining presenting with spinal arachnoiditis and ventriculitis. Cerebrospinal fluid cultures for Aspergillus spp. were positive in about 31% of cases and the galactomannan antigen test in 87%. Diagnosis during life was achieved in 52 patients (55.9%) with a case fatality rate of 50%. The overall case fatality rate was 72.1%.

CONCLUSIONS

Aspergillus meningitis may occur in both immunocompetent and immunocompromised patients and run an acute or chronic course. The findings of this systematic review extend the information on this life-threatening infection and could assist physicians in achieving an improved outcome.

Costochondritis caused by Aspergillus flavus following cardiac surgery

Mediastinitis is an infrequent complication after coronary artery bypass graft (CABG) that is associated with prolonged intensive care unit and hospital stay, and increased early and late morbidity and mortality. Patients with mediastinitis have an osteoporotic, fragile, and broken sternum. All foreign bodies as well as infected tissue should be removed. Osteomyelitis of sternum often perseveres after debridement for mediastinitis. In this report, we describe an unusual case of costochondritis caused by aspergillosis following off pump CABG surgery in a male patient in Yazd-Iran.