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.

Aspergillus flavus, mainly causing fungal rhinosinusitis in Sudan, poses health risks due to aflatoxin production. This study revealed diverse levels of aflatoxin and gene expression of clinical isolates by pheno- and genotypic methods, emphasizing the need for vigilant monitoring in the region.

Molecular and aflatoxigenicity analyses of Aspergillus flavus isolates indigenous to grain corn in Malaysia; potentials for biological control.

AIMS: The present work aimed to distinguish the indigenous Aspergillus flavus isolates obtained from the first (pioneer) grain corn farms in Terengganu, Malaysia, into aflatoxigenic and non-aflatoxigenic by molecular and aflatoxigenicity analyses, and determine the antagonistic capability of the non-aflatoxigenic isolates against aflatoxigenic counterparts and their aflatoxin production in vitro. METHODS AND RESULTS: Seven A. flavus isolates previously obtained from the farms were characterized molecularly and chemically. All isolates were examined for the presence of seven aflatoxin biosynthesis genes, and their aflatoxigenicity was confirmed using high performance liquid chromatography with fluorescence detector. Phylogenetic relationships of all isolates were tested using ITS and ß-tubulin genes. Of the seven isolates, two were non-aflatoxigenic, while the remaining were aflatoxigenic based on the presence of all aflatoxin biosynthesis genes tested and the productions of aflatoxins B1 and B2. All isolates were also confirmed as A. flavus following phylogenetic analysis. The indigenous non-aflatoxigenic isolates were further examined for their antagonistic potential against aflatoxigenic isolates on 3% grain corn agar. Both non-aflatoxigenic isolates significantly reduced AFB1 production of the aflatoxigenic isolates. CONCLUSION: The indigenous non-aflatoxigenic A. flavus strains identified in the present work were effective in controlling the aflatoxin production by the aflatoxigenic A. flavus isolates in vitro and can be utilized for in situ testing.

[Aspergillus flavus/oryzae Arthritis of the Knee Joint: First Case in Türkiye]. / Diz Ekleminde Gelisen Aspergillus flavus/oryzae Artriti: Türkiye'de Ilk Olgu.

Aspergillus species are common hyphal fungi. In addition to allergies and mycotoxicosis, Aspergillus species can cause various infections known as aspergillosis. Aspergillosis of the respiratory tract, central nervous system, skin and soft tissues is well described. However, musculoskeletal infections due to invasive aspergillosis are not well described. Fungal joint infection due to invasive aspergillosis is a rare form of septic arthritis. In this case report, a patient who admitted to our hospital for liver transplantation and developed knee joint arthritis caused by Aspergillus flavus/Aspergillus oryzae during this process was presented. A 28-year-old male patient with autoimmune hepatitis was admitted to hospital with decompensated liver cirrhosis and encephalopathy. The patient, who was awaiting an emergency liver transplant, developed pain, swelling and limitation of movement in his right knee and appropriate consultations and tests were requested. Three joint fluid cultures taken one day apart and nine days later were positive for fungal growth. Macroscopic examination of the mould growth and microscopic examination with lactophenol cotton blue suggested a species belonging to the A.flavus complex and the isolate was identified as A.flavus/A.oryzae by matrix-assisted laser desorption/ionisation mass spectrometry (MALDI-TOF MS) (EXS 2600, Zybio, China). As a result of ITS gene sequencing, the species was determined to be A.oryzae. As cases have been reported where A.flavus and A.oryzae species could not be distinguished by ITS gene sequencing, the pathogen was defined as A.flavus/oryzae. The patient died of liver disease during treatment with amphotericin B. There are few cases of arthritis caused by Aspergillus species in the literature. Aspergillus species found in joint infections are, Aspergillus fumigatus, A.flavus, Aspergillus niger and Aspergillus terreus species complexes, in order of frequency. A.flavus and A.oryzae are closely related. They are difficult to distinguish by conventional methods, MALDI-TOF MS or ITS region sequencing, which is commonly used for genus/species identification in fungi. The number of Aspergillus arthritis cases is low and the identification methods applied to the species reported as causative agents in most studies can identify at the species complex level. In addition, it can be assumed that species not previously reported as causative agents may be encountered as a result of developments in identification methods. In the few publications in the literature where A.flavus complex was reported as the causative agent of joint infections, it seems possible that some of the agents may be A.flavus and some may be A.oryzae, since the agents were identified at the complex level. There are a limited number of cases in the literature where A.oryzae is the causative agent, particularly in the respiratory tract. A PubMed search using the keywords "A.oryzae infections, arthritis, osteomyelitis" did not reveal any literature on joint infections caused by A.oryzae.

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.

Aspergillus flavus originated pure compound as a potential antibacterial.

PROBLEM BACKGROUND: Penicillin was the first and most famous fungal secondary metabolite used as broad spectrum antibiotic that revolutionarised pharmaceutical research and also saved millions of lives. The over optimistic belief in 1967 that sufficient antibiotics had been discovered to defeat infectious diseases was quickly crashed with the appearance of multidrug resistant (MDR) bacteria in 1990s. This has posed a serious threat to mankind. Although scientists are making efforts to synthesize and discover new antibiotics there are not enough new drugs in pharmaceutical pipeline to beat the pace at which MDR bacteria are emerging. In view of this there is an urgent and serious medical need for new bioactive compounds to be discovered to treat infections caused by MDR pathogens. The present study is aimed to investigate the antibacterial potential of Aspergillus flavus originated compounds that may act as drug leads to treat future infections. METHODOLOGY: Among the 6 isolated fungal strains from the rhizosphere of Mentha piperetta, one was processed for isolation of secondary metabolites on the basis of preliminary antibacterial testing. Observation of morphological and microscopic features helped in identification of the fungal strain as Aspergillus flavus. Potato Dextrose Agar (PDA) medium was used for fungal growth while Czapec Yeast Broth (CYB) medium was used for production of fungal metabolites. Column chromatography technique was utilized for purification of compound from crude fungal extract and the mass of the compound was determined using Liquid Chromatography Mass Spectrometry (LCMS) method. Structure elucidation of the pure compound was performed using 500 Varian Nuclear Magnetic Resonance (NMR) machine. Docking was performed using Glide SP algorithm. Agar well diffusion method was used to determine the invitro antibacterial potential of the compound against two MDR bacterial strains i.e. Staphylococcus aureus and Proteus vulgaris. For this a total of 4 dose concentrations i.e. (100, 250, 500, 1000 µg mL- 1) of the compound were prepared and applied to bacterial strains on Mueller Hinton agar using tetracycline as control. RESULTS: The chemical name of the purified compound from A. flavus was determined as (2E)-3-[(3S, 4R)-8-hydroxy-3, 4-dimethyl-1-oxo-3, 4-dihydro-1H-2- benzopyran-7-yl] prop-2-enoic acid with the formula C14H14O5 and exact mass of 262.08. The in-Silico analysis showed that this compound has the potential to inhibit the binding pocket of S. aureus TyrRS (1JII) with docking score of - 8.67 Kcal mole- 1. The results obtained from invitro experiments were encouraging as at 1000 µg mL- 1 the compound showed 58.8% inhibition against S. aureus and 28% inhibition against P. vulgaris. CONCLUSIONS: The pure compound with formula C14H14O5 and exact mass of 262 exhibited antibacterial potential both insilico and invitro against both Gram negative and Gram positive bacteria. The compound was more active against S. aureus in comparison to P. vulgaris. From the obtained results it is concluded that this compound can be used as potent antibacterial candidate but further studies will be needed prior to its use as antibiotic.

Antifungal susceptibility profile and molecular identification of Cyp51C mutations in clinical and environmental isolates of Aspergillus flavus from Argentina.

BACKGROUND: The emergence of azole resistance in non-fumigatus Aspergillus strains is on the raise. OBJECTIVES: To study the susceptibility profiles and the molecular mechanisms of azole resistance of environmental and clinical strains of Aspergillus flavus from Argentina. METHODS: Thirty-five A flavus isolates (18 from soybean seeds and chickpea seeds and 17 from the clinic) were analysed for amphotericin B and azole resistance using the standard microbroth dilution method according to CLSI M38-A2 guidelines. Sequencing analysis of the cyp51 genes was conducted in those isolates displaying high MICs values to itraconazole, voriconazole and/or posaconazole. RESULTS: Among the environmental isolates, 33.3% of them showed high MIC values for at least one triazole whereas 23.5% of the clinical isolates displayed high MIC values for amphotericin B. Point mutations in the Cyp51C gene were recorded in most environmental isolates with non-wild-type MIC values. CONCLUSIONS: Susceptibility differences among environmental A flavus isolates might suggest the possibility of native resistance to certain triazole antifungals used in the clinic. To the best of our knowledge, this is the first report of antifungal screening of environmental strains of A flavus in soybean seeds and chickpea seeds from Argentina that showed increased resistance to voriconazole and itraconazole in comparison to clinical strains.

Proven Aspergillus flavus pulmonary aspergillosis in a COVID-19 patient: A case report and review of the literature.

Severe COVID-19 patients complicated with aspergillosis are increasingly reported. We present a histopathological proven case of fatal COVID-19-associated pulmonary aspergillosis (CAPA), due to Aspergillus flavus. This report and existing published literature indicate diagnostic challenges and poor outcomes of CAPA in ICU patients.

Deciphering the origin of Aspergillus flavus NRRL21882, the active biocontrol agent of Afla-Guard®.

Single nucleotide polymorphisms (SNPs) of genome sequences of eight Aspergillus flavus and seven Aspergillus oryzae strains were extracted with Mauve, a multiple-genome alignment programme. A phylogenetic analysis with sequences comprised of concatenated total SNPs by the unweighted pair group method with arithmetic mean (UPGMA) of MAFFT adequately separated them into three groups, A. flavus S-morphotype, A. flavus L-morphotype and A. oryzae. Divergence time inferred for A. flavus NRRL21882, the active agent of the biocontrol product Afla-Guard® , and S-morphotype was about 5·1 mya. Another biocontrol strain, A. flavus AF36, diverged from aflatoxigenic L-morphotype about 2·6-3·0 mya. Despite the close relatedness of A. oryzae to A. flavus, A. oryzae strains likely evolved from aflatoxigenic Aspergillus aflatoxiformans (=A. parvisclerotigenus). A survey of A. flavus populations implies that prior Afla-Guard® applications are associated with prevalence of NRRL21882-type isolates in Mississippi fields. In addition, a few NRRL21882 relatives were identified. A. flavus Og0222, a biocontrol ingredient of Aflasafe™, was verified as a NRRL21882-type strain, having identical sequence breakpoints that led to deletion of aflatoxin and cyclopiazonic acid gene clusters. A similar UPGMA analysis suggests that the occurrence of NRRL21882-type strains is a more recent event.

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.

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.

Aspergillus flavus malignant external otitis in a diabetic patient: case report and literature review.

PURPOSE: Malignant external otitis is an aggressive and potentially life-threatening infection. This rare disorder is typically caused by Pseudomonas aeruginosa and affects almost exclusively elderly diabetic patients. However, fungal malignant external otitis have been identified, especially in immunocompromised hosts. METHODS: We report a rare case of invasive malignant external otitis caused by Aspergillus flavus in a diabetic patient without other underlying immunosuppression. A review of Aspergillus spp. malignant external otitis since voriconazole became the first line for invasive aspergillosis was performed. RESULTS: A 72-year-old man with diabetes mellitus developed invasive malignant external otitis with a vascular involvement. The patient was treated with empiric courses of antibiotics until a fungal infection was diagnosed. Proven Apsergillus infection was based on histopathological examination and isolation of A. flavus from culture of osteo-meningeal biopsies. Despite optimal antimicrobial therapy with voriconazole, the patient presented with cerebral infarction in the setting of an angioinvasive fungal infection leading to a fatal outcome. From a review of the literature, we found 39 previously published cases of proven Aspergillus spp. malignant external otitis treated with new triazoles. CONCLUSION: Given our experience and the literature review, a fungal etiology should be considered early in the course of malignant external otitis unresponsive to a conventional broad spectrum antibiotic therapy, with the need for a tissue biopsy to confirm the diagnosis.

The microbial flora of clinically infected cutaneous metastases: a retrospective study.

Symptomatic cutaneous metastases are associated with discharge, malodour, pruritus and pain, all of which may negatively impact quality of life and cutaneous health. We conducted a retrospective chart review of patients referred to the Dermatology Service at Memorial Sloan Kettering Cancer Center between August 2006 and June 2015, and characterized the microbial flora and antimicrobial management of cutaneous metastases in 64 patients. We detected pathogenic and/or opportunistic bacteria in 50% of skin lesions. The most commonly isolated organisms were Staphylococcus aureus and Pseudomonas aeruginosa. Patients treated with oral antibiotics, alone or in combination with topical agents, had a statistically significant better improvement in infectious symptoms than those treated without oral antibiotics. Our findings suggest that the normal skin microbial flora is disrupted in patients with symptomatic skin metastases. Oral antibiotics may provide benefit when used as first-line therapy for infected skin lesions in patients with symptomatic cutaneous metastases.

Percutaneous transforaminal endoscopic discectomy for the treatment of lateral recess stenosis secondary occurred the discal fungus infection.

BACKGROUND: This is a case of lateral recess stenosis secondary occurred the discal fungus infection treated with percutaneous transforaminal endoscopic discectomy (PTED). There has been no relevant reports before. CASE PRESENTATION: A 49-year-old patient who had taken itraconazole for 13 months for lateral recess stenosis secondary occurred the discal fungus infection complained of gradually worsening radiating pain and numbness in the back and inguinal and inner thigh region of right side. In order to relieve the radiating neuralgia and reduce the damage to spinal stability, the minimally invasive PTED was performed.The patient's prognosis was assessed using Oswestry Disability Index (ODI) and Visual Analogue Scale (VAS). During the follow-up, the patient's ODI and VAS scores were decreased significantly. The radiating pain in the inguinal and inner thigh region of right side were significantly alleviated and the discomfort caused by lower back instability was improved by plaster vest. DISCUSSION AND CONCLUSION: PTED not only avoids further damage to the stability of the lumbar spine, but also effectively relieves the symptoms of leg neuroradialgia caused by lateral recess stenosis secondary occurred the discal fungus infection.

Isolation and molecular identification of Aspergillus flavus and the study of its potential for malathion biodegradation in water.

In spite of the fact that pesticides enhanced the quality and yield of the agricultural production however do have certain serious effects on the environment. This study was carried out for isolation and molecular identification of microorganisms from water for malathion biodegradation in aquatic system. PCR analysis was used for identification of the isolated fungus. The growth kinetics of A. flavus in the presence of malathion under different environmental factors (pH, temperature and malathion concentration) were evaluated. Furthermore, the degradation kinetics of malathion by A. flavus in aqueous media under different environmental factors was evaluated. The isolated microorganism was identified as A. flavus with respect to it relation to the data from the gene bank and the lowest nucleotide diversity value between the tested isolate and A. flavus. The identified isolate grew successfully in a media supplemented with malathion much faster than without it. Hundred percent of malathion initial concentration was degraded within 36 days of incubation with A. flavus. The temperature of 30 °C, pH value of 7 and malathion initial concentration of 5 mg/l were the optimum conditions of A. flavus for growth and degradation of malathion. Bioremediation of malathion residues in water using A. flavus isolate are promising and considered the first report.

Antimicrobial activity of green silver nanoparticles from endophytic fungi isolated from Calotropis procera (Ait) latex.

Endophytes, a potential source of bioactive secondary metabolites, were isolated from the widely used medicinal plant Calotropis procera Ait. Approximately 675 segments from 15 Calotropis procera plants and 15 latex samples were assessed for the presence of endophytic fungi. Finally, eight fungal species were isolated and identified based on their macro- and micro-morphology. The endophytic fungal filtrates were screened for their antimicrobial activity against 11 important pathogenic micro-organisms. The filtrates of nanoparticles were from three of the eight isolated endophytic fungi, namely, Penicillium chrysogenum, Aspergillus fumigatus and Aspergillus flavus, and were highly effective against the tested bacteria, while the remaining endophytic fungal filtrates displayed low activity.

Carbohydrate, glutathione, and polyamine metabolism are central to Aspergillus flavus oxidative stress responses over time.

BACKGROUND: The primary and secondary metabolites of fungi are critical for adaptation to environmental stresses, host pathogenicity, competition with other microbes, and reproductive fitness. Drought-derived reactive oxygen species (ROS) have been shown to stimulate aflatoxin production and regulate in Aspergillus flavus, and may function in signaling with host plants. Here, we have performed global, untargeted metabolomics to better understand the role of aflatoxin production in oxidative stress responses, and also explore isolate-specific oxidative stress responses over time. RESULTS: Two field isolates of A. flavus, AF13 and NRRL3357, possessing high and moderate aflatoxin production, respectively, were cultured in medium with and without supplementation with 15 mM H2O2, and mycelia were collected following 4 and 7 days in culture for global metabolomics. Overall, 389 compounds were described in the analysis which encompassed 9 biological super-pathways and 47 sub-pathways. These metabolites were examined for differential accumulation. Significant differences were observed in both isolates in response to oxidative stress and when comparing sampling time points. CONCLUSIONS: The moderately high aflatoxin-producing isolate, NRRL3357, showed extensive stimulation of antioxidant mechanisms and pathways including polyamines metabolism, glutathione metabolism, TCA cycle, and lipid metabolism while the highly aflatoxigenic isolate, AF13, showed a less vigorous response to stress. Carbohydrate pathway levels also imply that carbohydrate repression and starvation may influence metabolite accumulation at the later timepoint. Higher conidial oxidative stress tolerance and antioxidant capacity in AF13 compared to NRRL3357, inferred from their metabolomic profiles and growth curves over time, may be connected to aflatoxin production capability and aflatoxin-related antioxidant accumulation. The coincidence of several of the detected metabolites in H2O2-stressed A. flavus and drought-stressed hosts also suggests their potential role in the interaction between these organisms and their use as markers/targets to enhance host resistance through biomarker selection or genetic engineering.

Could aflatoxin B1 production by Aspergillus flavus affect the severity of keratitis: an experience in two tertiary health care centers, Egypt.

To investigate the expression of AFB1 gene in isolates obtained from corneal scrapping samples from keratitis patients and to correlate the quantity of AFB1 to the severity of keratitis. An observational study was undertaken in Medical Microbiology and Immunology department, Mansoura University, Egypt, over corneal scrapping samples that were cultured aiming to isolate fungal causes of infective keratitis followed by AFB1 gene detection in Aspergillus flavus isolates by nested PCR then quantitation of the toxin by TLC. Out of 843 corneal scrapping samples collected from patients with infective keratitis, positive fungal growth was identified in 277 cases (32.9%). A. flavus was the commonest fungal agent isolated in 93 cases (33.6%). The AFB1 toxin-encoding gene was detected in 63.4% of A. flavus isolates. There was a positive correlation between the quantity of produced AFB1 toxin and the degree of severity of keratitis (P value < 0.0001*). Aspergillus flavus was the most common cause of fungal keratitis, with the AFB1 toxin-encoding gene detected in more than half of the isolates. A significant correlation between the degree of severity of keratitis and the quantity of produced AFB1 toxin was detected. Therefore, exploring presence or absence of AFB1 toxin is important for the clinicians in their diagnostic assessment and selection of proper treatment choices.

Genome-wide nucleotide variation distinguishes Aspergillus flavus from Aspergillus oryzae and helps to reveal origins of atoxigenic A. flavus biocontrol strains.

AIMS: To use genome-wide single nucleotide polymorphisms (total SNPs) to develop a molecular method for distinguishing Aspergillus flavus and Aspergillus oryzae. METHODS AND RESULTS: Thirteen A. flavus and eleven A. oryzae genome sequences were obtained from the National Center for Biotechnology Information. These sequences were analysed by Mauve, a multiple-genome alignment program, to extract total SNPs between isolates of A. flavus, A. oryzae, or the two species. Averages of total SNPs of A. flavus isolates belonging to the same sclerotial morphotype (L-type = 178 952 ± 14 033; S-type = 133 188 ± 16 430) and A. oryzae isolates (152 336 ± 49 124) were consistently lower than those between the morphotypes and between the two species. Averages of total SNPs for L-type vs S-type (300 116 ± 1562) and S-type A. flavus vs A. oryzae (301 797 ± 4123) were similar but were 36% greater than that of L-type A. flavus vs A. oryzae (226 240 ± 10 779). Based on the devised criterion, ATCC 12892, Aspergillus oryzae (Ahlburg) Cohn, which had an averaged total SNPs 10-fold greater than that of other A. oryzae isolates, was determined to be close to Aspergillus parasiticus. Atoxigenic A. flavus field isolates, WRRL1519 and NRRL35739, were shown to more closely resemble A. oryzae than toxigenic L-type A. flavus. Biocontrol strains AF36 and K49 were genetically close to toxigenic L-type A. flavus. NRRL21882, the active agent of the commercialized biocontrol product Afla-Guard® GR, was genetically distant from all other A. flavus isolates. CONCLUSIONS: The close genetic relatedness between A. flavus and A. oryzae was confirmed and the evolutionary origins of atoxigenic A. flavus biocontrol strains were revealed. SIGNIFICANCE AND IMPACT OF THE STUDY: The study provides a greater understanding of genome similarity and dissimilarity between A. flavus and A. oryzae. The method can be an auxiliary technique for identifying A. flavus, A. oryzae.

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 (RP ) 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.

Identification of Aspergillus flavus and aflatoxin in home mix layer poultry feed in relation to seasons in Karachi, Pakistan.

Fungal toxins in feed are leading issue in poultry industry causing a detrimental effect on the performance and health of poultry. The study was carried out to determine the incidence and concentration of the aflatoxins and their major producer Aspergillus flavus in home mix layer poultry feed in respect of seasonal variation throughout the year. A total of (n = 204) home mix poultry layer feed samples were analyzed for the isolation of fungi. The isolates were initially screened through colony morphology and microscopic examination. However, aflatoxin concentration was determined by ELISA. Revealed results indicated that, the highest percentage of A. flavus was found during the months of June to August 50/54 (92.5%) followed by September to November 43/65 (66.1%), March to May 21/40 (52.5%), and December to February 18/45 (40%). As a whole, the incidence was recorded 132/204 (64.7%). Moreover, of the 132 samples, 41 (31%) were exceeded in respect of aflatoxin contamination from the legal limit (20 µg/kg) imposed by Food Drug Association (FDA). Statistically, the growth of A. flavus and aflatoxin production was found significantly different in respect of seasonal variation. As highest total viable fungal count (9.9 × 104 CFU/g) and aflatoxin level (72.27 µg/kg) were recorded during the months of June to August and lowest in December to February. Consequently, instantaneous essential control measures are demanded regarding appropriate storage and adequate drying in post-harvesting season. Along with surveillance plans and austere regulations for monitoring the aflatoxin contents for the wellbeing of consumers.