Flavus Infection Research Articles

High-density SNP map facilitates fine mapping of QTLs and candidate genes discovery for Aspergillus flavus resistance in peanut (Arachis hypogaea).

Two novel resistant QTLs mapped and candidate genes identified for Aspergillus flavus resistance in cultivated peanut using SLAF-seq. Aflatoxin contamination in peanuts caused by Aspergillus flavus is a serious food safety issue for human health around the world. Host plant resistance to fungal infection and reduction in aflatoxin are crucial for mitigating this problem. Identification of the resistance-linked markers can be used in marker-assisted breeding for varietal development. Here we report construction of two high-density genetic linkage maps with 1975 SNP loci and 5022 SNP loci, respectively. Two consistent quantitative trait loci (QTL) were identified as qRAF-3-1 and qRAF-14-1, which located on chromosomes A03 and B04, respectively. QTL qRAF-3-1 was mapped within 1.67cM and had more than 19% phenotypic variance explained (PVE), while qRAF-14-1 was located within 1.34cM with 5.15% PVE. While comparing with the reference genome, the mapped QTLs, qRAF-3-1 and qRAF-14-1, were located within a physical distance of 1.44 Megabase pair (Mbp) and 2.22 Mbp, harboring 67 and 137 genes, respectively. Among the identified candidate genes, six genes with the same function were found within both QTLs regions. In addition, putative disease resistance RPP13-like protein 1 (RPP13), lipoxygenase (Lox), WRKY transcription factor (WRKY) and cytochrome P450 71B34 genes were also identified. Using microarray analysis, genes responded to A. flavus infection included coding for RPP13, pentatricopeptide repeat-containing-like protein, and Lox which may be possible candidate genes for resistance to A. flavus. The QTLs and candidate genes will further facilitate marker development and validation of genes for deployment in the molecular breeding programs against A. flavus in peanuts.

Antioxidants and immune responses, resistance to Aspergilus flavus infection, and growth performance of Nile tilapia, Oreochromis niloticus, fed diets supplemented with yeast, Saccharomyces serevisiae

Yeast, Saccharomyces cerevisiae, is a single cell fungus, which contains various immune-stimulant compounds such as β-glucans, nucleic acids, oligosaccharides and chitin among others. So, it has been used as a probiotic in aqua-feeds. A feeding trial was conducted to examine the effects of dietary yeast supplementation on growth, hematological, antioxidant, and immune biomarkers of Nile tilapia, Oreochromis niloticus as well as its resistance to pathogenic fungus Aspergilus flavus infection. Five isonitrogenous diets containing 0 (control), 2, 4, 6, and 10 g yeast/kg diet were formulated and fed to triplicate groups of fish (2.4 ± 0.14 g) for 8 weeks. After that, fish were intraperitoneally injected with pathogenic fungus, A. flavus and observed for any clinical signs and mortality for 14 days. It is noticed that dietary yeast levels linearly and quadratically enhanced (P < 0.001) the growth performance of Nile tilapia and the feed intake but not feed conversion ratio. Also, dietary yeast administration to fish significantly improved (P > 0.05) their intestinal villi length/width and absorption area. Linearly and quadrically increases were observed in counts of red blood cells, white blood cells, and platelets as well as hemoglobin and hematocrit values accompanied with linear and quadric decreases in heterocytes and monocytes percentages due to dietary yeast administration to Nile tilapia. Further linear and quadric (P < 0.001) enhancements of superoxide dismutase, catalase, and glutathione peroxidase activities as well as activities of respiratory burst and lysozyme accompanied with linear and quadric reduction (P < 0.001) in the malondialdehyde level along the yeast supplementation levels. After A. flavus challenge, highest mortality (36.7 %) was observed in fish fed the control diet, while no mortality was obtained in fish fed 6–10 g yeast/kg diet. The present study showed that dietary yeast, S. serevisiae, strongly improved growth, hematological, antioxidant, and immune responses of Nile tilapia and its resistance against pathogenic fungus A. flavus infection with an optimum inclusion level of 6 g/kg diet.

Changes of Chemical Composition and Aflatoxin Content of Peanut Products as Affected by Processing Methods

&lt;div class="page" title="Page 1"&gt;&lt;div class="layoutArea"&gt;&lt;div class="column"&gt;&lt;p&gt;&lt;span&gt;Peanut production in Indonesia is predominantly used for food, thus information on nutritional aspects and aflatoxin contamination in peanuts is essential in terms of food security and safety. As changes may occur during &lt;/span&gt;&lt;/p&gt;&lt;/div&gt;&lt;div class="column"&gt;&lt;p&gt;&lt;span&gt;processing, the effects of processing methods on chemical composition and aflatoxin content in selected peanut products were studied. The dried peanut pods collected from a farmer in Ponorogo, East Java were stored for one month, and then the kernels were prepared into fried peanut (&lt;/span&gt;&lt;span&gt;kacang goreng&lt;/span&gt;&lt;span&gt;), peanut sauce (&lt;/span&gt;&lt;span&gt;sambel pecel&lt;/span&gt;&lt;span&gt;), peanut press cake (&lt;/span&gt;&lt;span&gt;bungkil kacang&lt;/span&gt;&lt;span&gt;), fried-pressed peanut (&lt;/span&gt;&lt;span&gt;bungkil kacang goreng&lt;/span&gt;&lt;span&gt;), fermented peanut press cake (&lt;/span&gt;&lt;span&gt;tempe bungkil kacang&lt;/span&gt;&lt;span&gt;), and fried peanut tempe (&lt;/span&gt;&lt;span&gt;tempe bungkil kacang goreng&lt;/span&gt;&lt;span&gt;). The trial was arranged in a randomized complete design with three replicates. ELISA method was applied for aflatoxin B&lt;/span&gt;&lt;span&gt;1 &lt;/span&gt;&lt;span&gt;analysis. The results showed that peanut kernels contained 26.3% protein (dw) and 50.4% fat (dw) with relatively low aflatoxin B&lt;/span&gt;&lt;span&gt;1 &lt;/span&gt;&lt;span&gt;content (9.1 ppb) due to low moisture level (5.6%), no &lt;/span&gt;&lt;span&gt;Aspergillus flavus &lt;/span&gt;&lt;span&gt;infection and high sound/intact kernels (73.1%). Peanuts processed into &lt;/span&gt;&lt;span&gt;tempe bungkil kacang &lt;/span&gt;&lt;span&gt;showed the highest increase in protein content, followed by &lt;/span&gt;&lt;span&gt;tempe bungkil kacang goreng&lt;/span&gt;&lt;span&gt;, &lt;/span&gt;&lt;span&gt;bungkil kacang&lt;/span&gt;&lt;span&gt;, and &lt;/span&gt;&lt;span&gt;bungkil kacang goreng&lt;/span&gt;&lt;span&gt;, while fat contents decreased in all products. Processing into &lt;/span&gt;&lt;span&gt;kacang goreng &lt;/span&gt;&lt;span&gt;and &lt;/span&gt;&lt;span&gt;bungkil kacang goreng &lt;/span&gt;&lt;span&gt;decreased aflatoxin B&lt;/span&gt;&lt;span&gt;1 &lt;/span&gt;&lt;span&gt;by 26.4% and 41.8%, respectively, while no significant differences were noted in &lt;/span&gt;&lt;span&gt;sambal pecel &lt;/span&gt;&lt;span&gt;and &lt;/span&gt;&lt;span&gt;bungkil kacang&lt;/span&gt;&lt;span&gt;. Aflatoxin B&lt;/span&gt;&lt;span&gt;1 &lt;/span&gt;&lt;span&gt;increased two-fold during the preparation of &lt;/span&gt;&lt;span&gt;tempe bungkil kacang&lt;/span&gt;&lt;span&gt;, however it significantly decreased by 38.9% after deep-fried. Excluding peanut tempe, all peanut products contained aflatoxin B&lt;/span&gt;&lt;span&gt;1 &lt;/span&gt;&lt;span&gt;below the permitted level (15 ppb), therefore they are safe for consumption.&lt;/span&gt;&lt;/p&gt;&lt;/div&gt;&lt;/div&gt;&lt;/div&gt;

Molecular and structural basis of nucleoside diphosphate kinase–mediated regulation of spore and sclerotia development in the fungus Aspergillus flavus

The fundamental biological function of nucleoside diphosphate kinase (NDK) is to catalyze the reversible exchange of the γ-phosphate between nucleoside triphosphate (NTP) and nucleoside diphosphate (NDP). This kinase also has functions that extend beyond its canonically defined enzymatic role as a phosphotransferase. However, the role of NDK in filamentous fungi, especially in Aspergillus flavus (A. flavus), is not yet known. Here we report that A. flavus has two NDK-encoding gene copies as assessed by qPCR. Using gene-knockout and complementation experiments, we found that AfNDK regulates spore and sclerotia development and is involved in plant virulence as assessed in corn and peanut seed-based assays. An antifungal test with the inhibitor azidothymidine suppressed AfNDK activity in vitro and prevented spore production and sclerotia formation in A. flavus, confirming AfNDK's regulatory functions. Crystallographic analysis of AfNDK, coupled with site-directed mutagenesis experiments, revealed three residues (Arg-104, His-117, and Asp-120) as key sites that contribute to spore and sclerotia development. These results not only enrich our knowledge of the regulatory role of this important protein in A. flavus, but also provide insights into the prevention of A. flavus infection in plants and seeds, as well as into the structural features relevant for future antifungal drug development.

Inhibitory Effect of Volatiles Emitted From Alcaligenes faecalis N1-4 on Aspergillus flavus and Aflatoxins in Storage.

Controlling aflatoxigenic Aspergillus flavus and aflatoxins (AFs) in grains and food during storage is a great challenge to humans worldwide. Alcaligenes faecalis N1-4 isolated from tea rhizosphere soil can produce abundant antifungal volatiles, and greatly inhibited the growth of A. flavus in un-contacted face-to-face dual culture testing. Gas chromatography tandem mass spectrometry revealed that dimethyl disulfide (DMDS) and methyl isovalerate (MI) were two abundant compounds in the volatile profiles of N1-4. DMDS was found to have the highest relative abundance (69.90%, to the total peak area) in N1-4, which prevented the conidia germination and mycelial growth of A. flavus at 50 and 100 μL/L, respectively. The effective concentration for MI against A. flavus is 200 μL/L. Additionally, Real-time quantitative PCR analysis proved that the expression of 12 important genes in aflatoxin biosynthesis pathway was reduced by these volatiles, and eight genes were down regulated by 4.39 to 32.25-folds compared to control treatment with significant differences. And the A. flavus infection and AFs contamination in groundnut, maize, rice and soybean of high water activity were completely inhibited by volatiles from N1-4 in storage. Scanning electron microscope further proved that A. flavus conidia inoculated on peanuts surface were severely damaged by volatiles from N1-4. Furthermore, strain N1-4 showed broad and antifungal activity to other six important plant pathogens including Fusarium graminearum, F. equiseti, Alternaria alternata, Botrytis cinerea, Aspergillus niger, and Colletotrichum graminicola. Thus, A. faecalis N1-4 and volatile DMDS and MI may have potential to be used as biocontrol agents to control A. flavus and AFs during storage.

Pseudomonas fluorescens Pf7: A Potential Biocontrol Agent against Aspergillus flavus Induced Aflatoxin Contamination in Groundnut

Aflatoxin contamination is a qualitative problem in groundnut (Arachis hypogaea L.) occurring at both pre-and post-harvest stages. These aflatoxins are secondary metabolites produced by Aspergillus flavus and A. parasiticus and have carcinogenic, hepatotoxic, teratogenic and immuno-suppressive effects. Use of plant growth-promoting rhizobacteria (PGPR) is a viable and sustainable option in managing aflatoxin problem in groundnut. Our present study is aimed at identifying a plant growth-promoting rhizobacteria (PGPR) strain with superior antagonistic abilities on A. flavus infection, aflatoxin contamination and to determine its mode of action. Ten native P. fluorescens isolates were isolated from groundnut rhizosphere and screened against A. flavus by dual culture and in vitro seed colonization (IVSC) assays. In dual culture and IVSC studies, Pf7 exhibited higher degree of antagonism on A. flavus (54% inhibition), inhibited its colonization and reduced aflatoxin contamination (27.8 µg kg-1) in kernels.

Effects of postharvest handling practices on quality of groundnuts and aflatoxin contamination

The increased cases of aflatoxin contamination are exacerbated by poor post-harvest management practices, coupled with adverse climatic conditions at harvest and post-harvest stages. This study therefore was carried out to improve safety and quality of groundnuts from aflatoxin contamination, through use of proper postharvest handling practices. Specifically the study determined the effects of harvesting dates and drying methods on aflatoxin contamination. Field experiments were carried out both at Chitedze and Chitala Agricultural Research Stations in Malawi during 2017/2018 growing season. A randomized complete block design in a split plot arrangement with three harvesting dates as the main plot and four drying methods as the sub-plots replicated three times was used. Groundnut was assessed for kernel infection by Aspergillus flavus, and level of aflatoxin contamination. Significantly low levels of about 0.5μg/ Kg of A. flavus infection and aflatoxin contamination were observed at 90 days after sowing (DAS). Higher aflatoxin contamination of up to 5μg/ Kg was observed at 80 DAS, and 10 days late after physiological maturity (100 DAS). This study also identified Mandela cock, aframe drying rack as effective drying method that can reduce aflatoxin contamination in groundnuts by 75 %. Moreover, Mandela cock drying method was shown as the most effective compared to A-frame and drying rack drying method. Current study therefore recommends for adoption of timely harvesting at physiological maturity, and drying using either Mandela cock or A-frame and drying rack. Further studies need to be carried on biological control of aflatoxin contamination.

Contribution of Maize Polyamine and Amino Acid Metabolism Toward Resistance Against Aspergillus flavus Infection and Aflatoxin Production.

Polyamines (PAs) are ubiquitous polycations found in plants and other organisms that are essential for growth, development, and resistance against abiotic and biotic stresses. The role of PAs in plant disease resistance depends on the relative abundance of higher PAs [spermidine (Spd), spermine (Spm)] vs. the diamine putrescine (Put) and PA catabolism. With respect to the pathogen, PAs are required to achieve successful pathogenesis of the host. Maize is an important food and feed crop, which is highly susceptible to Aspergillus flavus infection. Upon infection, the fungus produces carcinogenic aflatoxins and numerous other toxic secondary metabolites that adversely affect human health and crop value worldwide. To evaluate the role of PAs in aflatoxin resistance in maize, in vitro kernel infection assays were performed using maize lines that are susceptible (SC212) or resistant (TZAR102, MI82) to aflatoxin production. Results indicated significant induction of both PA biosynthetic and catabolic genes upon A. flavus infection. As compared to the susceptible line, the resistant maize lines showed higher basal expression of PA metabolism genes in mock-inoculated kernels that increased upon fungal infection. In general, increased biosynthesis and conversion of Put to Spd and Spm along with their increased catabolism was evident in the resistant lines vs. the susceptible line SC212. There were higher concentrations of amino acids such as glutamate (Glu), glutamine (Gln) and γ-aminobutyric acid (GABA) in SC212. The resistant lines were significantly lower in fungal load and aflatoxin production as compared to the susceptible line. The data presented here demonstrate an important role of PA metabolism in the resistance of maize to A. flavus colonization and aflatoxin contamination. These results provide future direction for the manipulation of PA metabolism in susceptible maize genotypes to improve aflatoxin resistance and overall stress tolerance.

Method for screening resistance of peanut shell to Aspergillus flavus infection and identification of resistant genotypes

Method for screening resistance of peanut shell to Aspergillus flavus infection and identification of resistant genotypes

The Development of a qPCR Assay to Measure Aspergillus flavus Biomass in Maize and the Use of a Biocontrol Strategy to Limit Aflatoxin Production.

Aspergillus flavus colonisation of maize can produce mycotoxins that are detrimental to both human and animal health. Screening of maize lines, resistant to A. flavus infection, together with a biocontrol strategy, could help minimize subsequent aflatoxin contamination. We developed a qPCR assay to measure A. flavus biomass and showed that two African maize lines, GAF4 and KDV1, had different fungal loads for the aflatoxigenic isolate (KSM014), fourteen days after infection. The qPCR assay revealed no significant variation in A. flavus biomass between diseased and non-diseased maize tissues for GAF4, while KDV1 had a significantly higher A. flavus biomass (p < 0.05) in infected shoots and roots compared to the control. The biocontrol strategy using an atoxigenic isolate (KSM012) against the toxigenic isolate (KSM014), showed aflatoxin production inhibition at the co-infection ratio, 50:50 for both maize lines (KDV1 > 99.7% and GAF ≥ 69.4%), as confirmed by bioanalytical techniques. As far as we are aware, this is the first report in Kenya where the biomass of A. flavus from maize tissue was detected and quantified using a qPCR assay. Our results suggest that maize lines, which have adequate resistance to A. flavus, together with the appropriate biocontrol strategy, could limit outbreaks of aflatoxicoses.

Transcriptome and proteome analyses of resistant preharvest peanut seed coat in response to Aspergillus flavus infection

The infection of peanut (Arachis hypogaea L.) seed coat by the pathogenic fungus Aspergillus flavus has highly negative economic and health impacts. However, the molecular mechanism underlying such defense response remains poorly understood. This study aims to address this issue by profiling the transcriptomic and proteomic changes that occur during the infection of the resistant peanut cultivar J11 by A. flavus. Transcriptomic study led to the detection of 13,539 genes, among which 663 exhibited differential expression. Further functional analysis found the differentially expressed genes to encode a wide range of pathogenesis- and/or defense-related proteins such as transcription factors, pathogenesis-related proteins, and chitinases. Changes in the expression patterns of these genes might contribute to peanut resistance to A. flavus. On the other hand, the proteomic profiling showed that 314 of the 1382 detected protein candidates were aberrantly expressed as a result of A. flavus invasion. However, the correlation between the transcriptomic and proteomic data was poor. We further demonstrated by in vitro fungistasis tests that hevamine-A, which was enriched at both transcript and protein levels, could directly inhibit the growth of A. flavus. The results demonstrate the power of complementary transcriptomic and proteomic analyses in the study of pathogen defense and resistance in plants and the chitinase could play an important role in the defense response of peanut to A. flavus. The current study also constitutes the first step toward building an integrated omics data platform for the development of Aspergillus-resistant peanut cultivars. How to cite: Zhao X, Li C, Yan C, et al. Transcriptome and proteome analyses of resistant preharvest peanut seed-coat in response to Aspergillus flavus infection. Electron J Biotechnol 2019;39. https://doi.org/10.1016/j.ejbt.2019.03.003.

Cultural and Genetic Approaches to Manage Aflatoxin Contamination: Recent Insights Provide Opportunities for Improved Control.

Aspergillus flavus is a morphologically complex species that can produce the group of polyketide derived carcinogenic and mutagenic secondary metabolites, aflatoxins, as well as other secondary metabolites such as cyclopiazonic acid and aflatrem. Aflatoxin causes aflatoxicosis when aflatoxins are ingested through contaminated food and feed. In addition, aflatoxin contamination is a major problem, from both an economic and health aspect, in developing countries, especially Asia and Africa, where cereals and peanuts are important food crops. Earlier measures for control of A. flavus infection and consequent aflatoxin contamination centered on creating unfavorable environments for the pathogen and destroying contaminated products. While development of atoxigenic (nonaflatoxin producing) strains of A. flavus as viable commercial biocontrol agents has marked a unique advance for control of aflatoxin contamination, particularly in Africa, new insights into the biology and sexuality of A. flavus are now providing opportunities to design improved atoxigenic strains for sustainable biological control of aflatoxin. Further, progress in the use of molecular technologies such as incorporation of antifungal genes in the host and host-induced gene silencing, is providing knowledge that could be harnessed to develop germplasm that is resistant to infection by A. flavus and aflatoxin contamination. This review summarizes the substantial progress that has been made to understand the biology of A. flavus and mitigate aflatoxin contamination with emphasis on maize. Concepts developed to date can provide a basis for future research efforts on the sustainable management of aflatoxin contamination.

Occurrence of aflatoxin B1 inTriticum species inoculated withAspergillus flavus

Effects of climate change, global trade and technological changes in processing industries cause higher occurrence ofAspergillus flavusand aflatoxin B1(AFB1) in cereal crops. FourTriticumspecies: common wheat (Triticum aestivumL.), spelt (T. aestivumssp.speltaL.), Khorasan wheat (Triticum turgidumssp.turanicumJakubz.) and hybrid wheat (T. aestivumL.– F1) were examined for their response toA. flavusinfection and production of AFB1. The grains were obtained from control and artificially field inoculated wheat withA. flavusisolates (No. 1 and No. 2) in the 2016 vegetation season in the region of Vojvodina (Northern province of Serbia). Spelt wheat showed the strongest response to the infection in comparison to other analysed wheat species due to specific physico-chemical characteristics of the hull. The weakest response toA. flavusinfections was noted in Khorasan wheat. The highest AFB1level (256 μg/kg) was observed in the dehulled spelt grains, in comparison to other species where the AFB1in dehulled grains was not detected. The levels of AFB1in spelt were about three times higher in hulls (648 and 97.3 μg/kg, respectively) in comparison to grains (256 and 30.7 μg/kg, respectively) in two inoculation treatments (A. flavusNo. 1 and No. 2, respectively). In order to investigate the impact of wheat hulls on development ofA. flavus, including the biosynthesis of toxic fungal metabolites, physico-chemical and structural properties of differentTriticumspp. hulls were characterised. The highest value of the water absorption index and total dietary fibre were observed in spelt hulls in comparison to other wheat species. Additionally, the height value distribution of the fossilized stomatal apparatus of hulls indicates the diversity of spelt wheat compared to other wheat species.

Identification of candidate resistance genes of cotton against Aspergillus flavus infection using a comparative transcriptomics approach.

A comparative transcriptome analysis was performed using the genes significantly differentially expressed in cotton, corn and peanut in response to aflatoxin producing fungus Aspergillus flavus with an objective of identifying candidate resistance genes in cotton. Two-way analyses identified 732 unique genes to be differentially regulated by the fungus with only 26 genes common across all three crops that were considered candidate A. flavus resistance genes with an assumption that these genes have specific roles in conferring the resistance trait. Genes of membrane cellular component involved in DNA binding with involvement in defense responses were highly represented among the differentially expressed unique genes. Most (six) of these genes coded for 2-oxoglutarate (2OG) and Fe(II)-dependent oxygenase superfamily proteins. Genes encoding helix loop helix protein, alcohol dehydrogenase and UDP glycosylation transferase which were upregulated in response to both atoxigenic and toxigenic strains of A. flavus, could be potential resistance candidate genes for downstream functional manipulation to confer resistance.

Optimal pcr primers for rapid and accurate detection of Aspergillus flavus isolates

Aspergillus flavus is among the most devastating opportunistic pathogens of several food crops including rice, due to its high production of carcinogenic aflatoxins. The presence of these organisms in economically important rice strip farming is a serious food safety concern. Several polymerase chain reaction (PCR) primers have been designed to detect this species; however, a comparative assessment of their accuracy has not been conducted. This study aims to identify the optimal diagnostic PCR primers for the identification of A. flavus, among widely available primers. We isolated 122 A. flavus native isolates from randomly collected rice strips (N = 300). We identified 109 isolates to the genus level using universal fungal PCR primer pairs. Nine pairs of primers were examined for their PCR diagnostic specificity on the 109 isolates. FLA PCR was found to be the optimal PCR primer pair for specific identification of the native isolates, over aflP(1), aflM, aflA, aflD, aflP(3), aflP(2), and aflR. The PEP primer pair was found to be the most unsuitable for A. flavus identification. In conclusion, the present study indicates the powerful specificity of the FLA PCR primer over other commonly available diagnostic primers for accurate, rapid, and large-scale identification of A. flavus native isolates. This study provides the first simple, practical comparative guide to PCR-based screening of A. flavus infection in rice strips.

Survey of Candidate Genes for Maize Resistance to Infection by Aspergillus flavus and/or Aflatoxin Contamination.

Many projects have identified candidate genes for resistance to aflatoxin accumulation or Aspergillus flavus infection and growth in maize using genetic mapping, genomics, transcriptomics and/or proteomics studies. However, only a small percentage of these candidates have been validated in field conditions, and their relative contribution to resistance, if any, is unknown. This study presents a consolidated list of candidate genes identified in past studies or in-house studies, with descriptive data including genetic location, gene annotation, known protein identifiers, and associated pathway information, if known. A candidate gene pipeline to test the phenotypic effect of any maize DNA sequence on aflatoxin accumulation resistance was used in this study to determine any measurable effect on polymorphisms within or linked to the candidate gene sequences, and the results are published here.

Granulomatous Invasive Aspergillus flavus Infection Involving the Nasal Sinuses and Brain.

Invasive fungal infections are commonly associated with some form of immunosuppression. On the nasal epithelial surface, Aspergillus flavus, under favorable conditions, can aggressively breach multiple cell lines invading the local tissues. We present the case of a 35-year-old woman with granulomatous invasive Aspergillus flavus infection involving the nasal sinuses and the brain. Antifungal agents administered in the previous episodes contained the infection; however, the infected site evolved over time surrounded with calcified tissues in the left maxillary sinus. The current infection involved the other side of the maxillary sinus and extended to the orbital cavity eroding the parts of the skull and retro-orbital structures and was treated with a long course of isavuconazole therapy.

Serum Cytokine Profile in Patients with Chronic Rhinosinusitis with Nasal Polyposis Infected by Aspergillus flavus.

BackgroundFungi, especially Aspergillus flavus, can cause chronic rhinosinusitis with nasal polyposis and modulate host innate immune components. The objective of this study was to examine the serum levels of T helper (Th) cell subset Th1, Th2, and Th17 cytokines and total IgE in patients having chronic rhinosinusitis with nasal polyposis and Aspergillus flavus infection.MethodsA case-control study including 40 patients with chronic rhinosinusitis with nasal polyposis and 20 healthy controls was conducted. Aspergillus flavus infection was confirmed by standard potassium hydroxide (KOH) testing, culture, and PCR. Serum samples of all patients and controls were analyzed for various cytokines (interleukins [IL]-1β, IL-2, IL-4, IL-6, IL-17, IL-21, IL-27, TGF-β) and total IgE by ELISA. Data from patients with Aspergillus flavus infection and healthy volunteers were compared using the independent t-test and non-parametric Mann-Whitney U test.ResultsAspergillus flavus infection was found in 31 (77.5%) patients with chronic rhinosinusitis with nasal polyposis. IL-1β, IL-17, IL-21, and TGF-β serum levels were significantly higher in these patients than in controls; however, IL-2, IL-4, IL-6, and IL-27 levels were lower. Compared with nine (22.5%) patients without Aspergillus flavus infection, IL-17 level was higher while IL-2 level was lower in patients with Aspergillus flavus infection. Total IgE was significantly higher in patients with Aspergillus flavus infection than in controls.ConclusionsHigh levels of IL-17 and its regulatory cytokines in patients with chronic rhinosinusitis with nasal polyposis infected by Aspergillus flavus raise a concern about effective disease management and therapeutic recovery. Surgical removal of the nasal polyp being the chief management option, the choice of post-operative drugs may differ in eosinophilic vs. non-eosinophilic nasal polyposis. The prognosis is likely poor, warranting extended care.

English

Aflatoxin contamination is a qualitative problem in groundnut (Arachis hypogaea L.) occurring at both pre-and post-harvest stages. These aflatoxins are secondary metabolites produced by Aspergillus flavus and A. parasiticus and have carcinogenic, hepatotoxic, teratogenic and immuno-suppressive effects. To evaluate the prevalence of A. flavus infection and aflatoxin contamination in groundnut oil mills/traders’ of Telangana and Andhra Pradesh (AP) pod samples were collected from eight selected oil mills/traders’ in Mahaboobnagar, Rangareddy, Nizamabad, Karimnagar (Telangana); and Anantapur (AP) districts. A total of 24 pod samples were collected (Three samples from the each selected oil mill). Aflatoxin contamination in kernels was estimated by indirect competitive ELISA. In Telangana, kernel infection ranged from 42 (Mahaboobnagar) to 90.7% (Nizamabad). In AP, Tadimarri mandal recorded kernel infection up to 29.3% whereas Tadipatri recorded up to 59.3%. Aflatoxins in kernels from these mills in Telangana were highest in Rangareddy (1205.2 µg kg-1 ) followed by Karimnagar (365.5 µg kg-1 ). Oil mills of Nizamabad and Mahaboobnagar have recorded aflatoxins to a tune of 4.9 and 11.5 µg kg-1 in Telangana. In AP, aflatoxins in pod samples were 2.8 µg kg-1 (Tadipatri) and 6148.4 µg kg-1 (Tadimarri).

The Pathogenesis-Related Maize Seed (PRms) Gene Plays a Role in Resistance to Aspergillus flavus Infection and Aflatoxin Contamination

Aspergillus flavus is an opportunistic plant pathogen that colonizes and produces the toxic and carcinogenic secondary metabolites, aflatoxins, in oil-rich crops such as maize (Zea mays ssp. mays L.). Pathogenesis-related (PR) proteins serve as an important defense mechanism against invading pathogens by conferring systemic acquired resistance in plants. Among these, production of the PR maize seed protein, ZmPRms (AC205274.3_FG001), has been speculated to be involved in resistance to infection by A. flavus and other pathogens. To better understand the relative contribution of ZmPRms to A. flavus resistance and aflatoxin production, a seed-specific RNA interference (RNAi)-based gene silencing approach was used to develop transgenic maize lines expressing hairpin RNAs to target ZmPRms. Downregulation of ZmPRms in transgenic kernels resulted in a ∼250–350% increase in A. flavus infection accompanied by a ∼4.5–7.5-fold higher accumulation of aflatoxins than control plants. Gene co-expression network analysis of RNA-seq data during the A. flavus-maize interaction identified ZmPRms as a network hub possibly responsible for regulating several downstream candidate genes associated with disease resistance and other biochemical functions. Expression analysis of these candidate genes in the ZmPRms–RNAi lines demonstrated downregulation (vs. control) of a majority of these ZmPRms-regulated genes during A. flavus infection. These results are consistent with a key role of ZmPRms in resistance to A. flavus infection and aflatoxin accumulation in maize kernels.