Flavus Infection Research Articles

Ozonation of Popcorn Kernels: Saturation Kinetics at Different Specific Flow Rates, Control of Aspergillus flavus Infection, and Grain Quality Analysis.

Ozone gas (O3) is a promising alternative for fungal inactivation in agricultural commodities. This study aimed to (i) investigate the influence of airflow on the saturation of popcorn kernels with ozone gas, (ii) evaluate its effectiveness in controlling Aspergillus flavus, and (iii) analyze the quality of ozonated grains. Samples of 3.0 kg of kernels were exposed to oxygen (control) or ozone at specific flow rates of 0.15 or 1.00 m3 min-1 t-1, with an input ozone concentration of 16.0 mg L-1 for 0, 6, 12, 24, 36, or 48 h. Quality parameters assessed included expansion volume, water content, electrical conductivity, and color. At 0.15 m3 min-1 t-1, ozone consumption and saturation time were lower, with an 80% reduction in A. flavus infection after 6 h. This flow rate did not affect grain expansion or water content. Conversely, at 1.0 m3 min-1 t-1, reductions in water content and expansion were observed with extended exposure. Electrical conductivity increased in both treatments, more significantly at the lower flow rate. In conclusion, ozonation at 0.15 m3 min-1 t-1 effectively inactivated A. flavus without compromising grain quality.

Identification and Characterization of Peanut Seed Coat Secondary Metabolites Inhibiting Aspergillus flavus Growth and Reducing Aflatoxin Contamination.

The peanut seed coat acts as a physical and biochemical barrier against Aspergillus flavus infection; however, the nature of the inhibitory chemicals in the peanut seed coat in general is not known. This study identified and characterized peanut seed coat metabolites that inhibit A. flavus growth and aflatoxin contamination. Selected peanut accessions grown under well-watered and water-deficit conditions were assayed for A. flavus resistance, and seed coats were metabolically profiled using liquid chromatography mass spectrometry. Kyoto Encyclopedia of Genes and Genome phenylpropanoid pathway reference analysis resulted in the identification of several seed coat metabolic compounds, and ten selected metabolites were tested for inhibition of A. flavus growth and aflatoxin contamination. Radial growth bioassay demonstrated that 2,5-dihydroxybenzaldehyde inhibited A. flavus growth (98.7%) and reduced the aflatoxin contamination estimate from 994 to 1 μg/kg. Scanning electron micrographs showed distorted hyphae and conidiophores in cultures of 2,5-dihydroxybenzaldehyde-treated A. flavus, indicating its potential use for field application as well as seed coat metabolic engineering.

A Klebsiella rhizobacterium deregulates the metabolism of phytopathogenic Aspergillus flavus during in-vitro assays and confers protective functions

In previous investigations, we have identified a rhizobacterium (Klebsiella sp. MBE02) that confers host protection against several phytopathogenic fungi. For instance, this rhizobacterium prevents Aspergillus flavus infection and promotes peanut growth and fitness in controlled and field-conditions. The mechanistic basis of the protective function offered by this rhizobacterium is not completely understood. MBE02 directly restricts the growth of the pathogenic fungi, which led us to hypothesize that it may strongly dysregulate the metabolism of A. flavus, and inhibit critical metabolic processes of the fungus, which severely restricts pathogen growth. We have tested this hypothesis by using untargeted metabolite profiling. Sixty-nine A. flavus metabolites accumulated differentially due to the presence of the MBE02. MBE02 could inhibit several important metabolic pathways, which include the biosynthesis of critical primary metabolites such as amino acids and fatty acids. It also impacts energy metabolism of the fungus, and that the accumulation of several structural components, including of the cell wall, were strongly inhibited. MBE02 abrogated the accumulation of disease-causing metabolites in A. flavus, whereas the accumulation of metabolites that inhibit fungal growth were enhanced. On the other hand, A. flavus did not strikingly impact the accumulation of metabolites of the MBE02. Our investigation supports the hypothesis that Klebsiella sp. MBE02 mediates protective function by directly impairing the pathogen’s metabolism.

Disseminated Aspergillus Flavus Infection in High-Risk Acute Promyelocytic Leukemia: A Case for Early Recognition and Pharmacokinetic Guided Treatment Approach

Disseminated Aspergillus Flavus Infection in High-Risk Acute Promyelocytic Leukemia: A Case for Early Recognition and Pharmacokinetic Guided Treatment Approach

Effects of Different Shelling Methods on Data Variability during Field Screening for Reduced Aflatoxin Contamination in Maize.

Non-genetic variation limits the identification of novel maize germplasm with genetic markers for reduced Aspergillus flavus infection and aflatoxin contamination. Aflatoxin measurements can vary substantially within fields containing the same germplasm following inoculation with A. flavus. While some variation is expected due to microenvironmental differences, components of field screening methodologies may also contribute to variability in collected data. Therefore, the objective of this study is to test the effects of three different shelling methods (whole ear (WE), ear end removal (EER), and inoculation site-surrounding (ISS)) to obtain bulk samples from maize on aflatoxin measurements. Five ears per row of three inbred lines and two hybrids were inoculated with A. flavus, then shelled using the three different methods, and aflatoxin was quantified. Overall, EER and ISS resulted in reduced coefficients of variance (CVs) in comparison to WE for both inbred and hybrid maize lines, with two exceptions. Susceptible B73 showed increased CVs with both EER and ISS compared to WE, and resistant Mp719's EER CVs marginally increased compared to WE. While WE is the standard practice for most breeding programs due to its technical simplicity, EER and ISS may allow for finely phenotyping parental lines for further breeding applications.

Biological control of Aspergillus flavus infection and growth promotion of peanut seedlings by Lactiplantibacillus plantarum and Levilactobacillus brevis

BackgroundAspergillus spp. infection might induce negative effects on peanut seeds, including decreased germination rates and suppressed seedling vigor. Furthermore, A. flavus can secret aflatoxin, regarding food safety and human health. The prolonged use of fungicides for treating mold infections has raised concerns regarding the emergence of fungicide-resistant strains, environmental pollution, and adverse effects on human health. The usage of lactic acid bacteria, including Lactiplantibacillus plantarum and Levilactobacillus brevis for the management of plant diseases, has garnered increasing attention in recent years as a viable alternative to chemical-based therapies. This study aimed to investigate the efficacy of LABs in pre-treating peanut seeds as a biological solution against A. flavus infection before cultivation.ResultsLactiplantibacillus plantarum and Levilactobacillus brevis have demonstrated the ability to suppress A. flavus in vitro. In the in vivo investigation, pre-treatment of peanut seeds with cell-free supernatant derived from L. plantarum (LP-CFS) and L. brevis (LB-CFS) significantly reduced A. flavus infection levels. The conidial count decreased from 8.63 log conidia/g in the untreated group to 5.35 log conidia/g with LP-CFS treatment and 4.59 log conidia/g with LB-CFS treatment. Additionally, A. flavus infection reduced the germination rate of peanut seeds to only 20.4% compared to 63.6% in the control group. In comparison, pre-treatment with LP-CFS and LB-CFS increased the germination rate to 75.6% and 76.8%, respectively, and further improved the vigor index in A. flavus-infected peanut seeds.ConclusionThe present findings indicated that bioactive compounds derived from L. plantarum and L. brevis emerge as promising candidates for treating peanut seeds, effectively protecting them against A. flavus infection. Moreover, these compounds facilitate the growth of seedlings, which could be a potential alternative to chemical fungicides, and contribute to sustainable agricultural development.

Effects of Aspergillus flavus infection on multi-scale structures and physicochemical properties of maize starch during storage

This study systematically analyzed the effect of Aspergillus flavus infection on the maize starch multi-scale structure, physicochemical properties, processing characteristics, and synthesis regulation. A. flavus infection led to a decrease in the content of starch, an increase in the content of reactive oxygen species (ROS) and malondialdehyde (MDA), a significant decrease in the activities of peroxidase (POD) and superoxide dismutase (SOD). In addition, A. flavus infection had a significant destructive effect on the double helix structure, relative crystallinity and lamellar structure of starch, resulting in the reduction of starch viscosity, affecting the viscoelastic properties of starch, and complicating the gel formation process. However, the eugenol treatment group significantly inhibited the growth of A. flavus during maize storage, protecting the multi-scale structure and processing characteristics of maize starch from being damaged. Transcriptome analysis showed that genes involved in carbohydrate synthesis in maize were significantly downregulated and genes involved in energy synthesis were significantly upregulated, indicating that maize converted its energy storage into energy synthesis to fight the invasion of A. flavus. These results of this study enriched the mechanism of quality deterioration during maize storage, and provide theoretical and technical support for the prevention of A. flavus infection during maize storage.

Inhibitory mechanism and application of cinnamon essential oil against Aspergillus flavus

Aspergillus flavus produces highly toxic and carcinogenic aflatoxins that cause severe economic losses and pose a serious threat to public health. Cinnamon essential oils (CEO) have recently attracted attention as promising alternative antifungal agents. In this study, the inhibition mechanism of CEO on A. flavus was investigated, and its application in the prevention of A. flavus in coix seeds was explored for the first time. The results showed that mycelial growth, spore germination, and aflatoxin synthesis of A. flavus were completely inhibited after treatment with 0.5 μL/mL of CEO. Morphological, physiological, and biochemical changes after CEO treatment were also analyzed to elucidate the inhibitory mechanism. Transcriptomic analysis showed that some genes involved in conidiophore development (flbA and abaA), ergosterol synthesis (CYP51, Erg1, Erg3, Erg7, Erg9, Erg24, and Erg25), aflatoxin biosynthesis (aflR, aflO, aflT, aflJ, aflW, and aflY), and oxidative stress (Pbs2, Ste20, CAT, atfB, mtfA, PacC, ppoC, and gprM) were significantly regulated. Moreover, A. flavus infection in coix seeds was effectively inhibited by 20.0 μL/g of CEO. This study shed important light on the processes underlying the antifungal mechanism of CEO and affirmed the possibility of using CEO as a green anti-aflatoxigenic agent in the preservation of coix seed.

MicroRNA (miRNA) profiling of maize genotypes with differential response to Aspergillus flavus implies zma-miR156–squamosa promoter binding protein (SBP) and zma-miR398/zma-miR394–F -box combinations involved in resistance mechanisms

Maize (Zea mays), a major food crop worldwide, is susceptible to infection by the saprophytic fungus Aspergillus flavus that can produce the carcinogenic metabolite aflatoxin (AF) especially under climate change induced abiotic stressors that favor mold growth. Several studies have used “-omics” approaches to identify genetic elements with potential roles in AF resistance, but there is a lack of research identifying the involvement of small RNAs such as microRNAs (miRNAs) in maize-A. flavus interaction. In this study, we compared the miRNA profiles of three maize lines (resistant TZAR102, moderately resistant MI82, and susceptible Va35) at 8 h, 3 d, and 7 d after A. flavus infection to investigate possible regulatory antifungal role of miRNAs. A total of 316 miRNAs (275 known and 41 putative novel) belonging to 115 miRNA families were identified in response to the fungal infection across all three maize lines. Eighty-two unique miRNAs were significantly differentially expressed with 39 miRNAs exhibiting temporal differential regulation irrespective of the maize genotype, which targeted 544 genes (mRNAs) involved in diverse molecular functions. The two most notable biological processes involved in plant immunity, namely cellular responses to oxidative stress (GO:00345990) and reactive oxygen species (GO:0034614) were significantly enriched in the resistant line TZAR102. Coexpression network analysis identified 34 hubs of miRNA-mRNA pairs where nine hubs had a node in the module connected to their target gene with potentially important roles in resistance/susceptible response of maize to A. flavus. The miRNA hubs in resistance modules (TZAR102 and MI82) were mostly connected to transcription factors and protein kinases. Specifically, the module of miRNA zma-miR156b-nb – squamosa promoter binding protein (SBP), zma-miR398a-3p – SKIP5, and zma-miR394a-5p – F-box protein 6 combinations in the resistance-associated modules were considered important candidates for future functional studies.

Dietary multi-strains Bacillus spp. enhanced growth performance, blood metabolites, digestive tissues histology, gene expression of Oreochromis niloticus, and resistance to Aspergillus flavus infection

The present study tested the symbiotic effects of dietary multi-strain Bacillus probiotics (MSB) (Bacillus licheniformis, B. pumilus, and B. subtilis) in Nile tilapia (Oreochromis niloticus) exposed to Aspergillus flavus infection. Furthermore, this study investigated water quality, growth performance, blood metabolites, histological morphology, immune regulatory genes, and resistance to A. flavus infection. For 70 days, fish (n = 240) were divided into four groups in triplicate: T0 (control group; MSB0), T1 (1 g/kg, MSB1), T2 (2 g/kg, MSB2), and T3 (3 g/kg, MSB3). The immune response was then assessed by challenging all fish groups with the A. flavus pathogen. The results showed that the rearing water quality, fish growth, and blood parameters, as well as total proteins, albumin, globulins, and amylase activity were significantly (P < 0.05) increased in all MSB-treated groups with the best results in MSB2 and MSB3 groups. Meanwhile, the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), cholesterol, and glucose levels were significantly (P < 0.05) modulated, particularly at higher concentrations of the probiotic mixture (MSB3 group). Fish fed with various levels of MSB showed a maintained histological structure of the hepatopancreas, intestine, and spleen tissues. The mRNA expression of growth hormone (GH), insulin-like growth factor-1 (IGF-1), insulin-like growth factor receptor-1 (IGF-1R), and interleukin-8 (IL-8) were increased in a dose-dependent manner due to MSB dietary inclusion (P < 0.05). Conversely, the mRNA expression of interleukin-1β (IL-1β) gene was significantly decreased in MSB groups compared to untreated group (P < 0.05). Surprisingly, supplemented groups in Bacillus spp. probiotics exhibited significant modulations in all computed parameters. MSB supplementation improved the pathogenic tolerance of tilapia after change with A. flavus. The integration of growth performance, biochemical, and transcriptomic results confirms that the dietary intervention of multi-strain Bacillus spp. is symbiotic and enhances the benefits for the maintenance of O. niloticus’ health, growth, and digestion. This is achieved by supporting growth genes, reducing inflammatory genes, and enhancing immune-antioxidant resistance to combat A. flavus infection.

In-water Bacillus species probiotic improved water quality, growth, hemato-biochemical profile, immune regulatory genes and resistance of Nile tilapia to Aspergillus flavus infection

In-water Bacillus species probiotic improved water quality, growth, hemato-biochemical profile, immune regulatory genes and resistance of Nile tilapia to Aspergillus flavus infection

Genome-Wide Characterization of the Phenylalanine Ammonia-Lyase Gene Family and Their Potential Roles in Response to Aspergillus flavus L. Infection in Cultivated Peanut (Arachis hypogaea L.).

Phenylalanine ammonia-lyase (PAL) is an essential enzyme in the phenylpropanoid pathway, in which numerous aromatic intermediate metabolites play significant roles in plant growth, adaptation, and disease resistance. Cultivated peanuts are highly susceptible to Aspergillus flavus L. infection. Although PAL genes have been characterized in various major crops, no systematic studies have been conducted in cultivated peanuts, especially in response to A. flavus infection. In the present study, a systematic genome-wide analysis was conducted to identify PAL genes in the Arachis hypogaea L. genome. Ten AhPAL genes were distributed unevenly on nine A. hypogaea chromosomes. Based on phylogenetic analysis, the AhPAL proteins were classified into three groups. Structural and conserved motif analysis of PAL genes in A. hypogaea revealed that all peanut PAL genes contained one intron and ten motifs in the conserved domains. Furthermore, synteny analysis indicated that the ten AhPAL genes could be categorized into five pairs and that each AhPAL gene had a homologous gene in the wild-type peanut. Cis-element analysis revealed that the promoter region of the AhPAL gene family was rich in stress- and hormone-related elements. Expression analysis indicated that genes from Group I (AhPAL1 and AhPAL2), which had large number of ABRE, WUN, and ARE elements in the promoter, played a strong role in response to A. flavus stress.

Efficiency of Persicaria salicifolia as a natural alternative antifungal against Aspergillus flavus infection in Oreochromis niloticus from Aswan Governorate, Egypt

Fungal diseases in fish cause economic losses all over the world, and knowledge about them is scarce and outdated in Aswan Governorate, Egypt, making interpretation, prevention, and treatment difficult. The necessity to find a fungicide that is natural, environmentally friendly, and does not emerge drug resistance is a must. Therefore, the current study aimed to isolate and diagnose fungal infection in farmed Oreochromis niloticus, causing mortalities, in Aswan Governorate. During 2021, 200 fresh O. niloticus samples were collected from the Sahary Fish Hatchery and Aswan General Authority for Fish Resources Development fish farm. Some fish showed hemorrhagic lesions all over the body, detachment of scales, and fin erosion. Collected tissue samples were cultured on potato dextrose agar and Sabouraud dextrose agar for phenotypic characterization. Macroscopic and microscopic analyses were used to identify the isolated fungi. A total of 18 fungal species and two varieties appertaining to ten fungal genera were recovered from 48 samples out of 200 examined O. niloticus (24%), with Aspergillus flavus being the most prevalent at a rate of 25.6%. The isolated A. flavus was proven to be pathogenic to farmed O. niloticus, as by experimental infection. The natural herb Persicaria salicifolia had an LC50 value of 41.68 mg/l in exposed O. niloticus and was used to treat A. flavus-infected O. niloticus. It can be concluded that A. flavus poses a major hazard to O. niloticus aquaculture and can be treated with 40 mg/kg in feed or 20 mg/l in water of P. salicifolia for 6 days.

Evaluation of the Susceptibility of Lotus Seeds (Nelumbo nucifera Gaertn.) to Aspergillus flavus Infection and Aflatoxin Contamination.

The seeds of lotus (Nelumbo nucifera Gaertn.) have been used as significant medicinal and nutritional ingredients worldwide. The abundant proteins and polysaccharides in lotus seeds make them susceptible to contamination by aflatoxin (AF), a fungal toxic metabolite. This study was conducted to investigate the susceptibility of lotus seeds at different stages of ripening to AF contamination, as well as the mechanism of the contamination. Seven groups of lotus receptacles with seeds at different ripening stages (A-G, from immature to mature) were used for the experiment. Spores of Aspergillus flavus, an AF producer, were inoculated on the water-gap area of the seeds in each receptacle. Then, each receptacle was covered with a sterilized bag, and its stalk part was soaked in water containing a life-prolonging agent, after which it was kept at room temperature for 14 days. The AF content of each whole inoculated seed from the A-G groups and that of each seed part (pericarp, cotyledon, and embryo) from the D and E groups were determined using high-performance liquid chromatography. Microtome sections were prepared from the samples and observed under a light microscope and scanning electron microscope. The seeds from the A and D groups had higher AF contents than the seeds from the B, C, E, F, and G groups, indicating that the condition of the water-gap area and the development of the embryo and cotyledon parts of the seeds are associated with AF contamination.

Fatal pulmonary hemorrhage, pneumothorax and skin necrosis caused by IRIS to an Aspergillus flavus infection in a young patient with metamizole associated agranulocytosis

We report the case of a young female with steroid-dependent ulcerative colitis (UC) who developed a complex systemic infection with Aspergillus flavus. This occurred following a UC relapse while vacationing in the Middle East, leading to extended use of metamizole and subsequent agranulocytosis. On her return to Germany, she was hospitalized for neutropenic sepsis and later transferred to our hospital due to persistent cytopenia and suspected Hemophagocytic Lymphohistiocytosis (HLH). Despite initial stabilization with targeted treatment for pulmonary Aspergillus flavus infection, her condition rapidly deteriorated following the onset of an Immune Reconstitution Inflammatory Syndrome (IRIS), which manifested as skin necrosis and pneumothorax after the replenishment of neutrophil granulocytes. The patient eventually died from an unmanageable pulmonary hemorrhage. Microscopy of skin necroses showed a massive presence of Aspergillus flavus, but tissue culture remained negative, suggesting effective antifungal treatment yet delayed phagocytosis due to agranulocytosis. This case underscores the need to consider IRIS in immunosuppressed patients who worsen despite aggressive and appropriately targeted treatment, highlighting its potential beyond the commonly recognized context in HIV-positive patients.

Agronomic performance of maize hybrids under Aspergillus flavus inoculation in Cameroon

Maize (Zea mays L.) is a major staple crop in most of the sub-Sahara Africa (SSA) region, constrained by a multitude of plant diseases, with the ear and kernel rots being the most widespread and difficult to manage on maize. The objective of this study was to access the agronomic performance of F1 maize hybrids exposed to Aspergillus flavus, under different agro-ecological conditions, in Cameroon. A total of 120 genotypes of maize, including four commercial hybrids, were evaluated under A. flavus infection at two sites; namely Bangangte in the Western Highlands and Mbalmayo, in the Bimodal Humid Forest Zone of Cameroon. The study was conducted during 2020 - 2021 cropping seasons. Results revealed that at Bangangte site, six (89343X88094, 88099X88094, 90204XExp 124, 89246X87036, TZI-5-1171XExp 124 and 90219X1368) out of the top 20 high yielding hybrids, had significantly high (p&lt;0.001 tolerance (0% severity) to Aspergillus ear rot infection. At Mbalmayo site, eight (8923X88094, TZI-5-1171XExp124, 89343X88094, 90219X87036, 89243X87036, 87014X88094, TZSTR1150X87036 and 89248X88094) out of the top 20 high yielding hybrids also showed significant high (P&lt;0.001) tolerance (0% severity) to Aspergillus ear rot infection. The interaction between hybrids and location was significant (P&lt;0.05) for all measured traits, except ear height, grain texture, ear insect damage and husk cover (P&gt;0.05). The pooled broad sense heritability of hybrids in the two locations varied from 5% for grain texture to 92% for days to 50% physiological maturity. Grain yield was negatively correlated with Aspergillus ear rot disease incidence and severity. Hence, promising high yielding maize hybrids with appreciable tolerance to Aspergillus ear rot disease could be selected among the tested genotypes.

Pre-harvest host-resistance to Aspergillus infection and aflatoxin B1 contaminations in groundnut (Arachis hypogaea L.) genotypes

Groundnut (Arachis hypogaea L.) is an important oil crop in the tropical and sub-tropical countries. Pod and seed coat crack-inducing factors favour Aspergillus species infections and aflatoxin B1 (AFB1) contamination of groundnut. Aflatoxin B1 (AFB1), a toxic secondary metabolite of Aspergillus species, remains a global concern due to its human and animal health, and economic impacts. Thus, the study was conducted at Babile in 2018 with the objective to identify groundnut genotypes resistant to pre-harvest fungal infections, aflatoxin contaminations and associated effects in crop physiology. Seventeen advanced groundnut breeding lines including one commercial cultivar (Werer-961), were evaluated using randomized complete block design and completely randomized design under field and with four replications for laboratory experiments, respectively. Aflatoxin B1 analysis was carried out using Enzyme-Linked Immunosorbent Assay (ELISA) kits. Appropriate statistical procedures, including regression, were employed for data analyses. Highly significant (p<0.01) variation existed among the genotypes for A. flavus and A. niger infections, and the AFB1 contamination ranged from 13.98 (G14) to 1990.86 ppb (G12). The more A. flavus infection, the more reduction in harvest yield and seedling vigour. Fortunately, 53 % of the test materials were found to be resistant to AFB1 production, and frighteningly, none of the AFB1 contaminated genotypes were within the acceptable limit of the lenient standard (10 ppb). All in all, the groundnut genotype (G4) was identified as a good source of pre-harvest resistance to A. flavus infection, AFB1 contamination and seedling vigour so that its inclusion in breeding programs is worthwhile utmost, specifically, in the test environment as pathogen-crop-environment interaction is natural. Since the experiment was employed at one location and for only one year, it is suggested to repeat the experiment across multiple locations and over seasons for reliable recommendation.

Microbiota of maize kernels as influenced by Aspergillus flavus infection in susceptible and resistant inbreds.

Nearly everything on Earth harbors a microbiome. A microbiome is a community of microbes (bacteria, fungi, and viruses) with potential to form complex networks that involve mutualistic and antagonistic interactions. Resident microbiota on/in an organism are determined by the external environment, both biotic and abiotic, and the intrinsic adaptability of each organism. Although the maize microbiome has been characterized, community changes that result from the application of fungal biocontrol strains, such as non-aflatoxigenic Aspergillus flavus, have not. We silk channel inoculated field-grown maize separately with a non-aflatoxigenic biocontrol strain (K49), a highly toxigenic strain (Tox4), and a combination of both A. flavus strains. Two maize inbreds were treated, A. flavus-susceptible B73 and A. flavus-resistant CML322. We then assessed the impacts of A. flavus introduction on the epibiota and endobiota of their maize kernels. We found that the native microbial communities were significantly affected, irrespective of genotype or sampled tissue. Overall, bacteriomes exhibited greater diversity of genera than mycobiomes. The abundance of certain genera was unchanged by treatment, including genera of bacteria (e.g., Enterobacter, Pantoea) and fungi (e.g., Sarocladium, Meyerozyma) that are known to be beneficial, antagonistic, or both on plant growth and health. Beneficial microbes like Sarocladium that responded well to A. flavus biocontrol strains are expected to enhance biocontrol efficacy, while also displacing/antagonizing harmful microbes.

Host cell-type and pathogen-specific immunomodulatory functions of macrophage migration inhibitory factor (MIF) in infectious keratitis

Therapeutic management of inflammation in infectious keratitis (IK) requires new strategy and targets for selective immunomodulation. Targeting host cell-type specific inflammatory responses might be a viable strategy to curtail unnecessary inflammation and reduce tissue damage without affecting pathogen clearance. This study explores the possibility of pathogen and host cell-type dependent differences in the inflammatory pathways relevant in the pathogenesis of IK. Human corneal epithelial cell line (HCEC) and phorbol 12-myristate-13 acetate (PMA) differentiated THP-1 macrophage line were infected with either Aspergillus flavus conidia or Acanthamoeba castellanii trophozoites and the elicited inflammatory responses were studied in terms of gene expression and secretion of proinflammatory factors interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-α) and an upstream inflammatory regulator and mediator protein-the Macrophage Migration Inhibitory Factor (MIF). Given the pleotropic mode of MIF function in diverse cell types relevant in many human diseases, we tested if MIF driven responses to infection is different in HCECs and THP-1 macrophages by studying its expression, secretion and involvement in inflammation by siRNA mediated knockdown. We also examined IK patient tear samples for MIF levels. Infection with A. flavus or A. castellanii induced IL-8 and TNF-α responses in HCECs and THP-1 macrophages but to different levels. Our preliminary human data showed that the level of secreted MIF protein was elevated in IK patient tear, however, MIF secretion by the two cell types were strikingly different in-vitro, under both normal and infected conditions. We found that HCECs released MIF constitutively, which was significantly inhibited with infection, whereas THP-1 macrophages were stimulated to release MIF during infection. MIF gene expression remained largely unaffected by infection in both the cell lines. Although MIF in HCECs appeared to be intracellularly captured during infection, MIF knockdown in HCECs associated with a partial reduction of the IL-8 and TNF-α expression produced by either of the pathogens, suggesting a pro-inflammatory role for MIF in HCECs, independent of its canonical cytokine like function. In contrast, MIF knockdown in THP-1 macrophages accompanied a dramatic increase in IL-8 and TNF-α expression during A. castellanii infection, while the responses to A. flavus infection remained unchanged. These data imply a host cell-type and pathogen specific distinction in the MIF- related inflammatory signaling and MIF as a potential selective immunomodulatory target in infectious keratitis.

Physical, chemical and microbial quality of peanuts collected from different sources of the marketing chain

Groundnut is a healthy food by the presence of calcium and magnesium, vitamin E, oleic acids, fibre, arginine, and phenolic compounds. Relates to human health, however, peanut is susceptible to Aspergillus flavus infection and aflatoxin contamination. The study aims to evaluate the physical and chemical quality, aflatoxin B1 contamination, and phenolic content of peanuts collected from farmers, collectors, wholesalers, and retailers at Sinjai District, South Sulawesi, Indonesia during wet season. The results showed that intact seeds reduced from 82.8% in farmer’s level to 75.9% in retailers at traditional markets, as the increase of shrivelled and damage kernels. The average moisture content in marketing chain was 9.5%, which was higher than 8% as recommended. The infection of A. flavus was high in big traders and drastically reduced in retailer level. Aflatoxin B1 contamination went up from farmer to retailer beyond the permitted level of 15 µg kg−1. Total phenolic contents of peanuts collected from marketing chain ranged from 42.6 – 88.6 mg GAE/g that 60-80% lower than the ones contained by the newly harvested peanuts (81.9 – 116.6 mg GAE/g). Reasonable low physical quality and potentially high aflatoxin contamination of peanuts in retailer level suggest the essential of good handling practices to be introduced to peanut stakeholders.