Aspergillus Species Research Articles

HALOPHILIC ASPERGILLUS SPECIES IN EXTREME ENVIRONMENTS: PHYSIOLOGY, ADAPTATIONS, AND APPLICATIONS

Salt is essential for growth at certain limits, but life dwelling in harsh, salty environments are the halophiles. Studies on the halophilic bacteria, archaea, and fungi are reported around different locations, but the fungus Aspergillus species is a predominant halophilic eukaryote reported in various research works. They have been reported from an environment with high salt concentrations. Halophilic Aspergillus species grow better in harsh conditions and have an exciting opportunity for research and application ahead of them. Their potential in biotechnology, together with their special capacity for adaptation to harsh settings, makes them precious in many sectors from environmental science, to biotechnology, and even in bioremediation settings. Therefore, this work review the physiology and unique adaptations of halophilic Aspergillus species in extreme environments, biomolecule produces and their applications in different areas and future prospects.

FREQUENCY OF ALLERGIC BRONCHOPULMONARY ASPERGILLOSIS (ABPA) IN PATIENTS ADMITTED WITH ACUTE EXACERBATION OF ASTHMA IN A TERTIARY CARE HOSPITAL IN KARACHI: A PROSPECTIVE OBSERVATIONAL STUDY

Allergic Bronchopulmonary Aspergillosis (ABPA) is a hypersensitivity reaction to Aspergillus species and often complicates the clinical course of asthma, leading to more severe exacerbations and poor disease control. Despite its clinical relevance, the prevalence of ABPA in asthma patients remains under-reported, especially in developing countries like Pakistan. Objective: This study aimed to determine the prevalence of ABPA among patients admitted with acute exacerbations of asthma at a tertiary care hospital in Karachi, Pakistan. Methods: A prospective observational quantitative study was conducted at the Department of Pulmonary Medicine, Aga Khan Hospital University Karachi, Pakistan from January 2023 to December 2023 in Karachi. The study included 150 isolated patients of either gender, aged between 18 and 80 years, with a clinical diagnosis of asthma or those eligible for spirometry. Data collected included demographic details, past medical history, pulmonary function test results, and serological data for ABPA diagnosis. The presence of ABPA was confirmed by elevated serum total IgE concentration, specific IgE to Aspergillus fumigatus, and radiological findings. Statistical analysis was conducted using SPSS, with p-values < 0.05 considered statistically significant. Results: The study revealed an overall prevalence of ABPA in 20% of the 150 patients with acute asthma exacerbations. Serum total IgE concentration was significantly higher in the ABPA group (450 IU/mL) compared to the non-ABPA group (p < 0.05). Additionally, patients with ABPA had significantly lower FEV1 (60% predicted) compared to those without ABPA (p < 0.05). Conclusion: The study highlights a notable prevalence of ABPA among asthma patients experiencing acute exacerbations. This underscores the importance of raising clinical awareness and implementing timely diagnostic strategies for ABPA in asthma management, which could significantly improve patient outcomes.

Alligamycin A, an antifungal β-lactone spiroketal macrolide from Streptomyces iranensis

Fungal infections pose a great threat to public health and there are only four main types of antifungal drugs, which are often limited with toxicity, drug-drug interactions and antibiotic resistance. Streptomyces is an important source of antibiotics, represented by the clinical drug amphotericin B. Here we report the discovery of alligamycin A (1) as an antifungal compound from the rapamycin-producer Streptomyces iranensis through genome-mining, genetics and natural product chemistry approaches. Alligamycin A harbors a unique chemical scaffold with 13 chiral centers, featuring a β-lactone moiety, a [6,6]-spiroketal ring, and an unreported 7-oxo-octylmalonyl-CoA extender unit incorporated by a potential crotonyl-CoA carboxylase/reductase. It is biosynthesized by a type I polyketide synthase which is confirmed through CRISPR-based gene editing. Alligamycin A displayed potent antifungal effects against numerous clinically relevant filamentous fungi, including resistant Aspergillus and Talaromyces species. β-Lactone ring is essential for the antifungal activity since alligamycin B (2) with disruption in the ring abolished the antifungal effect. Proteomics analysis revealed alligamycin A potentially disrupts the integrity of fungal cell walls and induces the expression of stress-response proteins in Aspergillus niger. Discovery of the potent antifungal candidate alligamycin A expands the limited antifungal chemical space.

Genomic localization bias of secondary metabolite gene clusters and association with histone modifications in Aspergillus

Abstract Fungi are well-known producers of bioactive secondary metabolites (SMs), which have been exploited for decades by humankind for various medical applications like therapeutics and antibiotics. SMs are synthesized by biosynthetic gene clusters (BGCs) – physically co-localized and co-regulated genes. Because BGCs are often regulated by histone post-translational modifications (PTMs), it was suggested that their chromosomal location is important for their expression. Studies in a few fungal species indicated an enrichment of BGCs in sub-telomeric regions; however, there is no evidence that BGCs with distinct genomic localization are regulated by different histone PTMs. Here, we used 174 Aspergillus species covering 22 sections to determine the correlation between BGC genomic localization, gene expression and histone PTMs. We found a high abundance and diversity of SM backbone genes across the Aspergillus genus, with notable unique genes within sections. Being unique or conserved in many species, BGCs showed a strong bias for being localized in low-synteny regions, regardless of their position in chromosomes. Using chromosome-level assemblies, we also confirmed a significantly biased localization in sub-telomeric regions. Notably, SM backbone genes in sub-telomeric regions and about half of those in low-synteny regions exhibit higher gene expression variability, likely due to the similar higher variability in H3K4me3 and H3K36me3 histone PTMs; while variations in histone H3 acetylation and H3K9me3 are not correlated to genomic localization and expression variation, as analyzed in two Aspergillus species. Expression variability across four Aspergillus species further supports that BGCs tend to be located in low-synteny regions and that regulation of expression in those regions likely involves different histone PTMs than the most commonly studied modifications.

Evaluation of metagenomic next-generation sequencing (mNGS) combined with quantitative PCR: cutting-edge methods for rapid diagnosis of non-invasive fungal rhinosinusitis.

Fungal rhinosinusitis is a significant and growing health concern in arid regions, with an increasing incidence over recent decades. Without timely and appropriate management, it can lead to severe complications, including potential intracranial spread. This study aims to establish efficient and rapid diagnostics for non-invasive fungal rhinosinusitis (FRS), addressing the challenge of its difficult-to-culture diagnosis. Twenty-eight patients suspected of FRS were studied using endoscopic sinus surgery to obtain tissue samples for histopathology, direct microscopy, fungal culture, quantitative PCR (qPCR) and metagenomic next-generation sequencing (mNGS) detection. A patented qPCR targeting prevalent Aspergillus species was evaluated. The patient cohort had a male-to-female ratio of 9:14, with disease duration up to 50 years. Histopathologically, 23 out of 28 cases were positive. Fungal culture exhibited a sensitivity of 21.74%, with one false positive. qPCR and mNGS showed 100% sensitivity and specificity, with a 100% consistency rate for identification at the species level (23/23), and potential detection of cases with co-infections. The most common pathogen was A. flavus, followed by A. fumigatus and A. niger. Two cases involved mixed infections of A. fumigatus and A. flavus. qPCR and mNGS proved effective in rapidly identifying fungi from fresh sinus tissue that are challenging to culture, surpassing conventional methods. However, further evaluation and optimization with a larger cohort of patients are necessary. Histopathology is still recommended to confirm the clinical significance of the detected fungal species.

The underrepresented quinolinone alkaloids in genera Penicillium and Aspergillus: structure, biology, and biosynthetic machinery.

Quinolone alkaloids are N-heterocycles with extensive structural diversity, mainly derived from in fungi from anthranilic acid and amino acids as precursors with a wide range of biological activities as antifungal, antimicrobial, anti-inflammatory, and insecticidal activities. The quinolone basic skeleton comprised of either 2-quinolones or 4-quinolones generated more than one hundred compounds. Several reviews discussed quinolones; particularly, the fluoroquinolones, yet few studies tackled natural quinolones. Many of these quinolones were not assayed for their antimicrobial potential despite their unique stereospecificity, which can supersede synthetic quinolones if their discovery is coupled with OMICS techniques, biochemical and molecular strategies as heterologous expression to maximize their yield. Herein, we conducted a comprehensive review of the quinolone's family in Aspergillus and Penicillium species, the exclusive producers of quinolones whether they are soil, endophytic or marine derived highlighting their isolation, chemical structures, pharmacological effects, structure activity relationships if any, and biosynthetic machinery. We believe that our initiative will pave the way for further development of natural quinolones as future antimicrobial agents.

Three new species of Talaromyces sect. Talaromyces discovered in China.

Talaromyces species play an important role in the nutrient cycle in natural ecosystems, degradation of vegetal biomass in industries and the implications in medicine. However, the species diversity of this genus is still far from fully understood. The polyphasic taxonomic approach integrating morphological comparisons and molecular phylogenetic analyses based on BenA, CaM, Rpb2 and ITS sequences was used to propose three new Talaromyces species. Three new species of sect. Talaromyces isolated from soil are proposed, namely, T. disparis (ex-type AS3.26221), T. funiformis (ex-type AS3.26220) and T. jianfengicus (ex-type AS3.26253). T. disparis is unique in low growth rate, velvety texture, limited to moderate sporulation, biverticillate, monoverticillate and irregular penicilli bearing a portion of abnormally large globose conidia, it has no close relatives in phylogeny. Being a member of T. pinophilus complex, T. funiformis produces mycelial funicles on Czapek yeast autolysate agar (CYA), 5% malt extract agar (MEA) and yeast extract (YES), sparse sporulation on Czapek agar (Cz), CYA, MEA and YES while abundant on oatmeal agar (OA), bearing appressed biverticillate penicilli and globose to pyriform conida with smooth to finely rough walls. T. jianfengicus belongs to T. verruculosus complex, is characterized by velvety colony texture with moderate to abundant elm-green conidia en masse, producing biverticillate penicilli, globose conidia with verrucose walls. It is now a common practice in establishing new species of Aspergillus, Penicillium and Talaromyces based on morphological characters and phylogenetic analyses of BenA, CaM, Rpb2 and ITS sequences. The proposal of the three novelties of Talaromyces in this article is not only supported by their morphological distinctiveness, but also confirmed by the phylogenetic analyses of the concatenated BenA-CaM-Rpb2 and BenA-CaM-ITS, as well as the individual BenA, CaM, Rpb2 and ITS sequence matrices.

Survey on the occurrence of Aspergillus section Nigri species in grapes cultivated in Umbria (central Italy) and influence of several factors on their distribution

AbstractSecondary bunch rots caused by Aspergillus species belonging to the section Nigri, commonly called black aspergilli, pose a serious threat to grapes yield and quality. Due to their ability to produce ochratoxin A (OTA), they are considered the primary source of contamination of this mycotoxin in grapes. In this study, a three-year survey was realized to assess the occurrence of black aspergilli in grapes harvested in the Umbria region, a very important grapevine cultivation area in central Italy, by fungal isolation and phylogenetic analysis. In addition, the influence of growing season, vineyard location, farming system and grapes growth stages on black aspergilli distribution was examined. Phylogenetic analysis of the 208 obtained isolates showed the presence of three black aspergilli species: Aspergillus tubingensis, Aspergillus welwitschiae and Aspergillus uvarum. Interestingly, A. carbonarius, one of the most important OTA producers, was not detected in the surveyed years. A. tubingensis, whose ability to produce OTA is controversial, was always the most isolated species followed by A. welwistichiae (OTA producer). The species A. uvarum (unable to produce OTA) was detected only in one surveyed year with a low incidence. A. tubingensis was always the species with the highest incidence, regardless of location, and farming system. Growth stage appeared to influence the incidence of the three species, that, in the case of A tubingensis, was lower during setting in comparison to berries pea-size and berries harvest-ripe. Finally, in the setting and berries pea-size stages, a stereomicroscope analysis, showed that flower debris was the substrate from which black aspergilli mainly developed prior to colonizing berries and bunches.

Survival Dynamics of Invasive Fungal Diseases in Pediatric Hemato-Oncology Patients at a Tertiary Medical Facility in Mexico from July 2020 to July 2023

Abstract Background Invasive fungal diseases (IFD) have been increasing in prevalence over the past two decades, with filamentous fungi being the most common cause. However, candidiasis remains the predominant etiology of infection, especially in cases of neutropenic fever accompanied by neutropenic colitis. The prevalence of infections caused by Aspergillus species, Mucor species, Fusarium, and other species is higher among individuals with severe and extended neutropenia and those who have undergone hematopoietic progenitor cell transplantation. Methods A retrospective, descriptive, observational study was conducted to identify cases of patients diagnosed with invasive fungal diseases, categorizing them as possible, probable, or confirmed. In our comprehensive analysis of cases, we prioritize the examination of diseases induced by filamentous fungi, while considering the specific chemotherapy regimen administered and the particular oncological condition. Results The predominant etiology observed was invasive aspergillosis, followed by mucormycosis. A total of 18 cases suggestive of invasive Aspergillosis were identified, but clinical or histopathological investigations were not conducted due to limitations. The majority of cases were pulmonary, accounting for 92% of cases, while rhinosinusal involvement was identified in 8%. Factors such as clinical characteristics, imaging studies, serum galactomannan determination, and microbiological culture were considered. The patient survival rate was found to be 86.7%, with an average treatment duration of six weeks. A mortality rate of 3.7% was observed due to the underlying disease during the consolidation phase of invasive fungal diseases. Conclusion In our study, invasive aspergillosis emerged as the predominant invasive fungal disease in pediatric hemato-oncology patients. Despite challenges in conducting comprehensive investigations, our findings underscore the importance of timely diagnosis and management. The 86.7% survival rate reflects the efficacy of the treatment approach employed, while the observed mortality emphasizes the impact of underlying diseases on outcomes. This study contributes valuable insights to the understanding and improvement of survival dynamics in pediatric patients facing invasive fungal diseases.

Bilateral chronic cavitary pulmonary aspergillomas in an adult patient with recurrent tuberculosis: a case report and literature review

BackgroundAspergillomas are globular growths of Aspergillus fumigatus, a benign aspergillosis of the lungs. It usually affects patients who are immunocompromised and have anatomically defective lung structures. The majority of aspergilloma cases are asymptomatic, despite the fact that 10% of cases spontaneously resolve. Most patients do not have any symptoms from their lesions. Direct serological or microbiological evidence of an Aspergillus species along with radiologic evidence is required for the diagnosis of an aspergilloma.CaseWe describe a 35-year-old adult Oromo male patient who had been experiencing night sweats, an intermittent productive cough with sparse whitish sputum, loss of appetite, and easy fatigability for 3 months. At 5 years prior, he received treatment for pulmonary tuberculosis that was smear-positive and was subsequently certified healed. Objectively, he was tachypneic and had intercostal, subcostal, and supraclavicular retractions with symmetric chest movement. A high-resolution computed tomography scan revealed bilateral apical cavitary lesions with core soft tissue attenuating spherical masses and an air crescentic sign suggestive of aspergillomas, which were confirmed by sputum light microscopic examination. The patient was managed with antibiotics and antifungals.ConclusionAspergilloma is a symptom of chronic pulmonary aspergillosis, a category of lung disorders caused by a persistent Aspergillus infection. Primary aspergillomas are uncommon and frequently occur in people with compromised immune systems. A prolonged cough, fever, chest pain, and hemoptysis are all symptoms of pulmonary aspergillomas. The majority of the time, pulmonary aspergillosis is difficult to identify. Despite high mortality and morbidity rates, surgery is still the most effective treatment for pulmonary aspergilloma.

Biodiversity of Aspergillus Species and Their Mycotoxin Production Potential in Dry Meat.

This study aimed to examine fungi diversity in dried beef meat sold in Ekiti State, characterize the isolated fungi, and determine the aflatoxin-producing ability of the Aspergillus fungi in the samples. Dried beef meat was collected from different markets in Ekiti State and screened for the presence of filamentous fungi using molecular methods. Samples were cultured aseptically on potato dextrose agar (PDA) for fungi isolation, and molecular identification was performed using DNA extraction, Polymerase chain Reaction (PCR), ITS-1/ITS-4 primer pair, and nucleotide sequencing. The results obtained indicated a range of filamentous fungi genera including Aspergillus, Rhizopus, Penicillium, Fusarium, Cladosporium, Alternaria, and other fungi species contaminating the dried meat at (43%), (42%), (3%), (2%), (2%), (1%), and (7%), respectively. High incidences were recorded for Aspergillus flavus, Aspergillus niger, and Aspergillus fumigatus in most of the screened samples. Aspergillus flavus accounted for (24.7%) of all the Aspergillus species isolated with the presence of the gene needed for aflatoxin production. The occurrences of these filamentous fungal species pose a cause for concern, as most of these fungal species are known producers of certain toxic substances. Maximum likelihood phylogenetic analysis showed a high similarity index score, which indicated a good relationship between isolated Aspergillus Species and the closely related strains from GenBank, isolated from different sources and countries. The implication of this study is that consumer health may be at risk through exposure to contaminated dried meat.

The Real-World Effectiveness of Antifungals in People with Cystic Fibrosis and Aspergillus-Positive Cultures.

The pathogenicity of Aspergillus in the cystic fibrosis (CF) airway is debated, leading to unclear clinical benefit of antifungal therapy for Aspergillus infection. To determine the real-world effectiveness of antifungal use in people with CF (PwCF) with Aspergillus species in the United States. We conducted a retrospective cohort study evaluating the association of antifungal use and respiratory outcomes in PwCF and Aspergillus positive cultures using the Cystic Fibrosis Foundation patient registry. Marginal structural models using inverse-probability treatment weighted estimators were used to test if antifungal exposure was associated with forced expiratory volume in one second percent predicted (FEV1pp) and pulmonary exacerbation rate, while controlling for fixed and time-varying confounders. We conducted sensitivity analyses on individuals with persistent Aspergillus and without concomitant allergic bronchopulmonary aspergillosis (ABPA). A total of 14,754 individuals with Aspergillus positive cultures between 2006 and 2019 were identified. Antifungals were prescribed to 3,575 (24.2%) unique PwCF during the study period. Antifungal use was not associated with FEV1pp (adjusted estimate -0.96 percentage points, 95% CI -2.21,0.29). Antifungal use was associated with 29% increased rate of pulmonary exacerbations requiring intravenous (IV) antibiotics (adjusted IRR=1.29, 95% CI 1.22, 1.37). In sensitivity analyses limited to individuals without ABPA< antifungals were associated with 1.88 lower FEV1pp (95% CI -3.35, -0.41) and an increased rate of pulmonary exacerbations (adjusted IRR= 1.30, 95% CI 1.21,1.40). Whereas, in patients with persistent Aspergillus and persistent Aspergillus without concomitant ABPA, antifungals were not associated with FEV1pp. Antifungal therapy in PwCF and Aspergillus positive cultures was not associated with improvements in FEV>1pp. While antifungal therapy was associated with increased risk for pulmonary exacerbations, this could reflect confounding by severity of disease. Randomized clinical trials examining the clinical efficacy of antifungals in Aspergillus infections are warranted.

Overcoming amphotericin B resistance in Candida auris using the antiemetic drug rolapitant.

The emergence of Candida auris poses a significant health challenge that has led to a new era of multidrug-resistant fungal infections. Invasive infections caused by C. auris are usually associated with remarkable morbidity and mortality. For many years, amphotericin B (AmB) remained the most efficient and the last line of treatment against most hard-to-treat fungal infections. However, strains of C. auris possess extraordinary resistance to most antifungal agents, including AmB. In this study, we screened ~2,600 FDA-approved drugs and clinical compounds to identify the antiemetic drug rolapitant as a promising enhancer to AmB against C. auris. Rolapitant exhibited potent synergistic interactions with AmB against all tested (29/29) C. auris isolates. In a time-kill assay, rolapitant restored the fungicidal activity of AmB within 4 h. Additionally, the synergistic relationship between rolapitant and AmB was observed against other medically crucial Candida, Cryptococcus, and Aspergillus species. A transcriptomic study revealed that exposure to rolapitant affects oxidation reduction processes, ion transporters, and ATP production. Rolapitant triggers an elevation in cytosolic and mitochondrial calcium levels and induces oxidative stress within fungal cells. An ATP luminescence assay confirmed that rolapitant, at sub-inhibitory concentrations, significantly interfered with ATP production in C. auris. Moreover, rolapitant enhanced the in vivo activity of AmB in a mouse model of disseminated C. auris infection, as the combination reduced the fungal burden in murine kidneys by ~1 log (~90%) colony forming units. Our findings warrant further investigation of using rolapitant to overcome AmB resistance in C. auris and other fungal species.

The activating receptor NKG2D is an anti-fungal pattern recognition receptor

NKG2D is a central activating receptor involved in target recognition and killing by Natural Killer and CD8+ T cells. The known role of NKG2D is to recognize a family of self-induced stress ligands that are upregulated on stressed cells such as cancerous or virally infected cells. Fungal pathogens are a major threat to human health, infecting more than a billion patients yearly and becoming more common and drug resistant. Here we show that NKG2D plays a critical role in the immune response against fungal infections. NKG2D can recognize fungal pathogens from most major families including Candida, Cryptococcus and Aspergillus species, and mice lacking NKG2D are extremely sensitive to fungal infections in models of both invasive and mucosal infections, making NKG2D an anti-fungal pattern recognition receptor.

SPECIES IDENTIFICATION AND IN VITRO ANTIFUNGAL SUSCEPTIBILITY TESTING OF ASPERGILLUS ISOLATED FROM VARIOUS CLINICAL SAMPLES

Objectives: Aspergillus is ubiquitous mold species present in environment in the form of spores. Infection due to Aspergillus is uncommon in immunocompetent individuals unless they possess any abnormality or have undergone any treatment with corticosteroids. In immunocompromised individuals, infection by this fungus is common among people with prolonged neutropenia, transplants, and human immunodeficiency virus infection. The symptoms are diverse, ranging from allergic reactions to invasive aspergillosis and life-threatening complications. The aim of this study is to isolate and identify Aspergillus species obtained from various clinical specimens and perform antifungal susceptibility testing (AFST). Methods: A total of 200 isolates in which positive direct microscopic findings correlated well with culture growth for Aspergillus were included. Antifungal susceptibility was performed by micro broth dilution technique according to clinical laboratory standard institute M38-A2 guidelines. Results: Aspergillus flavus was found to be predominant species followed by Aspergillus fumigatus. AFST was performed, where all Aspergillus strains exhibited low minimum inhibitory concentration (MIC) and minimum effective concentration (MEC) values for most of antifungal drugs tested except for one strain of A. flavus, which exhibited high MIC for voriconazole and high MEC for caspofungin. Conclusion: Polyenes, azoles, and echinocandin resistance are emerging in many parts of the world. Therefore, continued application of AFST combined with morphological characterization for species identification is critical in detecting the emergence of resistance among various Aspergillus species to reduce mortality, morbidity, and overcome treatment failure.

Antibacterial and anticancer potential of bioactive compounds and secondary metabolites of endophytic fungi isolated from Anethum graveolens.

Fungal endophytes are known to produce bioactive chemicals and secondary metabolites that are often identical to those produced by their host plants. The main objective of the current study was to isolate and identify endophytic fungi associated with the medicinal plant Anethum graveolens, and to investigate their potential antibacterial and anticancer properties. The ethyl acetate extracts from the isolated endophytic fungi, as well as the host plant A. graveolens, were subjected to bioactivity assays to evaluate their antibacterial and anticancer potential against multi-drug resistant bacterial strains and the human hepatocellular carcinoma cell line HepG2. The endophytic fungi isolated and identified from the A. graveolens samples included Diaporthe, Auxarthron, Arthrinium, Aspergillus, Microsporum, Dothiorella, Trichophyton, Lophiostoma, Penicillium, and Trichoderma species. The minimum inhibitory concentration (MIC) assay revealed that the A. graveolens extract exhibited the strongest antibacterial activity, with an MIC value of 4 μg/ml, followed by the Trichoderma sp. (5 μg/ml) and Penicillium sp. (6 μg/ml) extracts. Additionally, the crude extracts of Trichoderma sp., Penicillium sp., and Fusarium sp. demonstrated high anticancer activity against HepG2 cells, with inhibition rates ranging from 89 to 92% at a concentration of 50 μg/ml. Interestingly, the A. graveolens extract showed the most potent anticancer activity, with a 95% inhibition rate against HepG2 cells at the same concentration. These findings highlight the significant potential of endophytic fungi associated with A. graveolens, as a source of bioactive compounds with promising antibacterial and anticancer properties. The results reinforce the hypothesis that medicinal plants and their endophytic fungi can serve as an attractive alternative for the development of novel therapeutic agents, potentially offering a more sustainable and less harmful approach to disease management compared to traditional chemical-based methods.

Unmasking aflatoxin hazards in maize for human consumption: investigating maize contamination in Mwanza Markets, Tanzania

Background: Aflatoxin arises from toxigenic Aspergillus species, which infect maize because of improper storage, insufficient drying, extended storage periods, and suboptimal farming practices. This study investigated the aflatoxin contamination in maize for human consumption within specific markets of Mwanza, Tanzania. Methodology: A cross-sectional study was conducted from June to August 2021. Maize samples were analyzed using ELISA followed by descriptive statistical data analysis. Results: A total of 90 maize merchants from 8 local markets were involved. Their mean age was 34.7 (± 6.7) years, majority were male (51 out of 90, 56.7%). Among the vendors, the majority were not aware of aflatoxin (62 out of 90, 68.9%), stored maize in polypropylene woven bags (62 out of 90, 68.98%) and dried the maize before storage (86 out of 90, 95.6%). Out of the 90 samples, 10 (11.1%) had aflatoxin contamination above 1µg/kg, ranging from 1.01µg/kg to 33.4µg/kg with 3 (3.3%) being contaminated above the acceptable standard (≥10µg/kg). Conclusion: The levels of aflatoxin contamination in maize for human consumption exceed the established safety thresholds. Governments in lower and middle-income nations should intensify enforcement of regulations aimed at enhancing community awareness regarding aflatoxin risks and minimizing contaminations. Keywords: Maize vendors; maize contamination; polypropylene woven bags; Aflatoxin.

Essential oils from Cuminum cyminum and Laurus nobilis and their principal constituents: evaluation of antifungal and antimycotoxigenic potential in Aspergillus species.

The antifungal and antimycotoxigenic activities of the essential oils (EO) from Cuminum cyminum and Laurus nobilis, and their respective principal compounds, cuminaldehyde and 1,8-cineole, were evaluated against fungi of the genus Aspergillus: A.carbonarius, A.niger, A.ochraceus and A.westerdijkiae. The antifungal activity was determined by the contact method and the mycelial growth of the fungi was evaluated. Scanning Electron Microscopic (SEM) images were obtained to suggest modes of action of the compounds analyzed. The antimycotoxigenic activity was determined by HPLC. A.carbonarius was completely inhibited by cumin EO (500 µL L-1), by laurel EO and by cuminaldehyde (5000 µL L-1). The cumin EO (500 µL L-1) completely inhibited the growth of A.niger. All the samples inhibited the mycelial growth of A.ochraceus, especially cumin EO and cuminaldehyde (250 µL L-1). A.westerdijkiae was completely inhibited by cumin EO and cuminaldehyde (1000 µL L-1), by laurel EO and 1,8-cineole (10000 µL L-1). A decrease in the production of ochratoxin A (OTA) was observed post-treatment, except in A. ochraceus, only inhibited by laurel EO. SEM images showed morphological changes in fungal structures and spore inhibition post-treatment. The results confirmed the antifungal and antimycotoxigenic effect of EO and their principal constituents on fungi evaluated.

Bioprospecting for sustainable and eco-friendly bioproducts: A case study of multi-enzyme production by soil microbes

Microbial multi-enzyme production is a promising research area involving microbes that can simultaneously synthesize numerous enzymes for the degradation of substrates with environmental sustainability and other industrial applications as the focus. During this study, we isolated, screened, and identified some multi-enzyme-producing microbes from three soil sites in Ibadan: Apete Dumpsite (ADS); Botanical Garden University of Ibadan- (BGUI); and Eleyele Cassava Processing Field- (ECPF). Precisely 500 g of soil were collected per point at different depths (0–10, 10–20, and 20–30 cm) and further analyzed. The microbial load and type and enzyme assays were determined. The highest average microbial count (6.9 × 108 CFU/g) was recorded in the ECPF soil sample at 0–10 cm depth, while the lowest microbial count of 3.3 × 105 CFU/g at 20–30 cm soil depth in BGUI. Multi-enzyme-producing microbes were identified phenotypically and molecularly. This study revealed an inverse relationship between microbial community composition and soil depth. Bacterial and fungal genera had higher species richness, biodiversity, and evenness than yeast from all sampled points. With significant amylolytic, proteolytic, lipolytic, cellulolytic, and pectinolytic activities, 22 of the 193 isolates were identified as multienzyme producers. The blasted 16S rRNA and ITS rRNA amplicon sequences compared with sequences in the NCBI gene bank identified Bacillus, Roseomonas, Aeromonas, Phanerochaete, Aspergillus, Fusarium, Trametes, and Rigidoporus species. Results from this study show that topsoils (0–10 cm), rich with organic matter, are good reservoirs of multienzyme-producing microorganisms- applicable for environmental sustainability and in other important industries for waste management, food processing, and biomaterial production.

A-273 Rapid, Portable Invasive Fungal Infection Diagnostic and Candida Antimicrobial Susceptibility Testing

Abstract Background Traumatic wounds are associated with a higher risk of invasive fungal infections (IFI), which lead to a significant increase in amputation or death. Actionable treatment decisions are hampered because true infections can be difficult to differentiate from external wound contaminates, and tissue biopsy and quantification of fungal load is required to determine if treatment is necessary, which currently takes several days. GeneCapture is developing the CAPTURE 60-minute, portable infection identification platform to detect infectious levels of common fungi including the genera Aspergillus, Fusarium, and Scedosporium, the family Herpotrichiellaceae, and the order Mucorales. The company is also pursuing rapid identification and antimicrobial susceptibility testing for Candida species from multiple infection types. Methods This study seeks to determine the Limit of Detection (LoD), sensitivity and specificity of the CAPTURE ID assay for fungal pathogens. Since tissue biopsy samples must be used to assess the presence of IFI in wounds, GeneCapture has developed a manual process for the crude homogenization of muscle tissue to allow this matrix to be used as the starting sample for the ID assay. Mock samples were tested for inclusivity and exclusivity on a series of IFI ID panels against multiple strains of the included fungi, against fungi not yet specifically detected on the panel, and against bacteria that commonly infect wounds. While the LoD for yeasts may be determined in CFU/mL, there is no similar, easy-to-define metric for molds. GeneCapture has developed a quantitative PCR method to detect the single copy beta-tubulin gene to roughly correlate fungal dry mass and nuclei number to assay signal for molds cultured in Potato Dextrose Broth. Determining beta-tubulin copy numbers for extracts from mock samples then allowed detection of the progression of IFI over the course of infection. Lastly, antimicrobial susceptibility testing (AST) was performed on two species of Candida to validate utilizing GeneCapture’s rapid phenotypic AST method for fungal infections. Results To date, the CAPTURE ID panel has been tested against 27 included or excluded strains of fungi or bacteria with 97% sensitivity and 100% specificity. The current LoD for mold organisms varies from approximately 1,000 nuclei for Aspergillus species, to 100,000 nuclei for Fusarium species. Additional work to understand this range is underway. Lastly, we have correctly determined the susceptibility of Candida species using our novel approach within 4-6 hours. Conclusions GeneCapture’s ID and AST technology offer a unique solution to address the increasing prevalence of fungal infections. Our platform can identify the most common fungal components in a wound within 60 minutes of receiving a tissue biopsy sample. Candida infections occur across multiple matrices and rapidly identifying the species of Candida and then determining its phenotypic susceptibility profile will have a large impact on treating these difficult pathogens.