Flavonoids Modulate the Accumulation of Toxins From Aspergillus flavus in Maize Kernels

Aspergillus flavus is an opportunistic fungal pathogen capable of producing aflatoxins, potent carcinogenic toxins that accumulate in maize kernels after infection. To better understand the molecular mechanisms of maize resistance to A. flavus growth and aflatoxin accumulation, we performed a high-throughput transcriptomic study in situ using maize kernels infected with A. flavus strain 3357. Three maize lines were evaluated: aflatoxin-contamination resistant line TZAR102, semi-resistant MI82, and susceptible line Va35. A modified genotype-environment association method (GEA) used to detect loci under selection via redundancy analysis (RDA) was used with the transcriptomic data to detect genes significantly influenced by maize line, fungal treatment, and duration of infection. Gene ontology enrichment analysis of genes highly expressed in infected kernels identified molecular pathways associated with defense responses to fungi and other microbes such as production of pathogenesis-related (PR) proteins and lipid bilayer formation. To further identify novel genes of interest, we incorporated genomic and phenotypic field data from a genome wide association analysis with gene expression data, allowing us to detect significantly expressed quantitative trait loci (eQTL). These results identified significant association between flavonoid biosynthetic pathway genes and infection by A. flavus. In planta fungal infections showed that the resistant line, TZAR102, has a higher fold increase of the metabolites naringenin and luteolin than the susceptible line, Va35, when comparing untreated and fungal infected plants. These results suggest flavonoids contribute to plant resistance mechanisms against aflatoxin contamination through modulation of toxin accumulation in maize kernels.

Cutlink Cleaning Head with a Spreading Feature for Biological Sprout Control

The ability of deciduous trees to sprout efficiently after cutting is problematic in young forests where the target is to cultivate coniferous trees for industry. Since the use of chemicals has been restricted, new alternatives are needed. One potential and environmentally friendly option is biological sprout control that is based on the use of a white-rot fungus, Chondrostereum purpureum (Pers. Ex Fr.) Pouzar. This method has been efficient in earlier investigations when performed manually, but efficient, fully mechanized devices which are able to cut and treat stumps with a fungus are still unavailable. Therefore, the efficacy of biological sprout control conducted with a Cutlink cleaning head equipped with a spreading feature was studied in two young Norway spruce (Picea abies (L.) H. Karst.) forests in central Finland.Sample plots for the control (cutting deciduous saplings only) and fungal treatment (cutting and spreading fungal inoculum on fresh stump surfaces) were established, and the ability of the Cutlink cleaning head in preventing sprouting of silver and downy birch (Betula pendula Roth and B. pubescens Ehrh., respectively) in the sample plots was investigated for two years.In the near vicinity of cultivated Norway spruce, the proportion of cut deciduous saplings varied from 50–60% after the Cutlink operation. The average mortality of silver and downy birch stumps in the fungal treatment plots was ca. 40%, while stump mortality in the control, i.e., cutting only, was only ca. 13%, after two years. Stump mortality increased up to 73% if the stumps did not include old branches, i.e., the stump was cut to a low enough height.These results confirmed that the Cutlink cleaning head is a potential tool in young stand management operation but further development will be needed in working methods in order to achieve lower stump heights (no branches on the stump) and also to increase the proportion of cut saplings.

The Effects of Bioinoculants Based on Mycorrhizal and Trichoderma spp. Fungi in an Apple Tree Nursery under Replantation Conditions

Both mycorrhizal and Trichoderma spp. fungi are known for antagonistic effects against certain biological pathogens causing apple replant disease (ARD). The aim of this study was to assess the effectiveness of the bioinoculants based on endomycorrhizal and Trichoderma spp. fungi on the biological properties of soil as well as the parameters of the apple tree growths in a fruit tree nursery under replantation conditions. A two-year experiment was conducted on Jonagold apple trees grafted on to M.9 rootstock in western Poland. The trees were planted in the replant soil—from areas used for the production of apple trees, and in the crop rotation soil, that had not been used for nursery purposes before. A mycorrhizal inoculum and preparations containing Trichoderma spp. fungi were applied to the replant soil. Biological properties of the soil and the growth of the aerial and underground parts of the apple trees were assessed. The enzymatic (dehydrogenases and protease) and respiratory activity of the replant soil was significantly lower than that of the crop rotation soil. The apple trees grew worse when exposed to the ARD conditions. The effectiveness of applied bioinoculants in mitigating the effects of replantation in the nursery were shown. Both the treatment mycorrhization and the application of bioinoculants containing Trichoderma spp. increased the respiratory and enzymatic activity of the replant soil. The growth of the root system and the aerial parts of the trees (including leaves) was much better after the combined use of both types of fungi than in the replant soil that had not received the fungal treatment.

A marine fungus efficiently degrades polyethylene

Plastics pollution has been a global concern. Huge quantities of polyethylene (PE), the most abundant and refractory plastic in the world, have been accumulating in the environment causing serious ecological problems. However, the paucity of microorganisms and enzymes that efficiently degrading PE seriously impedes the development of bio-products to eliminate this environmental pollution. Here, by screening hundreds of plastic waste-associated samples, we isolated a fungus (named Alternaria sp. FB1) that possessing a prominent capability of colonizing, degrading and utilizing PE. Strikingly, the molecular weight of PE film decreased 95% after the fungal treatment. Using GC-MS, we further clarified that a four-carbon product (named Diglycolamine) accounted for 93.28% of all degradation products after the treatment by strain FB1. We defined potential enzymes that involved in the degradation of PE through a transcriptomic method. The degradation capabilities of two representative enzymes including a laccase and a peroxidase were verified. Lastly, a complete biodegradation process of PE is proposed. Our study provides a compelling candidate for further investigation of degradation mechanisms and development of biodegradation products of PE.

Efficacy of the Applied Natural Enemies on the Survival of Colorado Potato Beetle Adults

Colorado potato beetle Leptinotarsa decemlineata is among the most destructive pests of potatoes quickly developing resistance to traditional insecticides. In the present study, we tested the effect of various species and strains of entomopathogenic nematodes on CPB adults, and subsequently, the most effective nematodes were applied alone and in combination with entomopathogenic fungus B. bassiana in pots with potato plants and in the field and their effect on the number of emerging adults was evaluated. In the experimental infections, both the nematode invasion and pathogenicity were variable, and, in several strains, the mortality reached 100%. In pot experiments, soil application of nematodes S. carpocapsae 1343 and S. feltiae Jakub and fungus significantly decreased numbers of emerging CPB adults, while, after the application on leaves, only fungal treatment was effective. The field application of fungus B. bassiana significantly decreased the number of emerging CPB adults in comparison to control sites by ca. 30% while the effect of nematodes and the nematodes–fungus combination was not significant. In conclusion, we demonstrate the necessity of thorough bioassays to select the most effective nematode strains. Entomopathogenic nematodes have the potential to effectively decrease the emergence of CPB adults, but further research is needed to improve the effectiveness in the field.

Pseudomonas synergizes with fluconazole against Candida during treatment of polymicrobial infection

Polymicrobial infections are challenging to treat because we don't fully understand how pathogens interact during infection and how these interactions affect drug efficacy. Candida albicans and Pseudomonas aeruginosa are opportunistic pathogens that can be found in similar sites of infection such as in burn wounds and most importantly in the lungs of CF and mechanically ventilated patients. C. albicans is particularly difficult to treat because of the paucity of antifungal agents, some of which lack fungicidal activity. In this study, we investigated the efficacy of anti-fungal treatment during C. albicans-P. aeruginosa co-culture in vitro and co-infection in the mucosal zebrafish infection model analogous to the lung. We find that P. aeruginosa enhances the activity of fluconazole (FLC), an anti-fungal drug that is fungistatic in vitro, to promote both clearance of C. albicans during co-infection in vivo and fungal killing in vitro. This synergy between FLC treatment and bacterial antagonism is partly due to iron piracy, as it is reduced upon iron supplementation and knockout of bacterial siderophores. Our work demonstrates that FLC has enhanced activity in clinically relevant contexts and highlights the need to understand antimicrobial effectiveness in the complex environment of the host with its associated microbial communities.

Hemarthria compressa—Aspergillus niger—Trichoderma pseudokoningii Mediated Trilateral Perspective for Bioremediation and Detoxification of Industrial Paper Sludge

The present study was carried out to evaluate the effects of different fungal species on the metal uptake from paper sludge by Hemarthria compressa L. Paper sludge (PS) in various concentrations (0, 30% and 60%) were used with four treatments of two fungal species (F0 = Control, F1 = Aspergillus niger, F2 = Trichoderma pseudokoningii, F3 = A. niger + T. pseudokoningii). Paper sludge as rooting medium steadily influenced growth and physio-biochemical attributes of H. compressa in F0. Results revealed discrete variations in growth attributes with different PS concentrations and each fungal treatment. The maximum damages in ionic homeostasis (Na+, K+, Ca2+, Mg2+) due to PS toxicity were evident in parallel with declined chlorophyll concentration. The highest growth, total chlorophyll and biomass of the plants were observed when PS was treated with combined fungal strains (F3). Translocation factor decreased with F3 that is indicative of changes in Cd, Pb, and Cu movement to shoot from root. The plants with combined fungal treatment also showed greater catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD) activity. Ions, such as Ca, Mg, and Na, also increased gradually with combined fungal treatment. The correlation matrix displayed a close association among diverse fungal and PS levels with multiple plant attributes. PCA-Biplot confirmed the outcome of correlational analyses among different characters of H. compressa. The combined fungal mediate the extraction of heavy metals from the paper sludge by H. compressa recommends the high accumulation of heavy metal (HM) and possible reutilization of metal free sludge as a fertilizer, for application in cultivated fields. Furthermore, the effects of fungal species on HM attenuation in PS are linear and can be used in different habitats. Advancement in such research work will also be helpful in understanding the mechanisms and enhancing the ability of other native microbes to remediate metals.

287. Characteristics and Outcomes of COVID-19 Patients with Candidemia at a Community Hospital in Chicago

Background 1,416 patients with acute COVID-19 infection were admitted to our hospital in 2020. During that year we noticed an alarming increase in cases of nosocomial Candidemia: 26 versus an average of 2.8 cases per year over the previous 5 years. 19 of the 26 episodes (73%) of Candidemia occurred in patients who were admitted with acute COVID-19 infection. Recent reports suggest that hospitalized patients with COVID-19 are at increased risk for developing Candidemia, however their clinical characteristics, risk factors and outcomes have not been well described. We evaluated the risk factors and mortality of hospitalized COVID-19 patients with Candidemia. Methods We performed a retrospective chart review of 19 patients with Candidemia and confirmed COVID-19 infection at a 292-bed community teaching hospital in Chicago, Illinois from January through December 2020. We report a descriptive analysis of the demographic characteristics, comorbidities, complications, and outcomes of these patients. Results The average age of our study population was 65 years; 68% were male. The average hospital length of stay (LOS) was 34 days. The mean time from admission to the development of Candidemia was 16 days. Associated co-morbidities included cardiovascular diseases (CVD) in 79%, diabetes mellitus (DM), in 68%, and obesity in 50%. Underlying kidney disease was present in 10%. Treatments for COVID-19 included convalescent plasma (53%), remdesivir (53%), steroids (52%) and tocilizumab (19%). All patients were managed in the intensive care unit (ICU) and 95% required multiple central line (CL) placements. Most of the patients (58%) required hemodialysis (HD); all patients were treated with multiple antibiotics. The average LOS in the ICU was 25 days. Despite anti-fungal treatment, 68% expired. The 28-day mortality was 50%. Conclusion The occurrence of Candidemia in our hospitalized patients with acute COVID-19 infection was associated with a history of CVD, DM, obesity, prolonged hospital LOS, requirement for multiple CL, HD, treatment with multiple antibiotics and a long stay in the ICU. The mortality of COVID-19 patients with Candidemia is high. The development of strategies to mitigate the occurrence of nosocomial Candidemia in this population of patients is urgently needed. Disclosures All Authors: No reported disclosures

Candidiasis as Secondary Infection in Post COVID-19: A New Problem?

Introduction: Severe Acute Respiratory Syndrome (SARS-CoV-2) can develop into post COVID-19 with one of its main attentions being secondary infection. Candidiasis as fungal pneumonia is one of secondary infection in post COVID-19. It is hard to diagnose and has high mortality. We present a case of candidiasis as fungal pneumonia in post COVID-19 patient.Case: A 47-year-old woman came to the emergency room with major complaints of dyspnoea and jaundice since her second day at home after being discharged from having COVID-19. She previously finished her COVID treatment and tested negative 2 times. She had severe sepsis and her sputum culture was positive for non-albicans Candida. She received anti-fungal treatment and her condition was getting better and her chest X-ray showed less infiltrates than before.Discussion: Fungal respiratory infections generate concern in the expanding population of immunosuppressed patients like COVID-19 patient. The mortality from COVID-19 associated candidiasis is high (19-40%) as one of fungal infection. Marked immune dysregulation in COVID-19 makes system immune becomes impaired, it also harms lung epithelium. In this patient, diagnosis and treatment were challenging.Conclusion: Post COVID-19 is a condition that should be given more attention, especially when it develops secondary infection. Candidiasis as fungal pneumonia is hard to diagnose and can quickly become severe sepsis and has high mortality. Health practitioners should recognize it as soon as possible and give the best treatment for the patient.

An Overview of an Invasive Fungal Infection In Covid-19: Mucormycosis

Mucormycosis is an invasive fungal infection of zygomycetes class, comprised the orders of entomophtherales and mucorales which is common infection in immuno compromised patients, especially in stem cell transplantation, hematological malignancy and diabetes mellitus. It is the third invasive fungal infection after aspergillosis and candidiasis both strain belong the class of zygomycetes. Mucormycosis generally transmitted in humans by the inoculation and inhalation of spores in mucous membrane as well as skin. After the deadly outbreak of corona virus, this infection has taken a different form in those patients who suffer from the covid-19 which is categorized as a post covid-19 disease. Aim of this review to highlight the recent awareness about invasive fungal treatment.