Lack of 1-3-B-D-glucan detection in adults with bacteraemia.

Bacteraemia was reported to be associated with false-positive 1→3-ß-D-glucan (BG) assay results. We thus prospectively assessed the reactivity of the BG (Fungitell) in samples of 21 adults with bacteraemia: . BG was negative in all and is s therefore an unlikely cause of false positive BG in adults.

Postpandemic Evaluation of the Eco-Efficiency of Personal Protective Equipment Against COVID-19 in Emergency Departments: Proposal for a Mixed Methods Study.

BACKGROUND: The COVID-19 pandemic has had a profound impact on emergency department (ED) care in Canada and around the world. To prevent transmission of COVID-19, personal protective equipment (PPE) was required for all ED care providers in contact with suspected cases. With mass vaccination and improvements in several infection prevention components, our hypothesis is that the risks of transmission of COVID-19 will be significantly reduced and that current PPE use will have economic and ecological consequences that exceed its anticipated benefits. Evidence is needed to evaluate PPE use so that recommendations can ensure the clinical, economic, and environmental efficiency (ie, eco-efficiency) of its use. OBJECTIVE: To support the development of recommendations for the eco-efficient use of PPE, our research objectives are to (1) estimate the clinical effectiveness (reduced transmission, hospitalizations, mortality, and work absenteeism) of PPE against COVID-19 for health care workers; (2) estimate the financial cost of using PPE in the ED for the management of suspected or confirmed COVID-19 patients; and (3) estimate the ecological footprint of PPE use against COVID-19 in the ED. METHODS: We will conduct a mixed method study to evaluate the eco-efficiency of PPE use in the 5 EDs of the CHU de Québec-Université Laval (Québec, Canada). To achieve our goals, the project will include four phases: systematic review of the literature to assess the clinical effectiveness of PPE (objective 1; phase 1); cost estimation of PPE use in the ED using a time-driven activity-based costing method (objective 2; phase 2); ecological footprint estimation of PPE use using a life cycle assessment approach (objective 3; phase 3); and cost-consequence analysis and focus groups (integration of objectives 1 to 3; phase 4). RESULTS: The first 3 phases have started. The results of these phases will be available in 2023. Phase 4 will begin in 2023 and results will be available in 2024. CONCLUSIONS: While the benefits of PPE use are likely to diminish as health care workers' immunity increases, it is important to assess its economic and ecological impacts to develop recommendations to guide its eco-efficient use. TRIAL REGISTRATION: PROSPERO CRD42022302598; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=302598. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/50682.

[Chronic granulomatous disease: pathogenesis and therapy of associated fungal infections]. / Infections fongiques et granulomatose septique chronique - De la physiopathologie aux nouvelles perspectives thérapeutiques.

Chronic granulomatous disease is a genetic disorder responsible for a defect in the NADPH oxidase of phagocytic cells. It impairs the oxidative burst necessary to the intracellular inactivation of microorganisms and predisposes to an increased risk of infections by various microorganisms, including fungi like Aspergillus spp. and other less frequently encountered or emerging fungal species. Here we review the genetic basis, pathogenesis and clinical presentation associated with fungal infections in chronic granulomatous disease as well as the current prophylaxis and newly available therapies.

Evidence that a secondary metabolic biosynthetic gene cluster has grown by gene relocation during evolution of the filamentous fungus Fusarium.

Trichothecenes are terpene-derived secondary metabolites produced by multiple genera of filamentous fungi, including many plant pathogenic species of Fusarium. These metabolites are of interest because they are toxic to animals and plants and can contribute to pathogenesis of Fusarium on some crop species. Fusarium graminearum and F. sporotrichioides have trichothecene biosynthetic genes (TRI) at three loci: a 12-gene TRI cluster and two smaller TRI loci that consist of one or two genes. Here, comparisons of additional Fusarium species have provided evidence that TRI loci have a complex evolutionary history that has included loss, non-functionalization and rearrangement of genes as well as trans-species polymorphism. The results also indicate that the TRI cluster has expanded in some species by relocation of two genes into it from the smaller loci. Thus, evolutionary forces have driven consolidation of TRI genes into fewer loci in some fusaria but have maintained three distinct TRI loci in others.

Structure-activity relationships of trichothecene toxins in an Arabidopsis thaliana leaf assay.

Many Fusarium species produce trichothecenes, sesquiterpene epoxides that differ in patterns of oxygenation and esterification at carbon positions C-3, C-4, C-7, C-8, and C-15. For the first comprehensive and quantitative comparison of the effects of oxygenation and esterification on trichothecene phytotoxicity, we tested 24 precursors, intermediates, and end products of the trichothecene biosynthetic pathway in an Arabidopsis thaliana detached leaf assay. At 100 microM, the highest concentration tested, only the trichothecene precursor trichodiene was nontoxic. Among trichothecenes, toxicity varied more than 200-fold. Oxygenation at C-4, C-8, C-7/8, or C-15 was, on average, as likely to decrease as to increase toxicity. Esterification at C-4, C-8, or C-15 generally increased toxicity. Esterification at C-3 increased toxicity in one case and decreased toxicity in three of eight cases tested. Thus, the increase in structural complexity along the trichothecene biosynthetic pathway in Fusarium is not necessarily associated with an increase in phytotoxicity.

Maize ear rot and moniliformin contamination by cryptic species of Fusarium subglutinans.

Fusarium subglutinans causes maize ear rot and contaminates grain with the mycotoxin moniliformin. Previous DNA sequence analysis divided F. subglutinans from maize into two cryptic species, designated groups 1 and 2. Here, it was determined whether the two groups differ in the agriculturally important traits of virulence on maize and moniliformin production in planta. Thirty-seven strains from U.S. maize were assigned to groups 1 and 2 by DNA sequence analysis. In field tests, all strains were highly virulent on maize inbred B73 and four maize hybrids. In planta, 82% of group 1 strains and 25% of group 2 strains produced high levels (100-1500 microg/g) of moniliformin. All group 2 strains from more northern states produced little or no moniliformin (0-5 microg/g). These data indicate that moniliformin production is highly variable in F. subglutinans from U.S. maize and that production may not be required for the fungus to cause maize ear rot.

Fumonisin production in the maize pathogen Fusarium verticillioides: genetic basis of naturally occurring chemical variation.

Fumonisins are polyketide-derived mycotoxins produced by the maize pathogen Fusarium verticillioides. Previous analyses identified naturally occurring variants of the fungus that are deficient in fumonisin C-10 hydroxylation or that do not produce any fumonisins. In the current study, gene deletion and genetic complementation analyses localized the C-10 hydroxylation deficiency to a cytochrome P450 monooxygenase gene in the fumonisin biosynthetic gene (FUM) cluster. Sequence analysis indicated that the hydroxylation deficiency resulted from a single nucleotide insertion that caused a frame shift in the coding region of the gene. Genetic complementation localized the fumonisin-nonproduction phenotype to the polyketide synthase gene in the FUM cluster, and sequence analysis indicated that the nonproduction phenotype resulted from a nucleotide substitution, which introduced a premature stop codon in the coding region. These results provide the first direct evidence that altered fumonisin production phenotypes of naturally occurring F. verticillioides variants can result from single point mutations in the FUM cluster.

Gibberella from A (venaceae) to Z (eae).

Gibberella species are destructive plant pathogens, although many are more familiar under their Fusarium anamorph names. The recent synthesis of phylogenetic, biological, and morphological species approaches has revitalized taxonomy of a genus that was first described almost 200 years ago. Twelve sexual species of Gibberella of agricultural importance were selected for this review to represent phylogenetic, biological, and chemical diversity of the genus. Even closely related Gibberella species can differ in reproductive mode, geographic and host distribution, plant pathogenesis, and production of toxins and other biologically active metabolites. Gibberella species have proven amenable to meiotic and molecular genetic analysis; A complete genome sequence of G. zeae should soon be available. Combining gene disruption strategies with new genomics technologies for expression profiling should help plant pathologists to understand the pathological and evolutionary significance of biological and chemical diversity in Gibberella and to identify novel strategies for disease control.

Identification and heritability of fumonisin insensitivity in Zea mays.

Landraces of maize (Zea mays ssp. mays) and its wild teosinte relatives (Zea mays spp. parviglumis and mexicana) were surveyed for sensitivity to fumonisin B(1), a phytotoxin produced by the maize pathogen Gibberella moniliformis. Only two of 42 Z. mays samples were highly insensitive to FB(1) (ED(50) = ca. 200 microM). The teosintes and 76% of the maize landraces were moderately or highly sensitive to FB(1) (ED(50) < or = 30 microM), which indicates that FB(1) sensitivity is likely to be an ancestral trait in Z. mays. F(1) generations derived from crosses between FB(1)-sensitive maize inbred B73 and insensitive landraces were significantly less sensitive than B73. Thus, our data indicate that FB(1)-insensitivity is a relatively rare but heritable trait in maize. We also report the sensitivity of maize to other Gibberella toxins - beauvericin, diacetoxyscirpenol, and moniliformin.

Patterns of trichothecene production, genetic variability, and virulence to wheat of Fusarium graminearum from smallholder farms in Nepal.

Fusarium graminearum causes wheat head blight and contaminates grain with the trichothecenes 4-deoxynivalenol and nivalenol. Sequence analysis of trichothecene genes indicates that nivalenol production is the ancestral trait; however, deoxynivalenol producers occur worldwide and predominate in North and South America and in Europe. Analysis of a large field population (>500 strains) from Nepal identified three groups that were both genetically distinct and polymorphic for trichothecene production: SCAR1 comprising 95% deoxynivalenol producers, SCAR2 comprising 94% nivalenol producers, and SCAR3/5 comprising 34% deoxynivalenol producers/63% nivalenol producers. The ability to cause wheat head blight differed between SCAR groups and trichothecene chemotypes: deoxynivalenol producers were more virulent than nivalenol producers across all three SCAR groups and within the SCAR3/5 genetic background. These data support the hypothesis that production of deoxynivalenol rather than nivalenol confers a selective advantage to this important wheat pathogen.

Cryptic speciation in Fusarium subglutinans.

Fusarium isolates that form part of the Gibberella fujikuroi species complex have been classified using either a morphological, biological, or phylogenetic species concept. Problems with the taxonomy of Fusarium species in this complex are mostly experienced when the morphological and biological species concepts are applied. The most consistent identifications are obtained with the phylogenetic species concept. Results from recent studies have presented an example of discordance between the biological and phylogenetic species concepts, where a group of F. subglutinans sensu stricto isolates, i.e., isolates belonging to mating population E of the G. fujikuroi complex, could be sub-divided into more than one phylogenetic lineage. The aim of this study was to determine whether this sub-division represented species divergence or intraspecific diversity in F. subglutinans. For this purpose, we included 29 F. subglutinans isolates belonging to the E-mating population that were collected from either maize or teosinte, from a wide geographic range. DNA sequence data for six nuclear regions in each of these isolates were obtained and used in phylogenetic concordance analyses. These analyses revealed the presence of two major groups representing cryptic species in F. subglutinans. These cryptic species were further sub-divided into a number of smaller groups that appear to be reproductively isolated in nature. This suggests not only that the existing F. subglutinans populations are in the process of divergence, but also that each of the resulting lineages are undergoing separation into distinct taxa. These divergences did not appear to be linked to geographic origin, host, or phenotypic characters such as morphology.

Distribution of Fumonisins in Maize Ears Infected with Strains of Fusarium moniliforme that Differ in Fumonisin Production.

Strains of Fusarium moniliforme (Gibberella fujikuroi mating population A) that differ in fu-monisin production in vitro were previously identified in a Kansas field population. One strain that produced high levels of fumonisins and two strains that produced very low levels of fu-monisins were applied to maize kernels at planting at the Rocky Ford Farm near Manhattan, Kansas. The distribution of fumonisins in symptomatic and symptomless kernels from individual harvested ears was determined by high performance liquid chromatography, and the distribution of the three applied strains in the kernels was determined by vegetative compatibility group analysis. Both symptomatic and symptomless kernels were extensively colonized with F. moniliforme, but the highest levels of fumonisins were in the symptomatic kernels. All three applied strains were recovered from kernels in 1993, and two of them were recovered from kernels in 1994. However, a high frequency of ear and kernel infection with a strain that produced little fumonisin in vitro did not consistently decrease the level of fumonisins. The frequency of infection with fumonisin low-producing strains may have been too low for competitive exclusion of naturally occurring fumonisin high-producing strains. Also, strains that are low-fumonisin producers under laboratory conditions may be high producers in the field.

United States Department of Agriculture-Agricultural Research Service research on pre-harvest prevention of mycotoxins and mycotoxigenic fungi in US crops.

Mycotoxins (ie toxins produced by molds) are fungal metabolites that can contaminate foods and feeds and cause toxic effects in higher organisms that consume the contaminated commodities. Therefore, mycotoxin contamination of foods and feeds results is a serious food safety issue and affects the competitiveness of US agriculture in both domestic and export markets. This article highlights research accomplished by Agricultural Research Service (ARS) laboratories on control of pre-harvest toxin contamination by using biocontrol, host-plant resistance enhancement and integrated management systems. Emphasis is placed on the most economically relevant mycotoxins, namely aflatoxins produced by Aspergillus flavus, Link, trichothecenes produced by various Fusarium spp and fumonisins produced by F verticillioides. Significant inroads have been made in establishing various control strategies such as development of atoxigenic biocontrol fungi that can outcompete their closely related, toxigenic cousins in field environments, thus reducing levels of mycotoxins in the crops. Potential biochemical and genetic resistance markers have been identified in crops, particularly in corn, which are being utilized as selectable markers in breeding for resistance to aflatoxin contamination. Prototypes of genetically engineered crops have been developed which: (1) contain genes for resistance to the phytotoxic effects of certain trichothecenes, thereby helping reduce fungal virulence, or (2) contain genes encoding fungal growth inhibitors for reducing fungal infection. Gene clusters housing the genes governing formation of trichothecenes, fumonisins and aflatoxins have been elucidated and are being targeted in strategies to interrupt the biosynthesis of these mycotoxins. Ultimately, a combination of strategies using biocompetitive fungi and enhancement of host-plant resistance may be needed to adequately prevent mycotoxin contamination in the field. To achieve this, plants may be developed that resist fungal infection and/or reduce the toxic effects of the mycotoxins themselves, or interrupt mycotoxin biosynthesis. This research effort could potentially save affected agricultural industries hundreds of millions of dollars during years of serious mycotoxin outbreaks.

Gemella sanguinis endocarditis with c-ANCA/anti-PR-3-associated immune complex necrotizing glomerulonephritis with a 'full-house' pattern on immunofluorescence microscopy.

A 67-year-old man was evaluated for haematuria, with a rising creatinine level from 88 to 906 µmol/L and positive c-anti-neutrophil cytoplasm antibody (ANCA)/anti-proteinase 3 (anti-PR3). A kidney biopsy revealed necrotizing glomerulonephritis with a 'full-house' pattern on immunofluorescence microscopy. Echocardiography and blood cultures growing Gemella sanguinis diagnosed endocarditis. Dialysis was required for a month. Three months later, following valve replacement, glucocorticoids and 2 months of antibiotic therapy, the creatinine level decreased to 62 µmol/L and c-ANCA/anti-PR3 disappeared. This first case of c-ANCA/anti-PR3 positive glomerulonephritis with a 'full-house' immunofluorescence pattern due to bacterial endocarditis underlines the importance of ruling out infection with ANCA positivity or kidney biopsy suggestive of lupus nephritis.

Genetic diversity and trichothecene chemotypes of the Fusarium graminearum clade isolated from maize in Nepal and identification of a putative new lineage.

On smallholder farms in the foothills of the Himalayan Mountains in Nepal, fungi of the Fusarium graminearum clade cause Gibberella ear rot of maize and contamination with the 8-ketotrichothecenes nivalenol and deoxynivalenol. Previous DNA marker analyses of the F. graminearum clade from maize in Nepal found a high level of genetic diversity but were limited in detail or scope. The present study incorporated a collection of 251 field strains from a wide geographic distribution in Nepal and utilized sequencing of the MAT1-1-3 gene of the mating type locus to determine the number and frequency of lineages and species of the F. graminearum clade. The frequency of nivalenol and deoxynivalenol chemotypes was determined by chemical analysis and by TRI13 deletion-marker analysis. We found that Gibberella ear rot of maize in Nepal is associated with a complex of species of the F. graminearum clade - mainly Fusarium asiaticum and Fusarium meridionale, but also Fusarium boothii and a putative new lineage, which we have designated the 'Nepal lineage'. Fusarium graminearum sensu stricto, which dominates in maize elsewhere in Asia and worldwide, was not detected in Nepal. Although nivalenol production has been associated experimentally with lower virulence in maize ear rot and wheat head blight, this collection of the F. graminearum clade from maize in Nepal is dominated (4:1) by nivalenol producers, suggesting that traits other than crop plant pathogenesis affect population structure in this complex agroecosystem.

From yellow rain to green wheat: 25 years of trichothecene biosynthesis research.

Trichothecene biosynthesis research at the U.S. Department of Agriculture in Peoria, IL, began in 1984 in response to concerns about the use of trichothecenes in biological warfare, but continued as a long-term research program on the intractable problem of trichothecene contamination of human foods and animal feeds. Over 25 years, the trichothecene biosynthesis research group integrated natural product chemistry with fungal genetics and plant pathology in the laboratory and in the field to understand how and why Fusarium species make these complex and highly toxic metabolites. This interdisciplinary research placed trichothecenes in the unique class of fungal metabolites that not only cause mycotoxicoses in animals but also are virulence factors in plant disease.

Natural product chemistry meets genetics: when is a genotype a chemotype?

The chemotype of a microbial or plant species has traditionally been defined as its profile of natural products, and the genotype has been defined as its genetic constitution or DNA sequence. The purpose of this perspective is to discuss applications of DNA genotyping, particularly by polymerase chain reaction (PCR)-amplification methods, to predicting natural product chemotypes of fungi and plants of importance in food and agriculture. Development of PCR genotyping for predicting chemotypes will require collaboration between molecular biologists and natural product chemists, as well as community standards for reporting data. PCR genotyping should be validated by chemical analysis of individuals that represent the allelic diversity of the target gene in the population. To avoid misinterpretation, it is critical to differentiate data obtained by genotyping from data obtained by chemical analysis. The obvious and appropriate solution is to retain the established meanings of genotype and chemotype, both of which have been in use for half a century in the fields of genetics and natural product chemistry.

Gibberella ear rot of maize (Zea mays) in Nepal: distribution of the mycotoxins nivalenol and deoxynivalenol in naturally and experimentally infected maize.

The fungus Fusarium graminearum (sexual stage Gibberella zeae) causes ear rot of maize (Zea mays) and contamination with the 8-ketotrichothecenes nivalenol (1) or 4-deoxynivalenol (2), depending on diversity of the fungal population for the 4-oxygenase gene (TRI13). To determine the importance of 1 and 2 in maize ear rot, a survey of naturally contaminated maize in Nepal was combined with experiments in the field and in a plant growth room. In the survey, 1 contamination was 4-fold more frequent than 2 contamination and 1-producers (TRI13) were isolated more than twice as frequently as 2-producers (Psi TRI13). In maize ear rot experiments, genetically diverse 1-producers and 2-producers caused ear rot and trichothecene contamination. Among strains with the same genetic background, however, 1-producers caused less ear rot and trichothecene contamination than did 2-producers. The high frequency of 1 contamination and the high virulence of many 1-producers are of concern because maize is a staple food of rural populations in Nepal and because 1 has proven to be more toxic than 2 to animals.