Eumycetoma causative agents: A systematic review to inform the World Health Organization priority list of fungal pathogens.

The World Health Organization, in response to the growing burden of fungal disease, established a process to develop a fungal priority pathogens list. This systematic review aimed to evaluate the epidemiology and impact of eumycetoma. PubMed and Web of Science were searched to identify studies published between 1 January 2011 and 19 February 2021. Studies reporting on mortality, inpatient care, complications and sequelae, antifungal susceptibility, risk factors, preventability, annual incidence, global distribution, and emergence during the study time frames were selected. Overall, 14 studies were eligible for inclusion. Morbidity was frequent with moderate to severe impairment of quality of life in 60.3%, amputation in up to 38.5%, and recurrent or long-term disease in 31.8%-73.5% of patients. Potential risk factors included male gender (56.6%-79.6%), younger age (11-30 years; 64%), and farming occupation (62.1%-69.7%). Mycetoma was predominantly reported in Sudan, particularly in central Sudan (37%-76.6% of cases). An annual incidence of 0.1/100 000 persons and 0.32/100 000 persons/decade was reported in the Philippines and Uganda, respectively. In Uganda, a decline in incidence from 3.37 to 0.32/100 000 persons between two consecutive 10-year periods (2000-2009 and 2010-2019) was detected. A community-based, multi-pronged prevention programme was associated with a reduction in amputation rates from 62.8% to 11.9%. With the pre-specified criteria, no studies of antifungal drug susceptibility, mortality, and hospital lengths of stay were identified. Future research should include larger cohort studies, greater drug susceptibility testing, and global surveillance to develop evidence-based treatment guidelines and to determine more accurately the incidence and trends over time.

Candida auris-a systematic review to inform the world health organization fungal priority pathogens list.

The World Health Organization (WHO) in 2022 developed a fungal priority pathogen list. Candida auris was ultimately ranked as a critical priority pathogen. PubMed and Web of Science were used to find studies published from 1 January 2011 to 18 February 2021, reporting on predefined criteria including: mortality, morbidity (i.e., hospitalization and disability), drug resistance, preventability, yearly incidence, and distribution/emergence. Thirty-seven studies were included in the final analysis. The overall and 30-day mortality rates associated with C. auris candidaemia ranged from 29% to 62% and 23% to 67%, respectively. The median length of hospital stay was 46-68 days, ranging up to 140 days. Late-onset complications of C. auris candidaemia included metastatic septic complications. Resistance rates to fluconazole were as high as 87%-100%. Susceptibility to isavuconazole, itraconazole, and posaconazole varied with MIC90 values of 0.06-1.0 mg/l. Resistance rates to voriconazole ranged widely from 28% to 98%. Resistance rates ranged between 8% and 35% for amphotericin B and 0%-8% for echinocandins. Over the last ten years, outbreaks due to C. auris have been reported in in all WHO regions. Given the outbreak potential of C. auris, the emergence and spread of MDR strains, and the challenges associated with its identification, and eradication of its environmental sources in healthcare settings, prevention and control measures based on the identified risk factors should be evaluated for their effectiveness and feasibility. Global surveillance studies could better inform the incidence rates and distribution patterns to evaluate the global burden of C. auris infections.

Candida tropicalis-A systematic review to inform the World Health Organization of a fungal priority pathogens list.

In response to the growing global burden of fungal infections with uncertain impact, the World Health Organization (WHO) established an Expert Group to identify priority fungal pathogens and establish the WHO Fungal Priority Pathogens List for future research. This systematic review aimed to evaluate the features and global impact of invasive candidiasis caused by Candida tropicalis. PubMed and Web of Science were searched for studies reporting on criteria of mortality, morbidity (defined as hospitalization and disability), drug resistance, preventability, yearly incidence, diagnostics, treatability, and distribution/emergence from 2011 to 2021. Thirty studies, encompassing 436 patients from 25 countries were included in the analysis. All-cause mortality due to invasive C. tropicalis infections was 55%-60%. Resistance rates to fluconazole, itraconazole, voriconazole and posaconazole up to 40%-80% were observed but C. tropicalis isolates showed low resistance rates to the echinocandins (0%-1%), amphotericin B (0%), and flucytosine (0%-4%). Leukaemia (odds ratio (OR) = 4.77) and chronic lung disease (OR = 2.62) were identified as risk factors for invasive infections. Incidence rates highlight the geographic variability and provide valuable context for understanding the global burden of C. tropicalis infections. C. tropicalis candidiasis is associated with high mortality rates and high rates of resistance to triazoles. To address this emerging threat, concerted efforts are needed to develop novel antifungal agents and therapeutic approaches tailored to C. tropicalis infections. Global surveillance studies could better inform the annual incidence rates, distribution and trends and allow informed evaluation of the global impact of C. tropicalis infections.

Fusarium species,Scedosporium species, and Lomentospora prolificans: A systematic review to inform the World Health Organization priority list of fungal pathogens.

Recognizing the growing global burden of fungal infections, the World Health Organization established a process to develop a priority list of fungal pathogens (FPPL). In this systematic review, we aimed to evaluate the epidemiology and impact of infections caused by Fusarium spp., Scedosporium spp., and Lomentospora prolificans to inform the first FPPL. PubMed and Web of Sciences databases were searched to identify studies published between January 1, 2011 and February 23, 2021, reporting on mortality, complications and sequelae, antifungal susceptibility, preventability, annual incidence, and trends. Overall, 20, 11, and 9 articles were included for Fusarium spp., Scedosporium spp., and L. prolificans, respectively. Mortality rates were high in those with invasive fusariosis, scedosporiosis, and lomentosporiosis (42.9%-66.7%, 42.4%-46.9%, and 50.0%-71.4%, respectively). Antifungal susceptibility data, based on small isolate numbers, showed high minimum inhibitory concentrations (MIC)/minimum effective concentrations for most currently available antifungal agents. The median/mode MIC for itraconazole and isavuconazole were ≥16 mg/l for all three pathogens. Based on limited data, these fungi are emerging. Invasive fusariosis increased from 0.08 cases/100 000 admissions to 0.22 cases/100 000 admissions over the time periods of 2000-2009 and 2010-2015, respectively, and in lung transplant recipients, Scedosporium spp. and L. prolificans were only detected from 2014 onwards. Global surveillance to better delineate antifungal susceptibility, risk factors, sequelae, and outcomes is required.

The role of bacterial vaccines in the fight against antimicrobial resistance: an analysis of the preclinical and clinical development pipeline.

Vaccines can be highly effective tools in combating antimicrobial resistance as they reduce infections caused by antibiotic-resistant bacteria and antibiotic consumption associated with disease. This Review looks at vaccine candidates that are in development against pathogens on the 2017 WHO bacterial priority pathogen list, in addition to Clostridioides difficile and Mycobacterium tuberculosis. There were 94 active preclinical vaccine candidates and 61 active development vaccine candidates. We classified the included pathogens into the following four groups: Group A consists of pathogens for which vaccines already exist-ie, Salmonella enterica serotype Typhi, Streptococcus pneumoniae, Haemophilus influenzae type b, and M tuberculosis. Group B consists of pathogens with vaccines in advanced clinical development-ie, extra-intestinal pathogenic Escherichia coli, Salmonella enterica serotype Paratyphi A, Neisseria gonorrhoeae, and C difficile. Group C consists of pathogens with vaccines in early phases of clinical development-ie, enterotoxigenic E coli, Klebsiella pneumoniae, non-typhoidal Salmonella, Shigella spp, and Campylobacter spp. Finally, group D includes pathogens with either no candidates in clinical development or low development feasibility-ie, Pseudomonas aeruginosa, Acinetobacter baumannii, Staphylococcus aureus, Helicobacter pylori, Enterococcus faecium, and Enterobacter spp. Vaccines are already important tools in reducing antimicrobial resistance and future development will provide further opportunities to optimise the use of vaccines against resistance.

First Pediatric Pyeloplasty Using the Senhance® Robotic System-A Case Report.

A pediatric robotic pyeloplasty has been performed with the Senhance® robotic system for the first time in January 2021 on a 1.5-year-old girl with symptomatic ureteropelvic junction stenosis. A Senhance® robotic system (Asensus Surgical® Inc., Durham, NC, USA) with three arms and 5 mm instruments was used, providing infrared eye tracking of the 5 mm camera and haptic feedback for the surgeon, facilitating suturing of the anastomosis and double-J stent insertion. The robotic surgery lasted 4.5 h, was uneventful and successful, without recurrence of the ureteropelvic junction obstruction after six months, and with normal development of the patient's growth and organ function. The use of the robotic system was shown to be safe and feasible; long term follow-up will be conducted subsequently in pediatric surgery.

Analysis of the Clinical Pipeline of Treatments for Drug-Resistant Bacterial Infections: Despite Progress, More Action Is Needed.

There is an urgent global need for new strategies and drugs to control and treat multidrug-resistant bacterial infections. In 2017, the World Health Organization (WHO) released a list of 12 antibiotic-resistant priority pathogens and began to critically analyze the antibacterial clinical pipeline. This review analyzes "traditional" and "nontraditional" antibacterial agents and modulators in clinical development current on 30 June 2021 with activity against the WHO priority pathogens mycobacteria and Clostridioides difficile. Since 2017, 12 new antibacterial drugs have been approved globally, but only vaborbactam belongs to a new antibacterial class. Also innovative is the cephalosporin derivative cefiderocol, which incorporates an iron-chelating siderophore that facilitates Gram-negative bacteria cell entry. Overall, there were 76 antibacterial agents in clinical development (45 traditional and 31 nontraditional), with 28 in phase 1, 32 in phase 2, 12 in phase 3, and 4 under regulatory evaluation. Forty-one out of 76 (54%) targeted WHO priority pathogens, 16 (21%) were against mycobacteria, 15 (20%) were against C. difficile, and 4 (5%) were nontraditional agents with broad-spectrum effects. Nineteen of the 76 antibacterial agents have new pharmacophores, and 4 of these have new modes of actions not previously exploited by marketed antibacterial drugs. Despite there being 76 antibacterial clinical candidates, this analysis indicated that there were still relatively few clinically differentiated antibacterial agents in late-stage clinical development, especially against critical-priority pathogens. We believe that future antibacterial research and development (R&D) should focus on the development of innovative and clinically differentiated candidates that have clear and feasible progression pathways to the market.

Plant apocarotenoid metabolism utilizes defense mechanisms against reactive carbonyl species and xenobiotics.

Carotenoid levels in plant tissues depend on the relative rates of synthesis and degradation of the molecules in the pathway. While plant carotenoid biosynthesis has been extensively characterized, research on carotenoid degradation and catabolism into apocarotenoids is a relatively novel field. To identify apocarotenoid metabolic processes, we characterized the transcriptome of transgenic Arabidopsis (Arabidopsis thaliana) roots accumulating high levels of ß-carotene and, consequently, ß-apocarotenoids. Transcriptome analysis revealed feedback regulation on carotenogenic gene transcripts suitable for reducing ß-carotene levels, suggesting involvement of specific apocarotenoid signaling molecules originating directly from ß-carotene degradation or after secondary enzymatic derivatizations. Enzymes implicated in apocarotenoid modification reactions overlapped with detoxification enzymes of xenobiotics and reactive carbonyl species (RCS), while metabolite analysis excluded lipid stress response, a potential secondary effect of carotenoid accumulation. In agreement with structural similarities between RCS and ß-apocarotenoids, RCS detoxification enzymes also converted apocarotenoids derived from ß-carotene and from xanthophylls into apocarotenols and apocarotenoic acids in vitro. Moreover, glycosylation and glutathionylation-related processes and translocators were induced. In view of similarities to mechanisms found in crocin biosynthesis and cellular deposition in saffron (Crocus sativus), our data suggest apocarotenoid metabolization, derivatization and compartmentalization as key processes in (apo)carotenoid metabolism in plants.

Reimbursement models to tackle market failures for antimicrobials: Approaches taken in France, Germany, Sweden, the United Kingdom, and the United States.

INTRODUCTION: The pipeline of new antibacterials remains limited. Reasons include low research investments, limited commercial prospects, and scientific challenges. To complement existing initiatives such as research grants, governments are exploring policy options for providing new market incentives to drug developers. MATERIALS AND METHODS: Reimbursement interventions for antibacterials in France, Germany, Sweden, US, and UK were reviewed and analysed by the authors. RESULTS: In France, Germany, and the US, implemented interventions centre on providing exceptions in cost-containment mechanisms to allow higher prices for certain antibacterials. In the US, also, certain antibacterials are granted additional years of protection from generic competition (exclusivity) and faster regulatory review. The UK is piloting a model that will negotiate contracts with manufacturers to pay a fixed annual fee for ongoing supply of as many units as needed. Sweden is piloting a model that will offer manufacturers of selected antibacterials contracts that would guarantee a minimum annual revenue. A similar model of guaranteed minimal annual revenues is under consideration in the US (PASTEUR Act). CONCLUSIONS: The UK and Sweden are piloting entirely novel procurement and reimbursement models. Existing interventions in the US, France, and Germany represent important, but relatively minor interventions. More countries should explore the use of novel models and international coordination will be important for 'pull' incentives to be effective. If adopted, the PASTEUR legislation in the US would constitute a significant 'pull' incentive.

A novel pre-clinical antibacterial pipeline database.

The clinical pipeline continues to be insufficient to contain antimicrobial resistance, and further investment and research is needed to ensure that a robust pipeline is built to treat the WHO priority pathogens list of antibiotic-resistant bacteria. To shed light further upstream on the preclinical pipeline the WHO has undertaken a review of the antibacterial preclinical pipeline and published the data of all identified projects in a publicly accessible database. The database captures 252 unique antibacterial agents in preclinical development being developed by 145 individual institutions, of which the majority are smaller biotech companies and academic institutions. There is a higher degree of innovation in the preclinical pipeline with a significant number of non-traditional approaches being pursued. For even a fraction of these projects to reach clinical development or the market, there is a need to shift the market dynamics for new antibacterials through the identification of new solutions beyond push and pull incentives.

Molecular characterization and safety assessment of biofortified provitamin A rice.

Part of the studies involved in safety assessment of genetically engineered crops includes characterizing the organization, integrity, and stability of the inserted DNA and evaluating the potential allergenicity and toxicity of newly-expressed proteins. Molecular characterization of the introduced DNA in provitamin A biofortified rice event GR2E confirmed insertion of a single copy of the transfer-DNA in the genome and its inheritance as a single locus. Nucleotide sequencing of the inserted DNA confirmed it was introduced without modifications. The phytoene synthase, and carotene desaturase proteins did not display sequence similarity with allergens or toxins. Both proteins were rapidly digested in simulated gastric fluid and their enzymatic activity was inhibited upon heat treatment. Acute oral toxicity testing of the protein in mice demonstrated lack of adverse effects. These evidences substantiated the lack of any identifiable hazards for both proteins and in combination with other existing comparative analyses provided assurance that food derived from this rice is safe. This conclusion is in line with those of the regulatory agencies of US Food and Drug Administration, Health Canada and Food Standard Australia and New Zealand.

Electron transport pathways in isolated chromoplasts from Narcissus pseudonarcissus L.

During daffodil flower development, chloroplasts differentiate into photosynthetically inactive chromoplasts having lost functional photosynthetic reaction centers. Chromoplasts exhibit a respiratory activity reducing oxygen to water and generating ATP. Immunoblots revealed the presence of the plastid terminal oxidase (PTOX), the NAD(P)H dehydrogenase (NDH) complex, the cytochrome b6 f complex, ATP synthase and several isoforms of ferredoxin-NADP+ oxidoreductase (FNR), and ferredoxin (Fd). Fluorescence spectroscopy allowed the detection of chlorophyll a in the cytochrome b6 f complex. Here we characterize the electron transport pathway of chromorespiration by using specific inhibitors for the NDH complex, the cytochrome b6 f complex, FNR and redox-inactive Fd in which the iron was replaced by gallium. Our data suggest an electron flow via two separate pathways, both reducing plastoquinone (PQ) and using PTOX as oxidase. The first oxidizes NADPH via FNR, Fd and cytochrome bh of the cytochrome b6 f complex, and does not result in the pumping of protons across the membrane. In the second, electron transport takes place via the NDH complex using both NADH and NADPH as electron donor. FNR and Fd are not involved in this pathway. The NDH complex is responsible for the generation of the proton gradient. We propose a model for chromorespiration that may also be relevant for the understanding of chlororespiration and for the characterization of the electron input from Fd to the cytochrome b6 f complex during cyclic electron transport in chloroplasts.

Analysis of the clinical antibacterial and antituberculosis pipeline.

This analysis of the global clinical antibacterial pipeline was done in support of the Global Action Plan on Antimicrobial Resistance. The study analysed to what extent antibacterial and antimycobacterial drugs for systemic human use as well as oral non-systemic antibacterial drugs for Clostridium difficile infections were active against pathogens included in the WHO priority pathogen list and their innovativeness measured by their absence of cross-resistance (new class, target, mode of action). As of July 1, 2018, 30 new chemical entity (NCE) antibacterial drugs, ten biologics, ten NCEs against Mycobacterium tuberculosis, and four NCEs against C difficile were identified. Of the 30 NCEs, 11 are expected to have some activity against at least one critical priority pathogen expressing carbapenem resistance. The clinical pipeline is dominated by derivatives of established classes and most development candidates display limited innovation. New antibacterial drugs without pre-existing cross-resistance are under-represented and are urgently needed, especially for geographical regions with high resistance rates among Gram-negative bacteria and M tuberculosis.

Construction of a fusion enzyme for astaxanthin formation and its characterisation in microbial and plant hosts: A new tool for engineering ketocarotenoids.

The high-value ketocarotenoid astaxanthin, a natural red colorant with powerful antioxidant activity, is synthesised from ß-carotene by a hydroxylase and an oxygenase enzyme, which perform the addition of two hydroxyl and keto moieties, respectively. Several routes of intermediates, depending on the sequence of action of these enzymes, lead to the formation of astaxanthin. In the present study, the enzyme activities of 3, 3' ß-carotene hydroxylase (CRTZ) and 4, 4' ß-carotene oxygenase (CRTW) have been combined through the creation of "new to nature" enzyme fusions in order to overcome leakage of non-endogenous intermediates and pleotropic effects associated with their high levels in plants. The utility of flexible linker sequences of varying size has been assessed in the construction of pZ-W enzyme fusions. Frist, in vivo color complementation assays in Escherichia coli have been used to evaluate the potential of the fusion enzymes. Analysis of the carotenoid pigments present in strains generated indicated that the enzyme fusions only possess both catalytic activities when CRTZ is attached as the N-terminal module. Astaxanthin levels in E. coli cells were increased by 1.4-fold when the CRTZ and CRTW enzymes were fused compared to the individual enzymes. Transient expression in Nicotiana benthamiana was then performed in order to assess the potential of the fusions in a plant system. The production of valuable ketocarotenoids was achieved using this plant-based transient expression system. This revealed that CRTZ and CRTW, transiently expressed as a fusion, accumulated similar levels of astaxanthin compared to the expression of the individual enzymes whilst being associated with reduced ketocarotenoid intermediate levels (e.g. phoenicoxanthin, canthaxanthin and 3-OH-echinenone) and a reduced rate of leaf senescence after transformation. Therefore, the quality of the plant material producing the ketocarotenoids was enhanced due to a reduction in the stress induced by the accumulation of high levels of heterologous ketocarotenoid intermediates. The size of the linkers appeared to have no effect upon activity. The potential of the approach to production of valuable plant derived products is discussed.

Enzyme Fusion Removes Competition for Geranylgeranyl Diphosphate in Carotenogenesis.

Geranylgeranyl diphosphate (GGPP), a prenyl diphosphate synthesized by GGPP synthase (GGPS), represents a metabolic hub for the synthesis of key isoprenoids, such as chlorophylls, tocopherols, phylloquinone, gibberellins, and carotenoids. Protein-protein interactions and the amphipathic nature of GGPP suggest metabolite channeling and/or competition for GGPP among enzymes that function in independent branches of the isoprenoid pathway. To investigate substrate conversion efficiency between the plastid-localized GGPS isoform GGPS11 and phytoene synthase (PSY), the first enzyme of the carotenoid pathway, we used recombinant enzymes and determined their in vitro properties. Efficient phytoene biosynthesis via PSY strictly depended on simultaneous GGPP supply via GGPS11. In contrast, PSY could not access freely diffusible GGPP or time-displaced GGPP supply via GGPS11, presumably due to liposomal sequestration. To optimize phytoene biosynthesis, we applied a synthetic biology approach and constructed a chimeric GGPS11-PSY metabolon (PYGG). PYGG converted GGPP to phytoene almost quantitatively in vitro and did not show the GGPP leakage typical of the individual enzymes. PYGG expression in Arabidopsis resulted in orange-colored cotyledons, which are not observed if PSY or GGPS11 are overexpressed individually. This suggests insufficient GGPP substrate availability for chlorophyll biosynthesis achieved through GGPP flux redirection to carotenogenesis. Similarly, carotenoid levels in PYGG-expressing callus exceeded that in PSY- or GGPS11-overexpression lines. The PYGG chimeric protein may assist in provitamin A biofortification of edible plant parts. Moreover, other GGPS fusions may be used to redirect metabolic flux into the synthesis of other isoprenoids of nutritional and industrial interest.