Exploring Antiviral Drugs on Monolayer Black Phosphorene: Atomistic Theory and Explainable Machine Learning-Assisted Platform.

Favipiravir (FP) and ebselen (EB) belong to a diverse class of antiviral drugs known for their significant efficacy in treating various viral infections. Utilizing molecular dynamics (MD) simulations, machine learning, and van der Waals density functional theory, we accurately elucidate the binding properties of these antiviral drugs on a phosphorene single-layer. To further investigate these characteristics, this study employs four distinct machine learning models-Random Forest, Gradient Boosting, XGBoost, and CatBoost. The Hamiltonian of antiviral molecules within a monolayer of phosphorene is appropriately trained. The key aspect of utilizing machine learning (ML) in drug design revolves around training models that are efficient and precise in approximating density functional theory (DFT). Furthermore, the study employs SHAP (SHapley Additive exPlanations) to elucidate model predictions, providing insights into the contribution of each feature. To explore the interaction characteristics and thermodynamic properties of the hybrid drug, we employ molecular dynamics and DFT calculations in a vacuum interface. Our findings suggest that this functionalized 2D complex exhibits robust thermostability, indicating its potential as an effective and enabled entity. The observed variations in free energy at different surface charges and temperatures suggest the adsorption potential of FP and EB molecules from the surrounding environment.

Treatment of vaginitis caused by non-albicans Candida species.

INTRODUCTION: In the face of increased frequency of non-albicans Candida vulvovaginitis (VVC) reported worldwide, there is a paucity of effective oral and topical antifungal drugs available. Drug selection is further handicapped by an absence of data of clinical efficacy of available antifungal drugs for these infections. AREAS COVERED: In this review, attention is directed at the cause of drug shortage as well as increased frequency of non-albicans Candida (NAC) vulvovaginitis. There is widespread recognition of reduced in vitro azole drug susceptibility in NAC species. Moreover, antifungal susceptibility tests have not been standardized or validated for NAC isolates, hence clinicians rely on an element of empiricism especially given the absence of randomized controlled comparative studies targeting NAC species. Clinical spectrum of NAC species isolates is highly variable with ongoing difficulty in determining a causal role in symptomatic patients. EXPERT OPINION: We have entered the era of demand for Candida species-specific therapy and although consensus treatment guidelines are emerging, new antifungal agents that target these multiple-azole resistant or relatively resistant vaginal NAC species are urgently needed.

Geldanamycin confers fungicidal properties to azole by triggering the activation of succinate dehydrogenase.

AIMS: Azoles have been widely employed for the treatment of invasive fungal diseases; however, their efficacy is diminished as pathogenic fungi tolerate them due to their fungistatic properties. Geldanamycin (GdA) can render azoles fungicidal by inhibiting the ATPase and molecular chaperone activities of heat shock protein 90 (Hsp90). Nonetheless, the clinical applicability of GdA is restricted due to its cytotoxic ansamycin scaffold structure, its induction of cytoprotective heat shock responses, and the conservative nature of Hsp90. Hence, it is imperative to elucidate the mechanism of action of GdA to confer fungicidal properties to azoles and mitigate the toxic adverse effects associated with GdA. MATERIALS AND METHODS: Through various experimental methods, including the construction of gene-deleted Candida albicans mutants, in vitro drug sensitivity experiments, Western blot analysis, reactive oxygen species (ROS) assays, and succinate dehydrogenase activity assays, we identified Hsp90 client proteins associated with the tolerance of C. albicans to azoles. KEY FINDINGS: It was observed that GdA effectively hindered the entry of Hsp90 into mitochondria, resulting in the alleviation of inhibitory effect of Hsp90 on succinate dehydrogenase. Consequently, the activation of succinate dehydrogenase led to an increased production of ROS. within the mitochondria, thereby facilitating the antifungal effects of azoles against C. albicans. SIGNIFICANCE: This research presents a novel approach for conferring fungicidal properties to azoles, which involves specifically disrupting the interaction of between Hsp90 and succinate dehydrogenase rather than employing a non-specific inhibition of ATPase activity of Hsp90.

Azoles activate type I and type II programmed cell death pathways in crop pathogenic fungi.

Triazoles are widely used to control pathogenic fungi. They inhibit the ergosterol biosynthetic pathway, but the precise mechanisms leading to fungicidal activities in many fungal pathogens are poorly understood. Here, we elucidate the mode of action of epoxiconazole and metconazole in the wheat pathogen Zymoseptoria tritici and the rice blast fungus Magnaporthe oryzae. We show that both azoles have fungicidal activity and reduce fluidity, but not integrity, of the plasma membrane. This impairs localisation of Cdc15-like F-BAR proteins, resulting in defective actin ring assembly and incomplete septation. However, mutant studies and pharmacological experiments in vitro and in planta show that azole lethality is due to a combination of reactive oxygen species-induced apoptosis and macroautophagy. Simultaneous inhibition of both programmed cell death pathways abolishes azole-induced cell death. Other classes of ergosterol biosynthesis inhibitors also induce apoptosis and macroautophagy, suggesting that activation of these two cell death pathways is a hallmark of ergosterol synthesis-targeting fungicides. This knowledge will inform future crop protection strategies.

Prevalence and genetic diversity of azole-resistant Malassezia pachydermatis isolates from canine otitis and dermatitis: A 2-year study.

Despite previous reports on the emergence of Malassezia pachydermatis strains with decreased susceptibility to azoles, there is limited information on the actual prevalence and genetic diversity of azole-resistant isolates of this yeast species. We assessed the prevalence of azole resistance in M. pachydermatis isolates from cases of dog otitis or skin disease attended in a veterinary teaching hospital during a 2-year period and analyzed the ERG11 (encoding a lanosterol 14-α demethylase, the primary target of azoles) and whole genome sequence diversity of a group of isolates that displayed reduced azole susceptibility. Susceptibility testing of 89 M. pachydermatis isolates from 54 clinical episodes (1-6 isolates/episode) revealed low minimum inhibitory concentrations (MICs) to most azoles and other antifungals, but 11 isolates from six different episodes (i.e., 12.4% of isolates and 11.1% of episodes) had decreased susceptibility to multiple azoles (fluconazole, itraconazole, ketoconazole, posaconazole, ravuconazole, and/or voriconazole). ERG11 sequencing of these 11 azole-resistant isolates identified eight DNA sequence profiles, most of which contained amino acid substitutions also found in some azole-susceptible isolates. Analysis of whole genome sequencing (WGS) results revealed that the azole-resistant isolates from the same episode of otitis, or even different episodes affecting the same animal, were more genetically related to each other than to isolates from other dogs. In conclusion, our results confirmed the remarkable ERG11 sequence variability in M. pachydermatis isolates of animal origin observed in previous studies and demonstrated the value of WGS for disentangling the epidemiology of this yeast species.

We analyzed the prevalence and diversity of azole-resistant Malassezia pachydermatis isolates in a veterinary hospital. A low prevalence of multi-azole resistance (c.10% of isolates and cases) was found. Whole genome and ERG11 sequencing of resistant isolates revealed remarkable genetic diversity.

Effects of ebselen addition on emotional processing and brain neurochemistry in depressed patients unresponsive to antidepressant medication.

Lithium is an effective augmenting agent for depressed patients with inadequate response to standard antidepressant therapy, but numerous adverse effects limit its use. We previously reported that a lithium-mimetic agent, ebselen, promoted a positive emotional bias-an indicator of potential antidepressant activity in healthy participants. We therefore aimed to investigate the effects of short-term ebselen treatment on emotional processing and brain neurochemistry in depressed patients with inadequate response to standard antidepressants. We conducted a double-blind, placebo-controlled 7-day experimental medicine study in 51 patients with major depressive disorder who were currently taking antidepressants but had an inadequate response to treatment. Participants received either ebselen 600 mg twice daily for seven days or identical matching placebo. An emotional testing battery, magnetic resonance spectroscopy and depression and anxiety rating scales were conducted at baseline and after seven days of treatment. Ebselen did not increase the recognition of positive facial expressions in the depressed patient group. However, ebselen increased the response bias towards fear emotion in the signal detection measurement. In the anterior cingulate cortex, ebselen significantly reduced the concentrations of inositol and Glx (glutamate+glutamine). We found no significant differences in depression and anxiety rating scales between visits. Our study did not find any positive shift in emotional bias in depressed patients with an inadequate response to antidepressant medication. We confirmed the ability of ebselen to lower inositol and Glx in the anterior cingulate cortex. These latter effects are probably mediated through inhibition of inositol monophosphatase and glutaminase respectively.

Spectrum of activity and mechanisms of azole-bisphosphonate synergy in pathogenic Candida.

Candidiasis places a significant burden on human health and can range from common superficial vulvovaginal and oral infections to invasive diseases with high mortality. The most common Candida species implicated in human disease is Candida albicans, but other species like Candida glabrata are emerging. The use of azole antifungals for treatment is limited by increasing rates of resistance. This study explores repositioning bisphosphonates, which are traditionally used for osteoporosis, as antifungal synergists that can improve and revitalize the use of azoles. Risedronate, alendronate, and zoledronate (ZOL) were tested against isolates from six different species of Candida, and ZOL produced moderate antifungal activity and strong synergy with azoles like fluconazole (FLC), particularly in C. glabrata. FLC:ZOL combinations had increased fungicidal and antibiofilm activity compared to either drug alone, and the combination prevented the development of antifungal resistance. Mechanistic investigations demonstrated that the synergy was mediated by the depletion of squalene, resulting in the inhibition of ergosterol biosynthesis and a compromised membrane structure. In C. glabrata, synergy compromised the function of membrane-bound multidrug transporters and caused an accumulation of reactive oxygen species, which may account for its acute sensitivity to FLC:ZOL. The efficacy of FLC:ZOL in vivo was confirmed in a Galleria mellonella infection model, where combinations improved the survival of larvae infected with C. albicans and C. glabrata to a greater extent than monotherapy with FLC or ZOL, and at reduced dosages. These findings demonstrate that bisphosphonates and azoles are a promising new combination therapy for the treatment of topical candidiasis. IMPORTANCE: Candida is a common and often very serious opportunistic fungal pathogen. Invasive candidiasis is a prevalent cause of nosocomial infections with a high mortality rate, and mucocutaneous infections significantly impact the quality of life of millions of patients a year. These infections pose substantial clinical challenges, particularly as the currently available antifungal treatment options are limited in efficacy and often toxic. Azoles are a mainstay of antifungal therapy and work by targeting the biosynthesis of ergosterol. However, there are rising rates of acquired azole resistance in various Candida species, and some species are considered intrinsically resistant to most azoles. Our research demonstrates the promising therapeutic potential of synergistically enhancing azoles with non-toxic, FDA-approved bisphosphonates. Repurposing bisphosphonates as antifungal synergists can bypass much of the drug development pipeline and accelerate the translation of azole-bisphosphonate combination therapy.

Ebselen analogues delay disease onset and its course in fALS by on-target SOD-1 engagement.

Amyotrophic lateral sclerosis (ALS) selectively affects motor neurons. SOD1 is the first causative gene to be identified for ALS and accounts for at least 20% of the familial (fALS) and up to 4% of sporadic (sALS) cases globally with some geographical variability. The destabilisation of the SOD1 dimer is a key driving force in fALS and sALS. Protein aggregation resulting from the destabilised SOD1 is arrested by the clinical drug ebselen and its analogues (MR6-8-2 and MR6-26-2) by redeeming the stability of the SOD1 dimer. The in vitro target engagement of these compounds is demonstrated using the bimolecular fluorescence complementation assay with protein-ligand binding directly visualised by co-crystallography in G93A SOD1. MR6-26-2 offers neuroprotection slowing disease onset of SOD1G93A mice by approximately 15 days. It also protected neuromuscular junction from muscle denervation in SOD1G93A mice clearly indicating functional improvement.

Study on the Antifungal Activity of Gallic Acid and Its Azole Derivatives against Fusarium graminearum.

The wheat scab caused by Fusarium graminearum (F. graminearum) has seriously affected the yield and quality of wheat in China. In this study, gallic acid (GA), a natural polyphenol, was used to synthesize three azole-modified gallic acid derivatives (AGAs1-3). The antifungal activity of GA and its derivatives against F. graminearum was studied through mycelial growth rate experiments and field efficacy experiments. The results of the mycelial growth rate test showed that the EC50 of AGAs-2 was 0.49 mg/mL, and that of AGAs-3 was 0.42 mg/mL. The biological activity of AGAs-3 on F. graminearum is significantly better than that of GA. The results of field efficacy tests showed that AGAs-2 and AGAs-3 significantly reduced the incidence rate and disease index of wheat scab, and the control effect reached 68.86% and 72.11%, respectively. In addition, preliminary investigation was performed on the possible interaction between AGAs-3 and F. graminearum using density functional theory (DFT). These results indicate that compound AGAs-3, because of its characteristic of imidazolium salts, has potential for use as a green and environmentally friendly plant-derived antifungal agent for plant pathogenic fungi.

Adhesive and biofilm-forming Candida glabrata Lebanese hospital isolates harbour mutations in subtelomeric silencers and adhesins.

BACKGROUND: The prevalence of Candida glabrata healthcare-associated infections is on the rise worldwide and in Lebanon, Candida glabrata infections are difficult to treat as a result of their resistance to azole antifungals and their ability to form biofilms. OBJECTIVES: The first objective of this study was to quantify biofilm biomass in the most virulent C. glabrata isolates detected in a Lebanese hospital. In addition, other pathogenicity attributes were evaluated. The second objective was to identify the mechanisms of azole resistance in those isolates. METHODS: A mouse model of disseminated systemic infection was developed to evaluate the degree of virulence of 41 azole-resistant C. glabrata collected from a Lebanese hospital. The most virulent isolates were further evaluated alongside an isolate having attenuated virulence and a reference strain for comparative purposes. A DNA-sequencing approach was adopted to detect single nucleotide polymorphisms (SNPs) leading to amino acid changes in proteins involved in azole resistance and biofilm formation. This genomic approach was supported by several phenotypic assays. RESULTS: All chosen virulent isolates exhibited increased adhesion and biofilm biomass compared to the isolate having attenuated virulence. The amino acid substitutions D679E and I739N detected in the subtelomeric silencer Sir3 are potentially involved- in increased adhesion. In all isolates, amino acid substitutions were detected in the ATP-binding cassette transporters Cdr1 and Pdh1 and their transcriptional regulator Pdr1. CONCLUSIONS: In summary, increased adhesion led to stable biofilm formation since mutated Sir3 could de-repress adhesins, while decreased azole susceptibility could result from mutations in Cdr1, Pdh1 and Pdr1.

Natural magnetite as an effective and long-lasting catalyst for CWPO of azole pesticides in a continuous up-flow fixed-bed reactor.

The global occurrence of micropollutants in water bodies has raised concerns about potential negative effects on aquatic ecosystems and human health. EU regulations to mitigate such widespread pollution have already been implemented and are expected to become increasingly stringent in the next few years. Catalytic wet peroxide oxidation (CWPO) has proved to be a promising alternative for micropollutant removal from water, but most studies were performed in batch mode, often involving complex, expensive, and hardly recoverable catalysts, that are prone to deactivation. This work aims to demonstrate the feasibility of a fixed-bed reactor (FBR) packed with natural magnetite powder for the removal of a representative mixture of azole pesticides, recently listed in the EU Watch Lists. The performance of the system was evaluated by analyzing the impact of H2O2 dose (3.6-13.4 mg L-1), magnetite load (2-8 g), inlet flow rate (0.25-1 mL min-1), and initial micropollutant concentration (100-1000 µg L-1) over 300 h of continuous operation. Azole pesticide conversion values above 80% were achieved under selected operating conditions (WFe3O4 = 8 g, [H2O2]0 = 6.7 mg L-1, flow rate = 0.5 mL min-1, pH0 = 5, T = 25 °C). Notably, the catalytic system showed a high stability upon 500 h in operation, with limited iron leaching (< 0.1 mg L-1). As a proof of concept, the feasibility of the system was confirmed using a real wastewater treatment plant (WWTP) effluent spiked with the mixture of azole pesticides. These results represent a clear advance for the application of CWPO as a tertiary treatment in WWTPs and open the door for the scale-up of FBR packed with natural magnetite.

Azole resistance mechanisms and population structure of the human pathogen Aspergillus fumigatus on retail plant products.

Aspergillus fumigatus is a ubiquitous saprotroph and human-pathogenic fungus that is life-threatening to the immunocompromised. Triazole-resistant A. fumigatus was found in patients without prior treatment with azoles, leading researchers to conclude that resistance had developed in agricultural environments where azoles are used against plant pathogens. Previous studies have documented azole-resistant A. fumigatus across agricultural environments, but few have looked at retail plant products. Our objectives were to determine if azole-resistant A. fumigatus is prevalent in retail plant products produced in the United States (U.S.), as well as to identify the resistance mechanism(s) and population genetic structure of these isolates. Five hundred twenty-five isolates were collected from retail plant products and screened for azole resistance. Twenty-four isolates collected from compost, soil, flower bulbs, and raw peanuts were pan-azole resistant. These isolates had the TR34/L98H, TR46/Y121F/T289A, G448S, and H147Y cyp51A alleles, all known to underly pan-azole resistance, as well as WT alleles, suggesting that non-cyp51A mechanisms contribute to pan-azole resistance in these isolates. Minimum spanning networks showed two lineages containing isolates with TR alleles or the F46Y/M172V/E427K allele, and discriminant analysis of principle components identified three primary clusters. This is consistent with previous studies detecting three clades of A. fumigatus and identifying pan-azole-resistant isolates with TR alleles in a single clade. We found pan-azole resistance in U.S. retail plant products, particularly compost and flower bulbs, which indicates a risk of exposure to these products for susceptible populations and that highly resistant isolates are likely distributed worldwide on these products.IMPORTANCEAspergillus fumigatus has recently been designated as a critical fungal pathogen by the World Health Organization. It is most deadly to people with compromised immune systems, and with the emergence of antifungal resistance to multiple azole drugs, this disease carries a nearly 100% fatality rate without treatment or if isolates are resistant to the drugs used to treat the disease. It is important to determine the relatedness and origins of resistant A. fumigatus isolates in the environment, including plant-based retail products, so that factors promoting the development and propagation of resistant isolates can be identified.

Pan-azole- and multi-fungicide-resistant Aspergillus fumigatus is widespread in the United States.

Aspergillus fumigatus is an important global fungal pathogen of humans. Azole drugs are among the most effective treatments for A. fumigatus infection. Azoles are also widely used in agriculture as fungicides against fungal pathogens of crops. Azole-resistant A. fumigatus has been increasing in Europe and Asia for two decades where clinical resistance is thought to be driven by agricultural use of azole fungicides. The most prevalent mechanisms of azole resistance in A. fumigatus are tandem repeats (TR) in the cyp51A promoter coupled with mutations in the coding region which result in resistance to multiple azole drugs (pan-azole resistance). Azole-resistant A. fumigatus has been isolated from patients in the United States (U.S.), but little is known about its environmental distribution. To better understand the distribution of azole-resistant A. fumigatus in the U.S., we collected isolates from agricultural sites in eight states and tested 202 isolates for sensitivity to azoles. We found azole-resistant A. fumigatus in agricultural environments in seven states showing that it is widespread in the U.S. We sequenced environmental isolates representing the range of U.S. sample sites and compared them with publicly available environmental worldwide isolates in phylogenetic, principal component, and ADMIXTURE analyses. We found worldwide isolates fell into three clades, and TR-based pan-azole resistance was largely in a single clade that was strongly associated with resistance to multiple agricultural fungicides. We also found high levels of gene flow indicating recombination between clades highlighting the potential for azole-resistance to continue spreading in the U.S.IMPORTANCEAspergillus fumigatus is a fungal pathogen of humans that causes over 250,000 invasive infections each year. It is found in soils, plant debris, and compost. Azoles are the first line of defense antifungal drugs against A. fumigatus. Azoles are also used as agricultural fungicides to combat other fungi that attack plants. Azole-resistant A. fumigatus has been a problem in Europe and Asia for 20 years and has recently been reported in patients in the United States (U.S.). Until this study, we did not know much about azole-resistant A. fumigatus in agricultural settings in the U.S. In this study, we isolated azole-resistant A. fumigatus from multiple states and compared it to isolates from around the world. We show that A. fumigatus which is resistant to azoles and to other strictly agricultural fungicides is widespread in the U.S.

Hospital distribution, seasonality, time trends and antifungal susceptibility profiles of all Aspergillus species isolated from clinical samples from 2015 to 2022 in a tertiary care hospital.

BACKGROUND: Aspergillus species cause a variety of serious clinical conditions with increasing trend in antifungal resistance. The present study aimed at evaluating hospital epidemiology and antifungal susceptibility of all isolates recorded in our clinical database since its implementation. METHODS: Data on date of isolation, biological samples, patients' age and sex, clinical settings, and antifungal susceptibility tests for all Aspergillus spp. isolated from 2015 to 2022 were extracted from the clinical database. Score test for trend of odds, non-parametric Mann Kendall trend test and logistic regression analysis were used to analyze prevalence, incidence, and seasonality of Aspergillus spp. isolates. RESULTS: A total of 1126 Aspergillus spp. isolates were evaluated. A. fumigatus was the most prevalent (44.1%) followed by A. niger (22.3%), A. flavus (17.7%) and A. terreus (10.6%). A. niger prevalence increased over time in intensive care units (p-trend = 0.0051). Overall, 16 (1.5%) were not susceptible to one azole compound, and 108 (10.9%) to amphotericin B, with A. niger showing the highest percentage (21.9%). The risk of detecting A. fumigatus was higher in June, (OR = 2.14, 95% CI [1.16; 3.98] p = 0.016) and reduced during September (OR = 0.48, 95% CI [0.27; 0.87] p = 0.015) and October as compared to January (OR = 0.39, 95% CI [0.21; 0.70] p = 0.002. A. niger showed a reduced risk of isolation from all clinical samples in the month of June as compared to January (OR = 0.34, 95% CI [0.14; 0.79] p = 0.012). Seasonal trend for A. flavus showed a higher risk of detection in September (OR = 2.7, 95% CI [1.18; 6.18] p = 0.019), October (OR = 2.32, 95% CI [1.01; 5.35] p = 0.048) and November (OR = 2.42, 95% CI [1.01; 5.79] p = 0.047) as compared to January. CONCLUSIONS: This is the first study to analyze, at once, data regarding prevalence, time trends, seasonality, species distribution and antifungal susceptibility profiles of all Aspergillus spp. isolates over a 8-year period in a tertiary care center. Surprisingly no increase in azole resistance was observed over time.

[Antimicrobial peptides: A new alternative for the treatment of aspergillosis]. / Peptides antimicrobiens : une nouvelle alternative pour le traitement des aspergilloses.

Aspergillus fumigatus is the predominant fungal species causing pulmonary aspergillosis. The present-day anti-aspergillosis arsenal is limited, with a number of molecules occasioning severe side effects (amphotericin B) or provoking significant drug interactions (azole derivatives). Moreover, the recent emergence of azole-resistant A. fumigatus strains is a cause for concern. In this context, antimicrobial peptides (AMPs) are emerging as a promising therapeutic approach and alternative or complement to conventional antifungals.

Searching for Conjugates as New Structures for Antifungal Therapies.

The progressive increase in fungal infections and the decrease in the effectiveness of current therapy explain research on new drugs. The synthesis of compounds with proven antifungal activity, favorable physicochemical and pharmacokinetic properties affecting their pharmaceutical availability and bioavailability, and limiting or eliminating side effects has become the goal of many studies. The publication describes the directions of searching for new compounds with antifungal activity, focusing on conjugates. The described modifications include, among others, azoles or amphotericin B in combination with fatty acids, polysaccharides, proteins, and synthetic polymers. The benefits of these combinations in terms of activity, mechanism of action, and bioavailability were indicated. The possibilities of creating or using nanoparticles, "umbrella" conjugates, siderophores (iron-chelating compounds), and monoclonal antibodies were also presented. Taking into account the role of vaccinations in prevention, the scope of research related to developing a vaccine protecting against fungal infections was also indicated.

Toxic interactions at the physiological and biochemical levels of green algae under stress of mixtures of three azole fungicides.

Assessing the interactions between environmental pollutants and these mixtures is of paramount significance in understanding their negative effects on aquatic ecosystems. However, existing research often lacks comprehensive investigations into the physiological and biochemical mechanisms underlying these interactions. This study aimed to reveal the toxic mechanisms of cyproconazole (CYP), imazalil (IMA), and prochloraz (PRO) and corresponding these mixtures on Auxenochlorella pyrenoidosa by analyzing the interactions at physiological and biochemical levels. Higher concentrations of CYP, IMA, and PRO and these mixtures resulted in a reduction in chlorophyll (Chl) content and increased total protein (TP) suppression, and malondialdehyde (MDA) content exhibited a negative correlation with algal growth. The activity of catalase (CAT) and superoxide dismutase (SOD) decreased with increasing azole fungicides and their mixture concentrations, correlating positively with growth inhibition. Azole fungicides induced dose-dependent apoptosis in A. pyrenoidosa, with higher apoptosis rates indicative of greater pollutant toxicity. The results revealed concentration-dependent toxicity effects, with antagonistic interactions at low concentrations and synergistic effects at high concentrations within the CYP-IMA mixtures. These interactions were closely linked to the interactions observed in Chl-a, carotenoid (Car), CAT, and cellular apoptosis. The antagonistic effects of CYP-PRO mixtures on A. pyrenoidosa growth inhibition can be attributed to the antagonism observed in Chl-a, Chl-b, Car, TP, CAT, SOD, and cellular apoptosis. This study emphasized the importance of gaining a comprehensive understanding of the physiological and biochemical interactions within algal cells, which may help understand the potential mechanism of toxic interaction.

COVID-19 associated candidemia: From a shift in fungal epidemiology to a rise in azole drug resistance.

Our understanding of fungal epidemiology and the burden of antifungal drug resistance in COVID-19-associated candidemia (CAC) patients is limited. Therefore, we conducted a retrospective multicenter study in Iran to explore clinical and microbiological profiles of CAC patients. Yeast isolated from blood, were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and subjected to antifungal susceptibility testing (AFST) using the broth microdilution method M27-A3 protocol. A total of 0.6% of the COVID-19 patients acquired CAC (43/6174). Fluconazole was the most widely used antifungal, and 37% of patients were not treated. Contrary to historic candidemia patients, Candida albicans and C. tropicalis were the most common species. In vitro resistance was high and only noted for azoles; 50%, 20%, and 13.6% of patients were infected with azole-non-susceptible (ANS) C. tropicalis, C. parapsilosis, and C. albicans isolates, respectively. ERG11 mutations conferring azole resistance were detected for C. parapsilosis isolates (Y132F), recovered from an azole-naïve patient. Our study revealed an unprecedented rise in ANS Candida isolates, including the first C. parapsilosis isolate carrying Y132F, among CAC patients in Iran, which potentially threatens the efficacy of fluconazole, the most widely used drug in our centers. Considering the high mortality rate and 37% of untreated CAC cases, our study underscores the importance of infection control strategies and antifungal stewardship to minimize the emergence of ANS Candida isolates during COVID-19.

Distribution of Aspergillus species and prevalence of azole resistance in clinical and environmental samples from a Spanish hospital during a three-year study period.

BACKGROUND: Surveillance studies are crucial for updating trends in Aspergillus species and antifungal susceptibility information. OBJECTIVES: Determine the Aspergillus species distribution and azole resistance prevalence during this 3-year prospective surveillance study in a Spanish hospital. MATERIALS AND METHODS: Three hundred thirty-five Aspergillus spp. clinical and environmental isolates were collected during a 3-year study. All isolates were screened for azole resistance using an agar-based screening method and resistance was confirmed by EUCAST antifungal susceptibility testing. The azole resistance mechanism was confirmed by sequencing the cyp51A gene and its promoter. All Aspergillus fumigatus strains were genotyped using TRESPERG analysis. RESULTS: Aspergillus fumigatus was the predominant species recovered with a total of 174 strains (51.94%). The rest of Aspergillus spp. were less frequent: Aspergillus niger (14.93%), Aspergillus terreus (9.55%), Aspergillus flavus (8.36%), Aspergillus nidulans (5.37%) and Aspergillus lentulus (3.28%), among other Aspergillus species (6.57%). TRESPERG analysis showed 99 different genotypes, with 72.73% of the strains being represented as a single genotype. Some genotypes were common among clinical and environmental A. fumigatus azole-susceptible strains, even when isolated months apart. We describe the occurrence of two azole-resistant A. fumigatus strains, one clinical and another environmental, that were genotypically different and did not share genotypes with any of the azole-susceptible strains. CONCLUSIONS: Aspergillus fumigatus strains showed a very diverse population although several genotypes were shared among clinical and environmental strains. The isolation of azole-resistant strains from both settings suggest that an efficient analysis of clinical and environmental sources must be done to detect azole resistance in A. fumigatus.

Exposure to resistant fungi across working environments and time.

Antifungal resistance has emerged as a significant health concern with increasing reports of resistant variants in previously susceptible species. At present, little is known about occupational exposure to antifungal-resistant fungi. This study aimed to investigate Danish workers' occupational exposure to airborne fungi resistant to first-line treatment drugs. A retrospective study was performed on a unique collection of personal exposure samples gathered over a twenty-year period from Danish working environments, in sectors including agriculture, animal handling, waste management, and healthcare. A total of 669 samples were cultivated at 37 °C and fungal colonies were identified using MALDI-TOF MS. Subsequently, identification was confirmed by amplicon sequencing the genes of calmodulin and beta-tubulin to unveil potential cryptic species. Infectious fungi (495 isolates from 23 species) were tested for resistance against Itraconazole, Voriconazole, Posaconazole, and Amphotericin B. Working environments were highly variable in the overall fungal exposure, and showed vastly different species compositions. Resistance was found in 30 isolates of the species Aspergillus fumigatus (4 of 251 isolates), A. nidulans (2 of 13), A. niger complex (19 of 131), A. versicolor (3 of 18), and A. lentulus (2 of 2). Sequence analysis revealed several cryptic species within the A. niger complex including A. tubingensis, A. luchuensis, and A. phoenicis. Among the resistant A. fumigatus isolates, two contained the well-described TR34/L98H mutation in the cyp51A gene and promoter region, while the remainder harbored silent mutations. The results indicate that the working environment significantly contributes to exposure to resistant fungi, with particularly biofuel plant workers experiencing high exposure. Differences in the prevalence of resistance across working environments may be linked to the underlying species composition.