The changing epidemiology of fungal infections

Severe oropharyngeal candidiasis in an anemic pregnant woman: A case report

Hormonal fluctuations during pregnancy increase susceptibility to Candida infections, typically presenting as vulvovaginal candidiasis, but rarely as oropharyngeal candidiasis. We report a rare case of a woman being pregnant for 27 + 1 weeks with twins with oropharyngeal candidiasis, likely attributed to nutritional anemia and adverse reactions of amoxicillin. Following a thorough literature review and evaluation of medication safety during pregnancy regarding route, dosage, and gestational stage, we treated the patient with fluconazole and piperacillin-tazobactam. The patient fully recovered and successfully delivered two infants via cesarean section at term, with no adverse reactions noted during a six-month follow-up.

Berberine disrupts the high-affinity iron transport system to reverse the fluconazole-resistance in Candida albicans

Invasive fungal infection is usually caused by Candida albicans infection, which has a high incidence rate and mortality in critically ill patients. New drugs are needed to combat this pathogen since the limited treatment options currently available and increasing resistance to existing drugs. Berberine (BBR) is an active compound in Coptis chinensis, Phellodendron chinense and Radix berberidis, which is clinically used to treat inflammatory bowel disease, but its inhibitory effect on drug-resistant fungi has not been clarified. In this study, based on the evidence of BBR inhibiting the expression of azole-resistance genes, reducing cell adhesion and disrupting biofilm formation, transcriptome analysis revealed that the disruption of iron acquisition pathway may be the core link in BBR inhibiting drug-resistant fungi. Combined with the subsequent experimental results, including the reduction of intracellular ferrous ion content, the weakening of iron reductase activity and the overall downregulation of the coding gene of the high-affinity iron reduction system, it is speculated that the fungal growth defect under BBR treatment is the result of the interruption of the high-affinity iron acquisition pathway. Ftr1 plays a central role in the drug targeting of this transport system. Meanwhile, due to the iron deficiency within the cell, the biological function of mitochondria is impaired, ultimately leading to fungal death. This study not only reflects the application value of BBR in the clinical treatment of fungal infections, but also provides a potential strategy to address the current drug-resistance dilemma.

Antifungal activity of guanidine compounds

Guanidinic compounds are a class of compounds distributed in nature but also synthesized in vitro with a wide variety of applicability. One of the potentials of those molecules is antimicrobial activity. In that sense, although mainly limited to immunocompromised people, fungi pathogens are a cause of concern, even more so after the COVID-19 pandemic. Susceptible groups and increased geographical distribution, besides drug toxicity, resistance, and high costs, made the World Health Organization (WHO) establish a guideline for research and public health politics against different fungi opportunist agents. Our present work evaluated the antifungal activity of 11 guanidine compounds (one of them synthesized for the first time) against six fungi species in the WHO Fungi Priority Pathogens List and their potential for antimicrobial selectivity. The newly synthesized compound, named LQOF-G2-S, was successfully obtained and chemically characterized as spermidine tri-substituted by guanidine moieties in benzylamine-4-bromoaniline groups, and it presented the best antifungal activity and selectivity among the others. It was the only compound active against Candida spp.; however, its activity was more promising against Cryptococcus neoformans, Cryptococcus gattii, and even more against Paracoccidioides brasiliensis and Paracoccidioides lutzii, with a selective index higher than 10. The LQOF-G2-S potential opened up the opportunity to design and evaluate other similar compounds, contributing to finding new effective, less toxic, and more affordable compounds for fungi treatment.

Candidiasis: Insights into Virulence Factors, Complement Evasion and Antifungal Drug Resistance

Invasive fungal infections constitute a substantial global health burden, with invasive candidiasis representing approximately 70% of reported cases worldwide. The emergence of antifungal resistance among Candida species has further exacerbated this challenge to healthcare systems. Recent epidemiological studies have documented a concerning shift towards non-albicans Candida species, exhibiting reduced antifungal susceptibility, in invasive candidiasis cases. The complement system serves as a crucial first-line defence mechanism against Candida infections. These fungal pathogens can activate the complement cascade through three conventional pathways-classical, lectin, and alternative-in addition to activation through the coagulation system. While these pathways are initiated by distinct molecular triggers, they converge at C3 convertase formation, ultimately generating biologically active products and the membrane attack complex. Candida species have evolved sophisticated mechanisms to evade complement-mediated host defence, including the masking of cell wall components, proteolytic cleavage and inhibition of complement proteins, recruitment of complement regulators, and acquisition of host proteins. This review examines the intricate interplay between Candida species and the host complement system, with emphasis on complement evasion strategies. Furthermore, we highlight the importance of exploring the crosstalk between antifungal resistance and immune evasion strategies employed by Candida species. Understanding these interactions may facilitate the development of novel therapeutic approaches and strategies to overcome treatment failures in Candida species infections.

The Antidepressant Sertraline Modulates Gene Expression and Alternative Splicing Events in the Dermatophyte Trichophyton rubrum: A Comprehensive Analysis

BACKGROUND/OBJECTIVES

Dermatophytosis, a prevalent fungal infection of keratinized tissues, is primarily caused by the filamentous fungus Trichophyton rubrum. Sertraline (SRT), an antidepressant with antifungal activity, has already demonstrated therapeutic potential against this fungus. Elucidating the effects of SRT may provide insights into its mechanism of action and fungal adaptation to this drug. Differential gene expression and alternative splicing (AS) facilitate fungal adaptations to various environmental conditions. This study aimed to provide a comprehensive overview of AS events and their implications in T. rubrum cultivated under sub-inhibitory concentrations of SRT.

METHOD

The transcriptome of T. rubrum challenged with SRT was analyzed to detect AS events.

RESULTS

RNA-seq analysis revealed that SRT affected transcriptional and post-transcriptional events in numerous T. rubrum genes, including those encoding transcription factors, kinases, and efflux pumps. Among the AS events, intron retention was predominant. After 12 h of SRT exposure, intron-3 retention levels in the serine/arginine protein kinase mRNA transcripts were significantly increased compared with those in the control. This new isoform would produce a putative protein that partially lost its phosphotransferase domain.

CONCLUSIONS

These findings highlight the potential mechanisms of action of SRT and suggest how T. rubrum adapts itself to this drug.

Recognizing the Importance of Public Health Mycology

Fungal diseases are an emerging global public health concern, affecting high-, low-, and middle-income countries [...].

Peripheral blood lymphocyte subsets combined with fungal biomarkers in the diagnosis of invasive fungal infections complicated by sepsis

OBJECTIVE

To evaluate the lymphocyte subpopulations and the levels of (1, 3)-β-d-glucan (BDG) and galactomannan (GAL) in sepsis patients with secondary invasive fungal infections (IFIs), and to investigate the association between lymphocytes and IFIs.

METHODS

A retrospective case-control study of 47 patients with sepsis complicated by IFIs, 50 sepsis patients, and 50 healthy controls was conducted. The correlation between lymphocyte subsets and BDG, GAL levels was analyzed using the Spearman correlation method, and the diagnostic efficacy of IFIs-related factors was assessed using the receiver operating characteristic curve (ROC) analysis.

RESULTS

The IFIs group exhibited significantly lower absolute lymphocyte counts (P < 0.05). The study revealed that both BDG and GAL levels were inversely correlated with the counts of total lymphocytes and CD4+ lymphocytes (BDG: R2 = 0.361, 0.283; GAL: R2 =0.257, 0.375, P < 0.05). The area under the curve (AUC) for the combined diagnostic markers was as follows: BDG and GAL alone had an AUC of 0.753; BDG and GAL in conjunction with lymphocyte count had an AUC of 0.921; and the combination of BDG, GAL, lymphocyte count, and CD4 T lymphocyte count achieved an AUC of 0.962. The sensitivities for these combinations were 80.00 %, 80.85 %, and 87.23 %, respectively, while the specificities were 60.00 %, 96.0 %, and 98.00 %, respectively.

CONCLUSIONS

The reduced absolute counts of lymphocyte subsets in patients with IFIs complicated by sepsis suggest a state of immunosuppression. The concurrent assessment of BDG, GAL, total lymphocyte count, and CD4 T lymphocyte count demonstrates high diagnostic efficacy for identifying IFIs complicated by sepsis.

n -butanol fraction of Terminalia catappa possesses anti-Candida albicans properties and in vivo action on Tenebrio molitor alternative infection model

Current treatment of Candida infections is threatened by antifungal drug resistance. Thus, medicinal plants have been studied to identify new and highly effective antifungal substances with low toxicity. Here, we showed that the tannin-rich n-butanol fraction of Terminalia catappa (FBuOH) possesses antifungal and antibiofilm properties and protects Tenebrio molitor larvae against Candida albicans infection. FBuOH showed antifungal activity against Candida spp. vaginal isolates (MIC values ranged from 7 to 500 μg/mL). Moreover, a combination of FBuOH with fluconazole (FICI ≤0.5) showed considerably increased anti-yeast, anti-biofilm activity and significantly improved the survival rate (up to 100 %) of T. molitor larvae against C. albicans infection. Furthermore, FBuOH acted synergistically with fluconazole by reducing C. albicans membrane ergosterol content. These results could also explain the synergistic activity between FBuOH and fluconazole, indicating that FBuOH exerted its effects on C. albicans membrane integrity, increasing its permeability. Our findings provide insights into the antifungal activity and low cytotoxicity of FBuOH, showing its potential use as a new antimycotic.

Evidence-based clinical standard for the diagnosis and treatment of candidemia in critically ill patients in the intensive care unit

Candidemia is the predominant form of invasive candidiasis and the most frequently occurring serious fungal infection in critically ill patients in Intensive Care Units (ICU). Studies carried out in Latin America reveal a higher incidence of candidemia and higher mortality rates when compared to North America or Europe. This highlights the need to develop guidelines for correctly diagnosing and treating candidemia in critically ill patients in the ICU. These guidelines are part of the efforts to implement antifungal optimization programs in the region to obtain better clinical outcomes and promote rational antifungal use. This evidence-based clinical standard, established through expert consensus for the Latin American context, contains recommendations and algorithms for diagnosing and treating candidemia in critically ill ICU patients.

Cryptococcus neoformans/gattii and Histoplasma capsulatum var. capsulatum infections on tissue sections: Diagnostic pitfalls and relevance of an integrated histomolecular diagnosis

Cryptococcus neoformans/gattii and Histoplasma capsulatum var. capsulatum may present atypical histopathological features inducing diagnostic errors. We aimed to estimate the frequency of these atypical features in formalin-fixed tissue (FT) samples and to assess the relevance of an integrated histomolecular diagnosis using specific H. capsulatum PCR and panfungal PCR followed by Sanger sequencing and/or targeted massive parallel sequencing (MPS). A total of 27 FT from 23 patients with a histopathological diagnosis of cryptococcosis (n = 16 FT from 13 patients) or histoplasmosis (n = 11 FT from 10 patients) were retrospectively included. All FT were consultation cases. Mycological identifications on equivalent fresh tissue were available for 11/23 (47.8%) patients. The expert pathologist review modified the diagnosis suggested by the initial pathologist in 7/27 (25.9%) FT. Fungal morphology and tissue inflammation were compared between both mycoses. The most discriminant atypical criterion was the presence of dented-looking yeasts, observed in 68.75% (11/16) of C. neoformans/gattii and none (0/11) of H. capsulatum var. capsulatum (P = .002). For the 12/23 (52.2%) patients without mycological identification on fresh tissue, an integrated histomolecular diagnosis on FT using specific PCR or panfungal PCR followed by Sanger sequencing and/or MPS led to fungal identification in 9/12 (75%) cases; for cryptococcosis, the targeted MPS sensitivity was higher than that of Sanger sequencing (P = .041). Thus, because atypical histopathological features may be tricky, integrated histomolecular diagnosis is essential for optimal patient care.

Threats from the Candida parapsilosis complex: the surge of multidrug resistance and a hotbed for new emerging pathogens

SUMMARYCandida parapsilosis is a common agent of candidiasis that has gained increased attention in recent years, culminating with its recent consideration as a high-priority fungal pathogen by the World Health Organization. Reasons for this classification are the recent surge in incidence and the alarmingly growing rates of drug and multidrug resistance. In addition, several closely related species such as Candida metapsilosis and Candida orthopsilosis may represent recently emerged opportunistic pathogens originated from environmental niches through interspecies hybridization. Here, I review recent research focused on the potential origin and spread of drug resistance and of emerging species in this complex. I will also discuss open questions regarding the possible implications of human activities in these two epidemiological phenomena.

Serum antigen tests for the diagnosis of invasive aspergillosis: a retrospective comparison of five Aspergillus antigen assays and one beta-D-glucan assay

Invasive aspergillosis (IA) is a life-threatening infection. Early and specific diagnosis is pivotal to ensure adequate therapy. Antigen testing from blood is a widespread and convenient diagnostic approach. Various tests for the detection of Aspergillus antigen as well as for the panfungal antigen β-1,3-D-glucan (BDG) are available, for which comprehensive comparisons are still lacking. Blood samples of 82 proven/probable (11/71) IA patients and 52 controls were tested using two enzyme-linked immunosorbent assays (ELISAs) (Bio-Rad and Euroimmun), one chemiluminescent immunoassay (CLIA) (Vircell), one BDG assay (Fujifilm Wako), and two point of care (PoC) assays (Immy sōna and OLM). PoC assays were evaluated visually and used automated read out systems. Of the 82 IA patients, 37 had received solid organ transplantation (SOT) and 25 hematopoietic stem cell transplant (HSCT). Sensitivities and specificities for the eight test systems ranged from 27% to 71% and from 64% to 100%. Estimating a 10% prevalence of IA, test performance would have resulted in positive and negative predictive values of 14%-100% and 91%-95%. Areas under the curve (AUCs) for all tests except GM were below 0.7. When the cut-off values for quantitative tests were normalized to a specificity close to 95%, sensitivities ranged from 14% to 40%. The use of automated read out systems for the PoC assays had a significant impact. Combining different tests did not result in better test strategies. Sensitivity of Aspergillus antigen testing from single serum samples is low. Due to specificity issues, the majority of tests is not suited for screening purposes. The different assays can meet different needs in different diagnostic settings.

Effectiveness of combined proton pump inhibitors and posaconazole prophylaxis against invasive fungal infections in patients with hematologic malignancies: a retrospective study

BACKGROUND

Posaconazole is widely recommended for preventing and treating invasive fungal infections (IFIs) in immunocompromised patients, especially those with prolonged neutropenia. However, the concentration of the oral suspension formulation can be affected by factors such as co-administration with acid-suppressing medications, influencing its efficacy and safety.

AIM

This study examined the impact of proton pump inhibitors (PPIs) and other factors on posaconazole concentrations and the concentration-to-dose ratio (C/D) while also evaluating adverse drug reactions in patients with hematologic malignancies.

METHOD

We conducted a retrospective analysis of patients who received posaconazole for IFI prophylaxis or treatment, assessing demographic and clinical data, adverse reactions, treatment outcomes, and drug concentration assays. The study focused on the effects of PPIs on Cmin and C/D.

RESULTS

Data from 283 posaconazole Cmin measurements in 86 patients were analyzed. The incidence of probable or proven IFIs was 6.4% (5/78). PPI use reduced posaconazole Cmin levels but did not significantly impact prophylactic efficacy. Esomeprazole and rabeprazole were explicitly associated with decreased Cmin. Hepatotoxicity was linked to the co-administration of hepatotoxic drugs, indicating that posaconazole was not the sole contributor.

CONCLUSION

Co-administration of esomeprazole or rabeprazole lowers posaconazole plasma concentrations without compromising prophylactic efficacy against IFIs. Nonetheless, caution is advised when combining these drugs in high-risk immunocompromised patients.

Comparative Analysis of In-House and Commercially Available Media for Determining the Antifungal Susceptibility Profile of Candida Species

Background The emergence of treatment-resistant Candida species has highlighted the importance of antifungal susceptibility testing as it is difficult to determine therapeutics solely based on species identification. However, as compared to bacterial pathogens, antimicrobial susceptibility testing in fungi still remains underutilized in most clinical diagnostic microbiological services. The disc diffusion (DD) technique is reported to be easy and cost-effective and therefore can be easily incorporated as a routine method. However, the selection of media remains the most crucial factor for antifungal susceptibility testing using the DD method. In the present study, in-house prepared and commercially available Mueller-Hinton agar with 2% glucose and 0.5 μg/ml methylene blue dye (MH-GMB) for determining the antifungal susceptibility profile of Candida species. Method The study involved 165 strains of eight different Candida species obtained from various clinical specimens. MH-GMB was the media used for antifungal susceptibility testing of Candida strains, and the efficacy of in-house and commercially available MH-GMB was compared. Results All Candida isolates showed sufficient growth on readymade MH-GMB procured from commercial sources. The frequency of trailing phenomenon was very low in MH-GMB procured from commercial sources. The visualization of zone margins was more enhanced with commercially procured MH-GMB compared to in-house media. Conclusion As per the available literature, the present study is the first to report the comparative account of in-house prepared and commercially procured MH-GMB for antifungal susceptibility testing of Candida spp. Commercially procured MH-GMB appears to be more advantageous over in-house prepared media as there is rapid growth, infrequent appearance trailing phenomenon, and more clear zone diameters. It is easy to weigh and prepare. Since it is pre-formulated, there is no chance of preparation error.

Multi-omics analysis reveals indicator features of microbe-host interactions during Candida albicans colonization and subsequent infection

Introduction

Candida albicans gastrointestinal (GI) colonization is crucial for the onset of invasive disease. This research encompassed 31 patients diagnosed with Candida spp. bloodstream infections during their admission to a university hospital in China.

Methods

We explored risk factors associated with C. albicans GI colonization and ensuing translocated infection. Animal models were established via gavage with clinical isolates of C. albicans to induce GI tract colonization and subsequent kidney translocation infection. Our analysis is focused on 16S rRNA gene sequencing, metabolomics of colon contents, and transcriptomics of colon tissues, examining the intestinal barrier, inflammatory responses, and immune cell infiltration.

Results

This study observed that down-regulation of programmed cell death 1 (PD-1) in colon tissues is likely linked to the progression from C. albicans colonization to translocated infection. Notably, reductions in Dubosiella abundance and Short-chain fatty acids (SCFA) levels, coupled with increases in Mucispirillum and D-erythro-imidazolylglycerol phosphate, were indicator features during the advancement to translocated invasive infection in hosts with rectal colonization by C. albicans and lower serum protein levels.

Conclusion

Given the similarity in intestinal bacterial communities and metabolome profiles, antifungal treatment may not be necessary for patients with nonpathogenic C. albicans colonization. The reduced expression of PD-1 in colon tissues may contribute to the transition from colonized C. albicans to subsequent translocated infection. The indicator features of decreased Dubosiella abundance and SCFA levels, coupled with increased Mucispirillum and D-erythro-imidazolylglycerol phosphate, are likely linked to the development of translocated invasive infection in hosts colonized rectally by C. albicans with lower serum protein levels.

Importance

Candida albicans invasive infections pose a significant challenge to contemporary medicine, with mortality rates from such fungal infections remaining high despite antifungal treatment. Gastrointestinal colonization by potential pathogens is a critical precursor to the development of translocated infections. Consequently, there is an increasing demand to identify clinical risk factors, multi-omics profiles, and key indicators to prevent the progression to translocated invasive infections in patients colonized rectally by C. albicans.

Candida guilliermondii fungemia: a 12-year retrospective review of antimicrobial susceptibility patterns at a reference laboratory and tertiary care center

The prevalence of invasive candidiasis caused by non-albicans Candida species is increasing. Candida guilliermondii is an infrequent cause of candidemia but has been associated with decreased susceptibility to triazoles. Clinical data related to the infection with C. guilliermondii are sparse. Our study evaluated the antifungal susceptibility testing (AST) for C. guilliermondii isolates submitted to a reference laboratory over a 12-year period (2012-2023). AST patterns were examined using Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST) epidemiological cutoff values (ECVs) and breakpoints. Where isolates were identified from patients treated at our institution, retrospective chart review was performed to describe patient risk factors, treatment approaches, and outcomes associated with C. guilliermondii fungemia. One hundred twelve blood culture isolates of C. guilliermondii were identified, and clinical data were available for 21 fungemic patients. A significant number of isolates (9.8-20.5%) were observed to be non-wild type for various triazoles. All isolates were susceptible to micafungin. A majority (76.2%) of cases of C. guilliermondii fungemia treated at our tertiary care center were hospital-acquired, and two-thirds of patients were immunocompromised at the time of diagnosis. Ten of the 21 patients died within 60 days of fungemia, although mortality was directly or partially attributed to C. guilliermondii fungemia in only four cases (19.0%). Echinocandins may be used for empiric therapy for C. guilliermondii until the results of AST are available. Further research is required to determine appropriate clinical breakpoints for triazoles.

IMPORTANCE

Our study addresses a significant knowledge gap in the clinical management of this non-Candida albicans species. Our retrospective review includes comprehensive AST data for 112 Candida guilliermondii isolates, which is the largest number of isolates reported from the United States to date. Susceptibility data are supplemented by clinical outcomes, where isolates were identified for patients treated at Mayo Clinic. Key findings from our study include the observation that a notable proportion of C. guilliermondii isolates exhibit non-wild-type profiles for various triazoles. Importantly, all isolates remained susceptible to echinocandins, suggesting their efficacy as first-line therapy in the absence of timely susceptibility results. Furthermore, our study highlights the high mortality associated with C. guilliermondii fungemia in immunocompromised patients, emphasizing the urgent need for optimized treatment strategies.

Candida auris: Epidemiology Update and a Review of Strategies to Prevent Spread

Candida auris (C. auris) has emerged as a fungal pathogen with great propensity to spread rapidly on a global scale. C. auris infections have also caused significant morbidity and mortality. Strategies to prevent spread and outbreaks are critical. In this review, an update on the epidemiology of C. auris and a discussion of strategies to combat the spread of C. auris are presented. Future directions are also discussed.

Minding the gap: How transplant infectious disease can help close the organ donation gap

This paper is an educationally focused article discussing how transplant infectious diseases (TID) providers balance the risks of accepting or rejecting an organ and have pushed barriers in organ transplantation. We emphasize the role TID providers play in the transplantation process as critical players on the transplant team. We discuss various donor-derived infections that were previously deemed unacceptable for donation due to concerns for transmission. Advances in medical knowledge have changed some of these situations. We discuss the critical role TID providers have in closing the gap between the thousands of patients on organ waitlists and the organ deficit faced each day. We believe TID providers have a unique opportunity to expand the donor pool by increasing education, expanding acceptable organ definitions, and expanding the boundaries of what we can do with potentially transmissible infections in organ transplantation.

Global research trends and hotspots on human intestinal fungi and health: a bibliometric visualization study

Background

This article employs bibliometric methods and visual maps to delineate the research background, collaborative relationships, hotspots, and trends in the study of gut fungi in human diseases and health.

Methods

Publications related to human gut fungi were retrieved from the Web of Science Core Collection. VOSviewer, CiteSpace, R software and Microsoft Excel were employed to generate visual representations illustrating the contributions made by countries/regions, authors, organizations, and journals. Employing VOSviewer and CiteSpace, we conducted a comprehensive analysis of the retrieved publications, revealing underlying tendencies, research hotspots, and intricate knowledge networks.

Results

This study analyzed a total of 3,954 publications. The United States ranks first in the number of published papers and has the highest number of citations and h-index. Mostafa S Elshahed is the most prolific author. The University of California System is the institution that published the most papers. Frontiers In Microbiology is the journal with the largest number of publications. Three frequently co-cited references have experienced a citation burst lasting until 2024.

Conclusion

Advancements in sequencing technologies have intensified research into human gut fungi and their health implications, shifting the research focus from gut fungal infections towards microbiome science. Inflammatory bowel diseases and Candida albicans have emerged as pivotal areas of interest in this endeavor. Through this study, we have gained a deeper insight into global trends and frontier hotspots within this field, thereby enhancing our understanding of the intricate relationship between gut fungi and human health.

Unveiling the antifungal mechanisms of CTP, a new copper(II)-theophylline/1,10-phenanthroline complex, on drug-resistant non-albicans Candida species

Candida species undeniably rank as the most prevalent opportunistic human fungal pathogens worldwide, with Candida albicans as the predominant representative. However, the emergence of non-albicans Candida species (NACs) has marked a significant shift, accompanied by rising incidence rates and concerning trends of antifungal resistance. The search for new strategies to combat antifungal-resistant Candida strains is of paramount importance. Recently, our research group reported the anti-Candida activity of a coordination compound containing copper(II) complexed with theophylline (theo) and 1,10-phenanthroline (phen), known as "CTP" - Cu(theo)2phen(H2O).5H2O. In the present work, we investigated the mechanisms of action of CTP against six medically relevant, antifungal-resistant NACs, including C. auris, C. glabrata, C. haemulonii, C. krusei, C. parapsilosis and C. tropicalis. CTP demonstrated significant efficacy in inhibiting mitochondrial dehydrogenases, leading to heightened intracellular reactive oxygen species production. CTP treatment resulted in substantial damage to the plasma membrane, as evidenced by the passive incorporation of propidium iodide, and induced DNA fragmentation as revealed by the TUNEL assay. Scanning electron microscopy images of post-CTP treatment NACs further illustrated profound alterations in the fungal surface morphology, including invaginations, cavitations and lysis. These surface modifications significantly impacted the ability of Candida cells to adhere to a polystyrene surface and to form robust biofilm structures. Moreover, CTP was effective in disassembling mature biofilms formed by these NACs. In conclusion, CTP represents a promising avenue for the development of novel antifungals with innovative mechanisms of action against clinically relevant NACs that are resistant to antifungals commonly used in clinical settings.

The Expanding Mycovirome of Aspergilli

Mycoviruses are viruses that infect fungi and are widespread across all major fungal taxa, exhibiting great biological diversity. Since their discovery in the 1960s, researchers have observed a myriad of fungal phenotypes altered due to mycoviral infection. In this review, we examine the nuanced world of mycoviruses in the context of the medically and agriculturally important fungal genus, Aspergillus. The advent of RNA sequencing has revealed a previous underestimate of viral prevalence in fungi, in particular linear single-stranded RNA viruses, and here we outline the diverse viral families known to date that contain mycoviruses infecting Aspergillus. Furthermore, we describe these novel mycoviruses, highlighting those with peculiar genome structures, such as a split RNA dependent RNA polymerase gene. Next, we delineate notable mycovirus-mediated phenotypes in Aspergillus, in particular reporting on observations of mycoviruses that affect their fungal host's virulence and explore how this may relate to virus-mediated decreased stress tolerance. Furthermore, mycovirus effects on microbial competition and antifungal resistance are discussed. The factors that influence the manifestation of these phenotypes, such as temperature, fungal life stage, and infection with multiple viruses, among others, are also evaluated. In addition, we attempt to elucidate the molecular mechanisms that underpin these phenotypes, examining how mycoviruses can be targets, triggers, and even suppressors of RNA silencing and how this can affect fungal gene expression and phenotypes. Finally, we highlight the potential therapeutic applications of mycoviruses and how, in an approach analogous to bacteriophage therapy, their ability to produce hypovirulence in Aspergillus might be used to attenuate invasive aspergillosis infections in humans.

Inhibition of Development and Metabolism of Dual-Species Biofilms of Candida albicans and Candida krusei (Pichia kudriavzevii) by Organoselenium Compounds

Although Candida albicans is the most frequently identified Candida species in clinical settings, a significant number of infections related to the non-albicans Candida (NAC) species, Candida krusei, has been reported. Both species are able to produce biofilms and have been an important resistance-related factor to antimicrobial resistance. In addition, the microbial relationship is common in the human body, contributing to the formation of polymicrobial biofilms. Considering the great number of reports showing the increase in cases of resistance to the available antifungal drugs, the development of new and effective antifungal agents is critical. The inhibitory effect of Organoselenium Compounds (OCs) on the development of Candida albicans and Candida krusei was recently demonstrated, supporting the potential of these compounds as efficient antifungal drugs. In addition, OCs were able to reduce the viability and the development of biofilms, a very important step in colonization and infection caused by fungi. Thus, the objective of this study was to investigate the effect of the Organoselenium Compounds (p-MeOPhSe)2, (PhSe)2, and (p-Cl-PhSe)2 on the development of dual-species biofilms of Candida albicans and Candida krusei produced using either RPMI-1640 or Sabouraud Dextrose Broth (SDB) media. The development of dual-species biofilms was evaluated by the determination of both metabolic activity, using a metabolic assay based on the reduction of XTT (2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide sodium salt) assay and identification of either Candida albicans and Candida krusei on CHROMagar Candida medium. Biofilm formation using RPMI-1640 was inhibited in 90, 55, and 20% by 30 µM (p-MeOPhSe)2, (PhSe)2, and (p-Cl-PhSe)2, respectively. However, biofilms produced using SDB presented an inhibition of 62, 30 and 15% in the presence of 30 µM (p-MeOPhSe)2, (PhSe)2, and (p-Cl-PhSe)2, respectively. The metabolic activity of 24 h biofilms was inhibited by 35, 30 and 20% by 30 µM (p-MeOPhSe)2, (PhSe)2, and (p-Cl-PhSe)2, respectively, with RPMI-1640; however, 24 h biofilms formed using SDB were not modified by the OCs. In addition, a great reduction in the number of CFUs of Candida albicans (93%) in biofilms produced using RPMI-1640 in the presence of 30 µM (p-MeOPhSe)2 was observed. However, biofilms formed using SDB and treated with 30 µM (p-MeOPhSe)2 presented a reduction of 97 and 69% in the number of CFUs of Candida albicans and Candida krusei, respectively. These results demonstrated that Organoselenium Compounds, mainly (p-MeOPhSe)2, are able to decrease the metabolic activity of dual-species biofilms by reducing both Candida albicans and Candida krusei cell number during biofilm formation using either RPMI-1640 or SDB. Taken together, these results demonstrated the potential of the OCs to inhibit the development of dual-species biofilms of Candida albicans and Candida krusei.

Rare case of aspergillosis with solitary renal involvement: micro-fungus ball in graft kidney

Kidney transplant recipients are at an increased risk of various infections due to immunosuppressive medications. Among them, fungal infections are associated with high mortality and morbidity. This report presents the case of a 54-year-old kidney-transplant recipient who was diagnosed with aspergillosis with solitary renal involvement. He was diagnosed by kidney biopsy with the micro-fungus ball. In the biopsy sample, consisting mostly of the medulla, a small focus consisting of an aggregate of fungal microorganisms was identified. The micro-fungus ball, which was also present in serial sections, was characterized by slight pigmentation and septate hyphae with acute angle branching, highlighted by the silver stains. The patient was examined for invasive fungal infection. In CT scans, there were no signs of invasive fungal infection. Due to the unexpected kidney biopsy finding, the patient underwent a repeat allograft biopsy from which a culture was sent. Aspergillus fumigatus complex was detected in tissue fungal culture of this repeat biopsy. The patient was started on voriconazole treatment and was successfully treated. It should be kept in mind that fungal infections with isolated subtle renal involvement may be possible in KTR under immunosuppressive treatment without an obvious fungal focus being demonstrated by imaging methods.

A novel procedure for the quantification of antifungal activity against filamentous fungi, mycelial invasion distance (MID) method

A novel method for the quantification of antifungal activity of fungicides and painted surfaces, mycelial invasion distance (MID) method, was developed and applied to the quantification of activities of parabens and an antifungal paint. In this method, the MID of aerial mycelia on a test paper or a panel placed on a nutrient agar plate was measured with a stereoscopic microscope and a micro-ruler. The antifungal activities of the parabens and painted surfaces were expressed as the MID. The higher the hydrophobicity of parabens, the longer the MID, that is the lower the antifungal activity, were observed. Conversely, relatively polar parabens, such as methyl and ethyl parabens, exhibited stronger antifungal activity, that is shorter MID. The most hydrophobic paraben, benzyl paraben, showed the weakest antifungal activity. Furthermore, it was confirmed that the MID method was effective for the evaluation of the painted surfaces.

[Diagnostic approaches for invasive mycoses: what's hot?]

Invasive fungal infections are a significant cause of morbidity and mortality in immunocompromised patients. The primary and most frequent pathogens in Europe are Aspergillus and Candida species. However, other representatives such as Mucorales, Trichosporon, and Fusarium species are increasingly being identified. Confirming the diagnosis of an invasive mycosis is challenging; apart from imaging and clinical presentation, essential diagnostic elements include conventional fungal culture, microscopy, antibody/antigen detection tests, and molecular biology.

Epidemiology, clinical characteristics, outcome and biofilm forming properties in candidaemia: A single-centre retrospective 4-year analysis from Hungary

BACKGROUND

Candidaemia is a life-threatening disease that is associated with high mortality, especially in intensive care units (ICUs). The number of comprehensive studies dealing with the epidemiologic characteristics of biofilm-related properties is limited.

OBJECTIVE

This study evaluated the clinical characteristics of candidaemia, to assess the biofilm-forming properties of isolates, and to identify the risk factors of mortality.

PATIENTS AND METHODS

A total of 149 candidaemia episodes from the University of Debrecen, Clinical Centre, between January 2020 and December 2023 were investigated retrospectively. The susceptibility of Candida isolates to fluconazole, amphotericin B, anidulafungin, caspofungin, and micafungin was evaluated and compared to the susceptibility of 1-day-old biofilms. Multivariate logistic regression analysis was applied to identify the independent predictors of 30-day mortality rate.

RESULTS

The most common Candida species was Candida albicans (41%), followed by C. parapsilosis (20%), C. glabrata (14%), C. tropicalis (13%), rare Candida species (7%), and C. krusei (5%). Sixty-six percent of Candida isolates were biofilm formers and 44% had high metabolic activity. The 30-day mortality rate was 52%, which was higher in ICUs (65%). The logistic regression analysis revealed several factors significantly influencing mortality including ICU admission (odds ratio [OR] 2.99, 95% confidence interval [CI] 1.17-8.04, p = 0.025), fluconazole treatment (OR 4.12, 95% CI 1.62-11.42, p = .004), and pneumonia (OR 0.261, 95% CI 0.1-0.67, p = .006).

CONCLUSIONS

This comprehensive analysis supports the better characterisation of candidaemia in healthcare settings, which ultimately may reduce mortality among patients.

Targeting Fks1 proteins for novel antifungal drug discovery

Fungal infections are a major threat to human health. The limited availability of antifungal drugs, the emergence of drug resistance, and a growing susceptible population highlight the critical need for novel antifungal agents. The enzymes involved in fungal cell wall synthesis offer potential targets for antifungal drug development. Recent studies have enhanced our focus on the enzyme Fks1, which synthesizes β-1,3-glucan, a critical component of the cell wall. These studies provide a deeper understanding of Fks1's function in cell wall biosynthesis, pathogenicity, structural biology, evolutionary conservation across fungi, and interaction with current antifungal drugs. Here, we discuss the role of Fks1 in the survival and adaptation of fungi, guided by insights from evolutionary and structural analyses. Furthermore, we delve into the dynamics of Fks1 modulation with novel antifungal strategies and assess its potential as an antifungal drug target.

Invasive candidiasis

Invasive candidiasis is an important fungal disease caused by Candida albicans and, increasingly, non-albicans Candida pathogens. Invasive Candida infections originate most frequently from endogenous human reservoirs and are triggered by impaired host defences. Signs and symptoms of invasive candidiasis are non-specific; candidaemia is the most diagnosed manifestation, with disseminated candidiasis affecting single or multiple organs. Diagnosis poses many challenges, and conventional culture techniques are frequently supplemented by non-culture-based assays. The attributable mortality from candidaemia and disseminated infections is ~30%. Fluconazole resistance is a concern for Nakaseomyces glabratus, Candida parapsilosis, and Candida auris and less so in Candida tropicalis infection; acquired echinocandin resistance remains uncommon. The epidemiology of invasive candidiasis varies in different geographical areas and within various patient populations. Risk factors include intensive care unit stay, central venous catheter use, broad-spectrum antibiotics use, abdominal surgery and immune suppression. Early antifungal treatment and central venous catheter removal form the cornerstones to decrease mortality. The landscape of novel therapeutics is growing; however, the application of new drugs requires careful selection of eligible patients as the spectrum of activity is limited to a few fungal species. Unanswered questions and knowledge gaps define future research priorities and a personalized approach to diagnosis and treatment of invasive candidiasis is of paramount importance.

Manganese(II), copper(II) and silver(I) complexes containing 1,10-phenanthroline/1,10-phenanthroline-5,6-dione against Candida species

Background: New chemotherapeutics are urgently required to treat Candida infections caused by drug-resistant strains. Methods: The effects of 16 1,10-phenanthroline (phen)/1,10-phenanthroline-5,6-dione/dicarboxylate complexed with Mn(II), Cu(II) and Ag(I) were evaluated against ten different Candida species. Results: Proliferation of Candida albicans, Candida dubliniensis, Candida famata, Candida glabrata, Candida guilliermondii, Candida kefyr, Candida krusei, Candida lusitaniae, Candida parapsilosis and Candida tropicalis was inhibited by three of six Cu(II) (MICs 1.52-21.55 μM), three of three Ag(I) (MICs 0.11-12.74 μM) and seven of seven Mn(II) (MICs 0.40-38.06 μM) complexes. Among these [Mn2(oda)(phen)4(H2O)2][Mn2(oda)(phen)4(oda)2].4H2O, where oda = octanedioic acid, exhibited effective growth inhibition (MICs 0.4-3.25 μM), favorable activity indexes, low toxicity against Vero cells and good/excellent selectivity indexes (46.88-375). Conclusion: [Mn2(oda)(phen)4(H2O)2][Mn2(oda)(phen)4(oda)2].4H2O represents a promising chemotherapeutic option for emerging, medically relevant and drug-resistant Candida species.

Spectrum and management of rare Candida/yeast infections in Kuwait in the Middle East

Invasive fungal infections (IFIs) are associated with high mortality rates and mostly affect patients with compromised immunity. The incidence of IFIs is increasing worldwide with the expanding population of susceptible patients. Candida and other yeast infections represent a major component of IFIs. Rare Candida/yeast infections have also increased in recent years and pose considerable diagnostic and management challenges as they are not easily recognized by routine phenotypic characteristic-based diagnostic methods and/or by the automated yeast identification systems. Rare Candida/yeasts also exhibit reduced susceptibility to antifungal drugs making proper management of invasive infections challenging. Here, we review the diagnosis and management of 60 cases of rare Candida/yeast IFIs described so far in Kuwait, an Arabian Gulf country in the Middle East. Interestingly, majority (34 of 60, 56.7%) of these rare Candida/yeast invasive infections occurred among neonates or premature, very-low-birth-weight neonates, usually following prior bacteremia episodes. The clinical details, treatment given, and outcome were available for 28 of 34 neonates. The crude mortality rate among these neonates was 32.2% as 19 of 28 (67.8%) survived the infection and were discharged in healthy condition, likely due to accurate diagnosis and frequent use of combination therapy. Physicians treating patients with extended stay under intensive care, on mechanical ventilation, receiving broad spectrum antibiotics and with gastrointestinal surgery/complications should proactively investigate IFIs. Timely diagnosis and early antifungal treatment are essential to decrease mortality. Understanding the epidemiology and spectrum of rare Candida/yeast invasive infections in different geographical regions, their susceptibility profiles and management will help to devise novel diagnostic and treatment approaches and formulate guidelines for improved patient outcome.