The Changing Epidemiology of Invasive Fungal Infections

Metabolic homeostasis in fungal infections from the perspective of pathogens, immune cells, and whole-body systems

SUMMARYThe ability to overcome metabolic stress is a major determinant of outcomes during infections. Pathogens face nutrient and oxygen deprivation in host niches and during their encounter with immune cells. Immune cells require metabolic adaptations for producing antimicrobial compounds and mounting antifungal inflammation. Infection also triggers systemic changes in organ metabolism and energy expenditure that range from an enhanced metabolism to produce energy for a robust immune response to reduced metabolism as infection progresses, which coincides with immune and organ dysfunction. Competition for energy and nutrients between hosts and pathogens means that successful survival and recovery from an infection require a balance between elimination of the pathogen by the immune systems (resistance), and doing so with minimal damage to host tissues and organs (tolerance). Here, we discuss our current knowledge of pathogen, immune cell and systemic metabolism in fungal infections, and the impact of metabolic disorders, such as obesity and diabetes. We put forward the idea that, while our knowledge of the use of metabolic regulation for fungal proliferation and antifungal immune responses (i.e., resistance) has been growing over the years, we also need to study the metabolic mechanisms that control tolerance of fungal pathogens. A comprehensive understanding of how to balance resistance and tolerance by metabolic interventions may provide insights into therapeutic strategies that could be used adjunctly with antifungal drugs to improve patient outcomes.

Use of echinocandin outpatient parenteral antimicrobial therapy for the treatment of infection caused by Candida spp.: utilization, outcomes and impact of a change to weekly dosing

BACKGROUND

Outpatient parenteral antimicrobial therapy (OPAT) can deliver extended parenteral treatment of fungal infections in an ambulatory setting, whilst minimizing treatment burden and cost. The extended dosing interval of rezafungin may potentiate the benefits of OPAT.

METHODS

This retrospective cohort study includes all adult patients who received echinocandin therapy in a large OPAT programme between 2012 and 2022. Patient characteristics, treatment and outcomes were studied. Data were analysed to determine the effects of replacing daily dosing with weekly dosing of echinocandin.

RESULTS

Across the study period, 11% (44/386) of all patients in our Health Service treated with ≥7 days of echinocandin were managed via OPAT. All were Candida and related 'yeast-like' species infections. Nakaseomyces glabrata (20/41; 49%) was the most common pathogen, fungaemia the most common presentation (17/41; 41%) and azole resistance the most frequent indication for echinocandin use (21/41; 51%).In total, 633 days of echinocandin were administered as OPAT. Thirteen patients (13/41; 32%) received concurrent parenteral antibacterials. Treatment success was achieved in 30/41 (73%) patients. If daily echinocandin dosing was replaced with weekly dosing, a potential 52% (633 to 326) reduction in the total number of treatments (for any therapy) delivered by the OPAT team is possible. The ongoing need for daily antibacterial administration mitigated the benefit in some of this cohort.

CONCLUSIONS

Echinocandin therapy can be safely delivered via OPAT with outcomes equivalent to bed-based care. The extended dosing interval of rezafungin will allow for a substantial reduction in the number of treatments required across the patient cohort.

Successful treatment of mixed pulmonary Aspergillus and Mucor infection using intrabronchial amphotericin B infusion: a case report and literature review

BACKGROUND

Reports of pulmonary aspergillosis and mucormycosis co-infections are rare; thus, limited guidance is available on early diagnosis and treatment. We present a case of mixed pulmonary Aspergillus and Mucor infection and review the literature regarding this co-infection. The diagnosis and treatment methods are summarized to improve clinicians' understanding of the disease and to facilitate early diagnosis and treatment.

CASE PRESENTATION

A 60-year-old male farmer with poorly controlled diabetes mellitus was admitted to hospital with a fever of unknown origin that had been present for 15 days and pulmonary aspergillosis complicated by Mucor spp.

INFECTION

Because multiple lobes were involved, the infection worsened despite surgical resection and antifungal therapy. Finally, we treated this patient with a bronchoscopic infusion of amphotericin B. After four courses of bronchoscopic amphotericin B infusion, we observed rapid clinical improvement and subsequent resolution of pulmonary infiltrates.

CONCLUSION

Our case highlights the use of bronchoscopy in the successful clinical treatment of invasive fungal diseases of the lung.

Paving the way for affordable and equitable liposomal amphotericin B access worldwide

Amphotericin B has long been crucial for treating many serious infectious diseases, such as invasive fungal infections and visceral leishmaniasis, particularly for patients who are immunocompromised, including those with advanced HIV infection. The conventional amphotericin B deoxycholate formulation has largely been replaced in high-income countries with liposomal amphotericin B (LAmB), which has many advantages, including lower rates of adverse events, such as nephrotoxicity and anaemia. Despite an evident need for LAmB in low-income and middle-income countries, where mortality from invasive fungal infections is still substantial, many low-income and middle-income countries still often use the amphotericin B deoxycholate formulation because of a small number of generic formulations and the high price of the originator LAmB. The pricing of LAmB is also highly variable between countries. Overcoming supply barriers through the availability of additional quality-assured, generic formulations of LAmB at accessible prices would substantially facilitate equitable access and have a substantial effect on mortality attributable to deadly fungal infections.

Exploring the potential of chitin and chitosan in nanobiocomposites for fungal immunological detection and antifungal action

Chitin is a polymer of N-acetylglucosamine and an essential component of the fungal cell wall. Chitosan is the deacetylated form of chitin and is also important for maintaining the integrity of this structure. Both polysaccharides are widely distributed in nature and have been shown to have a variety of applications in biomedicine, including their potential in immune sensing and as potential antifungal agents. In addition, chitin has been reported to play an important role in the pathogen-host interaction, involving innate and adaptive immune responses. This paper will explore the role of chitin and chitosan when incorporated into nanobiocomposites to improve their efficacy in detecting fungi of medical interest and inhibiting their growth. Potential applications in diagnostic and therapeutic medicine will be discussed, highlighting their promise in the development of more sensitive and effective tools for the early diagnosis of fungal infections. This review aims to highlight the importance of the convergence of nanotechnology and biology in addressing public health challenges.

Potential antifungal applications of heterometallic silica nanohybrids: A synergistic activity

An estimated 1.7 million fatalities and 150 million cases worldwide are attributed to fungal infections annually, that are in rise due to immunocompromised patient population. The challenges posed by traditional treatments can be addressed with the help of nanotechnology advancements. In this study, Co, Cu, and Ag-were doped into silica nanoparticles. Then the synthesized monometallic silica nanohybrids were combined to formulate heterometallic silica nanohybrids, characterized structurally and morphologically, compared, and evaluated for antifungal activity based on their individual and synergistic activity. The antifungal assays were conducted by using ATCC cultures of Candida albicans and QC samples of Trichophyton rubrum, Microsporum gypseum, and Aspergillus niger. The MIC (ranging from 49.00 to 1560.00 μg/mL), MFC (ranging from 197.00 to 3125.00 μg/mL), IC50 values (ranging from 31.10 to 400.80 μg/mL), and FICI of nanohybrids were determined and compared. Moreover, well diffusion assay was performed. ABTS assay and DPPH assay were conducted to investigate the radical scavenging activity (RSA) of nanohybrids. SEM analysis clearly evidenced the structural deformations of each fungal cells and spores due to the treatment with trimetallic nanohybrid. According to the results, the trimetallic silica nanohybrids exhibited the most powerful synergistic RSA and the most effective antifungal activity, compared to the bimetallic silica nanohybrids.

Revolutionizing treatment for topical fungal infections: evaluating penetration-enhancer-containing vesicles as a fluconazole delivery system: Ex-vivo and in-vivo dermal testing

Fungal infections pose a significant challenge in numerous developing nations and worldwide, necessitating urgent solutions. Oral administration of antifungal medications often leads to severe adverse reactions. Hence, employing topical delivery systems is preferred to ensure efficient dermal delivery of antifungal agents while minimizing side effects. Furthermore, the incorporation of penetration enhancers into nanocarriers loaded with antifungal agents has demonstrated enhanced efficacy in combating mycotic infections. Consequently, ultra-deformable penetration enhancer-containing vesicles (PEVs) were developed to explore this promising approach. In this study, Labrasol® and Transcutol® were used as penetration enhancers in formulating ultra-deformable PEVs containing the antifungal agent Fluconazole (FCZ). The PEVs underwent comprehensive characterization, including measurements of particle size (PS), charge, and entrapment efficiency (EE%). The results revealed that the size of tested PEVs ranged from 100 to 762 nm. All particles exhibited a negative charge, with a minimum zeta potential (ZP) of -38.26 mV, and an intermediate entrapment efficiency (EE%) that reached approximately 40%w/w. Ex-vivo studies demonstrated the ability of PEVs to deliver FCZ to the dermis while minimizing transdermal delivery. The selected formula was tested in-vivo using candidiasis-induced rat model and showed a superiority in its antifungal effect against Candida Albicans compared to the drug control. Stability studies were executed for the selected formula, and revealed good stability shown by the insignificant change in the PS, ZP& EE% over a six-month period.

Tackling multi-drug resistant fungi by efflux pump inhibitors

The emergence of multidrug-resistant fungi is of grave concern, and its infections are responsible for significant deaths among immunocompromised patients. The treatment of fungal infections primarily relies on a clinical class of antibiotics, including azoles, polyenes, echinocandins, polyketides, and a nucleotide analogue. However, the incidence of fungal infections is increasing as the treatment for human and plant fungal infections overlaps with antifungal drugs. The need for new antifungal agents acting on different targets than known targets is undeniable. Also, the pace at which loss of fungal susceptibility to antibiotics cannot be undermined. There are several modes by which fungi can develop resistance to antibiotics, including reduced drug uptake, drug target alteration, and a reduction in the cellular concentration of the drug due to active extrusions and biofilm formation. The efflux pump's overexpression in the fungi primarily reduced the antibiotic's concentration to a sub-lethal concentration, thus responsible for developing resistant fungus strains. Several strategies are used to check antibiotic resistance in multi-drug resistant fungi, including synthesizing antibiotic analogs and giving antibiotics in combination therapies. Among them, the efflux pump protein inhibitors are considered potential adjuvants to antibiotics and can block the efflux of antibiotics by inhibiting efflux pump protein transporters. Moreover, it can sensitize the antifungal drugs to multi-drug resistant fungi with overexpressed efflux pump proteins. This review discusses the natural lead molecules, repurposable drugs, and formulation strategies to overcome the efflux pump activity in the fungi.

Invasive fungal rhinosinusitis: current evidence and research opportunities

PURPOSE OF REVIEW

To summarize the evidence surrounding diagnosis, treatment, prognosis, and surveillance of patients with acute invasive fungal sinusitis (AIFS) and discuss future research needs.

RECENT FINDINGS

New risk factors for AIFS such as COVID have been identified, and a new prognostic staging system has been developed.

SUMMARY

Most patients who develop AIFS are immunocompromised, with the majority having a history of diabetes or a hematologic malignancy. Unfortunately, there are not any highly sensitive and specific diagnostic tools. Therefore, a combination of signs and symptoms, imaging, endoscopy, biopsy, and labs should be used to diagnosis AIFS. Although surgery and systemic antifungals are known to improve outcomes, there is limited data on time to intervention, duration of antifungals, and surveillance patterns. There is also limited information on factors that can predict outcomes in AIFS patients. However, sensory/perceptual changes, prolonged neutropenia duration, and comorbidity burden may be associated with a poor prognosis.

Compilation of regulations and procedures for monitoring filamentous fungi in hospital environments

Air and surfaces in the hospital environment are a potential source of exposure to filamentous fungi (FF) that could cause invasive fungal diseases (IFD) in severely immunocompromised patients. The prevalent FF in IFD are species from the genera Aspergillus, Fusarium, Scedosporium, and those within the order Mucorales. We have compiled regulations and described the procedures used in the clinical mycology laboratory to assess the presence of FF in areas at risk for the development of IFD. The infection control committees of each establishment implement hospital policies to regulate and control processes aimed at preventing infections. Fungal load monitoring is an important step in this process to validate air quality in order to ensure a clean and protected environment for severely immunocompromised patients.

Candida glabrata (Nakaseomyces glabrata): A systematic review of clinical and microbiological data from 2011 to 2021 to inform the World Health Organization Fungal Priority Pathogens List

Recognising the growing global burden of fungal infections, the World Health Organization (WHO) established an advisory group consisting of experts in fungal diseases to develop a Fungal Priority Pathogen List. Pathogens were ranked based on their research and development needs and perceived public health importance using a series of global surveys and pathogen characteristics derived from systematic reviews. This systematic review evaluates the features and global impact of invasive disease caused by Candida glabrata (Nakaseomyces glabrata). PubMed and Web of Science were searched for studies reporting on mortality, morbidity (hospitalization and disability), drug resistance (including isolates from sterile and non-sterile sites, since these reflect the same organisms causing invasive infections), preventability, yearly incidence, diagnostics, treatability, and distribution/emergence in the last 10 years. Candida glabrata (N. glabrata) causes difficult-to-treat invasive infections, particularly in patients with underlying conditions such as immunodeficiency, diabetes, or those who have received broad-spectrum antibiotics or chemotherapy. Beyond standard infection prevention and control measures, no specific preventative measures have been described. We found that infection is associated with high mortality rates and that there is a lack of data on complications and sequelae. Resistance to azoles is common and well described in echinocandins-in both cases, the resistance rates are increasing. Candida glabrata remains mostly susceptible to amphotericin and flucytosine. However, the incidence of the disease is increasing, both at the population level and as a proportion of all invasive yeast infections, and the increases appear related to the use of antifungal agents.

Macrophage-derived CD36 + exosome subpopulations as novel biomarkers of Candida albicans infection

Invasive candidiasis (IC) is a notable healthcare-associated fungal infection, characterized by high morbidity, mortality, and substantial treatment costs. Candida albicans emerges as a principal pathogen in this context. Recent academic advancements have shed light on the critical role of exosomes in key biological processes, such as immune responses and antigen presentation. This burgeoning body of research underscores the potential of exosomes in the realm of medical diagnostics and therapeutics, particularly in relation to fungal infections like IC. The exploration of exosomal functions in the pathophysiology of IC not only enhances our understanding of the disease but also opens new avenues for innovative therapeutic interventions. In this investigation, we focus on exosomes (Exos) secreted by macrophages, both uninfected and those infected with C. albicans. Our objective is to extract and analyze these exosomes, delving into the nuances of their protein compositions and subgroups. To achieve this, we employ an innovative technique known as Proximity Barcoding Assay (PBA). This methodology is pivotal in our quest to identify novel biological targets, which could significantly enhance the diagnostic and therapeutic approaches for C. albicans infection. The comparative analysis of exosomal contents from these two distinct cellular states promises to yield insightful data, potentially leading to breakthroughs in understanding and treating this invasive fungal infection. In our study, we analyzed differentially expressed proteins in exosomes from macrophages and C. albicans -infected macrophages, focusing on proteins such as ACE2, CD36, CAV1, LAMP2, CD27, and MPO. We also examined exosome subpopulations, finding a dominant expression of MPO in the most prevalent subgroup, and a distinct expression of CD36 in cluster14. These findings are crucial for understanding the host response to C. albicans and may inform targeted diagnostic and therapeutic approaches. Our study leads us to infer that MPO and CD36 proteins may play roles in the immune escape mechanisms of C. albicans. Additionally, the CD36 exosome subpopulations, identified through our analysis, could serve as potential biomarkers and therapeutic targets for C. albicans infection. This insight opens new avenues for understanding the infection's pathology and developing targeted treatments.

Bisphosphonates synergistically enhance the antifungal activity of azoles in dermatophytes and other pathogenic molds

Superficial infections of the skin, hair, and nails by fungal dermatophytes are the most prevalent of human mycoses, and many infections are refractory to treatment. As current treatment options are limited, recent research has explored drug synergy with azoles for dermatophytoses. Bisphosphonates, which are approved to treat osteoporosis, can synergistically enhance the activity of azoles in diverse yeast pathogens but their activity has not been explored in dermatophytes or other molds. Market bisphosphonates risedronate, alendronate, and zoledronate (ZOL) were evaluated for antifungal efficacy and synergy with three azole antifungals: fluconazole (FLC), itraconazole (ITR), and ketoconazole (KET). ZOL was the most active bisphosphonate tested, displaying moderate activity against nine dermatophyte species (MIC range 64-256 µg/mL), and was synergistic with KET in eight of these species. ZOL was also able to synergistically improve the anti-biofilm activity of KET and combining KET and ZOL prevented the development of antifungal resistance. Rescue assays in Trichophyton rubrum revealed that the inhibitory effects of ZOL alone and in combination with KET were due to the inhibition of squalene synthesis. Fluorescence microscopy using membrane- and ROS-sensitive probes demonstrated that ZOL and KET:ZOL compromised membrane structure and induced oxidative stress. Antifungal activity and synergy between bisphosphonates and azoles were also observed in other clinically relevant molds, including species of Aspergillus and Mucor. These findings indicate that repurposing bisphosphonates as antifungals is a promising strategy for revitalising certain azoles as topical antifungals, and that this combination could be fast-tracked for investigation in clinical trials.

IMPORTANCE

Fungal infections of the skin, hair, and nails, generally grouped together as "tineas" are the most prevalent infectious diseases globally. These infections, caused by fungal species known as dermatophytes, are generally superficial, but can in some cases become aggressive. They are also notoriously difficult to resolve, with few effective treatments and rising levels of drug resistance. Here, we report a potential new treatment that combines azole antifungals with bisphosphonates. Bisphosphonates are approved for the treatment of low bone density diseases, and in fungi they inhibit the biosynthesis of the cell membrane, which is also the target of azoles. Combinations were synergistic across the dermatophyte species and prevented the development of resistance. We extended the study to molds that cause invasive disease, finding synergy in some problematic species. We suggest bisphosphonates could be repurposed as synergents for tinea treatment, and that this combination could be fast-tracked for use in clinical therapy.

Clinical and epidemiological aspects of Candida yeast infections and rational use of antifungals

Aim: The objective of this study was to evaluate the clinical and epidemiological aspects of Candida infections. Methods: The study relied on the analysis of electronic medical records. Results: Among 183 patients with positive fungal infections, 57 were from the community and 126 from hospitals. Females predominated in both groups (82.4% in the community, 54.7% in hospitals). Non-albicans Candida spp. accounted for 62.8% of cases. Antifungal therapy was prescribed for 67 patients, with a 55.6% mortality rate. Conclusion: The increasing prevalence of non-albicans Candida species highlights the need for better candidiasis monitoring and control, especially concerning antifungal use amidst rising antimicrobial resistance, particularly in empirical therapy scenarios.

A Seminested PCR Method for the Diagnosis of Invasive Fungal Infections in Combat Injured

Background

Among combat injured, invasive fungal infections (IFIs) result in significant morbidity. Cultures and histopathology are the primary diagnostic methods for IFIs, but they have limitations. We previously evaluated a panfungal polymerase chain reaction assay, which was 83% sensitive and 99% specific for angioinvasive IFIs. Here, we evaluated 3 less resource-intensive seminested assays targeting clinically relevant fungi in the order Mucorales and genera Aspergillus and Fusarium.

Methods

Formalin-fixed paraffin-embedded tissue specimens from a multicenter trauma IFI cohort (2009-2014) were used. Cases were US military personnel injured in Afghanistan with histopathologic IFI evidence. Controls were patients with similar injury patterns and no laboratory IFI evidence (negative culture and histopathology). Seminested assays specific to Mucorales (V4/V5 regions of 18S rDNA), Aspergillus (mitochondrial tRNA), and Fusarium (internal transcribed spacer [ITS]/28A regions of DNA) were compared with a panfungal assay amplifying the internal transcribed spacer 2 region of rDNA and to histopathology.

Results

Specimens from 92 injury sites (62 subjects) were compared with control specimens from 117 injuries (101 subjects). We observed substantial agreement between the seminested and panfungal assays overall, especially for the order Mucorales. Moderate agreement was observed at the genus level for Aspergillus and Fusarium. When compared with histopathology, sensitivity and specificity of seminested assays were 67.4% and 96.6%, respectively (sensitivity increased to 91.7% when restricted to sites with angioinvasion).

Conclusions

Prior studies of seminested molecular diagnostics have focused on culture-negative samples from immunocompromised patients. Our findings underscore the utility of the seminested approach in diagnosing soft-tissue IFIs using formalin-fixed paraffin-embedded tissue samples, especially with angioinvasion.

Holotoxin A1 from Apostichopus japonicus inhibited oropharyngeal and intra-abdominal candidiasis by inducing oxidative damage in Candida albicans

BACKGROUND AND PURPOSE

The holotoxin A1, isolated from Apostichopus japonicus, exhibits potent antifungal activities, but the mechanism and efficacy against candidiasis are unclear. In this study we have studied the antifungal effects and mechanism of holotoxin A1 against Candida albicans and in murine oropharyngeal and intra-abdominal candidiasis.

EXPERIMENTAL APPROACH

The antifungal effect of holotoxin A1 against C. albicans was tested in vitro. To explore the antifungal mechanism of holotoxin A1, the transcriptome, ROS levels, and mitochondrial function of C. albicans was evaluated. Effectiveness and systematic toxicity of holotoxin A1 in vivo was assessed in the oropharyngeal and intra-abdominal candidiasis models in mice.

KEY RESULTS

Holotoxin A1 was a potent fungicide against C. albicans SC5314, clinical strains and drug-resistant strains. Holotoxin A1 inhibited oxidative phosphorylation and induced oxidative damage by increasing intracellular accumulation of ROS in C. albicans. Holotoxin A1 induced dysfunction of mitochondria by depolarizing the mitochondrial membrane potential and reducing the production of ATP. Holotoxin A1 directly inhibited the enzymatic activity of mitochondrial complex I and antagonized with the rotenone, an inhibitor of complex I, against C. albicans. Meanwhile, the complex I subunit NDH51 null mutants showed a decreased susceptibility to holotoxin A1. Furthermore, holotoxin A1 significantly reduced fungal burden and infections with no significant systemic toxicity in oropharyngeal and intra-abdominal candidiasis in murine models.

CONCLUSION AND IMPLICATIONS

Holotoxin A1 is a promising candidate for the development of novel antifungal agents against both oropharyngeal and intra-abdominal candidiasis, especially when caused by drug-resistant strains.

The practice and evaluation of antifungal stewardship programs at a tertiary first-class hospital in China

BACKGROUND

The sharp increase in fungal infections, insufficient diagnostic and treatment capabilities for fungal infections, poor prognosis of patients with fungal infections as well as the increasing drug resistance of fungi are serious clinical problems. It is necessary to explore the implementation and evaluation methods of antifungal stewardship (AFS) to promote the standardized use of antifungal drugs.

METHODS

The AFS programme was implemented at a tertiary first-class hospital in China using a plan-do-check-act (PDCA) quality management tool. A baseline investigation was carried out to determine the utilization of antifungal drugs in pilot hospitals, analyse the existing problems and causes, and propose corresponding solutions. The AFS programme was proposed and implemented beginning in 2021, and included various aspects, such as team building, establishment of regulations, information construction, prescription review and professional training. The management effectiveness was recorded from multiple perspectives, such as the consumption of antifungal drugs, the microbial inspection rate of clinical specimens, and the proportion of rational prescriptions. The PDCA management concept was used for continuous improvement to achieve closed-loop management.

RESULTS

In the first year after the implementation of the AFS programme, the consumption cost, use intensity and utilization rate of antifungal drugs decreased significantly (P < 0.01). The proportion of rational antifungal drug prescriptions markedly increased, with the proportion of prescriptions with indications increasing from 86.4% in 2019 to 97.0% in 2022, and the proportion of prescriptions with appropriate usage and dosage increased from 51.9 to 87.1%. In addition, after the implementation of the AFS programme, physicians' awareness of the need to complete microbial examinations improved, and the number of fungal cultures and serological examinations increased substantially. Statistics from drug susceptibility tests revealed a decrease in the resistance rate of Candida to fluconazole.

CONCLUSION

This study indicated that the combination of AFS and the PDCA cycle could effectively reduce antifungal consumption and promote the rational use of antifungal drugs, providing a reference for other health care systems to reduce the overuse of antifungal drugs and delay the progression of fungal resistance.

Humans vs. Fungi: An Overview of Fungal Pathogens against Humans

Human fungal diseases are infections caused by any fungus that invades human tissues, causing superficial, subcutaneous, or systemic diseases. Fungal infections that enter various human tissues and organs pose a significant threat to millions of individuals with weakened immune systems globally. Over recent decades, the reported cases of invasive fungal infections have increased substantially and research progress in this field has also been rapidly boosted. This review provides a comprehensive list of human fungal pathogens extracted from over 850 recent case reports, and a summary of the relevant disease conditions and their origins. Details of 281 human fungal pathogens belonging to 12 classes and 104 genera in the divisions ascomycota, basidiomycota, entomophthoromycota, and mucoromycota are listed. Among these, Aspergillus stands out as the genus with the greatest potential of infecting humans, comprising 16 species known to infect humans. Additionally, three other genera, Curvularia, Exophiala, and Trichophyton, are recognized as significant genera, each comprising 10 or more known human pathogenic species. A phylogenetic analysis based on partial sequences of the 28S nrRNA gene (LSU) of human fungal pathogens was performed to show their phylogenetic relationships and clarify their taxonomies. In addition, this review summarizes the recent advancements in fungal disease diagnosis and therapeutics.

Exploring European Consensus About the Remaining Treatment Challenges and Subsequent Opportunities to Improve the Management of Invasive Fungal Infection (IFI) in the Intensive Care Unit

BACKGROUND

The global prevalence of invasive fungal infections (IFI) is increasing, particularly within Intensive Care Units (ICU), where Candida spp. and Aspergillus spp. represent the most important pathogens. Diagnosis and management of IFIs becomes progressively challenging, with increasing antifungal resistance and the emergence of rare fungal species. Through a consensus survey focused on assessing current views on how IFI should be managed, the aim of this project was to identify challenges around diagnosing and managing IFIs in the ICU. The current status in different countries and perceived challenges to date amongst a multidisciplinary cohort of healthcare professionals involved in the care of IFI in the ICU was assessed.

METHODS

Using a modified Delphi approach, an expert panel developed 44 Likert-scale statements across 6 key domains concerning patient screening and minimal standards for diagnosis of IFIs in ICU; initiation and termination of antifungal treatments and how to minimise their side effects and insights for future research on this topic. These were used to develop an online survey which was distributed on a convenience sampling basis utilising the subscriber list held by an independent provider (M3 Global). This survey was distributed to intensivists, infectious disease specialists, microbiologists and antimicrobial/ICU pharmacists within the UK, Germany, Spain, France and Italy. The threshold for consensus was set at 75%.

RESULTS

A total of 335 responses were received during the five-month collection period. From these, 29/44 (66%) statements attained very high agreement (≥ 90%), 11/44 (25%) high agreement (< 90% and ≥ 75%), and 4/44 (9%) did not meet threshold for consensus (< 75%).

CONCLUSION

The results outline the need for physicians to be aware of the local incidence of IFI and the associated rate of azole resistance in their ICUs. Where high clinical suspicion exists, treatment should start immediately and prior to receiving the results from any diagnostic test. Beta-D-glucan testing should be available to all ICU centres, with results available within 48 h to inform the cessation of empirical antifungal therapy. These consensus statements and proposed measures may guide future areas for further research to optimise the management of IFIs in the ICU.

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.

The value of calcofluor white in the diagnosis of invasive fungal diseases

PURPOSE

To evaluate the value of calcofluor white in the diagnosis of invasive fungal disease (IFD).

METHODS

A total of 84 patients with possible pulmonary fungal infection who underwent bronchoscopy with bronchoalveolar lavage fluid (BALF) were included. All BALF specimens were subjected to Calcofluor white (CFW), potassium hydroxide (KOH) and Gram stains.

RESULTS

CFW has the most sensitivity than KOH and Gram staining. The specificity of CFW was 92.00 %, which was lower than that of Gram staining. The PPVs for CFW, KOH and Gram staining were 94.44 %, 84.62 % and 80.00 % respectively. The NPVs for CFW, KOH and Gram staining was 47.92 %, 32.39 % and 30.38 % respectively. The AUCs of these three methods were 0.748, 0.550 and 0.510 respectively.

CONCLUSION

CFW is superior to KOH and Gram staining in the diagnosis of invasive fungal diseases.

Economic impact of managing invasive mold disease with isavuconazole compared with liposomal amphotericin B followed by posaconazole in Spain

BACKGROUND

Invasive fungal infections (IFI) are associated with significant morbidity and mortality. The objective of this work was to compare the costs per adult patient, associated with intravenous isavuconazole (ISAV) followed by oral ISAV versus the regimen of liposomal amphotericin B followed by posaconazole (L-AMB→POSA) in the treatment of IFI. The comparison was conducted from the perspective of the Spanish National Health System (SNS).

METHODS

As indirect comparisons have demonstrated similar efficacy between the comparators, a cost-minimization approach was taken. Drug acquisition, administration, hospitalization, laboratory tests and adverse events costs were evaluated from SNS perspective. Deterministic and probabilistic sensitivity analyzes were performed.

RESULTS

Total costs per-patient were €24,715.54 with ISAV versus €29,753.53 with L-AMB→POSA, resulting in cost-savings per patient treated with ISAV of €5,037.99 (-16.9%). Treatment costs of IFI remained lower for ISAV than for L-AMB→POSA across all sensitivity analyses (-7,968.89€ to -326.59€), being treatment duration the most influential parameter.

CONCLUSION

According to the present model, the treatment of IFIs with ISAV would generate savings for the SNS compared to L-AMB→POSA. These savings are attributed to the shorter duration of IV treatment, reduced use of healthcare resources and lower costs associated with managing adverse effects when ISAV was employed.

From Synergy to Monotherapy: Discovery of Novel 2,4,6-Trisubstituted Triazine Hydrazone Derivatives with Potent Antifungal Potency In Vitro and In Vivo

Invasive fungal infections pose a serious threat to public health and are associated with high mortality and incidence rates. The development of novel antifungal agents is urgently needed. Based on hit-to-lead optimization, a series of 2,4,6-trisubstituted triazine hydrazone compounds were designed, synthesized, and biological evaluation was performed, leading to the identification of compound 28 with excellent in vitro synergy (FICI range: 0.094-0.38) and improved monotherapy potency against fluconazole-resistant Candida albicans and Candida auris (MIC range: 1.0-16.0 μg/mL). Moreover, 28 exhibited broad-spectrum antifungal activity against multiple pathogenic strains. Furthermore, 28 could inhibit hyphal and biofilm formation, which may be related to its ability to disrupt the fungal cell wall. Additionally, 28 significantly reduced the CFU in a mouse model of disseminated infection with candidiasis at a dose of 10 mg/kg. Overall, the triazine-based hydrazone compound 28 with low cytotoxicity, hemolysis, and favorable ADME/T characteristics represents a promising lead to further investigation.

Biowaiver Monograph for Immediate-Release Solid Oral Dosage Forms: Isavuconazonium Sulfate

A Biopharmaceutics Classification System (BCS)-based biowaiver monograph is presented for isavuconazonium sulfate. A BCS-based biowaiver is a regulatory option to substitute appropriate in vitro data for in vivo bioequivalence studies. Isavuconazonium sulfate is the prodrug of isavuconazole, a broad-spectrum azole antifungal indicated for invasive fungal infections. While the prodrug can be classified as a BCS Class III drug with high solubility but low permeability, the parent drug can be classified as a BCS Class II drug with low solubility but high permeability. Interestingly, the in vivo behavior of both is additive and leads isavuconazonium sulfate to act like a BCS class I drug substance after oral administration. In this work, experimental solubility and dissolution data were evaluated and compared with available literature data to investigate whether it is feasible to approve immediate release solid oral dosage forms containing isavuconazonium sulfate according to official guidance from the FDA, EMA and/or ICH. The risks associated with waiving a prodrug according to the BCS-based biowaiver guidelines are reviewed and discussed, noting that current regulations are quite restrictive on this point. Further, results show high solubility but instability of isavuconazonium sulfate in aqueous media. Although experiments on the dissolution of the capsule contents confirmed 'very rapid' dissolution of the active pharmaceutical ingredient (API) isavuconazonium sulfate, its release from the commercial marketed capsule formulation Cresemba is limited by the choice of capsule shell material, providing an additional impediment to approval of generic versions via the BCS-Biowaiver approach.

In vitro interactions of proton pump inhibitors and azoles against pathogenic fungi

Introduction

Azole resistance has been increasingly reported and become an issue for clinical managements of invasive mycoses. New strategy with combination therapy arises as a valuable and promising alternative option. The aim of the present study is to investigate the in vitro combinational effect of proton pump inhibitors (PPIs) and azoles against pathogenic fungi.

Methods

In vitro interactions of PPIs including omeprazole (OME), lansoprazole (LAN), pantoprazole (PAN), and rabeprazole (RAB), and commonly used azoles including itraconazole (ITC), posaconazole (POS), voriconazole (VRC) and fluconazole (FLC), were investigated via broth microdilution chequerboard procedure adapted from the CLSI M27-A3 and M38-A2. A total of 67 clinically isolated strains, namely 27 strains of Aspergillus spp., 16 strains of Candida spp., and 24 strains of dematiaceous fungi, were studied. C. parapsilosis (ATCC 22019) and A. flavus (ATCC 204304) was included to ensure quality control.

Results

PPIs individually did not exert any significant antifungal activity. The combination of OME with ITC, POS, or VRC showed synergism against 77.6%, 86.6%, and 4% strains of tested pathogenic fungi, respectively, while synergism of OME/FLC was observed in 50% strains of Candida spp. Synergism between PAN and ITC, POS, or VRC was observed against 47.8%, 77.6% and 1.5% strains of tested fungi, respectively, while synergism of PNA/FLC was observed in 50% strains of Candida spp. Synergism of LAN with ITC, POS, or VRC was observed against 86.6%, 86.6%, and 3% of tested strains, respectively, while synergism of LAN/FLC was observed in 31.3% strains of Candida spp. Synergy of the combination of RAB with ITC, POS, or VRC was observed against 25.4%, 64.2%, and 4.5% of tested strains, respectively, while synergism of RAB/FLC was observed in 12.5% of Candida spp.. Among PPIs, synergism was least observed between RAB and triazoles, while among triazoles, synergism was least observed between VRC and PPIs. Among species, synergy was much more frequently observed in Aspergillus spp. and dematiaceous fungi as compared to Candida spp. Antagonism between PPIs with ITC or VRC was occasionally observed in Aspergillus spp. and dematiaceous fungi. It is notable that PPIs combined with azoles showed synergy against azole resistant A. fumigatus, and resulted in category change of susceptibility of ITC and POS against Candida spp.

Discussion

The results suggested that PPIs combined with azoles has the potential to enhance the susceptibilities of azoles against multiple pathogenic fungi and could be a promising strategy to overcome azole resistance issues. However, further investigations are warranted to study the combinational efficacy in more isolates and more species, to investigate the underlying mechanism of interaction and to evaluate the potential for concomitant use of these agents in human.

Native human and mouse skin infection models to study Candida auris-host interactions

The World Health Organization (WHO) declared certain fungal pathogens as global health threats for the next decade. Candida auris (C. auris) is a newly emerging skin-tropic multidrug-resistant fungal pathogen that can cause life-threatening infections of high mortality in hospitals and healthcare settings. Here, we address an unmet need and present novel native ex vivo skin models, thus extending previous C. auris-host interaction studies. We exploit histology and immunofluorescence analysis of ex vivo skin biopsies of human adult and fetal, as well as mouse origin infected with C. auris via distinct routes. We demonstrate that an intact skin barrier efficiently protects from C. auris penetration and invasion. Although C. auris readily grows on native human skin, it can reach deeper layers only upon physical disruption of the barrier by needling or through otherwise damaged skin. By contrast, a barrier disruption is not necessary for C. auris penetration of native mouse skin. Importantly, we show that C. auris undergoes morphogenetic changes upon skin penetration, as it acquires pseudohyphal growth phenotypes in deeper human and mouse dermis. Taken together, this new human and mouse skin model toolset yields new insights into C. auris colonization, adhesion, growth and invasion properties of native versus damaged human skin. The results form a crucial basis for future studies on skin immune defense to colonizing pathogens, and offer new options for testing the action and efficacy of topical antimicrobial compound formulations.

Understanding fluconazole tolerance in Candida albicans: implications for effective treatment of candidiasis and combating invasive fungal infections

OBJECTIVES

Fluconazole (FLC) tolerant phenotypes in Candida species contribute to persistent candidemia and the emergence of FLC resistance. Therefore, making FLC fungicidal and eliminating FLC tolerance are important for treating invasive fungal diseases (IFDs) caused by Candida species. However, the mechanisms of FLC tolerance in Candida species remain to be fully explored.

METHODS

This review discusses the high incidence of FLC tolerance in Candida species and the importance of successfully clearing FLC tolerance in treating candidiasis. We further define and characterize FLC tolerance in C. albicans.

RESULTS

This review identifies global factors affecting FLC tolerance and suggest that FLC tolerance is a strategy of C. albicans response to FLC damage whose mechanism differs from FLC resistance.

CONCLUSIONS

This review highlights the significance of the cell membrane and cell wall integrity in FLC tolerance, guiding approaches to combat IFDs caused by Candida species..

The first established microsatellite markers to distinguish Candida orthopsilosis isolates and detection of a nosocomial outbreak in China

The infection proportion of Candida orthopsilosis, a member of the C. parapsilosis complex, has increased globally in recent years, and nosocomial outbreaks have been reported in several countries. This study aimed to establish microsatellite loci-based typing method that was able to effectively distinguish among C. orthopsilosis isolates. Three reference C. orthopsilosis genome sequences were analyzed to identify repeat loci. DNA sequences containing over eight bi- or more nucleotide repeats were selected. A total of 51 loci were initially identified, and locus-specific primers were designed and tested with 20 epidemiologically unrelated isolates. Four loci with excellent reproducibility, specificity, and resolution for molecular typing purposes were identified, and the combined discriminatory power (DP, based on 20 epidemiologically unrelated isolates) of these four loci was 1.0. Reproducibility was demonstrated by consistently testing three strains each in triplicate, and stability, demonstrated by testing 10 successive passages. Then, we collected 48 C. orthopsilosis non-duplicate clinical isolates from the China Hospital Invasive Fungal Surveillance Net study to compare the DP of the microsatellite-based typing with internal transcribed spacer (ITS) and amplified fragment length polymorphism (AFLP) typing analyses, using ATCC 96139 as a reference strain. These 49 isolates were subdivided into 12 microsatellite types (COMT1-12), six AFLP types, and three ITS types, while all the isolates with the same COMT belonged to consistent AFLP and ITS type, demonstrating the high DP of our microsatellite-type method. According to our results, COMT12 was found to be the predominant type in China, and COMT5 was the second largest and responsible for causing a nosocomial outbreak. This microsatellite-type method is a valuable tool for the differentiation of C. orthopsilosis and could be vital for epidemiological studies to determine strain relatedness and monitor transmission.

Natural Polyketides Act as Promising Antifungal Agents

Invasive fungal infections present a significant risk to human health. The current arsenal of antifungal drugs is hindered by drug resistance, limited antifungal range, inadequate safety profiles, and low oral bioavailability. Consequently, there is an urgent imperative to develop novel antifungal medications for clinical application. This comprehensive review provides a summary of the antifungal properties and mechanisms exhibited by natural polyketides, encompassing macrolide polyethers, polyether polyketides, xanthone polyketides, linear polyketides, hybrid polyketide non-ribosomal peptides, and pyridine derivatives. Investigating natural polyketide compounds and their derivatives has demonstrated their remarkable efficacy and promising clinical application as antifungal agents.

Developing Novel Coumarin-Containing Azoles Antifungal Agents by the Scaffold Merging Strategy for Treating Azole-Resistant Candidiasis

The extensive use of antifungal drugs has resulted in severe drug resistance, making clinical treatment of fungal infections more difficult. Biofilm inhibitors can overcome drug resistance by inhibiting fungal biofilm formation. In this study, some coumarins with antibiofilm activity were merged into CYP51 inhibitors to produce novel molecules possessing potent antiresistance activity. As expected, most compounds exhibited excellent in vitro antifungal activity against pathogenic fungi, especially fluconazole-resistant candidiasis. Then, their mechanism was confirmed by sterol composition analysis and morphological observation. Biofilm inhibition and down-regulation of resistance-related genes were employed to confirm the compounds' antiresistance mechanisms. Significantly, compound A32 demonstrated fungicidal activity against fluconazole-resistant strain 904. Most importantly, compound A32 showed potent in vivo antifungal activity against pathogenic fungi and fluconazole-resistant strains. Preliminary pharmacokinetic and toxicity tests demonstrated that the compounds possessed favorable druggability. Taken together, compound A32 represents a promising lead to develop novel antifungal agents for treating azole-resistant candidiasis.

Six-Year Retrospective Analysis of Epidemiology, Risk Factors, and Antifungal Susceptibilities of Candidiasis from a Tertiary Care Hospital in South China

Candidiasis is a life-threatening disease that increases mortality in critically ill patients. However, such epidemiological data are still lacking in underdeveloped regions of China. A retrospective analysis (2016 to 2021) was conducted in Meizhou People's Hospital, China to study the burden of candidiasis, particularly candidemia, and antifungal susceptibilities of the species among hospitalized patients. Of the 7,864 candidiasis cases, 461 (5.86%) were candidemia cases. Candida albicans (64.25%) was the most identified species, followed by C. tropicalis (12.61%), C. glabrata (10.79%), and C. parapsilosis (9.79%). In non-C. albicans (NCA) candidemia cases, the number of C. glabrata cases was higher (102/461, 22.37%) than C. tropicalis (64/461, 14.04%). Gastrointestinal pathology, respiratory dysfunctions, septic shock, and malignancies were common underlying comorbidities, respectively. A central venous catheter was an independent risk factor for both C. albicans and NCA candidemia. The mortality rate was not statistically significant for either C. albicans or NCA. Amphotericin B and 5-flucytosine were highly effective (98 to 100%), while azoles were least effective (67.74 to 95.66%). Candidemia cases caused by C. tropicalis and C. glabrata had significantly lower azole susceptibility than non-candidemia-causing isolates. This study provides valuable information for prescribers to choose the right empirical therapy, for researchers to explore different resistance mechanisms, and for health care managers to control candidiasis better. IMPORTANCE This study provides important information on the burden of candidiasis, particularly candidemia, and the antifungal susceptibility of Candida species among hospitalized patients in an underdeveloped region of China. First, the finding that azoles were least effective against Candida species causing candidemia is particularly noteworthy, as it suggests the possibility of resistance to this class of antifungal agents. This information can guide the choice of empirical therapy and help in the selection of appropriate antifungal agents for the treatment of candidemia, thereby reducing the risk of resistance development. Second, the study provides important information for researchers to explore different resistance mechanisms in Candida species. Finally, the study has important implications for health care managers in controlling the spread of candidiasis. The high prevalence of candidemia cases in the study highlights the need for appropriate infection control measures to prevent the spread of the disease.

Candida Biofilm Eye Infection: Main Aspects and Advance in Novel Agents as Potential Source of Treatment

Fungi represent a very important cause of microbial eye infections, especially in tropical and developing countries, as they could cause sight-threating disease, such as keratitis and ocular candidiasis, resulting in irreversible vision loss. Candida species are among the most frequent microorganisms associated with fungal infection. Although Candida albicans is still the most frequently detected organism among Candida subspecies, an important increase in non-albicans species has been reported. Mycotic infections often represent an important diagnostic-clinical problem due to the difficulties in performing the diagnosis and a therapeutic problem due to the limited availability of commercial drugs and the difficult penetration of antifungals into ocular tissues. The ability to form biofilms is another feature that makes Candida a dangerous pathogen. In this review, a summary of the state-of-the-art panorama about candida ocular pathology, diagnosis, and treatment has been conducted. Moreover, we also focused on new prospective natural compounds, including nanoparticles, micelles, and nanocarriers, as promising drug delivery systems to better cure ocular fungal and biofilm-related infections. The effect of the drug combination has also been examined from the perspective of increasing efficacy and improving the course of infections caused by Candida which are difficult to fight.

Combining the Peptide RWQWRWQWR and an Ethanolic Extract of Bidens pilosa Enhances the Activity against Sensitive and Resistant Candida albicans and C. auris Strains

The antifungal activity of palindromic peptide RWQWRWQWR and its derivatives was evaluated against clinical isolates of Candida albicans and C. auris. Also, Bidens pilosa ethanolic extracts of leaves and stem were evaluated. Furthermore, combinations of peptide, extract, and/or fluconazole (FLC) were evaluated. The cytotoxicity of peptides and extracts in erythrocytes and fibroblasts was determined. The original palindromic peptide, some derivative peptides, and the ethanolic extract of leaves of B. pilosa exhibited the highest activity in some of the strains evaluated. Synergy was obtained between the peptide and the FLC against C. auris 435. The combination of the extract and the original palindromic peptide against C. albicans SC5314, C. auris 435, and C. auris 537 decreased the minimal inhibitory concentrations (MICs) by a factor of between 4 and 16. These mixtures induced changes in cell morphology, such as deformations on the cell surface. The results suggest that the combination of RWQWRWQWR and B. pilosa extract is an alternative for enhancing antifungal activity and decreasing cytotoxicity and costs and should be considered to be a promising strategy for treating diseases caused by Candida spp.

Challenges in the Management of Invasive Fungal Infections in the Middle East: Expert Opinion to Optimize Management Using a Multidisciplinary Approach

Invasive fungal infection (IFI) is a significant global healthcare concern among critically ill and immunocompromised patients. In Middle Eastern countries, IFI has been steadily increasing among hospitalized patients in the past two decades. Diagnosis of IFI at an early stage is crucial for efficient management. Invasive fungal infection management is complex and requires the involvement of physicians from different specialties. There are several challenges associated with IFI management in the countries in the Middle East. This review aims to understand the key challenges associated with IFI management in the Middle East, encompassing epidemiology, diagnosis, therapeutic options, and optimizing a multidisciplinary approach. In addition, this review aims to incorporate expert opinions from multidisciplinary fields for optimizing IFI management in different Middle Eastern countries by addressing key decision points throughout the patient's journey. Lack of epidemiological data on fungal infections, slow and poorly sensitive conventional culture-based diagnostic tests, limited availability of biomarker testing, lack of awareness of clinical symptoms of the disease, limited knowledge on fungal infections, lack of local practice guidelines, and complicated disease management are the major challenges associated with IFI diagnosis and management in the Middle Eastern countries. Implementation of a multidisciplinary approach, antifungal stewardship, improved knowledge of fungal infections, the use of rapid diagnostic tests, and enhanced epidemiological research are warranted to lower the IFI burden in the Middle East.

Multifactor transcriptional control of alternative oxidase induction integrates diverse environmental inputs to enable fungal virulence

Metabolic flexibility enables fungi to invade challenging host environments. In Candida albicans, a common cause of life-threatening infections in humans, an important contributor to flexibility is alternative oxidase (Aox) activity. Dramatic induction of this activity occurs under respiratory-stress conditions, which impair the classical electron transport chain (ETC). Here, we show that deletion of the inducible AOX2 gene cripples C. albicans virulence in mice by increasing immune recognition. To investigate further, we examined transcriptional regulation of AOX2 in molecular detail under host-relevant, ETC-inhibitory conditions. We found that multiple transcription factors, including Rtg1/Rtg3, Cwt1/Zcf11, and Zcf2, bind and regulate the AOX2 promoter, conferring thousand-fold levels of inducibility to AOX2 in response to distinct environmental stressors. Further dissection of this complex promoter revealed how integration of stimuli ranging from reactive species of oxygen, nitrogen, and sulfur to reduced copper availability is achieved at the transcriptional level to regulate AOX2 induction and enable pathogenesis.

Epidemiological Characteristics, Antifungal Susceptibility, Risk Factors, and Outcomes of Candida Bloodstream Infection: A Ten-Year Surveillance in a Teaching Hospital in China

Background

Candida is one of the most important pathogens of hospital-acquired bloodstream infections. Its morbidity and mortality are still high, which is a serious global public problem.

Purpose

To investigate the strain distribution, drug susceptibility, clinical characteristics of patients, and risk factors affecting the prognosis of Candida bloodstream infection (BSI).

Materials and Methods

We retrospectively collected the clinical data, infection-related indicators, prognosis, strain prevalence and drug susceptibility of 163 patients with Candida BSI in a teaching hospital from January 2012 to December 2022. Univariate and multivariate logistic regression were used to analyze the risk factors affecting the prognosis.

Results

In 163 cases of Candida BSI, Candida albicans accounted for 48.47%, and Candida non-albicans accounted for 51.53%. A total of 163 patients with Candida BSI were mainly distributed in intensive care unit (ICU) and emergency department, accounting for 40.49% and 14.72%, respectively. The resistance rate of Candida albicans to fluconazole, itraconazole and voriconazole was less than 10%, and the sensitivity rate of Candida tropicalis to fluconazole, itraconazole and voriconazole was less than 80%. The mortality rate of 163 patients with Candida BSI was 33.13%, with Candida non-albicans higher than that of Candida albicans (p = 0.04). Multivariate analysis showed that hemodialysis (OR = 0.199, 95% CI: 0.059-0.673, P = 0.009), arteriovenous catheters (OR = 0.344, 95% CI: 0.130-0.913, P = 0.032), elevated neutrophil count (OR = 0.409, 95% CI: 0.194-0.862, P = 0.019) and APACHE II score (OR = 0.848, 95% CI: 0.789~0.911, P < 0.001) were independent risk factors for death in patients with candidemia.

Conclusion

The blood flow infection rate of Candida non-albicans is increasing, and the mortality rate and resistance to antifungal drugs are higher than that of Candida albicans. Hemodialysis, arteriovenous catheters, elevated neutrophil count and APACHE II score were associated with death in patients with Candida BSI.

Invasive Candidiasis in Patients with Solid Tumors: A Single-Center Retrospective Study

Background

Invasive candidiasis (ICs) is one of the common causes of death in patients with solid tumors. However, studies on the clinical characteristics of ICs with solid tumors are limited.

Methods

The purpose of this study was to retrospectively analyse the clinical characteristics, laboratory results and risk factor prediction of inpatients with ICs and solid tumors. We reviewed the clinical data and candida specimen information of hospitalized patients diagnosed with solid tumors combined with ICs at the First Hospital of China Medical University from January 2016 to December 2020. Multivariate logistic regression analysis was used to assess the prognostic factors associated with mortality in these patients.

Results

A total of 243 ICs patients with solid tumors were included in this study. The average ± SD age was 62.8 ± 11.7 (range: 27-93 years old), of which nearly 41% were ≥ 65 years old (99/243, 40.7%), and most were male (162/243, 66.6%). Most patients had malignant tumors of the digestive system. The most common candida was Candida parapsilosis (101/243, 41.5%), followed by Candida guilliermondii (83/243, 34.1%), Candida albicans (32/243, 13.1%), Candida glabrata (17/243, 6.9%), Candida tropicalis (7/243, 2.8%) and Candida krusei (3/243, 1.2%). Multivariate logistic regression analysis showed that the length of stay in the ICU, urinary catheter, total parenteral nutrition, stay in the ICU, renal failure and neutrophil count were prognostic factors related to death.

Conclusion

In this study, based on the clinical data of solid tumor patients with ICs in the past 5 years, the results showed that the length of stay in the ICU, urinary catheter, total parenteral nutrition, stay in the ICU, renal failure and neutrophil count were identified as the main prognostic factors. This study can be used to help clinicians carry out early intervention for high-risk patients.

Cm-p5 Peptide Dimers Inhibit Biofilms of Candida albicans Clinical Isolates, C. parapsilosis and Fluconazole-Resistant Mutants of C. auris

Antimicrobial peptides (AMPs) represent a promising class of therapeutic biomolecules that show antimicrobial activity against a broad range of microorganisms, including life-threatening pathogens. In contrast to classic AMPs with membrane-disrupting activities, new peptides with a specific anti-biofilm effect are gaining in importance since biofilms could be the most important way of life, especially for pathogens, as the interaction with host tissues is crucial for the full development of their virulence in the event of infection. Therefore, in a previous study, two synthetic dimeric derivatives (parallel Dimer 1 and antiparallel Dimer 2) of the AMP Cm-p5 showed specific inhibition of the formation of Candida auris biofilms. Here we show that these derivatives are also dose-dependently effective against de novo biofilms that are formed by the widespread pathogenic yeasts C. albicans and C. parapsilosis. Moreover, the activity of the peptides was demonstrated even against two fluconazole-resistant strains of C. auris.

Phenotypic Array for Identification and Screening of Antifungals against Aspergillus Isolates from Respiratory Infections in KwaZulu Natal, South Africa

The rapid emergence of invasive fungal infections correlates with the increasing population of immunocompromised individuals, with many cases leading to death. The progressive increase in the incidence of Aspergillus isolates is even more severe due to the clinical challenges in treating invasive infections in immunocompromised patients with respiratory conditions. Rapid detection and diagnosis are needed to reduce mortality in individuals with invasive aspergillosis-related infections and thus efficient identification impacts clinical success. The phenotypic array method was compared to conventional morphology and molecular identification on thirty-six Aspergillus species isolated from patients with respiratory infections at the Inkosi Albert Luthuli Hospital in Kwa-Zulu Natal. In addition, an antimicrobial array was also carried out to screen for possible novel antimicrobial compounds for treatment. Although traditional morphological techniques are useful, genetic identification was the most reliable, assigning 26 to Aspergillus fumigatus species, 8 Aspergillus niger, and 2 Aspergillus flavus including cryptic species of A. niger, A. tubingensis and A. welwitschiae. The phenotypic array technique was only able to identify isolates up to the genus level due to a lack of adequate reference clinical species in the database. However, this technique proved crucial in assessing a wide range of possible antimicrobial options after these isolates exhibited some resistance to azoles. Antifungal profiles of the thirty-six isolates on the routine azole voriconazole showed a resistance of 6%, with 61% having moderate susceptibility. All isolates resistant to the salvage therapy drug, posaconazole pose a serious concern. Significantly, A. niger was the only species resistant (25%) to voriconazole and has recently been reported as the species isolated from patients with COVID-19-associated pulmonary aspergillosis (CAPA). Phenotypic microarray showed that 83% of the isolates were susceptible to the 24 new compounds and novel compounds were identified for potentially effective combination treatment of fungal infections. This study also reports the first TR34/98 mutation in Aspergillus clinical isolates which is located in the cyp51A gene.

Updates in Laboratory Identification of Invasive Fungal Infection in Neonates

Invasive fungal infection (IFI) in immunocompromised neonates is significantly associated with high morbidity and mortality and has become the third most common infection in Neonatal Intensive Care Units. The early diagnosis of IFI for neonatal patients is difficult because of the lack of specific symptoms. The traditional blood culture remains the gold standard in clinical diagnosis for neonatal patients but it requires a long duration, which delays treatment initiation. Detections of fungal cell-wall components are developed for early diagnosis but the diagnostic accuracy in neonates needs to be improved. PCR-based laboratory methods, such as real-time PCR, droplet digital PCR, and the cationic conjugated polymer fluorescence resonance energy transfer (CCP-FRET) system, distinguish the infected fungal species by their specific nucleic acids and show a high sensitivity and specificity. Particularly, the CCP-FRET system, which contains a cationic conjugated polymer (CCP) fluorescent probe and pathogen-specific DNA labeled with fluorescent dyes, could identify multiple infections simultaneously. In the CCP-FRET system, the CCP and fungal DNA fragments can self-assemble into a complex with an electrostatic interaction and the CCP triggers the FRET effect under ultraviolet light to make the infection visible. Here, we summarize the recent laboratory methods for neonatal IFI identification and provide a new perspective for early clinical fungal diagnosis.

An Insight into In Vitro Antioxidant, Antimicrobial, Cytotoxic, and Apoptosis Induction Potential of Mangiferin, a Bioactive Compound Derived from Mangifera indica

Due to their low cost, toxicity, and health risks, medicinal plants have come to be seen as useful products and sources of biologically active compounds. Mangifera indica L., a medicinal plant with a long history, has a high bioactive metabolites content. Mangiferin (C₁₉H₁₈O₁₁) is primary isolated from M. indica's leaves, which has many pharmacological benefits. In this investigation, ultrasonic-assisted extraction with ethanol as the extraction solvent was applied to obtain mangiferin from a local type of M. indica leaves. HPLC was performed after a dichloromethane-ethyl acetate liquid-liquid fractionation method. Further, UV-vis, FTIR, and NMR spectroscopy were utilized to elucidate the structure. Interestingly, purified mangiferin displayed promising antimicrobial efficacy against a diverse variety of fungal and bacterial pathogens with MICs of 1.95-62.5 and 1.95-31.25 µg/mL, respectively. Time-kill patterns also showed that mangiferin had both bactericidal and fungicidal action. Furthermore, it exhibited strong radical dosage-dependent scavenging activity (IC₅₀ = 17.6 μg/mL) compared to vitamin C (Vc, IC₅₀ = 11.9 μg/mL), suggesting it could be developed into a viable antioxidant agent. To our delight, the IC₅₀ values of mangiferin for the MCF-7 and HeLa cell lines were 41.2 and 44.7 μg/mL, respectively, from MTT cell viability testing, and it was less harmful when tested against the noncancerous cell line. Notably, it significantly induced cell apoptosis in MCF-7 cells by 62.2-83.4% using annexin V-FITC/PI labeling. Hence, our findings suggest that mangiferin can be used in the medical industry to create therapeutic interventions and medication delivery systems for society.

The association between <i>Candida albicans</i> sensitivity to antimycotic drugs and the architecture of their microbial community in the oropharynx of HIV infected patients

Relevance. Candida infection remains relevant due to the wide spread of antimycotic-resistant strains of Candida fungi, especially among immunocompromised individuals. It was previously discovered that the Candida spp. microbial community in the biotope of the oropharynx of HIV infected patients is characterized by a certain architecture: they can be present in this biotope in the form of a monoculture or as association of co-isolates. It has been suggested that the architecture of the Candida microbial community may influence their resistance to antimycotic drugs. Purpose a comparative study of the association between the architecture of the C. albicans microbial community in the oropharynx of HIV infected patients with oropharyngeal candidiasis and their sensitivity to antimycotic drugs. Materials and methods. A microbiological study of 52 isolates of Candida fungi (C. albicans, C. glabrata, C. tropicalis and C. krusei) from the oropharynx of 31 HIV infected patients with clinical manifestations of oropharyngeal candidiasis aged 20 to 69 years with almost equal gender distribution was carried out. In the form of monocultures, 18 isolates were isolated, while 34 were identified as co-isolates, which formed 16 homogeneous communities that included strains of the same species, and 18 heterogeneous ones that consisted of fungi of various species. Results. It was found that heterogeneous communities of C. albicans were markedly distinguished by sensitivity to antimycotic drugs, in particular, by low sensitivity to imidazoles. Homogeneous communities practically did not differ from monocultural ones. The general properties of the C. non-albicans population were largely similar to those of C. albicans, but were characterized by lower heterogeneity in response to antimycotic drugs. Conclusion. The architecture of the community of C. albicans isolated from the oropharynx of HIV infected patients with clinical manifestations of oropharyngeal candidiasis affects their sensitivity to antimycotic drugs. When selecting effective antimycotic therapy for such patients, it is necessary to take into account the structure of the Candida spp. community in the oropharynx.

Clinical Features and Outcomes of Persistent Candidemia Caused by Candida albicans versus Non-albicans Candida Species: A Focus on Antifungal Resistance and Follow-Up Blood Cultures

The clinical distinctions among variations in Candida species, antifungal resistance (AFR), and clearance status of hospital-acquired persistent candidemia (HA-PC) remain uncertain. This secondary analysis of a retrospective cohort study aimed to assess the differences in HA-PC based on different Candida species, AFR, and persistent candidemia (PC) clearance status. A retrospective review was conducted using medical records from Tohoku University Hospital of patients for whom blood cultures were performed between January 2012 and December 2021. PC cases were categorized into groups based on Candida species, azole, or echinocandin resistance, as well as PC-clearance status, and the respective characteristics were analyzed. The HA-PC non-clearance group had a tendency toward higher 30–90-day and 90-day mortality rates compared to the HA-PC-clearance group in both the susceptible and resistant strain groups, with the former group demonstrating a statistically significant difference (odds ratio = 19, p = 0.028). The high mortality rate observed in the Candida non-albicans and resistant strain groups necessitates a more meticulous therapeutic management approach for PC. Follow-up blood cultures and confirmation of PC clearance are useful for improving the survival rates of both the HA-PC-susceptible and -resistant strain groups.

The Fragile Patient: Considerations in the Management of Invasive Mould Infections (IMIs) in India

Invasive mould infections (IMIs), which are mostly caused by Aspergillus spp. and Mucormycetes, are opportunistic infections that impose a substantial threat to patients who are considered to be 'fragile'. There is no fixed definition for fragile patients; however, patients with cancer or acquired immunodeficiency syndrome (AIDS), patients who have undergone organ transplants, and patients being treated in the intensive care units (ICUs) were considered fragile. Management of IMIs in fragile patients is challenging, owing to their compromised immune status. The diagnostic challenges associated with IMIs due to insufficient sensitivity and specificity of the current diagnostic tests lead to delayed treatment. A widening demographic of at-risk patients and a broadening spectrum of pathogenic fungi have added to the challenges to ascertain a definite diagnosis. A recent surge of mucormycosis associated with SARS-CoV-2 infections and the resultant steroid usage has been reported. Liposomal amphotericin B (L-AmB) is the mainstay for treating mucormycosis while voriconazole has displaced amphotericin B as the mainstay for treating Aspergillus infection due to its better response, improved survival, and fewer severe side effects. The selection of antifungal treatment has to be subjected to more scrutiny in fragile patients owing to their comorbidities, organ impairment, and multiple ongoing treatment modalities. Isavuconazole has been documented to have a better safety profile, stable pharmacokinetics, fewer drug-drug interactions, and a broad spectrum of coverage. Isavuconazole has thus found its place in the recommendations and can be considered a suitable option for treating fragile patients with IMIs. In this review, the authors have critically appraised the challenges in ascertaining an accurate diagnosis and current management considerations and suggested an evidence-based approach to managing IMIs in fragile patients.

Bioinformatics Approaches Applied to the Discovery of Antifungal Peptides

Antifungal peptides (AFPs) comprise a group of substances with a broad spectrum of activities and complex action mechanisms. They develop in nature via an evolutionary process resulting from the interactions between hosts and pathogens. The AFP database is experimentally verified and curated from research articles, patents, and public databases. In this review, we compile information about the primary databases and bioinformatics tools that have been used in the discovery of AFPs during the last 15 years. We focus on the classification and prediction of AFPs using different physicochemical properties, such as polarity, hydrophobicity, hydrophilicity, mass, acidic, basic, and isoelectric indices, and other structural properties. Another method for discovering AFPs is the implementation of a peptidomic approach and bioinformatics filtering, which gave rise to a new family of peptides that exhibit a broad spectrum of antimicrobial activity against Candida albicans with low hemolytic effects. The application of machine intelligence in the sphere of biological sciences has led to the development of automated tools. The progress made in this area has also paved the way for producing new drugs more quickly and effectively. However, we also identified that further advancements are still needed to complete the AFP libraries.

Antifungal Tolerance and Resistance Emerge at Distinct Drug Concentrations and Rely upon Different Aneuploid Chromosomes

Antifungal drug tolerance is a response distinct from resistance, in which cells grow slowly above the MIC. Here, we found that the majority (69.2%) of 133 Candida albicans clinical isolates, including standard lab strain SC5314, exhibited temperature-enhanced tolerance at 37°C and 39°C, and were not tolerant at 30°C. Other isolates were either always tolerant (23.3%) or never tolerant (7.5%) at these three temperatures, suggesting that tolerance requires different physiological processes in different isolates. At supra-MIC fluconazole concentrations (8 to 128 μg/mL), tolerant colonies emerged rapidly at a frequency of ~10^-3. In liquid passages over a broader range of fluconazole concentrations (0.25 to 128 μg/mL), tolerance emerged rapidly (within one passage) at supra-MICs. In contrast, resistance appeared at sub-MICs after 5 or more passages. Of 155 adaptors that evolved higher tolerance, all carried one of several recurrent aneuploid chromosomes, often including chromosome R, alone or in combination with other chromosomes. Furthermore, loss of these recurrent aneuploidies was associated with a loss of acquired tolerance, indicating that specific aneuploidies confer fluconazole tolerance. Thus, genetic background and physiology and the degree of drug stress (above or below the MIC) influence the evolutionary trajectories and dynamics with which antifungal drug resistance or tolerance emerges. IMPORTANCE Antifungal drug tolerance differs from drug resistance: tolerant cells grow slowly in drug, while resistant cells usually grow well, due to mutations in a few known genes. More than half of Candida albicans clinical isolates have higher tolerance at body temperature than they do at the lower temperatures used for most lab experiments. This implies that different isolates achieve drug tolerance via several cellular processes. When we evolved different strains at a range of high drug concentrations above inhibitory levels, tolerance emerged rapidly and at high frequency (one in 1,000 cells) while resistance appeared only later at very low drug concentrations. An extra copy of all or part of chromosome R was associated with tolerance, while point mutations or different aneuploidies were seen with resistance. Thus, genetic background and physiology, temperature, and drug concentration all influence how drug tolerance or resistance evolves.

Secondary cutaneous aspergillosis in a child with Behçet’s disease: a case-based update

Background

Invasive aspergillosis (IA) is one of the rarest opportunistic fungal infections and has increased in frequency worldwide in recent years. It is a life-threatening infection associated with high mortality rates. Invasive pulmonary aspergillosis (IPA) is the most severe form of the disease. Extrapulmonary forms can develop as a primary infection or occur as part of a disseminated infection from the lung in severely immunocompromised patients. The major limitation in the management of these infections is the challenge of early diagnosis.

Case presentation

Here we report a case of secondary cutaneous aspergillosis that developed from extensive pulmonary aspergillosis in a 3-year-old female who underwent immunosuppressive therapy for a diagnosed Behçet disease (BD). Aspergillus hyphae were identified on skin biopsies. Cultures grew Aspergillus fumigatus. The diagnosis of cutaneous aspergillosis enabled us to diagnose IPA, although there was no mycopathological proof of lung infection. The patient was successfully treated with voriconazole (8 mg/kg/day) and surgical debridement of the skin lesion.

Conclusions

Although cutaneous involvement in aspergillosis is extremely uncommon, it may be the presenting feature in some cases, allowing for an accurate and timely diagnosis of deeply infected sites. Accordingly, when evaluating skin lesions in immunocompromised individuals, especially debilitated children with underlying diseases requiring long-term immunosuppressive agents, cutaneous aspergillosis should be vigilantly considered.

Ophthalmologic Examination and Echocardiography Should be the Essential Components of Candidemia Bundle

Objective

Candidemia is the most common form of invasive candidiasis, and it is associated with end-organ involvement, prolonged hospitalization, increased mortality, and higher healthcare costs. Candidemia can lead to metastatic heart and ocular infections. This study aimed to define the incidence, characteristics, and mortality of candidemia episodes and compare the data with our center's previous results.

Materials and Methods

In this single-center retrospective observational study, we enrolled 250 patients over 18 years diagnosed with candidemia between January 2015 and December 2020. We obtained patients' demographic, clinical, laboratory, and therapeutic data from medical records. An ophthalmologic examination and screening with echocardiography were carried out within the first week after candidemia diagnosis.

Results

There were 275 candidemia episodes from 250 patients. The incidence of candidemia was 2.8/1000 admissions and 5.68/ 10,000 inpatient days, higher than our previous results (1.23/1000 and 3.29/10,000). The median age was 65 (interquartile range [IQR]=52-75) years. Malignancies were the most frequent comorbidity (50%). The most common type was Candida albicans (n=115, 41.8%). Candida glabrata (n=61, 22.2%) was common, particularly in surgical patients, patients with malignancy, and critically ill patients. There was Infectious disease consultation in 93.3% (257) episodes.The ophthalmoscopic examination was made in 145 episodes (52.7%), and ophthalmitis was detected in 16 (11.0%). Echocardiography was performed in 139 (50.5%) episodes; one case had an endocarditis diagnosis. The 30-day mortality was 44.7% (n=123). Mortality rates in C. glabrata and Candida krusei infections were higher (54.1% and 66.7). The factors related to mortality were intensive care unit requirement (p=0.0001), chronic liver disease (p=0.005), corticosteroid usage (p=0.0001), previous antibiotic usage (p=0.013), multiple antibiotic usage ( p=0.020), and CVC related candidemia (p=0.010).

Conclusion

Because of the life-threatening complications such as endocarditis, increased mortality rates, and higher healthcare costs, systematic and comprehensive candidemia bundle applications would be effective strategies for providing an effective antifungal stewardship program.

Dermatology mycology diagnostics in Ireland: National deficits identified in 2022 that are relevant internationally

BACKGROUND

Conventional testing methods for dermatophytes are time-consuming, and resource limitations in our institution have prompted curtailed access to these diagnostics.

OBJECTIVES

Evaluation of our hospital's dermatological mycology diagnostic services and similar services nationally.

METHODS

This was a retrospective observational study on skin, hair and nail mycology samples in our institution comparing twenty five-year periods (2011-2015 and 2016-2021), including analysis of dermatology clinic data and correspondence related to fungal infection. A survey of national public hospitals' laboratories was conducted to evaluate their mycology testing capabilities.

RESULTS

The total 5 year test count prior to curtailment was 4851 specimens comprising 90% (n = 4344) from general practice and 6% (n = 290) from dermatology clinics. For the 5 years post curtailment, 64.5% (582/903) of specimens were from dermatology clinics. Dermatology clinic data demonstrated doubling of attendances (for all conditions) and of correspondence related to fungal infection. During this time also, national dermatological antifungal purchasing increased 11%. Ten of 28 Irish public hospital laboratories reported the provision of in-house dermatological mycology testing, and none had routine availability of susceptibility or molecular testing of dermatophytes.

CONCLUSION

This study is the first to report an appraisal of dermatological fungal diagnostic services in Ireland. Insufficient testing capacity implies that patients are either being treated for fungal infection without appropriate diagnostic confirmation, or being left untreated because of the lack of access to diagnostics. The introduction of molecular detection methods and susceptibility systems would enhance testing capabilities and reduce the requirement for the external referral.