Advances and challenges in management of invasive mycoses

Natural Substances as Valuable Alternative for Improving Conventional Antifungal Chemotherapy: Lights and Shadows

Fungi are eukaryotic organisms with relatively few pathogenic members dangerous for humans, usually acting as opportunistic infections. In the last decades, several life-threatening fungal infections have risen mostly associated with the worldwide extension of chronic diseases and immunosuppression. The available antifungal therapies cannot combat this challenge because the arsenal of compounds is scarce and displays low selective action, significant adverse effects, and increasing resistance. A growing isolation of outbreaks triggered by fungal species formerly considered innocuous is being recorded. From ancient times, natural substances harvested from plants have been applied to folk medicine and some of them recently emerged as promising antifungals. The most used are briefly revised herein. Combinations of chemotherapeutic drugs with natural products to obtain more efficient and gentle treatments are also revised. Nevertheless, considerable research work is still necessary before their clinical use can be generally accepted. Many natural products have a highly complex chemical composition, with the active principles still partially unknown. Here, we survey the field underlying lights and shadows of both groups. More studies involving clinical strains are necessary, but we illustrate this matter by discussing the potential clinical applications of combined carnosic acid plus propolis formulations.

Insight into the Antifungal Effects of Propolis and Carnosic Acid—Extension to the Pathogenic Yeast Candida glabrata: New Propolis Fractionation and Potential Synergistic Applications

Fungi have traditionally been considered opportunistic pathogens in primary infections caused by virulent bacteria, protozoan, or viruses. Consequently, antimycotic chemotherapy is clearly less developed in comparison to its bacterial counterpart. Currently, the three main families of antifungals (polyenes, echinocandins, and azoles) are not sufficient to control the enormous increase in life-threatening fungal infections recorded in recent decades. Natural substances harvested from plants have traditionally been utilized as a successful alternative. After a wide screening of natural agents, we have recently obtained promising results with distinct formulations of carnosic acid and propolis on the prevalent fungal pathogens Candida albicans and Cryptococcus neoformans. Here, we extended their use to the treatment against the emerging pathogenic yeast Candida glabrata, which displayed lower susceptibility in comparison to the fungi mentioned above. Taking into account the moderate antifungal activity of both natural agents, the antifungal value of these combinations has been improved through the obtention of the hydroethanolic fractions of propolis. In addition, we have demonstrated the potential clinical application of new therapeutical designs based on sequential pre-treatments with carnosic/propolis mixtures, followed by exposure to amphotericin B. This approach increased the toxic effect induced by this polyene.

Antifungal activity and potential mechanism of action of caspofungin in combination with ribavirin against Candida albicans

The number of invasive fungal infections has increased dramatically, resulting in high morbidity and mortality among immunocompromised patients. With increasing use of caspofungin (CAS), resistant strains have emerged frequently and led to limitations in the treatment of patients with severe invasive Candida albicans infections. Combination therapy is an important method to deal with this issue. As such, this study investigated the activity of CAS in combination with ribavirin (RBV) against C. albicans. The results of this in-vitro study showed that the minimum inhibitory concentrations (MICs) of CAS and RBV when they were used as monotherapy were 0.5-1 μg/mL and 2-8 μg/mL, respectively, while the MIC of CAS decreased from 0.5-1 μg/mL to 0.0625-0.25 μg/mL when used in combination with RBV, with a fractional inhibitory concentration index (FICI) ≤0.5. In addition, the RBV + CAS combination group displayed synergistic effects against C. albicans biofilm over 4 h; the sessile MIC (sMIC) of CAS decreased from 0.5-1 µg/mL to 0.0625-0.25µg/mL and the sMIC of RBV decreased from 4-16 µg/mL to 1-2 µg/mL, with FICI <0.5. The survival of C. albicans-infected Galleria mellonella was prolonged, the fungal burden was decreased, and the area of tissue damage was reduced after combination therapy. Further study showed that the mechanisms of action of the synergistic effect were related to the inhibition of biofilm formation, the inhibition of hyphal growth, and the activation of metacaspases, but were not related to the accumulation of reactive oxygen species. It is hoped that these findings will contribute to the understanding of drug resistance in C. albicans, and provide new insights for the application of RBV.

Pulmonary Mucormycosis and hydatid cyst: A case report

Mucormycosis is a group of life-threatening diseases caused by a fungus of the Mucoraceae family and has a higher mortality rate compared with other known fungal infections. Hydatid cyst, caused by Echinococcus, is a crucial health concern in endemic areas and the disease is characterized by slow-growing cysts in the liver, lungs, or other organs. In this report, a woman with coexistence of hydatid cyst and Mucormycosis is introduced. The patient was a 52-year-old woman with approximately 6 years' history of uncontrolled diabetes mellitus and hypothyroidism, who presented with cough, sputum, and dyspnea 2 months ago. On the initial auscultation of the lungs, there was a decreased sound at the base of the left lung, and she had a fever. In blood tests, she had a high titer of erythrocyte sedimentation rate and 3+ C-Reactive Protein. The symptoms in favor of hydatid cyst were observed in lung computed tomography and in pleural needle biopsy, hydatid cyst was confirmed. With this indication, she underwent wedge resection, and resection of the left lower lung cyst. Two samples are taken from the cyst side and the pathology report was consistent with Mucormycosis (wide filaments with a 90-degree angle). The patient was immediately treated with liposomal amphotericin for 4 weeks. The Lung CT scan was performed before and after treatment. Albendazole was treated to treat hydatid cyst. After discharge, the treatment of the patient continued with oral Posaconazole, and after the treatment finalization, the general condition of the patient was good, and she did not have any complaints. In pulmonary diseases that do not respond significantly to surgical treatment (such as hydatid cyst), fungal disease (mucor) must be considered simultaneously. Mucormycosis is more prevalent in patients with uncontrolled diabetes, and it is necessary to be considered if these patients were infected with pneumonia and their symptoms did not improve with usual treatments.

Curcumin affects function of Hsp90 and drug efflux pump of Candida albicans

Candida albicans is a pathogenic yeast that causes candidiasis in immunocompromised patients. The overuse of antifungal drugs has led to the development of resistance to such drugs by this fungus, which is a major challenge in antifungal chemotherapy. One approach to this problem involves the utilization of new natural products as an alternative source of antifungals. Curcumin, one such natural product, has been widely studied as a drug candidate and is reported to exhibit antifungal activity against C. albicans. Although studies of the mechanism of curcumin against human cancer cells have shown that it inhibits heat shock protein 90 (Hsp90), little is known about its function against C. albicans. In this paper, using a doxycycline-mediated HSP90 strain and an HSP90-overexpressing strain of C. albicans, we demonstrated that the curcumin triggered a decrease in Hsp90 by affecting it at the post-transcriptional level. This also led to the downregulation of HOG1 and CDR1, resulting in a reduction of the stress response and efflux pump activity of C. albicans. However, the inhibition of HSP90 by curcumin was not due to the inhibition of transcription factors HSF1 or AHR1. We also found that curcumin can not only decrease the transcriptional expression of CDR1, but also inhibit the efflux pump activity of Cdr1. Hence, we conclude that disruption of HSP90 by curcumin could impair cell growth, stress responses and efflux pump activity of C. albicans.

Antifungal Effect of Penicillamine Due to the Selective Targeting of L-Homoserine O-Acetyltransferase

Due to the apparent similarity of fungal and mammalian metabolic pathways, the number of established antifungal targets is low, and the identification of novel ones is highly desirable. The results of our studies, presented in this work, indicate that the fungal biosynthetic pathway of L-methionine, an amino acid essential for humans, seems to be an attractive perspective. The MET2 gene from Candida albicans encoding L-homoserine O-acetyltransferase (CaMet2p), an enzyme catalyzing the first step in that pathway, was cloned and expressed as the native or the oligo-His-tagged fusion protein in Escherichia coli. The recombinant enzymes were purified and characterized for their basic molecular properties and substrate specificities. The purified MET2 gene product revealed the appropriate activity, catalyzed the conversion of L-homoserine (L-Hom) to O-acetyl-L-homoserine (OALH), and exhibited differential sensitivity to several L-Hom or OALH analogues, including penicillamine. Surprisingly, both penicillamine enantiomers (L- and D-Pen) displayed comparable inhibitory effects. The results of the docking of L- and D-Pen to the model of CaMet2p confirmed that both enantiomeric forms of the inhibitor are able to bind to the catalytic site of the enzyme with similar affinities and a similar binding mode. The sensitivity of some fungal cells to L-Pen, depending on the presence or absence of L-Met in the medium, clearly indicate Met2p targeting. Moreover, C. glabrata clinical strains that are resistant to fluconazole displayed a similar susceptibility to L-Pen as the wild-type strains. Our results prove the potential usefulness of Met2p as a molecular target for antifungal chemotherapy.

Antifungal Role of Common Indian Spices & Herbs: A Narrative Review

Abstract:

A large variety of spices can be found in kitchens worldwide. The usage varies from region to region as per the cuisine. They hold nutritional values and are being exploited for their anticancer, antifungal, antibacterial, antiulcer, anti-inflammatory properties. This study highlights some of the commonly used Indian spices for their antifungal properties and summarizes their potential antifungal activity. Fungal diseases are deep-rooted and cause acute/chronic infections in humans, mainly Aspergillus and Candida species. As the tropical climate provides a breeding ground for fungal infections, such regions share a huge load of mycoses. Various spices have been shown to be effective against treating fungal diseases. The current study focuses on the potential anti-fungal role of the spices and reviews the current literature on the possible mechanism of action of the active compounds of these spices concerning the commonly used antifungal drugs. The spices consist of essential oils that work by inhibition mycotoxin biosynthesis, or disrupting and inhibiting cell wall formation and inhibiting efflux pumps and are comparable to the currently available antifungal drugs.

Hyper-Synergistic Antifungal Activity of Rapamycin and Peptide-Like Compounds against Candida albicans Orthogonally via Tor1 Kinase

Candida albicans is a life-threatening, opportunistic fungal pathogen with a high mortality rate, especially within the immunocompromised populations. Multidrug resistance combined with limited antifungal drugs even worsens the situation. Given the facts that the current drug discovery strategies fail to deliver sufficient antifungals for the emerging multidrug resistance, we urgently need to develop novel approaches. By systematically investigating what caused the different antifungal activity of rapamycin in RPMI 1640 and YPD, we discovered that peptide-like compounds can generate a hyper-synergistic antifungal effect with rapamycin on both azole-resistant and sensitive clinical C. albicans isolates. The minimum inhibitory concentration (MIC) of rapamycin reaches as low as 2.14 nM (2^-9 μg/mL), distinguishing this drug combination as a hyper-synergism by having a fractional inhibitory concentration (FIC) index ≤ 0.05 from the traditional defined synergism with an FIC index < 0.5. Further studies reveal that this hyper-synergism orthogonally targets the protein Tor1 and affects the TOR signaling pathway in C. albicans, very likely without crosstalk to the stress response, Ras/cAMP/PKA, or calcineurin signaling pathways. These results lead to a novel strategy of controlling drug resistant C. albicans infection in the immunocompromised populations. Instead of prophylactically administering other antifungals with undesirable side-effects for extended durations, we now only need to coadminister some nontoxic peptide additives. The novel antifungal strategy approached in this study not only provides a new therapeutic method to control fungal infections in rapamycin-taking immunocompromised patients but also mitigates the immunosuppressive side-effects of rapamycin, repurposing rapamycin as an antifungal agent with wide applications.

Secretory Proteases of the Human Skin Microbiome

The human skin is our outermost layer and serves as a protective barrier against external insults. Advances in next generation sequencing have enabled the discoveries of a rich and diverse community of microbes - bacteria, fungi and viruses that are residents of this surface. The genomes of these microbes also revealed the presence of many secretory enzymes. In particular, proteases which are hydrolytic enzymes capable of protein cleavage and degradation are of special interest in the skin environment which is enriched in proteins and lipids. In this minireview, we will focus on the roles of these skin-relevant microbial secreted proteases, both in terms of their widely studied roles as pathogenic agents in tissue invasion and host immune inactivation, and their recently discovered roles in inter-microbial interactions and modulation of virulence factors. From these studies, it has become apparent that while microbial proteases are capable of a wide range of functions, their expression is tightly regulated and highly responsive to the environments the microbes are in. With the introduction of new biochemical and bioinformatics tools to study protease functions, it will be important to understand the roles played by skin microbial secretory proteases in cutaneous health, especially the less studied commensal microbes with an emphasis on contextual relevance.

Molecular Umbrella as a Nanocarrier for Antifungals

A molecular umbrella composed of two O-sulfated cholic acid residues was applied for the construction of conjugates with cispentacin, containing a “trimethyl lock” (TML) or o-dithiobenzylcarbamoyl moiety as a cleavable linker. Three out of five conjugates demonstrated antifungal in vitro activity against C. albicans and C. glabrata but not against C. krusei, with MIC₉₀ values in the 0.22–0.99 mM range and were not hemolytic. Antifungal activity of the most active conjugate 24c, containing the TML–pimelate linker, was comparable to that of intact cispentacin. A structural analogue of 24c, containing the Nap-NH₂ fluorescent probe, was accumulated in Candida cells, and TML-containing conjugates were cleaved in cell-free extract of C. albicans cells. These results suggest that a molecular umbrella can be successfully applied as a nanocarrier for the construction of cleavable antifungal conjugates.

The antifungal activity of caspofungin in combination with antifungals or non-antifungals against Candida species in vitro and in clinical therapy

Introduction: Candida species have been regarded as global health threats due to their ability to cause invasive infections. It is challenging to treat Candida bloodstream infections, which are associated with high mortality levels. Monotherapy with antifungals is sometimes not effective against severe Candida infections, and combination therapy is needed in clinical practice.Areas covered: This review was undertaken based on data from a PubMed search for English language reports published before March 2021 by using the terms 'caspofungin,' 'Candida species,' 'combination therapy,' 'antifungal effect,' and 'novel antifungal agent.'Expert opinion: Combination therapy is an empirical strategy for treating refractory Candida infections. Caspofungin has been recommended to treat candidaemia. Caspofungin in combination therapy has some applications, while the efficacy of combination therapy in the treatment of refractory Candida infections needs more study, such as randomized controlled trials. In addition, novel compounds or drugs with potential antifungal activities have been examined, and some of them exhibit synergistic interactions with caspofungin. Thus, the antifungal activity of caspofungin in combination with antifungals or non-antifungals against Candida species in vitro and in clinical therapy is summarized.

Clinical manifestations, diagnosis, and treatment outcome of CNS aspergillosis: A systematic review of 235 cases

Aspergillus is a ubiquitous ascomycete that can cause a variety of clinical presentations depending on immune status. Central nervous system aspergillosis is a fatal disease with non-specific clinical features. The aim of this systematic review was to evaluate the epidemiology, clinical features, diagnosis and therapeutic interventions in CNS aspergillosis patients. We also aimed to examine the possible predictors of mortality in neuroaspergillosis. Literature search was performed in Medline, PubMed, and Google scholar and all patients≥18 years with proven CNS aspergillosis were included. A total of 175 articles (235 patients) were included in the final analysis. Their mean age was 51 years and the majority were male (57.4%). Overall case-fatality was 45.1%. Aspergillus fumigatus was the most common species (70.8%) followed by A. flavus (18.6%). Corticosteroids (22.6%), malignancy (19.1%) and diabetes mellitus (14%) were the most common risk factors. Neuroimaging findings included cerebral abscess (70.2%), meningitis (14%), infarction (13.2%) and mycotic aneurysm (8.9%). Disseminated disease (29.2% vs 17.8%, p 0.03), CSF hypoglycorrhachia (48.1% vs 22.2%, P: 0.001) and heightened CSF galactomannan (3.62 vs 2.0ng/ml, p 0.05), were the factors associated with poor outcome in neuroaspergillosis. Persons infected with Aspergillus flavus (13.1% vs 3.1%, P: 0.01), and having been treated with Voriconazole (51.9% vs 29.2%, P: 0.004) were more likely to survive. Our review will provide insight into the different spectrums of CNS aspergillosis. Notwithstanding the promising role of Voriconazole, future work is required to ascertain the role of combination antifungal therapy.

Machaerium acutifolium lectin alters membrane structure and induces ROS production in Candida parapsilosis

Lectins are a group of widely distributed and structurally heterogeneous proteins of nonimmune origin. These proteins have the ability to interact with glycans present on cell surfaces and elicit diverse biological activities. Machaerium acutifolium lectin (MaL) is an N-acetyl-D-glucosamine-binding lectin that exhibits antinociceptive activity via transient receptor potential cation channel subfamily V member 1 (TRPV1). Lectins that have the ability to recognize and interact with N-acetyl-D-glucosamine residues are potential candidates for studies of fungicidal activity. In this work, we show that MaL has antifungal activity against Candida species, and we describe its mode of action towards Candida parapsilosis. MaL inhibited the growth of C. albicans and C. parapsilosis. However, MaL was more potent against C. parapsilosis. The candidacidal mode of action of MaL on C. parapsilosis involves enhanced cell permeabilization, alteration of the plasma membrane proton-pumping ATPase function (H+-ATPase), induction of oxidative stress, and DNA damage. MaL also exhibited antibiofilm activity and noncytotoxicity to Vero cells. These results indicate that MaL is a promising candidate for the future development of a new, natural, and safe drug for the treatment of infections caused by C. parapsilosis.

Dual DNA Barcoding for the Molecular Identification of the Agents of Invasive Fungal Infections

Invasive fungal infections, such as aspergillosis, candidiasis, and cryptococcosis, have significantly increased among immunocompromised people. To tackle these infections the first and most decisive step is the accurate identification of the causal pathogen. Routine identification of invasive fungal infections has progressed away from culture-dependent methods toward molecular techniques, including DNA barcoding, a highly efficient and widely used diagnostic technique. Fungal DNA barcoding previously relied on a single barcoding region, the internal transcribed spacer (ITS) region. However, this allowed only for 75% of all fungi to be correctly identified. As such, the translational elongation factor 1α (TEF1α) was recently introduced as the secondary barcode region to close the gap. Both loci together form the dual fungal DNA barcoding scheme. As a result, the ISHAM Barcoding Database has been expanded to include sequences for both barcoding regions to enable practical implementation of the dual barcoding scheme into clinical practice. The present study investigates the impact of the secondary barcode on the identification of clinically important fungal taxa, that have been demonstrated to cause severe invasive disease. Analysis of the barcoding regions was performed using barcoding gap analysis based on the genetic distances generated with the Kimura 2-parameter model. The secondary barcode demonstrated an improvement in identification for all taxa that were unidentifiable with the primary barcode, and when combined with the primary barcode ensured accurate identification for all taxa analyzed, making DNA barcoding an important, efficient and reliable addition to the diagnostic toolset of invasive fungal infections.

Emerging fungal infections in solid organ transplant recipients: Guidelines of the American Society of Transplantation Infectious Diseases Community of Practice

These updated AST-IDCOP guidelines review the epidemiology, diagnosis, and management of emerging fungi after organ transplantation. Infections due to numerous generally innocuous fungi are increasingly recognized in solid organ transplant (SOT) recipients, comprising about 7%-10% of fungal infections in this setting. Such infections are collectively referred to as emerging fungal infections and include Mucormycetes, Fusarium, Scedosporium, and dematiaceous fungi among others. The causative organisms are diverse in their pathophysiology, uncommon in the clinical setting, have evolving nomenclature, and are often resistant to multiple commonly used antifungal agents. In recent years significant advances have been made in understanding of the epidemiology of these emerging fungal infections, with improved diagnosis and expanded treatment options. Still, treatment guidelines are generally informed by and limited to experience from cohorts of patients with hematological malignancies and/or solid and stem cell transplants. While multicenter randomized controlled trials are not feasible for these uncommon infections in SOT recipients, collaborative prospective studies can be valuable in providing information on the epidemiology, clinical manifestations, treatment strategies, and outcomes associated with the more commonly encountered infections.

Clinical diagnostic value of spiral CT in invasive pulmonary fungal infection

This study explored the diagnostic value of computed tomography (CT) in pulmonary fungal infection to provide a theoretical basis for the clinical diagnosis of pulmonary fungal infections. The clinical data of 82 suspected invasive fungal infection (IFI) patients admitted to the Department of Critical Care Medicine of The Affiliated Hospital of Qingdao University from January 2016 to May 2018 were retrospectively analyzed, and 64 of them were diagnosed with IFI by pathology and sputum culture. The CT results of the 82 patients were compared with the X-ray results in order to analyze the diagnostic value of CT imaging. Taking pathological diagnosis as the gold standard, the number of true-negative, true-positive, false-negative and false-positive results in X-ray diagnosis were 13, 43, 21 and 5, respectively, while those in CT diagnosis were 11, 59, 5 and 7, respectively. The sensitivity, specificity, accuracy, positive coincidence rate, negative coincidence rate, misdiagnosis rate and missed diagnosis rate of CT in IFI were 92.18, 61.11, 85.37, 89.39, 68.75, 38.89 and 7.81%, respectively, while those of X-ray in IFI were 67.19, 72.22, 68.29, 89.58, 38.24, 27.78 and 32.81%, respectively. The sensitivity, accuracy and negative coincidence rate of CT in the diagnosis of IFI were significantly higher than those of X-ray (P<0.05), with a sensitivity of 92.18%, which indicates that CT has a higher diagnostic value in IFI. The results of CT combined with the basic condition of the patients can be used to initially diagnose pulmonary fungal infections, which is of high diagnostic value and can improve clinical treatment.

Effectiveness and Safety of Micafungin in Managing Invasive Fungal Infections among Patients in Greece with Hematologic Disorders: The ASPIRE Study

INTRODUCTION

Invasive candidiasis (IC) can be a life-threatening infection in immunocompromised patients, particularly those with cancer, hematologic diseases and/or hematopoietic stem cell transplantation (HSCT) recipients. The objective of this study was to evaluate the effectiveness of micafungin in patients with hematologic malignancies or HSCT recipients, relevant to clinical presentation of IC, in real-life practice in Greece.

METHODS

ASPIRE was a phase IV, multicenter, non-interventional, prospective cohort study, conducted at ten tertiary hospitals in Greece, in adults with hematologic disease. Micafungin treatment for IC or prophylaxis for Candida infection was administered per standard clinical practice until a clinical outcome (success or failure) was reached. Treatment success was defined by the EORTC/MSG criteria for invasive fungal infections (IFI) and was assessed by the investigator. Treatment discontinuation and safety were also evaluated.

RESULTS

One hundred forty-three patients were enrolled. Median age was 62; 85 (59.4%) patients were male, and 133 (93.0%) had Greek ethnicity. One hundred twenty-six (88.1%) patients had hematologic malignancies, and 21 (14.7%) had received HSCT. Prophylaxis was administered to 74 (51.7%) patients [median (range) dose: 50 (50-150) mg/day] with no signs of IFI. Overall, 52 (36.4%) patients with possible IFI at baseline received micafungin treatment [100 (50-125) mg/day] versus 12 (17.2%) with probable [100 (75-150) mg/day] and 5 (3.5%) with confirmed [125 (100-150) mg/day] IFI. Treatment success was 91.6% (95% CI 85.80-95.59; n = 131) overall and 90.5% (n = 67) in patients receiving prophylaxis. Median time on treatment was 13 days. Treatment discontinuation (n = 26; 18.2%) was not related to adverse events. No treatment-related serious adverse events were reported.

CONCLUSION

Micafungin treatment for IC or prophylaxis for Candida infection was effective and well tolerated in patients with hematologic disorders in clinical practice in Greece. These results demonstrate that micafungin could be used more widely for prophylaxis. Further work is required to determine the efficacy and safety of micafungin for the management of IFIs in hematologic settings.

FUNDING

Astellas Pharma Inc.

[Aspergillus in airway material : Ignore or treat?]

Fungi of the genus Aspergillus are ubiquitously present. Even though humans inhale Aspergillus spores daily under natural conditions, Aspergillus-associated pulmonary diseases only occur under special circumstances. Whether an Aspergillus-associated disease develops and which type of Aspergillus-associated disease develops depends on the constitution of the host. The spectrum of Aspergillus-associated pulmonary diseases ranges from allergic diseases, such as hypersensitivity pneumonitis to allergic infectious diseases, such as allergic bronchopulmonary aspergillosis (ABPA) and bronchocentric granulomatosis (BG) to infectious diseases, such as invasive (IA) or semi-invasive aspergillosis (SIA) and chronic pulmonary aspergillosis (CPA). Identification of Aspergillus spp. from sputum or bronchopulmonary secretions is not sufficient for a definitive diagnosis of Aspergillus-associated infections. The gold standard is the identification of Aspergillus spp. from lung tissue by culture or by histopathological methods; however, in clinical practice the decision to initiate antifungal therapy is more often based on immunological methods, such as the detection of Aspergillus-specific IgG antibodies from peripheral blood or galactomannan antigens from bronchoalveolar lavages. Acute IA or SIA infections have a high mortality and require immediate antifungal therapy. With rare exceptions CPA cannot be cured by medicinal therapy alone; however, active CPA can be brought into remission with antifungal therapy. Eradication of Aspergillus in CPA can as a rule only be successful using a combined antimycotic and surgical intervention.

The epidemiology of non-Candida yeast isolated from blood: The Asia Surveillance Study

Background

Current guidelines recommend echinocandins as first‐line therapy for candidemia. However, several non‐Candida yeast are non‐susceptible to echinocandins (echinocandin non‐susceptible yeast, ENSY), including Cryptococcus, Geotrichum, Malassezia, Pseudozyma, Rhodotorula, Saprochaete, Sporobolomyces and Trichosporon. In laboratories that are not equipped with rapid diagnostic tools, it often takes several days to identify yeast, and this may lead to inappropriate presumptive use of echinocandins in patients with ENSY fungemia. The aim of this study was to determine the distribution of ENSY species during a 1‐year, laboratory surveillance programme in Asia.

Methods

Non‐duplicate yeast isolated from blood or bone marrow cultures at 25 hospitals in China, Hong Kong, India, Singapore, Taiwan and Thailand were analysed. Isolates were considered to be duplicative if they were obtained within 7 days from the same patient.

Results

Of 2155 yeast isolates evaluated, 175 (8.1%) were non‐Candida yeast. The majority of non‐Candida yeast were ENSY (146/175, 83.4%). These included Cryptococcus (109 isolates), Trichosporon (23), Rhodotorula (10) and Malassezia (4). The proportion of ENSY isolates (146/2155, 6.7%) differed between tropical (India, Thailand and Singapore; 51/593, 8.6%) and non‐tropical countries/regions (China, Hong Kong and Taiwan; 95/1562, 6.1%, P = 0.038). ENSY was common in outpatient clinics (25.0%) and emergency departments (17.8%) but rare in intensive care units (4.7%) and in haematology‐oncology units (2.9%). Cryptococcus accounted for the majority of the non‐Candida species in emergency departments (21/24, 87.5%) and outpatient clinics (4/5, 80.0%).

Conclusions

Isolation of non‐Candida yeast from blood cultures was not rare, and the frequency varied among medical units and countries.

Intracranial Fungal Infection After Solid-Organ Transplant

Neurologic complications after solid-organ transplant reveal a great spectrum of pathologies. Intracranial hemorrhages, cerebral ischemic lesions, infarctions, lymphoproliferative disorders, and infections, including aspergillosis, have been observed after liver transplant. Fungi constitute nearly 5% of all central nervous system infections, mainly occurring in immunocompromised patients. The most common causative agent is Aspergillus species. It presents either as maxillary sinusitis or pulmonary infection. Brain involvement of Aspergillus carries a high rate of mortality. Aspergillosis presents in the forms of meningitis, mycotic aneurysms, infarctions, and mass lesions. Aspergillosis does not have a specific radiologic appearance. Parenchymal aspergillosis has heterogenous signal intensity (hypointense on T1-weighted and hyperintense on T2-weighted images). Here, we present 3 patients who underwent solid-organ transplant and developed central nervous system aspergillosis. Different modalities of neurosurgical intervention were performed in combination with chemotherapy as part of their fungal therapy.

Factor H Binds to Extracellular DNA Traps Released from Human Blood Monocytes in Response to Candida albicans

Upon systemic infection with human pathogenic yeast Candida albicans (C. albicans), human monocytes and polymorph nuclear neutrophilic granulocytes are the first immune cells to respond and come into contact with C. albicans. Monocytes exert immediate candidacidal activity and inhibit germination, mediate phagocytosis, and kill fungal cells. Here, we show that human monocytes spontaneously respond to C. albicans cells via phagocytosis, decondensation of nuclear DNA, and release of this decondensed DNA in the form of extracellular traps (called monocytic extracellular traps: MoETs). Both subtypes of monocytes (CD14⁺⁺CD16⁻/CD14⁺CD16⁺) formed MoETs within the first hours upon contact with C. albicans. MoETs were characterized by the presence of citrullinated histone, myeloperoxidase, lactoferrin, and elastase. MoETs were also formed in response to Staphylococcus aureus and Escherichia coli, indicating a general reaction of monocytes to infectious microbes. MoET induction differs from extracellular trap formation in macrophages as MoETs are not triggered by simvastatin, an inhibitor of cholesterol synthesis and inducer of extracellular traps in macrophages. Extracellular traps from both monocytes and neutrophils activate complement and C3b is deposited. However, factor H (FH) binds via C3b to the extracellular DNA, mediates cofactor activity, and inhibits the induction of the inflammatory cytokine interleukin-1 beta in monocytes. Altogether, the results show that human monocytes release extracellular DNA traps in response to C. albicans and that these traps finally bind FH via C3b to presumably support clearance without further inflammation.

Antifungal activity of the cationic antimicrobial polymer-polyhexamethylene guanidine hydrochloride and its mode of action

The antifungal activity of polyhexamethylene guanidine hydrochloride (PHMGH) was studied against various pathogenic fungi. PHMGH had more potent antifungal activity than amphotericin B, which is a commonly used antifungal drug, and also showed no hemolytic and lactate dehydrogenase release activities in the range of 1.25-40.0 μg mL^-1. PHMGH is a cationic polymer containing an amino group and a polymeric guanidine group. Based on its characteristics such as the cationic charge and hydrophobicity, the antifungal mechanism of PHMGH was investigated using Candida albicans, as a model organism. Flow cytometric contour-plot analysis and microscopy showed changes in the size and granularity of the cells after treatment with PHMGH. A membrane study using 1,6-diphenyl-1,3,5-hexatriene labelling indicated a great loss of phospholipid area in the plasma membrane following PHMGH treatment. To investigate the extent of the damage, fluorescein isothiocyanate-labelled dextran leakage from large unilamellar vesicles was observed, indicating that PHMGH acts on the fungal membranes by inducing pore formation, with the majority of pore size being between 2.3 and 3.3 nm. This mechanism was confirmed with ion transition assays using 3,3'-dipropylthiacarbocyanine iodide and an ion-selective electrode meter, which indicated that membrane depolarization involving K⁺ leakage was induced. Taken together, these results show that PHMGH exerts its fungicidal effect by forming pores in the cell membrane.

Homozygous deletion of ATC1 and NTC1 genes in Candida parapsilosis abolishes trehalase activity and affects cell growth, sugar metabolism, stress resistance, infectivity and biofilm formation

A double homozygous atc1Δ/atc1Δ/ntc1Δ/ntc1Δ mutant (atc1Δ/ntc1Δ KO) was constructed in the pathogen opportunistic yeast Candida parapsilosis by disruption of the two chromosomal alleles coding for NTC1 gene (encoding a neutral trehalase) in a Cpatc1Δ/atc1Δ background (atc1Δ KO strain, deficient in acid trehalase). The Cpatc1Δ/ntc1Δ KO mutant failed to counteract the inability of Cpatc1Δ cells to metabolize exogenous trehalose and showed a similar growth pattern on several monosaccharides and disaccharides. However, upon prolonged incubation in either rich medium (YPD) or nutrient-starved medium the viability of Cpatc1Δ cells exhibited a sensitive phenotype, which was augmented by further CpNTC1/NTC1 disruption. Furthermore, Cpatc1Δ/ntc1Δ KO cells had difficulty in resuming active growth in fresh YPD. This homozygous mutant also lacked any in vitro measurable trehalase activity, whether acid or neutral, suggesting that a single gene codes for each enzyme. By contrast, in Cpatc1Δ/ntc1Δ KO strain the resistance to oxidative and heat stress displayed by atc1Δ mutant was suppressed. Cpatc1Δ/ntc1Δ KO cells showed a significant decrease in virulence as well as in the capacity to form biofilms. These results point to a major role for acid trehalase (Atc1p) in the pathobiology of C. parapsilosis, whereas the activity of neutral trehalase can only partially counteract Atc1p deficiency. They also support the use of ATC1 and NTC1 genes as interesting antifungal targets.

International expert opinion on the management of infection caused by azole-resistant Aspergillus fumigatus

An international expert panel was convened to deliberate the management of azole-resistant aspergillosis. In culture-positive cases, in vitro susceptibility testing should always be performed if antifungal therapy is intended. Different patterns of resistance are seen, with multi-azole and pan-azole resistance more common than resistance to a single triazole. In confirmed invasive pulmonary aspergillosis due to an azole-resistant Aspergillus, the experts recommended a switch from voriconazole to liposomal amphotericin B (L-AmB; Ambisome(®)). In regions with environmental resistance rates of ≥10%, a voriconazole-echinocandin combination or L-AmB were favoured as initial therapy. All experts recommended L-AmB as core therapy for central nervous system aspergillosis suspected to be due to an azole-resistant Aspergillus, and considered the addition of a second agent with the majority favouring flucytosine. Intravenous therapy with either micafungin or L-AmB given as either intermittent or continuous therapy was recommended for chronic pulmonary aspergillosis due to a pan-azole-resistant Aspergillus. Local and national surveillance with identification of clinical and environmental resistance patterns, rapid diagnostics, better quality clinical outcome data, and a greater understanding of the factors driving or minimising environmental resistance are areas where research is urgently needed, as well as the development of new oral agents outside the azole drug class.

Opportunistic pathogen Candida albicans elicits a temporal response in primary human mast cells

Immunosuppressed patients are frequently afflicted with severe mycoses caused by opportunistic fungal pathogens. Besides being a commensal, colonizing predominantly skin and mucosal surfaces, Candida albicans is the most common human fungal pathogen. Mast cells are present in tissues prone to fungal colonization being expectedly among the first immune cells to get into contact with C. albicans. However, mast cell-fungus interaction remains a neglected area of study. Here we show that human mast cells mounted specific responses towards C. albicans. Collectively, mast cell responses included the launch of initial, intermediate and late phase components determined by the secretion of granular proteins and cytokines. Initially mast cells reduced fungal viability and occasionally internalized yeasts. C. albicans could evade ingestion by intracellular growth leading to cellular death. Furthermore, secreted factors in the supernatants of infected cells recruited neutrophils, but not monocytes. Late stages were marked by the release of cytokines that are known to be anti-inflammatory suggesting a modulation of initial responses. C. albicans-infected mast cells formed extracellular DNA traps, which ensnared but did not kill the fungus. Our results suggest that mast cells serve as tissue sentinels modulating antifungal immune responses during C. albicans infection. Consequently, these findings open new doors for understanding fungal pathogenicity.

Development of an inhaled controlled release voriconazole dry powder formulation for the treatment of respiratory fungal infection

The present research aimed to develop and characterize a sustained release dry powder inhalable formulation of voriconazole (VRZ) for invasive pulmonary aspergillosis. The developed formulations were studied for their in vitro release profile, aerosol, and physicochemical properties as well as interactions with lung epithelia in terms of toxicity and transport/uptake. VRZ and VRZ loaded poly lactide microparticles (VLM) were prepared by aqueous/organic cosolvent and organic spray drying, respectively. Powders were characterized using laser diffraction, differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD), dynamic vapor sorption (DVS), and electron microscopy. Aerosol performance was evaluated using an RS01 dry powder inhaler and in vitro cascade impaction. Uptake across Calu-3 lung epithelia was studied, using aerosol deposition of the powder onto cells cultured in an air interface configuration, and compared to dissolution using a conventional dialysis membrane. Additionally, toxicity of VRZ and VLM and the potential impact of transmembrane proteins on uptake were investigated. The particle size and the aerosol performance of spray-dried VRZ and VLM were suitable for inhalation purposes. VRZ exhibited a median volume diameter of 4.52 ± 0.07 μm while VLM exhibited 2.40 ± 0.05 μm. Spray-dried VRZ was crystalline and VLM amorphous as evaluated by DSC and XRPD, and both powders exhibited low moisture sorption between 0 and 90% RH (<1.2% w/w) by DVS. The fine particle fraction (FPF) (% aerosol <5 μm) for the VRZ was 20.86 ± 1.98% while the VLM showed significantly improved performance (p < 0.01) with an FPF of 43.56 ± 0.13%. Both VRZ and VLM were not cytotoxic over a VRZ concentration range of 1.2 nM to 30 μM, and the VLM particles exhibited a sustained release over 48 h after being deposited on the Calu-3 cell line or via conventional dialysis-based dissolution measurements. Lastly, VRZ exhibited polarized transport across epithelia with basal to apical transport being slower than apical to basal. Influx and efflux transports may also play a role as transport was altered in the presence of a number of inhibitors. This study has established an inhalable and sustained release powder of VRZ for targeting invasive pulmonary aspergillosis.

Multicenter evaluation of a lateral-flow device test for diagnosing invasive pulmonary aspergillosis in ICU patients

Introduction

The incidence of invasive pulmonary aspergillosis (IPA) in intensive care unit (ICU) patients is increasing, and early diagnosis of the disease and treatment with antifungal drugs is critical for patient survival. Serum biomarker tests for IPA typically give false-negative results in non-neutropenic patients, and galactomannan (GM) detection, the preferred diagnostic test for IPA using bronchoalveolar lavage (BAL), is often not readily available. Novel approaches to IPA detection in ICU patients are needed. In this multicenter study, we evaluated the performance of an Aspergillus lateral-flow device (LFD) test for BAL IPA detection in critically ill patients.

Methods

A total of 149 BAL samples from 133 ICU patients were included in this semiprospective study. Participating centers were the medical university hospitals of Graz, Vienna and Innsbruck in Austria and the University Hospital of Mannheim, Germany. Fungal infections were classified according to modified European Organization for Research and Treatment of Cancer/Mycoses Study Group criteria.

Results

Two patients (four BALs) had proven IPA, fourteen patients (sixteen BALs) had probable IPA, twenty patients (twenty-one BALs) had possible IPA and ninety-seven patients (one hundred eight BALs) did not fulfill IPA criteria. Sensitivity, specificity, negative predictive value, positive predictive value and diagnostic odds ratios for diagnosing proven and probable IPA using LFD tests of BAL were 80%, 81%, 96%, 44% and 17.6, respectively. Fungal BAL culture exhibited a sensitivity of 50% and a specificity of 85%.

Conclusion

LFD tests of BAL showed promising results for IPA diagnosis in ICU patients. Furthermore, the LFD test can be performed easily and provides rapid results. Therefore, it may be a reliable alternative for IPA diagnosis in ICU patients if GM results are not rapidly available.

Trial registration

ClinicalTrials.gov NCT02058316. Registered 20 January 2014.

Population-based analysis of invasive fungal infections, France, 2001-2010

These infections are underrecognized as a cause of death in the general population and high-risk groups.

To determine the epidemiology and trends of invasive fungal infections (IFIs) in France, we analyzed incidence, risk factors, and in-hospital death rates related to the most frequent IFIs registered in the national hospital discharge database during 2001–2010. The identified 35,876 IFI cases included candidemia (43.4%), Pneumocystis jirovecii pneumonia (26.1%), invasive aspergillosis (IA, 23.9%), cryptococcosis (5.2%), and mucormycosis (1.5%). The overall incidence was 5.9/100,000 cases/year and the mortality rate was 27.6%; both increased over the period (+1.5%, +2.9%/year, respectively). Incidences substantially increased for candidemia, IA, and mucormycosis. Pneumocystis jirovecii pneumonia incidence decreased among AIDS patients (−14.3%/year) but increased in non-HIV–infected patients (+13.3%/year). Candidemia and IA incidence was increased among patients with hematologic malignancies (>+4%/year) and those with chronic renal failure (>+10%/year). In-hospital deaths substantially increased in some groups, e.g., in those with hematologic malignancies. IFIs occur among a broad spectrum of non–HIV-infected patients and should be a major public health priority.

Development of voriconazole loaded large porous particles for inhalation delivery: effect of surface forces on aerosolisation performance, assessment of in vitro safety potential and uptake by macrophages

Inhalation delivery of voriconazole loaded large porous particles represent an effective and safe way to prolong pulmonary residence of voriconazole.

Applicability of the EORTC/MSG criteria for IFD in clinical practice

Invasive fungal disease (IFD) is a feared complication in patients with hematological malignancies. In 2008, the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycosis Study Group (EORTC/MSG) published updated criteria for the diagnostic workup within clinical studies for immunosuppressed patients with suspected fungal infection. We applied these criteria in a routine clinical setting with regard to their feasibility for bedside practice at our institution in a 1-year period. One hundred seventy consecutive patients with a recent history of chemotherapy-induced neutropenia (n = 100) or allogeneic stem cell recipients (n = 70) who had received a CT scan of the chest in search of pulmonary IFD were examined. We analyzed all available radiological and microbiological data according to the EORTC/MSG criteria. The quality of images was good in 94.7%, microbiological diagnostics performed in 94.1% patients. Five patients had histopathologic-proven IFD, 18 patients were classified as "probable," 55 patients as "possible" IFD, and 92 patients did not fulfill any criteria ("no IFD"). Microbiology revealed suggestive findings in 29 patients. These were either galactomannan antigen (Gm-AG) in serum (n = 18) and/or broncho-alveolar lavage (BAL) (n = 5). CT scan showed pulmonary infiltrates in 106 patients; 78 were classified as typical for IPA, further discriminated by morphology and number of nodules, as well as additional signs (halo, air crescent, cavity). We observed a better overall survival in patients without infiltrates compared to those with any type of infiltrate (p = 0.042) and a trend toward favorable survival in patients who had micronodular lesions (p = 0.058). We also found a higher probability of Gm-AG positivity in the group of allogeneic stem cell transplantation (allo-SCT) patients (p = 0.001) and a trend toward an association of Gm-AG positivity and positive findings on CT (p = 0.054). The applicability of criteria was good, both with regard to radiological and mycological evidence and sufficient for the categorization of IFD according to EORTC/MSG in the clinical setting. However, our findings suggest that feasibility improves with stringency of mycological workup, which is reflected in the two subgroups. Radiology harvests by far more suggestive findings which can only partly be correlated with mycological evidence. Although feasible, whether the EORTC/MSG criteria are the appropriate tool for early identification of IFD remains open for discussion.

Detection of Aspergillus flavus and A. fumigatus in Bronchoalveolar Lavage Specimens of Hematopoietic Stem Cell Transplants and Hematological Malignancies Patients by Real-Time Polymerase Chain Reaction, Nested PCR and Mycological Assays

BACKGROUND

Pulmonary aspergillosis (PA) is one of the most serious complications in immunocompromised patients, in particular among hematopoietic stem cell transplants (HSCT) and patients with hematological malignancies.

OBJECTIVES

The current study aimed to evaluate the incidence of PA and utility of molecular methods in HSCT and patients with hematological malignancies, four methods including direct examination, culture, nested polymerase chain reaction (PCR) and real-time PCR were performed on bronchoalveolar lavage (BAL) specimens in Tehran, Iran.

PATIENTS AND METHODS

During 16 months, 46 BAL specimens were obtained from individuals with allogeneic HSCT (n = 18) and patients with hematological malignancies (n = 28). Direct wet mounts with 20% potassium hydroxide (KOH) and culture on mycological media were performed. The molecular detection of Aspergillus fumigatus and A. flavus was done by amplifying the conserved sequences of internal transcribed spacer 1 (ITS1) ribosomal DNA by nested-PCR and the β-tubulin gene by TaqMan real-time PCR.

RESULTS

Seven (15.2%) out of 46 specimens were positive in direct examination and showed branched septate hyphae; 11 (23.9%) had positive culture including eight (72.7%) A. flavus and three (27.3%) A. fumigatus; 22 (47.8%) had positive nested-PCR and eight (17.4%) had positive real-time PCR. The incidence of invasive pulmonary aspergillosis (IPA) in these patients included proven IPA in 1 (2.2%), probable IPA in 10 (21.7%), possible IPA in 19 (41.3%) and not IPA in 16 cases (34.8%).

CONCLUSIONS

The incidence of IPA in allogeneic HSCT and patients with hematological malignancies was relatively high and A. flavus was the most common cause of PA. As molecular methods had higher sensitivity, it may be useful as screening methods in HSCT and patients with hematological malignancies, or to determine when empirical antifungal therapy can be withheld.

Problems related to antifungal prescription: a qualitative study of the views of intensivists

RATIONALE AND OBJECTIVE

The choice of the appropriate antifungal medication is essential for therapeutic success. Although guidelines are available in the literature that regulate the consistent use of antifungal, no previous qualitative studies have addressed the difficulties related to the use of antifungal medication, especially in the intensive care unit (ICU). Our objective was to qualitatively investigate how intensivists consider antifungal prescriptions in an adult ICU.

METHODS

The Grounded Theory analytical method was used for the data analysis. Physicians who worked in the adult ICU and prescribed antifungal medications were individually interviewed. A semi-structured interview was used to ask core questions, followed by follow-up questions at the discretion of the interviewer.

RESULTS

Our analysis generated eight main emerging themes that were classified into three related groups. The main insights were that various interconnected reasons were given for the lack of conformity with regard to prescription patterns for antifungals. A negative cycle was perceived based on issues related to prescriptions and the search for knowledge. If problems related to individual actions and multidisciplinary team integration are resolved and local protocols are implemented based on local epidemiology, then barriers to proper prescriptions can be overcome when intensivists are faced with the unusual practice of prescribing antifungals.

CONCLUSIONS

Our investigation indicates the need for prescription assistance with support from a well-trained multidisciplinary team and consensus among its members and the importance of well-designed protocols.

Prevalence of Invasive Aspergillosis Among (PTB) Patients in Kanchipuram, India

BACKGROUND

Tuberculosis (TB) remains a major health problem worldwide. (PTB) is commonly associated with secondary aspergilloma. Repeated exposure of Aspergillus spores can aggravate the bronchial pathology and can manifest as asthmatic episodes.

AIM AND OBJECTIVE

Pulmonary invasive aspergillosis is difficult to evaluate. Culture based diagnosis is time consuming. Hence (PCR) was done to evaluate the invasive fungal aspergillosis in (PTB) patients.

MATERIALS AND METHODS

Eighty sputum samples collected from TB patients were processed as per standard protocol. Species level identification was done using PCR.

RESULTS

Among 80 patients, 26 isolates were obtained, only 8 were Aspergillus species. All Aspergillus were taken up for PCR evaluation.

CONCLUSION

Fungal infection should be suspected in all sputum positive patients. PCR is an effective tool to diagnose invasive aspergillosis.

Molecular typing of Candida albicans isolates from hospitalized patients

SUMMARY

Introduction: The majority of nosocomial fungal infections are caused by Candida spp. where C. albicans is the species most commonly identified. Molecular methods are important tools for assessing the origin of the yeasts isolated in hospitals.

Methods: This is a study on the genetic profifiles of 39 nosocomial clinical isolates of C. albicans using two typing methods: random amplifified polymorphic DNA (RAPD) and microsatellite, two different primers for each technique were used.

Results: RAPD provided 10 and 11 different profiles with values for S_AB of 0.84 ± 0.126 and 0.88 ± 0.08 for primers M2 and P4, respectively. Microsatellite using two markers, CDC3 and HIS3, allowed the observation of six and seven different alleles, respectively, with combined discriminatory power of 0.91.

Conclusions: Although genetic variability is clear, it was possible to identify high similarity, suggesting a common origin for at least a part of isolates. It is important to emphasize that common origin was proven from yeasts isolated from colonization (urine, catheter or endotracheal secretions) and blood culture from the same patient, indicating that the candidemia must have started from a site of colonization. The combination of RAPD and microsatellite provides a quick and efficient analysis for investigation of similarity among nosocomial isolates of C. albicans.

Synthesis and antifungal activity of ASP9726, a novel echinocandin with potent Aspergillus hyphal growth inhibition

The synthesis and antifungal activity of ASP9726, a novel echinocandin with potent Aspergillus hyphal growth inhibition and significantly improved MIC against Candida parapsilosis and echinocandin resistant-Candida is described.

Extensive phytochemical investigation of the polar constituents of Diospyros bipindensis Gürke traditionally used by Baka pygmies

The water maceration and methanolic extract of the stem barks of Diospyros bipindensis, which is a medicinal plant used in Cameroon by Baka pygmies, revealed a complex high-performance liquid chromatography (HPLC) profile primarily composed of coumarin and naphthoquinone glycosides. The methanolic and apolar extracts also exhibited significant antifungal activity on a TLC bioautography assay against Candida albicans. HPLC-microfractionation in 96-well plates combined with bioautography enabled the rapid localization of the antifungal compound that was identified by HPLC-PDA and HPLC-MS analysis as plumbagin. These on-line structural information were also used to dereplicate four known compounds. The isolation of the polar constituents from the methanolic extract enabled the identification of eleven other compounds also present in the traditional preparation, nine of which are reported for the first time. The structures of those compounds were elucidated by UV, NMR and HR-MS analysis.

Antifungal application of nonantifungal drugs

Candida species are the cause of 60% of all mycoses in immunosuppressed individuals, leading to ∼150,000 deaths annually due to systemic infections, whereas the current antifungal therapies either have toxic side effects or are insufficiently efficient. We performed a screening of two compound libraries, the Enzo and the Institute for Molecular Medicine Finland (FIMM) oncology collection library, for anti-Candida activity based on the European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. From a total of 844 drugs, 26 agents showed activity against Candida albicans. Of those, 12 were standard antifungal drugs (SADs) and 7 were off-target drugs previously reported to be active against Candida spp. The remaining 7 off-target drugs, amonafide, tosedostat, megestrol acetate, melengestrol acetate, stanozolol, trifluperidol, and haloperidol, were identified with this screen. The anti-Candida activities of the new agents were investigated by three individual assays using optical density, ATP levels, and microscopy. The antifungal activities of these drugs were comparable to those of the SADs found in the screen. The aminopeptidase inhibitor tosedostat, which is currently in a clinical trial phase for anticancer therapy, displayed a broad antifungal activity against different Candida spp., including Candida glabrata. Thus, this screen reveals agents that were previously unknown to be anti-Candida agents, which allows for the design of novel therapies against invasive candidiasis.

Intermolecular interaction of voriconazole analogues with model membrane by DSC and NMR, and their antifungal activity using NMR based metabolic profiling

The development of novel antifungal agents with high susceptibility and increased potency can be achieved by increasing their overall lipophilicity. To enhance the lipophilicity of voriconazole, a second generation azole antifungal agent, we have synthesized its carboxylic acid ester analogues, namely p-methoxybenzoate (Vpmb), toluate (Vtol), benzoate (Vbz) and p-nitrobenzoate (Vpnb). The intermolecular interactions of these analogues with model membrane have been investigated using nuclear magnetic resonance (NMR) and differential scanning calorimetric (DSC) techniques. The results indicate varying degree of changes in the membrane bilayer's structural architecture and physico-chemical characteristics which possibly can be correlated with the antifungal effects via fungal membrane. Rapid metabolite profiling of chemical entities using cell preparations is one of the most important steps in drug discovery. We have evaluated the effect of synthesized analogues on Candida albicans. The method involves real time (1)H NMR measurement of intact cells monitoring NMR signals from fungal metabolites which gives Metabolic End Point (MEP). This is then compared with Minimum Inhibitory Concentration (MIC) determined using conventional methods. Results indicate that one of the synthesized analogues, Vpmb shows reasonably good activity.