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Annual Review of Microbiology Sep 2023is a multidrug-resistant fungal pathogen that presents a serious threat to global human health. Since the first reported case in 2009 in Japan, infections have been... (Review)
Review
is a multidrug-resistant fungal pathogen that presents a serious threat to global human health. Since the first reported case in 2009 in Japan, infections have been reported in more than 40 countries, with mortality rates between 30% and 60%. In addition, has the potential to cause outbreaks in health care settings, especially in nursing homes for elderly patients, owing to its efficient transmission via skin-to-skin contact. Most importantly, is the first fungal pathogen to show pronounced and sometimes untreatable clinical drug resistance to all known antifungal classes, including azoles, amphotericin B, and echinocandins. In this review, we explore the causes of the rapid spread of . We also highlight its genome organization and drug resistance mechanisms and propose future research directions that should be undertaken to curb the spread of this multidrug-resistant pathogen.
Topics: Humans; Aged; Candida; Candida auris; Antifungal Agents; Echinocandins; Amphotericin B
PubMed: 37406342
DOI: 10.1146/annurev-micro-032521-015858 -
The New England Journal of Medicine Mar 2022Cryptococcal meningitis is a leading cause of human immunodeficiency virus (HIV)-related death in sub-Saharan Africa. Whether a treatment regimen that includes a single... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Cryptococcal meningitis is a leading cause of human immunodeficiency virus (HIV)-related death in sub-Saharan Africa. Whether a treatment regimen that includes a single high dose of liposomal amphotericin B would be efficacious is not known.
METHODS
In this phase 3 randomized, controlled, noninferiority trial conducted in five African countries, we assigned HIV-positive adults with cryptococcal meningitis in a 1:1 ratio to receive either a single high dose of liposomal amphotericin B (10 mg per kilogram of body weight) on day 1 plus 14 days of flucytosine (100 mg per kilogram per day) and fluconazole (1200 mg per day) or the current World Health Organization-recommended treatment, which includes amphotericin B deoxycholate (1 mg per kilogram per day) plus flucytosine (100 mg per kilogram per day) for 7 days, followed by fluconazole (1200 mg per day) for 7 days (control). The primary end point was death from any cause at 10 weeks; the trial was powered to show noninferiority at a 10-percentage-point margin.
RESULTS
A total of 844 participants underwent randomization; 814 were included in the intention-to-treat population. At 10 weeks, deaths were reported in 101 participants (24.8%; 95% confidence interval [CI], 20.7 to 29.3) in the liposomal amphotericin B group and 117 (28.7%; 95% CI, 24.4 to 33.4) in the control group (difference, -3.9 percentage points); the upper boundary of the one-sided 95% confidence interval was 1.2 percentage points (within the noninferiority margin; P<0.001 for noninferiority). Fungal clearance from cerebrospinal fluid was -0.40 log colony-forming units (CFU) per milliliter per day in the liposomal amphotericin B group and -0.42 log CFU per milliliter per day in the control group. Fewer participants had grade 3 or 4 adverse events in the liposomal amphotericin B group than in the control group (50.0% vs. 62.3%).
CONCLUSIONS
Single-dose liposomal amphotericin B combined with flucytosine and fluconazole was noninferior to the WHO-recommended treatment for HIV-associated cryptococcal meningitis and was associated with fewer adverse events. (Funded by the European and Developing Countries Clinical Trials Partnership and others; Ambition ISRCTN number, ISRCTN72509687.).
Topics: AIDS-Related Opportunistic Infections; Administration, Oral; Africa South of the Sahara; Amphotericin B; Antifungal Agents; Drug Administration Schedule; Drug Therapy, Combination; Fluconazole; Flucytosine; HIV Infections; Meningitis, Cryptococcal
PubMed: 35320642
DOI: 10.1056/NEJMoa2111904 -
Nature Nov 2023Decades of previous efforts to develop renal-sparing polyene antifungals were misguided by the classic membrane permeabilization model. Recently, the clinically vital...
Decades of previous efforts to develop renal-sparing polyene antifungals were misguided by the classic membrane permeabilization model. Recently, the clinically vital but also highly renal-toxic small-molecule natural product amphotericin B was instead found to kill fungi primarily by forming extramembraneous sponge-like aggregates that extract ergosterol from lipid bilayers. Here we show that rapid and selective extraction of fungal ergosterol can yield potent and renal-sparing polyene antifungals. Cholesterol extraction was found to drive the toxicity of amphotericin B to human renal cells. Our examination of high-resolution structures of amphotericin B sponges in sterol-free and sterol-bound states guided us to a promising structural derivative that does not bind cholesterol and is thus renal sparing. This derivative was also less potent because it extracts ergosterol more slowly. Selective acceleration of ergosterol extraction with a second structural modification yielded a new polyene, AM-2-19, that is renal sparing in mice and primary human renal cells, potent against hundreds of pathogenic fungal strains, resistance evasive following serial passage in vitro and highly efficacious in animal models of invasive fungal infections. Thus, rational tuning of the dynamics of interactions between small molecules may lead to better treatments for fungal infections that still kill millions of people annually and potentially other resistance-evasive antimicrobials, including those that have recently been shown to operate through supramolecular structures that target specific lipids.
Topics: Animals; Humans; Mice; Amphotericin B; Antifungal Agents; Cells, Cultured; Cholesterol; Drug Resistance, Fungal; Ergosterol; Kidney; Kinetics; Microbial Sensitivity Tests; Mycoses; Polyenes; Serial Passage; Sterols; Time Factors
PubMed: 37938782
DOI: 10.1038/s41586-023-06710-4 -
Clinical Microbiology and Infection :... Nov 2020EUCAST has revised the definition of the susceptibility category I from 'Intermediate' to 'Susceptible, Increased exposure'. This implies that I can be used where the... (Review)
Review
BACKGROUND
EUCAST has revised the definition of the susceptibility category I from 'Intermediate' to 'Susceptible, Increased exposure'. This implies that I can be used where the drug concentration at the site of infection is high, either because of dose escalation or through other means to ensure efficacy. Consequently, I is no longer used as a buffer zone to prevent technical factors from causing misclassifications and discrepancies in interpretations. Instead, an Area of Technical Uncertainty (ATU) has been introduced for MICs that cannot be categorized without additional information as a warning to the laboratory that decision on how to act has to be made. To implement these changes, the EUCAST-AFST (Subcommittee on Antifungal Susceptibility Testing) reviewed all, and revised some, clinical antifungal breakpoints.
OBJECTIVES
The aim was to present an overview of the current antifungal breakpoints and supporting evidence behind the changes.
SOURCES
This document is based on the ten recently updated EUCAST rationale documents, clinical breakpoint and breakpoint ECOFF documents.
CONTENT
The following breakpoints (in mg/L) have been revised or established for Candida species: micafungin against C. albicans (ATU = 0.03); amphotericin B (S ≤/> R = 1/1), fluconazole (S ≤/> R = 2/4), itraconazole (S ≤/> R = 0.06/0.06), posaconazole (S ≤/> R = 0.06/0.06) and voriconazole (S ≤/> R = 0.06/0.25) against C. dubliniensis; fluconazole against C. glabrata (S ≤/> R = 0.001/16); and anidulafungin (S ≤/> R = 4/4) and micafungin (S ≤/> R = 2/2) against C. parapsilosis. For Aspergillus, new or revised breakpoints include itraconazole (ATU = 2) and isavuconazole against A. flavus (S ≤/> R = 1/2, ATU = 2); amphotericin B (S ≤/> R = 1/1), isavuconazole (S ≤ /> R = 1/2, ATU = 2), itraconazole (S ≤/> R = 1/1, ATU = 2), posaconazole (ATU = 0.25) and voriconazole (S ≤/> R = 1/1, ATU = 2) against A. fumigatus; itraconazole (S ≤/> R = 1/1, ATU = 2) and voriconazole (S ≤/> R = 1/1, ATU = 2) against A. nidulans; amphotericin B against A. niger (S ≤/> R = 1/1); and itraconazole (S ≤/> R = 1/1, ATU = 2) and posaconazole (ATU = 0.25) against A. terreus.
IMPLICATIONS
EUCAST-AFST has released ten new documents summarizing existing and new breakpoints and MIC ranges for control strains. A failure to adopt the breakpoint changes may lead to misclassifications and suboptimal or inappropriate therapy of patients with fungal infections.
Topics: Amphotericin B; Antifungal Agents; Aspergillus; Candida; Fluconazole; Itraconazole; Microbial Sensitivity Tests; Practice Guidelines as Topic; Triazoles; Voriconazole
PubMed: 32562861
DOI: 10.1016/j.cmi.2020.06.007 -
Clinical Infectious Diseases : An... Dec 2023Amphotericin B is the gold standard treatment for severe mycoses. A new orally delivered, less-toxic formulation of amphotericin has been developed. (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Amphotericin B is the gold standard treatment for severe mycoses. A new orally delivered, less-toxic formulation of amphotericin has been developed.
METHODS
In our randomized clinical trial, we tested oral lipid nanocrystal (LNC) amphotericin B (MAT2203, Matinas Biopharma) vs intravenous (IV) amphotericin for human immunodeficiency virus-associated cryptococcal meningitis in 4 sequential cohorts. Two pilot cohorts assessed safety and tolerability (n = 10 each), and 2 cohorts assessed efficacy with/without 2 IV loading doses (n = 40 each). The experimental arm received 1.8 g/d oral LNC amphotericin through 2 weeks with 100 mg/kg/d flucytosine, then 1.2 g/d LNC amphotericin through 6 weeks. The randomized control arm (n = 41) received 7 days of IV amphotericin with flucytosine, then 7 days of fluconazole 1200 mg/d. The primary end point was cerebrospinal fluid (CSF) early fungicidal activity (EFA).
RESULTS
We randomized 80 participants to oral LNC amphotericin + flucytosine with (n = 40) and without (n = 40) 2 IV loading doses and 41 control participants to IV amphotericin + flucytosine. Mean EFA was 0.40 log10 colony-forming units (CFU)/mL/d for all-oral LNC amphotericin, 0.42 log10 Cryptococcus CFU/mL/d for oral LNC amphotericin with IV loading doses, and 0.46 log10 CFU/mL/d for IV amphotericin controls. LNC amphotericin groups achieved 2-week CSF sterility in 63% (44 of 70) vs 68% (23 of 34) of controls. The 18-week survival was 85% (34 of 40) with all-oral LNC amphotericin, 90% (36 of 40) with oral LNC amphotericin given IV loading doses, and 85% (35 of 41) with IV amphotericin.Grade 3-4 laboratory adverse events occurred less frequently in LNC amphotericin groups (41%) than the IV amphotericin group (61%, P = .05), particularly for anemia (21% vs 44%; P = .01) and potassium (5% vs 17%; P = .04).
CONCLUSIONS
This new oral amphotericin B LNC formulation appears promising for cryptococcal meningitis with antifungal activity, similar survival, and less toxicity than IV amphotericin.
CLINICAL TRIALS REGISTRATION
NCT04031833.
Topics: Humans; Meningitis, Cryptococcal; Amphotericin B; Flucytosine; Drug Therapy, Combination; Antifungal Agents; Fluconazole; Vaccines; Lipids
PubMed: 37606364
DOI: 10.1093/cid/ciad440 -
The European Respiratory Journal Jun 2022In allergic bronchopulmonary aspergillosis (ABPA), prolonged nebulised antifungal treatment may be a strategy for maintaining remission. (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
In allergic bronchopulmonary aspergillosis (ABPA), prolonged nebulised antifungal treatment may be a strategy for maintaining remission.
METHODS
We performed a randomised, single-blind, clinical trial in 30 centres. Patients with controlled ABPA after 4-month attack treatment (corticosteroids and itraconazole) were randomly assigned to nebulised liposomal amphotericin-B or placebo for 6 months. The primary outcome was occurrence of a first severe clinical exacerbation within 24 months following randomisation. Secondary outcomes included the median time to first severe clinical exacerbation, number of severe clinical exacerbations per patient, ABPA-related biological parameters.
RESULTS
Among 174 enrolled patients with ABPA from March 2015 through July 2017, 139 were controlled after 4-month attack treatment and were randomised. The primary outcome occurred in 33 (50.8%) out of 65 patients in the nebulised liposomal amphotericin-B group and 38 (51.3%) out of 74 in the placebo group (absolute difference -0.6%, 95% CI -16.8- +15.6%; OR 0.98, 95% CI 0.50-1.90; p=0.95). The median (interquartile range) time to first severe clinical exacerbation was longer in the liposomal amphotericin-B group: 337 days (168-476 days) 177 days (64-288 days). At the end of maintenance therapy, total immunoglobulin-E and precipitins were significantly decreased in the nebulised liposomal amphotericin-B group.
CONCLUSIONS
In ABPA, maintenance therapy using nebulised liposomal amphotericin-B did not reduce the risk of severe clinical exacerbation. The presence of some positive secondary outcomes creates clinical equipoise for further research.
Topics: Amphotericin B; Antifungal Agents; Aspergillosis, Allergic Bronchopulmonary; Aspergillus; Humans; Single-Blind Method
PubMed: 34764182
DOI: 10.1183/13993003.02218-2021 -
The Journal of Antimicrobial... Nov 2022The discovery of amphotericin B, a polyene antifungal compound, in the 1950s, and the formulation of this compound in a liposomal drug delivery system, has resulted in...
The discovery of amphotericin B, a polyene antifungal compound, in the 1950s, and the formulation of this compound in a liposomal drug delivery system, has resulted in decades of use in systemic fungal infections. The use of liposomal amphotericin B formulation is referenced in many international guidelines for the treatment of fungal infections such as Aspergillus and cryptococcal disease and Candida infections, as well as other less common infections such as visceral leishmaniasis. With the development of liposomal amphotericin B, an improved therapeutic index could be achieved that allowed the attainment of higher drug concentrations in both the plasma and tissue while simultaneously lowering the toxicity compared with amphotericin B deoxycholate. In over 30 years of experience with this drug, a vast amount of information has been collected on preclinical and clinical efficacy against a wide variety of pathogens, as well as evidence on its toxicity. This article explores the history and nature of the liposomal formulation, the key clinical studies that developed the pharmacokinetic, safety and efficacy profile of the liposomal formulation, and the available microbiological data.
Topics: Humans; Amphotericin B; Antifungal Agents; Mycoses; Candidiasis; Liposomes
PubMed: 36426673
DOI: 10.1093/jac/dkac351 -
Clinical Microbiology Reviews Dec 2021Infections due to species are an acute threat to human health; members of the section are the most frequently occurring agents, but depending on the local... (Review)
Review
Infections due to species are an acute threat to human health; members of the section are the most frequently occurring agents, but depending on the local epidemiology, representatives of section or section are the second or third most important. species complex is of great interest, as it is usually amphotericin B resistant and displays notable differences in immune interactions in comparison to . The latest epidemiological surveys show an increased incidence of as well as an expanding clinical spectrum (chronic infections) and new groups of at-risk patients being affected. Hallmarks of these non- invasive mold infections are high potential for tissue invasion, dissemination, and possible morbidity due to mycotoxin production. We seek to review the microbiology, epidemiology, and pathogenesis of species complex, address clinical characteristics, and highlight the underlying mechanisms of amphotericin B resistance. Selected topics will contrast key elements of with . We provide a comprehensive resource for clinicians dealing with fungal infections and researchers working on pathogenesis, aiming to bridge the emerging translational knowledge and future therapeutic challenges on this opportunistic pathogen.
Topics: Amphotericin B; Antifungal Agents; Aspergillosis; Aspergillus; Aspergillus fumigatus; Humans; Microbial Sensitivity Tests
PubMed: 34190571
DOI: 10.1128/CMR.00311-20 -
The Journal of Antimicrobial... Nov 2022Most invasive fungal infections are opportunistic in nature but the epidemiology is constantly changing, with new risk groups being identified. Neutropenia is a...
Most invasive fungal infections are opportunistic in nature but the epidemiology is constantly changing, with new risk groups being identified. Neutropenia is a classical risk factor for fungal infections, while critically ill patients in the ICU are now increasingly at risk of yeast and mould infections. Factors to be considered when choosing antifungal treatment include the emergence of rarer fungal pathogens, the risk of resistance to azoles and echinocandins and the possibility of drug-drug interactions. Liposomal amphotericin B has retained its place in the therapeutic armamentarium based on its clinical profile: a broad spectrum of antifungal activity with a low risk of resistance, predictable pharmacokinetics with a rapid accumulation at the infection site (including biofilms), a low potential for drug-drug interactions and a low risk of acute and chronic treatment-limiting toxicities versus other formulations of amphotericin B. It is a suitable choice for the first-line empirical or pre-emptive treatment of suspected fungal infections in neutropenic haematology patients and is an excellent alternative for patients with documented fungal disease who can no longer tolerate or continue their first-line azole or echinocandin therapy, both in the haematology setting and in the ICU. Moreover, it is the first-line drug of choice for the treatment of invasive mucormycosis. Finally, liposomal amphotericin B is one of the few antifungal agents approved for use in children of all ages over 1 month and is included in paediatric-specific guidelines for the management of fungal disease.
Topics: Humans; Amphotericin B; Antifungal Agents; Azoles; Echinocandins; Neutropenia; Invasive Fungal Infections
PubMed: 36426672
DOI: 10.1093/jac/dkac352 -
BioMed Research International 2022Mucormycosis is one among the life-threatening fungal infections with high morbidity and mortality. It is an uncommon and rare infection targeting people with altered... (Review)
Review
Mucormycosis is one among the life-threatening fungal infections with high morbidity and mortality. It is an uncommon and rare infection targeting people with altered immunity. This lethal infection induced by fungi belonging to the Mucorales family is very progressive in nature. The incidence has increased in recent decades owing to the rise in immunocompromised patients. Disease management involves a multimodal strategy including early administration of drugs and surgical removal of infected tissues. Among the antifungals, azoles and amphotericin B remain the gold standard drugs of choice for initial treatment. The order Mucorales are developing a high level of resistance to the available systemic antifungal drugs, and the efficacy still remains below par. Deciphering the molecular mechanisms behind the antifungal resistance in Mucormycosis would add vital information to our available antifungal armamentarium and design novel therapies. Therefore, in this review, we have discussed the mechanisms behind Mucormycosis antifungal resistance. Moreover, this review also highlights the basic mechanisms of action of antifungal drugs and the resistance landscape which is expected to augment future treatment strategies.
Topics: Humans; Mucormycosis; Antifungal Agents; Amphotericin B; Mucorales; Azoles
PubMed: 36277891
DOI: 10.1155/2022/6722245