-
Cells Nov 2023Candidiasis is a highly pervasive infection posing major health risks, especially for immunocompromised populations. Pathogenic species have evolved intrinsic and... (Review)
Review
Candidiasis is a highly pervasive infection posing major health risks, especially for immunocompromised populations. Pathogenic species have evolved intrinsic and acquired resistance to a variety of antifungal medications. The primary goal of this literature review is to summarize the molecular mechanisms associated with antifungal resistance in species. Resistance can be conferred via gain-of-function mutations in target pathway genes or their transcriptional regulators. Therefore, an overview of the known gene mutations is presented for the following antifungals: azoles (fluconazole, voriconazole, posaconazole and itraconazole), echinocandins (caspofungin, anidulafungin and micafungin), polyenes (amphotericin B and nystatin) and 5-fluorocytosine (5-FC). The following mutation hot spots were identified: (1) ergosterol biosynthesis pathway mutations (ERG11 and UPC2), resulting in azole resistance; (2) overexpression of the efflux pumps, promoting azole resistance (transcription factor genes: and ; transporter genes: CDR1, CDR2, MDR1, PDR16 and SNQ2); (3) cell wall biosynthesis mutations (FKS1, FKS2 and PDR1), conferring resistance to echinocandins; (4) mutations of nucleic acid synthesis/repair genes (FCY1, FCY2 and FUR1), resulting in 5-FC resistance; and (5) biofilm production, promoting general antifungal resistance. This review also provides a summary of standardized inhibitory breakpoints obtained from international guidelines for prominent species. Notably, , and demonstrate fluconazole resistance.
Topics: Antifungal Agents; Candida; Fluconazole; Echinocandins; Azoles
PubMed: 37998390
DOI: 10.3390/cells12222655 -
International Journal of Antimicrobial... Feb 2024The use of extracorporeal membrane oxygenation (ECMO) as a cardiocirculatory or respiratory support has tremendously increased in critically ill patients. In the setting...
BACKGROUND AND OBJECTIVE
The use of extracorporeal membrane oxygenation (ECMO) as a cardiocirculatory or respiratory support has tremendously increased in critically ill patients. In the setting of ECMO support, invasive fungal infections are a severe cause of morbidity and mortality. This vulnerable population is at risk of suboptimal antifungal exposure due to an increased volume of distribution (Vd), drug sequestration and decreased clearance. Here, we aimed to summarize ex-vivo and clinical studies on the potential impact of ECMO on the pharmacokinetics (PK) of antifungal agents and dosing requirements.
METHODS
A systematic search of the literature within electronic databases PubMed and EMBASE was conducted from database inception to 30 April 2023. Inclusion criteria were as follows: critically ill patients receiving ECMO regardless of age and reporting at least one PK parameter.
RESULTS
Thirty-six studies met inclusion criteria, including seven ex-vivo experiments and 29 clinical studies evaluating three classes of antifungals: polyenes, triazoles and echinocandins. Based on the available ex-vivo PK data, we found a significant sequestration of highly lipophilic and protein-bound antifungals within the ECMO circuit such as voriconazole, posaconazole and micafungin but the PK of several antifungals remains to be addressed such as amphotericin B, isavuconazole and anidulafungin. Most clinical studies have shown increased Vd of some antifungals like fluconazole and micafungin, particularly in the pediatric population. Conflicting data exist about caspofungin exposure.
CONCLUSIONS
The available literature on the antifungal PK changes in ECMO setting is scarce. Whenever possible, therapeutic drug monitoring is highly advised to personalize antifungal therapy.
Topics: Humans; Antifungal Agents; Caspofungin; Critical Illness; Extracorporeal Membrane Oxygenation; Micafungin
PubMed: 38161046
DOI: 10.1016/j.ijantimicag.2023.107078 -
The Journal of Infection Nov 2023The objectives of this study were to assess Candida spp. distribution and antifungal resistance of candidaemia across Europe. Isolates were collected as part of the...
The objectives of this study were to assess Candida spp. distribution and antifungal resistance of candidaemia across Europe. Isolates were collected as part of the third ECMM Candida European multicentre observational study, conducted from 01 to 07-07-2018 to 31-03-2022. Each centre (maximum number/country determined by population size) included ∼10 consecutive cases. Isolates were referred to central laboratories and identified by morphology and MALDI-TOF, supplemented by ITS-sequencing when needed. EUCAST MICs were determined for five antifungals. fks sequencing was performed for echinocandin resistant isolates. The 399 isolates from 41 centres in 17 countries included C. albicans (47.1%), C. glabrata (22.3%), C. parapsilosis (15.0%), C. tropicalis (6.3%), C. dubliniensis and C. krusei (2.3% each) and other species (4.8%). Austria had the highest C. albicans proportion (77%), Czech Republic, France and UK the highest C. glabrata proportions (25-33%) while Italy and Turkey had the highest C. parapsilosis proportions (24-26%). All isolates were amphotericin B susceptible. Fluconazole resistance was found in 4% C. tropicalis, 12% C. glabrata (from six countries across Europe), 17% C. parapsilosis (from Greece, Italy, and Turkey) and 20% other Candida spp. Four isolates were anidulafungin and micafungin resistant/non-wild-type and five resistant to micafungin only. Three/3 and 2/5 of these were sequenced and harboured fks-alterations including a novel L657W in C. parapsilosis. The epidemiology varied among centres and countries. Acquired echinocandin resistance was rare but included differential susceptibility to anidulafungin and micafungin, and resistant C. parapsilosis. Fluconazole and voriconazole cross-resistance was common in C. glabrata and C. parapsilosis but with different geographical prevalence.
PubMed: 37549695
DOI: 10.1016/j.jinf.2023.08.001 -
Mycoses Jan 2024Invasive fungal diseases (IFDs) play an important role in the supportive care of paediatric patients with acute leukaemia and those undergoing allogeneic haematopoietic... (Review)
Review
Invasive fungal diseases (IFDs) play an important role in the supportive care of paediatric patients with acute leukaemia and those undergoing allogeneic haematopoietic cell transplantation, and they are associated with significantly decreased overall survival rates in affected individuals. Relative to adults, children and adolescents are distinct in terms of host biology, predisposing conditions, presentation and epidemiology of fungal diseases, and in the pharmacology of antifungal agents. The paediatric development of antifungal agents has moved forward in a coordinated manner, and major advances have been made regarding concepts and recommendations for the prevention and treatment of IFDs. However, antifungal therapy is increasingly complex, and a solid knowledge of the available options is needed more than ever for successful management. This narrative review provides a summary of the paediatric development of agents that have been recently approved (anidulafungin, posaconazole) or are in advanced stages of development (isavuconazole). It also reviews the emerging evidence for the efficacy of echinocandins for prophylaxis of invasive aspergillosis, presents new data on alternative dosing regimens of echinocandins and voriconazole, and provides a brief overview of new antifungal agents in clinical development that are expected to be developed for paediatric patients.
Topics: Adolescent; Humans; Child; Antifungal Agents; Mycoses; Echinocandins; Anidulafungin; Invasive Fungal Infections
PubMed: 37789721
DOI: 10.1111/myc.13654 -
Mycoses Aug 2023Epidemiological knowledge is important to guide antifungal therapy.
BACKGROUND
Epidemiological knowledge is important to guide antifungal therapy.
OBJECTIVE
This multicentre study aimed to investigate the species distribution and antifungal susceptibility of Aspergillus isolates in Taiwan.
METHOD
Four hundred and ninety-two clinical Aspergillus isolates, collected during 2016-2020, were identified by calmodulin sequencing and tested for antifungal susceptibility using CLSI M38-A3. The Cyp51A sequences of azole-resistant Aspergillus fumigatus and Aspergillus flavus isolates were analysed.
RESULTS
This collection comprised 30 species from eight Aspergillus sections-Flavi (33.5%), Nigri (26.0%), Fumigati (24.2%), Terrei (10.0%), Nidulantes (5.1%), Circumdati (0.8%), Restricti (0.2%) and Aspergillus (0.2%). Sections Fumigati, Flavi and Terrei were primarily represented by A. fumigatus (99.2%), A. flavus (95.8%) and A. terreus (100%), respectively. Section Nigri comprised nine species, mostly A. welwitschiae (60.2%), A. niger (12.5%), A. brunneoviolaceus (10.9%) and A. tubingensis (10.2%). A. fumigatus (39.6%) and A. flavus (26.4%) predominated among 53 isolates from lower respiratory samples, whereas section Nigri species (46.2%) and A. terreus (29.2%) predominated among 65 isolates from ear samples. Reduced susceptibility to amphotericin B (minimal inhibitory concentration (MIC) > 1 μg/mL) was noted in A. flavus (7.0%), A. terreus (6.1%), A. nidulans and section Circumdati (A. flocculosus, A. subramanianii and A. westerdijkiae) isolates. Acquired azole resistance was observed in seven A. fumigatus (5.9%), all of which carried TR /L98H or TR /L98H/S297T/F495I mutation, and three A. flavus (1.9%), one of which carried G441S mutation. Reduced susceptibility to itraconazole (MIC >1 μg/mL) was noted in 55.5% of section Nigri isolates, mainly in A. welwitschiae, A. niger and A. tubingensis, whereas A. brunneoviolaceus, A. aculeatinus and A. japonicus were hypersusceptible to azoles. Anidulafungin was active against all isolates except for one isolate.
CONCLUSIONS
This study depicted the molecular epidemiology and species-specific characteristics of Aspergillus in Taiwan, which aids in appropriate antifungal therapy and underlines the need of speciation and susceptibility testing of disease-causing Aspergillus.
Topics: Humans; Antifungal Agents; Taiwan; Aspergillus; Itraconazole; Azoles; Aspergillus fumigatus; Microbial Sensitivity Tests; Drug Resistance, Fungal; Fungal Proteins
PubMed: 37186489
DOI: 10.1111/myc.13593 -
Microbial Genomics Jul 2023Invasive candida infections are significant infections that may occur in vulnerable patients with high rates of mortality or morbidity. Drug-resistance rates also appear...
Invasive candida infections are significant infections that may occur in vulnerable patients with high rates of mortality or morbidity. Drug-resistance rates also appear to be on the rise which further complicate treatment options and outcomes. The aims of this study were to describe the prevalence, molecular epidemiology, and genetic features of bloodstream isolates in a hospital setting. The resistance mechanisms towards the two most commonly administered antifungals, fluconazole and anidulafungin, were determined. Blood culture isolates between 1 January 2018 and 30 June 2021 positive for spp. were included. Susceptibility testing was performed using Etest. Whole-genome-sequencing was performed using Illumina NovaSeq with bioinformatics analysis performed. A total of 203 isolates were sequenced: 56 . 53 . , 44 . 36 . complex (consisting of and ), six . five . , and three . . A single cluster of azole-resistant and four clusters of isolates were observed, suggesting possible transmission occurring over several years. We found 11.3%, and 52.7 % of and , respectively, clustered with other isolates, suggesting exogenous sources may play a significant role of transmission, particularly for . The clusters spanned over several years suggesting the possibility of environmental reservoirs contributing to the spread. Limited clonality was seen for . Several sequence types appeared to be dominant for however the SNP differences varied widely, indicating absence of sustained transmission.
Topics: Humans; Tertiary Care Centers; Drug Resistance, Fungal; Antifungal Agents; Candidemia; Candida; Genomics
PubMed: 37440287
DOI: 10.1099/mgen.0.001047 -
Medical Mycology Jul 2023In vitro interactions between tacrolimus, a calcineurin inhibitor, and fluconazole, itraconazole, caspofungin, or anidulafungin were evaluated against Candida auris, C....
In vitro interactions between tacrolimus, a calcineurin inhibitor, and fluconazole, itraconazole, caspofungin, or anidulafungin were evaluated against Candida auris, C. albicans, C. parapsilosis, and C. glabrata (each five strains). Tacrolimus-itraconazole, tacrolimus-caspofungin, and tacrolimus-fluconazole combinations resulted in synergistic interactions against 95%, 90%, and 60% of Candida isolates, respectively. However, tacrolimus-anidulafungin resulted in only a 35% synergistic effect. A combination of tacrolimus and itraconazole was most potent with synergy against 100% of C. auris, C. parapsilosis, and C. glabrata isolates. Of note, no antagonistic interaction was found.
Topics: Animals; Antifungal Agents; Candida; Tacrolimus; Fluconazole; Candida auris; Caspofungin; Anidulafungin; Itraconazole; Echinocandins; Candida glabrata; Candida parapsilosis; Microbial Sensitivity Tests
PubMed: 37437917
DOI: 10.1093/mmy/myad069 -
Medizinische Klinik, Intensivmedizin... Sep 2023Invasive fungal infections caused by Candida or Aspergillus are associated with a high mortality. Knowledge about the risk factors, diagnosis and treatment management... (Review)
Review
BACKGROUND
Invasive fungal infections caused by Candida or Aspergillus are associated with a high mortality. Knowledge about the risk factors, diagnosis and treatment management is crucial for improving the survival of those affected.
OBJECTIVE
To give a practical overview about risk factors and treatment management of Candida and Aspergillus infections as well as providing an outlook on new antifungal agents.
MATERIAL AND METHODS
Summary of the relevant literature and recommendations on candidemia and invasive candidiasis as well as invasive and chronic pulmonary aspergillosis.
RESULTS
The first line treatment of candidemia and invasive candidiasis are echinocandins including caspofungin, anidulafungin and micafungin. Regular blood cultures have to be taken to determine the duration of treatment. After the first negative control blood culture treatment should be continued for another 14 days. The first line treatment of invasive pulmonary aspergillosis is azoles including voriconazole and isavuconazole. The duration of treatment depends on disease severity and is recommended for 6-12 weeks. The duration of treatment for chronic pulmonary aspergillosis is 6-12 months. Therapeutic drug monitoring is recommended for voriconazole and for posaconazole. New antifungal agents including olorofim, fosmanogepix, opelconazole, rezafungin or ibrexafungerp will broaden the therapeutic spectrum in the foreseeable future.
CONCLUSION
Knowledge about risk factors and the correct treatment management is crucial for the survival of patients with invasive fungal infections.
Topics: Humans; Antifungal Agents; Candida; Voriconazole; Candidemia; Aspergillus; Invasive Fungal Infections; Pulmonary Aspergillosis; Candidiasis, Invasive
PubMed: 37644243
DOI: 10.1007/s00063-023-01051-6 -
Microbial Biotechnology Jan 2024Invasive fungal infections have increased remarkably, which have become unprecedented concern to human health. However, the effectiveness of current antifungal drugs is... (Review)
Review
Invasive fungal infections have increased remarkably, which have become unprecedented concern to human health. However, the effectiveness of current antifungal drugs is limited due to drug resistance and toxic side-effects. It is urgently required to establish the effective biosynthetic strategy for developing novel and safe antifungal molecules economically. Echinocandins become a promising option as a mainstay family of antifungals, due to specifically targeting the fungal specific cell wall. To date, three kinds of echinocandins for caspofungin, anidulafungin, and micafungin, which derived from pneumocandin B , echinocandin B, and FR901379, are commercially available in clinic and have shown potential in managing invasive fungal infections in a cost-effective manner. However, current echinocandins-derived precursors all are produced by environmental fungal isolates with long fermentation cycle and low yields, which challenge the production efficacy of these precursors in industry. Therefore, understanding their biosynthetic machinery is of great importance for improving antifungal titres and creating new echinocandins-derived products. With the development of genome-wide sequencing and establishment of gene-editing technology, there are a growing number of reports on echinocandins-derived products and their biosynthetic gene clusters. This review briefly summarizes the discovery and development history of echinocandins, compares their structural characteristics and biosynthetic processes, and sums up existed strategies for improving their production. Moreover, the genomic analysis of related biosynthetic gene clusters of echinocandins is discussed, highlighting the similarities and differences among the clusters. Last, the biosynthetic processes of echinocandins are compared, focusing on the activation and attachment of side-chains and the formation of the hexapeptide core. This review aims to provide insights into the development and production of new echinocandin drugs by modifying the structure of echinocandin-derived precursors and/or optimizing the fermentation processes; and achieve a new microbial chassis for efficient production of echinocandins in heterologous hosts.
Topics: Humans; Antifungal Agents; Echinocandins; Fermentation; Invasive Fungal Infections; Microbial Sensitivity Tests; Lipopeptides
PubMed: 37885073
DOI: 10.1111/1751-7915.14359