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Journal of Fungi (Basel, Switzerland) Dec 2021In different regions worldwide, there exists an intra-and inter-regional variability in the rates of resistance to antifungal agents in , highlighting the importance of... (Review)
Review
In different regions worldwide, there exists an intra-and inter-regional variability in the rates of resistance to antifungal agents in , highlighting the importance of understanding the epidemiology and antifungal susceptibility profiles of in each region. However, in some regions, such as Ibero-America, limited data are available in this context. Therefore, in the present study, a systematic review was conducted to determine the antifungal resistance in in Ibero-America over the last five years. A literature search for articles published between January 2015 and December 2020 was conducted without language restrictions, using the PubMed, Embase, Cochrane Library, and LILACS databases. The search terms that were used were "" AND "antifungal resistance" AND "Country", and 22 publications were retrieved from different countries. The use of azoles (fluconazole, itraconazole, voriconazole, posaconazole, isavuconazole, ketoconazole, and miconazole) varied between 4.0% and 100%, and that of echinocandins (micafungin, caspofungin, and anidulafungin) between 1.1% and 10.0%. The limited information on this subject in the region of Ibero-America emphasizes the need to identify the pathogens at the species level and perform antifungal susceptibility tests that may lead to the appropriate use of these drugs and the optimal doses in order to avoid the development of antifungal resistance or multi-resistance.
PubMed: 35049954
DOI: 10.3390/jof8010014 -
Molecules (Basel, Switzerland) Jan 2023The use of essential oils is increasingly being investigated among new therapeutic approaches based on medicinal plants and their extracts. With the wide use of... (Review)
Review
The use of essential oils is increasingly being investigated among new therapeutic approaches based on medicinal plants and their extracts. With the wide use of synthetic and semi-synthetic antimicrobial drugs, the spread of drug-resistant clinical isolates has increased, and research is directed towards natural products, such as essential oils, as useful antimicrobial resources. In the context of a prospective infection, we compared the impact of essential oils and common antimicrobial agents on the microbicidal activity of human phagocytes. Here, we present the results of our decades-long investigation into the effectiveness of thyme red oil (26.52% thymol chemotype), tea tree oil (TTO), and Mentha of Pancalieri [( (Huds) var. (Sole), form (Camus) ()] essential oils on human polymorphonuclear leukocytes (PMNs) capacity to kill clinical strains of and when compared to three antifungal drugs used to treat candidiasis (fluconazole, anidulafungin, and caspofungin) These essential oils demonstrate antifungal drug-like and/or superior efficacy in enhancing intracellular killing by PMNs, even at subinhibitory concentrations. Our results are compared with data in the literature on essential oils and immune system interactions. This comparison would aid in identifying therapeutic solutions to the increasingly prevalent antibiotic resistance as well as filling in any remaining knowledge gaps on the bioactivity of essential oils.
Topics: Humans; Oils, Volatile; Antifungal Agents; Prospective Studies; Fluconazole; Plant Oils; Anti-Infective Agents; Microbial Sensitivity Tests
PubMed: 36615625
DOI: 10.3390/molecules28010435 -
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 -
Frontiers in Pharmacology 2022We aimed to estimate the risk of drug-induced liver injury (DILI) from various antifungal treatments with azoles and echinocandins causing in real-world practice. We...
We aimed to estimate the risk of drug-induced liver injury (DILI) from various antifungal treatments with azoles and echinocandins causing in real-world practice. We performed disproportionality and Bayesian analyses based on data from the first quarter in 2004 to the third quarter in 2021 in the Food and Drug Administration Adverse Event Reporting System to characterize the signal differences of antifungal drugs-related DILI. We also compared the onset time and mortality differences of different antifungal agents. A total of 2943 antifungal drugs-related DILI were identified. Affected patients tended to be aged >45 years (51.38%), with more males than females (49.03% vs. 38.09%). Antifungal drug-induced liver injury is most commonly reported with voriconazole (32.45%), fluconazole (19.37%), and itraconazole (14.51%). Almost all antifungal drugs were shown to be associated with DILI under disproportionality and Bayesian analyses. The intraclass analysis of correlation between different antifungal agents and DILI showed the following ranking: caspofungin (ROR = 6.12; 95%CI: 5.36-6.98) > anidulafungin (5.15; 3.69-7.18) > itraconazole (5.06; 4.58-5.60) > voriconazole (4.58; 4.29-4.90) > micafungin (4.53; 3.89-5.27) > posaconazole (3.99; 3.47-4.59) > fluconazole (3.19; 2.93-3.47) > ketoconazole (2.28; 1.96-2.64). The onset time of DILI was significantly different among different antifungal drugs ( < 0.0001), and anidulafungin result in the highest mortality rate (50.00%), while ketoconazole has the lowest mortality rate (9.60%). Based on the Food and Drug Administration Adverse Event Reporting System database, antifungal drugs are significantly associated with DILI, and itraconazole and voriconazole had the greatest risk of liver injury. Due to indication bias, more clinical studies are needed to confirm the safety of echinocandins.
PubMed: 35571077
DOI: 10.3389/fphar.2022.891336 -
Pharmaceutics Apr 2023is a multidrug-resistant pathogen against which echinocandins are the drug of choice. However, information on how the chitin synthase inhibitor nikkomycin Z influences...
is a multidrug-resistant pathogen against which echinocandins are the drug of choice. However, information on how the chitin synthase inhibitor nikkomycin Z influences the killing activities of echinocandins against is currently lacking. We determined the killing activities of anidulafungin and micafungin (0.25, 1, 8, 16 and 32 mg/L each) with and without nikkomycin Z (8 mg/L) against 15 isolates representing four clades (South Asian n = 5; East Asian n = 3; South African n = 3; South American n = 4, two of which were of environmental origin). Two and one isolates from the South Asian clade harbored mutations in the hot-spot 1 (S639Y and S639P) and 2 (R1354H) regions of the gene, respectively. The anidulafungin, micafungin and nikkomycin Z MIC ranges were 0.015-4, 0.03-4 and 2->16 mg/L, respectively. Anidulafungin and micafungin alone exerted weak fungistatic activity against wild-type isolates and the isolate with a mutation in the hot-spot 2 region of but was ineffective against the isolates with a mutation in the hot-spot 1 region. The nikkomycin Z killing curves were always similar to their respective controls. Twenty-two of sixty (36.7%) anidulafungin plus nikkomycin Z and twenty-four of sixty (40%) micafungin plus nikkomycin Z combinations produced at least 100-fold decreases in the CFUs (synergy), with a 41.7% and 20% fungicidal effect, respectively, against wild-type isolates. Antagonism was never observed. Similar results were found with the isolate with a mutation in hot-spot 2 of , but the combinations were ineffective against the two isolates with prominent mutations in hot-spot 1 of . The simultaneous inhibition of β-1,3 glucan and chitin synthases in wild-type isolates produced significantly greater killing rates than either drug alone. Further studies are warranted to verify the clinical efficacy of echinocandin plus nikkomycin Z combinations against echinocandin susceptible isolates.
PubMed: 37242607
DOI: 10.3390/pharmaceutics15051365 -
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 -
JAC-antimicrobial Resistance Sep 2021is the second leading fungal pathogen causing candidaemia and invasive candidiasis in Europe. This yeast is recognized for its rapid ability to acquire antifungal drug...
BACKGROUND
is the second leading fungal pathogen causing candidaemia and invasive candidiasis in Europe. This yeast is recognized for its rapid ability to acquire antifungal drug resistance.
OBJECTIVES
We systematically evaluated 176 isolates submitted to the German National Reference Center for Invasive Fungal Infections (NRZMyk) between 2015 and 2019 with regard to echinocandin and fluconazole susceptibility.
METHODS
Susceptibility testing was performed using a reference protocol (EUCAST) and a range of commercial assays. Hot spot regions of the echinocandin target genes were sequenced using Sanger sequencing.
RESULTS
In total, 84 of 176 isolates were initially classified as anidulafungin-resistant based on EUCAST testing. Of those, 71 harboured mutations in the glucan synthase encoding genes (13% in , 87% in 2). Significant differences in anidulafungin MICs were found between distinct mutation sites. 11 wild-type (WT) isolates initially classified as resistant exhibited anidulafungin MICs fluctuating around the interpretation breakpoint upon re-testing with multiple assays. Two WT isolates consistently showed high anidulafungin MICs and thus must be considered resistant despite the absence of target gene mutations. Over one-third of echinocandin-resistant strains displayed concomitant fluconazole resistance. Of those, isolates linked to bloodstream infection carrying a change at Ser-663 were associated with adverse clinical outcome.
CONCLUSIONS
Resistant strains are emerging in Germany. Phenotypic echinocandin testing can result in misclassification of susceptible strains. genotyping aids in detecting these strains, however, echinocandin resistance may occur despite a wild-type genotype.
PubMed: 34377983
DOI: 10.1093/jacamr/dlab122 -
Antimicrobial Agents and Chemotherapy Jun 2023Candida auris is an emerging, multidrug-resistant fungal pathogen that causes refractory colonization and life-threatening, invasive nosocomial infections. The high...
Candida auris is an emerging, multidrug-resistant fungal pathogen that causes refractory colonization and life-threatening, invasive nosocomial infections. The high proportion of C. auris isolates that display antifungal resistance severely limits treatment options. Combination therapies provide a possible strategy by which to enhance antifungal efficacy and prevent the emergence of further resistance. Therefore, we examined drug combinations using antifungals that are already in clinical use or are undergoing clinical trials. Using checkerboard assays, we screened combinations of 5-flucytosine and manogepix (the active form of the novel antifungal drug fosmanogepix) with anidulafungin, amphotericin B, or voriconazole against drug resistant and susceptible C. auris isolates from clades I and III. Fractional inhibitory concentration indices (FICI values) of 0.28 to 0.75 and 0.36 to 1.02 were observed for combinations of anidulafungin with manogepix or 5-flucytosine, respectively, indicating synergistic activity. The high potency of these anidulafungin combinations was confirmed using live-cell microfluidics-assisted imaging of the fungal growth. In summary, combinations of anidulafungin with manogepix or 5-flucytosine show great potential against both resistant and susceptible C. auris isolates.
Topics: Antifungal Agents; Anidulafungin; Flucytosine; Candida auris; Candida; Microbial Sensitivity Tests
PubMed: 37162367
DOI: 10.1128/aac.01645-22 -
Microbiology Spectrum Dec 2022The proposed life cycle of fungi in the genus Pneumocystis has typically included both an asexual cycle via binary fission and a sexual cycle. Until recently, the...
The proposed life cycle of fungi in the genus Pneumocystis has typically included both an asexual cycle via binary fission and a sexual cycle. Until recently, the strategy used for sexual replication was largely unknown, but genomic and functional assays now support a mode known as primary homothallism (self-fertilization). The question of whether an asexual cycle contributes to the growth of these fungi remains. Treatment of Pneumocystis pneumonia in immunosuppressed rodent models with the class of drugs known as echinocandins is challenging the historical concept of asexual replication. The echinocandins target 1,3-β-D-glucan (BG) synthesis resulting in death for most fungi. Because Pneumocystis species have both non-BG expressing life cycle stages (trophic forms) and BG-expressing asci, treatment with anidulafungin and caspofungin resulted in elimination of asci, with large numbers of non-BG expressing organisms remaining in the lungs. Transcriptional analyses of anidulafungin treated Pneumocystis murina-infected lungs indicated that these agents were blocking the sexual cycle. In the present study, we explored whether there was an asexual or alternative method of replication that could rescue P. murina survival and growth in the context of anidulafungin treatment. The effects of anidulafungin treatment on early events in the sexual cycle were investigated by RT-qPCR targeting specific mating genes, including , and . Results from the and gene expression studies clearly indicated there was no rescue by an asexual cycle, supporting these fungi's reliance on the sexual cycle for survival and growth. Dysregulation of mating-associated genes showed that anidulafungin induced effects early in the mating process. The concept of a sexually obligate fungus is unique among human fungal pathogens. This reliance can be exploited for drug development and here we show a proof of principle for this unusual target. Most human fungal pathogens eschew the mammalian environment with its battery of immune responses. Pneumocystis appear to have evolved to survive in such an environment, perhaps by using sexual replication to help in DNA repair and to introduce genetic variation in its major surface antigen family because the lung is the primary environment of these pathogens. The concept of primary homothallism fits well into its chosen ecosystem, with ready mating partners expressing both mating type receptors, and a sexual cycle that can introduce beneficial genetic variation without the need for outbreeding.
Topics: Animals; Anidulafungin; Echinocandins; Ecosystem; Pneumocystis; Pneumonia, Pneumocystis
PubMed: 36287071
DOI: 10.1128/spectrum.02906-22