RESUMO
Naturally occurring echinocandin B and FR901379 are potent antifungal lipopeptides featuring a cyclic hexapeptide nucleus and a fatty acid side chain. They are the parent compounds of echinocandin drugs for the treatment of severe fungal infections caused by the Candida and Aspergilla species. To minimize hemolytic toxicity, the native fatty acid side chains in these drug molecules are replaced with designer acyl side chains. The deacylation of the N-acyl side chain is, therefore, a crucial step for the development and manufacturing of echinocandin-type antibiotics. Echinocandin E (ECE) is a novel echinocandin congener with enhanced stability generated via the engineering of the biosynthetic machinery of echinocandin B (ECB). In the present study, we report the discovery of the first echinocandin E acylase (ECEA) using the enzyme similarity tool (EST) for enzymatic function mining across protein families. ECEA is derived from Streptomyces sp. SY1965 isolated from a sediment collected from the Mariana Trench. It was cloned and heterologously expressed in S. lividans TK24. The resultant TKecea66 strain showed efficient cleavage activity of the acyl side chain of ECE, showing promising applications in the development of novel echinocandin-type therapeutics. Our results also provide a showcase for harnessing the essentially untapped biodiversity from the hadal ecosystems for the discovery of functional molecules.
Assuntos
Antifúngicos , Equinocandinas , Streptomyces , Streptomyces/enzimologia , Streptomyces/genética , Equinocandinas/química , Antifúngicos/farmacologia , Antifúngicos/química , Amidoidrolases/metabolismo , Proteínas FúngicasRESUMO
Actinoplanes utahensis deacylase (AAC)-catalyzed deacylation of echinocandin B (ECB) is a promising method for the synthesis of anidulafungin, the newest of the echinocandin antifungal agents. However, the low activity of AAC significantly limits its practical application. In this work, we have devised a multi-dimensional rational design strategy for AAC, conducting separate analyses on the substrate-binding pocket's volume, curvature, and length. Furthermore, we quantitatively analyzed substrate properties, particularly on hydrophilic and hydrophobic. Accordingly, we tailored the linoleic acid-binding pocket of AAC to accommodate the extended long lipid chain of ECB. By fine-tuning the key residues, the resulting AAC mutants can accommodate the ECB lipid chain with a lower curvature binding pocket. The D53A/I55F/G57M/F154L/Q661L mutant (MT) displayed 331 % higher catalytic efficiency than the wild-type (WT) enzyme. The MT product conversion was 94.6 %, reaching the highest reported level. Utilizing a multi-dimensional rational design for a customized mutation strategy of the substrate-binding pocket is an effective approach to enhance the catalytic efficiency of enzymes in handling complicated substrates.
Assuntos
Equinocandinas , Proteínas Fúngicas , Interações Hidrofóbicas e Hidrofílicas , Equinocandinas/química , Especificidade por Substrato , Sítios de Ligação , Mutação , Modelos Moleculares , Amidoidrolases/química , Amidoidrolases/genética , Amidoidrolases/metabolismo , Ligação ProteicaRESUMO
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 B0 , 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.
Assuntos
Antifúngicos , Infecções Fúngicas Invasivas , Humanos , Antifúngicos/química , Equinocandinas/química , Fermentação , Infecções Fúngicas Invasivas/tratamento farmacológico , Testes de Sensibilidade Microbiana , LipopeptídeosRESUMO
Echinocandin B (ECB) is the key precursor compound of the antifungal drug Anidulafungin. The effects of the five precursor amino acids on ECB biosynthesis were firstly investigated. It showed that although L-threonine was a main compound of the hexapeptide scaffold of ECB, exogenous addition of L-threonine had no significant effect on the increase of ECB fermentation titer. Meanwhile, the ECB fermentation titer with methyl oleate showed two times higher than that of the other carbon sources. Transcription level analysis of the key genes for ECB biosynthesis indicated that the gene an655543 related to L-threonine biosynthesis showed higher value during the fermentation process, therefore, the exogenous addition of L-threonine had no obvious affection. Furthermore, it indicated that the transcription level of gene ecdA might be the main restriction factor for the ECB biosynthesis. The study provided the research foundation for the modification of the ECB producing strains in the following work.
Assuntos
Antifúngicos , Equinocandinas , Fermentação , Equinocandinas/genética , Equinocandinas/química , Antifúngicos/farmacologia , Antifúngicos/químicaRESUMO
The hydroxyl groups in the amino acid residues of echinocandin B were related to the biological activity, the instability, and the drug resistance. The modification of hydroxyl groups was expected to obtain the new lead compounds for next generation of echinocandin drug development. In this work one method for heterologous production of the tetradeoxy echinocandin was achieved. A reconstructed biosynthetic gene cluster for tetradeoxy echinocandins composed of ecdA/I/K and htyE was designed and successfully hetero-expressed in Aspergillus nidulans. The target product of echinocandin E (1) together with one unexpected derivative echinocandin F (2), were isolated from the fermentation culture of engineered strain. Both of compounds were unreported echinocandin derivatives and the structures were identified on the basis of mass and NMR spectral data analysis. Compared with echinocandin B, echinocandin E demonstrated superior stability and comparable antifungal activity.
Assuntos
Aspergillus nidulans , Equinocandinas , Equinocandinas/farmacologia , Equinocandinas/química , Equinocandinas/genética , Antifúngicos/farmacologia , Antifúngicos/metabolismo , Proteínas Fúngicas/metabolismo , Aspergillus nidulans/genética , Aspergillus nidulans/metabolismo , Família Multigênica , Aminoácidos/metabolismo , Testes de Sensibilidade MicrobianaRESUMO
The compound FR901379, a sulfated echinocandin produced by the filamentous fungus Coleophoma empetri F-11899, is an important intermediate for the synthesis of the antifungal drug micafungin. In this study, we established an efficient clustered regularly interspaced short palindromic repeats/Cas9-based gene editing tool for the industrial production strain C. empetri SIPI1284. With this method, the efficiency of gene mutagenesis in the target locus is up to 84%, which enables the rapid gene disruption for the analysis of FR901379 biosynthetic genes. Next, we verified the putative functional genes of the FR901379 biosynthetic gene cluster via gene disruption and gene complementation in vivo. These core functional genes included the nonribosomal peptide synthetase gene (CEnrps), the fatty-acyl-AMP ligase gene (CEligase) responsible for the formation of the activated form of palmitic acid and its transfer to CEnrps, four nonheme mononuclear iron oxygenase genes (CEoxy1, CEoxy2, CEoxy3, and CEoxy4) responsible for the synthesis of nonproteinogenic amino acids, l-homotyrosine biosynthesis genes (CEhtyA-D), two cytochrome P450 enzyme genes (CEp450-1 and CEp450-2), and a transcription regulator gene (CEhyp). In addition, by screening the whole genome, we identified two unknown genes (CEp450-3 and CEsul) responsible for the sulfonyloxy group of FR901379, which were separated from the core FR901379 biosynthetic cluster. Furthermore, during gene disruptions in the research, we obtained a series of FR901379 analogues and elucidated the relationship between the groups and antifungal activities.
Assuntos
Antifúngicos , Sistemas CRISPR-Cas , Antifúngicos/química , Ascomicetos , Sistemas CRISPR-Cas/genética , Equinocandinas/química , Genômica , Peptídeos Cíclicos , Tirosina/análogos & derivadosRESUMO
With increasing number of immunocompromised patients as well as drug resistance in fungi, the risk of fatal fungal infections in humans increases as well. The action of echinocandins is based on the inhibition of ß-(1,3)-d-glucan synthesis that builds the fungal cell wall. Caspofungin, micafungin, anidulafungin and rezafungin are semi-synthetic cyclic lipopeptides. Their specific chemical structure possess a potential to obtain novel derivatives with better pharmacological properties resulting in more effective treatment, especially in infections caused by Candida and Aspergillus species. In this review we summarise information about echinocandins with closer look on their chemical structure, mechanism of action, drug resistance and usage in clinical practice. We also introduce actual trends in modification of this antifungals as well as new methods of their administration, and additional use in viral and bacterial infections.
Assuntos
Antifúngicos/farmacologia , Aspergillus/efeitos dos fármacos , Candida/efeitos dos fármacos , Desenho de Fármacos , Equinocandinas/farmacologia , Antifúngicos/química , Aspergillus/metabolismo , Candida/metabolismo , Parede Celular/efeitos dos fármacos , Parede Celular/metabolismo , Equinocandinas/química , Glucanos/antagonistas & inibidores , Glucanos/metabolismo , Testes de Sensibilidade Microbiana , Estrutura MolecularRESUMO
Presently, echinocandins have been recommended as the first-line drugs for the treatment of invasive candidiasis. However, low oral bioavailability and solubility limit their application. To improve this situation, this study chose amino acid and fatty acid as raw materials to modify the nucleus of echinocandin B. Six N-acylated analogs were screened from the derivatives that possessed potent antifungal activity and good water solubility. Based on antifungal susceptibility and hemolytic toxicity, compound 5 as the candidate had good antifungal activity and no hemolytic effect. Moreover, compared with anidulafungin, compound 5 showed a comparable fungicidal effect, much higher solubility, and lower toxicity. In conclusion, compound 5 has the potential for further research and development on account of reserved antifungal activity, high solubility, and low toxicity.
Assuntos
Candida albicans/efeitos dos fármacos , Equinocandinas/farmacologia , Equinocandinas/toxicidade , Proteínas Fúngicas/farmacologia , Proteínas Fúngicas/toxicidade , Macrófagos/efeitos dos fármacos , Acilação , Animais , Antifúngicos , Peso Corporal/efeitos dos fármacos , Equinocandinas/química , Proteínas Fúngicas/química , Masculino , Camundongos , Camundongos Endogâmicos ICR , Testes de Sensibilidade Microbiana , Estrutura Molecular , Células RAW 264.7 , SolubilidadeRESUMO
Glarea lozoyensis is an important industrial fungus that produces the pneumocandin B0, which is used for the synthesis of antifungal drug caspofungin. However, because of the limitations and complications of traditional genetic tools, G. lozoyensis strain engineering has been hindered. In this study, we established an efficient CRISPR/Cas9-based gene editing tool in G. lozoyensis SIPI1208. With this method, gene mutagenesis efficiency in the target locus can be up to 80%, which enables the rapid gene knockout. According to the reports, GloF and Ap-HtyE, proline hydroxylases involved in pneumocandin and Echinocandin B biosynthesis, respectively, can catalyze the proline to generate different ratios of trans-3-hydroxy-l-proline to trans-4-hydroxy-l-proline. Heterologous expression of Ap-HtyE in G. lozoyensis decreased the ratio of pneumocandin C0 to (pneumocandin B0 + pneumocandin C0) from 33.5% to 11% without the addition of proline to the fermentation medium. Furthermore, the gloF was replaced by ap-htyE to study the production of pneumocandin C0. However, the gene replacement has been hampered by traditional gene tools since gloF and gloG, two contiguous genes indispensable in the biosynthesis of pneumocandins, are cotranscribed into one mRNA. With the CRISPR/Cas9 strategy, ap-htyE was knocked in and successfully replaced gloF, and results showed that the knock-in strain retained the ability to produce pneumocandin B0, but the production of pneumocandin C0 was abolished. Thus, this strain displayed a competitive advantage in the industrial production of pneumocandin B0. In summary, this study showed that the CRISPR/Cas9-based gene editing tool is efficient for manipulating genes in G. lozoyensis.
Assuntos
Ascomicetos/genética , Sistemas CRISPR-Cas/genética , Proteínas Fúngicas/genética , Edição de Genes/métodos , Equinocandinas/biossíntese , Equinocandinas/química , Proteínas Fúngicas/metabolismo , Mutagênese Sítio-Dirigida , Prolil Hidroxilases/genética , Prolil Hidroxilases/metabolismo , RNA Guia de Cinetoplastídeos/metabolismoRESUMO
Echinocandin B (ECB) is a key precursor of antifungal agent Anidulafungin, which has demonstrated clinical efficacy in patients with invasive candidiasis. In this study, the effects of microparticle-enhanced cultivation and methyl oleate on echinocandin B fermentation titer were investigated. The results showed that the titer was significantly influenced by the morphological type of mycelium, and mycelium pellet was beneficial to improve the titer of this secondary metabolism. First, different carbon sources were chosen for the fermentation, and methyl oleate achieved the highest echinocandin B titer of 2133 ± 50 mg/L, which was two times higher than that of the mannitol. The study further investigated the metabolic process of the fermentation, and the results showed that L-threonine concentration inside the cell could reach 275 mg/L at 168 h with methyl oleate, about 2.5 times higher than that of the mannitol. Therefore, L-threonine may be a key precursor of echinocandin B. In the end, a new method of adding microparticles for improving the mycelial morphology was used, and the addition of talcum powder (20 g/L, diameter of 45 µm) could make the maximum titer of echinocandin B reach 3148 ± 100 mg/L.
Assuntos
Equinocandinas/química , Fermentação/efeitos dos fármacos , Proteínas Fúngicas/química , Manitol/química , Ácidos Oleicos/química , Treonina/química , Aspergillus nidulans , Candidíase/tratamento farmacológico , Carbono/química , Meios de Cultura , Microesferas , Micélio/metabolismo , Talco/química , ViscosidadeRESUMO
New strategies are urgently needed to counter the threat to human health posed by drug-resistant fungi. To explore an as-yet unexploited target space for antifungals, we screened a library of protein kinase inhibitors for the ability to reverse resistance of the most common human fungal pathogen, Candida albicans, to caspofungin, a widely used antifungal. This screen identified multiple 2,3-aryl-pyrazolopyridine scaffold compounds capable of restoring caspofungin sensitivity. Using chemical genomic, biochemical, and structural approaches, we established the target for our most potent compound as Yck2, a casein kinase 1 family member. Combination of this compound with caspofungin eradicated drug-resistant C. albicans infection while sparing co-cultured human cells. In mice, genetic depletion of YCK2 caused an â¼3-log10 decline in fungal burden in a model of systemic caspofungin-resistant C. albicans infection. Structural insights and our tool compound's profile in culture support targeting the Yck2 kinase function as a broadly active antifungal strategy.
Assuntos
Candida albicans/efeitos dos fármacos , Candidíase/tratamento farmacológico , Farmacorresistência Fúngica/efeitos dos fármacos , Proteínas Fúngicas/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Animais , Antifúngicos/química , Antifúngicos/farmacologia , Células Cultivadas , Equinocandinas/química , Equinocandinas/farmacologia , Proteínas Fúngicas/metabolismo , Humanos , Camundongos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Inibidores de Proteínas Quinases/químicaRESUMO
Echinocandin B deacylase (EBDA), from Actinoplanes utahensis ZJB-08196, is capable of cleaving the linoleoyl group from echinocandin B (ECB), forming the echinocandin B nucleus (ECBN), which is a key precursor of semisynthetic antifungal antibiotics. In the present study, molecular evolution of AuEBDA by random mutagenesis combined with site-directed mutagenesis (SDM) and screening was performed. Random mutagenesis on the wild-type (WT) AuEBDA generated two beneficial substitutions of G287Q, R527V. The "best" variant AuEBDA-G287Q/R527V was obtained by combining G287Q with R527V through SDM, which was most active at 35 °C, pH 7.5, with Km and vmax values of 0.68 mM and 395.26 U/mg, respectively. Mutation of G287Q/R527V markedly increased the catalytic efficiency kcat/Km by 290% compared with the WT-AuEBDA.
Assuntos
Actinoplanes/enzimologia , Amidoidrolases/genética , Antifúngicos/farmacologia , Equinocandinas/química , Proteínas Fúngicas/química , Mutagênese Sítio-Dirigida , Catálise , Escherichia coli/enzimologia , Escherichia coli/genética , Biblioteca Gênica , Concentração de Íons de Hidrogênio , Cinética , Mutação , Streptomyces lividans/genética , TemperaturaRESUMO
Fungal diseases are a global public health problem. Invasive fungal infections pose a serious threat to patients with compromised immune systems, such as those undergoing organ or bone marrow transplants, cancer, or HIV/AIDS. Pneumocandins are antifungal lipohexapeptides of the echinocandin family that noncompetitively inhibit of 1,3-ß-glucan synthase of fungal cell wall and provide the precursor for the semisynthesis of caspofungin, which is widely used as first-line therapy for invasive fungal infections. Recently, the biosynthetic steps leading to formation of pneumocandin B0 and echinocandin B have been elucidated, and thus, provide a framework and attractive model for further design new antifungal therapeutics around natural variations in echinocandin structural diversities via genetic and chemical tools. In this article, we analyze the biosynthetic pathway of pneumocandins and other echinocandins, provide an update on the array of pneumocandin analogues generated by genetic manipulation, and summarize advances in the enhancement of pneumocandin B0 production by random mutagenesis and fermentation optimization. We also give offer advice on the development of improved pneumocandin drug candidates and more efficient production of pneumocandin B0.
Assuntos
Equinocandinas/biossíntese , Equinocandinas/farmacologia , Fungos/metabolismo , Antifúngicos/química , Antifúngicos/farmacologia , Vias Biossintéticas , Equinocandinas/química , Fermentação , Proteínas Fúngicas/biossíntese , Proteínas Fúngicas/química , Proteínas Fúngicas/farmacologia , Microbiologia IndustrialRESUMO
Secondary metabolites of microorganisms have proven to be an excellent source of drugs. We isolated a new antibiotic, named pestiocandin (1), from a culture broth of a filamentous fungus, Pestalotiopsis humus FKI-7473, using a multidrug-sensitive budding yeast, S. cerevisiae 12geneΔ0HSR-iERG6. The structure of 1 was elucidated by various NMR studies. All geometric isomerisms of 1 were shown to be the E-form and two pyranose units of 1 were found to be glucose and galactose types. Compound 1 showed weak growth inhibition against Gram-positive and Gram-negative bacteria, yeasts and a filamentous fungus. It displayed more potent growth inhibition against multidrug-sensitive yeasts than wild-type yeasts.
Assuntos
Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Ascomicetos/química , Aminoglicosídeos/química , Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Farmacorresistência Fúngica , Equinocandinas/química , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Saccharomyces cerevisiae , Estereoisomerismo , Leveduras/efeitos dos fármacosRESUMO
BACKGROUND/AIMS: To determine adsorption and transmembrane clearances (CLTM) of rezafungin, a novel long-acting echinocandin, in continuous venovenous hemofiltration (CVVH). METHODS: A validated ex vivo bovine blood CVVH model using polysulfone and AN69 hemodiafilters was used to evaluate urea and rezafungin CLTM at 3 different ultrafiltrate flow rates. Rezafungin adsorption to the CRRT apparatus was determined for each hemodiafilter. RESULTS: The sieving coefficient (SC) from CVVH with 3 different ultrafiltrate flow rates was 0 for both HF1400 and Multiflow-150 hemodiafilters, while urea SC was approximately 1 at all flow rates. Hemodiafilter type and ultrafiltrate flow rate did not influence CLTM. Rezafungin adsorption to the CVVH apparatus was not observed for either hemodiafilter. CONCLUSION: Rezafungin is not removed by CVVH by membrane adsorption or via CLTM. Ultrafiltrate flow rates and hemodiafilter types are unlikely to influence rezafungin CLTM. No dosage adjustment of rezafungin is likely required for critically ill patients receiving CVVH.
Assuntos
Equinocandinas/química , Hemodiafiltração/instrumentação , Membranas Artificiais , Adsorção , Hemodiafiltração/métodos , HumanosRESUMO
Cryptococcosis is one of the major invasive fungal infections distributed worldwide with high mortality rate. C. neoformans and C. gattii are the major organisms that cause various types of infections. Anti-fungal resistances exhibited by the mentioned species of Cryptococcus threaten their effective prevention and treatment. There is limited information available on human to human transmission of the pathogen and virulent factors that are responsible for Cryptococcus mediated infections. Hence, there is high scope for understanding the mechanism, probable drug targets and scope of developing natural therapeutic agents that possess high relevance to pharmaceutical biotechnology and medicinal chemistry. The proposed review illustrates the role of computer-aided virtual screening for the screening of probable drug targets and identification of natural lead candidates as therapeutic remedies. The review initially focuses on the current perspectives on cryptococcosis, major metabolic pathways responsible for the pathogenesis, conventional therapies and associated drug resistance, challenges and scope of structure-based drug discovery. The review further illustrates various approaches for the prediction of unknown drug targets, molecular modeling works, screening of natural compounds by computational virtual screening with ideal drug likeliness and pharmacokinetic features, application of molecular docking studies and simulation. Thus, the present review probably provides AN insight into the role of medicinal chemistry and computational drug discovery to combat Cryptococcus infections and thereby open a new paradigm for the development of novel natural therapeutic against various drug targets for cryptococcal infections.
Assuntos
Antifúngicos/farmacologia , Produtos Biológicos/farmacologia , Desenho Assistido por Computador , Cryptococcus gattii/efeitos dos fármacos , Cryptococcus neoformans/efeitos dos fármacos , Desenho de Fármacos , Animais , Antifúngicos/química , Azóis/química , Azóis/farmacologia , Produtos Biológicos/química , Criptococose/diagnóstico , Criptococose/tratamento farmacológico , Avaliação Pré-Clínica de Medicamentos , Equinocandinas/química , Equinocandinas/farmacologia , Humanos , Modelos Moleculares , Polienos/química , Polienos/farmacologiaRESUMO
Disruption of fungal cell wall should be an effective intervention strategy. However, the cell wall-disrupting echinocandin drugs, such as caspofungin (CAS), cannot exterminate filamentous fungal pathogens during treatment. For potency improvement of cell wall-disrupting agents (CAS, octyl gallate (OG)), antifungal efficacy of thirty-three cinnamic acid derivatives was investigated against Saccharomyces cerevisiaeslt2Δ, bck1Δ, mutants of the mitogen-activated protein kinase (MAPK), and MAPK kinase kinase, respectively, in cell wall integrity system, and glr1Δ, mutant of CAS-responsive glutathione reductase. Cell wall mutants were highly susceptible to four cinnamic acids (4-chloro-α-methyl-, 4-methoxy-, 4-methyl-, 3-methylcinnamic acids), where 4-chloro-α-methyl- and 4-methylcinnamic acids possessed the highest activity. Structure-activity relationship revealed that 4-methylcinnamic acid, the deoxygenated structure of 4-methoxycinnamic acid, overcame tolerance of glr1Δ to 4-methoxycinnamic acid, indicating the significance of para substitution of methyl moiety for effective fungal control. The potential of compounds as chemosensitizers (intervention catalysts) to cell wall disruptants (viz., 4-chloro-α-methyl- or 4-methylcinnamic acids + CAS or OG) was assessed according to Clinical Laboratory Standards Institute M38-A. Synergistic chemosensitization greatly lowers minimum inhibitory concentrations of the co-administered drug/agents. 4-Chloro-α-methylcinnamic acid further overcame fludioxonil tolerance of Aspergillus fumigatus antioxidant MAPK mutants (sakAΔ, mpkCΔ). Collectively, 4-chloro-α-methyl- and 4-methylcinnamic acids possess chemosensitizing capability to augment antifungal efficacy of conventional drug/agents, thus could be developed as target-based (i.e., cell wall disruption) intervention catalysts.
Assuntos
Antifúngicos/farmacologia , Parede Celular/efeitos dos fármacos , Cinamatos/farmacologia , Fungos/efeitos dos fármacos , Antifúngicos/química , Caspofungina , Parede Celular/química , Cinamatos/química , Dioxóis/farmacologia , Tolerância a Medicamentos/genética , Equinocandinas/química , Fungos/patogenicidade , Lipopeptídeos/química , Quinases de Proteína Quinase Ativadas por Mitógeno/genética , Mutação , Pirróis/farmacologia , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Relação Estrutura-AtividadeAssuntos
Estado Terminal/classificação , Equinocandinas/química , Lipopeptídeos/química , Obesidade Mórbida/sangue , Antifúngicos/efeitos adversos , Antifúngicos/química , Antifúngicos/uso terapêutico , Candidíase , Caspofungina , Estado Terminal/epidemiologia , Equinocandinas/efeitos adversos , Equinocandinas/uso terapêutico , Humanos , Unidades de Terapia Intensiva/organização & administração , Lipopeptídeos/efeitos adversos , Lipopeptídeos/uso terapêutico , Masculino , Pessoa de Meia-Idade , Obesidade Mórbida/complicações , Choque SépticoRESUMO
Background: The novel echinocandin CD101 has stability properties amenable to topical formulation for use in the treatment of acute vulvovaginal candidiasis (VVC) and recurrent VVC (RVVC). CD101 has demonstrated potent antifungal activity at pH 7, but assessment of its activity at the physiological pH of the vaginal environment is needed. Objectives: To evaluate the antifungal activity of CD101 against clinical VVC isolates of Candida spp., including azole-resistant strains, at pH 4. Methods: MIC values of CD101 and comparators (fluconazole, itraconazole, micafungin, caspofungin and anidulafungin) were assessed via broth microdilution. MIC assays were conducted at pH 7 and 4 after 24 and 48 h against a 108 VVC isolate panel of Candida spp., including Candida albicans ( n = 60), Candida glabrata ( n = 21), Candida parapsilosis ( n = 14) and Candida tropicalis ( n = 13). Results: Overall, MIC values of all drugs were slightly higher at pH 4 versus 7 and at 48 versus 24 h of incubation. CD101 MIC values typically exhibited â¼4-fold shifts at pH 4 and were not affected by azole susceptibility. C. parapsilosis susceptibility was the least affected at pH 4 and did not increase for most drugs. Conclusions: CD101 had potent activity against all Candida isolates tested, including azole-resistant strains. Although there was some reduction in activity at pH 4 versus 7, the resulting MIC values were still well below the intravaginal CD101 drug concentrations anticipated to be present following topical administration. These results support continued development of topical CD101 for the treatment of VVC/RVVC.
Assuntos
Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Candidíase Vulvovaginal/microbiologia , Equinocandinas/farmacologia , Azóis/farmacologia , Candida/isolamento & purificação , Candida albicans/efeitos dos fármacos , Candida albicans/isolamento & purificação , Candida glabrata/efeitos dos fármacos , Candida glabrata/isolamento & purificação , Candida tropicalis/efeitos dos fármacos , Candida tropicalis/isolamento & purificação , Caspofungina , Farmacorresistência Fúngica , Equinocandinas/química , Feminino , Humanos , Concentração de Íons de Hidrogênio , Lipopeptídeos/farmacologia , Micafungina , Testes de Sensibilidade MicrobianaRESUMO
Invasive fungal infections remain a major cause of morbidity and mortality in immunocompromised patients, and such infections are a substantial burden to healthcare systems around the world. However, the clinically available armamentarium for invasive fungal diseases is limited to 3 main classes (i.e., polyenes, triazoles, and echinocandins), and each has defined limitations related to spectrum of activity, development of resistance, and toxicity. Further, current antifungal therapies are hampered by limited clinical efficacy, high rates of toxicity, and significant variability in pharmacokinetic properties. New antifungal agents, new formulations, and novel combination regimens may improve the care of patients in the future by providing improved strategies to combat challenges associated with currently available antifungal agents. Likewise, therapeutic drug monitoring may be helpful, but its present use remains controversial due to the lack of available data. This article discusses new facets of antifungal therapy with a focus on new antifungal formulations and the synergistic effects between drugs used in combination therapy.