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1.
Mycoses ; 64(6): 656-667, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33609302

RESUMO

BACKGROUND: The effects of cryptococcemia on patient outcomes in those with or without HIV remain unclear. METHODS: One hundred and seventy-nine cryptococcemia patients were enrolled in this retrospective study. Demographic characteristics, blood test results and outcome were compared between the two groups. RESULTS: The diagnosis time of Cryptococcus infection was 2.0(0-6.0) days for HIV-infected patients, 5.0 (1.5-8.0) days for HIV-uninfected patients (p = .008), 2.0 (1.0-6.0) days for cryptococcal meningitis (CM) patients and 6.0 (5.0-8.0) days for non-CM patients (p < .001). HIV infection [adjusted odds ratio (AOR) (95% confidence interval): 6.0(2.3-15.9)], CRP < 15 mg/L [AOR:3.7(1.7-8.1)) and haemoglobin > 110 g/L [AOR:2.5(1.2-5.4)] were risk factors for CM development. Forty-six (25.7%) patients died within 90 days. ICU stay [AOR:2.8(1.1-7.1)], hypoalbuminemia [AOR:2.7(1.4-5.3)], no anti-cryptococcal treatment [AOR:4.7(1.9-11.7)] and altered consciousness [AOR:2.4(1.0-5.5)] were independent risk factors for 90-day mortality in all patients. HIV infection did not increase the 90-day mortality of cryptococcemia patients when anti-Cryptococcus treatment was available. Non-Amphotericin B treatment [AOR:3.4(1.0-11.2)] was associated with 90-day mortality in HIV-infected patients, but age ≥ 50.0 years old [AOR:2.7(1.0-2.9)], predisposing disease [AOR:4.1(1.2-14.2)] and altered consciousness [AOR:3.7(1.1-12.9)] were associated with 90-day mortality in HIV-uninfected patients who accepted anti-Cryptococcus treatment. CONCLUSION: HIV infection increased the incidence of CM rather than mortality in cryptococcemia patients. The predictive model was completely divergent in HIV-infected and HIV-uninfected patients, suggesting that novel strategies for diagnosis and treatment algorithms are urgently needed.


Assuntos
Criptococose , Infecções por HIV/complicações , Resultado do Tratamento , Adulto , Idoso , Antifúngicos/uso terapêutico , Criptococose/sangue , Criptococose/tratamento farmacológico , Criptococose/epidemiologia , Cryptococcus/efeitos dos fármacos , Cryptococcus/patogenicidade , Feminino , Humanos , Incidência , Masculino , Meningite Criptocócica/tratamento farmacológico , Meningite Criptocócica/epidemiologia , Pessoa de Meia-Idade , Mortalidade , Estudos Retrospectivos , Fatores de Risco
2.
Biomed Chromatogr ; 35(3): e5014, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33119961

RESUMO

RI76 is a novel 2-thiazolylhydrazone compound with reported antifungal activity. In preclinical drug development, it is fundamental to know the impurity profile and to understand degradation mechanisms of the molecule. In our study, RI76 was subjected to forced degradation conditions, and a stability-indicating HPLC-DAD method was developed and validated. Separation was carried out on a C18 column (150 × 4.6 mm i.d., 5 µm) maintained at 40°C using a 1 mL/min flow rate of 2 mM ammonium acetate with 0.1% formic acid (pH 3.0) and acetonitrile in gradient mode. The method was linear in the range of 0.7-91 µg/mL for RI76 and 0.7-25 µg/mL for its degradation product PD76. The formation of a major degradation product was quickly observed when RI76 was in aqueous solution. The chemical structure of this product, named PD76, was proposed based on LC-UV-MS experiments, synthesized in-house, and confirmed by NMR spectroscopy and chromatographic analysis. In vitro antifungal activity assays demonstrated that this resultant product shows a promising activity against clinically important Candida and Cryptococcus strains, matching or surpassing the activity of its precursor and of well-established antifungal drugs.


Assuntos
Antifúngicos/análise , Antifúngicos/farmacologia , Antifúngicos/química , Antifúngicos/farmacocinética , Candida/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão/métodos , Cryptococcus/efeitos dos fármacos , Estabilidade de Medicamentos , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos Testes
3.
Int J Mol Sci ; 22(8)2021 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-33920681

RESUMO

Punica granatum L. (pomegranate) fruit is known to be an important source of bioactive phenolic compounds belonging to hydrolysable tannins. Pomegranate extracts have shown antifungal activity, but the compounds responsible for this activity and their mechanism/s of action have not been completely elucidated up to now. The aim of the present study was the investigation of the inhibition ability of a selection of pomegranate phenolic compounds (i.e., punicalagin, punicalin, ellagic acid, gallic acid) on both plant and human fungal pathogens. In addition, the biological target of punicalagin was identified here for the first time. The antifungal activity of pomegranate phenolics was evaluated by means of Agar Disk Diffusion Assay and minimum inhibitory concentration (MIC) evaluation. A chemoinformatic analysis predicted for the first time topoisomerases I and II as potential biological targets of punicalagin, and this prediction was confirmed by in vitro inhibition assays. Concerning phytopathogens, all the tested compounds were effective, often similarly to the fungicide imazalil at the label dose. Particularly, punicalagin showed the lowest MIC for Alternaria alternata and Botrytis cinerea, whereas punicalin was the most active compound in terms of growth control extent. As for human pathogens, punicalagin was the most active compound among the tested ones against Candida albicans reference strains, as well as against the clinically isolates. UHPLC coupled with HRMS indicated that C. albicans, similarly to the phytopathogen Coniella granati, is able to hydrolyze both punicalagin and punicalin as a response to the fungal attack. Punicalagin showed a strong inhibitory activity, with IC50 values of 9.0 and 4.6 µM against C. albicans topoisomerases I and II, respectively. Altogether, the results provide evidence that punicalagin is a valuable candidate to be further exploited as an antifungal agent in particular against human fungal infections.


Assuntos
Antifúngicos/farmacologia , Taninos Hidrolisáveis/farmacologia , Punica granatum/química , Inibidores da Topoisomerase/farmacologia , Antifúngicos/química , Aspergillus/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Cryptococcus/efeitos dos fármacos , Taninos Hidrolisáveis/química , Inibidores da Topoisomerase/química
4.
Int J Mol Sci ; 22(18)2021 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-34576268

RESUMO

Fungal infections have become a major health concern, given that invasive infections by Candida, Cryptococcus, and Aspergillus species have led to millions of mortalities. Conventional antifungal drugs including polyenes, echinocandins, azoles, allylamins, and antimetabolites have been used for decades, but their limitations include off-target toxicity, drug-resistance, poor water solubility, low bioavailability, and weak tissue penetration, which cannot be ignored. These drawbacks have led to the emergence of novel antifungal therapies. In this review, we discuss the nanosystems that are currently utilized for drug delivery and the application of antifungal therapies.


Assuntos
Antifúngicos/farmacologia , Micoses/microbiologia , Nanomedicina , Aspergilose/tratamento farmacológico , Aspergillus/efeitos dos fármacos , Azóis/farmacologia , Candida/efeitos dos fármacos , Candidíase/tratamento farmacológico , Criptococose/tratamento farmacológico , Cryptococcus/efeitos dos fármacos , Sistemas de Liberação de Medicamentos , Desenho de Fármacos , Farmacorresistência Fúngica , Equinocandinas/farmacologia , Lipídeos/química , Nanopartículas Metálicas/química , Testes de Sensibilidade Microbiana , Polienos , Polímeros/química , Dióxido de Silício/química , Solubilidade
5.
FEMS Yeast Res ; 20(2)2020 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-32073632

RESUMO

Environmental stress often causes phenotypic changes among pathogenic cryptococci, such as altered antifungal susceptibility, changes in capsule and melanin formation, as well as altered levels of the membrane sterol and antifungal target, ergosterol. We therefore hypothesised that nitrogen limitation, a prevalent environmental stress in the natural habitat of these yeasts, might affect virulence and antifungal susceptibility. We tested the effect of different nitrogen concentrations on capsule, melanin and ergosterol biosynthesis, as well as amphotericin B (AmB) and fluconazole (FLU) susceptibility. This was achieved by culturing cryptococcal strains representing Cryptococcus neoformans and Cryptococcus gattii in media with high (0.53 g/l), control (0.42 g/l) and low (0.21 g/l) NH4Cl concentrations. India ink staining was used to determine capsule thickness microscopically, while melanin and ergosterol content were determined spectrophotometrically. We found that lower nitrogen concentrations enhanced both ergosterol and capsule biosynthesis, while a variable effect was observed on melanisation. Evaluation of drug tolerance using time-kill methodology, as well as tests for FLU heteroresistance, revealed that the low nitrogen cultures had the highest survival percentages in the presence of both AmB and FLU, and showed the highest frequency of FLU heteroresistance, suggesting that nitrogen concentration may indeed influence drug tolerance.


Assuntos
Anfotericina B/farmacologia , Antifúngicos/farmacologia , Cryptococcus/efeitos dos fármacos , Cryptococcus/metabolismo , Fluconazol/farmacologia , Nitrogênio/metabolismo , Cloreto de Amônio/análise , Cloreto de Amônio/farmacologia , Vias Biossintéticas/efeitos dos fármacos , Cryptococcus/classificação , Cryptococcus gattii/efeitos dos fármacos , Cryptococcus neoformans/efeitos dos fármacos , Meios de Cultura/química , Ergosterol/análise , Ergosterol/biossíntese , Melaninas/análise , Melaninas/biossíntese , Testes de Sensibilidade Microbiana , Nitrogênio/análise
6.
Med Mycol ; 58(4): 478-484, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31504739

RESUMO

Cryptococcemia is a life-threatening fungal infection. Sometimes, it is hard to diagnose. The studies to describe the characteristics of cryptococcemia specifically were limited. We performed this retrospective analysis in a Chinese hospital during 2002-2015, including 85 cryptococcemia cases and 52 Cryptococcus spp. isolates. The species, mating type, antifungal susceptibility and multilocus sequence typing of Cryptococcus spp. were determined. C. neoformans var. grubii MATα of sequence type (ST) 5 is the representative strain of cryptococcemia, accounting for 51 isolates. The MIC50/90 values were 0.5/0.5, 1.0/1.0, 2.0/4.0, ≤0.06/0.25, and ≤0.06/≤0.06 µg/ml for amphotericin B, flucytosine, fluconazole, itraconazole, and voriconazole, respectively. Cryptococcemia was the first diagnostic proof of cryptococcosis in 37 patients (43.5%, 37/85). Compared with the patients initially diagnosed of cryptococcosis in other sites (mainly cerebrospinal fluid), the patients firstly diagnosed by blood culture had prolonged time from admission to diagnosis of cryptococcosis (9 days vs. 2 days, P < .001) and higher 30-day mortality (54.1% vs. 20.8%, P = .003), while fewer symptoms of meningitis (45.9% vs. 100%, P < .001). For the patients receiving lumbar puncture, the occurrence of meningitis was similar between the patients firstly diagnosed by blood culture and those firstly diagnosed in other sites (94.1% vs. 100%, P = .26). However, the patients first diagnosed by blood culture had lower baseline intracranial pressure (250 mm H2O vs. 342.5 mm H2O, P = .001). In conclusion, patients with cryptococcemia as the first diagnostic proof of cryptococcosis usually had neglected subtle symptoms of meningitis, which may result in delayed diagnosis and catastrophic outcome.


Assuntos
Criptococose/microbiologia , Cryptococcus/classificação , Fungemia/microbiologia , Hospitais/estatística & dados numéricos , Adulto , Idoso , Antifúngicos/farmacologia , China , Criptococose/diagnóstico , Cryptococcus/efeitos dos fármacos , Cryptococcus/isolamento & purificação , Cryptococcus gattii/genética , Cryptococcus gattii/isolamento & purificação , Cryptococcus neoformans/genética , Cryptococcus neoformans/isolamento & purificação , DNA Fúngico/genética , Feminino , Fungemia/mortalidade , Genótipo , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Tipagem de Sequências Multilocus , Técnicas de Tipagem Micológica , Estudos Retrospectivos
7.
Med Mycol ; 58(6): 835-844, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31919505

RESUMO

Cryptococcosis is a life-threatening fungal infection, and its current treatment is toxic and subject to resistance. Drug repurposing represents an interesting approach to find drugs to reduce the toxicity of antifungals. In this study, we evaluated the combination of N-acetylcysteine (NAC) with amphotericin B (AMB) for the treatment of cryptococcosis. We examined the effects of NAC on fungal morphophysiology and on the macrophage fungicidal activity 3 and 24 hours post inoculation. The therapeutic effects of NAC combination with AMB were investigated in a murine model with daily treatments regimens. NAC alone reduced the oxidative burst generated by AMB in yeast cells, but did not inhibit fungal growth. The combination NAC + AMB decreased capsule size, zeta potential, superoxide dismutase activity and lipid peroxidation. In macrophage assays, NAC + AMB did not influence the phagocytosis, but induced fungal killing with different levels of oxidative bursts when compared to AMB alone: there was an increased reactive oxygen species (ROS) after 3 hours and reduced levels after 24 hours. By contrast, ROS remained elevated when AMB was tested alone, demonstrating that NAC reduced AMB oxidative effects without influencing its antifungal activity. Uninfected mice treated with NAC + AMB had lower concentrations of serum creatinine and glutamate-pyruvate transaminase in comparison to AMB. The combination of NAC + AMB was far better than AMB alone in increasing survival and reducing morbidity in murine-induced cryptococcosis, leading to reduced fungal burden in lungs and brain and also lower concentrations of pro-inflammatory cytokines in the lungs. In conclusion, NAC + AMB may represent an alternative adjuvant for the treatment of cryptococcosis.


Assuntos
Acetilcisteína/uso terapêutico , Anfotericina B/toxicidade , Antifúngicos/uso terapêutico , Criptococose/tratamento farmacológico , Ácido Desoxicólico/toxicidade , Rim/efeitos dos fármacos , Anfotericina B/farmacologia , Anfotericina B/uso terapêutico , Animais , Antifúngicos/farmacologia , Antifúngicos/toxicidade , Encéfalo/efeitos dos fármacos , Encéfalo/microbiologia , Creatinina/sangue , Criptococose/microbiologia , Cryptococcus/efeitos dos fármacos , Ácido Desoxicólico/farmacologia , Ácido Desoxicólico/uso terapêutico , Modelos Animais de Doenças , Combinação de Medicamentos , Reposicionamento de Medicamentos , Feminino , Rim/microbiologia , Pulmão/efeitos dos fármacos , Pulmão/microbiologia , Macrófagos/efeitos dos fármacos , Macrófagos/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Testes de Sensibilidade Microbiana , Espécies Reativas de Oxigênio
8.
Med Mycol ; 58(4): 493-504, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31297540

RESUMO

In this study, a Food and Drug Administration (FDA)-approved drug with previously unreported antifungal activity was investigated for suitability for use as an anticryptococcal agent. First, we screened a compound library of 1018 FDA-approved drugs against Cryptococcus neoformans. Of 52 drugs possessing anti-Cryptococcus activity, eltrombopag was chosen due to its novel activity. The susceptibility of Cryptococcus against eltrombopag was then studied by determining the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC), while the synergy of eltrombopag with other drugs was tested by fractional inhibitory concentration index (FICI). Eltrombopag had a limited spectrum of antifungal activity against C. neoformans/C. gattii species complex (MICs of 0.125 mg/l), Candida glabrata (MIC, 0.25 mg/l), and Trichophyton rubrum (MIC, 0.5 mg/l). Eltrombopag affected cryptococcal virulence factors, including capsule and biofilm formation, melanin production, and growth ability at 37°C. Further, RNA sequencing and deletion mutant library screening experiments revealed that genes involved in the calcineurin pathway, lipid biosynthesis, membrane component, and transporter genes were associated with eltrombopag. In addition, eltrombopag showed synergism with the calcineurin inhibitor FK506 (FICI < 0.5) against Cryptococcus species. In conclusion, eltrombopag exhibited excellent antifungal activity against Cryptococcus species potentially via a mode of action which interferes with virulence factors and the calcineurin pathway, indicating that eltrombopag might be usefully repurposed as an antifungal agent for treating cryptococcosis.


Assuntos
Antifúngicos/farmacologia , Benzoatos/farmacologia , Cryptococcus/efeitos dos fármacos , Reposicionamento de Medicamentos , Hidrazinas/farmacologia , Pirazóis/farmacologia , Arthrodermataceae/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Candida glabrata/efeitos dos fármacos , Cryptococcus/classificação , Cryptococcus/patogenicidade , Cryptococcus gattii/efeitos dos fármacos , Cryptococcus gattii/patogenicidade , Cryptococcus neoformans/efeitos dos fármacos , Cryptococcus neoformans/patogenicidade , Sinergismo Farmacológico , Redes e Vias Metabólicas , Testes de Sensibilidade Microbiana , Receptores de Trombopoetina/agonistas , Bibliotecas de Moléculas Pequenas , Tacrolimo/farmacologia
9.
Chem Biodivers ; 17(5): e1900550, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32149467

RESUMO

Two series of carbazole analogs of 8-methoxy-N-substituted-9H-carbazole-3-carboxamides (series 1) and carbazolyl substituted rhodanines (series 2) were synthesized through facile synthetic routes. All the final compounds from these two series were evaluated for their preliminary in vitro antifungal and antibacterial activity against four fungal (Candida albicans, Cryptococcus neoformans, Cryptococcus tropicalis and Aspergillus niger) and four bacterial (Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa) strains, respectively. Among the tested compounds, three compounds of series 1 displayed promising antifungal and antibacterial activity, especially against C. neoformans and S. aureus. In addition, one compound of series 1 displayed notable antimicrobial activity (MIC: 6.25 µg/mL) against clinical isolates of C. albicans and C. neoformans (MIC: 12.5 µg/mL). From the second series, four compounds exhibited significant antifungal and antibacterial activity, especially against C. neoformans and S. aureus. The most active compound of series 2 displayed a prominent antimicrobial activity against C. neoformans (MIC: 3.125 µg/mL) and S. aureus (MIC: 1.56 µg/mL), respectively.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Carbazóis/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Antifúngicos/síntese química , Antifúngicos/química , Aspergillus niger/efeitos dos fármacos , Bacillus subtilis/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Carbazóis/síntese química , Carbazóis/química , Cryptococcus/efeitos dos fármacos , Relação Dose-Resposta a Droga , Escherichia coli/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Relação Estrutura-Atividade
10.
Molecules ; 25(18)2020 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-32917001

RESUMO

Thymol (2-isopropyl-5-methylphenol) belongs to the phenolic monoterpenes and mostly occurs in thyme species. It is one of the main compounds of thyme essential oil. Both thymol and thyme essential oil have long been used in traditional medicine as expectorant, anti-inflammatory, antiviral, antibacterial, and antiseptic agents, mainly in the treatment of the upper respiratory system. The current search for new directions of biological or therapeutic activities of natural plant substances with known structures includes thyme essential oil and thymol. Novel studies have demonstrated their antibiofilm, antifungal, antileishmanial, antiviral, and anticancer properties. Also, their new therapeutic formulations, such as nanocapsules containing these constituents, can be beneficial in medicinal practice and create opportunities for their extensive use. Extensive application of thymol and thyme essential oil in the healthcare sector is very promising but requires further research and analysis.


Assuntos
Óleos Voláteis/química , Timol/química , Thymus (Planta)/química , Animais , Antibacterianos/farmacologia , Antifúngicos/farmacologia , Antiparasitários/farmacologia , Antivirais/farmacologia , Apoptose , Biofilmes/efeitos dos fármacos , Proliferação de Células , Cryptococcus/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana , Monoterpenos/química , Fenóis/química , Extratos Vegetais/farmacologia , Óleos de Plantas/química , Polímeros/química
11.
Clin Infect Dis ; 68(9): 1494-1501, 2019 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-30169607

RESUMO

BACKGROUND: The CryptoDex trial showed that dexamethasone caused poorer clinical outcomes and slowed fungal clearance in human immunodeficiency virus-associated cryptococcal meningitis. We analyzed cerebrospinal fluid (CSF) cytokine concentrations from participants over the first week of treatment to investigate mechanisms of harm and test 2 hypotheses: (1) dexamethasone reduced proinflammatory cytokine concentrations, leading to poorer outcomes and (2) leukotriene A4 hydrolase (LTA4H) genotype influenced the clinical impact of dexamethasone, as observed in tuberculous meningitis. METHODS: We included participants from Vietnam, Thailand, and Uganda. Using the Luminex system, we measured CSF concentrations of the following: interferon γ, tumor necrosis factor (TNF) α, granulocyte-macrophage colony-stimulating factor, monocyte chemoattractant 1, macrophage inflammatory protein 1α, and interleukin 6, 12p70, 8, 4, 10, and 17. We determined the LTA4H genotype based on the promoter region single-nucleotide polymorphism rs17525495. We assessed the impact of dexamethasone on cytokine concentration dynamics and the association between cytokine concentration dynamics and fungal clearance with mixed effect models. We measured the influence of LTA4H genotype on outcomes with Cox regression models. RESULTS: Dexamethasone increased the rate TNF-α concentration's decline in (-0.13 log2pg/mL/d (95% confidence interval, -.22 to -.06 log2pg/mL/d; P = .03), which was associated with slower fungal clearance (correlation, -0.62; 95% confidence interval, -.83 to -.26). LTA4H genotype had no statistically significant impact on outcome or response to dexamethasone therapy. Better clinical outcomes were associated with higher baseline concentrations of interferon γ. CONCLUSIONS: Dexamethasone may slow fungal clearance and worsen outcomes by increasing TNF-α concentration's rate of decline.


Assuntos
Dexametasona/efeitos adversos , Epóxido Hidrolases/genética , Expressão Gênica/efeitos dos fármacos , Glucocorticoides/efeitos adversos , Infecções por HIV/tratamento farmacológico , Meningite Criptocócica/tratamento farmacológico , Proteínas Adaptadoras de Transdução de Sinal/líquido cefalorraquidiano , Proteínas Adaptadoras de Transdução de Sinal/genética , Quimiocina CCL2/líquido cefalorraquidiano , Quimiocina CCL2/genética , Cryptococcus/efeitos dos fármacos , Cryptococcus/crescimento & desenvolvimento , Cryptococcus/patogenicidade , Epóxido Hidrolases/líquido cefalorraquidiano , Genótipo , Fator Estimulador de Colônias de Granulócitos e Macrófagos/líquido cefalorraquidiano , Fator Estimulador de Colônias de Granulócitos e Macrófagos/genética , HIV/crescimento & desenvolvimento , HIV/patogenicidade , Infecções por HIV/complicações , Infecções por HIV/imunologia , Infecções por HIV/mortalidade , Humanos , Interferon gama/líquido cefalorraquidiano , Interferon gama/genética , Interleucinas/líquido cefalorraquidiano , Interleucinas/genética , Meningite Criptocócica/complicações , Meningite Criptocócica/imunologia , Meningite Criptocócica/mortalidade , Análise de Sobrevida , Tailândia , Resultado do Tratamento , Fator de Necrose Tumoral alfa/líquido cefalorraquidiano , Fator de Necrose Tumoral alfa/genética , Uganda , Vietnã
12.
Med Mycol ; 57(3): 374-383, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-29878229

RESUMO

We found that a large inoculum of Cryptococcus gattii cells, when plated on Dulbecco's modified eagle's medium (DMEM) incorporated into agar, died within a few hours provided that DMEM agar plates had been stored in darkness for approximately 3 days after preparation. Standard conditions were developed for quantification of killing. The medium lost its fungicidal activity when exposed to visible light of wave length ∼400 nm. The amount of energy required was estimated at 5.8 × 104 joules @ 550 nm. Liquid DMEM conditioned by incubation over DMEM agar plates stored in darkness was fungicidal. We found that fungicidal activity was heat-stable (100°C). Dialysis tubing with MWC0 < 100 Daltons retained fungicidal activity. Neutral pH was required. Strains of Cryptococcus were uniformly sensitive, but some Candida species were resistant. Components of DMEM required for killing were pyridoxal and cystine. Micromolar amounts of iron shortened the time required for DMEM agar plates to become fungicidal when stored in the dark. Organic and inorganic compounds bearing reduced sulfur atoms at millimolar concentrations inhibited fungicidal activity. Our results point to a light-sensitive antifungal compound formed by reaction of pyridoxal with cystine possibly by Schiff base formation.


Assuntos
Antifúngicos/farmacologia , Cryptococcus/efeitos dos fármacos , Cryptococcus/efeitos da radiação , Meios de Cultura/química , Luz , Ágar/química , Cryptococcus/crescimento & desenvolvimento , Cistina/farmacologia , Concentração de Íons de Hidrogênio , Piridoxal/farmacologia , Bases de Schiff/química
13.
Med Mycol ; 57(1): 84-91, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-29471408

RESUMO

Cryptococcosis is an opportunistic or primary fungal infection considered to be the most prevalent fatal fungal disease worldwide. Owing to the limited number of available drugs, it is necessary to search for novel antifungal compounds. In the present work, we assessed the antifungal efficacy of three thiazole derivatives (1, 2, and 3). We conducted in vitro and in vivo assays to investigate their effects on important virulence factors, such as capsule and biofilm formation. In addition, the phagocytosis index of murine macrophages exposed to compounds 1, 2, and 3 and the in vivo efficacy of 1, 2, and 3 in Galleria mellonella infected with Cryptococcus spp. were evaluated. All compounds exhibited antifungal activity against biofilms and demonstrated a reduction in biofilm metabolic activity by 43-50% for C. gattii and 26-42% for C. neoformans. Thiazole compounds promoted significant changes in the capsule thickness of C. gattii compared to that of C. neoformans. Further examination of these compounds suggests that they can improve the phagocytosis process of peritoneal murine macrophages in vitro, causing an increase in the phagocytosis rate. Survival percentage was examined in the invertebrate model Galleria mellonella larvae, and only compound 3 could increase the survival at doses of 5 mg/kg after infection with C. gattii (P = .0001) and C. neoformans (P = .0007), similar to fluconazole at 10 mg/kg. The results demonstrated that thiazole compounds, mainly compound 3, have potential to be used for future studies in the search for new therapeutics for cryptococcosis.


Assuntos
Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Criptococose/microbiologia , Cryptococcus/efeitos dos fármacos , Cryptococcus/patogenicidade , Tiazóis/farmacologia , Fatores de Virulência/antagonistas & inibidores , Animais , Antifúngicos/química , Biofilmes/crescimento & desenvolvimento , Células Cultivadas , Criptococose/imunologia , Modelos Animais de Doenças , Polissacarídeos Fúngicos/biossíntese , Larva/microbiologia , Larva/fisiologia , Macrófagos/efeitos dos fármacos , Macrófagos/microbiologia , Camundongos , Estrutura Molecular , Mariposas , Fagocitose/efeitos dos fármacos , Análise de Sobrevida , Tiazóis/química
14.
Bioorg Med Chem Lett ; 29(5): 729-733, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30655213

RESUMO

Fungal infections caused by Candida and Cryptococcus are particularly dangerous for immunocompromised individuals. In this study, we identified that benzimidazole fused pyrrolo[3,4-b]quinoline compounds have potent antifungal activity against several clinical isolates of pathogenic fungal strains. Specifically, the compound 6a did not show cytotoxicity against mammalian cells at a concentration that inhibits the growth of fungal strains. In addition, the compound 6a also significantly reduced the metabolic activity of fungal cells in the Candida albicans biofilms. Collectively, our results indicate that benzimidazole fused quinoline compounds have a potential to develop as an antifungal agents.


Assuntos
Antifúngicos/farmacologia , Benzimidazóis/química , Candida albicans/efeitos dos fármacos , Cryptococcus/efeitos dos fármacos , Pirróis/química , Quinolinas/química , Biofilmes/efeitos dos fármacos , Testes de Sensibilidade Microbiana
15.
Bioorg Med Chem Lett ; 29(23): 126713, 2019 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-31668974

RESUMO

Fosmanogepix (APX001) is a first-in-class prodrug molecule that is currently in Phase 2 clinical trials for invasive fungal infections. The active moiety manogepix (APX001A) inhibits the novel fungal protein Gwt1. Gwt1 catalyzes an early step in the GPI anchor biosynthesis pathway. Here we describe the synthesis and evaluation of 292 new and 24 previously described analogs that were synthesized using a series of advanced intermediates to allow for rapid analoging. Several compounds demonstrated significantly (8- to 32-fold) improved antifungal activity against both Cryptococcus neoformans and C. gattii as compared to manogepix. Further in vitro characterization identified three analogs with a similar preliminary safety and in vitro profile to manogepix and superior activity against Cryptococcus spp.


Assuntos
Aminopiridinas/farmacologia , Antifúngicos/farmacologia , Cryptococcus/efeitos dos fármacos , Isoxazóis/farmacologia , Proteínas de Saccharomyces cerevisiae/antagonistas & inibidores , Aminopiridinas/síntese química , Aminopiridinas/química , Antifúngicos/síntese química , Antifúngicos/química , Relação Dose-Resposta a Droga , Proteínas Fúngicas , Isoxazóis/síntese química , Isoxazóis/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Proteínas de Saccharomyces cerevisiae/metabolismo , Relação Estrutura-Atividade
16.
Bioorg Med Chem Lett ; 29(16): 2059-2063, 2019 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-31320146

RESUMO

Invasive fungal infections are one of the leading causes of nosocomial bloodstream infections with a limited treatment option. A series of derivatized spirooxindolo-pyrrolidine tethered indole and imidazole heterocyclic hybrids have been synthesized, and their antifungal activity against fungal strains were determined. Here we characterize the antifungal activity of a specific spirooxindolo-pyrrolidine hybrid, dubbed compound 9c, a spirooxindolo-pyrrolidine tethered imidazole synthesized with a 2-chloro and trifluoromethoxy substituent. The compound 9c exhibited no cytotoxicity against mammalian cell line at concentrations that inhibited fungal strains. Compound 9c also significantly inhibited the fungal hyphae and biofilm formation. Our results indicate that spirooxindolo-pyrrolidine heterocyclic hybrids potentially represent a broad class of chemical agents with promising antifungal potential.


Assuntos
Antifúngicos/farmacologia , Imidazóis/farmacologia , Indóis/farmacologia , Pirrolidinas/farmacologia , Compostos de Espiro/farmacologia , Antifúngicos/síntese química , Antifúngicos/toxicidade , Biofilmes/efeitos dos fármacos , Candida/efeitos dos fármacos , Candida/fisiologia , Linhagem Celular Tumoral , Cryptococcus/efeitos dos fármacos , Cryptococcus/fisiologia , Humanos , Imidazóis/síntese química , Imidazóis/toxicidade , Indóis/síntese química , Indóis/toxicidade , Testes de Sensibilidade Microbiana , Pirrolidinas/síntese química , Pirrolidinas/toxicidade , Compostos de Espiro/síntese química , Compostos de Espiro/toxicidade
17.
J Nat Prod ; 82(3): 566-572, 2019 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-30817148

RESUMO

Lippia species share various pharmacological activities and are used in traditional cooking and medicine worldwide. Combined chromatographic techniques such as column chromatography, high-performance liquid chromatography, and countercurrent chromatography led to the purification of two new antifungal phenylpropanoid glycosides, lippiarubelloside A (1) and lippiarubelloside B (2), by bioactivity-directed fractionation of an ethanol-soluble extract from Lippia rubella, in addition to the known active related compounds forsythoside A (3), verbascoside (4), isoverbascoside (5), and poliumoside (6). The structures of compounds 1 and 2 were determined by comparison of their NMR spectroscopic data with the prototype active compound 4. Cryptococcus neoformans, which causes opportunistic lung infections, was sensitive to compounds 1-6 in the concentration range of 15-125 µg/mL. A synergistic effect (FICindex = 0.5) between 3 and amphotericin B was demonstrated. The glycosylated flavonoids pectolinarin (7), linarin (8), and siparunoside (9) were also isolated.


Assuntos
Antifúngicos/farmacologia , Glicosídeos/farmacologia , Lippia/química , Fenilpropionatos/farmacologia , Antifúngicos/química , Candida/efeitos dos fármacos , Cryptococcus/efeitos dos fármacos , Glicosídeos/química , Fenilpropionatos/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Análise Espectral/métodos
18.
Mycoses ; 62(6): 508-512, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30776159

RESUMO

Cryptococcus species are an encapsulated fungal pathogen that cause cryptococcal meningitis. There are limited therapeutic options for this infection. The management includes the use of different antifungals such as amphotericin B, flucytosine, or fluconazole, either alone or in combination. However, numerous therapeutic failures, as well as the limited effectiveness of such therapeutics, have been described. Diphenyl diselenide is a chemically synthesised molecule with was found to have antimicrobial activity. In this study, we evaluated the antifungal activities of fluconazole, amphotericin B and flucytosine, in combination with diphenyl diselenide against 30 clinical isolates of Cryptococcus spp. using CLSI M27-A3 method and the checkerboard microdilution technique. Our results show that the combination of flucytosine and diphenyl diselenide displayed 100% of synergism. However, when we analysed (PhSe)2 plus AMB or FLZ we observed around 70% of indifference. Our results suggest that the combination of diphenyl diselenide with other antifungal agents deserves attention as a new option for the development of alternative therapies for cryptococcosis.


Assuntos
Anfotericina B/farmacologia , Antifúngicos/farmacologia , Derivados de Benzeno/farmacologia , Cryptococcus/efeitos dos fármacos , Sinergismo Farmacológico , Fluconazol/farmacologia , Flucitosina/farmacologia , Compostos Organosselênicos/farmacologia , Criptococose/microbiologia , Humanos , Testes de Sensibilidade Microbiana
19.
Mycoses ; 62(5): 441-449, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30184276

RESUMO

BACKGROUND: Cryptococcus isolates with high MICs to fluconazole are increasingly reported, and a potential clinical impact has been advocated. However, there are different methods to evaluate fluconazole MICs and comparative analysis among such techniques and their comprehensive correlation with clinical outcome are not available. METHODS: Over a 13-year period (2000-2013), fluconazole MICs were determined for 62 cryptococcal isolates recovered from 22 patients with cryptococcosis using CLSI M27-A3, EUCAST, E test and Sensititre YeastOne, simultaneously. The relationship between the fluconazole MICs and the clinical outcome at week 10 was assessed in patients who received fluconazole as induction or maintenance therapy (n = 16). RESULTS: The percentage of cryptococcal strains with MIC values ≥16 µg/mL according to different methods was CLSI 1.6%, EUCAST 16.1%, E test 31.6% and Sensititre YeastOne 53.2%. Among the 16 patients treated with fluconazole, no correlation between clinical outcome and any MIC value obtained with either method was observed. The only variable independently associated with a poor outcome was having a disseminated disease. CONCLUSIONS: There is a weak correlation between fluconazole MICs against Cryptococcus spp. as determined by CLSI, EUCAST, E test and Sensititre YeastOne. Neither procedure could predict the clinical outcome of patients with cryptococcosis receiving fluconazole-based therapy. With present methods, fluconazole resistance in Cryptococcus may be clinically misleading.


Assuntos
Antifúngicos/farmacologia , Criptococose/tratamento farmacológico , Cryptococcus/efeitos dos fármacos , Farmacorresistência Fúngica , Fluconazol/farmacologia , Adulto , Idoso , Criptococose/microbiologia , Cryptococcus/isolamento & purificação , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Resultado do Tratamento
20.
Mycoses ; 62(8): 686-691, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31120606

RESUMO

Cryptococcal meningitis (CM) carries a high risk of mortality with increasing incidences in immune competent hosts. Current treatments are not well tolerated, and evaluation of other treatments is needed. Fluconazole and 5-flucytosine in treating immune competent hosts have not been characterised. To evaluate the efficacy of fluconazole and 5-flucytosine in treating non-HIV- and non-transplant-associated CM. We performed a retrospective cohort study of the outcomes in immune competent patients with CM treated with fluconazole and 5-flucytosine or deoxycholate-amphotericin B and 5-flucytosine. The primary outcome was treatment response evaluated at the 12th week after initiation of antifungal therapy. A total of 43 and 47 patients received amphotericin B deoxycholate and 5-flucytosine or fluconazole and 5-flucytosine, respectively. A total of 38 (88.4%) patients cannot tolerate recommended doses of amphotericin B deoxycholate and 5-flucytosine (patients needed dose reduction during the treatment). Patients given fluconazole and 5-flucytosine had higher baseline cryptococcal burdens (median 3632 versus 900 cryptococci/mL, P = 0.008). No significant differences were seen in cryptococcus clearance (74.4% vs 70.2%, P = 0.814), treatment time (39 days, 20-69 days vs 21 days, 7-63 days, P = 0.107) and successful response (including complete and partial responses) rates (69.7% vs 72.3%, P = 0.820). Fluconazole and 5-flucytosine treatment had lower total adverse events (19.1% vs 90.7%, P < 0.001). Fluconazole and 5-flucytosine had relatively high efficacy with few adverse events in treating CM. Fluconazole and 5-flucytosine therapy is promising in patients that do not tolerate or are not suited for amphotericin B deoxycholate treatment.


Assuntos
Antifúngicos/uso terapêutico , Fluconazol/uso terapêutico , Flucitosina/uso terapêutico , Meningite Criptocócica/tratamento farmacológico , Adulto , Anfotericina B/uso terapêutico , Cryptococcus/efeitos dos fármacos , Ácido Desoxicólico/uso terapêutico , Combinação de Medicamentos , Quimioterapia Combinada , Feminino , Infecções por HIV , Humanos , Imunocompetência , Masculino , Meningite Criptocócica/microbiologia , Pessoa de Meia-Idade , Transplante de Órgãos , Estudos Retrospectivos , Resultado do Tratamento
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