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1.
Med Chem ; 16(1): 128-139, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-30501601

RESUMO

BACKGROUND: It is assumed that the unfavorable selective toxicity of an antifungal drug Amphotericin B (AmB) can be improved upon chemical modification of the antibiotic molecule. OBJECTIVE: The aim of this study was verification of the hypothesis that introduction of bulky substituents at the amino sugar moiety of the antibiotic may result in diminishment of mammalian in vitro toxicity of thus prepared AmB derivatives. METHODS: Twenty-eight derivatives of AmB were obtained upon chemical modification of the amino group of mycosamine residue. This set comprised 10 N-succinimidyl-, 4 N-benzyl-, 5 Nthioureidyl- and 9 N-aminoacyl derivatives. Parameters characterizing biological in vitro activity of novel compounds were determined. RESULTS: All the novel compounds demonstrated lower than AmB antifungal in vitro activity but most of them exhibited negligible cytotoxicity against human erythrocytes and three mammalian cell lines. In consequence, the selective toxicity of majority of novel antifungals, reflected by the selective toxicity index (STI = EH50/IC50) was improved in comparison with that of AmB, especially in the case of 5 compounds. The novel AmB derivatives with the highest STI, induced substantial potassium efflux from Candida albicans cells at concentrations slightly lower than IC50s but did not trigger potassium release from human erythrocytes at concentrations lower than 100 µg/mL. CONCLUSION: Some of the novel AmB derivatives can be considered promising antifungal drug candidates.


Assuntos
Anfotericina B/farmacologia , Antifúngicos/farmacologia , Hexosaminas/farmacologia , Anfotericina B/síntese química , Anfotericina B/química , Antifúngicos/síntese química , Antifúngicos/química , Aspergillus/efeitos dos fármacos , Candida/efeitos dos fármacos , Cryptococcus/efeitos dos fármacos , Relação Dose-Resposta a Droga , Fusarium/efeitos dos fármacos , Hexosaminas/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Mucor/efeitos dos fármacos , Rhizopus/efeitos dos fármacos , Relação Estrutura-Atividade
2.
J Appl Microbiol ; 128(1): 88-101, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31509623

RESUMO

AIMS: Staphylococcus aureus (a bacterial pathogen) and Candida sp. (opportunistic fungi) are two clinically relevant biofilm-forming microbes responsible for a majority of community- and nosocomial-acquired infections. Dual species biofilm formation between S. aureus and Candida sp. extremely enhances the antimicrobial resistance of the micro-organisms and is difficult to treat with antibiotic therapy. Hence, it is crucial to explore new antimicrobial agents. Auranofin (AF) is a mixed ligand gold compound and has recently been repurposed as an antibacterial and antifungal agent. However, the effects of AF against dual species biofilm have remained largely untested. METHODS AND RESULTS: In the present study, by constructing biofilms on microplates and urinary catheter surfaces, AF showed strong planktonic cells and biofilm inhibitory effects against mono- and dual culture models of S. aureus and Candida albicans but only exhibited moderate antibiofilm effects on Candida parapsilosis. Auranofin could be synergistic with subminimal inhibitory concentrations of amphotericin B against S. aureus + C. albicans/C. parapsilosis dual biofilms. Auranofin also showed effective antimicrobial effects on vancomycin-resistant strains. However, the antimicrobial effects of AF were decreased in the presence of heat-inactivated foetal bovine serum. CONCLUSIONS: In summary, AF could effectively inhibit S. aureus and C. albicans mono- and dual biofilm formation in vitro. SIGNIFICANCE AND IMPACT OF THE STUDY: Coexistence between Staphylococcus aureus and Candida sp. in dual biofilms leads to increased resistance to some conventionally used antimicrobials, indicating a need for alternative treatments. This study demonstrates the potential for the Au-containing compound AF in the treatment of dual biofilm infections and encourages further investigation of this treatment for clinical use.


Assuntos
Anti-Infecciosos/farmacologia , Auranofina/farmacologia , Biofilmes/efeitos dos fármacos , Candida/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Anfotericina B/farmacologia , Biofilmes/crescimento & desenvolvimento , Candida/crescimento & desenvolvimento , Técnicas de Cocultura , Sinergismo Farmacológico , Testes de Sensibilidade Microbiana , Especificidade da Espécie , Staphylococcus aureus/crescimento & desenvolvimento , Cateteres Urinários/microbiologia
3.
Int J Nanomedicine ; 14: 7593-7607, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31802863

RESUMO

Background: Amphotericin B (Amp) and Betulinic acid (BA) as antileishmanial agents have negligible water solubility and high toxicity. To solve these problems, for the first time, chitosan nanoparticles and Anionic Linear Globular Dendrimer (D) were synthesized for the treatment of Leishmania major (L. major). Method: Chitosan and dendrimer nanoparticles were synthesized, and Amp and BA were loaded into the nanoparticles. The particles were then characterized using various methods and their efficacy was evaluated in vitro and in vivo environments (parasite burden was confirmed using pathological studies and real-time PCR methods). Result: The results of docking showed that Amp and BA can be loaded into chitosan and dendrimer nanoparticles. The results of physically drug loading efficiency for AK (Amphotericin B-chitosan), BK (Betulinic acid-chitosan), AD (Amphotericin B-Dendrimer) and BD (Betulinic acid- Dendrimer) were 90, 93, 84 and 96 percent, respectively. The characterization results indicated that the drugs were loaded into nanoparticles physically. Moreover, the increased solubility rate for AD=478, BD=790, AK=80 and BK=300 folds. Furthermore, the results of the drug delivery system showed the slow controlled drug release pattern with cellular uptake of more than 90%. The treatment results showed a 100 percent decrease of toxicity for the all nanodrugs was observed in vivo and in vitro environments. Moreover, AK10 and BK20 mg/kg reduced parasite burden by 83 percent (P<0.001), while AD50 and BD40 mg/kg reduced it to a lesser extent compared to glucantime. Conclusion: All the synthesized nanodrugs were completely succeeded by 100% to recovery the L. major induced pathological effects in the infected footpad. Also, the results of present study were confirmed with real-time PCR and the results showed that AK and BK were succeeded in a large extent to the treatment of L. major infection (P<0.001), therefore AK and BK could be considered as proper alternatives of choices drugs.


Assuntos
Anfotericina B/farmacologia , Quitosana/química , Dendrímeros/química , Leishmania major/efeitos dos fármacos , Leishmania major/genética , Nanopartículas/química , Reação em Cadeia da Polimerase em Tempo Real/métodos , Triterpenos/química , Anfotericina B/química , Animais , Antiprotozoários/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Simulação de Acoplamento Molecular , Nanopartículas/uso terapêutico , Nanopartículas/toxicidade , Parasitos/efeitos dos fármacos , Parasitos/genética , Solubilidade , Termodinâmica
4.
Pol J Microbiol ; 68(3): 303-308, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31880875

RESUMO

The data on susceptibility to antifungals of new species within Candida glabrata complex are limited. Our study was to enrich a global knowledge of yeast epidemiology and drug resistance. The study was focused on the identification of species within clinical isolates of the C. glabrata complex and on the determination of their resistance to antifungals. Four hundred forty-five clinical C. glabrata sensu lato strains were isolated from different clinical samples at routine mycological exams at the Infant Jesus Teaching Hospital in Warsaw. The identification of the most of tested isolates to species complex level was performed using the ID 32 C system. The identification of C. nivariensis and C. bracarensis species within the C. glabrata complex was performed by DNA sequencing. The MICs of amphotericin B, fluconazole, itraconazole, posaconazole, voriconazole, caspofungin, anidulafungin, and micafungin were determined by E-test. Twenty-four isolates did not have an ITS-1 region, characteristic of C. glabrata sensu stricto and their D1/D2 regions of the 26S rRNA were 99% homologous to C. nivariensis 26S rRNA. No strains of C. bracarensis were recovered. C. nivariensis strains were very susceptible to amphotericin B, anidulafungin, micafungin, and caspofungin. Ninety-two percent of C. nivariensis were resistant to itraconazole. The halves of the strains was resistant to posaconazole. Eighty-three percent of C. nivariensis were susceptible to voriconazole. None of the tested strains were susceptible to fluconazole. In the present study, none of the C. nivariensis strains were simultaneously resistant to azoles and echinocandins. C. nivariensis should be recognized as an emerging pathogen, resistant to azoles.The data on susceptibility to antifungals of new species within Candida glabrata complex are limited. Our study was to enrich a global knowledge of yeast epidemiology and drug resistance. The study was focused on the identification of species within clinical isolates of the C. glabrata complex and on the determination of their resistance to antifungals. Four hundred forty-five clinical C. glabrata sensu lato strains were isolated from different clinical samples at routine mycological exams at the Infant Jesus Teaching Hospital in Warsaw. The identification of the most of tested isolates to species complex level was performed using the ID 32 C system. The identification of C. nivariensis and C. bracarensis species within the C. glabrata complex was performed by DNA sequencing. The MICs of amphotericin B, fluconazole, itraconazole, posaconazole, voriconazole, caspofungin, anidulafungin, and micafungin were determined by E-test. Twenty-four isolates did not have an ITS-1 region, characteristic of C. glabrata sensu stricto and their D1/D2 regions of the 26S rRNA were 99% homologous to C. nivariensis 26S rRNA. No strains of C. bracarensis were recovered. C. nivariensis strains were very susceptible to amphotericin B, anidulafungin, micafungin, and caspofungin. Ninety-two percent of C. nivariensis were resistant to itraconazole. The halves of the strains was resistant to posaconazole. Eighty-three percent of C. nivariensis were susceptible to voriconazole. None of the tested strains were susceptible to fluconazole. In the present study, none of the C. nivariensis strains were simultaneously resistant to azoles and echinocandins. C. nivariensis should be recognized as an emerging pathogen, resistant to azoles.


Assuntos
Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Candidíase/microbiologia , Anfotericina B/farmacologia , Candida/classificação , Candida/genética , Candida/isolamento & purificação , Candidíase/epidemiologia , Farmacorresistência Fúngica , Fluconazol/farmacologia , Hospitais de Ensino/estatística & dados numéricos , Humanos , Testes de Sensibilidade Microbiana , Polônia/epidemiologia , Prevalência , Triazóis/farmacologia
5.
Vet Parasitol ; 276: 108976, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31739256

RESUMO

Cutaneous leishmaniosis (CL) is a parasitic disease in animals and human with no satisfactory treatments and vaccination. Rapamycin is a potent inhibitor of mammalian target of rapamycin (mTOR) with various applications. Here, the effect of rapamycin alone or in combination with two other drugs, namely amphotericin B (AmB) and glucantime, was investigated against Leishmania tropica infection. In vitro viability and electron microscopy evaluation of the parasites showed detrimental changes in their appearance and viability. Treatment with clinically relevant dose of rapamycin (10.2 µg/dose) is able to control the parasite load in BALB/c mice infected with L. tropica. Furthermore, the cytokine profiles showed significant polarization towards Th1 immune response. Surprisingly, combination therapy with either AmB or glucantime was not efficient. Rapamycin is showed an effective alternative therapy against leishmaniosis caused by L. tropica.


Assuntos
Antiprotozoários/uso terapêutico , Leishmania tropica/efeitos dos fármacos , Leishmaniose Cutânea/tratamento farmacológico , Sirolimo/uso terapêutico , Anfotericina B/farmacologia , Anfotericina B/uso terapêutico , Animais , Antiprotozoários/farmacologia , Linhagem Celular Tumoral , Citocinas/análise , Feminino , Humanos , Concentração Inibidora 50 , Leishmania tropica/crescimento & desenvolvimento , Leishmania tropica/ultraestrutura , Leishmaniose Cutânea/prevenção & controle , Linfonodos/parasitologia , Antimoniato de Meglumina/farmacologia , Antimoniato de Meglumina/uso terapêutico , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Carga Parasitária , Distribuição Aleatória , Sirolimo/farmacologia , Serina-Treonina Quinases TOR/efeitos dos fármacos
6.
Int J Nanomedicine ; 14: 6073-6101, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31686803

RESUMO

Background: Amphotericin B (AmB) as a liposomal formulation of AmBisome is the first line of treatment for the disease, visceral leishmaniasis, caused by the parasite Leishmania donovani. However, nephrotoxicity is very common due to poor water solubility and aggregation of AmB. This study aimed to develop a water-soluble covalent conjugate of gold nanoparticle (GNP) with AmB for improved antileishmanial efficacy and reduced cytotoxicity. Methods: Citrate-reduced GNPs (~39 nm) were functionalized with lipoic acid (LA), and the product GNP-LA (GL ~46 nm) was covalently conjugated with AmB using carboxyl-to-amine coupling chemistry to produce GNP-LA-AmB (GL-AmB ~48 nm). The nanoparticles were characterized by dynamic light scattering, transmission electron microscopy (TEM), and spectroscopic (ultraviolet-visible and infrared) methods. Experiments on AmB uptake of macrophages, ergosterol depletion of drug-treated parasites, cytokine ELISA, fluorescence anisotropy, flow cytometry, and gene expression studies established efficacy of GL-AmB over standard AmB. Results: Infrared spectroscopy confirmed the presence of a covalent amide bond in the conjugate. TEM images showed uniform size with smooth surfaces of GL-AmB nanoparticles. Efficiency of AmB conjugation was ~78%. Incubation in serum for 72 h showed <7% AmB release, indicating high stability of conjugate GL-AmB. GL-AmB with AmB equivalents showed ~5-fold enhanced antileishmanial activity compared with AmB against parasite-infected macrophages ex vivo. Macrophages treated with GL-AmB showed increased immunostimulatory Th1 (IL-12 and interferon-γ) response compared with standard AmB. In parallel, AmB uptake was ~5.5 and ~3.7-fold higher for GL-AmB-treated (P<0.001) macrophages within 1 and 2 h of treatment, respectively. The ergosterol content in GL-AmB-treated parasites was ~2-fold reduced compared with AmB-treated parasites. Moreover, GL-AmB was significantly less cytotoxic and hemolytic than AmB (P<0.01). Conclusion: GNP-based delivery of AmB can be a better, cheaper, and safer alternative than available AmB formulations.


Assuntos
Anfotericina B/síntese química , Antiprotozoários/farmacologia , Ouro/química , Nanopartículas Metálicas/química , Anfotericina B/química , Anfotericina B/farmacologia , Animais , Antiprotozoários/química , Candida albicans/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Linhagem Celular , Citocinas/metabolismo , Difusão Dinâmica da Luz , Ergosterol/metabolismo , Hemólise/efeitos dos fármacos , Humanos , Leishmania donovani/efeitos dos fármacos , Leishmania donovani/crescimento & desenvolvimento , Estágios do Ciclo de Vida/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Nanopartículas Metálicas/ultraestrutura , Camundongos , Carbonilação Proteica/efeitos dos fármacos , Compostos de Sulfidrila/metabolismo , Ácido Tióctico/química , Resultado do Tratamento
7.
Molecules ; 24(18)2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-31505853

RESUMO

Complement (C) activation can underlie the infusion reactions to liposomes and other nanoparticle-based medicines, a hypersensitivity syndrome that can be partially reproduced in animal models. However, the sensitivities and manifestations substantially differ in different species, and C activation may not be the only cause of pathophysiological changes. In order to map the species variation of C-dependent and -independent pseudoallergy (CARPA/CIPA), here we used known C activators and C activator liposomes to compare their acute hemodynamic, hematological, and biochemical effects in rats. These C activators were cobra venom factor (CVF), zymosan, AmBisome (at 2 doses), its amphotericin B-free vehicle (AmBisombo), and a PEGylated cholesterol-containing liposome (PEG-2000-chol), all having different powers to activate C in rat blood. The pathophysiological endpoints measured were blood pressure, leukocyte and platelet counts, and plasma thromboxane B2, while C activation was assessed by C3 consumption using the Pan-Specific C3 assay. The results showed strong linear correlation between C activation and systemic hypotension, pointing to a causal role of C activation in the hemodynamic changes. The observed thrombocytopenia and leukopenia followed by leukocytosis also correlated with C3 conversion in case of C activators, but not necessarily with C activation by liposomes. These findings are consistent with the double hit hypothesis of hypersensitivity reactions (HSRs), inasmuch as strong C activation can fully account for all symptoms of HSRs, but in case of no-, or weak C activators, the pathophysiological response, if any, is likely to involve other activation pathways.


Assuntos
Ativação do Complemento/efeitos dos fármacos , Síndrome de Hipersensibilidade a Medicamentos/tratamento farmacológico , Leucocitose/sangue , Lipossomos/farmacologia , Anfotericina B/química , Anfotericina B/farmacologia , Animais , Colesterol/química , Convertases de Complemento C3-C5/química , Convertases de Complemento C3-C5/farmacologia , Proteínas do Sistema Complemento/química , Proteínas do Sistema Complemento/metabolismo , Síndrome de Hipersensibilidade a Medicamentos/etiologia , Síndrome de Hipersensibilidade a Medicamentos/patologia , Venenos Elapídicos/química , Venenos Elapídicos/farmacologia , Humanos , Hipotensão/sangue , Hipotensão/induzido quimicamente , Leucocitose/induzido quimicamente , Leucopenia/sangue , Leucopenia/induzido quimicamente , Lipossomos/química , Nanopartículas/química , Polietilenoglicóis/química , Ratos , Trombocitopenia/sangue , Trombocitopenia/induzido quimicamente , Zimosan/química , Zimosan/farmacologia
8.
Eur J Med Chem ; 183: 111660, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31514064

RESUMO

This mini-review focuses on leishmanicidal drugs that were sourced from small molecules previously approved for other diseases. The mechanisms of action of these molecules are herein explored, to probe the origins of their inter-species growth inhibitory activities. It is shown how the transversal action of the azoles - fluconazole, posaconazole and itraconazole - in both fungi and Leishmania is due to the occurrence of the same target, lanosterol 14-α-demethylase, in these two groups of species. In turn, the drugs miltefosine and amphotericin B are presented as truly multi-target agents, acting on small molecules, proteins, genes and even organelles. Steps towards future leishmanicidal drug candidates based on the multi-target strategy and on drug repurposing are also briefly presented.


Assuntos
Antifúngicos , Itraconazol , Leishmaniose/tratamento farmacológico , Anfotericina B/farmacologia , Antifúngicos/química , Antifúngicos/farmacologia , Reposicionamento de Medicamentos , Farmacorresistência Fúngica/efeitos dos fármacos , Fluconazol/farmacologia , Humanos , Itraconazol/química , Itraconazol/farmacologia , Leishmaniose/enzimologia , Terapia de Alvo Molecular , Fosforilcolina/análogos & derivados , Fosforilcolina/farmacologia , Esterol 14-Desmetilase/metabolismo , Triazóis/farmacologia , Voriconazol/farmacologia
9.
J Med Microbiol ; 68(11): 1664-1670, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31553302

RESUMO

Purpose. To assess in vitro activities of nine antifungal agents (amphotericin B, fluconazole, voriconazole, itraconazole, posaconazole, caspofungin, micafungin, terbinafine and 5-flucytosine) against 93 strains of rare pathogenic fungi and the combined effects of drug combinations against several multidrug-resistant fungi.Methodology. The broth microdilution method M38-A3 and M27-A4 from the Clinical and Laboratory Standards Institute and the checkerboard method were performed in this study.Results. Low MICs for fluconazole were observed in moulds including Tritirachium oryzae, Exophiala attenuata and yeasts. MICs for amphotericin B>2 µg ml-1 were found among Aspergillus nidulans, Fusarium napiforme, Trichoderma longibrachiatum, Tritirachium oryzae, Cunninghamella bertholletiae, Cunninghamella phaeospora, Conidiobolus coronatus, Exophiala attenuata, Ochroconis mirabilis and Rhinocladiella basitona. Multidrug resistance was observed in Microascus spp., Lomentospora prolificans and Pythium insidiosum.Conclusion. Our study illustrated in vitro drug susceptibilities of some rare pathogenic fungi, which provide data to guide clinical treatment of fungal infections.


Assuntos
Antifúngicos/farmacologia , Fungos/efeitos dos fármacos , Micoses/microbiologia , Anfotericina B/farmacologia , Farmacorresistência Fúngica , Fluconazol/farmacologia , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Humanos , Itraconazol/farmacologia , Testes de Sensibilidade Microbiana , Triazóis/farmacologia , Voriconazol/farmacologia
10.
Parasitol Res ; 118(10): 3067-3076, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31392413

RESUMO

This study is a report on the anti-Leishmania activity of Morita-Baylis-Hillman (MBH) homodimers adducts against the promastigote and axenic amastigote forms of Leishmania (Leishmania) infantum and Leishmania (Leishmania) amazonensis and on the cytotoxicity of these adducts to human blood cells. Both studied homodimers, MBH 1 and MBH 2, showed activity against the promastigote forms of L. infantum and L. amazonensis, which are responsible for visceral and cutaneous leishmaniasis, respectively. Additionally, the homodimers presented biological activity against the axenic amastigote forms of these two Leishmania species. The adducts exhibited no hemolytic activity to human peripheral blood mononuclear cells or erythrocytes at the tested concentrations and achieved higher selectivity indices than amphotericin B. Evaluation of cell death by apoptosis revealed that the homodimers had better apoptosis/necrosis profiles than amphotericin B in the promastigote forms of both L. infantum and L. amazonensis. In conclusion, these Morita-Baylis-Hillman adducts had anti-Leishmania activity in an in vitro model and may thus be promising molecules in the search for new drugs to treat leishmaniasis.


Assuntos
Antiprotozoários/síntese química , Antiprotozoários/farmacologia , Leishmania/efeitos dos fármacos , Anfotericina B/farmacologia , Animais , Antiprotozoários/química , Apoptose/efeitos dos fármacos , Dimerização , Avaliação Pré-Clínica de Medicamentos , Hemólise , Humanos , Leishmania/crescimento & desenvolvimento
11.
J Med Microbiol ; 68(10): 1479-1488, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31380734

RESUMO

Purpose. Fungal infections have increased in recent decades, with Candida albicans being the fourth most common aetiological agent of nosocomial infections. Disaccharide trehalose has been proposed as a target for the development of new antifungals. In C. albicans we have examined the susceptibility shown by two mutants deficient in trehalose biosynthesis, namely tps1Δ and tps2Δ, to amphotericin B (AmB) and micafungin (MF).Methodology. Minimum inhibitory concentrations (MICs) were calculated according to the Clinical and Laboratory Standards Institute (CLSI) criteria. Cell viability was assessed by cell counting. Intracellular reactive oxygen species (ROS) and the mitochondrial membrane potential were measured by flow cytometry, while the trehalose content and biofilm formation were determined by enzymatic assays.Results. While the tps1Δ mutant was highly sensitive to AmB exposure, its resistance to MF was similar to that of the wild-type. Notably, the opposite phenotype was recorded in the tps2Δ mutant. In turn, MF induced a significant level of endogenous ROS production in the parental SC5314 and tps2Δ cells, whereas the ROS formation in tps1Δ cells was virtually undetectable. The level of endogenous ROS correlated positively with the rise in mitochondrial activity. Only AmB was able to promote intracellular synthesis of trehalose in the parental strain; it was absent from tps1Δ cells and showed low levels in tps2Δ, confirming the unspecific dephosphorylation of trehalose-6P in C. albicans. Furthermore, the capacity of both tps1Δ and tps2Δ mutants to form biofilms was drastically reduced after AmB exposure, whereas it increased in tps1Δ cells treated with MF.Conclusion. Our data lend weight to the idea of using trehalose biosynthesis as a potential target for antifungal therapy.


Assuntos
Anfotericina B/farmacologia , Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Candida albicans/enzimologia , Proteínas Fúngicas/genética , Glucosiltransferases/genética , Micafungina/farmacologia , Trealose/biossíntese , Biofilmes/efeitos dos fármacos , Candida albicans/genética , Candida albicans/fisiologia , Candidíase/microbiologia , Proteínas Fúngicas/metabolismo , Glucosiltransferases/metabolismo , Humanos , Testes de Sensibilidade Microbiana , Espécies Reativas de Oxigênio/metabolismo , Deleção de Sequência
12.
Future Microbiol ; 14: 969-980, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31382783

RESUMO

Aim: A structural model of chorismate synthase (CS) from the pathogenic fungus Candida albicans was used for virtual screening simulations. Methods: Docking, molecular dynamics, cell growth inhibition and protein binding assays were used for search and validation. Results: Two molecules termed CS8 and CaCS02 were identified. Further studies of the minimal inhibitory concentration demonstrated fungicidal activity against Paracoccidioides brasiliensis with a minimal inhibitory concentration and minimal fungicidal concentration of 512 and 32 µg·ml-1 for CS8 and CaCS02, respectively. In addition, CaCS02 showed a strong synergistic effect in combination with amphotericin B without cytotoxic effects. In vitro studies using recombinant CS from P. brasiliensis showed IC50 of 29 µM for CaCS02 supporting our interpretation that inhibition of CS causes the observed fungicidal activity.


Assuntos
Antifúngicos/farmacologia , Proteínas Fúngicas/antagonistas & inibidores , Paracoccidioides/efeitos dos fármacos , Fósforo-Oxigênio Liases/antagonistas & inibidores , Sequência de Aminoácidos , Anfotericina B/farmacologia , Animais , Antifúngicos/química , Antifúngicos/metabolismo , Candida albicans/enzimologia , Sinergismo Farmacológico , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Células HeLa , Humanos , Concentração Inibidora 50 , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Estrutura Molecular , Paracoccidioides/enzimologia , Fósforo-Oxigênio Liases/química , Fósforo-Oxigênio Liases/metabolismo , Ligação Proteica , Células Vero
13.
J Mycol Med ; 29(3): 273-277, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31409527

RESUMO

Following a fatal case of Cryptococcus neoformans meningitis in a child with X-linked hyper-immunoglobulin M syndrome (XHIGM), we evaluated the fungal isolate in an experimental infection in a mouse model with respect to microbiology, epidemiology, virulence and response to therapy. The minimum inhibitory concentrations for antifungals in the susceptibility test were 0.5mg/L for amphotericin B, 4.0mg/L for fluconazole and 0.12mg/L for voriconazole. Evaluation of pathogenicity by means of an experimental infection in BALB/c mice showed that fungus isolated from the blood and cerebrospinal fluid of the child was able to disseminate, reaching the spleen, lungs and brain, where it caused significant macroscopic alterations in the size and texture of each organ. Treatment of infected mice with amphotericin B reduced the fungal load in the spleen and lungs, but not in the brain.


Assuntos
Cryptococcus neoformans/isolamento & purificação , Cryptococcus neoformans/patogenicidade , Síndrome de Imunodeficiência com Hiper-IgM Tipo 1/complicações , Síndrome de Imunodeficiência com Hiper-IgM Tipo 1/microbiologia , Meningite Criptocócica/diagnóstico por imagem , Meningite Criptocócica/microbiologia , Anfotericina B/farmacologia , Animais , Antifúngicos/farmacologia , Pré-Escolar , Cryptococcus neoformans/efeitos dos fármacos , Modelos Animais de Doenças , Evolução Fatal , Humanos , Síndrome de Imunodeficiência com Hiper-IgM Tipo 1/diagnóstico , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Tomografia Computadorizada por Raios X
14.
J Med Microbiol ; 68(10): 1489-1496, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31419209

RESUMO

Introduction. The remarkable intrinsic resistance of Fusarium species to most antifungal agents results in high mortality rates in the immunocompromised population.Aims. This study aimed to investigate the epidemiology, clinical features and antifungal susceptibility of Fusarium isolates in patients with invasive fusariosis.Methodology. A total of 27 patients admitted to a referral hospital from January 2008 to June 2017 were evaluated. Antifungal susceptibility testing of isolates was performed by broth microdilution according to the Clinical and Laboratory Standards Institute guidelines.Results. Haematological malignancy was the predominant underlying condition, with an incidence of invasive fusariosis of 14.8 cases per 1000 patients with acute lymphoid leukaemia and 13.1 cases per 1000 patients with acute myeloid leukaemia. The Fusarium solani species complex (FSSC) was the most frequent agent group, followed by the Fusarium oxysporum species complex (FOSC). Voriconazole showed the best activity against Fusarium, followed by amphotericin B. Itraconazole showed high minimum inhibitory concentration values, indicating in vitro resistance. Clinical FSSC isolates were significantly (P<0.05) more resistant to amphotericin B and voriconazole than FOSC isolates.Conclusion. The present antifungal susceptibility profiles indicate a high incidence of fusariosis in patients with haematological malignancy. Species- and strain-specific differences in antifungal susceptibility exist within Fusarium in this setting.


Assuntos
Fusariose/microbiologia , Fusarium/efeitos dos fármacos , Fusarium/isolamento & purificação , Neoplasias Hematológicas/microbiologia , Adolescente , Adulto , Idoso , Anfotericina B/farmacologia , Antifúngicos/farmacologia , Brasil/epidemiologia , Criança , Pré-Escolar , Feminino , Fusariose/epidemiologia , Fusarium/classificação , Fusarium/genética , Neoplasias Hematológicas/epidemiologia , Humanos , Itraconazol/farmacologia , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Filogenia , Voriconazol/farmacologia , Adulto Jovem
15.
Vet Microbiol ; 235: 43-52, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31282378

RESUMO

Even though it is widely known that Cryptococcus spp. may transmit cryptococcosis trough aerosol formed when dried birds (mainly pigeons) droppings are dispersed and become airborne, little is known about the role of these birds in harboring other pathogenic yeasts in their gastrointestinal tract, feathers and beaks, specifically because these animals often stay and reproduce close or even above air conditioner units. Here we evaluated the prevalence of pathogenic yeasts isolated from pigeon droppings collected in the outside area of a University Hospital in Brazil. We also aimed to investigate the pathogenic potential and antifungal susceptibility of Candida species of medical interest isolated from these samples. Therefore, we performed the evaluation of virulence factors attributes expression in vitro, including the ability to adhere to human buccal epithelial cells and biofilm formation and to produce lytic enzymes, such as phospholipases, proteinases and hemolysins. Antifungal susceptibility testing against fluconazole, itraconazole, amphotericin and micafungin was also performed. The Candida genus was the most prevalent in our study, with several medically important species being isolated. Of note, these strains were able to express several virulence factors in vitro, clearly showing their pathogenic potential. Our study was able to demonstrate that Candida spp. isolated from pigeon droppings may express virulence factors in the same manner of clinical isolates, suggesting a pathogenic potential for these yeasts. The fact these strains were collected from the outside area of a tertiary hospital may be of interest, because they may be a source of infection, specifically to immunocompromised hosts.


Assuntos
Antifúngicos/farmacologia , Azóis/farmacologia , Candida/efeitos dos fármacos , Columbidae/microbiologia , Farmacorresistência Fúngica , Fatores de Virulência/genética , Anfotericina B/farmacologia , Animais , Brasil , Candida/genética , Candida/isolamento & purificação , Criptococose/veterinária , Fezes/microbiologia , Fluconazol/farmacologia , Itraconazol/farmacologia , Testes de Sensibilidade Microbiana
16.
Cornea ; 38(10): 1314-1321, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31335527

RESUMO

PURPOSE: To evaluate a new corneal cold storage medium including an antimycotic tablet (Kerasave, AL.CHI.MI.A. S.r.l.). METHODS: Kerasave and tryptone soy broth (control) were inoculated with 10 and 10 colony-forming units (CFU)/mL of 6 Candida isolates (Candida albicans [n = 4], Candida tropicalis [n = 1], and Candida glabrata [n = 1]). Minimum inhibitory concentrations (MICs) were determined using amphotericin B Etest strips. Sterile porcine corneas contaminated with 10 CFU/mL of each isolate were incubated in Kerasave and control at 4°C. Growth rate and Log10 reduction at 4°C at different time intervals were determined for liquid samples and tissue homogenates. Kerasave biocompatibility was assessed according to ISO 10993-5 and ISO 10993-10. RESULTS: No C. albicans or C. tropicalis colonies were recovered from Kerasave inoculated with 10 CFU/mL after incubation for 3 days at 4°C. C. glabrata was inhibited but not killed after 3 days at 4°C. Four of the 6 strains contaminated with 10 CFU/mL demonstrated a significant ≥ 3 Log10 reduction in media and tissue homogenates within 5 days as compared to controls (p < 0.01). Amphotericin B MICs ranged from 0.19 to 0.38 µg/mL for C. albicans (n = 3) and C. tropicalis (n = 1). C. glabrata showed reduced susceptibility (0.5 µg/mL) and 1 C. albicans was resistant to amphotericin B (≥ 1 µg/mL). Kerasave was not cytotoxic, irritating, or sensitizing according to the ISO standards. CONCLUSIONS: Kerasave showed high antifungal efficacy against susceptible fungal strains at 4°C in the presence and absence of corneal tissue. Resistant strains to amphotericin B were not eliminated by Kerasave. Kerasave is not cytotoxic, irritating, or sensitizing.


Assuntos
Anfotericina B/farmacologia , Candida/efeitos dos fármacos , Candidíase/tratamento farmacológico , Córnea/efeitos dos fármacos , Infecções Oculares Fúngicas/tratamento farmacológico , Ceratite/tratamento farmacológico , Soluções para Preservação de Órgãos/farmacologia , Animais , Antifúngicos/farmacologia , Candida/isolamento & purificação , Candidíase/diagnóstico , Candidíase/microbiologia , Córnea/diagnóstico por imagem , Modelos Animais de Doenças , Infecções Oculares Fúngicas/diagnóstico , Infecções Oculares Fúngicas/microbiologia , Ceratite/diagnóstico , Ceratite/microbiologia , Testes de Sensibilidade Microbiana , Preservação de Órgãos/métodos , Suínos
17.
Int J Antimicrob Agents ; 54(3): 301-308, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31279153

RESUMO

Approximately 180,000 people worldwide die from cryptococcosis each year, probably due to the ineffectiveness and toxicity of drugs currently available to treat the disease. Amphotericin B (AMB) is effective for killing the fungus, but has serious adverse effects linked to excessive production of reactive oxygen species which compromise renal function. Pioglitazone (PIO) is a peroxisome proliferator-activated receptor-γ agonist widely repositioned as an adjuvant of various drugs that have toxic effects due to its antioxidant and anti-inflammatory effects. This study evaluated PIO in combination with AMB for the treatment of cryptococcosis. PIO was found to reduce serum creatinine and glutamic-oxalacetic transaminase levels in mice treated with PIO+AMB. In vitro, PIO was able to control harmful oxidative bursts induced by AMB without compromising the antifungal effect. In vivo, PIO+AMB increased the survival rate compared with AMB alone, and improved the morbidity of the animals. PIO+AMB was more efficient than AMB alone for inhibiting fungal transmigration from the lungs to the brain, and killing yeasts that reached the central nervous system, avoiding the establishment of meningoencephalitis. In a phagocytosis assay, PIO did not influence the engulfment and fungicidal activity of macrophages induced by AMB, but reduced the oxidative bursts after the reduction of fungal burden, pointing to control of the pathogen without leading to excessive stress which can be damaging to the host. In conclusion, PIO+AMB was found to ameliorate cryptococcosis in a murine model, indicating that it is a promising therapeutic adjuvant for combating and controlling this fungal infection.


Assuntos
Anfotericina B/administração & dosagem , Antifúngicos/administração & dosagem , Antioxidantes/administração & dosagem , Criptococose/tratamento farmacológico , Pioglitazona/administração & dosagem , Anfotericina B/farmacologia , Animais , Antifúngicos/farmacologia , Antioxidantes/farmacologia , Criptococose/patologia , Cryptococcus gattii/efeitos dos fármacos , Modelos Animais de Doenças , Reposicionamento de Medicamentos , Quimioterapia Combinada/métodos , Camundongos Endogâmicos C57BL , Pioglitazona/farmacologia , Análise de Sobrevida , Resultado do Tratamento
18.
BMC Infect Dis ; 19(1): 593, 2019 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-31286895

RESUMO

BACKGROUND: Current drug regimens for cutaneous leishmaniasis (CL) include toxic systemic therapies such as amphotericin B (AB) and pentavalent antimonials. Fluconazole (FZ) is a well-tolerated potential oral alternative for the management CL. To date, few objective data exist to guide clinical decision-making when selecting a therapeutic agent a priori, and standardized, clinically-approved drug susceptibility testing platforms for Leishmania spp. have yet to be established. The Sensititre™ YeastOne™ YO9 plate is a commercialized drug susceptibility plate including AB and FZ used for routine testing of non-fastidious yeast. Our objective was to adapt the readily available Sensititre™ YeastOne™ YO9 plate, to determine drug susceptibility profiles of AB and FZ in cultured isolates of Old World and New World Leishmania spp. for the treatment of CL. METHODS: Promastigotes were cultured in Tobie's medium with Locke's overlay until log phase growth was achieved, inoculated into the Sensititre™ system, and incubated over 96 H. minimum inhibitory concentrations (MICs) were determined colorimetrically, and promastigote death was assessed by conventional microscopy out to 96- h. Colour change correlated to MIC values. RESULTS: All strains tested exhibited MIC values for FZ that were ≥ 256 µg/mL. New World strains demonstrated reduced susceptibility to AB (0.25 µg/mL - 0.50 µg/mL AB) compared to Old World strains at 0.12 µg/mL AB (p = 0.02). Seventeen (61%) of 28 Viannia isolates versus 82% (27/33) of non-Viannia isolates were resistant at 0.12 µg/mL AB (p = 0.09). For L. V. braziliensis isolates, mean MIC for AB was 0.375 ± 0.14 µg/mL (range 0.25-0.50 µg/mL), while for isolates of L. V. panamensis it was 0.314 ± 0.26 µg/mL (range 0.12-1.0 µg/mL). CONCLUSIONS: We adapted the Sensititre™ YeastOne™ YO9 plate for testing of Leishmania spp. susceptibility profiles for commonly used antifungals in the treatment of CL, including AB and FZ. Given its current utility in mycology, optimization of the system for potential clinical implementation in parasitology should be pursued. However evaluation of clinically relevant amastigote-stage stages, and higher concentrations of FZ beyond the upper limit concentration of the Sensititre™ YeastOne™ Y09 plate would be required.


Assuntos
Anfotericina B/farmacologia , Fluconazol/farmacologia , Leishmania/efeitos dos fármacos , Testes de Sensibilidade Parasitária/métodos , Humanos , Leishmaniose/parasitologia , Testes de Sensibilidade Microbiana
19.
Free Radic Res ; 53(6): 618-628, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31185751

RESUMO

With a significant increase in the incidence of system invasive fungal infections, the limited antifungal drugs and increased frequency of cross-resistance make it necessary to explore new and effective therapeutic strategies. Combination drug therapy has become one widely used choice to alleviate this problem. Geldanamycin (GdA), as an inhibitor of Hsp90, displayed broad antifungal activity when combined with fluconazole. However, due to its cytotoxicity, the dose and duration of GdA is limited. In this study, we observed the effect of fluconazole plus GdA on Candida tropicalis resistant to azoles and amphotericin B. The results showed that this synergism led to a decrease in growth and survival rate. In addition, fluconazole combined with GdA caused mitochondrial depolarisation, disruption of plasma membrane integrity and multinucleated morphology. However, the supplement of a reactive oxygen species (ROS) scavenger, N-acetylcysteine (NAC), rescued the above phenotypes. This study indicated that the oxidative stress mediated by fluconazole plus GdA played an important role in the antifungal activity, and targeting oxidative stress might extend target choices to treat fungal infections.


Assuntos
Antifúngicos/farmacologia , Benzoquinonas/farmacologia , Candida tropicalis/efeitos dos fármacos , Farmacorresistência Fúngica/efeitos dos fármacos , Fluconazol/farmacologia , Lactamas Macrocíclicas/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Anfotericina B/farmacologia , Antifúngicos/química , Azóis/farmacologia , Candida tropicalis/crescimento & desenvolvimento , Candida tropicalis/metabolismo , Testes de Sensibilidade Microbiana , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Estresse Oxidativo/efeitos dos fármacos
20.
Appl Microbiol Biotechnol ; 103(16): 6701-6709, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31201451

RESUMO

Candida albicans causes a high mortality rate in immunocompromised individuals, but the increased drug resistance challenges the current antifungal therapeutics. Fluphenazine (FPZ), a commonly used antipsychotic medication, can induce the expression of drug efflux pumps in C. albicans and, thus, may interfere with the therapeutic efficacy of antifungals, such as fluconazole (FLC) and amphotericin B (AmB). Here, we investigated the combined effects of FLC/FPZ and AmB/FPZ against C. albicans in vitro and in a systemic candidiasis mouse model. The antifungal activity of FLC was significantly reduced when supplemented with FPZ. The inhibitory effects of FLC on the expression of the Candida virulence-related genes ALS3 and HWP1 were antagonized by FPZ. However, FPZ enhanced the susceptibility of C. albicans to AmB and further downregulated the expression of ALS3 and HWP1 in a synergistic manner with AmB. FPZ also enhanced the gene expression of ERG11, a key gene of the ergosterol biosynthesis pathway that has been associated with the activities of both FLC and AmB. In our mammalian infection model, mice treated with FLC/FPZ showed notably poor living status and increased fungal burden in their kidneys and brains compared with those treated with FLC alone. Conversely, the combined application of AmB/FPZ significantly improved the survival rate, attenuated the weight loss and reduced the organ fungal burdens of the infected mice. These data suggest that FPZ antagonized the therapeutic efficacy of FLC but enhanced the antifungal activity of AmB in the treatment of candidiasis.


Assuntos
Anfotericina B/farmacologia , Antifúngicos/farmacologia , Antipsicóticos/farmacologia , Candida albicans/efeitos dos fármacos , Interações de Medicamentos , Fluconazol/farmacologia , Flufenazina/farmacologia , Anfotericina B/administração & dosagem , Estruturas Animais , Animais , Antifúngicos/administração & dosagem , Antipsicóticos/administração & dosagem , Candidíase/tratamento farmacológico , Contagem de Colônia Microbiana , Modelos Animais de Doenças , Fluconazol/administração & dosagem , Flufenazina/administração & dosagem , Perfilação da Expressão Gênica , Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Camundongos , Resultado do Tratamento
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