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1.
J Med Microbiol ; 70(9)2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34491156

RESUMO

Introduction. The increase of invasive fungal infections (IFIs) and associated treatment failure in populations at risk is driving us to look for new treatments.Hypothesis. The CIN-102 compound, derived from cinnamon essential oil, could be a new antifungal class with an activity, in particular, on strains resistant to current antifungals but also on biofilms, a factor of virulence and resistance of fungi.Aim. The aim of this study is to show the activity of CIN-102 on various strains resistant to current antifungals, on the biofilm and to determine the possibility of resistance induced with this compound.Methodology. We studied the MIC of CIN-102 and of current antifungals (voriconazole and amphotericin B) using CLSI techniques against eight different strains of three genera of filamentous fungi involved in IFIs and having resistance phenotypes to current antifungals. We also determined their effects on biofilm formation, and the induced resistance by voriconazole (VRC) and CIN-102.Results. MIC values determined for CIN-102 were between 62.5 and 250 µg ml-1. We demonstrated the antifungal effect of CIN-102 on biofilm, and more particularly on its formation, with 100 % inhibition achieved for most of the strains. CIN-102 at a sub-inhibitory concentration in the medium did not induce resistance in our strains, even after 30 generations.Conclusions. In this study we show that CIN-102 is effective against resistant filamentous fungi and against biofilm formation. In addition, our strains did not acquire a resistance phenotype against CIN-102 over time, unlike with VRC. CIN-102 is therefore an interesting candidate for the treatment of IFIs, including in cases of therapeutic failure linked to resistance, although further studies on its efficacy, safety and mechanism of action are needed.


Assuntos
Antifúngicos/farmacologia , Benzoatos/farmacologia , Biofilmes/efeitos dos fármacos , Cinamatos/farmacologia , Fungos/efeitos dos fármacos , Micoses , Terpenos/farmacologia , Anfotericina B/farmacologia , Combinação de Medicamentos , Humanos , Testes de Sensibilidade Microbiana , Micoses/tratamento farmacológico , Micoses/microbiologia , Voriconazol/farmacologia
2.
Artigo em Inglês | MEDLINE | ID: mdl-34520340

RESUMO

The fungal pathogen Botrytis cinerea is the causal agent of devastating gray mold diseases in many economically important fruits, vegetables, and flowers, leading to serious economic losses worldwide. In this study, a novel actinomycete NEAU-LD23T exhibiting antifungal activity against B. cinerea was isolated, and its taxonomic position was evaluated using a polyphasic approach. Based on the genotypic, phenotypic and chemotaxonomic data, it is concluded that the strain represents a novel species within the genus Streptomyces, for which the name Streptomyces botrytidirepellens sp. nov. is proposed. The type strain is NEAU-LD23T (=CCTCC AA 2019029T=DSM 109824T). In addition, strain NEAU-LD23T showed a strong antagonistic effect against B. cinerea (82.6±2.5%) and varying degrees of inhibition on nine other phytopathogenic fungi. Both cell-free filtrate and methanol extract of mycelia of strain NEAU-LD23T significantly inhibited mycelial growth of B. cinerea. To preliminarily explore the antifungal mechanisms, the genome of strain NEAU-LD23T was sequenced and analyzed. AntiSMASH analysis led to the identification of several gene clusters responsible for the biosynthesis of bioactive secondary metabolites with antifungal activity, including 9-methylstreptimidone, echosides, anisomycin, coelichelin and desferrioxamine B. Overall, this research provided us an excellent strain with considerable potential to use for biological control of tomato gray mold.


Assuntos
Actinobacteria , Streptomyces , Antifúngicos/farmacologia , Técnicas de Tipagem Bacteriana , Composição de Bases , Botrytis , DNA Bacteriano/genética , Ácidos Graxos/química , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Streptomyces/genética
3.
West Afr J Med ; 38(8): 743-748, 2021 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-34499919

RESUMO

BACKGROUND: Candida albicans and non-albicans Candida species are considered as commensal yeasts of many cavities including the external auditory canal (EAC) in healthy individuals. These fungal microorganisms can also act as opportunist pathogens and cause otomycosis. In this study, the patients of clinically suspected otomycosis were specifically investigated mycologically to elucidate the role of Candida albicans and non-albicans Candida species. MATERIAL AND METHODS: A prospective observational study was conducted from July 2016 and June 2017 at the Laboratory of Parasitology and Mycology of the Sourô SANOU University Hospital in Bobo-Dioulasso, Burkina Faso. Identification of Candida isolates was using conventional phenotypic methods. Antifungal susceptibility tests were carried out by disk diffusion method in accordance with CLSI standard document M44-A for yeasts. RESULTS: Out of 160 patients with clinically diagnosed otomycosis, 77(48.1%) were investigated positive for Candida species. Candida albicans (61%) was the most isolated species and non-albicans Candida species accounted for 39% of the isolates, with mainly Candida spp (22.1%), Candida krusei (10.4%), Candida dubliniensis (5.2%) and Candida glabrata (1.3%). Nystatin showed the highest efficacy (95.9%), followed by ketoconazole (90.4%), clotrimazole (83.6%), miconazole (72.6%) and amphotericin B (63.0%). CONCLUSION: Otomycosis due to Candida species should be especially considered, since they have a wide number of potential virulence factors that cause fungal infections. Also, antifungal susceptibility testing should be performed in order to select the appropriate antifungal therapy.


Assuntos
Candida albicans , Otomicose , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Candida , Farmacorresistência Fúngica , Fluconazol , Humanos , Testes de Sensibilidade Microbiana , Otomicose/diagnóstico , Otomicose/tratamento farmacológico , Pichia
4.
Appl Microbiol Biotechnol ; 105(18): 6871-6886, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34477940

RESUMO

Aspergillus flavus is a notorious saprophytic fungus that compromises the quantity and quality of postharvest grains and produces carcinogenic aflatoxins. The natural compound hexanal disrupts cell membrane synthesis and mitochondrial function and induces apoptosis in A. flavus; here, we investigated the molecular mechanisms underlying these effects. The minimum inhibition and fungicidal concentration (MIC and MFC) of hexanal against A. flavus spores were 3.2 and 9.6 µL/mL, respectively. Hexanal exposure resulted in abnormal spore morphology and early spore apoptosis. These changes were accompanied by increased reactive oxygen species production, reduced mitochondrial membrane potential, and DNA fragmentation. Transcriptomic analysis revealed that hexanal treatment greatly altered the metabolism of A. flavus spores, including membrane permeability, mitochondrial function, energy metabolism, DNA replication, oxidative stress, and autophagy. This study provides novel insights into the mechanism underlying the antifungal activity of hexanal, suggesting that hexanal can be used an anti-A. flavus agent for agricultural applications. KEY POINTS: • Hexanal exposure resulted in abnormal spore morphology. • The apoptotic characteristics of A. flavus were induced after hexanal treatment. • Hexanal could change the expression of key A. flavus growth-related genes.


Assuntos
Aflatoxinas , Aspergillus flavus , Aflatoxinas/metabolismo , Aldeídos , Antifúngicos/metabolismo , Antifúngicos/farmacologia , Apoptose , Mitocôndrias , Esporos Fúngicos/metabolismo
5.
Zhongguo Zhong Yao Za Zhi ; 46(15): 3877-3885, 2021 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-34472263

RESUMO

Twenty-six compounds, including sixteen meroterpenoids(1-16), a triterpenoid(17), four terpenoid derivatives(18-21), and five aromatic compounds(22-26), were isolated from the leaves of Psidium guajava. Their structures were identified by spectroscopic analyses including NMR and MS. Compounds 21-26 were obtained from plants of Psidium for the first time. Based on the structure,(R)-2-ethylhexyl 2H-1,2,3-triazole-4-carboxylate(24 a), an α-glucosidase inhibitor recently isolated from Paramignya trimera, should be revised as compound 24. Meroterpenoids 1-16 were evaluated for their antitumor and antifungal activities. Meroterpenoids psiguajadial D(4), guapsidial A(5), 4,5-diepipsidial A(7), guadial A(14), and guadial B(15) showed cytotoxicities against five human tumor cell lines(HL-60, A-549, SMMC-7721, MCF-7, and SW-480), among which 5 was the most effective with an IC_(50) of 3.21-9.94 µmol·L~(-1).


Assuntos
Psidium , Antifúngicos/farmacologia , Humanos , Espectroscopia de Ressonância Magnética , Extratos Vegetais , Folhas de Planta , Terpenos
6.
J Assoc Physicians India ; 69(8): 11-12, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34472809

RESUMO

INTRODUCTION: Candidemia is the fourth common cause of blood stream infection worldwide leading to increased mortality and morbidity. A paradigm shift of Candida albicans to Non-albicans candida (NAC) had led to the increase in resistance to empirically used antifungals. So, an epidemiological study and antifungal susceptibility is essential for meticulous use of antifungals. AIMS AND OBJECTIVES: To find out the prevalence and antifungal susceptibility of Candida species causing candidemia. METHODS: automated blood culture done in BACTEC system followed by its identification and susceptibility testing in VITEK-2 system. RESULTS: Non-albicans candida was isolated from 73% cases of candidemia. The commonest isolate among neonates and adults were C.krusei and C.tropicalis respectively. C.haemulonii was significantly high among adult population while C.krusei was significantly high among the neonates. 10.4% NAC isolates were resistant to amphotericin B, flucytosine resistance among 37% NAC isolates and among 44% C.albicans isolates, fluconazole resistance was found among 13% and 15% of NAC and C. albicans respectively. Echinocandins were comparatively sensitive to the candida spp.


Assuntos
Candida , Candidemia , Adulto , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Candidemia/tratamento farmacológico , Candidemia/epidemiologia , Fluconazol/farmacologia , Humanos , Índia/epidemiologia , Recém-Nascido , Testes de Sensibilidade Microbiana
7.
Mater Sci Eng C Mater Biol Appl ; 128: 112327, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34474878

RESUMO

Chitosan oligosaccharide (COS), a time-dependent antimicrobial carbohydrate, is found antifungal active with a short duration of action due to excessive solubility. We attempted to address this issue by employing a hydrogel as a COS carrier. In this research, macroporous zwitterionic composite cryogels composed of COS and poly(N-methacryl arginine) (PMarg) were fabricated, serving as long-term antifungal dressings. Firstly, Marg was synthesized and characterized by Fourier transform infrared spectroscopy (FT-IR), 1H and 13C nuclear magnetic resonance (NMR), and high-resolution mass spectrometry (HRMS). Then, the COS/PMarg cryogels were prepared by redox initiation cryopolymerization. The macroporous morphology of the cryogels was confirmed by scanning electron microscope (SEM) with pore size varying from 20.86 to 50.87 µm. FTIR indicated that hydrogen bonding formed between COS and PMarg, and the interaction elevated thermal stability of the cryogels as evidenced by thermal-gravimetric analysis (TGA). Swelling capacity, mechanical properties, and COS release behavior of the COS/PMarg cryogels were investigated. With the release of COS, the antifouling activity of the cryogel increased. Antimicrobial tests indicated the COS/PMarg cryogel could effectively inhibit the proliferation of Candida albicans. It demonstrated that the macroporous zwitterionic COS/PMarg composite cryogel might be a potential antifungal dressing with sequential "sterilization-release" capacity.


Assuntos
Quitosana , Criogéis , Antifúngicos/farmacologia , Oligossacarídeos , Porosidade , Espectroscopia de Infravermelho com Transformada de Fourier
8.
J Agric Food Chem ; 69(36): 10527-10535, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34469148

RESUMO

In the search for new natural resources showing plant disease control effects, we found that the methanol extract of Polyalthia longifolia suppressed fungal disease development in plants. To identify the bioactive substances, the methanol extract of P. longifolia was extracted by organic solvents, and consequently, four new 2-oxo-clerodane diterpenes (1-4), a new 4(3 → 2)-abeo-clerodane diterpene (5), together with ten known compounds (6-16) were isolated and identified from the extracts. Of the new compounds, compound 2 showed a broad spectrum of antifungal activity with moderated minimum inhibitory concentration (MIC) values in a range of 50-100 µg/mL against tested fungal pathogens. Considering with the known compounds, compound 6 showed the most potent antifungal activity with an MIC value in the range of 6.3-12.5 µg/mL. When compound 6 was evaluated for an in vivo antifungal activity against rice blast, tomato late blight, and pepper anthracnose, compound 6 reduced the plant disease by at least 60% compared to the untreated control at concentrations of 250 and 500 µg/mL. Together, our results suggested that the methanol extract of twigs and leaves of P. longifolia and its major compound 6 could be used as a source for the development of eco-friendly plant protection agents.


Assuntos
Diterpenos Clerodânicos , Polyalthia , Antifúngicos/farmacologia , Diterpenos Clerodânicos/farmacologia , Testes de Sensibilidade Microbiana , Extratos Vegetais/farmacologia , Folhas de Planta
9.
J Agric Food Chem ; 69(36): 10709-10721, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34476938

RESUMO

Thirty-one new 4H-chromene derivatives were designed and synthesized. Their structures were identified with IR, 1H NMR, 13C NMR, and HRMS. The crystal structure of compound 2a was determined by single-crystal X-ray diffraction. Their antifungal activities were evaluated against Pyricularia oryzae, Erysiphe graminis, Coniella diplodiella, Pseudoperonospora cubensis, and Sclerotinia sclerotiorum. These results demonstrated that most compounds exhibited remarkable inhibitory activities at 20 µg/mL. Compounds 4b and 4c displayed excellent antifungal activity against S. sclerotiorum and possessed better efficacy than fluopyram. At the same time, the inhibitory activity of the bioactive compounds was evaluated against succinate dehydrogenase (SDH). The results showed that these compounds possessed outstanding activity. Compounds 4b and 4c displayed better inhibitory activity than fluopyram. The molecular modeling results revealed that compound 4c had stronger affinity to SDH than fluopyram. It is the first time that the inhibitory activity of 4H-chromene analogs against SDH has been reported.


Assuntos
Benzopiranos , Succinato Desidrogenase , Antifúngicos/farmacologia , Ascomicetos , Benzopiranos/farmacologia , Estrutura Molecular , Relação Estrutura-Atividade , Succinato Desidrogenase/metabolismo
10.
Comput Biol Med ; 136: 104722, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34358995

RESUMO

BACKGROUND: Mucormycosis, a fungal infection caused by Rhizopus species is on the rise in COVID-19 patients as a result of their suppressed immunity. The current therapies include systemic administration of Amphotericin B. HYPOTHESIS AND METHOD: We screened several triazole broad-spectrum antifungal agents against the therapeutic target in mucormycosis using computational techniques like molecular docking and compared them with isavuconazole, an approved drug. RESULT: The study concluded that 4 triazole drugs, pramiconazole, itraconazole, posaconazole and ketoconazole were strong candidates to be further evaluated and developed as a treatment for mucormycosis. CONCLUSION: Novel topical and oral therapies could be developed from these drug leads.


Assuntos
COVID-19 , Mucormicose , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Reposicionamento de Medicamentos , Humanos , Simulação de Acoplamento Molecular , Mucormicose/tratamento farmacológico , SARS-CoV-2 , Triazóis/farmacologia
11.
Molecules ; 26(15)2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34361545

RESUMO

In this study, using the botanical active component thiochromanone as the lead compound, a total of 32 new thiochromanone derivatives containing a carboxamide moiety were designed and synthesized and their in vitro antibacterial activities against Xanthomonas oryzae pv. oryzae (Xoo), Xanthomonas oryzae pv. oryzicolaby (Xoc), and Xanthomonas axonopodis pv. citri (Xac) were determined, as well as their in vitro antifungal activities against Botryosphaeria dothidea (B. dothidea), Phomopsis sp., and Botrytis cinerea (B. cinerea). Bioassay results demonstrated that some of the target compounds exhibited moderate to good in vitro antibacterial and antifungal activities. In particular, compound 4e revealed excellent in vitro antibacterial activity against Xoo, Xoc, and Xac, and its EC50 values of 15, 19, and 23 µg/mL, respectively, were superior to those of Bismerthiazol and Thiodiazole copper. Meanwhile, compound 3b revealed moderate in vitro antifungal activity against B. dothidea at 50 µg/mL, and the inhibition rate reached 88%, which was even better than that of Pyrimethanil, however, lower than that of Carbendazim. To the best of our knowledge, this is the first report on the antibacterial and antifungal activities of this series of novel thiochromanone derivatives containing a carboxamide moiety.


Assuntos
Botrytis/crescimento & desenvolvimento , Cromanos , Phomopsis/crescimento & desenvolvimento , Xanthomonas axonopodis/crescimento & desenvolvimento , Xanthomonas/crescimento & desenvolvimento , Antifúngicos/síntese química , Antifúngicos/química , Antifúngicos/farmacologia , Cromanos/síntese química , Cromanos/química , Cromanos/farmacologia , Relação Estrutura-Atividade
12.
Molecules ; 26(15)2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34361552

RESUMO

Postharvest pathogens such as C. gloeosporioides (MA), C.oxysporum (ME) and P. steckii (MF) are the causal agents of disease in mangoes. This paper presents an in vitro investigation into the antifungal effect of a chitosan (CTS)/nano-titanium dioxide (TiO2) composite coating against MA, ME and MF. The results indicated that, the rates of MA, ME and MF mortality following the single chitosan treatment were 63.3%, 84.8% and 43.5%, respectively, while the rates of mycelial inhibition were 84.0%, 100% and 25.8%, respectively. However, following the addition of 0.5% nano-TiO2 into the CTS, both the mortality and mycelial inhibition rates for MA and ME reached 100%, and the mortality and mycelial inhibition rate for MF also increased significantly, reaching 75.4% and 57.3%, respectively. In the MA, the dry weight of mycelia after the CTS/0.5% nano-TiO2 treatment decreased by 36.3% in comparison with the untreated group, while the conductivity value was about 1.7 times that of the untreated group, and the protein dissolution rate and extravasation degree of nucleic acids also increased significantly. Thus, this research revealed the potential of CTS/nano-TiO2 composite coatings in the development of new antimicrobial materials.


Assuntos
Antifúngicos , Quitosana , Colletotrichum/crescimento & desenvolvimento , Nanocompostos , Titânio , Antifúngicos/química , Antifúngicos/farmacologia , Quitosana/química , Quitosana/farmacologia , Mangifera/microbiologia , Nanocompostos/química , Nanocompostos/uso terapêutico , Doenças das Plantas/microbiologia , Titânio/química , Titânio/farmacologia
13.
Molecules ; 26(16)2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34443412

RESUMO

Palmarosa essential oil (PEO) is an alternative to synthetic fungicides to control the contamination by food-deteriorating fungi, such as Aspergillus nomius. Nonetheless, the low long-term stability and volatility hamper its utilization. Thus, this study aimed to develop nanostructured lipid carriers (NLCs) containing PEO to improve its stability and consequently prolong the activity against A. nomius. A mixture design was applied to find the best preparation conditions for antifungal activity. The characterization analyses included size measurements, zeta potential (ζ-potential), entrapment efficiency (EE), and antifungal activity (by inhibition of mycelial growth (IMG) and/or in situ test (pre-contaminated Brazil nuts) tests). The nanocarriers presented particle sizes smaller than 300 nm, homogeneous size distribution, ζ-potential of -25.19 to -41.81 mV, and EE between 73.6 and 100%. The formulations F5 and F10 showed the highest IMG value (98.75%). Based on the regression model, three optimized formulations (OFs) were tested for antifungal activity (IMG and in situ test), which showed 100% of inhibition and prevented the deterioration of Brazil nuts by A. nomius. The preliminary stability test showed the maintenance of antifungal activity and physicochemical characteristics for 90 days. These results suggest a promising system as a biofungicide against A. nomius.


Assuntos
Aspergillus/efeitos dos fármacos , Cymbopogon/química , Portadores de Fármacos/química , Nanoestruturas/química , Óleos Voláteis/farmacologia , Antifúngicos/farmacologia , Bertholletia/microbiologia , Composição de Medicamentos , Cromatografia Gasosa-Espectrometria de Massas , Testes de Sensibilidade Microbiana , Nanoestruturas/ultraestrutura , Tamanho da Partícula , Espectroscopia de Infravermelho com Transformada de Fourier , Eletricidade Estática
14.
Molecules ; 26(16)2021 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-34443447

RESUMO

Okara is a soybean transformation agri-food by-product, the massive production of which currently poses severe disposal issues. However, its composition is rich in seed storage proteins, which, once extracted, can represent an interesting source of bioactive peptides. Antimicrobial and antifungal proteins and peptides have been described in plant seeds; thus, okara is a valuable source of compounds, exploitable for integrated pest management. The aim of this work is to describe a rapid and economic procedure to isolate proteins from okara, and to produce an enzymatic proteolyzed product, active against fungal plant pathogens. The procedure allowed the isolation and recovery of about 30% of okara total proteins. Several proteolytic enzymes were screened to identify the proper procedure to produce antifungal compounds. Antifungal activity of the protein digested for 24 h with pancreatin against Fusarium and R. solani mycelial growth and Pseudomonas spp was assessed. A dose-response inhibitory activity was established against fungi belonging to the Fusarium genus. The exploitation of okara to produce antifungal bioactive peptides has the potential to turn this by-product into a paradigmatic example of circular economy, since a field-derived food waste is transformed into a source of valuable compounds to be used in field crops protection.


Assuntos
Antifúngicos/farmacologia , Enzimas/metabolismo , Proteínas de Plantas/metabolismo , Plantas/microbiologia , Polissacarídeos/metabolismo , Liofilização , Fusarium/efeitos dos fármacos , Fusarium/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Peso Molecular , Proteólise/efeitos dos fármacos , Alimentos de Soja , Espectrofotometria Ultravioleta , Tripsina/metabolismo , Inibidores da Tripsina/farmacologia
15.
Int J Mol Sci ; 22(15)2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-34360998

RESUMO

Candida albicans, an opportunistic fungus, causes dental caries and contributes to mucosal bacterial dysbiosis leading to a second infection. Furthermore, C.albicans forms biofilms that are resistant to medicinal treatment. To make matters worse, antifungal resistance has spread (albeit slowly) in this species. Thus, it has been imperative to develop novel, antifungal drug compounds. Herein, a peptide was engineered with the sequence of RRFSFWFSFRR-NH2; this was named P19. This novel peptide has been observed to exert disruptive effects on fungal cell membrane physiology. Our results showed that P19 displayed high binding affinity to lipopolysaccharides (LPS), lipoteichoic acids (LTA) and the plasma membrane phosphatidylinositol (PI), phosphatidylserine (PS), cardiolipin, and phosphatidylglycerol (PG), further indicating that the molecular mechanism of P19 was not associated with the receptor recognition, but rather related to competitive interaction with the plasma membrane. In addition, compared with fluconazole and amphotericin B, P19 has been shown to have a lower potential for resistance selection than established antifungal agents.


Assuntos
Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Oligopeptídeos/farmacologia , Antifúngicos/química , Candida albicans/fisiologia , Cardiolipinas/metabolismo , Membrana Celular/efeitos dos fármacos , Lipopolissacarídeos/metabolismo , Oligopeptídeos/química , Fosfatidilgliceróis/metabolismo , Fosfatidilinositóis/metabolismo , Fosfatidilserinas/metabolismo , Ácidos Teicoicos/metabolismo , Triptofano/química
16.
Appl Microbiol Biotechnol ; 105(18): 6559-6578, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34453564

RESUMO

The Caatinga is an exclusively Brazilian biome where semiarid climatic conditions promote singularities in adaptive biodiversity. Many aromatic species are found in this region possessing antifungal properties, which are attributed to their essential oils. Thus, we questioned whether essential plant oils found in the Caatinga present anti-dermatophytic potential. Dermatophytes are keratinophilic fungi that cause one of the most prevalent mycoses globally, skin infections known as dermatophytoses (tineas). Here, we provide a comprehensive report of the available published information, analyzing the methods used to evaluate the antifungal activity, verifying the quality of the evidence and possible clinical applications, and discussing research trends in this area. The plants studied concentrated in the genera Croton (Euphorbiaceae), Lippia (Verbenaceae), Piper (Piperaceae), and Mentha (Lamiaceae). All of the studies used in vitro tests to analyze antifungal potential, and little evidence was ascertained concerning the mechanism of antifungal action. In addition, the essential oils also evidenced drug modifying activity of conventional antifungal drugs (Ketoconazole and Terbinafine). We believe that the anti-dermatophyte potential of plant essential oils occurring within the Caatinga is underestimated and that this review will encourage future chemical-pharmacological investigations into the plants within this biome.Key points• The essential oils from plants occurring in the Caatinga Biome present unknown anti-dermatophyte potential.• The studies against dermatophyte fungi concentrate on the families Lamiaceae and Verbenaceae.• In vitro assays were used to assess the anti-dermatophyte potential of the essential oils.


Assuntos
Óleos Voláteis , Tinha , Antifúngicos/farmacologia , Ecossistema , Humanos , Testes de Sensibilidade Microbiana , Óleos Voláteis/farmacologia , Óleos Vegetais
17.
Molecules ; 26(16)2021 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-34443320

RESUMO

Crop diseases caused by Fusarium pathogens, among other microorganisms, threaten crop production in both commercial and smallholder farming. There are increasing concerns about the use of conventional synthetic fungicides due to fungal resistance and the associated negative effects of these chemicals on human health, livestock and the environment. This leads to the search for alternative fungicides from nature, especially from plants. The objectives of this study were to characterize isolated compounds from Combretum erythrophyllum (Burch.) Sond. and Withania somnifera (L.) Dunal leaf extracts, evaluate their antifungal activity against Fusarium pathogens, their phytotoxicity on maize seed germination and their cytotoxicity effect on Raw 264.7 macrophage cells. The investigation led to the isolation of antifungal compounds characterized as 5-hydroxy-7,4'-dimethoxyflavone, maslinic acid (21-hydroxy-3-oxo-olean-12-en-28-oic acid) and withaferin A (4ß,27-dihydroxy-1-oxo-5ß,6ß-epoxywitha-2-24-dienolide). The structural elucidation of the isolated compounds was established using nuclear magnetic resonance (NMR) spectroscopy, mass spectroscopy (MS) and, in comparison, with the available published data. These compounds showed good antifungal activity with minimum inhibitory concentrations (MIC) less than 1.0 mg/mL against one or more of the tested Fusarium pathogens (F. oxysporum, F. verticilloides, F. subglutinans, F. proliferatum, F. solani, F. graminearum, F. chlamydosporum and F. semitectum). The findings from this study indicate that medicinal plants are a good source of natural antifungals. Furthermore, the isolated antifungal compounds did not show any phytotoxic effects on maize seed germination. The toxicity of the compounds A (5-hydroxy-7,4'-dimethoxyflavone) and AI (4ß,27-dihydroxy-1-oxo-5ß,6ß-epoxywitha-2-24-dienolide) was dose-dependent, while compound B (21-hydroxy-3-oxo-olean-12-en-28-oic acid) showed no toxicity effect against Raw 264.7 macrophage cells.


Assuntos
Antifúngicos/farmacologia , Combretum/química , Fusarium/efeitos dos fármacos , Extratos Vegetais/farmacologia , Folhas de Planta/química , Withania/química , Animais , Camundongos , Testes de Sensibilidade Microbiana , Células RAW 264.7
18.
J Med Microbiol ; 70(8)2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34431765

RESUMO

Introduction. Resistance rates to azoles and echinocandins of Candida spp. increased over the last decade.Hypothesis/Gap Statement. Widespread use of antifungals could lead to development and dissemination of resistant Candida spp.Aim. To identify risk factors for isolation of Candida spp. non-susceptible to either fluconazole or echinocandins.Methodology. All patients hospitalized in the Intensive Care Unit (ICU) of the University General Hospital of Patras, Greece with Candida spp. isolated from clinical specimens during a ten-year period (2010-19) were included. Candida isolates were identified using Vitek-2 YST card. Consumption of antifungals was calculated.Results. During the study period, 253 isolates were included. C. non-albicans predominated (64.4 %) with C. parapsilosis being the most commonly isolated (42.3 %) followed by C. glabrata (nomenclatural change to Nakaseomyces glabrataa; 8.7 %) and C. tropicalis (11.9 %). Among all isolates, 45.8 and 28.5 % were non-susceptible and resistant to fluconazole, respectively. Concerning echinocandins, 8.7 % of isolates were non-susceptible to at least one echinocandin (anidulafungin or micafungin) and 3.1 % resistant. Multivariate analysis revealed that hospitalization during 2015-19, as compared to 2010-14, isolate being non-albicans or non-susceptible to at least one echinocandin was associated with isolation of fluconazole non-susceptible isolate. Administration of echinocandin, isolate being C. glabrata or C. tropicalis, or Candida spp. non-susceptible to fluconazole were independently associated with isolation of Candida spp. non-susceptible to at least one echinocandin. Fluconazole's administration decreased during the study period, whereas liposomal-amphotericin B's and echinoncandins' administration remained stable.Conclusion. Fluconazole's non-susceptibility increased during the study period, despite the decrease of its administration. Although echinocandins' administration remained stable, non-susceptibility among Candida spp. increased.


Assuntos
Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Candidíase/microbiologia , Estado Terminal , Farmacorresistência Fúngica , Fluconazol/farmacologia , Antifúngicos/uso terapêutico , Candida/classificação , Candida/isolamento & purificação , Candidíase/diagnóstico , Candidíase/tratamento farmacológico , Candidíase/epidemiologia , Fluconazol/uso terapêutico , Grécia/epidemiologia , Humanos , Unidades de Terapia Intensiva , Testes de Sensibilidade Microbiana , Técnicas de Tipagem Micológica , Fatores de Risco
19.
Molecules ; 26(16)2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34443595

RESUMO

A newly synthetized series of N-phenacyl derivatives of 2-mercaptobenzoxazole, including analogues of 5-bromo- and 5,7-dibromobenzoxazole, were screened against Candida strains and the action mechanism was evaluated. 2-(1,3-benzoxazol-2-ylsulfanyl)-1-(4-bromophenyl)ethanone (5d), 2-(1,3-benzoxazol-2-ylsulfanyl)-1-(2,3,4-trichloro-phenyl)ethanone (5i), 2-(1,3-benzoxazol-2-ylsulfanyl)-1-(2,4,6-trichlorophenyl)ethanone (5k) and 2-[(5-bromo-1,3-benzoxazol-2-yl)sulfanyl]-1-phenylethanone (6a) showed anti-C. albicans SC5314 activity, where 5d displayed MICT = 16 µg/mL (%R = 100) and a weak anti-proliferative activity against the clinical strains: C. albicans resistant to azoles (Itr and Flu) and C. glabrata. Derivatives 5k and 6a displayed MICP = 16 µg/mL and %R = 64.2 ± 10.6, %R = 88.0 ± 9.7, respectively, against the C. albicans isolate. Derivative 5i was the most active against C. glabrata (%R = 53.0 ± 3.5 at 16 µg/mL). Benzoxazoles displayed no MIC against C. glabrata. Benzoxazoles showed a pleiotropic action mode: (1) the total sterols content was perturbed; (2) 2-(1,3-benzoxazol-2-ylsulfanyl)-1-(3,4-dichlorophenyl)ethanol and 2-(1,3-benzoxazol-2-ylsulfanyl)-1-(2,3,4-trichlorophenyl)ethanol (8h-i) at the lowest fungistatic conc. inhibited the efflux of the Rho123 tracker during the membrane transport process; (3) mitochondrial respiration was affected/inhibited by the benzoxazoles: 2-(1,3-benzoxazol-2-ylsulfanyl)-1-(4-chlorophenyl)ethanol and 2-(1,3-benzoxazol-2-ylsulfanyl)-1-(4-bromophenyl)ethanol 8c-d and 8i. Benzoxazoles showed comparable activity to commercially available azoles due to (1) the interaction with exogenous ergosterol, (2) endogenous ergosterol synthesis blocking as well as (3) membrane permeabilizing properties typical of AmB. Benzoxazoles display a broad spectrum of anti-Candida activity and action mode towards the membrane without cross-resistance with AmB; furthermore, they are safe to mammals.


Assuntos
Antifúngicos/química , Antifúngicos/farmacologia , Benzoxazóis/química , Benzoxazóis/farmacologia , Candida/efeitos dos fármacos , Testes de Sensibilidade Microbiana
20.
Front Cell Infect Microbiol ; 11: 698662, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34368017

RESUMO

Scedosporium and Lomentospora species are filamentous fungi responsible for a wide range of infections in humans and are frequently associated with cystic fibrosis and immunocompromising conditions. Because they are usually resistant to many antifungal drugs available in clinical settings, studies of alternative targets in fungal cells and therapeutic approaches are necessary. In the present work, we evaluated the in vitro antifungal activity of miltefosine against Scedosporium and Lomentospora species and how this phospholipid analogue affects the fungal cell. Miltefosine inhibited different Scedosporium and Lomentospora species at 2-4 µg/ml and reduced biofilm formation. The loss of membrane integrity in Scedosporium aurantiacum caused by miltefosine was demonstrated by leakage of intracellular components and lipid raft disorganisation. The exogenous addition of glucosylceramide decreased the inhibitory activity of miltefosine. Reactive oxygen species production and mitochondrial activity were also affected by miltefosine, as well as the susceptibility to fluconazole, caspofungin and myoricin. The data obtained in the present study contribute to clarify the dynamics of the interaction between miltefosine and Scedosporium and Lomentospora cells, highlighting its potential use as new antifungal drug in the future.


Assuntos
Ascomicetos , Scedosporium , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Humanos , Testes de Sensibilidade Microbiana , Fosforilcolina/análogos & derivados
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