Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 5.932
Filtrar
1.
Klin Lab Diagn ; 64(11): 690-692, 2019.
Artigo em Russo | MEDLINE | ID: mdl-31747500

RESUMO

When studying the effect of the metabolic products of clinical isolates of enterococci on the viability of Candida albicans, it was found that metabolites of all tested strains of Enterococcus faecium, E. faecalis had a fungistatic effect. At the same time a reliable fungicidal effect is a strain-specific feature. It is better to use the method of delayed antagonism on double-layer agar to assess the antifungal effect of enterococcal metabolism products.


Assuntos
Antifúngicos/química , Candida/efeitos dos fármacos , Enterococcus faecalis/química , Enterococcus faecium/química , Testes de Sensibilidade Microbiana
2.
J Assoc Physicians India ; 67(9): 42-45, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31561688

RESUMO

Introduction: The incidence of the urinary tract infections caused by Candida species, are becoming more common. Recently, an increase in the incidence of infection caused by fungi especially non albicans candida species (NAC) has been reported. Several virulence factors like biofilm formation, toxin production and presence of adhesins contribute to its pathogenesis. Objectives: This study was undertaken to determine species distribution, biofilm formation and in-vitro antifungal susceptibility of candida isolated in our tertiary care hospital. Method: Eighty seven clinical isolates obtained from urine specimens were subjected to wet mount, Gram's stain and cultured on Sabouraud's Dextrose agar (SDA) medium. Conventional method for yeast identification was done. Biofilm forming ability of each isolate was detected using microtitre plate method. Antifungal susceptibility against posaconazole, amphotericin-B, fluconazole, itraconazole, ketoconazole, 5-flucytosine, voriconazole, and caspofungin was tested using Sensititre® Yeastone® (Trek diagnostic systems). Results and Discussion: Out of 87 candida isolates, 31.03% (n=27) were C. albicans and 68.97% (n=60) were non albicans candida species (NAC). Among 60 NAC, C. kruseii 29.89% (n=26), C. glabrata 24.14% (n=21), C. tropicalis 14.94% (n=13). Among all isolates, 36.78% (n=32) were biofilm producers and biofilm positivity more among C. albicans 55.56% (n=15) as compared to NAC 28.33% (n=17) (Pvalue<0.002). The maximum positivity was observed with isolates from plastic devices (61.8%). The minimum inhibitory concentrations of all antifungal drugs against all isolates were within susceptible range except for fluconazole which was resistant to C. kruseii. Conclusion: C. albicans remains the major isolate from urine samples and also biofilm formation as a virulence factor might have a higher significance for C. albicans than for NAC and its ability to form biofilm is intricately linked with ability of organisms to adhere, colonize and subsequently cause infection.


Assuntos
Antifúngicos/uso terapêutico , Biofilmes/crescimento & desenvolvimento , Candida/efeitos dos fármacos , Infecções Urinárias/tratamento farmacológico , Antifúngicos/farmacologia , Candida/isolamento & purificação , Humanos , Testes de Sensibilidade Microbiana , Centros de Atenção Terciária , Infecções Urinárias/microbiologia
4.
J Nanobiotechnology ; 17(1): 81, 2019 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-31286976

RESUMO

BACKGROUND: Magnetic nanoparticles (MNPs) are characterized by unique physicochemical and biological properties that allow their employment as highly biocompatible drug carriers. Gelsolin (GSN) is a multifunctional actin-binding protein involved in cytoskeleton remodeling and free circulating actin sequestering. It was reported that a gelsolin derived phosphoinositide binding domain GSN 160-169, (PBP10 peptide) coupled with rhodamine B, exerts strong bactericidal activity. RESULTS: In this study, we synthesized a new antibacterial and antifungal nanosystem composed of MNPs and a PBP10 peptide attached to the surface. The physicochemical properties of these nanosystems were analyzed by spectroscopy, calorimetry, electron microscopy, and X-ray studies. Using luminescence based techniques and a standard killing assay against representative strains of Gram-positive (Staphylococcus aureus MRSA Xen 30) and Gram-negative (Pseudomonas aeruginosa Xen 5) bacteria and against fungal cells (Candida spp.) we demonstrated that magnetic nanoparticles significantly enhance the effect of PBP10 peptides through a membrane-based mode of action, involving attachment and interaction with cell wall components, disruption of microbial membrane and increased uptake of peptide. Our results also indicate that treatment of both planktonic and biofilm forms of pathogens by PBP10-based nanosystems is more effective than therapy with either of these agents alone. CONCLUSIONS: The results show that magnetic nanoparticles enhance the antimicrobial activity of the phosphoinositide-binding domain of gelsolin, modulate its mode of action and strengthen the idea of its employment for developing the new treatment methods of infections.


Assuntos
Antibacterianos/química , Antifúngicos/química , Gelsolina/química , Nanopartículas de Magnetita/química , Fragmentos de Peptídeos/química , Biofilmes , Candida/efeitos dos fármacos , Membrana Celular/metabolismo , Ouro/química , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Nanoconchas/química , Plâncton , Pseudomonas aeruginosa/efeitos dos fármacos , Rodaminas/química
5.
Chem Biodivers ; 16(8): e1900204, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31298500

RESUMO

The purpose of this work was to determine the chemical composition and evaluate the antichemotactic, antioxidant, and antifungal activities of the essential oil obtained from the species Cryptocarya aschersoniana Mez, Cinnamomum amoenum (Ness & Mart.) Kosterm., and Schinus terebinthifolia Raddi, as well as the combination of C. aschersoniana essential oil and terbinafine against isolates of dermatophytes. Allo-aromadendrene, bicyclogermacrene, and germacrene B were identified as major compounds in essential oils. The essential oil of C. aschersoniana shown 100 % inhibitory effect on leukocyte migration at the concentration of 10 µg/mL while S. terebinthifolia oil presented 80.1 % inhibitory effect at the same concentration. Only S. terebinthifolia oil possessed free-radical-scavenging activity which indicates its antioxidant capacity. The essential oils were also tested against fungal isolates of dermatophyte species (Trichophyton rubrum, Trichophyton mentagrophytes, Microsporum canis and Microsporum gypseum), resulting in MIC ranging from 125 µg/mL to over 500 µg/mL. C. aschersoniana oil combined with terbinafine resulted in an additive interaction effect. In this case, the essential oil may act as a complement to conventional therapy for the topical treatment of superficial fungal infections, mainly because it is associated with an anti-inflammatory effect.


Assuntos
Anacardiaceae/química , Antifúngicos/química , Cinnamomum/química , Cryptocarya/química , Óleos Voláteis/química , Anacardiaceae/metabolismo , Antifúngicos/farmacologia , Antioxidantes/química , Candida/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Cinnamomum/metabolismo , Cryptocarya/metabolismo , Testes de Sensibilidade Microbiana , Microsporum/efeitos dos fármacos , Neutrófilos/citologia , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Óleos Voláteis/farmacologia , Extratos Vegetais/química , Trichophyton/efeitos dos fármacos
6.
Eur J Med Chem ; 179: 634-648, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31279296

RESUMO

Systemic candidiasis is a rampant bloodstream infection of Candida spp. and C. albicans is the major pathogen isolated from infected humans. Azoles, the most common class of antifungals which suffer from increasing resistance, and especially intrinsically resistant non-albicans Candida (NAC) species, act by inhibiting fungal lanosterol 14α-demethylase (CYP51). In this study we identified a number of azole compounds in 1-(2,4-dichlorophenyl)-2-(1H-imidazol-1-yl)ethanol/ethanone oxime ester structure through virtual screening using consensus scoring approach, synthesized and tested them for their antifungal properties. We reached several hits with potent activity against azole-susceptible and azole-resistant Candida spp. as well as biofilms of C. albicans. 5i's minimum inhibitor concentration (MIC) was 0.125 µg/ml against C. albicans, 0.5 µg/ml against C. krusei and 1 µg/ml against azole-resistant C. tropicalis isolate. Considering the MIC values of fluconazole against these fungi (0.5, 32 and 512 µg/ml, respectively), 5i emerged as a highly potent derivative. The minimum biofilm inhibitor concentration (MBIC) of 5c, 5j, and 5p were 0.5 µg/ml (and 5i was 2 µg/ml) against C. albicans biofilms, lower than that of amphotericin B (4 µg/ml), a first-line antifungal with antibiofilm activity. In addition, the active compounds showed neglectable toxicity to human monocytic cell line. We further analyzed the docking poses of the active compounds in C. albicans CYP51 (CACYP51) homology model catalytic site and identified molecular interactions in agreement with those of known azoles with fungal CYP51s and mutagenesis studies of CACYP51. We observed the stability of CACYP51 in complex with 5i in molecular dynamics simulations.


Assuntos
Antifúngicos/farmacologia , Azóis/farmacologia , Biofilmes/efeitos dos fármacos , Candida/efeitos dos fármacos , Descoberta de Drogas , Antifúngicos/química , Azóis/química , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Humanos , Testes de Sensibilidade Microbiana , Modelos Moleculares , Estrutura Molecular , Relação Estrutura-Atividade
7.
Eur J Med Chem ; 179: 779-790, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31288127

RESUMO

Azole antifungals inhibit the biosynthesis of ergosterol, the fungal equivalent of cholesterol in mammalian cells. Here we report an investigation of the activity of coumarin-substituted azole antifungals. Screening against a panel of Candida pathogens, including a mutant lacking CYP51, the target of antifungal azoles, revealed that this enzyme is inhibited by triazole-based antifungals, whereas imidazole-based derivatives have more than one mode of action. The imidazole-bearing antifungals more effectively reduced trailing growth associated with persistence and/or recurrence of fungal infections than triazole-based derivatives. The imidazole derivatives were more toxic to mammalian cells and more potently inhibited the activity of CYP3A4, which is one of the main causes of azole toxicity. Using live cell imaging, we showed that regardless of the type of azole ring fluorescent 7-diethylaminocoumarin-based azoles localized to the endoplasmic reticulum, the organelle that harbors CYP51. This study suggests that the coumarin is a promising scaffold for development of novel azole-based antifungals that effectively localize to the fungal cell endoplasmic reticulum.


Assuntos
Antifúngicos/farmacologia , Azóis/farmacologia , Candida/efeitos dos fármacos , Cumarínicos/farmacologia , Antifúngicos/síntese química , Antifúngicos/química , Azóis/síntese química , Azóis/química , Candida/citologia , Sobrevivência Celular/efeitos dos fármacos , Cumarínicos/química , Relação Dose-Resposta a Droga , Células HEK293 , Células Hep G2 , Humanos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Imagem Óptica , Relação Estrutura-Atividade
8.
Int J Nanomedicine ; 14: 4667-4679, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31308652

RESUMO

Purpose: The pathogenicity in Candida spp was attributed by several virulence factors such as production of tissue damaging extracellular enzymes, germ tube formation, hyphal morphogenesis and establishment of drug resistant biofilm. The objective of present study was to investigate the effects of silver nanoparticles (AgNPs) on growth, cell morphology and key virulence attributes of Candida species. Methods: AgNPs were synthesized by the using seed extract of Syzygium cumini (Sc), and were characterized by UV-Vis spectrophotometer, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), and transmission electron microscopy (TEM). ScAgNPs were used to evaluate their antifungal and antibacterial activity as well as their potent inhibitory effects on germ tube and biofilm formation and extracellular enzymes viz. phospholipases, proteinases, lipases and hemolysin secreted by Candida spp. Results: The MICs values of ScAgNPs were ranged from 0.125-0.250 mg/ml, whereas the MBCs and MFCs were 0.250 and 0.500 mg/ml, respectively. ScAgNPs significantly inhibit the production of phospholipases by 82.2, 75.7, 78.7, 62.5, and 65.8%; proteinases by 82.0, 72.0, 77.5, 67.0, and 83.7%; lipase by 69.4, 58.8, 60.0, 42.9, and 65.0%; and hemolysin by 62.8, 69.7, 67.2, 73.1, and 70.2% in C. albicans, C. tropicalis, C. dubliniensis, C. parapsilosis and C. krusei, respectively, at 500 µg/ml. ScAgNPs inhibit germ tube formation in C. albicans up to 97.1% at 0.25 mg/ml. LIVE/DEAD staining results showed that ScAgNPs almost completely inhibit biofilm formation in C. albicans. TEM analysis shows that ScAgNPs not only anchored onto the cell surface but also penetrated and accumulated in the cytoplasm that causes severe damage to the cell wall and cytoplasmic membrane. Conclusion: To summarize, the biosynthesized ScAgNPs strongly suppressed the multiplication, germ tube and biofilm formation and most importantly secretion of hydrolytic enzymes (viz. phospholipases, proteinases, lipases and hemolysin) by Candia spp. The present research work open several avenues of further study, such as to explore the molecular mechanism of inhibition of germ tubes and biofilm formation and suppression of production of various hydrolytic enzymes by Candida spp.


Assuntos
Antifúngicos/farmacologia , Candida/crescimento & desenvolvimento , Candida/patogenicidade , Nanopartículas Metálicas/química , Prata/farmacologia , Antifúngicos/química , Biofilmes/efeitos dos fármacos , Candida/citologia , Candida/efeitos dos fármacos , Parede Celular/efeitos dos fármacos , Proteínas Hemolisinas/metabolismo , Humanos , Hidrólise , Nanopartículas Metálicas/ultraestrutura , Testes de Sensibilidade Microbiana , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Syzygium/química , Virulência/efeitos dos fármacos , Fatores de Virulência
9.
J Photochem Photobiol B ; 197: 111556, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31326842

RESUMO

Facile green synthesis of copper nanoparticles from different biological procedures has been indicated, but among all, biosynthesis of copper nanoparticles from medicinal plants is considered as the most suitable method. The use of medicinal plant material increases the therapeutical effects of copper nanoparticles. The aim of this study was green synthesis of copper nanoparticles from aqueous extract of Falcaria vulgaris leaf (CuNPs) and assessment of their cytotoxicity, antioxidant, antifungal, antibacterial, and cutaneous wound healing properties. These nanoparticles were characterized by X-ray diffraction (XRD), fourier-transform infrared spectroscopy (FT-IR), ultraviolet-visible spectroscopy (UV), transmission electron microscopy (TEM), and field emission scanning electron microscopy (FE-SEM) analysis. The synthesized CuNPs had great cell viability dose-dependently (Investigating the effect of the CuNPs on human umbilical vein endothelial cell (HUVEC) line) and indicated this method was nontoxic. Also, 2,2-diphenyl-1-picrylhydrazyl (DPPH) test was done to assess the antioxidant activities, which indicated similar antioxidant potentials for CuNPs and butylated hydroxytoluene. In part of cutaneous wound healing property of CuNPs, after creating the cutaneous wound, the rats were randomly divided into six groups: treatment with 0.2% CuNPs ointment, treatment with 0.2% CuSO4 ointment, treatment with 0.2% F. vulgaris ointment, treatment with 3% tetracycline ointment, treatment with Eucerin basal ointment, and untreated control. These groups were treated for 10 days. Treatment with CuNPs ointment remarkably increased (p ≤ .01) the wound contracture, vessel, hexosamine, hydroxyl proline, hexuronic acid, fibrocyte, and fibrocytes/fibroblast rate and substantially reduced (p ≤ .01) the wound area, total cells, neutrophil, and lymphocyte compared to other groups. In antibacterial and antifungal parts of this research, the concentration of CuNPs with minimum dilution and no turbidity was considered minimum inhibitory concentration (MIC). To determine minimum fungicidal concentration (MFC) and minimum bactericidal concentration (MBC), 60 µL MIC and three preceding chambers were cultured on Sabouraud Dextrose Agar and Muller Hinton Agar, respectively. The minimum concentration with no fungal and bacterial growth were considered MFC and MBC, respectively. CuNPs inhibited the growth of all fungi at 2-4 mg/mL concentrations and removed them at 4-8 mg/mL concentrations (p ≤ .01). In case of antibacterial effects of CuNPs, they inhibited the growth of all bacteria at 2-8 mg/mL concentrations and removed them at 4-16 mg/mL concentrations (p ≤ .01). The results of XRD, FT-IR, UV, TEM, and FE-SEM confirm that the aqueous extract of F. vulgaris leaf can be used to yield copper nanoparticles with notable amount of antioxidant, antifungal, antibacterial, and cutaneous wound healing potentials without any cytotoxicity. Further clinical trials are necessary for confirmation these therapeutical effects of CuNPs in human.


Assuntos
Apiaceae/química , Cobre/química , Nanopartículas Metálicas/química , Extratos Vegetais/química , Animais , Antibacterianos/síntese química , Antibacterianos/química , Antibacterianos/farmacologia , Antifúngicos/síntese química , Antifúngicos/química , Antifúngicos/farmacologia , Antioxidantes/química , Apiaceae/metabolismo , Candida/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Química Verde , Células Endoteliais da Veia Umbilical Humana , Humanos , Masculino , Nanopartículas Metálicas/toxicidade , Testes de Sensibilidade Microbiana , Folhas de Planta/química , Folhas de Planta/metabolismo , Ratos , Pele/efeitos dos fármacos , Pele/patologia , Cicatrização/efeitos dos fármacos
10.
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
11.
J Med Microbiol ; 68(9): 1353-1358, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31271350

RESUMO

Introduction. Candida auris is a pathogenic yeast that mainly affects immunosuppressed patients and those with implanted medical devices. This pathogen also displays elevated resistance to common antifungals and high survival and spreading capacities. Since no antifungal breakpoints have yet been defined for this pathogen, the data obtained here can be useful for further research concerning treatment or implementation of a prevention and disinfection protocol. Our aim was to study the antifungal resistance of C. auris to current antifungals in planktonic and sessile states. Using confocal laser scanning microscopy and viable biomass production, we demonstrated the ability of C. auris to develop a mature biofilm. We compared the minimal inhibitory concentration (MIC) and the minimal biofilm eradication concentration (MBEC) for the C. auris DSM 21092 strain plus two clinical isolates, and the results were compared with those obtained for Candida albicans and Candida parapsilosis, two species strongly linked to bloodstream infections and infections associated with biomaterials. We found that the clinical isolates of C. auris were resistant to fluconazole and sensitive to echinocandins and polyenes. The C. auris biofilms did not show susceptibility to any antifungal agent, showing MBECs that were up to 512-fold higher than the MICs. These findings highlight the importance of biofilm formation as a key factor underlying the resistance of this species to antifungals and suggest that the presence of implantable medical devices is one of the major risk factors in immunocompromised patients.


Assuntos
Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Candida/efeitos dos fármacos , Candida/isolamento & purificação , Candida albicans/efeitos dos fármacos , Candida parapsilosis/efeitos dos fármacos , Candidíase/microbiologia , Contagem de Colônia Microbiana , Farmacorresistência Fúngica , Equinocandinas/farmacologia , Fluconazol/farmacologia , Humanos , Testes de Sensibilidade Microbiana , Microscopia Confocal , Polienos/farmacologia
12.
Int J Infect Dis ; 86: 142-146, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31330325

RESUMO

OBJECTIVE: To describe the pharmacokinetic (PK) profile of anidulafungin and to evaluate its concentration in the peritoneal fluid (PF) of patients suspected of suffering from peritoneal infection undergoing abdominal surgery, in order to ensure that therapeutic levels are achieved within the peritoneal cavity. METHODS: A descriptive, open, prospective, observational, multicentre and non-interventional study was performed. Anidulafungin was used at conventional doses. Blood and PF samples were obtained on day 2 of treatment or on any of the following days. RESULTS: A total of 31 patients in a serious clinical condition, as demonstrated by high mean clinical severity scale scores (APACHE II and SOFA scores), were included in the study. The mean area under the curve (AUC) in PF was 30% (31±19%) of that determined in the plasma and the maximum concentration (Cmax) reached in PF (mg/l) was close to 1 (0.9±0.5). No adverse effects were observed in any of the 31 patients. CONCLUSIONS: Anidulafungin at conventional doses reaches PF concentrations that exceed the minimum inhibitory concentration of the usual Candida spp, which explains the proven efficacy of this echinocandin in the treatment of Candida peritonitis in critically ill patients.


Assuntos
Anidulafungina/farmacocinética , Antifúngicos/farmacocinética , Candidíase/tratamento farmacológico , Estado Terminal , Peritonite/tratamento farmacológico , APACHE , Idoso , Idoso de 80 Anos ou mais , Anidulafungina/uso terapêutico , Antifúngicos/uso terapêutico , Área Sob a Curva , Líquido Ascítico/metabolismo , Candida/efeitos dos fármacos , Equinocandinas/uso terapêutico , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Peritonite/microbiologia , Estudos Prospectivos
15.
Int J Food Microbiol ; 304: 75-88, 2019 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-31174038

RESUMO

Fermented cereal doughs constitute a predominant part of West African diets. The environment of fermented doughs can be hostile for microbial survival due to high levels of microbial metabolites such as weak carboxylic organic acids and ethanol. In order to get a better understanding of the intrinsic factors affecting the microbial successions of yeasts during dough fermentation, survival and physiological responses of the yeasts associated with West African fermented cereal doughs were investigated at exposure to relevant concentrations of microbial inhibitory compounds. Three strains each of the predominant species, i.e. Saccharomyces cerevisiae, Kluyveromyces marxianus, Pichia kudriavzevii as well as the opportunistic pathogen Candida glabrata were studied. The strains were exposed to individual stress factors of cereal doughs, i.e. (i) pH 3.4, (ii) 3% (v/v) ethanol (EtOHpH3.4), (iii) 285 mM lactic acid (LApH3.4) and (iv) 150 mM acetic acid (AApH3.4) as well as to combinations of these stress factors, i.e. (v) (LA + AA)pH 3.4 and (vi) (LA + AA+EtOH)pH 3.4. Growth and single cell viability were studied by flow cytometry using combined SYTO 13 and propidium iodide (PI) staining. Intracellular pH (pHi), plasma membrane integrity and micro-colony development of stressed cells were studied by fluorescence microscopy using PI and carboxyfluorescein diacetate succinimidyl ester (CFDA-se). Viability of the yeast strains was not affected by pH 3.4 and 3% (v/v) ethanol (EtOHpH3.4). 285 mM lactic acid (LApH3.4) reduced the specific growth rate (µmax) from 0.27-0.41 h-1 to 0.11-0.26 h-1 and the viability from 100% to 2.6-41.7% at 72 h of exposure in most yeast strains, except for two strains of C. glabrata. 150 mM acetic acid (AApH3.4) as well as the combinations (LA + AA)pH 3.4 and (LA + AA+EtOH)pH 3.4 reduced µmax to 0.0 h-1 and induced significant cell death for all the yeast strains. Exposed to (LA + AA+EtOH)pH 3.4, the most resistant yeast strains belonged to S. cerevisiae followed by P. kudriavzevii, whereas C. glabrata and K. marxianus were more sensitive. Strain variations were observed within all four species. When transferred to non-stress conditions, i.e. MYGP, pH 5.6, after exposure to (LA + AA+EtOH)pH 3.4 for 6 h, 45% of the single cells of the most resistant S. cerevisiae strain kept their plasma membrane integrity, recovered their pHi to near physiological range (pHi = 6.1-7.4) and resumed proliferation after 3-24 h of lag phase. The results obtained are valuable in order to change processing conditions of the dough to favor the survival of preferable yeast species, i.e. S. cerevisiae and K. marxianus and inhibit opportunistic pathogen yeast species as C. glabrata.


Assuntos
Candida/efeitos dos fármacos , Grão Comestível/microbiologia , Alimentos Fermentados/microbiologia , Kluyveromyces/efeitos dos fármacos , Viabilidade Microbiana/efeitos dos fármacos , Pichia/efeitos dos fármacos , Saccharomyces cerevisiae/efeitos dos fármacos , Ácido Acético/farmacologia , Reatores Biológicos , Candida/crescimento & desenvolvimento , Candida/isolamento & purificação , Etanol/farmacologia , Fermentação , Kluyveromyces/crescimento & desenvolvimento , Kluyveromyces/isolamento & purificação , Ácido Láctico/farmacologia , Pichia/crescimento & desenvolvimento , Pichia/isolamento & purificação , Saccharomyces cerevisiae/crescimento & desenvolvimento , Saccharomyces cerevisiae/isolamento & purificação , Fermento Seco , Leveduras/isolamento & purificação
17.
Chem Biodivers ; 16(8): e1900131, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31173470

RESUMO

Most species of the genus Laggera are often used in traditional and folk medicines for the treatment of jaundice, inflammation, leukemia, removing phlegm, bronchitis and bacterial diseases. The essential oils obtained from Laggera plants are rich sources of oxygenated monoterpenes and sesquiterpenes. Among oxygenated monoterpenes, aromatic ether 2,5-dimethoxy-p-cymene is the most abundant and dominant compound of many essential oils of the Laggera species. Till today, to the best of our knowledge, chemical compounds of the essential oils and/or extracts of only eight Laggera species were reported from different countries. Thus, this review presents the chemical compositions and biological activities of the essential oils of these plants studied in thirteen countries. In addition, it discusses the reported ethnobotanical and ethnopharmacological information as well as biological activities of the extracts and some of the isolated compounds of Laggera plants species.


Assuntos
Asteraceae/metabolismo , Óleos Voláteis/química , Antioxidantes/química , Candida/efeitos dos fármacos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Medicina Tradicional , Óleos Voláteis/farmacologia , Fenóis/química , Extratos Vegetais/química , Compostos Orgânicos Voláteis/química
18.
Plant Dis ; 103(9): 2231-2236, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31241409

RESUMO

Monilia mumecola is one of the causal agents of peach brown rot in China. In this study, M. mumecola isolates from different locations and hosts were used to analyze the genetic diversity and to assay the sensitivity to four generally used fungicides: carbendazim, tebuconazole, azoxystrobin, and boscalid. Results showed that isolates from different locations tended to be separated. Interestingly, isolates from different hosts (e.g., peach and apricot) at the same locations generally clustered together, indicating that the M. mumecola isolates may infect different hosts in the same areas. The fungicide sensitivity assay of 93 M. mumecola isolates showed that the average effective concentration for 50% mycelial growth inhibition values for carbendazim, tebuconazole, azoxystrobin, and boscalid were 0.103, 0.034, 0.325, and 0.419 µg/ml, respectively. The sensitivity distributions of the tested isolates to the four fungicides showed continuous unimodal curves, indicating no qualitative shift of resistance. No significant difference of sensitivity to tested fungicides was observed among isolates from either different locations or different hosts.


Assuntos
Candida , Fungicidas Industriais , Filogenia , Candida/classificação , Candida/efeitos dos fármacos , China , Fungicidas Industriais/farmacologia , Variação Genética , Testes de Sensibilidade Microbiana , Prunus armeniaca/microbiologia , Prunus persica/microbiologia
19.
Microb Pathog ; 135: 103608, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31229603

RESUMO

This study aimed to determinate the chemical composition and evaluate the antimicrobial and antioxidant activity of the essential oil obtained from leaves of V. gardneriana. The Vitex gardneriana leaves's were hydrodistilled to obtain the essential oil and the chemical composition determined by GC/MS analysis. The antimicrobial activities were determined by microdilution method. The activity of essential oil on biofilm was evaluated by quantification of total biomass and enumeration of biofilm-entrapped viable cells. The antioxidant activity was assessed by DPPH free radical assay, ferrous ion chelating assay, ferric-reducing antioxidant power and ß-carotene bleaching assay. Furthermore, the essential oil was tested on viability of health human, animal cells and the microcrustacean Artemia sp. The essential oil showed high content of sesquiterpenes and very low content of monoterpenes. Regarding activity on planktonic cells, the essential oil reduced the growth of the all species tested but showed MIC values only to S. aureus (0.31%). In general, the essential oil reduced significantly the biofilm biomass and the number of viable cells of bacteria and yeasts, mainly on biofilm formation. The essential oil showed a potential antioxidant activity, mainly on ß-carotene oxidation. Moreover, the essential oil reduced the cell viability of murine fibroblasts but not show viability reduction of human keratinocytes. Furthermore, the oil not show toxicity against the microcrustacean. Thus, the essential oil from V. gardneriana leaves may be considered as an important alternative against biofilms formed by bacteria and yeasts related to infections, as well as a natural antioxidant and non-toxic substance on human cells.


Assuntos
Anti-Infecciosos/química , Antioxidantes/química , Óleos Voláteis/química , Extratos Vegetais/química , Folhas de Planta/química , Vitex/química , Animais , Anti-Infecciosos/farmacologia , Artemia/efeitos dos fármacos , Bactérias/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Brasil , Candida/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Camundongos , Testes de Sensibilidade Microbiana , Monoterpenos/química , Óleos Voláteis/isolamento & purificação , Óleos Voláteis/farmacologia , Extratos Vegetais/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , beta Caroteno
20.
Eur J Med Chem ; 178: 515-529, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31207463

RESUMO

Carvacrol (CAR), a natural monoterpene particularly abundant in plants belonging to the Lamiaceae family, has recently attracted much attention for its many biological properties (antioxidant, anti-inflammatory, neuroprotective, antitumour, antibacterial, and several others). However, CAR has poor chemical-physical properties (low water solubility and high volatility), which hamper its potential pharmacological uses. In this paper, the synthesis and antimicrobial evaluation of 23 carvacrol derivatives (WSCP1-23) against a panel of selected gram-positive and gram-negative bacteria are reported. Using the prodrug approach, CAR hydrophilic (WSCP1-17) and lipophilic prodrugs (WSCP18-23) were prepared. Notably, CAR water solubility was increased by using polar neutral groups (such as natural amino acids) with the aim of improving oral drug delivery. On the other hand, CAR lipophilic prodrugs, obtained by prenylation of CAR hydroxyl group, were designed to promote membrane permeation and oral absorption. Our results revealed that WSCP1-3, showing the highest water solubility (>1700-fold compared to that of CAR), possessed good antibacterial activity against gram-negative bacteria with MIC values comparable to those of CAR and antifungal properties against different species of Candida. WSCP18-19 were the most promising prodrugs, showing good antibacterial profiles against gram-positive bacteria by interfering with the biofilm formation of Staphylococcus aureus and Staphylococcus epidermidis. Moreover, WSCP18-19 resulted more stable in simulated fluids and human plasma than WSCP1-3. Toxicity studies performed on human erythrocytes and HaCaT cells revealed that all WSCPs were not toxic at the tested concentrations.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Monoterpenos/farmacologia , Pró-Fármacos/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Antifúngicos/síntese química , Antifúngicos/química , Candida/efeitos dos fármacos , Relação Dose-Resposta a Droga , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Monoterpenos/síntese química , Monoterpenos/química , Pró-Fármacos/síntese química , Pró-Fármacos/química , Solubilidade , Relação Estrutura-Atividade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA