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1.
BMC Microbiol ; 20(1): 95, 2020 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-32295517

RESUMO

BACKGROUND: The microbiome of Severe-Early Childhood Caries (S-ECC), is characterized by an ecosystem comprising bacterial and fungal species, with a predominance of Candida species. Hence, an anti-cariogen effective against both bacteria and fungi would be valuable in the management of S-ECC. Here we evaluate the antifungal effect of silver diamine fluoride (SDF) against 35-clinical yeast isolates (Ten-each of C. albicans, C. krusei, C. tropicalis and five C. glabrata strains) from dentinal caries-lesions from S-ECC. RESULTS: Disc-diffusion and time-kill assays as well as MIC50 and MIC90 evaluations against therapeutic concentrations confirmed the broad-spectrum anti-candidal potency of SDF. Ultrastructural images revealed morphologic aberrations of yeast-cell walls on exposure to SDF. All C. krusei and C. glabrata isolates were significantly more sensitive to SDF, relative to the standard antifungal fluconazole. Further, SDF appears to effectively abrogate filamentation of C. albicans even at very low concentrations. CONCLUSIONS: Our data, for the first time, elucidate the antifungal potency of SDF, in addition to its known antibacterial activity, in the management of S-ECC.


Assuntos
Antifúngicos/farmacologia , Candida/crescimento & desenvolvimento , Cárie Dentária/prevenção & controle , Compostos de Amônio Quaternário/farmacologia , Compostos de Prata/farmacologia , Biofilmes/efeitos dos fármacos , Candida/classificação , Candida/efeitos dos fármacos , Candida/ultraestrutura , Parede Celular/efeitos dos fármacos , Parede Celular/ultraestrutura , Criança , Farmacorresistência Fúngica/efeitos dos fármacos , Fluoretos Tópicos/farmacologia , Humanos , Testes de Sensibilidade Microbiana
2.
Lett Appl Microbiol ; 71(4): 413-419, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32623751

RESUMO

As a result of electron microscopic studies of morphogenesis in yeast Candida guilliermondii NP-4, the formation of new structures of volutin acidocalcisomes has been established within the cell cytoplasm. Under influence of X-irradiation, the changes in morphometric and electron-dense properties of yeast cells were identified: in yeast cytoplasm, the electron-dense volutin granules were increased up to 400 nm in size. After 24-h post-irradiation incubation of yeasts, the large volutin pellets are fragmented into smaller number particles in size up to 25-150 nm. The ATPase activity in yeast mitochondria was changed under X-irradiation. In latent phase of growth, ATPase activity was decreased 1·35-fold in comparison with non-irradiated yeasts. In logarithmic phase of growth, ATPase activity was three times higher than in latent phase, and in stationary phase of growth it has a value similar to the latent phase. Probably, the cells receive the necessary energy from alternative energy sources, such as volutin. Electron microscopy of volutin granule changes might serve as convenient method for evaluation of damages and repair processes in cells under influence of different environmental stress-factors.


Assuntos
Adenosina Trifosfatases/metabolismo , Candida/efeitos da radiação , Candida/ultraestrutura , Proteínas Fúngicas/metabolismo , Organelas/enzimologia , Adenosina Trifosfatases/genética , Adenosina Trifosfatases/ultraestrutura , Trifosfato de Adenosina/metabolismo , Candida/enzimologia , Candida/genética , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Organelas/genética , Organelas/efeitos da radiação , Organelas/ultraestrutura , Raios X
3.
Mycopathologia ; 185(3): 415-424, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32277380

RESUMO

Fungi of the genus Candida are important etiological agents of superficial and life-threatening infections in individuals with a compromised immune system. One of the main characteristics of Candida is its ability to form highly drug tolerance biofilms in the human host. Biofilms are a dynamic community of multiple cell types whose formation over time is orchestrated by a network of transcription regulators. In this brief review, we provide an update of the processes involved in biofilm formation by Candida spp. (formation, treatment, and control), as well as the transcriptional circuitry that regulates its development and interactions with other microorganisms. Candida albicans is known to build mixed species biofilms with other Candida species and with various other bacterial species in different host niches. Taken together, these properties play a key role in Candida pathogenesis. In addition, this review gathers recent studies with new insights and perspectives for the treatment and control of Candida biofilms.


Assuntos
Biofilmes/crescimento & desenvolvimento , Candida/fisiologia , Biofilmes/efeitos dos fármacos , Candida/efeitos dos fármacos , Candida/genética , Candida/ultraestrutura , Adesão Celular/genética , Adesão Celular/fisiologia , Estudo de Associação Genômica Ampla , Humanos , Microscopia Eletrônica de Varredura , Nanotecnologia/tendências , Elementos Reguladores de Transcrição/genética , Elementos Reguladores de Transcrição/fisiologia
4.
Lasers Med Sci ; 34(7): 1457-1464, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30798389

RESUMO

This study investigated (i) the degradation effect of 405-nm blue light-emitting diode (LED) light irradiation on Candida albicans and C. glabrata biofilms formed on denture base resin and (ii) the effects of 405-nm blue LED light irradiation on the mechanical and surface characteristics of the resin. Polymethyl methacrylate denture base resin discs were prepared, and C. albicans or C. glabrata biofilms formed on the denture base resin discs. Each biofilm was irradiated with 405-nm blue LED light under a constant output power (280 mW/cm2) for different times in a moisture chamber with 100% relative humidity. Postirradiation, each biofilm was analyzed using a colony-forming unit assay, fluorescence microscopy, and scanning electron microscopy (SEM). Parallelepiped specimens of acrylic resin were prepared, and changes in their flexural strength (FS), flexural modulus (FM), and surface roughness (Ra) preirradiation and postirradiation with 405-nm blue LED light were evaluated. Irradiation for 30 min completely inhibited colony formation in both Candida species. Fluorescence microscopy showed that almost all Candida cells were killed because of irradiation. SEM images showed various cell damage patterns, such as wrinkles, shrinkage, and cell surface damage. An increase in FS was noted postirradiation, but no significant changes were observed in FM and Ra preirradiation and postirradiation. In conclusion, irradiation with 405-nm blue LED light induces degradation of C. albicans and C. glabrata biofilms on denture base resin, even in the absence of photosensitizers, without resin surface deterioration.


Assuntos
Resinas Acrílicas/farmacologia , Biofilmes/efeitos dos fármacos , Candida/efeitos dos fármacos , Bases de Dentadura , Luz , Polimetil Metacrilato/farmacologia , Candida/ultraestrutura , Candida albicans/efeitos dos fármacos , Candida albicans/ultraestrutura , Candida glabrata/efeitos dos fármacos , Candida glabrata/ultraestrutura , Contagem de Colônia Microbiana , Fármacos Fotossensibilizantes/farmacologia , Propriedades de Superfície
5.
Med Mycol ; 56(4): 493-500, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-28992253

RESUMO

The activity of fluconazole, amphotericin B, caspofungin and micafungin was determined using XTT-based fungal damage assays against planktonic cells, early and mature biofilms of Candida kefyr. Median MICs of planktonic cells were 0.25 mg/l, 0.25 mg/l, 0.5 mg/l, and 0.06 mg/l for fluconazole, amphotericin B, caspofungin, and micafungin, respectively. Fluconazole showed at least 50% fungal damage at ≥4 mg/l (51.5% ± 6.63% to 78.38% ± 1.44%) and at ≥128 mg/l (57.88% ± 9.2% to 67.25% ± 9.59%), while amphotericin B produced an even higher anti-biofilm effect at ≥0.5 mg/l (64.63% ± 6.79% to 79.5% ± 5.9%) and at ≥0.12 mg/l (77.63% ± 8.43% to 92.75% ± 1.89%) against early and mature biofilms, respectively. In case of micafungin, 50% fungal damage was observed at ≥0.06 mg/l (66.88% ± 10.16% to 98.63% ± 1.24%) and ≥0.25 mg/l (74.13% ± 10.77% to 99.38% ± 0.38%) for early and mature biofilms, respectively. Caspofungin-exposed cells showed an unexpected susceptibility pattern, that is, planktonic cells showed significantly decreased susceptibility at concentrations ranging from 0.015 mg/l to 1 mg/l compared to biofilms (P < .05-.01). The damage in planktonic cells and biofilms was comparable at higher concentrations. For planktonic cells and biofilms, 50% fungal damage was observed first at 0.5 mg/l (59.75% ± 3.16%) and at 0.06 mg/l (70.25% ± 10.95%), respectively. This unexpected pattern was confirmed using scanning electron microscopy. The unusual susceptibility pattern observed at lower caspofungin concentrations may explain the poorer outcome of caspofungin-treated C. kefyr infections documented in certain patient populations. As this phenomenon was markedly less apparent in case of micafungin, these data suggest that micafungin may be a more reliable option than caspofungin for the treatment of C. kefyr infections.


Assuntos
Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Candida/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Candida/crescimento & desenvolvimento , Candida/ultraestrutura , Candidíase Invasiva/tratamento farmacológico , Candidíase Invasiva/microbiologia , Humanos , Testes de Sensibilidade Microbiana
6.
Angew Chem Int Ed Engl ; 57(50): 16391-16395, 2018 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-30307679

RESUMO

Cationic amphiphiles are a large and diverse class of antimicrobial agents. Although their mode of action is not fully resolved, it is generally accepted that these antimicrobials perturb the structural integrity of the plasma membrane leading to the microbial cell disruption. Here we report on the development of inherently fluorescent antifungal cationic amphiphiles and on the study of their effects on cells of Candida, one of the most common fungal pathogens in humans. Fluorescent images of Candida yeast cells that express a fluorescent reporter protein revealed that the cationic amphiphiles rapidly accumulated in the cytosol and led to structural changes in proteins and DNA. Using fluorescent organelle-specific dyes, we showed that these antifungal agents also caused organelle disassembly in Candida cells. The results of this study indicate that, in designing antifungal cationic amphiphiles for clinical use, the intracellular activities of these molecules must be addressed to avoid undesired side effects to mammalian cells.


Assuntos
Antifúngicos/química , Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Tensoativos/química , Tensoativos/farmacologia , Candida/ultraestrutura , Candidíase/tratamento farmacológico , Candidíase/microbiologia , Cátions/química , Cátions/farmacologia , Humanos , Microscopia de Fluorescência , Imagem Óptica
7.
Microb Pathog ; 104: 125-132, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28089949

RESUMO

Candida infection is an important cause of morbidity and mortality on immunosuppressed patients. This growing trend has been associated with resistance to the antimicrobial therapy and the ability of microorganism to form biofilms. TTO oil is used as antimicrobial which shows antibiofilm activity against Candida species. However, it presents problems due to its poor solubility and high volatility. The present study aimed to evaluate in vitro antibiofilm activity of TTO nanoparticles against many Candida species. It was performed the characterization of the oil and nanoparticles. The levels of exopolysaccharides, proteins, and the biomass of biofilms were measured. The chromatographic profile demonstrated that the TTO oil is in accordance with ISO 4730 with major constituents of 41.9% Terpinen-4-ol, 20.1% of γ-Terpinene, 9,8% of α-Terpinene, and 6,0% of 1,8-Cineole. The TTO nanoparticles showed pH of 6.3, mean diameter of 158.2 ± 2 nm, polydispersion index of 0.213 ± 0.017, and zeta potential of -8.69 ± 0.80 mV. The addition of TTO and its nanoparticles represented a significant reduction of biofilm formed by all Candida species, as well as a reduction of proteins and exopolysaccharides levels. It was possible to visualize the reduction of biofilm in presence of TTO nanoparticles by Calcofluor White method.


Assuntos
Antifúngicos/administração & dosagem , Biofilmes/efeitos dos fármacos , Candida/efeitos dos fármacos , Candida/fisiologia , Melaleuca/química , Nanopartículas/administração & dosagem , Extratos Vegetais/administração & dosagem , Antifúngicos/química , Proteínas de Bactérias/metabolismo , Biomassa , Candida/ultraestrutura , Testes de Sensibilidade Microbiana , Nanopartículas/química , Extratos Vegetais/química , Óleos de Plantas/administração & dosagem , Óleos de Plantas/química
8.
FEMS Yeast Res ; 17(3)2017 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-28475763

RESUMO

Canals are supramolecular complexes observed in the cell wall of Candida maltosa grown in the presence of hexadecane as a sole carbon source. Such structures were not observed in glucose-grown cells. Microscopic observations of cells stained with diaminobenzidine revealed the presence of oxidative enzymes in the canals. 4΄,6΄-diamino-2-phenylindole staining revealed that a substantial part of cellular polyphosphate was present in the cell wall of cells grown on hexadecane in condition of phosphate limitation. The content and chain length of polyphosphates were higher in hexadecane-grown cells than in glucose grown ones. The treatment of cells with yeast polyphosphatase PPX1 resulted in the decrease of the canal size. These data clearly indicated that polyphosphates are constituents of canals; they might play an important role in the canal structure and functioning.


Assuntos
Alcanos/farmacologia , Candida/efeitos dos fármacos , Parede Celular/efeitos dos fármacos , 3,3'-Diaminobenzidina , Hidrolases Anidrido Ácido/química , Candida/química , Candida/metabolismo , Candida/ultraestrutura , Parede Celular/química , Parede Celular/metabolismo , Parede Celular/ultraestrutura , Meios de Cultura/química , Meios de Cultura/farmacologia , Diaminas , Glucose/metabolismo , Glucose/farmacologia , Indóis , Microscopia Eletrônica de Transmissão , Polifosfatos/química , Polifosfatos/metabolismo , Coloração e Rotulagem/métodos
9.
Med Mycol ; 55(6): 624-634, 2017 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-27915303

RESUMO

Candida species are regular commensal in humans, but-especially in immunocompromised patients-they represent opportunistic pathogens giving rise to systemic infection. The aim of the present work was to isolate and characterize for their antifungal profile Candida species from different body sites and to analyze the biofilms produced by C. albicans and C. glabrata isolates. Eighty-one strains of Candida species from 77 patients were identified. Epidemiological study showed that the most isolated species were C. albicans (44), C. glabrata (13) and C. parapsilosis (13) mainly from Hematology, Infectious Diseases, Medicine, Neonatology and Oncology Divisions, the majority of the biological samples were swabs (44) and blood cultures (16). The analysis of the biofilm formation was performed at 24 and 48-hours comparing resistant and susceptible strains of C. albicans to resistant and susceptible strains of C. glabrata. Candida albicans has a greater ability to form biofilm compared to C. glabrata, both in the susceptible and resistant strains reaching maturity after 24 hours with a complex structure composed of blastospores, pseudohyphae, and hyphae embedded in a matrix. On the contrary, C. glabrata biofilm was composed exclusively of blastospores that in the resistant strain, after 24 hours, were organized in a compact multilayer different to the discontinuous structure observed in the susceptible analyzed strains. In conclusion, the increasing of the incidence of Candida species infection together with their emerging drug resistance also related to the biofilm forming capability underline the need to monitor their distribution and susceptibility patterns for improving the surveillance and for a correct management of the infection.


Assuntos
Antifúngicos/farmacologia , Biofilmes/crescimento & desenvolvimento , Candida albicans/fisiologia , Candida glabrata/fisiologia , Candida/efeitos dos fármacos , Candida/fisiologia , Candidíase/microbiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biofilmes/efeitos dos fármacos , Candida/ultraestrutura , Candida albicans/efeitos dos fármacos , Candida albicans/ultraestrutura , Candida glabrata/efeitos dos fármacos , Candida glabrata/ultraestrutura , Farmacorresistência Fúngica , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Pessoa de Meia-Idade
10.
Mycoses ; 60(4): 260-265, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28066940

RESUMO

Vulvovaginal candidiasis (VVC) is a hormonal-dependent infection but in contrast to sporadic VVC, therapy of recurrent vulvovaginal candidiasis (RVVC) is still unsolved. Long-term administration of medroxyprogesterone acetate was evaluated for the management of RVVC. Overall, 20 patients were treated with Depo-Provera; 14 patients were treated with Provera. Gestagen therapy was evaluated based on visual analogue scale (VAS), the frequency of attacks, the side effects of gestagens and the consumption of antifungals. There was a reduced symptomatology in both of the groups and substantial reduction in antifungal drug consumption during the second year of gestagen use. Twenty-four patients (70.6%) evaluated their condition regarding the vulvovaginal area as improvement (VAS decrease of 3-5 points). Five patients (14.7%) mentioned minimal or no improvement. Further, a number of antifungal drug-treated episodes dropped dramatically during the study period. Both regimes provided similar results, but five patients from the Depo-Provera group had to withdraw from gestagen therapy. Gestagen supplementation ameliorated the quality of life for the majority of patients with RVVC and suggested a potential role in the management of this syndrome, even if beneficial effect was evident after longer application, and some patients met with side effects that led to an interruption of therapy.


Assuntos
Antifúngicos/uso terapêutico , Candidíase Vulvovaginal/tratamento farmacológico , Acetato de Medroxiprogesterona/uso terapêutico , Progestinas/uso terapêutico , Adolescente , Adulto , Candida/isolamento & purificação , Candida/ultraestrutura , Candidíase Vulvovaginal/microbiologia , Gerenciamento Clínico , Feminino , Humanos , Acetato de Medroxiprogesterona/administração & dosagem , Acetato de Medroxiprogesterona/efeitos adversos , Projetos Piloto , Progestinas/administração & dosagem , Progestinas/efeitos adversos , Estudos Prospectivos , Qualidade de Vida , Recidiva , Tempo , Escala Visual Analógica , Adulto Jovem
11.
Mycoses ; 60(3): 161-165, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27618806

RESUMO

Onychomycosis is a rare nail disorder in early childhood, while onychomadesis is a periodic idiopathic, non-inflammatory disease that affects the nail matrix and is common in children especially in those who suffer from viral infections. In this study, we investigated recent cases of onychomycosis subsequent to periods of onychomadesis in children. Sixteen young children (six males, 10 females) with a mean age of 36.5 months were diagnosed with onychomadesis, and 13 of the patients had a history of viral infection prior to nail changes. Direct microscopy of nail scaling was positive in 11 cases (68.8%), and culture was positive in the same number of cases. Four Candida species were isolated: Candida glabrata was the most frequent, found in eight cases (72.7%), while C. albicans, C. parapsilosis and C. tropicalis, each were encountered in a single case. All children were treated successfully with or without topical bifonazole therapy.


Assuntos
Candida/isolamento & purificação , Doenças da Unha/complicações , Doenças da Unha/microbiologia , Unhas/microbiologia , Onicomicose/diagnóstico , Onicomicose/etiologia , Administração Tópica , Antifúngicos/uso terapêutico , Candida/classificação , Candida/efeitos dos fármacos , Candida/ultraestrutura , Candida glabrata/efeitos dos fármacos , Candida glabrata/isolamento & purificação , Candida tropicalis/efeitos dos fármacos , Candida tropicalis/isolamento & purificação , Criança , Pré-Escolar , Feminino , Dermatoses da Mão/tratamento farmacológico , Dermatoses da Mão/microbiologia , Humanos , Imidazóis/uso terapêutico , Lactente , Masculino , Unhas/patologia , Unhas/ultraestrutura , Onicomicose/tratamento farmacológico , Onicomicose/microbiologia
12.
Vet Ophthalmol ; 20(6): 539-546, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28417524

RESUMO

OBJECTIVES: This study aimed to assess the biofilm-forming ability of Candida spp. from the ocular conjunctiva of horses and to investigate the antifungal susceptibility of these biofilms. PROCEDURES: Initially, the biofilm-forming ability of 15 strains was assessed by crystal violet staining, which reveals the fungal biomass adhered to the polystyrene plates, and scanning electron microscopy. Then, the minimum inhibitory concentrations (MICs) of amphotericin B, fluconazole, itraconazole, and caspofungin were initially determined against strains in planktonic form. Afterward, antifungal susceptibility of mature biofilms was evaluated by exposing them to 10 × MIC and 50 × MIC of the tested drugs, followed by the assessment of their metabolic activity, using the oxidoreduction indicator XTT. Results were analyzed through ANOVA and Tukey's post-test, and P-values below 5% led to significant conclusions. RESULTS: Eight strains produced biofilms and were classified as strong (1/15), moderate (3/15) and weak (4/15) producers, according to the amount of crystal violet retained by the adhered fungal biomass. Biofilm metabolic activity of one C. tropicalis did not decrease after exposure to the tested antifungals, while biofilm metabolic activity of five strains was reduced by amphotericin B, but not the other drugs. One C. parapsilosis sensu stricto and one C. glabrata showed significant reduction in biofilm metabolic activity after exposure to fluconazole, itraconazole, and caspofungin, but not amphotericin B. CONCLUSIONS: The results demonstrate that Candida from the ocular conjunctiva of horses can pose as a risk to animal health as they are capable of forming biofilms, which are commonly involved in fungal keratitis.


Assuntos
Antifúngicos/farmacologia , Azóis/farmacologia , Biofilmes/efeitos dos fármacos , Candida/efeitos dos fármacos , Túnica Conjuntiva/microbiologia , Anfotericina B/farmacologia , Animais , Candida/classificação , Candida/fisiologia , Candida/ultraestrutura , Caspofungina , Equinocandinas/farmacologia , Infecções Oculares Fúngicas/microbiologia , Infecções Oculares Fúngicas/veterinária , Fluconazol/farmacologia , Doenças dos Cavalos/microbiologia , Cavalos , Itraconazol/farmacologia , Ceratite/microbiologia , Ceratite/veterinária , Lipopeptídeos/farmacologia , Testes de Sensibilidade Microbiana
13.
Pharm Biol ; 55(1): 406-415, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27931150

RESUMO

CONTEXT: Uncaria tomentosa D.C. (Rubiaceae) has several biological activities, including activity against resistant Candida strains. The synergistic interaction with terbinafine or fluconazole can be an important alternative to overcome this resistance. OBJECTIVES: The potential synergy between a water insoluble fraction (WIF) from Uncaria tomentosa bark and the antifungals terbinafine (TRB) and fluconazole (FLZ) against non-Candida albicans resistant strains was investigated. MATERIALS AND METHODS: TRB and FLZ, alone and combined with WIF, were tested by the checkerboard procedure using the micro-dilution technique against seven isolates of Candida glabrata and C. krusei. The molecular interactions occurring outside the cell wall were evaluated by scanning electron microscopy, Fourier transform infrared (FT-IR) and differential scanning calorimetry (DSC) analysis. RESULTS: The checkerboard inhibitory assay demonstrated synergy for WIF:TRB and WIF:FLZ combinations, respectively. The best synergistic cell damage was demonstrated unequivocally for the associations of WIF and TRB (1.95:4.0 µg/mL) and WIF and FLZ (1.95:8.0 µg/mL). The comparison of the FT-IR spectra of the antifungal alone, and in combination with WIF, allows recognizing clear differences in 3000, 1600, 1400, and 700-800 cm-1 bands. Additionally, modifications on TRB and FLZ thermograms were clearly noticed after their combination with WIF. CONCLUSIONS: DSC and infrared analysis demonstrated intermolecular interactions between WIF and either TRB or FLZ. Hence, quite likely the synergistic effect is related to interaction events occurring outside the cell wall between antifungal and cat's claw proanthocyanidins. A direct action on the cell wall is suggested, without connection with the ABC efflux pump mechanism.


Assuntos
Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Unha-de-Gato/química , Farmacorresistência Fúngica/efeitos dos fármacos , Fluconazol/farmacologia , Naftalenos/farmacologia , Extratos Vegetais/farmacologia , Antifúngicos/isolamento & purificação , Varredura Diferencial de Calorimetria , Candida/crescimento & desenvolvimento , Candida/ultraestrutura , Parede Celular/efeitos dos fármacos , Parede Celular/ultraestrutura , Sinergismo Farmacológico , Microscopia Eletrônica de Varredura , Fitoterapia , Casca de Planta , Extratos Vegetais/isolamento & purificação , Plantas Medicinais , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Terbinafina , Água/química
14.
Yeast ; 33(2): 55-62, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26833628

RESUMO

Electron-microscopic examinations have demonstrated local modifications in the cell wall of the yeast Candida maltosa grown on hexadecane. In our earlier studies, these modified sites, observed in other yeasts grown on oil hydrocarbons, were conventionally called 'canals'. The biochemical and cytochemical studies of C. maltosa have revealed a correlation between the formation of 'canals' and decrease in the amount of cell wall polysaccharides, glucan and mannan. The ultrathin sections and surface replicas have shown that the 'canals' are destroyed by pronase, thus indicating that a significant proportion of their content is represented by proteins. This finding was compatible with our earlier data on the localization of oxidative enzymes in 'canals' and possible participation of the 'canals' in the primary oxidation of hydrocarbons. A completely unexpected and intriguing phenomenon has been the appearance of 'canals' in the yeast C. maltosa under starvation conditions. Unlike the yeasts grown on hexadecane, mannan almost disappears in starving cells, while the quantity of glucan first decreases and then is restored to its initial level. The role of 'canals' in starving cells is as yet unclear; it is assumed that they acquire exoenzymes involved in the utilization of products of cell lysis in the starving population. In the future, 'canals' of starving cells will be studied in connection with their possible participation in apoptosis.


Assuntos
Alcanos/metabolismo , Candida/crescimento & desenvolvimento , Parede Celular/ultraestrutura , Candida/metabolismo , Candida/ultraestrutura , Parede Celular/química , Meios de Cultura , Hidrolases/metabolismo , Mananas/metabolismo , Microscopia Eletrônica
15.
J Pept Sci ; 22(1): 28-35, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26680221

RESUMO

The incidence of life-threatening invasive fungal infections increased significantly in recent years. However, the antifungal therapeutic options are very limited. Antimicrobial peptides are a class of potential lead chemical for the development of novel antifungal agents. Antimicrobial peptide polybia-CP was purified from the venom of the social wasp Polybia paulista. In this study, we synthesized polybia-CP and determined its antifungal effects against a series of Candidian species. Our results showed that polybia-CP has potent antifungal activity and fungicidal activity against the tested fungal cells with a proposed membrane-active action mode. In addition, polybia-CP could induce the increase of cellular reactive oxygen species production, which would attribute to its antifungal activity. In conclusion, the present study suggests that polybia-CP has potential as an antifungal agent or may offer a new strategy for antifungal therapeutic option.


Assuntos
Antifúngicos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Candida/efeitos dos fármacos , Proteínas de Insetos/farmacologia , Venenos de Vespas/química , Animais , Antifúngicos/síntese química , Antifúngicos/isolamento & purificação , Peptídeos Catiônicos Antimicrobianos/síntese química , Peptídeos Catiônicos Antimicrobianos/isolamento & purificação , Candida/crescimento & desenvolvimento , Candida/metabolismo , Candida/ultraestrutura , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Membrana Celular/ultraestrutura , Parede Celular/efeitos dos fármacos , Parede Celular/metabolismo , Parede Celular/ultraestrutura , Eritrócitos/efeitos dos fármacos , Hemólise/efeitos dos fármacos , Humanos , Proteínas de Insetos/síntese química , Proteínas de Insetos/isolamento & purificação , Testes de Sensibilidade Microbiana , Ligação Proteica , Espécies Reativas de Oxigênio/agonistas , Espécies Reativas de Oxigênio/metabolismo , Vespas
16.
Mycoses ; 59(11): 734-741, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27427490

RESUMO

Candida wangnamkhiaoensis is a species clustered under the Hyphopichia clade has not ever been isolated from any clinical specimens. To the best of our knowledge, this is the first report of C. wangnamkhiaoensis associated with fungaemia in immunocompromised paediatric patient. The isolate was assigned a strain name as UZ1679/14, in which the identification was confirmed by a polymerase chain reaction-sequencing of the internal transcribed spacer (ITS) and large subunit (LSU) regions of the rRNA gene. Antifungal susceptibility pattern showed that the isolate was sensitive to anidulafungin, caspofungin, fluconazole and voriconazole. The patient clinically improved after the antifungal treatment with caspofungin.


Assuntos
Candida/isolamento & purificação , Candidemia/microbiologia , Hospedeiro Imunocomprometido , Anidulafungina , Antifúngicos/farmacologia , Candida/classificação , Candida/genética , Candida/ultraestrutura , Candidemia/tratamento farmacológico , Candidemia/imunologia , Caspofungina , Pré-Escolar , DNA Espaçador Ribossômico , Equinocandinas/farmacologia , Equinocandinas/uso terapêutico , Fluconazol/farmacologia , Humanos , Hifas/isolamento & purificação , Hifas/ultraestrutura , Lipopeptídeos/farmacologia , Lipopeptídeos/uso terapêutico , Masculino , Filogenia , Reação em Cadeia da Polimerase , Alinhamento de Sequência , Voriconazol/farmacologia
17.
Eur J Clin Microbiol Infect Dis ; 34(10): 2023-8, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26223323

RESUMO

This study was a detailed microscopic analysis of the changes of vaginal microflora characteristics after application of 0.03 mg estriol-lactobacilli combination on the vaginal ecosystem in postmenopausal breast cancer (BC) survivors on aromatase inhibitors (AI) with severe atrophic vaginitis. A total of 16 BC women on AI applied daily one vaginal tablet of Gynoflor® for 28 days followed by a maintenance therapy of three tablets weekly for 8 weeks. During four follow up visits a smear from the upper lateral vaginal wall was analysed by phase contrast microscopy at 400 times magnification in order to classify the lactobacillary grades(LBG), bacterial vaginosis (BV), aerobic vaginitis (AV), vulvovaginal candidosis (VVC), proportional number of leukocytes and evidence of parabasal cells and epitheliolysis. LBG improved from 81% LBG-III at entry to 88% LBG-I&IIa after 2 weeks of initial therapy, which further improved upon follow up (p < 0.001). Whereas BV was a rare event, AV was frequent and substantially improved during treatment (p < 0.01). While at entry most patients had moderate or severe AV, after maintenance therapy no patient except one had AV. The number of leukocytes dropped dramatically from a score of 1.78 ± 0.70 to 1.06 ± 0.25 which was consistent till the end of the study (p < 0.01). Parabasal cells dropped from a score of 3.4 ± 0.64 at entry to 1.3 ± 0.60 at the final visit (p trend < 0.01). Starting from a low rate of Candida colonisation of 2/14 (14%), a sudden rise to 7/16 (44%) occurred after 2 weeks, to return back to base levels at subsequent visits. The vaginal use of ultra-low dose estriol and lactobacilli results in rapid and enduring improvement of all markers of the vaginal microflora and epithelial vaginal cell quality in women with breast cancer on AI with dyspareunia. Candida may develop soon after its use, but rapidly disappears again upon their prolonged use. Due to its excellent safety profiles and clinical efficacy we recommend this product as first choice in women on AI with severe dyspareunia.


Assuntos
Inibidores da Aromatase/efeitos adversos , Neoplasias da Mama/tratamento farmacológico , Candidíase Vulvovaginal/tratamento farmacológico , Doenças Transmissíveis/tratamento farmacológico , Estriol/administração & dosagem , Inflamação/tratamento farmacológico , Vaginose Bacteriana/tratamento farmacológico , Administração Intravaginal , Adulto , Biomarcadores/sangue , Candida/ultraestrutura , Ecossistema , Estriol/farmacocinética , Feminino , Humanos , Lactobacillus acidophilus/ultraestrutura , Pessoa de Meia-Idade , Pós-Menopausa , Comprimidos , Vagina/efeitos dos fármacos , Vagina/microbiologia , Cremes, Espumas e Géis Vaginais , Vaginose Bacteriana/microbiologia
18.
Adv Exp Med Biol ; 830: 157-79, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25366227

RESUMO

Different types of central venous catheters (CVCs) have been used in clinical practice to improve the quality of life of chronically and critically ill patients. Unfortunately, indwelling devices are usually associated with microbial biofilms and eventually lead to catheter-related bloodstream infections (CLABSIs).An estimated 250,000-400,000 CLABSIs occur every year in the United States, at a rate of 1.5 per 1,000 CVC days and a mortality rate of 12-25 %. The annual cost of caring for patients with CLABSIs ranges from 296 million to 2.3 billion dollars.Biofilm formation occurs on biotic and abiotic surfaces in the clinical setting. Extensive studies have been conducted to understand biofilm formation, including different biofilm developmental stages, biofilm matrix compositions, quorum-sensing regulated biofilm formation, biofilm dispersal (and its clinical implications), and multi-species biofilms that are relevant to polymicrobial infections.When microbes form a matured biofilm within human hosts through medical devices such as CVCs, the infection becomes resistant to antibiotic treatment and can develop into a chronic condition. For that reason, many techniques have been used to prevent the formation of biofilm by targeting different stages of biofilm maturation. Other methods have been used to diagnose and treat established cases of CLABSI.Catheter removal is the conventional management of catheter associated bacteremia; however, the procedure itself carries a relatively high risk of mechanical complications. Salvaging the catheter can help to minimize these complications.In this article, we provide an overview of microbial biofilm formation; describe the involvement of various genetic determinants, adhesion proteins, organelles, mechanism(s) of biofilm formation, polymicrobial infections, and biofilm-associated infections on indwelling intravascular catheters; and describe the diagnosis, management, and prevention of catheter-related bloodstream infections.


Assuntos
Biofilmes/crescimento & desenvolvimento , Infecções Relacionadas a Cateter/sangue , Infecções Relacionadas a Cateter/microbiologia , Cateterismo Venoso Central/métodos , Consórcios Microbianos/fisiologia , Bactérias/classificação , Bactérias/ultraestrutura , Candida/classificação , Candida/ultraestrutura , Infecções Relacionadas a Cateter/etiologia , Cateterismo Venoso Central/efeitos adversos , Cateteres de Demora/efeitos adversos , Humanos , Microscopia Eletrônica
19.
Adv Exp Med Biol ; 830: 123-36, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25366225

RESUMO

Total laryngectomy is performed in advanced laryngeal and hypopharyngeal cancer stages and results in reduced quality of life due to the loss of voice and smell, permanent tracheostoma and occasionally dysphagia. Therefore, successful voice rehabilitation is highly beneficial for the patients' quality of life after surgery. Over the past decades, voice prostheses have evolved to the gold standard in rehabilitation and allow faster and superior voicing results after laryngectomy compared to esophageal speech. Polyspecies biofilm formation has become the limiting factor for device lifetimes and causes prosthesis dysfunction, leakage and in consequence pneumonia, if not replaced immediately. Although major improvements in prosthesis design have been made and scientific insight in the complexity of biofilm evolution and material interaction progresses, the microbial colonization continues to restrict device lifetimes, causing patient discomfort and elevated health costs. However, present scientific findings and advances in technology yield promising future approaches to improve the situation for laryngectomized patients.


Assuntos
Biofilmes/crescimento & desenvolvimento , Laringe Artificial/microbiologia , Consórcios Microbianos/fisiologia , Infecções Relacionadas à Prótese/microbiologia , Bactérias/classificação , Bactérias/isolamento & purificação , Bactérias/ultraestrutura , Candida/classificação , Candida/isolamento & purificação , Candida/ultraestrutura , Humanos , Laringectomia/efeitos adversos , Microscopia Confocal , Microscopia Eletrônica de Varredura , Infecções Relacionadas à Prótese/etiologia , Infecções Relacionadas à Prótese/prevenção & controle
20.
Med Microbiol Immunol ; 203(1): 25-33, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24013184

RESUMO

Candida invasive infections have increased in frequency during the last decades. Such infections are often associated to medical indwelling devices like central venous catheter. The recurrent nature and difficulties in the treatment of these infections are often related to biofilm formation. The objective of this study was to investigate the anti-biofilm activity of low-molecular weight chitosan hydrogel (LMWCH), a natural biopolymer obtained from the N-deacylation of crustacean chitin, upon clinical relevant Candida species. The in vitro ability of LMWCH to impair biofilm formation and to disorganize a preformed biofilm was tested in polystyrene microplates and quantified by the semi quantitative XTT assay and by the crystal violet assay. LMWCH in vivo efficacy as a coating for medical indwelling devices was evaluated for the first time for Candida parapsilosis, using a mouse subcutaneous foreign body model using polyurethane catheter segments. Scanning electron microscopy was used to access biofilm architecture after LMWCH treatment. We found that LMWCH efficiently impaired biofilm formation of all Candida species, also promoting biofilm disaggregation. Most importantly, LMWCH was able to significantly inhibit biofilm formation by C. parapsilosis in an in vivo catheter mouse model. SEM images showed biofilm collapsed cells compatible with membrane damage, suggesting that this could be one of the possible mechanisms underlying biofilm impairment. LMWCH revealed to be a promising compound for treatment of candidiasis or its prevention through medical device coating.


Assuntos
Biofilmes/efeitos dos fármacos , Candida/efeitos dos fármacos , Candida/fisiologia , Quitosana/farmacologia , Hidrogel de Polietilenoglicol-Dimetacrilato , Animais , Candida/ultraestrutura , Candidíase/tratamento farmacológico , Candidíase/microbiologia , Quitosana/administração & dosagem , Quitosana/química , Feminino , Humanos , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Camundongos , Testes de Sensibilidade Microbiana , Peso Molecular , Plâncton/efeitos dos fármacos
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