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2.
Braz J Microbiol ; 55(3): 2655-2667, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38888692

RESUMO

Sporotrichosis is recognized as the predominant subcutaneous mycosis in South America, attributed to pathogenic species within the Sporothrix genus. Notably, in Brazil, Sporothrix brasiliensis emerges as the principal species, exhibiting significant sapronotic, zoonotic and enzootic epidemic potential. Consequently, the discovery of novel therapeutic agents for the treatment of sporotrichosis is imperative. The present study is dedicated to the repositioning of pharmaceuticals for sporotrichosis therapy. To achieve this goal, we designed a pipeline with the following steps: (a) compilation and preparation of Sporothrix genome data; (b) identification of orthologous proteins among the species; (c) identification of homologous proteins in publicly available drug-target databases; (d) selection of Sporothrix essential targets using validated genes from Saccharomyces cerevisiae; (e) molecular modeling studies; and (f) experimental validation of selected candidates. Based on this approach, we were able to prioritize eight drugs for in vitro experimental validation. Among the evaluated compounds, everolimus and bifonazole demonstrated minimum inhibitory concentration (MIC) values of 0.5 µg/mL and 4.0 µg/mL, respectively. Subsequently, molecular docking studies suggest that bifonazole and everolimus may target specific proteins within S. brasiliensis- namely, sterol 14-α-demethylase and serine/threonine-protein kinase TOR, respectively. These findings shed light on the potential binding affinities and binding modes of bifonazole and everolimus with their probable targets, providing a preliminary understanding of the antifungal mechanism of action of these compounds. In conclusion, our research advances the understanding of the therapeutic potential of bifonazole and everolimus, supporting their further investigation as antifungal agents for sporotrichosis in prospective hit-to-lead and preclinical investigations.


Assuntos
Antifúngicos , Reposicionamento de Medicamentos , Genoma Fúngico , Testes de Sensibilidade Microbiana , Sporothrix , Esporotricose , Sporothrix/efeitos dos fármacos , Sporothrix/genética , Antifúngicos/farmacologia , Esporotricose/microbiologia , Esporotricose/tratamento farmacológico , Brasil , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/química , Simulação de Acoplamento Molecular , Genômica , Humanos , Avaliação Pré-Clínica de Medicamentos , Descoberta de Drogas , Biologia Computacional
3.
J Mycol Med ; 33(2): 101363, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36842411

RESUMO

BACKGROUND: Histoplasmosis is a systemic form of endemic mycosis to the American continent and may be lethal to people living with HIV/AIDS. The drugs available for treating histoplasmosis are limited, costly, and highly toxic. New drug development is time-consuming and costly; hence, drug repositioning is an advantageous strategy for discovering new therapeutic options. OBJECTIVE: This study was conducted to identify drugs that can be repositioned for treating histoplasmosis in immunocompromised patients. METHODS: Homologous proteins among Histoplasma capsulatum strains were selected and used to search for homologous targets in the DrugBank and Therapeutic Target Database. Essential genes were selected using Saccharomyces cerevisiae as a model, and functional regions of the therapeutic targets were analyzed. The antifungal activity of the selected drugs was verified, and homology modeling and molecular docking were performed to verify the interactions between the drugs with low inhibitory concentration values and their corresponding targets. RESULTS: We selected 149 approved drugs with potential activity against histoplasmosis, among which eight were selected for evaluating their in vitro activity. For drugs with low minimum inhibitory concentration values, such as mebendazole, everolimus, butenafine, and bifonazole, molecular docking studies were performed. A chemogenomic framework revealed lanosterol 14-α-demethylase, squalene monooxygenase, serine/threonine-protein kinase mTOR, and the ß-4B tubulin chain of H. capsulatum, respectively, as the protein targets of the drugs. CONCLUSIONS: Our strategy can be used to identify promising antifungal targets, and drugs with repositioning potential for treating H. capsulatum.


Assuntos
Infecções Oportunistas Relacionadas com a AIDS , Histoplasmose , Humanos , Histoplasmose/epidemiologia , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Infecções Oportunistas Relacionadas com a AIDS/microbiologia , Reposicionamento de Medicamentos , Simulação de Acoplamento Molecular , Histoplasma/genética
4.
Braz J Microbiol ; 54(1): 125-133, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36371517

RESUMO

Oropharyngeal candidiasis (OPC) is the most common opportunistic fungal infection of the oral cavity and is a significant clinical problem, particularly in immunocompromised individuals, such as people living with HIV/AIDS (PLWHA). Although Candida albicans is the most frequent pathogen, at least 30 species capable of causing infection have been described. Identifying the infecting organism is necessary because the species respond differently to therapy, and antifungal susceptibility testing is important to determine the appropriate treatment. This study aimed to determine the epidemiological, clinical, and mycological profiles of OPC in hospitalized PLWHA. Clinical samples were collected from 103 PLWHA with suspected candidiasis admitted to the Hospital Estadual of Doenças Tropicais/Hospital Anuar Auad of Goiania, Goias, Brazil, for 14 months. Candida species were identified using phenotypic microbiological techniques and molecular analysis performed by PCR using species-specific primers. The antifungal susceptibility pattern of the isolates against the six antifungal agents was determined using the broth microdilution method. Here, female individuals were the most affected by OPC, presenting a higher risk of oral colonization by Candida spp. The main clinical manifestation was pseudomembranous candidiasis. The number of cases of candidiasis was 87.3% (90/103), with C. albicans being the most common species, followed by C. tropicalis and C. glabrata. In the susceptibility pattern, non-albicans Candida showed higher resistance to than C. albicans. The fast and accurate identification of Candida spp. is very important to identify therapeutic agents for the treatment of oral candidiasis in PLWHA.


Assuntos
Síndrome da Imunodeficiência Adquirida , Candidíase Bucal , Candidíase , Humanos , Feminino , Antifúngicos/farmacologia , Candida , Brasil , Farmacorresistência Fúngica , Candidíase Bucal/microbiologia , Candidíase/microbiologia , Candida albicans , Candida glabrata , Hospitais Públicos , Testes de Sensibilidade Microbiana
5.
Braz J Microbiol ; 51(4): 1719-1727, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32856241

RESUMO

Punicalagin is a phenolic compound extracted from Lafoensia pacari A. St.-Hil (Lythraceae) leaves. It has demonstrated interesting activity against pathogenic fungi, e.g., Cryptococcus gattii and Candida albicans, by inhibiting fungi growth in a minimum inhibitory concentration (MIC) at 4 µg/mL. However, the mechanisms behind its antifungal action are not well understood. In this study, certain parameters were investigated, by transmission electron microscopy, ergosterol synthesis inhibition, and flow cytometry analyses, to gain insight into the possible biological targets of punicalagin (4 or 16 µg/mL) against yeast cells. Data showed that, in contrast to untreated cells, punicalagin triggered severe ultrastructural changes in C. gattii and C. albicans, such as disorganization of cytoplasmic content and/or thickened cell walls. In addition, it caused a decrease in yeast plasma membrane ergosterol content in a concentration-dependent manner. However, it was unable to bring about significant fungal cell membrane rupture. On the other hand, punicalagin (16 µg/mL) significantly arrested C. albicans and C. gattii cells at the G0/G1 phase, with a consequent reduction in cells at the G2/M phase in both fungi isolates, and thereby prevented progression of the normal yeast cell cycle. However, these alterations showed no involvement of reactive oxygen species overproduction in C. albicans and C. gattii cells, although punicalagin triggered a significant loss of mitochondrial membrane potential in C. albicans. These findings suggest that punicalagin is a promising plant-derived compound for use in developing new antifungal therapies.


Assuntos
Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Cryptococcus gattii/efeitos dos fármacos , Ergosterol/metabolismo , Taninos Hidrolisáveis/farmacologia , Candida albicans/crescimento & desenvolvimento , Candida albicans/metabolismo , Candida albicans/ultraestrutura , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Cryptococcus gattii/crescimento & desenvolvimento , Cryptococcus gattii/metabolismo , Cryptococcus gattii/ultraestrutura , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Microscopia Eletrônica de Transmissão
6.
Med Mycol ; 58(7): 881-886, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32022862

RESUMO

The hospital environment requires special attention to air quality, since it needs to be healthy for the protection of patients and health professionals in order to prevent them against hospital infections. The objective of this study was to isolate, identify and evaluate the susceptibility profile of isolated fungi from two hospitals. For air sampling the impaction (Spin Air, IUL®) and passive sedimentation methods were used. For the isolation of fungi from surfaces, contact plates (RODAC®) were used. The identification of the fungi was performed by observing the macroscopic and microscopic aspects of the colonies, whereas for better visualization of fruiting structures, the microculture technique was performed on slides. To evaluate the susceptibility profile, the broth microdilution test recommended by CLSI was performed. Thirty-five isolates were identified: Aspergillus flavus (12), Aspergillus fumigatus (11), Aspergillus niger (1), Aspergillus terreus (2), Penicillium spp. (7), and Fusarium spp. (2) in the hospitals evaluated. All isolates had a minimum inhibitory concentration (MIC) more than 128 µg/ml for fluconazole; 0.5 to 4.0 µg/ml for amphotericin B (hospital 1), and all isolates from haospital 2 had MIC ≥2.0 µg/ml. In hospital 1, MIC for posaconazole ranged from 0.25 µg/ml to ≥32 µg/ml, and hospital 2 ranged from 0.5 to 1.0 µg/ml. The monitoring and evaluation of air quality and surfaces are essential measures for prevention and control of hospital infections, as these microorganisms are becoming increasingly resistant to antimicrobial agents, thus making treatment difficult, especially in immunocompromised individuals.


Assuntos
Antifúngicos/administração & dosagem , Aspergillus/isolamento & purificação , Equipamentos Médicos Duráveis/microbiologia , Fusarium/isolamento & purificação , Doença Iatrogênica/prevenção & controle , Penicillium/isolamento & purificação , Esterilização/métodos , Humanos , Unidades de Terapia Intensiva , Salas Cirúrgicas , Estudos Prospectivos , Sala de Recuperação , Medição de Risco
7.
Rev Soc Bras Med Trop ; 53: e20190336, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31994664

RESUMO

INTRODUCTION: Candida parapsilosis complex species differ from each other with regard to their prevalence and virulence. METHODS: The hydrolytic enzyme activity, biofilm production, and adhesion to epithelial cells were analyzed in 87 C. parapsilosis complex strains. RESULTS: Among the studied isolates, 97.7%, 63.2%, and 82.8% exhibited very strong proteinase, esterase, and hemolysin activity, respectively. All the C. parapsilosis complex isolates produced biofilms and presented an average adherence of 96.0 yeasts/100 epithelial cells. CONCLUSIONS: Our results show that Candida parapsilosis complex isolates showed different levels of enzyme activity, biofilm production, and adhesion to epithelial cells.


Assuntos
Candida parapsilosis/patogenicidade , Fatores de Virulência/análise , Biofilmes/crescimento & desenvolvimento , Candida parapsilosis/classificação , Candida parapsilosis/enzimologia , Candida parapsilosis/isolamento & purificação , Adesão Celular , Humanos , Hidrolases/biossíntese , Técnicas de Tipagem Micológica
8.
Rev. patol. trop ; 49(3)2020.
Artigo em Inglês | LILACS | ID: biblio-1151969

RESUMO

Vulvovaginal candidiasis (VVC) is a common infection. This work aims to determine the positive predictive value (PPV) of the clinical diagnosis of VVC and to characterize Candida species isolated from the vaginal mucosa. This cross-sectional study was conducted from February 2016 to February 2017 at the Gynecology and Obstetrics Outpatient Clinic of the Hospital das Clínicas, in Goiânia, Goiás State, Brazil. The study included samples of vaginal secretion from 55 women who complained of vaginal discharge and itching as their main symptoms. The PPV of the clinical diagnosis of VVC was estimated in comparison to the laboratory culture method. The phenotypic methods and molecular tests were performed to identify Candida spp. In vitro susceptibility of Candida spp. isolates to fluconazole, itraconazole, clotrimazole, nystatin, and amphotericin B was determined using the broth microdilution assay. Yeast growth using the enzymes protease, phospholipase, and hemolysin was carried out in media containing respectively bovine albumin, egg yolk, and sheep erythrocytes. A PPV of 61.8% (34/55) was determined. Among the 55 vulvovaginal samples collected, we identified 36 isolates in which C. albicans was the most common species. High resistance to fluconazole and low minimal inhibitory concentration (MIC) values for clotrimazole, nystatin and amphotericin B were observed. All isolates were proteinase and hemolysin producers, while seven strains were phospholipase negative. The clinical diagnosis of VVC presented a moderate PPV, which meant that cultures had to be conducted in the laboratory to confirm infection. The high resistance to fluconazole and itraconazole indicated the importance of the in vitro susceptibility test.


Assuntos
Humanos , Feminino , Candidíase Vulvovaginal , Diagnóstico Clínico , Infecções do Sistema Genital
9.
Rev. Soc. Bras. Med. Trop ; 53: e20190336, 2020. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1057282

RESUMO

Abstract INTRODUCTION: Candida parapsilosis complex species differ from each other with regard to their prevalence and virulence. METHODS: The hydrolytic enzyme activity, biofilm production, and adhesion to epithelial cells were analyzed in 87 C. parapsilosis complex strains. RESULTS: Among the studied isolates, 97.7%, 63.2%, and 82.8% exhibited very strong proteinase, esterase, and hemolysin activity, respectively. All the C. parapsilosis complex isolates produced biofilms and presented an average adherence of 96.0 yeasts/100 epithelial cells. CONCLUSIONS: Our results show that Candida parapsilosis complex isolates showed different levels of enzyme activity, biofilm production, and adhesion to epithelial cells.


Assuntos
Humanos , Fatores de Virulência/análise , Candida parapsilosis/patogenicidade , Adesão Celular , Técnicas de Tipagem Micológica , Biofilmes/crescimento & desenvolvimento , Candida parapsilosis/isolamento & purificação , Candida parapsilosis/classificação , Candida parapsilosis/enzimologia , Hidrolases/biossíntese
10.
Rev Inst Med Trop Sao Paulo ; 60: e60, 2018 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-30365643

RESUMO

This study evaluated the antifungal activity and cytotoxicity profile of the ellagitannin punicalagin, a compound extracted from the L. pacari A. St.-Hil (Lythraceae) leaf, against Cryptococcus neoformans species complex. Minimum inhibitory concentrations (MIC) were checked using the broth microdilution method. Minimum fungicidal concentrations (MFC) and time of death were used to confirm the antifungal activity of the compound. The in vitro cytotoxicity of punicalagin was tested in BALB/c3T3 fibroblasts and A549 human lung cancer cell line, while the hemolytic potential was tested on sheep erythrocytes. The morphological changes induced in yeast strains by the presence of punicalagin were also analyzed. Tested on eight isolates of the C. neoformans complex punicalagin showed MIC of 0.5 to 4.0 µg/mL and MFC> 256 µg/mL. Punicalagin also demonstrated a good growth inhibitory activity in time-kill curves, but it was not able to achieve a statistically significant reduction of fungal growth suggesting a fungistatic effect of the compound. In vitro cytotoxicity studies using the two cell lines showed that punicalagin has low activity on these cells and no activity on sheep erythrocytes. Morphological changes were seen in the yeasts strains studied when treated with punicalagin. Therefore, punicalagin is a potential antifungal for important pathogenic yeasts and presents a low cytotoxicity profile associated with no hemolytic effects.


Assuntos
Antifúngicos/farmacologia , Cryptococcus neoformans/efeitos dos fármacos , Taninos Hidrolisáveis/farmacologia , Lythraceae/química , Folhas de Planta/química , Animais , Cryptococcus neoformans/isolamento & purificação , Testes Imunológicos de Citotoxicidade , Testes de Sensibilidade Microbiana
11.
Rev. patol. trop ; 47(1): 11-18, març. 2018. tab, ilus
Artigo em Inglês | LILACS | ID: biblio-913759

RESUMO

Although Candida albicans remains the most frequent Candida species; however other species have emerged as important causes of candidiasis. In this work, we evaluated the in vitro susceptibility profile of C. albicans, C. parapsilosis, and C. tropicalis biofilms isolated from patients with candidemia to fluconazole, voriconazole, amphotericin B, and caspofungin. Differences between the biofilm ultrastructure of the three species were also determined. The isolates were phenotypically determined by growth on a ChromagarTM medium and assimilation profile on ID32C. The Scanning Electron Microscopy method (SEM) on biofilm was performed using polyurethane strips. For the in vitro susceptibility profile a microdilution in broth was used. Sessile cells were resistant to fluconazole, voriconazole and caspofungin. The resistance to amphotericin B was less pronounced and more variable between the tested isolates. In the SEM, slight differences in ultrastructural morphology for each species in biofilms were observed. Our results verified biofilm formation. Low susceptibility to the drugs in the three researched species confirmed the higher virulence of them.


Assuntos
Biofilmes , Candida , Microscopia Eletrônica de Varredura , Suscetibilidade a Doenças
12.
Rev Soc Bras Med Trop ; 50(1): 80-85, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28327806

RESUMO

INTRODUCTION:: Invasive fungal infections (IFIs) are an important complication in immunocompromised individuals, particularly neutropenic patients with hematological malignancies. In this study, we aimed to verify the epidemiology and diagnosis of IFIs in patients with hematologic problems at a tertiary hospital in Goiânia-GO, Brazil. METHODS:: Data from 117 patients, involving 19 cases of IFIs, were collected. The collected data included diagnosis methods, demographics, clinical characteristics, and in vitro susceptibility to different antifungal agents. Among the 19 cases, 12 were classified as proven IFI and 7 as probable invasive aspergillosis with detection of galactomannan in blood and presence of lung infiltrates in radiographic images. Logistic regression analysis showed that the proven and probable IFIs were associated with increased risk of death. Statistical analysis demonstrated that age, sex, and underlying disease were not independently associated with risk of death in IFI patients. RESULTS:: Most bloodstream isolates of Candida spp. exhibited low minimum inhibitory concentrations (MICs) to all antifungal agents tested. Voriconazole and amphotericin had the lowest MICs for Aspergillus spp. and Fusarium spp., but Fusarium spp. showed the least susceptibility to all antifungals tested. Amphotericin B, fluconazole, and itraconazole were found to be inactive in vitro against Acremonium kiliense; but this fungus was sensitive to voriconazole. CONCLUSIONS:: Considering the high number of IFI cases, with crude mortality rate of 6%, we could conclude that IFIs remain a common infection in patients with hematological malignancies and underdiagnosed ante mortem. Thus, IFIs should be monitored closely.


Assuntos
Doenças Hematológicas/microbiologia , Infecções Fúngicas Invasivas/microbiologia , Acremonium/efeitos dos fármacos , Acremonium/isolamento & purificação , Adulto , Antifúngicos/farmacologia , Aspergillus/efeitos dos fármacos , Aspergillus/isolamento & purificação , Candida/efeitos dos fármacos , Candida/isolamento & purificação , Feminino , Fusarium/efeitos dos fármacos , Fusarium/isolamento & purificação , Galactose/análogos & derivados , Humanos , Hospedeiro Imunocomprometido , Infecções Fúngicas Invasivas/diagnóstico , Masculino , Mananas/sangue , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Prevalência , Sensibilidade e Especificidade , Adulto Jovem
13.
Rev. Soc. Bras. Med. Trop ; 50(1): 80-85, Jan.-Feb. 2017. tab, graf
Artigo em Inglês | LILACS | ID: biblio-842812

RESUMO

ABSTRACT INTRODUCTION: Invasive fungal infections (IFIs) are an important complication in immunocompromised individuals, particularly neutropenic patients with hematological malignancies. In this study, we aimed to verify the epidemiology and diagnosis of IFIs in patients with hematologic problems at a tertiary hospital in Goiânia-GO, Brazil. METHODS: Data from 117 patients, involving 19 cases of IFIs, were collected. The collected data included diagnosis methods, demographics, clinical characteristics, and in vitro susceptibility to different antifungal agents. Among the 19 cases, 12 were classified as proven IFI and 7 as probable invasive aspergillosis with detection of galactomannan in blood and presence of lung infiltrates in radiographic images. Logistic regression analysis showed that the proven and probable IFIs were associated with increased risk of death. Statistical analysis demonstrated that age, sex, and underlying disease were not independently associated with risk of death in IFI patients. RESULTS: Most bloodstream isolates of Candida spp. exhibited low minimum inhibitory concentrations (MICs) to all antifungal agents tested. Voriconazole and amphotericin had the lowest MICs for Aspergillus spp. and Fusarium spp., but Fusarium spp. showed the least susceptibility to all antifungals tested. Amphotericin B, fluconazole, and itraconazole were found to be inactive in vitro against Acremonium kiliense; but this fungus was sensitive to voriconazole. CONCLUSIONS: Considering the high number of IFI cases, with crude mortality rate of 6%, we could conclude that IFIs remain a common infection in patients with hematological malignancies and underdiagnosed ante mortem. Thus, IFIs should be monitored closely.


Assuntos
Humanos , Masculino , Feminino , Adulto , Adulto Jovem , Infecções Fúngicas Invasivas/microbiologia , Doenças Hematológicas/microbiologia , Aspergillus/isolamento & purificação , Aspergillus/efeitos dos fármacos , Acremonium/isolamento & purificação , Acremonium/efeitos dos fármacos , Candida/isolamento & purificação , Candida/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Prevalência , Sensibilidade e Especificidade , Hospedeiro Imunocomprometido , Infecções Fúngicas Invasivas/diagnóstico , Fusarium/isolamento & purificação , Fusarium/efeitos dos fármacos , Mananas/sangue , Pessoa de Meia-Idade , Antifúngicos/farmacologia
14.
Rev Soc Bras Med Trop ; 48(4): 454-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26312937

RESUMO

INTRODUCTION: Candida parapsilosis is a common yeast species found in cases of onychomycosis and candidemia associated with infected intravascular devices. In this study, we differentiated Candida parapsilosis sensu stricto, Candida orthopsilosis , and Candida metapsilosis from a culture collection containing blood and subungual scraping samples. Furthermore, we assessed the in vitro antifungal susceptibility of these species to fluconazole, itraconazole, voriconazole, posaconazole, amphotericin B, and caspofungin. METHODS: Differentiation of C. parapsilosis complex species was performed by amplification of the secondary alcohol dehydrogenase (SADH) gene and digestion by the restriction enzyme Ban I. All isolates were evaluated for the determination of minimal inhibitory concentrations using Etest, a method for antifungal susceptibility testing. RESULTS: Among the 87 isolates, 78 (89.7%) were identified as C. parapsilosis sensu stricto , five (5.7%) were identified as C. orthopsilosis , and four (4.6%) were identified as C. metapsilosis . Analysis of antifungal susceptibility showed that C. parapsilosis sensu strictoisolates were less susceptible to amphotericin B and itraconazole. One C. parapsilosis sensu stricto isolate was resistant to amphotericin B and itraconazole. Moreover, 10.2% of C. parapsilosis sensu stricto isolates were resistant to caspofungin. Two C. parapsilosis sensu strictoisolates and one C. metapsilosis isolate were susceptible to fluconazole in a dose-dependent manner. CONCLUSIONS: We reported the first molecular identification of C. parapsilosiscomplex species in State of Goiás, Brazil. Additionally, we showed that although the three species exhibited differences in antifungal susceptibility profiles, the primary susceptibility of this species was to caspofungin.


Assuntos
Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Adulto , Candida/classificação , Farmacorresistência Fúngica , Humanos , Testes de Sensibilidade Microbiana , Técnicas de Tipagem Micológica/métodos
15.
Rev. Soc. Bras. Med. Trop ; 48(4): 454-459, July-Aug. 2015. tab, ilus
Artigo em Inglês | LILACS | ID: lil-755974

RESUMO

AbstractINTRODUCTION:

Candida parapsilosis is a common yeast species found in cases of onychomycosis and candidemia associated with infected intravascular devices. In this study, we differentiated Candida parapsilosis sensu stricto, Candida orthopsilosis , and Candida metapsilosis from a culture collection containing blood and subungual scraping samples. Furthermore, we assessed the in vitro antifungal susceptibility of these species to fluconazole, itraconazole, voriconazole, posaconazole, amphotericin B, and caspofungin.

METHODS:

Differentiation of C. parapsilosis complex species was performed by amplification of the secondary alcohol dehydrogenase (SADH) gene and digestion by the restriction enzyme Ban I. All isolates were evaluated for the determination of minimal inhibitory concentrations using Etest, a method for antifungal susceptibility testing.

RESULTS:

Among the 87 isolates, 78 (89.7%) were identified as C. parapsilosis sensu stricto , five (5.7%) were identified as C. orthopsilosis , and four (4.6%) were identified as C. metapsilosis . Analysis of antifungal susceptibility showed that C. parapsilosis sensu strictoisolates were less susceptible to amphotericin B and itraconazole. One C. parapsilosis sensu stricto isolate was resistant to amphotericin B and itraconazole. Moreover, 10.2% of C. parapsilosis sensu stricto isolates were resistant to caspofungin. Two C. parapsilosis sensu strictoisolates and one C. metapsilosis isolate were susceptible to fluconazole in a dose-dependent manner.

CONCLUSIONS:

We reported the first molecular identification of C. p...


Assuntos
Adulto , Humanos , Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Candida/classificação , Farmacorresistência Fúngica , Testes de Sensibilidade Microbiana , Técnicas de Tipagem Micológica/métodos
16.
Rev Soc Bras Med Trop ; 47(5): 618-23, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25467265

RESUMO

INTRODUCTION: This is the first study to examine the in vitro susceptibility and the expression of virulence factors in Candida species in the presence of Pimenta pseudocaryophyllus (Gomes) L.R. Landrum (Myrtaceae), a Brazilian plant known as paucravo. Additionally, the mechanisms of action of the crude ethanol extract and the ethyl acetate and aqueous fractions of this plant were investigated. METHODS: The in vitro susceptibility of Candida was tested using the broth microdilution method, whereas an XTT reduction assay was used for biofilms. Adherence was determined by counting the number of yeast cells that adhered to 100 oral epithelial cells, and hyphal formation was verified in the hyphal induction medium M199. Flow cytometry with propidium iodide and FUN-1 was performed to assess the mechanism of action. RESULTS: The results revealed that the crude ethanol extract and the ethyl acetate and aqueous fractions of P. pseudocaryophyllus inhibited the growth of Candida isolates at a minimal inhibitory concentration (MIC) ranging from 64 to 256 µg/mL, whereas the 50% sessile minimal inhibitory concentration (SMIC50) ranged from 512 to >1,024 µg/mL. Adherence and hyphal formation were significantly reduced in the presence of the crude ethanol extract and both fractions. Although cell membrane injury was detected, the predominant mechanism of action appeared to be the alteration of yeast metabolism, as demonstrated by flow cytometry. CONCLUSIONS: Our results indicated that antifungal activity reduced the expression of virulence factors in yeast via the alteration of yeast metabolism, suggesting that the crude extract of P. pseudocaryophyllus and its fractions may contain novel antifungal agents.


Assuntos
Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Pimenta/química , Extratos Vegetais/farmacologia , Fatores de Virulência/antagonistas & inibidores , Antifúngicos/isolamento & purificação , Biofilmes/efeitos dos fármacos , Candida/patogenicidade , Citometria de Fluxo , Humanos , Dose Letal Mediana , Testes de Sensibilidade Microbiana
17.
Rev. Soc. Bras. Med. Trop ; 47(5): 618-623, Sep-Oct/2014. tab, graf
Artigo em Inglês | LILACS | ID: lil-728892

RESUMO

Introduction This is the first study to examine the in vitro susceptibility and the expression of virulence factors in Candida species in the presence of Pimenta pseudocaryophyllus (Gomes) L.R. Landrum (Myrtaceae), a Brazilian plant known as paucravo. Additionally, the mechanisms of action of the crude ethanol extract and the ethyl acetate and aqueous fractions of this plant were investigated. Methods The in vitro susceptibility of Candida was tested using the broth microdilution method, whereas an XTT reduction assay was used for biofilms. Adherence was determined by counting the number of yeast cells that adhered to 100 oral epithelial cells, and hyphal formation was verified in the hyphal induction medium M199. Flow cytometry with propidium iodide and FUN-1 was performed to assess the mechanism of action. Results The results revealed that the crude ethanol extract and the ethyl acetate and aqueous fractions of P. pseudocaryophyllus inhibited the growth of Candida isolates at a minimal inhibitory concentration (MIC) ranging from 64 to 256µg/mL, whereas the 50% sessile minimal inhibitory concentration (SMIC50) ranged from 512 to >1,024µg/mL. Adherence and hyphal formation were significantly reduced in the presence of the crude ethanol extract and both fractions. Although cell membrane injury was detected, the predominant mechanism of action appeared to be the alteration of yeast metabolism, as demonstrated by flow cytometry. Conclusions Our results indicated that antifungal activity reduced the expression of virulence factors in yeast via the alteration of yeast metabolism, suggesting that the crude extract of P. pseudocaryophyllus and its fractions may contain novel antifungal agents. .


Assuntos
Humanos , Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Pimenta/química , Extratos Vegetais/farmacologia , Fatores de Virulência/antagonistas & inibidores , Antifúngicos/isolamento & purificação , Biofilmes/efeitos dos fármacos , Candida/patogenicidade , Citometria de Fluxo , Testes de Sensibilidade Microbiana
18.
BMC Complement Altern Med ; 14: 245, 2014 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-25027026

RESUMO

BACKGROUND: The great potential of plants as Hymenaea courbaril L (jatoba) has not yet been throughly explored scientifically and therefore it is very important to investigate their pharmacological and toxicological activities to establish their real efficacy and safety. This study investigated the cytotoxicity of xylem sap of Hymenaea courbaril L and its bioactivity against the fungi Cryptococcus neoformans species complex and dermatophytes. METHODS: The fresh xylem sap of H. courbaril was filtered resulting in an insoluble brown color precipitate and was identified as fisetin. In the filtrate was identified the mixture of fisetinediol, fustin, 3-O-methyl-2,3-trans-fustin and taxifolin, which were evaluated by broth microdilution antifungal susceptibility testing against C. neoformans species complex and dermatophytes. The fresh xylem sap and fisetin were screened for cytotoxicity against the 3T3-A31 cells of Balb/c using neutral red uptake (NRU) assay. RESULTS: The fresh xylem sap and the fisetin showed higher in vitro activity than the filtrate. The xylem sap of H. courbaril inhibited the growth of dermatophytes and of C. neoformans with minimal inhibition concentration (MIC) < 256 µg/mL, while the fisetin showed MIC < 128 µg/mL for these fungi. Fisetin showed lower toxicity (IC50 = 158 µg/mL) than the fresh xylem sap (IC50 = 109 µg/mL). CONCLUSION: Naturally occurring fisetin can provide excellent starting points for clinical application and can certainly represent a therapeutic potential against fungal infections, because it showed in vitro antifungal activity and low toxicity on animal cells.


Assuntos
Antifúngicos/farmacologia , Flavonoides/farmacologia , Hymenaea/química , Xilema/química , Animais , Antifúngicos/química , Antifúngicos/isolamento & purificação , Arthrodermataceae/efeitos dos fármacos , Linhagem Celular , Cryptococcus neoformans/efeitos dos fármacos , Flavonoides/química , Flavonoides/isolamento & purificação , Flavonóis , Camundongos , Testes de Sensibilidade Microbiana
19.
Mycopathologia ; 176(5-6): 417-21, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24002104

RESUMO

Changes in the spectrum of clinically important fungal infection have been observed in recent years. Acremonium species has been responsible for eumycotic mycetomas but has also been increasingly implicated in systemic fungal diseases. A case of Acremonium kiliense fungemia with proven involvement of the lungs in an allogeneic hematopoietic stem cell patient is reported. A high-resolution computed tomography scan of the lungs showed nodules in both lungs. Multiple cultures of blood demonstrated narrow septate hyphae, cylindrical conidia, and solitary tapering phialides and microconidia that remained grouped in slimy heads. The isolate was identified as A. kiliense based on its morphological characteristics and DNA sequence analysis. Susceptibility testing of the clinical isolate was performed to four antifungal agents. Amphotericin B, fluconazole and itraconazole were found to be inactive in vitro against the isolate; however, it was found to be sensitive to voriconazole. This last drug was indicated, and a high-resolution computed tomography scan of the lungs was normal after 10 days. One year later, the patient was free of symptoms and her blood culture was negative for fungi. Thus, voriconazole was effective in treatment for life-threatening A. kiliense infections. In this work, we performed an overview of worldwide clinical infections caused by A. kiliense.


Assuntos
Acremonium/isolamento & purificação , Fungemia/diagnóstico , Fungemia/microbiologia , Pneumopatias Fúngicas/diagnóstico , Pneumopatias Fúngicas/microbiologia , Acremonium/classificação , Acremonium/citologia , Adulto , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Feminino , Fungemia/complicações , Transplante de Células-Tronco Hematopoéticas , Humanos , Hospedeiro Imunocomprometido , Pulmão/patologia , Pneumopatias Fúngicas/complicações , Técnicas Microbiológicas , Microscopia , RNA Ribossômico 5,8S/genética , Radiografia Torácica , Análise de Sequência de DNA , Tomografia Computadorizada por Raios X , Transplante , Transplante Homólogo
20.
Rev Soc Bras Med Trop ; 46(3): 343-7, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23856876

RESUMO

INTRODUCTION: In this study, the clinical features, underlying diseases and clinical outcomes of patients with cryptococcosis were investigated. In addition, a molecular analysis of the Cryptococcus neoformans species complex isolated from these patients was performed. METHODS: A prospective study of 62 cases of patients with cryptococcal infection was conducted at the Hospital de Doenças Tropicais de Goiás Dr. Anuar Auad from 2009-2010. Cryptococcal meningitis cases were diagnosed by direct examination and cerebrospinal fluid (CSF) sample culture. The profiling of these patients was assessed. The CSF samples were submitted to India ink preparation and cultured on Sabouraud dextrose agar, and C. neoformans was identified by the production of urease, a positive phenoloxidase test and assimilation of carbohydrates. C. neoformans and C. gattii isolates were distinguished by growth on L-canavanine-glycine-bromothymol blue medium, and molecular analysis was conducted via PCR fingerprinting reactions using M13 and (GACA)4 primers. RESULTS: From the 62 patients with cryptococcosis, 71 isolates of CSF were obtained; 67 (94.4%) isolates were identified as C. neoformans var. grubii/VNI, and 4 (5.6%) were identified as C. gattii/VGII. Of these patients, 53 had an HIV diagnosis. The incidence of cryptococcosis was higher among patients 20-40 years of age, with 74.2% of the cases reported in males. Cryptococcus-related mortality was noted in 48.4% of the patients, and the symptoms were altered sensorium, headache, fever and stiff neck. CONCLUSIONS: The high morbidity and mortality observed among patients with cryptococcosis demonstrate the importance of obtaining information regarding the epidemiological profile and clinical course of the disease in the State of Goiás, Brazil.


Assuntos
Cryptococcus neoformans/genética , Meningite Criptocócica/microbiologia , Adulto , Brasil/epidemiologia , Cryptococcus neoformans/isolamento & purificação , Impressões Digitais de DNA , DNA Bacteriano/genética , Feminino , Humanos , Masculino , Meningite Criptocócica/mortalidade , Pessoa de Meia-Idade , Tipagem Molecular , Estudos Prospectivos , Adulto Jovem
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