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1.
Mycopathologia ; 189(1): 2, 2024 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-38217794

RESUMO

Trichophyton species cause dermatophytosis in humans, with a high, worldwide frequency of reports and important public health relevance. We evaluated 61 Trichophyton strains from different sources deposited in the University Recife Mycology (URM) culture collection of the Universidade Federal de Pernambuco, Brazil. Strains were phenotypically identified and confirmed by sequencing Internal Transcribed Spacers rDNA and partial beta-tubulin 2-exon. Additionally, we evaluated their susceptibility to terbinafine and itraconazole. Physiological analyses included urease activity and growth in casein medium. Phenotypic methods allowed the reliable identification of T. rubrum only, whereas, for other species, molecular methods were mandatory. All Trichophyton species exhibited susceptibility profiles to itraconazole (0.04-5.33 µg/mL) and terbinafine (0.17-3.33 µg/mL). Our analyses revealed a heterogeneous distribution of T. mentagrophytes, which does not support the current distribution within the species complex of T. mentagrophytes and its genotypes.


Assuntos
Arthrodermataceae , Tinha , Humanos , Trichophyton , Terbinafina/farmacologia , Antifúngicos/farmacologia , Itraconazol , Brasil , Universidades , Testes de Sensibilidade Microbiana , Arthrodermataceae/genética
2.
Mycopathologia ; 185(2): 395-398, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31897974

RESUMO

Emergent fungal infections are uncommon conditions which frequently lead to death. To our knowledge, only a few cases of invasive infection by Cystobasidium minutum (previously known as Rhodotorula minuta) have been reported. Moreover, several factors are responsible for deep site infections, such as catheter-related fungemia. This report describes the first case report of Cystobasidium minutum causing fungemia in Brazil. The pathogens fungemia was demonstrated by catheter and blood culture-proven, and both yeasts were identified by sequences of D1/D2 rDNA region. After the end of antifungal therapy and catheter removal, a second blood culture was found to be negative and the clinical signs and symptoms of the patient improved.


Assuntos
Basidiomycota/isolamento & purificação , Fungemia , Neoplasias/complicações , Anfotericina B/administração & dosagem , Anfotericina B/uso terapêutico , Antifúngicos/uso terapêutico , Basidiomycota/classificação , Basidiomycota/genética , Brasil , Infecções Relacionadas a Cateter/microbiologia , DNA Fúngico , DNA Ribossômico , Ácido Desoxicólico/administração & dosagem , Ácido Desoxicólico/uso terapêutico , Combinação de Medicamentos , Feminino , Fungemia/tratamento farmacológico , Fungemia/patologia , Humanos , Hospedeiro Imunocomprometido , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Neutropenia
3.
Exp Dermatol ; 25(1): 79-81, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26476093

RESUMO

White piedra is a fungal infection characterized by nodules comprised of Trichosporon species and restricted to the extrafollicular portion of the hair shaft. The diagnosis is based on clinical and mycological characteristics, and must be confirmed with a precise identification of the etiological agent. This research aimed to develop an in vitro infection model of white piedra and analyze its morphological and ultra-structural aspects. In the process, hair infection was induced using eight isolates of the genus Trichosporon maintained in the Culture Collection Micoteca URM. The ITS and IGS1 regions were sequenced for taxonomic confirmation. Scanning Electron Microscope (SEM) was performed at the Strategic Center for Northeast Technologies (CETENE). The scanning electron microscope was equipped with an Energy Dispersion Spectrometer (EDS). The Trichosporon isolates were identified as Trichosporon asahii (6) and Trichosporon montevideense (2) by internal transcript spacer (ITS) region and intergenic spacer 1 region (IGS1) sequencing. All eight strains were used to induce the in vitro hair infection, and nodules formed after the incubation period. Temperature variations and high humidity were not observed to be related to the development of this hair disease. The main chemical constituents detected in the nodules were carbon, nitrogen and oxygen, as well as a low level of sulfur. The absence of calcium, combined with the low level of sulfur, might explain the soft nature of the white piedra nodules. This study demonstrated that several Trichosporon species may be responsible for causing white piedra.


Assuntos
Doenças do Cabelo/microbiologia , Microscopia Eletrônica de Varredura , Piedra/diagnóstico , Piedra/microbiologia , Cálcio/química , Cabelo/ultraestrutura , Humanos , Nitrogênio/química , Oxigênio/química , Enxofre/química , Trichosporon
4.
Mycopathologia ; 180(1-2): 69-73, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25666389

RESUMO

Candidemia is a frequent condition in Neonatal Intensive Care Units (NICU) and usually complicates the newborns clinical course. Several factors are responsible for candidiasis, such as prematurity and use of broad-spectrum antibiotics, and in these cases, there are the involvement of various Candida species, as C. albicans, and C. parapsilosis. However, other species as C. haemulonii has been rarely described in candidemia cases, being considered an emergent pathogen. Thus, we report a case of neonatal candidemia by C. haemulonii and a review of literature of fungemia by this yeast. The patient was a neonate with gestational age of 26 weeks and birth weight of 660 g hospitalized in a NICU from a Brazilian hospital. The identification of the etiological agent was performed by phenotypic methods, scanning electron microscopy, sequencing of the ITS region of rDNA, and mass spectrometry. Antifungal susceptibility testing was carried out according to the Clinical Laboratories and Standards Institute guidelines. The newborn was diagnosed with candidemia by C. haemulonii resistant to amphotericin B with minimal inhibitory concentration (MIC) of 8 µg/mL, sensitive to fluconazole (MIC: 8 µg/mL) and voriconazole (MIC: 0.12 µg/mL). The treatment with fluconazole (12 mg/kg/day) was established with good outcome. Candidemia by C. haemulonii is still being limited to a few sporadic cases in adults with endemic and restricted occurrences in neonates. Usually, the therapy with amphotericin B is ineffective against this species. Our results showed the importance of the mycological diagnosis associated to antifungigrama for the successful clinical management followed by important epidemiological data.


Assuntos
Candida/isolamento & purificação , Candidemia/diagnóstico , Candidemia/microbiologia , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Brasil , Candida/classificação , Candida/genética , Candida/fisiologia , Candidemia/tratamento farmacológico , DNA Fúngico/química , DNA Fúngico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Farmacorresistência Fúngica , Feminino , Humanos , Recém-Nascido de Peso Extremamente Baixo ao Nascer , Recém-Nascido , Espectrometria de Massas , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Análise de Sequência de DNA , Resultado do Tratamento
6.
Sci Rep ; 14(1): 956, 2024 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-38200060

RESUMO

The timely and accurate diagnosis of candidemia, a severe bloodstream infection caused by Candida spp., remains challenging in clinical practice. Blood culture, the current gold standard technique, suffers from lengthy turnaround times and limited sensitivity. To address these limitations, we propose a novel approach utilizing an Electronic Nose (E-nose) combined with Time Series-based classification techniques to analyze and identify Candida spp. rapidly, using culture species of C. albicans, C.kodamaea ohmeri, C. glabrara, C. haemulonii, C. parapsilosis and C. krusei as control samples. This innovative method not only enhances diagnostic accuracy and reduces decision time for healthcare professionals in selecting appropriate treatments but also offers the potential for expanded usage and cost reduction due to the E-nose's low production costs. Our proof-of-concept experimental results, carried out with culture samples, demonstrate promising outcomes, with the Inception Time classifier achieving an impressive average accuracy of 97.46% during the test phase. This paper presents a groundbreaking advancement in the field, empowering medical practitioners with an efficient and reliable tool for early and precise identification of candidemia, ultimately leading to improved patient outcomes.


Assuntos
Candida , Candidemia , Pichia , Humanos , Inteligência Artificial , Nariz Eletrônico , Candida parapsilosis
7.
Future Microbiol ; 18: 1225-1233, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37882752

RESUMO

Aim: To evaluate antifungal potential of 5,6,7,8-tetrahydroimidazo[1,2-a]pyrazine hybrids based on thiosemicarbazones and thiazolidinediones against pathogenic Sporothrix species. Methods: Antifungal activity of nine compounds were assessed by broth microdilution. Interactions between active compounds and itraconazole were evaluated by the checkerboard assay using non-wild-type isolates. Cytotoxicity of the compounds was determined. Results: Four C-3 substituted analogs showed antifungal activity, unrelated to thiosemicarbazone or thiazolidinedione functions. Synergistic interactions between the four compounds and itraconazole, and low toxicity on mouse fibroblast cells were observed. Activity of 5,6,7,8-tetrahydroimidazo[1,2-a]pyrazine hybrids against Sporothrix depended on the substitution on the imidazopyrazine ring. Conclusion: Antifungal potential, overcoming itraconazole resistance and low toxicity indicate the possible use of that series of compounds in a therapeutic alternative for treatment of sporotrichosis.


Assuntos
Sporothrix , Tiazolidinedionas , Tiossemicarbazonas , Animais , Camundongos , Antifúngicos/farmacologia , Itraconazol/farmacologia , Tiossemicarbazonas/farmacologia , Testes de Sensibilidade Microbiana
8.
Med Mycol ; 50(7): 756-9, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22103341

RESUMO

The aim of this study was to evaluate, through lectin histochemistry, the expression of N-acetyl-D-glucosamine, L-fucose, D-galactose and glucose/mannose on the cell wall surfaces of Aspergillus species in histopathological specimens of brain (n = 1) and lung (n = 6) tissues obtained during autopsy of patients diagnosed postmortem as having had invasive aspergillosis. Concanavalin A (Con A), wheat germ agglutinin (WGA), Ulex europeus agglutinin I (UEA-I) and peanut agglutinin (PNA), all conjugated with horseradish peroxidase, were employed. Lectin-binding was visualized using 3,3-diaminobendizine (DAB) and hydrogen peroxide in phosphate buffer solution (PBS). We observed expression of N-acetyl-D-glucosamine and methyl-α-D-mannoside on the cell wall surfaces of all evaluated Aspergillus species, while the expression of L-fucose and D-galactose demonstrated inter and intra-specific variations. The results obtained from this study indicate that the use of WGA and Con A lectins permits visualization of Aspergillus structures such as hyphae, conidial heads and conidia in histopathological specimens of brain and lung tissues.


Assuntos
Aspergilose/microbiologia , Aspergillus/química , Carboidratos/análise , Parede Celular/química , Glicoconjugados/análise , Lectinas , Idoso , Idoso de 80 Anos ou mais , Aspergillus/isolamento & purificação , Autopsia , Encéfalo/microbiologia , Feminino , Histocitoquímica/métodos , Humanos , Pulmão/microbiologia , Masculino , Pessoa de Meia-Idade , Micologia/métodos
9.
Molecules ; 17(5): 5882-92, 2012 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-22592091

RESUMO

1,2,3-Triazoles have been extensively studied as compounds possessing important biological activities. In this work, we describe the synthesis of ten 2-(1-aryl-1H-1,2,3-triazol-4-yl)propan-2-ols via copper catalyzed azide alkyne cycloaddition (CuAAc or click chemistry). Next the in vitro antifungal activity of these ten compounds was evaluated using the microdilution broth method against 42 isolates of four different Candida species. Among all tested compounds, the halogen substituted triazole 2-[1-(4-chlorophenyl)-1H-(1,2,3)triazol-4-yl]propan-2-ol, revealed the best antifungal profile, showing that further modifications could be done in the structure to obtain a better drug candidate in the future.


Assuntos
Antifúngicos/síntese química , Candida/efeitos dos fármacos , Propanóis/síntese química , Triazóis/síntese química , Animais , Antifúngicos/farmacologia , Azidas/química , Candida/crescimento & desenvolvimento , Química Click , Desenho de Fármacos , Masculino , Miconazol/farmacologia , Testes de Sensibilidade Microbiana , Propanóis/farmacologia , Ratos , Ratos Wistar , Relação Estrutura-Atividade , Triazóis/farmacologia
10.
Future Microbiol ; 17: 903-915, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35748170

RESUMO

Candida nivariensis caused refractory esophagitis in a 36-year-old Brazilian man coinfected with HIV and Leishmania. A literature review on this rare fungal pathogen is also presented. The diagnosis was made, and pathogen identification was performed using matrix-assisted laser desorption ionization-time of flight mass spectrometry and sequencing of the LSU/26S region. An antifungigram was performed using broth microdilution. A literature search of PubMed was performed. The causative agent, C. nivariensis, was resistant to fluconazole and voriconazole. The patient's condition worsened considerably, and he passed away. This is the second report of this Candida species in Brazil and the first case reported worldwide of refractory esophagitis in a patient coinfected with HIV and Leishmania. The case illustrates the importance of precise identification and antifungal susceptibility testing when isolating this emerging pathogen.


Assuntos
Esofagite , Infecções por HIV , Adulto , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Brasil , Farmacorresistência Fúngica , Esofagite/diagnóstico , Esofagite/tratamento farmacológico , Fluconazol/farmacologia , Fluconazol/uso terapêutico , Infecções por HIV/tratamento farmacológico , Humanos , Masculino , Testes de Sensibilidade Microbiana , Saccharomyces cerevisiae , Saccharomycetales
11.
Future Microbiol ; 17: 1437-1443, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36382573

RESUMO

Two cases of otomycosis have been reported in patients undergoing tympanomastoidectomy. The first one had chronic otitis media, hypertrophic concha and nasal septum deviation, tympanic perforation and otorrhea. The second had otalgia, pruritus, chronic otitis media and cholesteatoma. Direct examination showed mycelial septate filaments with a branch at an angle close to 45°, later identified as Aspergillus sydowii by sequencing the BenA and CaM genes. Susceptibility testing showed low MIC of amphotericin B, itraconazole, ketoconazole and ciclopirox olamine. In both cases, ketoconazole was instituted for 10 days. Otomycosis is a challenge as it is primarily recurrent in patients undergoing surgery. The clinical implication, the identification of the emerging pathogen and the determination of MIC were necessary for the knowledge of the epidemiological profile and establishment of the treatment.


Aspergillus are fungi that can cause ear disease. In severe infections, these fungi can be present for long periods inside the ear, and commonly belong to the species Aspergillus section Nigri and Aspergillus flavus. In this work, we present two cases of ear infections by a different species, Aspergillus sydowii. Patients had obstructed nasal cavities, crooked internal separation of the nose and complaints of secretion in the ear. The efficient diagnosis allowed a treatment that resulted in the death of the fungus and the cure of the patient.


Assuntos
Otomicose , Humanos , Otomicose/diagnóstico , Otomicose/tratamento farmacológico , Cetoconazol/uso terapêutico , Aspergillus/genética , Itraconazol/uso terapêutico , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico
12.
J Mycol Med ; 32(1): 101213, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34758424

RESUMO

Mycobacterium tuberculosis, which is responsible for tuberculosis (TB) and Cryptococcus sp. responsible for cryptococcosis, are pathogenic microorganisms that especially affect patients infected with the human immunodeficiency virus (HIV). Both diseases present similar classic symptoms, which makes diagnosis and treatment consequently difficult. To our knowledge, a few reported cases of M. tuberculosis and Cryptococcus sp. co-infection in non-HIV patients exist. This study reports a TB and neurocryptococcosis (NC) comorbidity case in a patient who had no clinical or serological evidence of HIV-compromised immunity. A 49-year-old male patient, a farmer with a low education level, previously diagnosed with TB and was undergoing treatment for a month when he presented progressive headaches, fever, drowsiness and photosensitivity, a stiff neck and a positive Lasègue test. During hospitalization, the patient was also diagnosed with NC through cerebrospinal fluid (CSF) analysis, which revealed the presence of capsulated yeasts by contrast with india ink. Following the yeast isolation, proteomic and molecular analyzes were performed. The patient received antifungal therapy in parallel with TB treatment, which caused complications and had to be modified twice. However, after three months of hospitalization the patient was discharged. Tuberculosis and cryptococcosis co-infection is a clinical and laboratory challenge, often leading to a delay in diagnosis. In this paper we emphasize the need to understand these infectious comorbidities in non-HIV patients from South America, since the few cases reported in the literature are from studies conducted in the United States and China.


Assuntos
Criptococose , Cryptococcus neoformans , Infecções por HIV , Tuberculose , Comorbidade , Criptococose/diagnóstico , Criptococose/tratamento farmacológico , Criptococose/epidemiologia , Cryptococcus neoformans/genética , Infecções por HIV/microbiologia , Humanos , Masculino , Pessoa de Meia-Idade , Proteômica , Tuberculose/complicações
13.
Future Microbiol ; 17: 81-87, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34913372

RESUMO

Trichosporon species are emerging as opportunistic pathogens that mainly affect immunocompromised patients. Patients with onco-hematological diseases usually present with fungemia by Trichosporon species, especially by T. asahii. Reports of this infection by other species of the genus are uncommon. Thus, in this paper, we present a case of T. inkin fungemia in a 39-year-old female patient with intestinal obstruction and absence of malignant hematological diseases. The late mycological diagnosis, the ineffective control of her pre-existing conditions and consequent failure to start antifungal therapy were the contributing factors for the patient's death.


Lay abstract Trichosporon species have been emerged as opportunistic fungi that mainly affect patients with low immunity. Hematological (blood related) cancer patients usually present with bloodstream infection with Trichosporon species, particularly Trichosporon asahii. Reports of this infection by other species of the genus are uncommon. Thus, in this paper, we present a case of bloodstream infection by Trichosporon inkin in a 39-year-old female patient with intestinal obstruction and absence of hematological cancer. The late fungal diagnosis, the ineffective control of the first symptoms and consequent failure to start specific medication were the factors that led to the patient's death.


Assuntos
Basidiomycota , Fungemia , Trichosporon , Adulto , Antifúngicos/uso terapêutico , Feminino , Fungemia/diagnóstico , Fungemia/tratamento farmacológico , Humanos
14.
Mycoses ; 54(1): 23-9, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19735440

RESUMO

Many studies have described the adherence of Candida albicans to epithelial cells but little is known about Candida parapsilosis adhesion and its role in host cell surface recognition. This study was designed to evaluate the correlation between the adherence of 20 C. albicans and 12 C. parapsilosis strains to human buccal epithelial cells and the expression of fungal cell surface carbohydrates using lectin histochemistry. Adherence assays were carried out by incubating epithelial cells in yeast suspensions (10(7) cells ml(-1) ) and peroxidase conjugated lectins (Con A, WGA, UEA I and PNA at 25 µg ml(-1) ) were used for lectin histochemistry. The results showed that adherence was overall greater for C. albicans than for C. parapsilosis (P < 0.01) and that the individual strain differences correlated with a high content of cell surface α-l-fucose residues as indicated by the UEA I staining pattern. Based on the saccharide specificity of the lectins used, these results suggest that l-fucose residues on cell surface glycoconjugates may represent recognition molecules for interactions between the yeast strain studied and the host (r = 0.6985, P = 0.0045). In addition, our results indicated the presence of α-d-glucose/α-d-mannose, N-acetyl-D-glucosamine/N-acetylneuraminic acid and D-galactose/N-acetyl-D-galactosamine in fungal cell wall.


Assuntos
Candida albicans/fisiologia , Candida/fisiologia , Candidíase/microbiologia , Metabolismo dos Carboidratos , Parede Celular/metabolismo , Células Epiteliais/microbiologia , Candida/genética , Candida albicans/genética , Parede Celular/genética , Células Cultivadas , Humanos , Mucosa Bucal/microbiologia
15.
Future Microbiol ; 16: 1371-1379, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34812048

RESUMO

Aim: Cases of sporotrichosis are emerging in several states of Brazil, especially in the southeast. Recently, sporotrichosis has been reported in the state of Pernambuco in the northeastern region. The goal of this study was to shed new light on sporotrichosis in terms of the geographic distribution of human cases and provide an overview of sporotrichosis associated with zoonotic transmission. Patients & methods: From March 2017 to November 2019, 179 patients were diagnosed with sporotrichosis. Georeferencing analysis, spatial distribution and epidemiological features of all cases are described. Results: The data show the dynamics of accelerated transmission of sporotrichosis across urban and coastal areas of the state of Pernambuco. Conclusion: There is a need to decentralize health services and implement a One Health approach to this emerging disease.


Assuntos
Sporothrix , Esporotricose , Brasil/epidemiologia , Humanos , Esporotricose/epidemiologia
16.
Med Mycol ; 48(6): 862-5, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20144130

RESUMO

Diabetic patients are at risk of acquiring esophageal infections such as those caused by members of the genus Candida. Here we describe a case in which Candida guilliermondii was isolated from the esophageal mucosa of a patient with uncontrolled diabetes mellitus. Due to inappropriate and inaccurate identification, the emergence of non-C. albicans Candida species as potential pathogens has been underestimated. This should be a cause of concern since C. guilliermondii is a normal component of human microbiota. The identity of the isolate in our case was confirmed by its characteristic morphophysiological features and amplification of rDNA using species-specific primers. Fluconazole therapy produced no improvement of the esophageal symptoms, and resistance of the etiologic agent was confirmed through in vitro susceptibility tests. This is thought to be the first documented case of C. guilliermondii esophagitis in a patient with diabetes mellitus.


Assuntos
Candida/isolamento & purificação , Candidíase/diagnóstico , Candidíase/patologia , Complicações do Diabetes/diagnóstico , Complicações do Diabetes/patologia , Esofagite/diagnóstico , Esofagite/patologia , Antifúngicos/uso terapêutico , Candida/classificação , Candida/citologia , Candida/genética , Candidíase/tratamento farmacológico , Candidíase/microbiologia , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Complicações do Diabetes/tratamento farmacológico , Complicações do Diabetes/microbiologia , Esofagite/tratamento farmacológico , Esofagite/microbiologia , Feminino , Fluconazol/uso terapêutico , Humanos , Testes de Sensibilidade Microbiana , Microscopia , Pessoa de Meia-Idade , Mucosa/microbiologia , Técnicas de Tipagem Micológica , Análise de Sequência de DNA
17.
Microorganisms ; 8(1)2020 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-31940988

RESUMO

Mass spectrometry by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) was used to identify and differentiate the pattern of susceptibility of clinical isolates of Candida parapsilosis complex. 17 C. parapsilosis sensu stricto, 2 C. orthopsilosis, and 1 C. metapsilosis strains were obtained from blood cultures, and three different inocula (103, 105, and 107 CFU/mL) were evaluated against three echinocandins at concentrations ranging from 0.03 to 16 µg/mL after incubation of 1 h, 2 h, and 3 h. Drug-free control was used. The spectra obtained at these concentrations were applied to generate composite correlation index (CCI) matrices for each yeast individually. After cross correlations and autocorrelations of each spectra with null (zero) and maximal (16) concentrations, the CCI was used as separation parameter among spectra. Incubation time and inoculum were critical factors to reach higher precision and reliability of this trial. With an incubation time of 3 h and inoculum of 107 CFU/mL, it was possible to determine the breakpoint of the clinical yeasts by MALDI-TOF that presented high agreement with the clinical laboratory standard institute (CLSI) reference method. Herein, we show that mass spectrometry using the MALDI-TOF technique is powerful when it exploits antifungal susceptibility testing assays.

18.
Microbiol Res ; 230: 126330, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31541842

RESUMO

Glycoconjugates found on cell walls of Candida species are fundamental for their pathogenicity. Laborious techniques have been employed to investigate the sugar composition of these microorganisms. Herein, we prepared a nanotool, based on the fluorescence of quantum dots (QDs) combined with the specificity of Cramoll lectin, to evaluate glucose/mannose profiles on three Candida species. The QDs-Cramoll conjugates presented specificity and bright fluorescence emission. The lectin preserved its biological activity after the conjugation process mediated by adsorption interactions. The labeling of Candida species was analyzed by fluorescence microscopy and quantified by flow cytometry. Morphological analyses of yeasts labeled with QDs-Cramoll conjugates indicated that C. glabrata (2.7 µm) was smaller when compared to C. albicans (4.0 µm) and C. parapsilosis sensu stricto (3.8 µm). Also, C. parapsilosis population was heterogeneous, presenting rod-shaped blastoconidia. More than 90% of cells of the three species were labeled by conjugates. Inhibition and saturation assays indicated that C. parapsilosis had a higher content of exposed glucose/mannose than the other two species. Therefore, QDs-Cramoll conjugates demonstrated to be effective fluorescent nanoprobes for evaluation of glucose/mannose constitution on the cell walls of fungal species frequently involved in candidiasis.


Assuntos
Candida/química , Corantes Fluorescentes/química , Glucose/análise , Lectinas/química , Manose/análise , Microscopia de Fluorescência/métodos , Candida/crescimento & desenvolvimento , Candida/isolamento & purificação , Candida/metabolismo , Candidíase/diagnóstico , Candidíase/microbiologia , Parede Celular/química , Parede Celular/metabolismo , Glucose/metabolismo , Humanos , Manose/metabolismo , Microscopia de Fluorescência/instrumentação , Nanopartículas/química , Pontos Quânticos/química
19.
Comp Immunol Microbiol Infect Dis ; 65: 226-233, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31300118

RESUMO

The aim of this study is to verify the action of the aqueous leaf extract Ziziphus joazeiro in the eradication of bacterial and fungal biofilms, and to compare these effects with the stem bark extracts, as well as with conventional standard drugs. The presence of secondary metabolites was observed through phytochemical prospection assays. The effect of the aqueous extract on microbial biofilm formation was observed by OD600 nm absorbance and the crystal violet assay. For bacterial and fungal biofilms, chlorhexidine gluconate and fluconazole, respectively, were used as positive controls. Phytochemical characterization showed the presence of secondary metabolite classes common to both extracts such as flavonoids, steroids and saponins. In particular, in the aqueous leaf extract phenols, condensed tannins and alkaloids were observed. Eradication results using the aqueous leaf extract showed an inhibition of the microbial biofilm mass, moreover the biofilms were more sensitive to the bark extract, which presented a greater inhibition number and an action similar to standard drugs. It is important to highlight the leaf extract showed significant eradication at the lowest concentrations for mature yeast biofilms, thus demonstrating its potential to modify microbial resistance susceptibility. Bacterial and fungal biofilm eradication results using the Ziziphus joazeiro aqueous extracts presented a biofilm inhibition effect for both, moreover the results support the ethnopharmacological knowledge surrounding the use of Ziziphus joazeiro stems in the community. In comparison, the bark extract presented a more effective treatment than the leaf extract against biofilms, presenting inhibition levels similar to the used standard drugs.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Bactérias/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Fungos/efeitos dos fármacos , Extratos Vegetais/farmacologia , Ziziphus/química , Antibacterianos/química , Antifúngicos/química , Clorexidina/análogos & derivados , Clorexidina/farmacologia , Fluconazol/farmacologia , Testes de Sensibilidade Microbiana , Casca de Planta/química , Extratos Vegetais/química , Folhas de Planta/química
20.
Front Microbiol ; 7: 1783, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27895625

RESUMO

Several studies have been developed regarding human health risks associated with the recreational use of beaches contaminated with domestic sewage. These wastes contain various micro-organisms, including Candida tropicalis. In this context, the objective of this study was to characterize C. tropicalis isolates from the sandy beach of Ponta Negra, Natal, Rio Grande do Norte, Brazil, regarding the expression of in vitro virulence factors, adaptation to osmotic stress and susceptibility to antifungal drugs. We analyzed 62 environmental isolates and observed a great variation among them for the various virulence factors evaluated. In general, environmental isolates were more adherent to human buccal epithelial cells (HBEC) than C. tropicalis ATCC13803 reference strain, and they also showed increased biofilm production. Most of the isolates presented wrinkled phenotypes on Spider medium (34 isolates, 54.8%). The majority of the isolates also showed higher proteinase production than control strains, but low phospholipase activity. In addition, 35 isolates (56.4%) had high hemolytic activity (hemolysis index > 0.55). With regard to C. tropicalis resistance to osmotic stress, 85.4% of the isolates were able to grow in a liquid medium containing 15% sodium chloride. The strains were highly resistant to the azoles tested (fluconazole, voriconazole and itraconazole). Fifteen strains were resistant to the three azoles tested (24.2%). Some strains were also resistant to amphotericin B (14 isolates; 22.6%), while all of them were susceptible for the echinocandins tested, except for a single strain of intermediate susceptibility to micafungin. Our results demonstrate that C. tropicalis isolated from the sand can fully express virulence attributes and showed a high persistence capacity on the coastal environment; in addition of showing high minimal inhibitory concentrations to several antifungal drugs used in current clinical practice, demonstrating that environmental isolates may have pathogenic potential.

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