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Cryptococcus gattii, an environmental fungus, is one of the agents of cryptococcosis. The influence of agrochemicals on fungal resistance to antifungals is widely discussed. However, the effects of benomyl (BEN) on fungal interaction with different hosts is still to be understood. Here we studied the influence of adaptation to BEN in the interaction with a plant model, phagocytes and with Tenebrio molitor. First, the strain C. gattii L24/01 non-adapted (NA), adapted (A) to BEN, and adapted with further culture on drug-free media (10p) interact with Nicotiana benthamiana, with a peak in the yeast burden on the 7th day post-inoculation. C. gattii L24/01 A and 10p provided lower fungal burden, but these strains increased cell diameter and capsular thickness after the interaction, together with decreased fungal growth. The strains NA and A showed reduced ergosterol levels, while 10p exhibited increased activity of laccase and urease. L24/01 A recovered from N. benthamiana was less engulfed by murine macrophages, with lower production of reactive oxygen species. This phenotype was accompanied by increased ability of this strain to grow inside macrophages. Otherwise, L24/01 A showed reduced virulence in the T. molitor larvae model. Here, we demonstrate that the exposure to BEN, and interaction with plants interfere in the morphophysiology and virulence of the C. gattii.
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Cryptococcus gattii , Nicotiana , Cryptococcus gattii/efeitos dos fármacos , Cryptococcus gattii/crescimento & desenvolvimento , Cryptococcus gattii/metabolismo , Cryptococcus gattii/fisiologia , Animais , Camundongos , Nicotiana/microbiologia , Macrófagos/microbiologia , Criptococose/microbiologia , Tenebrio/microbiologia , Agroquímicos/farmacologia , Antifúngicos/farmacologia , Doenças das Plantas/microbiologiaRESUMO
BACKGROUND: Cryptococcosis is a life-threatening disease caused by Cryptococcus neoformans or C. gattii. Neutralizing autoantibodies (auto-Abs) against granulocyte-macrophage colony-stimulating factor (GM-CSF) in otherwise healthy adults with cryptococcal meningitis have been described since 2013. We searched for neutralizing auto-Abs in sera collected from Colombian patients with non-HIV-associated cryptococcosis in a retrospective national cohort from 1997 to 2016. METHODS: We reviewed clinical and laboratory records and assessed the presence of neutralizing auto-Abs against GM-CSF in 30 HIV negative adults with cryptococcosis (13 caused by C. gattii and 17 caused by C. neoformans). RESULTS: We detected neutralizing auto-Abs against GM-CSF in the sera of 10 out of 13 (77%) patients infected with C. gattii and one out of 17 (6%) patients infected with C. neoformans. CONCLUSIONS: We report eleven Colombian patients diagnosed with cryptococcosis who had auto-Abs that neutralize GM-CSF. Among these patients, ten were infected with C. gattii and only one with C. neoformans.
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Anticorpos Neutralizantes , Autoanticorpos , Criptococose , Cryptococcus gattii , Cryptococcus neoformans , Fator Estimulador de Colônias de Granulócitos e Macrófagos , Humanos , Fator Estimulador de Colônias de Granulócitos e Macrófagos/imunologia , Autoanticorpos/sangue , Autoanticorpos/imunologia , Masculino , Colômbia , Feminino , Adulto , Cryptococcus gattii/imunologia , Pessoa de Meia-Idade , Cryptococcus neoformans/imunologia , Criptococose/imunologia , Criptococose/diagnóstico , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Estudos Retrospectivos , Soronegatividade para HIV/imunologia , Adulto Jovem , IdosoRESUMO
The development of technologies that allow the production of enzymes at a competitive cost is of great importance for several biotechnological applications, and the use of agro-industrial by-products is an excellent alternative to minimize costs and reduce environmental impacts. This study aimed to produce endo-xylanases using agro-industrial substrates rich in hemicellulose as sources of xylan in culture media. For this purpose, the yeast Cryptococcus laurentti and five lignocellulosic materials (defatted rice bran, rice husk, corn cob, oat husks, and soybean tegument), with and without pretreatment, were used as a source of xylan for enzyme production. To insert the by-products in the culture medium, they were dried and treated (if applicable) with 4% (w.v-1) NaOH and then added in a concentration of 2% (w.v-1). The cultures were agitated for 96 h, and the aliquots were removed to determine the enzymatic activities. Among the by-products studied, the maximum activity (8.7 U. mL-1 at pH 7.3) was obtained where rice bran was used. In contrast, corn cob was the by-product that resulted in lower enzyme production (1.6 U.mL-1). Thus, the defatted rice bran deserves special attention in front of the other by-products used since it provides the necessary substrate for producing endo-xylanases by yeast.
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Cryptococcus neoformans causes cryptococcosis, one of the most prevalent fungal diseases, generally characterized by meningitis. There is a limited and not very effective number of drugs available to combat this disease. In this manuscript, we show the host defense peptide mimetic brilacidin (BRI) as a promising antifungal drug against C. neoformans. BRI can affect the organization of the cell membrane, increasing the fungal cell permeability. We also investigated the effects of BRI against the model system Saccharomyces cerevisiae by analyzing libraries of mutants grown in the presence of BRI. In S. cerevisiae, BRI also affects the cell membrane organization, but in addition the cell wall integrity pathway and calcium metabolism. In vivo experiments show BRI significantly reduces C. neoformans survival inside macrophages and partially clears C. neoformans lung infection in an immunocompetent murine model of invasive pulmonary cryptococcosis. We also observed that BRI interacts with caspofungin (CAS) and amphotericin (AmB), potentiating their mechanism of action against C. neoformans. BRI + CAS affects endocytic movement, calcineurin, and mitogen-activated protein kinases. Our results indicate that BRI is a novel antifungal drug against cryptococcosis. IMPORTANCE: Invasive fungal infections have a high mortality rate causing more deaths annually than tuberculosis or malaria. Cryptococcosis, one of the most prevalent fungal diseases, is generally characterized by meningitis and is mainly caused by two closely related species of basidiomycetous yeasts, Cryptococcus neoformans and Cryptococcus gattii. There are few therapeutic options for treating cryptococcosis, and searching for new antifungal agents against this disease is very important. Here, we present brilacidin (BRI) as a potential antifungal agent against C. neoformans. BRI is a small molecule host defense peptide mimetic that has previously exhibited broad-spectrum immunomodulatory/anti-inflammatory activity against bacteria and viruses. BRI alone was shown to inhibit the growth of C. neoformans, acting as a fungicidal drug, but surprisingly also potentiated the activity of caspofungin (CAS) against this species. We investigated the mechanism of action of BRI and BRI + CAS against C. neoformans. We propose BRI as a new antifungal agent against cryptococcosis.
Assuntos
Antifúngicos , Criptococose , Cryptococcus neoformans , Saccharomyces cerevisiae , Antifúngicos/farmacologia , Cryptococcus neoformans/efeitos dos fármacos , Animais , Camundongos , Criptococose/tratamento farmacológico , Criptococose/microbiologia , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/genética , Modelos Animais de Doenças , Macrófagos/microbiologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Testes de Sensibilidade Microbiana , Caspofungina/farmacologia , Feminino , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Anfotericina B/farmacologiaRESUMO
Resumen Introducción : La criptococosis meníngea (CM) es una causa frecuente de meningoencefalitis en personas que viven con HIV (PVHIV) y produce una importante morbi-mortalidad (20-55%). Se describen las características clínicas, la letalidad y las variables de mal pronóstico en PVHIV con CM, en unidades de cuidados intensivos (UCI). Métodos : Estudio observacional y retrospectivo. Pe ríodo 21/11/2006 a 24/05/2023. Población evaluada: 154 PVHIV adultos, admitidos en UCI con diagnóstico de CM. Los porcentajes y valores absolutos, fueron comparados mediante Chi-Cuadrado o test de Fisher y las medianas mediante test de Mann-Whitney. La asociación con mortalidad se evaluó por regresión logística. Se utilizó el programa SPSS 23.0. Un valor p<0.05 fue considerado significativo. Resultados : Los pacientes que fallecieron y los que so brevivieron fueron comparables en edad y sexo (p>0.05). El análisis univariado, observó que un estado funcional y nutricional alterado, falta de tratamiento antirretroviral previo (TARV), CD4 <100 células/μl, APACHE II ≥13 y un score pronóstico de PVHIV ≥8 puntos, requerir ventilación mecánica (VM), sufrir insuficiencia respiratoria, renal, disfunción neurológica o sepsis, podrían estar asociados (p<0.05) con mortalidad. La regresión logística estableció que un estado funcional y nutricional alterado, un score pronóstico PVHIV ≥8, necesitar VM y sufrir sepsis serían variables independientes asociadas a mortalidad. Conclusión : Los resultados indican que el estado funcional y nutricional alterado, un score pronóstico PVHIV ≥8 puntos, requerir VM y sufrir sepsis al ingreso a UCI podrían servir como variables independientes para predecir un mayor riesgo de mortalidad.
Abstract Introduction : Meningeal cryptococcosis (MC) is a frequent cause of meningoencephalitis in people living with HIV (PLHIV), leading to substantial morbidity (20- 55%). Clinical characteristics, lethality and adverse prog nostic factors in PLHIV with MC admitted to intensive care units (ICUs) are described. Methods : A retrospective observational study. Period from 11/21/2006 to 05/24/2023. It involved 154 adult PLHIV diagnosed with MC and admitted to ICUs. Percen tages and absolute values were compared by Chi-Square or Fisher's test and medians by Mann-Whitney test. The association with mortality was assessed by logistic re gression. SPSS 23.0 software was used. A p-value <0.05 was considered significant. Results : Patients who died and those who survived were comparable in age and sex (p>0.05). Univariate analysis showed that impaired functional and nutritio nal status, lack of previous highly active antiretroviral therapy, CD4 <100 cells, APACHE II ≥13 and a PLHIV prognostic score ≥8 points, requiring mechanical venti lation (MV), respiratory failure, renal failure, neurological dysfunction or sepsis could be associated (p<0.05) with mortality. Logistic regression established that impaired functional and nutritional status, a PLHIV prognostic score ≥8, need for MV and presence of sepsis would be independent variables associated with mortality. Conclusion : The results indicate that altered functio nal and nutritional status, a PLHIV prognostic score ≥ 8 points, requiring MV and suffering sepsis on admission to the ICU are more frequent in deceased patients, and they could therefore serve as independent variables to predict a higher risk of mortality.
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Clinical and epidemiological features of 7 human immunodeficiency virus-negative Peruvian patients coinfected with human T-lymphotropic virus type 1 (HTLV-1) and cryptococcosis (2006-2017) were studied. Most cases had meningeal involvement, were male, and originated from Peru's jungle. Patients with cryptococcosis should be tested for HTLV-1 in endemic areas of this retrovirus.
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Aim: Cryptococcus gattii causes a severe fungal infection with high mortality rate among immunosuppressed and immunocompetent individuals. Due to limitation of current antifungal treatment, new immunotherapeutic approaches are explored.Methods: This study investigated an immunization strategy utilizing heat-inactivated C. gattii with ArtinM as an adjuvant. C57BL/6 mice were intranasally immunized with heat-killed C. gattii and ArtinM was administrated either before immunization or along with HK-C. gattii. Mice were infected with C. gattii and the efficacy of the immunization protocol was evaluated.Results: Mice that received ArtinM exhibited increased levels of IL-10 and relative expression of IL-23 in the lungs, reduced fungal burden and preserved tissue integrity post-infection.Conclusion: Adjuvant ArtinM improved immunization against C. gattii infection in C57BL/6 mice.
Cryptococcus gattii is a fungus that can make lungs sick. Right now, there are no good treatments for it, so scientists are trying to find new ways to fight it. In a recent study, they tested a type of immunotherapy called ArtinM to see if it could help. When they gave ArtinM to mice, the mice got healthier and had less fungus in their lungs. This means ArtinM might be able to help fight this fungus.
Assuntos
Adjuvantes Imunológicos , Criptococose , Cryptococcus gattii , Camundongos Endogâmicos C57BL , Animais , Cryptococcus gattii/imunologia , Camundongos , Criptococose/imunologia , Adjuvantes Imunológicos/administração & dosagem , Vacinas Fúngicas/imunologia , Modelos Animais de Doenças , Feminino , HumanosRESUMO
Cryptococcus neoformans is primarily responsible for cases of cryptococcal meningitis in individuals with HIV/AIDS. This study evaluated the susceptibility of C. neoformans obtained from individuals with cryptococcal meningitis associated with HIV/AIDS in Manaus, Amazonas, Brazil, against the action of the antifungals amphotericin B, flucytosine, fluconazole, itraconazole and posaconazole and analyzed it using Multilocus Sequence Typing (MLST) in order to identify the Sequence Types (STs). We analyzed 30 isolates of C. neoformans, from 24 HIV/AIDS patients diagnosed with cryptococcosis from 2017 to 2019 in a reference hospital, in addition to 3 environmental isolates: 1 isolate obtained in the home of a patient and 2 isolates obtained from neighboring homes of patients. 86.6% (n = 26/30) of the clinical isolates were identified as C. neoformans VNI ST93, 6.6% (n = 2/30) as C. neoformans VNI ST5, 3.3% (n = 1/30) as C. neoformans VNI ST32 and 3.3% (n = 1/30) as C. neoformans VNB ST232. The environmental isolates were identified as C. neoformans VNI ST93 (n = 3/3). 96.6% (n = 29/30) isolates were sensitive to amphotericin B, though there was variation in the MIC. 60% (n = 18/30) presented a MIC above the proposed epidemiological cutoff values for one or more antifungals. All environmental isolates were sensitive to the tested antifungals. The MLST showed that there is an important relationship between C. neoformans VNI ST93 and individuals with HIV/AIDS, including in the environmental isolates analyzed. C. neoformans VNB ST232 was observed for the first time in Amazonas. Amphotericin B was proven to be the best drug, but fluconazole and posaconazole also showed relevant action.
Assuntos
Antifúngicos , Cryptococcus neoformans , Infecções por HIV , Meningite Criptocócica , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Humanos , Cryptococcus neoformans/genética , Cryptococcus neoformans/efeitos dos fármacos , Cryptococcus neoformans/classificação , Cryptococcus neoformans/isolamento & purificação , Meningite Criptocócica/microbiologia , Brasil , Antifúngicos/farmacologia , Infecções por HIV/complicações , Infecções por HIV/virologia , Técnicas de Tipagem Micológica , Infecções Oportunistas Relacionadas com a AIDS/microbiologia , Masculino , Adulto , Feminino , Anfotericina B/farmacologiaRESUMO
This chapter describes methodological details for preparing specimens of Cryptococcus neoformans (although it can be applied to any species of the genus) and their subsequent analysis by scanning and transmission electron microscopy. Adaptations to conventional protocols for better preservation of the sample, as well as to avoid artifacts, are presented. The protocols may be used to examine both the surface ultrastructure and the interior of this pathogenic fungus in detail.
Assuntos
Artefatos , Cryptococcus neoformans , Cryptococcus neoformans/ultraestrutura , Microscopia Eletrônica de Transmissão/métodos , Microscopia Eletrônica de Varredura/métodos , Manejo de Espécimes/métodosRESUMO
The interaction between macrophages and Cryptococcus neoformans is crucial in the pathogenesis of cryptococcosis. These phagocytes are important immune effectors, but also a niche in which facultative intracellular parasites, such as C. neoformans, thrive. Consequently, phagocytosis of cryptococcal cells and its outcomes are very frequently studied. One major issue with several of the tests used for this, however, is that macrophage-C. neoformans interaction does not always result in phagocytosis, as fungi may be attached to the external surface of the phagocyte. The most used methodologies to study phagocytosis of cryptococcal cells have varying degrees of precision in separating fungi that are truly internalized from those that are outside macrophages. Here we describe two assays to measure phagocytosis that can differentiate internal from external C. neoformans cells.
Assuntos
Criptococose , Cryptococcus neoformans , Macrófagos , Fagocitose , Cryptococcus neoformans/imunologia , Macrófagos/microbiologia , Macrófagos/imunologia , Macrófagos/metabolismo , Criptococose/microbiologia , Criptococose/imunologia , Animais , Camundongos , Humanos , Interações Hospedeiro-Patógeno/imunologiaRESUMO
Melanin is a complex dark pigment synthetized by the phenoloxidase enzyme laccase in Cryptococcus neoformans. In vitro, this enzyme oxidizes exogenous catecholamines to produce melanin that may be secreted or incorporated into the fungal cell wall. This pigment has multiple roles in C. neoformans virulence during its interaction with different hosts and probably also in protecting fungal cells in the environment against predation and oxidative and radiation stresses, among others. However, it is important to note that laccase also has melanin-independent roles in C. neoformans interactions with host cells. In this chapter, we describe a quantitative laccase assay and a method for evaluating the kinetics of melanin production in C. neoformans colonies.
Assuntos
Cryptococcus neoformans , Lacase , Melaninas , Cryptococcus neoformans/metabolismo , Cryptococcus neoformans/enzimologia , Lacase/metabolismo , Melaninas/biossíntese , Melaninas/metabolismo , Ensaios Enzimáticos/métodosRESUMO
The importance of humoral immunity to fungal infections remains to be elucidated. In cryptococcosis, patients that fail to generate antibodies against antigens of the fungus Cryptococcus neoformans are more susceptible to the disease, demonstrating the importance of these molecules to the antifungal immune response. Historically, antibodies against C. neoformans have been applied in diagnosis, therapeutics, and as important research tools to elucidate fungal biology. Throughout the process of generating monoclonal antibodies (mAbs) from a single B-cell clone and targeting a single epitope, several immunization steps might be required for the detection of responsive antibodies to the antigen of interest in the serum. This complex mixture of antibodies comprises the polyclonal antibodies. To obtain mAbs, B-lymphocytes are harvested (from spleen or peripheral blood) and fused with tumor myeloma cells, to generate hybridomas that are individually cloned and specifically screened for mAb production. In this chapter, we describe all the necessary steps, from the immunization to polyclonal antibody harvesting, hybridoma generation, and mAb production and purification. Additionally, we discuss new cutting-edge approaches for generating interspecies mAbs, such as humanized mAbs, or for similar species in distinct host backgrounds.
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Anticorpos Antifúngicos , Anticorpos Monoclonais , Cryptococcus neoformans , Hibridomas , Cryptococcus neoformans/imunologia , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/isolamento & purificação , Animais , Humanos , Hibridomas/imunologia , Anticorpos Antifúngicos/imunologia , Anticorpos Antifúngicos/isolamento & purificação , Camundongos , Linfócitos B/imunologia , Criptococose/imunologia , Criptococose/diagnóstico , Antígenos de Fungos/imunologia , ImunizaçãoRESUMO
Extracellular vesicles (EVs) are produced by all domains of life. In fungal pathogens, they participate in virulence mechanisms and/or induce protective immunity, depending on the pathogenic species. EVs produced by pathogenic members of the Cryptococcus genus mediate virulence, antifungal resistance, as well as humoral and cell-mediated immunity. The isolation of cryptococcal EVs has been laborious and time-consuming for years. In this chapter, we detail a fast protocol for the isolation and analysis of EVs produced by members of the Cryptococcus genus.
Assuntos
Cryptococcus , Vesículas Extracelulares , Vesículas Extracelulares/metabolismo , Criptococose/microbiologia , Criptococose/imunologia , HumanosRESUMO
Glucuronoxylomannan (GXM) is the principal capsular component in the Cryptococcus genus. This complex polysaccharide participates in numerous events related to the physiology and pathogenesis of Cryptococcus, which highlights the importance of establishing methods for its isolation and analysis. Conventional methods for GXM isolation have been extensively discussed in the literature. In this chapter, we describe two fast methods for obtaining extracellular fractions enriched with cryptococcal GXM.
Assuntos
Cryptococcus , Polissacarídeos , Polissacarídeos/química , Antígenos de Fungos/imunologia , Cryptococcus neoformans , Cápsulas Fúngicas/metabolismo , Cápsulas Fúngicas/química , HumanosRESUMO
An amplicon metagenomic approach based on the ITS2 region of fungal rDNA was used to investigate the diversity of fungi associated with mature strawberries collected from a volcanic orchard and open-air market stands. Based on the Kruskal-Wallis test, no statistically significant differences were observed in both non-phylogenetic and phylogenetic alpha diversity indices. According to beta diversity analyses, significant differences in fungal communities were found between groups (orchard vs. market). Taxonomic assignment of amplicon sequence variables (ASVs) revealed 7 phyla and 31 classes. The prevalent fungal phyla were Basidiomycota (29.59-84.58%), Ascomycota (15.33-70.40%), and Fungi-phy-Insertae-sedis (0.45-2.89%). The most predominant classes among the groups were Saccharomycetes in the market group, and Microbotryomycetes and Tremellomycetes in the orchard group. Based on the analysis of microbiome composition (ANCOM), we found that the most differentially fungal genera were Hanseniaspora, Kurtzmaniella, and Phyllozyma. Endophytic yeasts Curvibasidium cygneicollum were prevalent in both groups, while Candida railenensis was detected in fruits originating only from the market. In addition, Rhodotorula graminis (relative abundance varying from 1.7% to 21.18%) and Papiliotrema flavescens (relative abundance varying from 1.58% to 16.55%) were detected in all samples regardless of origin, while Debaryomyces prosopidis was detected in samples from the market only, their relative abundance varying with the sample (from 0.80% to 19.23%). Their role in fruit quality and safety has not been yet documented. Moreover, several clinically related yeasts, such as Meyerozyma guilliermondii and Candida parapsilosis, were detected in samples only from the market. Understanding the variety and makeup of the mycobiome in ripe fruits during the transition from the orchard to the market is crucial for fruit safety after harvest.
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INTRODUCTION: Meningeal cryptococcosis (MC) is a frequent cause of meningoencephalitis in people living with HIV (PLHIV), leading to substantial morbidity (20-55%). Clinical characteristics, lethality and adverse prognostic factors in PLHIV with MC admitted to intensive care units (ICUs) are described. METHODS: A retrospective observational study. Period from 11/21/2006 to 05/24/2023. It involved 154 adult PLHIV diagnosed with MC and admitted to ICUs. Percentages and absolute values were compared by Chi-Square or Fisher's test and medians by Mann-Whitney test. The association with mortality was assessed by logistic regression. SPSS 23.0 software was used. A p-value <0.05 was considered significant. RESULTS: Patients who died and those who survived were comparable in age and sex (p>0.05). Univariate analysis showed that impaired functional and nutritional status, lack of previous highly active antiretroviral therapy, CD4 <100 cells, APACHE II ≥ 13 and a PLHIV prognostic score ≥ 8 points, requiring mechanical ventilation (MV), respiratory failure, renal failure, neurological dysfunction or sepsis could be associated (p<0.05) with mortality. Logistic regression established that impaired functional and nutritional status, a PLHIV prognostic score ≥ 8, need for MV and presence of sepsis would be independent variables associated with mortality. CONCLUSION: The results indicate that altered functional and nutritional status, a PLHIV prognostic score ≥ 8 points, requiring MV and suffering sepsis on admission to the ICU are more frequent in deceased patients, and they could therefore serve as independent variables to predict a higher risk of mortality.
Introducción: La criptococosis meníngea (CM) es una causa frecuente de meningoencefalitis en personas que viven con HIV (PVHIV) y produce una importante morbimortalidad (20-55%). Se describen las características clínicas, la letalidad y las variables de mal pronóstico en PVHIV con CM, en unidades de cuidados intensivos (UCI). Métodos: Estudio observacional y retrospectivo. Período 21/11/2006 a 24/05/2023. Población evaluada: 154 PVHIV adultos, admitidos en UCI con diagnóstico de CM. Los porcentajes y valores absolutos, fueron comparados mediante Chi-Cuadrado o test de Fisher y las medianas mediante test de Mann-Whitney. La asociación con mortalidad se evaluó por regresión logística. Se utilizó el programa SPSS 23.0. Un valor p<0.05 fue considerado significativo. Resultados: Los pacientes que fallecieron y los que sobrevivieron fueron comparables en edad y sexo (p>0.05). El análisis univariado, observó que un estado funcional y nutricional alterado, falta de tratamiento antirretroviral previo (TARV), CD4 <100 células/µl, APACHE II ≥ 13 y un score pronóstico de PVHIV ≥ 8 puntos, requerir ventilación mecánica (VM), sufrir insuficiencia respiratoria, renal, disfunción neurológica o sepsis, podrían estar asociados (p<0.05) con mortalidad. La regresión logística estableció que un estado funcional y nutricional alterado, un score pronóstico PVHIV ≥ 8, necesitar VM y sufrir sepsis serían variables independientes asociadas a mortalidad. Conclusión: Los resultados indican que el estado funcional y nutricional alterado, un score pronóstico PVHIV ≥ 8 puntos, requerir VM y sufrir sepsis al ingreso a UCI podrían servir como variables independientes para predecir un mayor riesgo de mortalidad.
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Infecções Oportunistas Relacionadas com a AIDS , Unidades de Terapia Intensiva , Meningite Criptocócica , Humanos , Masculino , Feminino , Estudos Retrospectivos , Adulto , Meningite Criptocócica/mortalidade , Meningite Criptocócica/complicações , Pessoa de Meia-Idade , Infecções Oportunistas Relacionadas com a AIDS/mortalidade , Infecções Oportunistas Relacionadas com a AIDS/complicações , Unidades de Terapia Intensiva/estatística & dados numéricos , Prognóstico , Fatores de Risco , Infecções por HIV/complicações , Infecções por HIV/mortalidadeRESUMO
Cryptococcosis is one of the major life-threatening opportunistic/systemic fungal diseases of worldwide occurrence, which can be asymptomatic or establish pneumonia and meningoencephalitis mainly in immunosuppressed patients, caused by the Cryptococcus neoformans and C. gattii species complexes. Acquisition is by inhaling fungal propagules from avian droppings, tree hollows and decaying wood, and the association of the molecular types with geographic origin, virulence and antifungal resistance have epidemiological importance. Since data on cryptococcosis in Alagoas are limited, we sought to determine the molecular types of etiological agents collected from clinical and environmental sources. We evaluated 21 isolates previously collected from cerebrospinal fluid and from environment sources (pigeon droppings and tree hollows) in Maceió-Alagoas (Brazil). Restriction fragment length polymorphism of URA5 gene was performed to characterize among the eight standard molecular types (VNI-VNIV and VGI-VGIV). Among isolates, 66.67% (14) were assigned to C. neoformans VNI - 12 of them (12/14) recovered from liquor and 2 from a tree hollow (2/14). One isolate from pigeon droppings (4.76%) corresponded to C. neoformans VNIV, while five strains from tree hollows and one from pigeon droppings (6, 28.57%) to C. gattii VGII. VNI-type was present in clinical and environmental samples and most C. neoformans infections were observed in HIV-positive patients, while types VNIV and VGII were prevalent in environmental sources in Alagoas. This is the first molecular characterization of Cryptococcus spp. in Alagoas, our study provides additional information on the ecoepidemiology of Cryptococcus spp. in Brazil, contributing to a closer view of the endemic species.
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Columbidae , Criptococose , Cryptococcus gattii , Cryptococcus neoformans , Microbiologia Ambiental , Cryptococcus neoformans/genética , Cryptococcus neoformans/isolamento & purificação , Cryptococcus neoformans/classificação , Brasil/epidemiologia , Criptococose/microbiologia , Criptococose/epidemiologia , Cryptococcus gattii/genética , Cryptococcus gattii/isolamento & purificação , Cryptococcus gattii/classificação , Humanos , Animais , Columbidae/microbiologia , Técnicas de Tipagem Micológica , Polimorfismo de Fragmento de Restrição , Fezes/microbiologia , GenótipoRESUMO
Cryptococcosis is an invasive mycosis caused mainly by Cryptococcus gattii and C. neoformans and is treated with amphotericin B (AMB), fluconazole and 5-fluorocytosine. However, antifungal resistance, limited and toxic antifungal arsenal stimulate the search for therapeutic strategies such as drug repurposing. Among the repurposed drugs studied, the selective serotonin reuptake inhibitors (SSRIs) have shown activity against Cryptococcus spp. However, little is known about the antifungal effect of duloxetine hydrochloride (DH), a selective serotonin and norepinephrine reuptake inhibitor (SSNRI), against C. neoformans and C. gattii. In this study, DH inhibited the growth of several C. neoformans and C. gattii strains at concentrations ranging from 15.62 to 62.50 µg/mL. In addition, DH exhibited fungicidal activity ranging from 15.62 to 250 µg/mL. In biofilm, DH treatment reduced Cryptococcus spp. biomass at a level comparable to AMB, with a significant reduction (85%) for C. neoformans biofilms. The metabolic activity of C. neoformans and C. gattii biofilms decreased significantly (99%) after treatment with DH. Scanning electron micrographs confirmed the anti-biofilm activity of DH, as isolated cells could be observed after treatment. In conclusion, DH showed promising antifungal activity against planktonic cells and biofilms of C. neoformans and C. gattii, opening perspectives for further studies with DH in vivo.
Assuntos
Antifúngicos , Biofilmes , Cryptococcus gattii , Cryptococcus neoformans , Cloridrato de Duloxetina , Testes de Sensibilidade Microbiana , Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Cryptococcus gattii/efeitos dos fármacos , Cloridrato de Duloxetina/farmacologia , Cryptococcus neoformans/efeitos dos fármacos , Cryptococcus neoformans/crescimento & desenvolvimento , Criptococose/tratamento farmacológico , Criptococose/microbiologiaRESUMO
Small molecules are components of fungal extracellular vesicles (EVs), but their biological roles are only superficially known. NOP16 is a eukaryotic gene that is required for the activity of benzimidazoles against Cryptococcus deuterogattii. In this study, during the phenotypic characterization of C. deuterogattii mutants expected to lack NOP16 expression, we observed a reduced EV production. Whole-genome sequencing, RNA-Seq, and cellular proteomics revealed that, contrary to our initial findings, these mutants expressed Nop16 but exhibited altered expression of 14 genes potentially involved in sugar transport. Based on this observation, we designated these mutant strains as Past1 and Past2, representing potentially altered sugar transport. Analysis of the small molecule composition of EVs produced by wild-type cells and the Past1 and Past2 mutant strains revealed not only a reduced number of EVs but also an altered small molecule composition. In a Galleria mellonella model of infection, the Past1 and Past2 mutant strains were hypovirulent. The hypovirulent phenotype was reverted when EVs produced by wild-type cells, but not mutant EVs, were co-injected with the mutant cells in G. mellonella. These results connect EV biogenesis, cargo, and cryptococcal virulence.
RESUMO
Cryptococcus neoformans is responsible for over 100 000 deaths annually, and the treatment of this fungal disease is expensive and not consistently effective. Unveiling new therapeutic avenues is crucial. Previous studies have suggested that the anthelmintic drug fenbendazole is an affordable and nontoxic candidate to combat cryptococcosis. However, its mechanism of anticryptococcal activity has been only superficially investigated. In this study, we examined the global cellular response of C. neoformans to fenbendazole using a proteomic approach (data are available via ProteomeXchange with identifier PXD047041). Fenbendazole treatment mostly impacted the abundance of proteins related to metabolic pathways, RNA processing, and intracellular traffic. Protein kinases, in particular, were significantly affected by fenbendazole treatment. Experimental validation of the proteomics data using a collection of C. neoformans mutants led to the identification of critical roles of five protein kinases in fenbendazole's antifungal activity. In fact, mutants lacking the expression of genes encoding Chk1, Tco2, Tco3, Bub1, and Sch9 kinases demonstrated greater resistance to fenbendazole compared to wild-type cells. In combination with the standard antifungal drug amphotericin B, fenbendazole reduced the cryptococcal burden in mice. These findings not only contribute to the elucidation of fenbendazole's mode of action but also support its use in combination therapy with amphotericin B. In conclusion, our data suggest that fenbendazole holds promise for further development as an anticryptococcal agent.