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The virulence of Cryptococcus spp. is modulated in the natural environment through interaction with abiotic and biotic factors, and this can occasionally have implications for the progression of cryptococcosis in mammals. Hence, we evaluated whether the prior interaction of highly virulent Cryptococcus gattii strain R265 with Acanthamoeba castellanii influenced the progression of cryptococcosis. The influence of the capsule on endocytosis was evaluated using amoeba and yeast morphometrics. Mice were intratracheally infected with yeast re-isolated from the amoeba (Interaction), yeast without prior contact with the amoeba (Non-Interaction), or sterile phosphate-buffered saline (SHAM). Morbidity signs and symptoms were monitored during the survival curve, while cytokine and fungal burden measurements and histopathological analysis were performed on the 10th day post infection. Morbidity and mortality parameters in experimental cryptococcosis were influenced by the prior interaction of yeast with amoeba, which led to phenotypic changes in the cryptococcal cells, polysaccharide secretion, and their tolerance to oxidative stress. Our results suggest that a prior yeast-amoeba interaction modulates yeast virulence, which is associated with a greater tolerance to oxidative stress related to the exo-polysaccharide content and influences the progression of cryptococcal infection.
Assuntos
Amoeba , Criptococose , Cryptococcus gattii , Cryptococcus neoformans , Animais , Camundongos , Saccharomyces cerevisiae , Criptococose/microbiologia , Criptococose/patologia , Polissacarídeos , MamíferosRESUMO
Cinnamaldehyde (CNM) is a cyclic terpene alcohol found as the major compound of essential oils from some plants of the genus Cinnamomum (Lauraceae). CNM has several reported pharmacological activities, including antimicrobial, antivirulence, antioxidant, and immunomodulatory effects. These properties make CNM an attractive lead molecule for the development of anti-infective agents. In this descriptive review, we discuss the application of CNM in experimental models of microbial infection using invertebrate and vertebrate organisms. CNM (pure or in formulations) has been successfully applied in the treatment of infections caused by a range of bacterial (such as Cronobacter sakazakii, Escherichia coli, Listeria monocytogenes, Mycobacterium tuberculosis, Pseudomonas aeruginosa, Salmonella enterica, Staphylococcus aureus, Streptococcus agalactiae, Vibrio cholerae) and fungal (such as Aspergillus fumigatus, Candida albicans and Cryptococcus neoformans) pathogens. All these experimental evidence-based findings have promoted the use of cinnamaldehyde as the leading molecule for developing new anti- infective drugs.
Assuntos
Anti-Infecciosos , Óleos Voláteis , Humanos , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Anti-Infecciosos/farmacologia , Escherichia coli , Testes de Sensibilidade Microbiana , Modelos Teóricos , Terpenos/farmacologiaRESUMO
Failures in endodontic treatments are mostly associated with the difficulty in eradicating microbes of the root canal system, highlighting the need to develop novel effective antimicrobials. Punica granatum (pomegranate) leaf hydroalcoholic extract may be a potential alternative in canal dressing, owing to its antimicrobial properties. The objective of this study was to evaluate the antimicrobial activity of hydroalcoholic leaf extract of Punica granatum (HEPg) alone or in combination with calcium hydroxide (Ca(OH)2) against Enterococcus faecalis and Candida albicans in isolation and in mono- and polymicrobial biofilms. Microdilution tests in broth and assays for inhibition of biofilm formation were carried out to evaluate the antimicrobial properties of HEPg and HEPg + Ca(OH)2 against Enterococcus faecalis and Candida albicans. The cytotoxicity of HEPg in HaCaT cells was evaluated by MTT assay. HEPg and HEPg + Ca(OH)2 exerted significant antimicrobial activity against planktonic cells and mono- and polymicrobial biofilms. The combination of Punica granatum extract with Ca(OH)2 appears to be a promising alternative in endodontic treatments, which could be tested in vivo to confirm the efficacy of this mixture in disinfecting root canal systems.
RESUMO
BACKGROUND: Cryptococcosis affects more than 220,000 patients/year, with high mortality even when the standard treatment [amphotericin B (AMB), 5-flucytosin (5-FC) and fluconazole] is used. AMB presents high toxicity and 5-FC is not currently available in Brazil. In a pre-clinical study, pioglitazone (PIO - an antidiabetic drug) decreased AMB toxicity and lead to an increased mice survival, reduced morbidity and fungal burden in brain and lungs. The aim of this trial is to evaluate the efficacy and safety of PIO combined with standard antifungal treatment for human cryptococcosis. METHODS: A phase 1/2, randomized, double blind, placebo-controlled trial will be performed with patients from Belo Horizonte, Brazil. They will be divided into three groups (placebo, PIO 15 mg/day or PIO 45 mg/day) and will receive an additional pill during the induction phase of cryptococcosis' treatment. Our hypothesis is that treated patients will have increased survival, so the primary outcome will be the mortality rate. Patients will be monitored for survival, side effects, fungal burden and inflammatory mediators in blood and cerebrospinal fluid. The follow up will occur for up 60 days. CONCLUSIONS: We expect that PIO will be an adequate adjuvant to the standard cryptococcosis' treatment. TRIAL REGISTRATION: ICTRP/WHO (and International Clinical Trial Registry Plataform (ICTRP/WHO) (http://apps.who.int/trialsearch/Trial2.aspx?TrialID=RBR-9fv3f4), RBR-9fv3f4 (http://www.ensaiosclinicos.gov.br/rg/RBR-9fv3f4). UTN Number: U1111-1226-1535. Ethical approvement number: CAAE 17377019.0.0000.5149.
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In the present study, novel, 1,3-diaryltriazene-derived triazene compounds were synthesized and tested. Triazenes are versatile and belong to a group of alkylating agents with interesting physicochemical properties and proven biological activities. This study describes the synthesis, molecular and crystalline structure, biological activity evaluation, and antifungal and antimicrobial potentials of 1,3-bis(X-methoxy-Y-nitrophenyl)triazenes [X = 2 and 5; Y = 4 and 5]. The antimicrobial and antifungal activities of the compounds were tested by evaluating the sensitivity of bacteria (American Type Culture Collection, ATCC) and clinical isolates to their solutions using standardized microbiological assays, cytotoxicity evaluation, and ecotoxicity tests. The antimicrobial potentials of triazenes were determined according to their minimum inhibitory concentrations (MICs); these compounds were active against gram-positive and gram-negative bacteria, with low MIC values. The most surprising result was obtained for T3 having the effective MIC of 9.937 µg/mL and antifungal activity against Candida albicans ATCC 90028, C. parapsilosis ATCC 22019, and C. tropicallis IC. To the best of our knowledge, this study is the first to report promising activities of triazene compounds against yeast and filamentous fungi. The results showed the potential utility of triazenes as agents affecting selected resistant bacterial and fungal strains.
Assuntos
Triazenos/química , Triazenos/farmacologia , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Antineoplásicos/química , Antineoplásicos/farmacologia , Relação Dose-Resposta a Droga , Testes de Sensibilidade Microbiana , Modelos Moleculares , Estrutura Molecular , Relação Estrutura-AtividadeRESUMO
BACKGROUND: The infections caused by fungi represent a global concern and an important cause of hospital admissions in endemic areas. The influence of socio-environmental factors in infectious diseases has been documented; however, this phenomenon remains unclear regarding mycoses. OBJECTIVES: This study aimed to analyse the spatio-temporal dynamics of hospitalisations for mycoses (HM) and the association with socio-economic and climate data in the Amazon-Savanna Transition Region in the state of Maranhão, Brazil. METHODS: In this study, Spearman's correlation was applied to determine the correlation between HM, socio-economic and climatic data obtained from national databases in the period from 1998 to 2016. Hospitalisations for mycoses data were spatialised and analysed using the local Moran's index. RESULTS: Our data revealed a negative and significant correlation between HM and socio-economic data regarding population, demographic density, human development index, health facilities and sanitary sewage. Significant correlations were observed between HM and precipitation, maximum temperature and minimum temperature. The main modulating climatic variable was the minimum temperature. The spatial autocorrelation analysis showed the dynamics of HM in municipalities belonging to the different regions of the state influenced by socio-economic conditions. We observed the presence of municipalities with high incidence of HM surrounded by others with low HM cases and vice versa. CONCLUSIONS: Our results indicate that hospitalisations for mycoses represent an important indicator of socio-environmental vulnerability in the Amazon-Savanna transition region in Brazil. We encourage the adoption of measures to mitigate social and environmental impact on these diseases, especially in municipalities with low socio-economic status.
Assuntos
Hospitalização/estatística & dados numéricos , Micoses/epidemiologia , Brasil/epidemiologia , Clima , Atenção à Saúde/estatística & dados numéricos , Demografia , Humanos , Incidência , Prevalência , Chuva , Saneamento/estatística & dados numéricos , Estações do Ano , Fatores Socioeconômicos , Análise Espaço-Temporal , Estatísticas não ParamétricasRESUMO
Climate can modulate human health at large spatial scales, but the influence of global, regional, and local environments remains poorly understood, especially for neglected diseases, such as mycoses. In this work, we present the correlation between climatic variables and hospitalizations for mycoses in Brazilian state capitals, evaluating the period of 2008 to 2016 at different time scales. The results indicate that climate modulates the hospitalizations for mycoses differently at annual and monthly time scales, with minimum temperature as a key climatic variable during periods of high prevalence in the 10 Brazilian capitals with the highest hospitalizations for mycoses rates. The greatest number of hospitalizations coincided with La Niña events, while a reduction was observed during El Niño events, thereby demonstrating the influence of the Pacific Interdecadal Climate Oscillation on the prevalence of mycoses in Brazil. At a regional scale, the mycoses burden in Brazil appears to respond differently to local and global climatic drivers.
Assuntos
Clima , Hospitalização/estatística & dados numéricos , Micoses , Brasil , Humanos , Fatores de TempoRESUMO
Sickle cell anaemia is one of the most common hemoglobinopathies worldwide and an important public health problem in Brazil. This study evaluated the prevalence of sickle cell anaemia and its traits in newborns from the Amazon-Savanna Transition Region in the state of Maranhão, Brazil. A cross-sectional study was carried out, based on data from neonatal screening tests performed in 2013-2015 in Maranhão. The Hardy-Weinberg theorem was applied to analyse the frequency of expected homozygotes based on HbSS phenotype. A spatial-temporal distribution analysis was performed to delimit the regions with the greatest number of newborn cases with sickle cell anaemia. Of 283,003 newborns, 162 were found to have sickle cell anaemia, while 10,794 had a sickle cell trait, with a prevalence of 0.05% and 3.8%, respectively. The prevalence of expected homozygotes was higher in the North Region and in the state capital of Maranhão. This study may contribute to existing social and public health actions or the creation of new strategies for sickle cell disease in endemic areas in Brazil to improve the quality of life.
Assuntos
Anemia Falciforme/epidemiologia , Meio Ambiente , Brasil/epidemiologia , Estudos Transversais , Feminino , Florestas , Pradaria , Humanos , Recém-Nascido , Masculino , Triagem Neonatal , PrevalênciaRESUMO
Cryptococcosis, an invasive fungal infection distributed worldwide that affects both domestic and wild animals, has incredible rates regarding treatment failure, leading to the necessity of the development of new therapies. In this way, we aimed to evaluate the probiotic (Saccharomyces boulardii, Lactobacillus paracasei ST-11, and Lactobacillus rhamnosus GG) and antimicrobial photodynamic alternative therapies against Cryptococcus gattii in a murine model. Although previous studies suggest that these therapies can be promising against cryptococcosis, our experimental conditions for both probiotic and antimicrobial photodynamic therapies (aPDT) were not able to improve the survival of mice with cryptococcosis, even with the treatment combined with fluconazole. Our results may help other researchers to find the best protocol to test alternative therapies against Cryptococcus gattii.
Assuntos
Anti-Infecciosos/farmacologia , Criptococose/terapia , Cryptococcus gattii/efeitos dos fármacos , Probióticos/farmacologia , Animais , Terapias Complementares , Criptococose/microbiologia , Fluconazol/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , FotoquimioterapiaRESUMO
Paracoccidioidomycosis (PCM) is an infectious disease endemic to South America, caused by the thermally dimorphic fungi Paracoccidioides. Currently, there is no effective human vaccine that can be used in prophylactic or therapeutic regimes. We tested the hypothesis that the immunogenicity of the immunodominant CD4+ T-cell epitope (P10) of Paracoccidioides brasiliensis gp43 antigen might be significantly enhanced by using a hepatitis B virus-derived particle (VLP) as an antigen carrier. This chimera was administered to mice as a (His)6-purified protein (rPbT) or a replication-deficient human type 5 adenoviral vector (rAdPbT) in an immunoprophylaxis assay. The highly virulent Pb18 yeast strain was used to challenge our vaccine candidates. Fungal challenge evoked robust P10-specific memory CD4+ T cells secreting protective Th-1 cytokines in most groups of immunized mice. Furthermore, the highest level of fungal burden control was achieved when rAdPbT was inoculated in a homologous prime-boost regimen, with 10-fold less CFU recovering than in non-vaccinated mice. Systemic Pb18 spreading was only prevented when rAdPbT was previously inoculated. In summary, we present here VLP/P10 formulations as vaccine candidates against PCM, some of which have demonstrated for the first time their ability to prevent progression of this pernicious fungal disease, which represents a significant social burden in developing countries.