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1.
Braz J Biol ; 83: e276872, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38055507

RESUMO

Leishmaniasis is a vector-transmitted zoonosis caused by different species of the genus Leishmania, with a wide clinical spectrum. It is a public health problem aggravated by a series of limitations regarding treatment. In the search for new therapeutic alternatives, scorpion venoms are a source of multifunctional molecules that act against the natural resistance of pathogens. This work evaluated the antileishmanial potential of Brotheas amazonicus and Tityus metuendus venoms against the promastigote forms of Leishmania amazonensis e Leishmania guyanensis. The venoms of B. amazonicus and T. metuendus were evaluated for their constituents using Fourier Transform Infrared (FTIR). Growth inhibition and death of promastigotes were evaluated in the presence of diferente crude venom concentrations (100 µg/mL, 50 µg/mL, 10 µg/mL, 1 µg/mL) after one hour of incubation at 25 °C. The FTIR spectra of both venoms exhibited bands in approximate regions, revealing that both exhibit similar functional groups. Crude venom from both scorpion species showed similar or superior leishmanicidal effects to the standart drug N-methylglucamine antimoniate. At the highest concentration of 100 µg/mL, cultures of L. guyanensis treated with the venom of B. amazonicus showed the highest mortality percentages, above 28%, while T. metuendus venom showed the highest activity against L. amazonensis, with mortality above 7%. This preliminar study demonstrates that B. amazonicus and T. metuendus venoms can be important tools in the search for new drugs Against leishmaniasis. Next step involves evaluating the activity against the amastigote forms and purifying the venom proteins in order to identify the best anti-leishmania candidates.


Assuntos
Leishmaniose , Peçonhas , Animais , Humanos , Escorpiões
2.
Braz J Microbiol ; 54(4): 2603-2607, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37702922

RESUMO

In this study, we investigate the ability of Pythium insidiosum to form biofilms across various substrates and the antibiofilm efficacy of 8-hydroxyquinoline derivatives (8-HQs). Biofilms of P. insidiosum were cultured on polystyrene plates, contact lenses, and horsehair. We provide the first evidence of P. insidiosum's biofilm-forming capability, thus considerably expanding our understanding of its transmission and pathogenesis. Our results demonstrate that 8-HQs effectively inhibit biofilm formation and eradicate pre-existing biofilms, underscoring their potential as a novel treatment strategy for pythiosis, a disease currently lacking a gold-standard treatment. This finding has particular relevance for ocular pythiosis associated with contact lens usage and potential infection sources in animals. Our results contribute to the scientific knowledge base and directly impact innovative therapeutic interventions' development.


Assuntos
Pitiose , Pythium , Animais , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Pitiose/tratamento farmacológico , Pitiose/microbiologia
3.
Sci Total Environ ; 836: 155667, 2022 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-35513142

RESUMO

Soil phosphorus (P) availability may limit plant growth and alter root-soil interactions and rhizosphere microbial community composition. The composition of the rhizosphere microbial community can also be shaped by plant genotype. In this study, we examined the rhizosphere microbial communities of young plants of 24 species of eucalypts (22 Eucalyptus and two Corymbia species) under low or sufficient soil P availability. The taxonomic diversity of the rhizosphere bacterial and fungal communities was assessed by 16S and 18S rRNA gene amplicon sequencing. The taxonomic modifications in response to low P availability were evaluated by principal component analysis, and co-inertia analysis was performed to identify associations between bacterial and fungal community structures and parameters related to plant growth and nutritional status under low and sufficient soil P availability. The sequencing results showed that while both soil P availability and eucalypt species influenced the microbial community assembly, eucalypt species was the stronger determinant. However, when the plants are subjected to low P-availability, the rhizosphere selection became strongest. In response to low P, the bacterial and fungal communities in the rhizosphere of some species showed significant changes, whereas in others remained relatively constant under low and sufficient P. Co-inertia analyses revealed a significant co-dependence between plant nutrient contents and bacterial and fungal community composition only under sufficient P. By contrast, under low P, bacterial community composition was related to plant biomass production. In conclusion, our study shows that eucalypt species identity was the main factor modulating rhizosphere microbial community composition; significant shifts due to P availability were observed only for some eucalypt species.


Assuntos
Microbiota , Micobioma , Bactérias , Fungos , Microbiota/fisiologia , Fósforo , Raízes de Plantas/microbiologia , Plantas , Rizosfera , Solo/química , Microbiologia do Solo
4.
Lett Appl Microbiol ; 74(3): 395-404, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34822194

RESUMO

Often associated to the colonization by Candida spp. biofilm, the catheter-related infections are a serious health problem since the absence of a specific therapy. Hence, the main objective of this work was to evaluate the activity of 8-hydroxyquinoline and quinazoline derivatives on Candida spp. biofilms. A quinazoline derivative (PH100) and an 8-hydroxyquinoline derivative (PH157) were tested against nine strains of C. albicans, C. tropicalis and C. parapsilosis, and their biofilms in polystyrene microtitre plates and on polyurethane central venous catheter. The PH157 compound was incorporated into a film-forming system-type formulation and its capacity to inhibit biofilm formation on catheters was evaluated. The compounds were active against planktonic and sessile cells, as well as against the tested biofilms. PH157 compound performed better than the PH100 compound. The formulation containing PH157 presented results very similar to those of the compound in solution, which indicates that its activity was preserved. Both compounds showed activity against Candida spp. strains and their biofilm, with better PH157 activity. The formulation preserved the action of the PH157 compound, in addition, it facilitates its application on the catheter. The structural modifications that these compounds allow can generate compounds that are even more active, both against planktonic cells and biofilms.


Assuntos
Candida , Oxiquinolina , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Biofilmes , Testes de Sensibilidade Microbiana , Quinazolinas
5.
J Appl Microbiol ; 2022 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-36626733

RESUMO

AIMS: To evaluate the antimicrobial activity and to determine the pharmacodynamic characteristics of three 8-hydroxyquinoline derivatives (8-HQs) against Pythium insidiosum, the causative agent of pythiosis. METHODS AND RESULTS: Antimicrobial activity was tested by broth microdilution and MTT assays. The antimicrobial mode of action was investigated using sorbitol protection assay, ergosterol binding assay, and scanning electron microscopy. Clioquinol, PH151, and PH153 were active against all isolates, with MIC values ranging from 0.25 to 2 µg ml-1. They also showed a time- and dose-dependent antimicrobial effect, damaging the P. insidiosum cell wall. CONCLUSIONS: Together, these results reinforce the potential of 8-HQs for developing new drugs to treat pythiosis.

6.
Toxicon ; 199: 87-93, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34126124

RESUMO

Snakebite accidents are a public health problem that affects the whole world, causing thousands of deaths and amputations each year. In Brazil, snakebite envenomations are caused mostly by snakes from the Bothrops genus. The local symptoms are characterized by pain, swelling, ecchymosis, and hemorrhages. Systemic disturbances can lead to necrosis and amputations. The present treatment consists of intravenous administration of bothropic antivenom, which is capable of reversing most of the systemic symptoms, while presenting limitations to treat the local effects, such as hemorrhage and to neutralize the snake venom serine protease (SVSP). In this context, we aimed to evaluate the activity of selective serine protease inhibitors (pepC and pepB) in combination with the bothropic antivenom in vivo. Further, we assessed their possible synergistic effect in the treatment of coagulopathy and hemorrhage induced by Bothrops jararaca venom. For this, we evaluated the in vivo activity in mouse models of local hemorrhage and a series of in vitro hemostasis assays. Our results showed that pepC and pepB, when combinated with the antivenom, increase its protective activity in vivo and decrease the hemostatic disturbances in vitro with high selectivity, possibly by inhibiting botropic proteases. These data suggest that the addition of serine protease inhibitor to the antivenom can improve its overall potential.


Assuntos
Bothrops , Venenos de Crotalídeos , Animais , Antivenenos/farmacologia , Antivenenos/uso terapêutico , Brasil , Venenos de Crotalídeos/toxicidade , Hemorragia/induzido quimicamente , Hemorragia/tratamento farmacológico , Camundongos , Inibidores de Serina Proteinase/farmacologia , Inibidores de Serina Proteinase/uso terapêutico
7.
Environ Geochem Health ; 43(11): 4553-4576, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33900510

RESUMO

Mining has become one of the main factors in the global biogeochemical cycle of potentially toxic elements. Therefore, it is considered one of the anthropogenic activities with the greatest negative impact on the environment. These impacts are maximized in semiarid regions, where mining activities can lead to soil degradation and decrease in land productivity. This study aimed to assess the level of contamination in natural, urban, and agricultural soils of three important mining areas, where approximately 80,000 people live, and pollution levels have never been determined before. For this purpose, soil samples were collected around iron, uranium, and vanadium mines, as well as in the main human settlements of the region. The concentrations of 34 elements were determined by instrumental neutron analysis activation (INAA) and inductively coupled plasma optical emission spectrometry (ICP OES) techniques. Pollution indices (CF, EF, mCd, PLI, and REEP) revealed that there is a moderate to heavy level of pollution for 89% of the analyzed elements. Additionally, an extreme contamination level was observed in 78% of the samples, for at least one element. Statistical analyses were performed to identify patterns in the distribution and common sources of pollution. The results suggest that the concentrations for Al, Ba, Hf, Na, Pb, Rb, REE, Ta, Th, U, Zn, and Zr are associated with geogenic causes. However, the influence of anthropogenic sources such as agriculture and mining on the accumulation of these elements in soils should not be disregarded. In contrast, the contents of As, Br, Cd, Co, Cr, Cs, Cu, Fe, K, Mn, Ni, Sc, Ti, and V reflect the direct impact of anthropogenic sources.


Assuntos
Metais Pesados , Poluentes do Solo , Brasil , Monitoramento Ambiental , Humanos , Metais Pesados/análise , Solo , Poluentes do Solo/análise
8.
Mar Pollut Bull ; 166: 111608, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33838915

RESUMO

Coastal systems are highly productive areas for primary productivity and ecosystem services and host a large number of human activities. Since industrialization, metal micronutrients in these regions have increased. Phytoplankton use metals as micronutrients in metabolic processes, but in excess, had deleterious effects. In coastal systems, picoeukaryotes represent a diverse and abundant group with widespread distribution and fundamental roles in biogeochemical cycling. We combined different approaches to explore picoeukaryotes seasonal variability in a chronically metal polluted coastal area at the south-eastern Pacific Ocean. Through remote and field measurements to monitor environmental conditions and 18S rRNA gene sequencing for taxonomic profiling, we determined metal chronic effect on picoeukaryote community's structure. Our results revealed a stable richness and a variable distribution of the relative abundance, despite the physicochemical seasonal variations. These results suggest that chronic metal contamination influences temporal heterogeneity of picoeukaryote communities, with a decoupling between abiotic and biotic patterns.


Assuntos
Ecossistema , Água do Mar , Humanos , Micronutrientes , Oceano Pacífico , RNA Ribossômico 18S
9.
Pharmazie ; 76(2): 68-76, 2021 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-33714282

RESUMO

Ocular toxoplasmosis is the major cause of infectious posterior uveitis worldwide, inducing visual field defect and/or blindness. Despite the severity of this disease, an effective treatment is still lacking. In this study, spiramycin-loaded PLGA implants were developed aiming at the treatment of ocular toxoplasmosis. Implants were manufactured by a hot-molding technique, characterized by Fourier Transform Infrared Spectroscopy, X-Ray Diffraction, Differential Scanning Calorimetry, Scanning Electron Microscopy; evaluated in terms of ocular biocompatibility by immunofluorescence, flow cytometry, cell migration, Hen's egg test-chorioallantoic membrane (HET-CAM) irritation test; and investigated in terms of in vitro efficacy against Toxoplasma gondii . Characterization techniques indicated that spiramycin was dispersed into the polymeric chains and both substances preserved their physical structures in implants. The HET-CAM test indicated that implants did not induce hemorrhage or coagulation, being non-irritant to the CAM. ARPE-19 cells showed viability by MTT assay, and normality in cell cycle kinetics and morphology, without stimulating cell death by apoptosis. Finally, they were highly effective against intracellular parasites without inducing human retinal pigment epithelial cell death. In conclusion, spiramycin-loaded PLGA implants represent a promising therapeutic alternative for the local treatment of ocular toxoplasmosis.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Espiramicina/administração & dosagem , Toxoplasmose Ocular/tratamento farmacológico , Animais , Técnicas de Cultura de Células , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Galinhas , Membrana Corioalantoide , Células Epiteliais , Humanos , Microscopia Eletrônica de Varredura , Epitélio Pigmentado da Retina , Espiramicina/uso terapêutico , Toxoplasma/efeitos dos fármacos
10.
J Appl Microbiol ; 131(3): 1440-1451, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33565222

RESUMO

AIM: The purpose of this study was to evaluate the in vitro and in vivo efficiency of derivatives of 8-Hydroxyquinoline (8HQ) in controlling the fungus Ilyonectria liriodendri. METHODS AND RESULTS: The in vitro tests consisted of assessing its susceptibility to the minimal inhibitory concentration (MIC) and the inhibition of mycelial growth. While the in vivo tests consisted of applying and assessing the most effective products for the protection of wounds, in both preventive + curative and curative forms. The MIC values for PH 151 (6·25 µg ml-1 ) showed better results when compared to the fungicides tebuconazole (>50 µg ml-1 ) and mancozeb (12·5 µg ml-1 for strain 176 and 25 µg ml-1 for strain 1117). PH 151 significantly inhibited mycelial growth, while mancozeb did not differ from the control. In in vivo tests, PH 151 again demonstrated excellent results in vitro, especially when applied preventively. CONCLUSIONS: The derivative of 8HQ PH 151 was effective in controlling the fungus I. liriodendri in vitro and proved to be a promising option for protecting wounds. SIGNIFICANCE AND IMPACT OF THE STUDY: This study points to the prospect of an effective and safe preventive antifungal product, which would enable the use of pesticides in vine culture to be reduced.


Assuntos
Fungicidas Industriais/farmacologia , Hypocreales , Oxiquinolina , Doenças das Plantas , Vitis/microbiologia , Hypocreales/patogenicidade , Testes de Sensibilidade Microbiana , Oxiquinolina/farmacologia , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle
11.
J Appl Microbiol ; 130(6): 1925-1934, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33128257

RESUMO

AIM: The purpose of this study was to evaluate the antifungal activity and toxicological parameters of 8-hydroxyquinoline derivatives PH151 and PH153 using alternative animal models, to understand their behaviour when subjected to in vivo experiments. METHODS AND RESULTS: We used Toll-deficient Drosophila melanogaster to test the protective effect of compounds against Candida albicans infection. Toxicological parameters were investigated in chicken and zebrafish embryos. PH151 and PH153 showed low toxicity and the treated flies with these compounds had a significantly higher survival rate than untreated flies after 7 days of infection. The compounds did not cause interruption of chicken embryogenesis. Zebrafish embryos exposed to compounds showed dose-dependent toxicity. CONCLUSIONS: The data supported the potential of PH151 and PH153 for the treatment of systemic candidiasis and demonstrated to be appropriate drug candidates for further studies using mammalian models. SIGNIFICANCE AND IMPACT OF THE STUDY: The increased incidence of Candida infections resistant to antifungals currently available requires acceleration of the discovery of new agents with properties of inhibiting this fungal pathogen. In this study, we have described the antifungal potential and toxicity of two 8-hydroxyquinoline derivatives using in vivo alternative models, and the results confirm their potential to be developed as new drug candidates.


Assuntos
Antifúngicos/uso terapêutico , Candidíase/tratamento farmacológico , Modelos Animais de Doenças , Oxiquinolina/uso terapêutico , Sulfonamidas/uso terapêutico , Animais , Antifúngicos/química , Candida albicans/efeitos dos fármacos , Candidíase/microbiologia , Embrião de Galinha , Drosophila melanogaster , Oxiquinolina/química , Sulfonamidas/química , Peixe-Zebra
12.
Braz. j. med. biol. res ; 54(2): e10107, 2021. graf
Artigo em Inglês | LILACS, ColecionaSUS | ID: biblio-1142578

RESUMO

Ketamine (KET) is an N-methyl-D-aspartate (NMDA) antagonist with rapid and long-lasting antidepressant effects, but how the drug shows its sustained effects is still a matter of controversy. The objectives were to evaluate the mechanisms for KET rapid (30 min) and long-lasting (15 and 30 days after) antidepressant effects in mice. A single dose of KET (2, 5, or 10 mg/kg, po) was administered to male Swiss mice and the forced swim test (FST) was performed 30 min, 15, or 30 days later. Imipramine (IMI, 30 mg/kg, ip), a tricyclic antidepressant drug, was used as reference. The mice were euthanized, separated into two time-point groups (D1, first day after KET injection; D30, 30 days later), and brain sections were processed for glycogen synthase kinase-3 (GSK-3), histone deacetylase (HDAC), brain-derived neurotrophic factor (BDNF), and glial fibrillary acidic protein (GFAP) immunohistochemical assays. KET (5 and 10 mg/kg) presented rapid and long-lasting antidepressant-like effects. As expected, the immunoreactivities for brain GSK-3 and HDAC decreased compared to control groups in all areas (striatum, DG, CA1, CA3, and mainly pre-frontal cortex, PFC) after KET injection. Increases in BDNF immunostaining were demonstrated in the PFC, DG, CA1, and CA3 areas at D1 and D30 time-points. GFAP immunoreactivity was also increased in the PFC and striatum at both time-points. In conclusion, KET changed brain BDNF and GFAP expressions 30 days after a single administration. Although neuroplasticity could be involved in the observed effects of KET, more studies are needed to explain the mechanisms for the drug's sustained antidepressant-like effects.


Assuntos
Animais , Masculino , Coelhos , Encéfalo/efeitos dos fármacos , Encéfalo/enzimologia , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Ketamina/farmacologia , Antidepressivos/farmacologia , Astrócitos , Quinase 3 da Glicogênio Sintase , Modelos Animais de Doenças , Proteína Glial Fibrilar Ácida , Histona Desacetilases
13.
Braz J Med Biol Res ; 54(2): e10107, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33331415

RESUMO

Ketamine (KET) is an N-methyl-D-aspartate (NMDA) antagonist with rapid and long-lasting antidepressant effects, but how the drug shows its sustained effects is still a matter of controversy. The objectives were to evaluate the mechanisms for KET rapid (30 min) and long-lasting (15 and 30 days after) antidepressant effects in mice. A single dose of KET (2, 5, or 10 mg/kg, po) was administered to male Swiss mice and the forced swim test (FST) was performed 30 min, 15, or 30 days later. Imipramine (IMI, 30 mg/kg, ip), a tricyclic antidepressant drug, was used as reference. The mice were euthanized, separated into two time-point groups (D1, first day after KET injection; D30, 30 days later), and brain sections were processed for glycogen synthase kinase-3 (GSK-3), histone deacetylase (HDAC), brain-derived neurotrophic factor (BDNF), and glial fibrillary acidic protein (GFAP) immunohistochemical assays. KET (5 and 10 mg/kg) presented rapid and long-lasting antidepressant-like effects. As expected, the immunoreactivities for brain GSK-3 and HDAC decreased compared to control groups in all areas (striatum, DG, CA1, CA3, and mainly pre-frontal cortex, PFC) after KET injection. Increases in BDNF immunostaining were demonstrated in the PFC, DG, CA1, and CA3 areas at D1 and D30 time-points. GFAP immunoreactivity was also increased in the PFC and striatum at both time-points. In conclusion, KET changed brain BDNF and GFAP expressions 30 days after a single administration. Although neuroplasticity could be involved in the observed effects of KET, more studies are needed to explain the mechanisms for the drug's sustained antidepressant-like effects.


Assuntos
Antidepressivos/farmacologia , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Encéfalo/efeitos dos fármacos , Encéfalo/enzimologia , Ketamina , Animais , Astrócitos , Modelos Animais de Doenças , Proteína Glial Fibrilar Ácida , Quinase 3 da Glicogênio Sintase , Histona Desacetilases , Ketamina/farmacologia , Masculino , Camundongos
14.
Anim Genet ; 51(6): 899-909, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33006182

RESUMO

The presence of intermuscular bones in fisheries products limits the consumption and commercialization potential of many fish species, including tambaqui (Colossoma macropomum). These bones have caused medical emergencies and are an undesirable characteristic for fish farming because their removal is labor-intensive during fish processing. Despite the difficulty in identifying genes related to the lack of intermuscular bone in diverse species of fish, the discovery of individuals lacking intermuscular bones in a Neotropical freshwater characiform fish has provided a unique opportunity to delve into the genetic mechanisms underlying the pathways of intermuscular bone formation. In this study, we carried out a GWAS among boneless and wt tambaqui populations to identify markers associated with a lack of intermuscular bone. After analyzing 11 416 SNPs in 360 individuals (12 boneless and 348 bony), we report 675 significant (Padj  < 0.003) associations for this trait. Of those, 13 associations were located near candidate genes related to the reduction of bone mass, promotion of bone formation, inhibition of bone resorption, central control of bone remodeling, bone mineralization and other related functions. To the best of our knowledge, for the first time, we have successfully identified genes related to a lack of intermuscular bones using GWAS in a non-model species.


Assuntos
Osso e Ossos/anatomia & histologia , Caraciformes/genética , Estudos de Associação Genética/veterinária , Osteogênese/genética , Animais , Brasil , Caraciformes/anatomia & histologia , Frequência do Gene , Ligação Genética , Desequilíbrio de Ligação , Polimorfismo de Nucleotídeo Único , Peixe-Zebra
15.
Environ Entomol ; 49(5): 1019-1025, 2020 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-32869087

RESUMO

The giant cicada Quesada gigas (Olivier, 1790) (Hemiptera: Cicadidae) is a major pest of coffee plants in Brazil. To ensure the rational management and ecological equilibrium, information about the behavior, dispersion, and reproduction of giant cicada is fundamental. The present work was conducted in an area of 97 ha planted with Coffea arabica L. to investigate adult dispersion as well as mating and oviposition behaviors of Q. gigas. A sound trap was placed at a 'release point' used for the attraction, marking, and release of adults in the area. The recapture of insects was performed with the same sound trap positioned at 20 points distributed at 100, 250, 400, and 1,000 m from the release point. The highest recapture rates of Q. gigas were observed at 100 m from the release point, and the lowest recapture rates were observed at 1,000 m. The presence of Eucalyptus plants in the area apparently influenced dispersion, as high recapture rates were observed at the sites close to Eucalyptus plants. One copulation of Q. gigas lasted 41.6 ± 0.43 min, and the period of a single oviposition bout was 30.0 ± 0.20 min. Quesada gigas adult longevity in the field was estimated to be 49 d. Both males and females were observed performing multiple matings.


Assuntos
Coffea , Hemípteros , Animais , Brasil , Café , Feminino , Masculino , Oviposição
16.
Epidemiol Infect ; 148: e47, 2020 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-32079552

RESUMO

The relative contribution of imported vs. locally acquired infections to urban malaria burden remains largely unexplored in Latin America, the most urbanised region in the developing world. Here we use a simple molecular epidemiology framework to examine the transmission dynamics of Plasmodium vivax in Mâncio Lima, the Amazonian municipality with the highest malaria incidence rate in Brazil. We prospectively genotyped 177 P. vivax infections diagnosed in urban residents between June 2014 and July 2015 and showed that local parasites are structured into several lineages of closely related microsatellite haplotypes, with the largest genetic cluster comprising 32% of all infections. These findings are very unlikely under the hypothesis of multiple independent imports of parasite strains from the rural surroundings. Instead, the presence of an endemic near-clonal parasite lineage circulating over 13 consecutive months is consistent with a local P. vivax transmission chain in the town, with major implications for malaria elimination efforts in this and similar urban environments across the Amazon.


Assuntos
Transmissão de Doença Infecciosa , Malária Vivax/epidemiologia , Malária Vivax/transmissão , Plasmodium vivax/classificação , Plasmodium vivax/genética , Adolescente , Adulto , Brasil/epidemiologia , Criança , Pré-Escolar , Análise por Conglomerados , Feminino , Genótipo , Técnicas de Genotipagem , Humanos , Incidência , Masculino , Repetições de Microssatélites , Pessoa de Meia-Idade , Plasmodium vivax/isolamento & purificação , Estudos Prospectivos , População Urbana , Adulto Jovem
17.
Mar Pollut Bull ; 150: 110701, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31796235

RESUMO

Mangroves in the Northwest Coast of South America are contaminated with heavy metals due to wastewater discharges from industries, affecting the biota from this environment. However, bacteria proliferate in these harsh environmental conditions becoming possible sentinel of these contaminations. In this study, bacterial community composition was analyzed by throughput sequencing of the 16S rRNA gene from polluted and pristine mangrove sediments affected by marked differences in heavy metal concentrations. Core bacteria were dominated by Proteobacteria, Firmicutes, and Bacteroidetes phyla, with strong differences between sites at class and genus levels, correlated with metal levels. Increment of abundance on specific OTUs were associated with either elevated or decreased concentrations of metals and with the sulfur cycle. The abundance of Sulfurovum lithotrophicum, Leptolinea tardivitalis, Desulfococcus multivorans and Aminobacterium colombiense increases when metals rise. On contrary, Bacillus stamsii, Nioella nitrareducens and Clostridiisalibacter paucivorans abundance increases when metal levels are reduced. We propose these OTUs as bacterial sentinels, whose abundance can help monitor the restoration programs of contaminated mangrove sediments in the future.


Assuntos
Monitoramento Ambiental , Sedimentos Geológicos/microbiologia , Metais Pesados , Poluentes Químicos da Água/análise , Áreas Alagadas , Bactérias , RNA Ribossômico 16S , América do Sul
18.
J Appl Microbiol ; 128(4): 1038-1049, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31816165

RESUMO

AIM: The purpose of this study was to uncover insights into the mechanism of action of the 8-hydroxyquinoline derivatives PH151 and PH153. In addition, with the future perspective of developing a topical drug for the treatment of candidiasis and dermatophytosis, the antifungal activity of a nanoemulsion formulation containing the most active compound (PH151) is also presented here. METHODS AND RESULTS: Sorbitol protection assay and scanning electron microscopy indicate that the 8-hydroxyquinoline derivatives act on the cell wall of Candida sp. and dermatophytes and they inhibit the pseudohyphae formation of C. albicans. These findings demonstrate a strong effect of these compounds on C. albicans morphogenesis, which can be considered a potential mode of action for this molecule. Besides, the nanoemulsion formulation MIC values ranged from 0·5 to 4 µg ml-1 demonstrating the significant antifungal activity when incorporated into a pharmaceutical formulation. CONCLUSIONS: Taken together, the results support the potential of these molecules as promising antifungal candidates for the treatment of candidiasis and dermatophytosis. SIGNIFICANCE AND IMPACT OF THE STUDY: There is an emerging need to fill the pipeline with new antifungal drugs due to the limitations presented by the currently used drugs. In this study, we have described a novel formulation with a 8-hydroxyquinoline-5-sulfonamide derivative which has presented a great potency in providing a finished product. Furthermore, the derivative has shown a selective mechanism of action confirming its potential to be developed into a new drug candidate.


Assuntos
Antifúngicos/farmacologia , Arthrodermataceae/efeitos dos fármacos , Dermatomicoses/microbiologia , Oxiquinolina/farmacologia , Sulfonamidas/farmacologia , Antifúngicos/química , Arthrodermataceae/crescimento & desenvolvimento , Candida albicans/efeitos dos fármacos , Candida albicans/crescimento & desenvolvimento , Candidíase/tratamento farmacológico , Candidíase/microbiologia , Parede Celular/efeitos dos fármacos , Dermatomicoses/tratamento farmacológico , Hifas/efeitos dos fármacos , Hifas/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Oxiquinolina/química , Sulfonamidas/química
19.
Animal ; 13(2): 333-340, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29983126

RESUMO

The aim of this study was to evaluate transcriptome changes in the muscle tissue of Bos taurus indicus cull cows subjected to recovery weight gain under grazing conditions. In all, 38 Nellore cull cows were divided randomly into two different management groups: (1) Maintenance (MA) and (2) Recovery gain (RG) from weight loss by moderate growth under high forage availability. After slaughter, RNA analysis was performed on the Longissimus thoracis muscle. Semaphorin 4A, solute carrier family 11 member 1, and Ficolin-2 were expressed in the RG, which may indicate an inflammatory response during tissue regrowth. Signaling factors, such as Myostatin, related to fibroblast activation, negative control of satellite cell proliferation in adults and muscle protein synthesis were less abundant in the RG group. The only gene related to anabolic processes that were more abundant in the MA group was related to fat deposition. The genes that were differentially expressed in the experiment showed muscle repair-related changes during RG based on the greater expression of genes involved in inflammatory responses and the lower expression of negative regulators of muscle cell proliferation and hypertrophy.


Assuntos
Bovinos/genética , Matriz Extracelular/genética , Expressão Gênica , Músculo Esquelético/metabolismo , Transcriptoma/fisiologia , Aumento de Peso , Animais , Bovinos/fisiologia , Dieta , Feminino , Distribuição Aleatória
20.
Lett Appl Microbiol ; 66(1): 2-13, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29112282

RESUMO

Undeniably, new antifungal treatments are necessary against pathogenic fungi. Fungal infections have significantly increased in recent decades, being highlighted as important causes of morbidity and mortality, particularly in immunocompromised patients. Five main antifungal classes are used: (i) azoles, (ii) echinocandins, (iii) polyenes, (iv) allylamines and (v) pyrimidine analogues. Moreover, the treatment of mycoses has several limitations, such as undesirable side effects, narrow activity spectrum, a small number of targets and fungal resistance, which are still of major concern in clinical practice. The discovery of new antifungals is mostly achieved by the screening of natural or synthetic/semisynthetic chemical compounds. The most recent discoveries in drug resistance mechanism and their avoidance were explored in a review, focusing on different antifungal targets, as well as new agents or strategies, such as combination therapy, that could improve antifungal therapy. SIGNIFICANCE AND IMPACT OF THE STUDY: The failure to respond to antifungal therapy is complex and is associated with microbiological resistance and increased expression of virulence in fungal pathogens. Thus, this review offers an overview of current challenges in the treatment of fungal infections associated with increased antifungal drug resistance and the formation of biofilms in these opportunistic pathogens. Furthermore, the most recent and potential strategies to combat fungal pathogens are explored here, focusing on new agents as well as innovative approaches, such as combination therapy between antifungal drugs or with natural compounds.


Assuntos
Antifúngicos/farmacologia , Farmacorresistência Fúngica , Fungos/efeitos dos fármacos , Micoses/microbiologia , Animais , Descoberta de Drogas , Fungos/genética , Fungos/fisiologia , Humanos , Micoses/tratamento farmacológico
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