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1.
Gac Med Mex ; 159(1): 44-48, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36930557

RESUMO

INTRODUCTION: Owing to its ability to reduce the toxicity of environmental pollutants that are risk factors for diabetes and obesity, the use of probiotic bacteria might aid the treatment of these diseases. OBJECTIVE: To determine the effects of chronic exposure to low-dose malathion on weight and glucose levels in mice, as well as to evaluate the protective role of a probiotic supplement. METHODS: Weight and serum glucose levels of four groups of mice (control, malathion-exposed [10 ppm], probiotics and malathion + probiotics) were determined every 10 days for 180 days. RESULTS: Malathion administration induced an increase in weight and glucose levels in the malathion group mice in comparison with the other groups. CONCLUSIONS: Consumption of food contaminated with malathion residues increases glucose levels and favors weight gain, while consumption of probiotics reduces the effects generated by residues in food.


INTRODUCCIÓN: Debido a su capacidad para reducir la toxicidad de contaminantes ambientales que constituyen factores de riesgo de diabetes y obesidad, el uso de bacterias probióticas podría ayudar al tratamiento de esas enfermedades. OBJETIVO: Determinar los efectos de la exposición crónica a malatión a dosis bajas sobre el peso y los niveles de glucosa de ratones, así como evaluar el papel protector de un suplemento probiótico. MÉTODOS: Cada 10 días se determinó el peso y la glucosa sérica de cuatro grupos de ratones (de control, expuestos a malatión (10 ppm), probióticos y malatión + probióticos) durante 180 días. RESULTADOS: La administración de malatión provocó un incremento del peso y los niveles de glucosa en los ratones del grupo con malatión comparados con los demás grupos. CONCLUSIONES: El consumo de alimentos contaminados con residuos de malatión aumenta los niveles de glucosa y favorece el incremento del peso; el consumo de probióticos disminuye los efectos generados por los residuos en los alimentos.


Assuntos
Malation , Probióticos , Camundongos , Animais , Malation/toxicidade , Aumento de Peso , Obesidade/prevenção & controle , Probióticos/uso terapêutico , Glucose
2.
Int J Mol Sci ; 23(22)2022 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-36430181

RESUMO

In enteropathogenic Escherichia coli (EPEC), the production of flagella and the type III secretion system (T3SS) is activated in the presence of host cultured epithelial cells. The goal of this study was to investigate the relationship between expression of flagella and the T3SS. Mutants deficient in assembling T3SS basal and translocon components (ΔespA, ΔespB, ΔespD, ΔescC, ΔescN, and ΔescV), and in secreting effector molecules (ΔsepD and ΔsepL) were tested for flagella production under several growth conditions. The ΔespA mutant did not produce flagella in any condition tested, although fliC was transcribed. The remaining mutants produced different levels of flagella upon growth in LB or in the presence of cells but were significantly diminished in flagella production after growth in Dulbecco's minimal essential medium. We also investigated the role of virulence and global regulator genes in expression of flagella. The ΔqseB and ΔqseC mutants produced abundant flagella only when growing in LB and in the presence of HeLa cells, indicating that QseB and QseC act as negative regulators of fliC transcription. The ΔgrlR, ΔperA, Δler, Δhns, and Δfis mutants produced low levels of flagella, suggesting these regulators are activators of fliC expression. These data suggest that the presence of an intact T3SS is required for assembly of flagella highlighting the existence in EPEC of a cross-talk between these two virulence-associated T3SSs.


Assuntos
Escherichia coli Enteropatogênica , Proteínas de Escherichia coli , Humanos , Escherichia coli Enteropatogênica/genética , Escherichia coli Enteropatogênica/metabolismo , Sistemas de Secreção Tipo III/genética , Sistemas de Secreção Tipo III/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Células HeLa , Regulação Bacteriana da Expressão Gênica , Flagelos/genética , Flagelos/metabolismo
3.
Int J Mol Sci ; 23(18)2022 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-36142263

RESUMO

The attachment of enteropathogenic Escherichia coli (EPEC) to intestinal epithelial cells is facilitated by several adhesins; however, the individual host-cell receptors for pili-mediated adherence have not been fully characterized. In this study, we evaluated the hypothesis that the E. coli common pilus (ECP) tip adhesin protein EcpD mediates attachment of EPEC to several extracellular matrix (ECM) glycoproteins (fibronectin, laminin, collagens I and IV, and mucin). We found that the ΔecpA mutant, which lacks production of the EcpA filament but retains EcpD on the surface, adhered to these glycoproteins below the wild-type levels, while the ΔecpD mutant, which does not display EcpA or EcpD, bound significantly less to these host glycoproteins. In agreement, a purified recombinant EcpD subunit bound significantly more than EcpA to laminin, fibronectin, collagens I and IV, and mucin in a dose-dependent manner. These are compelling data that strongly suggest that ECP-producing EPEC may bind to host ECM glycoproteins and mucins through the tip adhesin protein EcpD. This study highlights the versatility of EPEC to bind to different host proteins and suggests that the interaction of ECP with the host's ECM glycoproteins may facilitate colonization of the intestinal mucosal epithelium.


Assuntos
Escherichia coli Enteropatogênica , Infecções por Escherichia coli , Proteínas de Escherichia coli , Adesinas de Escherichia coli/genética , Adesinas de Escherichia coli/metabolismo , Aderência Bacteriana , Escherichia coli Enteropatogênica/metabolismo , Infecções por Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Proteínas da Matriz Extracelular/genética , Proteínas da Matriz Extracelular/metabolismo , Fibronectinas/metabolismo , Proteínas de Fímbrias/genética , Proteínas de Fímbrias/metabolismo , Fímbrias Bacterianas/metabolismo , Humanos , Laminina/metabolismo , Mucinas/metabolismo
4.
Exp Eye Res ; 200: 108222, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32898513

RESUMO

We are reporting for the first time the synthesis and application of an innovative nanometric system for the controlled topic release of melatonin in the retina. The ethylcellulose nanocapsules were characterized by diverse physicochemical techniques (scanning electron microscopy, zeta potential, hydrodynamic diameters) and an in vitro release study was done. A complete ex vivo and in vivo trans-corneal permeation and an irritation study were carried out with the new formulations in albino rabbits, to which a retinal degenerative model was induced. The results obtained demonstrate that the in vitro release of melatonin (1 mg/mL and 2 mg/mL) transported by nanocapsules is slower when compared to a solution of melatonin. Greater penetration of melatonin through the cornea was demonstrated by ex vivo and in vivo tests. This can be attributable to an enhanced neuroprotective effect of melatonin on retinal ganglion cells when it is included in ethylcellulose nanocapsules compared to a solution of melatonin. These outstanding findings add promising new perspectives to current knowledge about administrations using nano-technological tools in the treatment of neurodegenerative diseases at the ocular level.


Assuntos
Celulose/análogos & derivados , Melatonina/administração & dosagem , Degeneração Retiniana/tratamento farmacológico , Células Ganglionares da Retina/patologia , Animais , Antioxidantes/administração & dosagem , Celulose/farmacologia , Modelos Animais de Doenças , Composição de Medicamentos , Microscopia Eletrônica de Varredura , Nanopartículas/ultraestrutura , Coelhos , Degeneração Retiniana/diagnóstico , Células Ganglionares da Retina/efeitos dos fármacos
5.
Nanomedicine ; 19: 115-125, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31004811

RESUMO

Pioglitazone (PGZ) is a peroxisome proliferator-activated receptor agonist. Its role in the inflammatory response modulation paves the way for additional therapeutic applications. The purpose of this study was to develop a pioglitazone nanoemulsion (PGZ-NE) in order to investigate its anti-inflammatory efficacy on the skin. To that end, an NE vehicle developed for skin delivery was optimized and characterized. The resulting PGZ-NE showed good anti-inflammatory efficacy by decreasing the expression of inflammatory cytokines IL-6, IL-1ß and TNF-α. The properties of the developed nanocarrier allowed achievement of a high permeation flux of PGZ through the skin as well as a high retained amount in the skin, likely due to the depot effect of ingredients, which assured a prolonged local action, with good skin tolerability among participating individuals. Consequently, these results suggest that PGZ-NE may be used as an alternative treatment for inflammatory skin diseases such as rosacea, atopic dermatitis or psoriasis.


Assuntos
Emulsões/química , Inflamação/tratamento farmacológico , Nanopartículas/química , Pioglitazona/uso terapêutico , Dermatopatias/tratamento farmacológico , Adulto , Animais , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Citocinas/metabolismo , Liberação Controlada de Fármacos , Feminino , Humanos , Inflamação/patologia , Camundongos Endogâmicos BALB C , Nanopartículas/ultraestrutura , Permeabilidade , Pioglitazona/efeitos adversos , Pioglitazona/farmacologia , Reologia , Pele/efeitos dos fármacos , Pele/patologia , Dermatopatias/patologia , Viscosidade
6.
Pharm Res ; 34(8): 1728-1740, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28540502

RESUMO

PURPOSE: In order to obtain dermal vehicles of ketorolac tromethamine (KT) for the local treatment of inflammation and restrict undesirable side effects of systemic levels hydrogels (HGs) of poloxamer and carbomer were developed. METHODS: KT poloxamer based HG (KT-P407-HG) and KT carbomer based HG (KT-C940-HG) were elaborated and characterized in terms of swelling, degradation, porosity, rheology, stability, in vitro release, ex vivo permeation and distribution skin layers. Finally, in vivo anti-inflammatory efficacy and skin tolerance were also assessed. RESULTS: HGs were transparent and kept stable after 3 months exhibiting biocompatible near neutral pH values. Rheological patterns fitted to Herschel-Bulkley for KT-C940-HG and Newton for KT-P407-HG due to its low viscosity at 25°C. Rapid release profiles were observed through first order kinetics. Following the surface the highest concentration of KT from C940-HG was found in the epidermis and the stratum corneum for P407-HG. Relevant anti-inflammatory efficacy of KT-P407-HG revealed enough ability to provide sufficient bioavailability KT to reach easily the site of action. The application of developed formulations in volunteers did not induce any visual skin irritation. CONCLUSIONS: KT-P407-HG was proposed as suitable formulation for anti-inflammatory local treatment without theoretical systemic side effect.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Cetorolaco de Trometamina/farmacologia , Poloxâmero/química , Administração Cutânea , Adulto , Animais , Anti-Inflamatórios não Esteroides/química , Disponibilidade Biológica , Excipientes , Feminino , Humanos , Hidrogéis , Concentração de Íons de Hidrogênio , Cetorolaco de Trometamina/química , Camundongos , Pessoa de Meia-Idade , Modelos Biológicos , Permeabilidade , Porosidade , Absorção Cutânea , Distribuição Tecidual , Viscosidade , Adulto Jovem
7.
Enferm Infecc Microbiol Clin ; 34(1): 29-32, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25735716

RESUMO

OBJECTIVE: To evaluate the effect on creatinine clearance (CG-CrCl, Cockcroft-Gault equation) of switching to boosted protease inhibitor (PI) monotherapy in patients receiving a triple drug antiretroviral regimen containing TDF. METHODS: All patients who had received a TDF-containing regimen for at least one year and had been switched to PI monotherapy were included. A rapid decrease in CG-CrCl during exposure to TDF was defined as a decrease in CG-CrCl at least five times higher than the expected due to age (0.4ml/min/year by the years of exposure to TDF). In this subgroup of patients, we considered improvement if the last value of CG-CrCl on PI monotherapy was 10% higher than the last value of CG-CrCl before switching to PI monotherapy. A multivariate logistic regression was constructed to identify factors associated to renal improvement after switching to bPI monotherapy. RESULTS: 64 patients included. The median (IQR) annual change in CG-CrCl during PI monotherapy was significantly lower than the median (IQR) annual change while exposed to TDF [-0.9 (-4.7 to +2.8) ml/min vs. -4 (-8 to -1) ml/min, p=0.001]. 44 patients experienced a rapid decline during TDF exposition. After switch to PI monotherapy, 15/44 (34%, 95% CI: 21-50%) had an improved CG-CrCl and 16/44 (36%, CI 23-52%) experienced a further decline in CG-CrCl. The only variable associated to CG-CrCl improvement was a more rapid CG-CrCl decline in the last year of exposure to TDF. CONCLUSION: Switching to PI monotherapy partially reversed CG-CrCl decrease associated to TDF use, especially in patients with a more rapid decline while receiving TDF.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Infecções por HIV/tratamento farmacológico , Rim/efeitos dos fármacos , Inibidores de Proteases/uso terapêutico , Tenofovir/uso terapêutico , Adulto , Fármacos Anti-HIV/efeitos adversos , Creatinina/metabolismo , Feminino , Humanos , Rim/metabolismo , Masculino , Estudos Retrospectivos , Tenofovir/efeitos adversos
8.
Nanomedicine ; 11(3): 521-30, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25659643

RESUMO

Oleanolic acid (OA) and ursolic acid (UA) are ubiquitous pentacyclic triterpenes compounds in plants with great interest as anti-inflammatory therapeutics. The aim of this study was the design and optimization of polymeric nanoparticles (NPs) loaded with natural and synthetic mixtures (NM, SM) of these drugs for ophthalmic administration. A 2(3) + star central rotatable composite design was employed to perform the experiments. Results showed optimal and stable formulations with suitable physicochemical properties (mean diameter<225 nm), homogeneous distribution (polydispersity index∼0.1), negatively charged surface (∼-27 mV) and high entrapment efficiency (∼77%). Release and corneal permeation studies showed that NM release was faster than SM. Amounts of drug retained in the corneal tissue were also higher for NM. In vitro and in vivo tests showed no signs of irritation or toxicity and successful in vivo anti-inflammatory efficacy for both formulations, being NM-OA/UA NPs the most effective. From the clinical editor: Oleanolic acid (OA) and ursolic acid (UA) are compounds found in plants with anti-inflammatory properties. The authors in this paper designed nanoparticles (NPs) using poly(dl-lactide-coglycolide) acid (PLGA) loaded with these compounds for ophthalmic administration. Both in vitro and in vivo experiments showed no toxicity and significant anti-inflammatory efficacy. This may provide new drugs for ocular anti-inflammatory treatment.


Assuntos
Anti-Inflamatórios , Sistemas de Liberação de Medicamentos/métodos , Desenho de Fármacos , Oftalmopatias , Nanopartículas/química , Ácido Oleanólico , Triterpenos , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacocinética , Anti-Inflamatórios/farmacologia , Avaliação Pré-Clínica de Medicamentos , Oftalmopatias/tratamento farmacológico , Ácido Oleanólico/química , Ácido Oleanólico/farmacocinética , Ácido Oleanólico/farmacologia , Coelhos , Triterpenos/química , Triterpenos/farmacocinética , Triterpenos/farmacologia , Ácido Ursólico
9.
Clin Infect Dis ; 59(11): 1627-34, 2014 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-25114032

RESUMO

BACKGROUND: The evolution of neurocognitive performance in aviremic human immunodeficiency virus (HIV)-positive patients treated with <3 antiretrovirals is unknown. METHODS: We prospectively included aviremic (≥1 year) HIV-positive patients, without concomitant major neurocognitive confounders, currently receiving boosted lopinavir or darunavir as monotherapy (n = 67) or triple antiretroviral therapy (ART) (n = 67) for ≥1 year. We evaluated neurocognitive function (7 domains) at baseline and after 1 year. We performed analysis of covariance to evaluate if 1 additional year of exposure to monotherapy compared with triple ART had an effect on Global Deficit Score (GDS) changes after adjustment for potential confounders. We also compared the evolution of neurocognitive performance and impairment rates. RESULTS: Intention-to-treat analysis showed that monotherapy did not influence 1-year GDS change after adjustment for significant confounders (age, ethnicity, duration of therapy, hepatitis C virus status, and HOMA-IR index); the adjusted effect was -0.04 (95% confidence interval, -.14 to .05; P = .38). Neurocognitive stability was observed with monotherapy and triple therapy (GDS crude mean change, -0.09 [95% confidence interval, -.16 to -.01] vs -0.08 [-.14 to -.02]), after 1 year of follow-up, similar proportions of patients changed neurocognitive status from impaired to unimpaired (monotherapy, 4 of 18 [22.2%]; triple therapy, 4 of 19 [21.1%]; P = .91) and vice versa (monotherapy, 5 of 44 [10.2%] and triple therapy, 3 of 45 [6.3%]; P = .48). Similar results were observed in an on-treatment analysis and with use of clinical ratings instead of GDS changes. CONCLUSIONS: The number of antiretrovirals included in the ART regimen does not seem to influence the evolution of neurocognitive function in HIV-infected patients with suppressed plasma viremia.


Assuntos
Transtornos Cognitivos/virologia , Infecções por HIV/tratamento farmacológico , Inibidores da Protease de HIV/administração & dosagem , Adulto , Terapia Antirretroviral de Alta Atividade , Darunavir , Feminino , Infecções por HIV/fisiopatologia , Infecções por HIV/virologia , Humanos , Estudos Longitudinais , Lopinavir/administração & dosagem , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Sulfonamidas/administração & dosagem
10.
Mycotoxin Res ; 40(4): 467-481, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39096468

RESUMO

The Latin America region has a considerable extent of varied climate conditions: from tropical, subtropical, and warm temperate to temperate. Among the surface territory, different agricultural products are produced, making them an important food source for human consumption. Fungal species commonly colonize those important agricultural products and often contaminate them with mycotoxins that have a major impact on health, welfare, and productivity. Nowadays, special attention is paid to modified mycotoxins, which are those that cannot be detected by conventional analytical methods. However, little data about their natural occurrence in food and feed is available, especially in Latin American countries, where, among all the countries in this region, only a few of them are working on this subject. Thus, the present review summarizes the published information available in order to determine the possible human exposure risk to these toxins.


Assuntos
Contaminação de Alimentos , Micotoxinas , América Latina , Micotoxinas/análise , Humanos , Contaminação de Alimentos/análise , Fungos/isolamento & purificação , Microbiologia de Alimentos
11.
Artigo em Inglês | MEDLINE | ID: mdl-39360361

RESUMO

Infant cereals are typically the first foods introduced as complementary foods. Cereals used to elaborate complementary foods, such as wheat, maize and rice, are susceptible to mycotoxin contamination. Among mycotoxins, fumonisins have been epidemiologically associated, in humans, with oesophageal cancer, neural tube defects and stunting. Fumonisins have been found in maize and wheat grains in Argentina. In the present study, a survey was conducted to determine their occurrence in 82 wheat-based and multicereal-based infant cereal items collected from retail stores in Rio Cuarto, Argentina, using HPLC-MS. Of these samples, 84% showed FBs contamination with levels ranging from 0.05 to 992 µg/kg). Although FB1 was the most prevalent fumonisin, FB2 was found at higher levels. Most samples had levels below the limit of 200 µg/kg set for Argentinean cereal products for children. The outcome of this survey provides information on the naturally presence of fumonisin in infant cereal intended for children in Argentina, which can be helpful to consider relevant monitoring programmes.

12.
Pharmaceutics ; 16(5)2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38794305

RESUMO

Recently, the number of people acquiring tattoos has increased, with tattoos gaining significant popularity in people between 20 and 40 years old. Inflammation is a common reaction associated with tattooing. The purpose of this study was to evaluate a nanostructured lipid carrier loading pranoprofen (PRA-NLC) as a tattoo aftercare formulation to reduce the inflammation associated with tattooing. In this context, the in vitro drug release and the ex vivo permeation-through-human-skin tests using Franz cells were appraised. The tolerance of our formulation on the skin was evaluated by studying the skin's biomechanical properties. In addition, an in vivo anti-inflammatory study was conducted on mice skin to evaluate the efficacy of the formulation applied topically after tattooing the animals. PRA-NLC showed a sustained release up to 72 h, and the amount of pranoprofen retained in the skin was found to be 33.48 µg/g/cm2. The formulation proved to be well tolerated; it increased stratum corneum hydration, and no signs of skin irritation were observed. Furthermore, it was demonstrated to be non-cytotoxic since the cell viability was greater than 80%. Based on these results, we concluded that PRA-NLC represents a suitable drug delivery carrier for the transdermal delivery of pranoprofen to alleviate the local skin inflammation associated with tattooing.

13.
J Environ Sci Health B ; 48(11): 935-40, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23998305

RESUMO

A survey was carried out from 2008 to 2010 to determine the concentrations of 16 organochlorine pesticide residues (OPRs) from Tizayuca, Hidalgo, Mexico. Organochlorine residue determinations were made from milk fat, using chromatographic cleanup and analysis by gas chromatography with an electron capture detector. The OPR concentrations found were from below the detection limit (DL) to 0.91 ng g(-1) in 2008, DL to 0.38 ng g(-1) in 2009 and DL to 0.59 ng g(-1) in 2010. In general concentrations of organochlorine pesticides were higher in the wet season (3.37 ng g(-1) and 4.79 ng g(-1)) than the dry season (1.92 ng g(-1) and 2.71 ng g(-1)) for 2009 and 2010, due to control of pests in the pasture and sheds. According to Codex Alimentarius regulations, individual pesticides did not exceed the permissible limits, which for example were 10 µg kg(-)1 for alpha hexachlorocyclohexane (HCH) and endosulfan I, 20 µg kg(-1) for p,p'-DDT, and 6 µg kg(-1) for dieldrin, endrin and heptachlor. A reduction of organochlorine pesticide concentrations in cow's milk was noted, indicating that the Mexican government has achieved reduction or elimination of some organochlorine pesticides in response to global agreements on persistent organic pollutants.


Assuntos
Exposição Ambiental , Contaminação de Alimentos/análise , Hidrocarbonetos Clorados/análise , Leite/química , Resíduos de Praguicidas/análise , Agricultura , Animais , Cromatografia Gasosa , Monitoramento Ambiental , México , Estações do Ano
14.
Pathogens ; 12(4)2023 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-37111449

RESUMO

Chickpea is susceptible to fungal infection and mycotoxin contamination. Argentina exports most of its chickpea production; thus, its quality is of concern. The Alternaria fungal genus was found to be prevalent in chickpea samples from Argentina. The species within this genus are able to produce mycotoxins, such as alternariol (AOH), alternariol monomethyl ether (AME), and tenuazonic acid (TA). In this context, we evaluated the effect of water activity (0.99, 0.98, 0.96, 0.95, 0.94, 0.92, and 0.90 aW), temperature (4, 15, 25, and 30 °C), incubation time (7, 14, 21, and 28 days), and their interactions on mycelial growth and AOH, AME, and TA production on chickpea-based medium by two A. alternata strains and one A. arborescens strain isolated from chickpea in Argentina. Maximum growth rates were obtained at the highest aW (0.99) and 25 °C, with growth decreasing as the aW of the medium and the temperature were reduced. A. arborescens grew significantly faster than A. alternata. Mycotoxin production was affected by both variables (aW and temperature), and the pattern obtained was dependent on the strains/species evaluated. In general, both A. alternata strains produced maximum amounts of AOH and AME at 30 °C and 0.99-0.98 aW, while for TA production, both strains behaved completely differently (maximum levels at 25 °C and 0.96 aW for one strain and 30 °C and 0.98 aW for the other). A. arborescens produced maximum amounts of the three toxins at 25 °C and 0.98 aW. Temperature and aW conditions for mycotoxin production were slightly narrower than those for growth. Temperature and aW conditions assayed are those found during chickpea grain development in the field, and also could be present during storage. This study provides useful data on the conditions representing a risk for contamination of chickpea by Alternaria toxins.

15.
Pathogens ; 12(5)2023 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-37242406

RESUMO

Fusarium cerealis is a causal agent of Fusarium Head Blight in wheat, and it produces both deoxynivalenol (DON) and nivalenol (NIV). Nevertheless, the effect of environmental factors on the growth and mycotoxin production of this species has not been studied so far. The objective of this study was to investigate the impact of environmental factors on the growth and mycotoxin production of F. cerealis strains. All strains were able to grow in a wide range of water activity (aW) and temperatures, but their mycotoxin production was influenced by strain and environmental factors. NIV was produced at high aW and temperatures, while optimal conditions for DON production were observed at low aW. Interestingly, some strains were able to simultaneously produce both toxins, which could pose a more significant risk for grain contamination.

16.
Mycologia ; 114(1): 46-62, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34871141

RESUMO

The Chaco wetland is among the most biologically diverse regions in Argentina. In collections of fungi from asymptomatic native grasses (Poaceae) from the wetlands, we identified isolates of Fusarium that were morphologically similar to F. armeniacum, but distinct from it by their production of abundant microconidia. All the isolates had identical, or nearly identical, partial sequences of TEF1 and RPB2. But they were distinct from reference sequences from F. armeniacum and Fusarium species closely related to it. Phylogenetic analysis of 34 full-length housekeeping gene sequences retrieved from whole genome sequences of three Chaco wetland isolates, 29 genes resolved the isolates as an exclusive clade within the F. sambucinum species complex. Based on results of the morphological and phylogenetic analysis, we concluded that the Chaco wetland isolates are a distinct and novel species, herein described as Fusarium chaquense, sp. nov., which is closely related to F. armeniacum. F. chaquense in culture can produce the trichothecenes T-2 and HT-2 toxin, neosolaniol, diacetoxyscirpenol, and monoacetoxyscirpenol, as well as beauvericin and the pigment aurofusarin. Genome sequence analysis also revealed the presence of three previously described loci required for trichothecene biosynthesis. This research represents the first study of Fusarium in a natural ecosystem in Argentina.


Assuntos
Fusarium , Tricotecenos , Argentina , Ecossistema , Filogenia , Poaceae , Áreas Alagadas
17.
Microorganisms ; 10(4)2022 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-35456842

RESUMO

The flagella of enteropathogenic Escherichia coli (EPEC) O127:H6 E2348/69 mediate adherence to host proteins and epithelial cells. What environmental and nutritional signals trigger or down-regulate flagella expression in EPEC are largely unknown. In this study, we analyzed the influence of pH, oxygen tension, cationic and anionic salts (including bile salt), carbon and nitrogen sources, and catecholamines on the expression of the flagellin gene (fliC) of E2348/69. We found that sodium bicarbonate, which has been shown to induce the expression of type III secretion effectors, down-regulated flagella expression, explaining why E2348/69 shows reduced motility and flagellation when growing in Dulbecco's Minimal Essential Medium (DMEM). Further, growth under a 5% carbon dioxide atmosphere, in DMEM adjusted to pH 8.2, in M9 minimal medium supplemented with 80 mM glucose or sucrose, and in DMEM containing 150 mM sodium chloride, 0.1% sodium deoxycholate, or 30 µM epinephrine significantly enhanced fliC transcription to different levels in comparison to growth in DMEM alone. When EPEC was grown in the presence of HeLa cells or in supernatants of cultured HeLa cells, high levels (4-fold increase) of fliC transcription were detected in comparison to growth in DMEM alone. Our data suggest that nutritional and host signals that EPEC may encounter in the intestinal niche activate fliC expression in order to favor motility and host colonization.

18.
Toxins (Basel) ; 13(12)2021 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-34941732

RESUMO

Fusarium chaquense, a recently formally described novel species, has been identified as an T-2 toxin (T-2), HT-2 toxin (HT-2) and other toxins producer in natural grasses (Poaceae) from Argentina. The major objective of this study was to describe the effect of water activity (aW, 0.995, 0.98, 0.95, 0.93 and 0.91), temperature (15, 25 and 30 °C) and incubation time (5, 15 and 25 days) on growth and to evaluate the production of T-2, HT-2 toxins and beauvericin (BEA) by two F. chaquense strains in a grass-based media. The results showed a wide range of conditions for F. chaquense growth and mycotoxin production. Both strains had a maximum growth rate at the highest aW (0.995) and 25 °C. Regarding mycotoxin production, more T-2 than the other analysed mycotoxins were produced by the two strains. T-2 production was favoured at 0.995 aW and 30 °C, while HT-2 production at 0.98-0.95 aW and 15 °C. The maximum levels of BEA were produced at 0.995 aW and 25-30 °C. Two-dimensional profiles of aW by temperature interactions were obtained from these data in order to identify areas where conditions indicate a significant risk of mycotoxins accumulation on grass. For its versatility on growth and mycotoxin production in a wide range of aW and temperatures, F. chaquense would have an adaptive advantage over other Fusarium species, and this would explain its high frequency of isolation in natural grasses grown up in the Chaco wetlands.


Assuntos
Fusarium/fisiologia , Tricotecenos do Tipo A/metabolismo , Proliferação de Células , Regulação Fúngica da Expressão Gênica , Micotoxinas/metabolismo , Poaceae/química , Temperatura
19.
Rev Chilena Infectol ; 38(2): 281-289, 2021 Apr.
Artigo em Espanhol | MEDLINE | ID: mdl-34184720

RESUMO

BACKGROUND: Human brucellosis is a global health problem. Mexico is one of the main countries affected; timely diagnosis and serological tests are the basis for detection. AIM: To know the frequency of confirmed cases of brucellosis in different of Family Medicine Units of the Mexican Social Security Institute in the state of Puebla, Mexico. METHODS: Cross-sectional study in patients of both genders, adults and pediatrics, with clinical manifestations suggestive of brucellosis; serological tests were performed for the confirmatory diagnosis. RESULTS: Out of a total of 77 patients, 39 (50.6%) were positive, 21 (27.3%) cases coming out of infection, 9 (11.7%) were negative and 8 (10.4%) were defined with immunological memory; of positive cases, 32 (82.1%) were found in the adult group and 30 (76.9%) were female. CONCLUSION: Around half of samples were confirmed as brucellosis, the clinical manifestations of the patients studied were non-specific, which highlights the importance of laboratory diagnosis.


Assuntos
Brucella , Brucelose , Adulto , Brucelose/diagnóstico , Brucelose/epidemiologia , Criança , Estudos Transversais , Feminino , Humanos , Masculino , México/epidemiologia , Testes Sorológicos
20.
Pharmaceutics ; 13(1)2020 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-33375069

RESUMO

The main goal of this work is the study of the skin wound healing efficacy of an antioxidant cocktail consisting of vitamins A, D, E and the endogenous pineal hormone melatonin (MLT), with all of these loaded into a thermosensitive hydrogel delivery system. The resulting formulation was characterized by scanning electron microscopy. The antioxidant efficacy and microbiological activity against Gram positive and Gram negative strains were also assayed. The skin healing efficacy was tested using an in vivo model which included histological evaluation. Furthermore, atomic force microscopy was employed to evaluate the wound healing efficacy of rat skin burns through the determination of its elasticity at the nanoscale using force spectroscopy analysis. The resulting hydrogel exhibited sol state at low temperature and turned into a gel at 30 ± 0.2 °C. The hydrogel containing the antioxidant cocktail showed higher scavenging activity than the hydrogel containing vitamins or MLT, separately. The formulation showed optimal antimicrobial activity. It was comparable to a commercial reference. It was also evidenced that the hydrogel containing the antioxidant cocktail exhibited the strongest healing process in the skin burns of rats, similar to the assayed commercial reference containing silver sulfadiazine. Histological studies confirmed the observed results. Finally, atomic force microscopy demonstrated a similar distribution of Young's modulus values between burned skin treated with the commercial reference and burned skin treated with hydrogel containing the antioxidant cocktail, and all these with healthy skin. The use of an antioxidant cocktail of vitamins and MLT might be a promising treatment for skin wounds for future clinical studies.

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