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1.
J Glob Antimicrob Resist ; 25: 107-109, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33662646

RESUMEN

OBJECTIVES: To determine the draft genome sequence and analyse the genetic features of a Staphylococcus pseudintermedius clinical isolate according to the main typing schemes available, with a special focus on antibiotic resistance. METHODS: The strain was isolated from a case of otitis externa in a dog. Its identity and pattern of antibiotic susceptibility were determined using an automated system. The genome was sequenced using an Illumina platform. MLST, SCCmec typing, resistome, and mobile genetic elements were derived by comparative analysis using available specific databases. RESULTS: S. pseudintermedius CAM1 isolate has a chromosome size of 2 652 610 bp. It showed a wide pattern of phenotypic resistance, comprising beta-lactams, macrolides and lincosamides, aminoglycosides, fluoroquinolones, tetracyclines, and trimethoprim-sulfamethoxazole. The genetic determinants of the underlying mechanisms were all found by in silico analysis of the genome. The mecA gene for methicillin resistance was harboured by the Vc type of the SCCmec. MLST of the strain was st551. CONCLUSION: By comparison with the MLST database of S. pseudintermedius and data from published molecular epidemiology studies, CAM1 is the first st551 strain recorded in Italy and, in the context of an already extremely wide antibiotic resistance pattern, it harbours also the tetK gene, the prevalence of which is rare in MDR S. pseudintermedius.


Asunto(s)
Otitis Externa , Preparaciones Farmacéuticas , Infecciones Estafilocócicas , Animales , Perros , Humanos , Italia , Tipificación de Secuencias Multilocus , Otitis Externa/veterinaria , Infecciones Estafilocócicas/veterinaria , Staphylococcus
2.
Food Res Int ; 133: 109128, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32466943

RESUMEN

The research of value-added applications for coffee silverskin (CSS) requires studies to investigate potential bioactive compounds and biological activities in CSS extracts. In this study, different ultrasound-assisted extraction (UAE) methods have been tested to extract bioactive compounds from CSS. The obtained extracts, were characterized using a new HPLC-MS/MS method to detect and quantify 30 bioactive compounds of 2 classes: alkaloids and polyphenols (including phenolic acids, flavonoids, and secoiridoids). CSS extracts obtained with ethanol/water (70:30) as extraction solvent showed the highest levels (p ≤ 0.05) of bioactive compounds (4.01 ± 0.34% w/w). High content of caffeine was observed with levels varying from 1.00% to 3.59% of dry weight of extract (dw). 18 phenolic compounds were detected in CSS extracts with caffeoylquinic acids (3-CQA, 5-CQA and 3,5-diCQA) as the most abundant polyphenols (3115.6 µg g to -5444.0 µg g-1). This study is also one of the first to characterize in-depth flavonoids in CSS revealing the levels of different flavonoids compounds such as rutin (1.63-8.70 µg g-1), quercetin (1.53-2.46 µg g-1), kaempferol (0.76-1.66 µg g-1) and quercitrin (0.15-0.51 µg g-1). Neuroprotective activity of silverskin extracts against H2O2-induced damage was evaluated for the first time suggesting for methanol and ethanol/water (70:30) extracts a potential role as protective agents against neurodegeneration due to their ability to counteract oxidative stress and maintain cell viability. Silverskin extracts were not inhibiting the growth of anyone of the bacterial species included in this study but data obtained by water extract might deserve a deeper future investigation on biofilm-related activities, such as quorum sensing or virulence factors' expression. From their composition and their evidenced biological activities, CSS extracts could represent valuable ingredients in nutraceutical formulations.


Asunto(s)
Antibacterianos/farmacología , Antioxidantes/farmacología , Café/química , Fitoquímicos/farmacología , Extractos Vegetales/farmacología , Cromatografía Líquida de Alta Presión , Espectrometría de Masas en Tándem
3.
Food Chem Toxicol ; 140: 111312, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32247803

RESUMEN

Since time immemorial, the oleo-gum-resins of Ferula assa-foetida and F. gummosa are used in the traditional medical systems as well as in foodstuffs, perfumery and cosmetics. In the present study, we explored the insecticidal efficacy of the essential oils obtained from these oleo-gum-resins to widen their fields of industrial applications. The two essential oils were mainly composed of sulfides [sec-butyl (Z)-propenyl disulfide, sec-butyl (E)-propenyl disulfide, sec-butyl (Z)-propenyl trisulfide and sec-butyl (E)-propenyl trisulfide)] and monoterpenes (α-pinene, ß-pinene and ß-phellandrene), respectively, as determined by GC-MS analysis. The two essential oils were assayed for toxicity on a panel of insects, represented by species of public health relevance (Culex quinquefasciatus and Musca domestica), agricultural (Spodoptera littoralis) and stored-product pests (Prostephanus truncatus and Trogoderma granarium). The ecotoxicological effects of the essential oils were assessed on the aquatic microcrustacean Daphnia magna and the earthworm Eisenia fetida, as well as on human cells. Overall, the two essential oils were effective against important insect pests and vectors. On the other hand, they resulted cytotoxic to fibroblasts and non-target aquatic microcrustaceans. Thus, further insights are needed to determine the full spectrum of their eco-toxicological effects.


Asunto(s)
Ferula/química , Insectos/efectos de los fármacos , Insecticidas/farmacología , Aceites Volátiles/farmacología , Aceites de Plantas/farmacología , Animales , Cromatografía de Gases y Espectrometría de Masas , Insecticidas/toxicidad , Aceites Volátiles/toxicidad , Aceites de Plantas/toxicidad
4.
Environ Sci Pollut Res Int ; 26(29): 30485-30497, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31444719

RESUMEN

Liriodendron tulipifera L. (Magnoliaceae), also known as "tulip tree," is a hardwood plant native to North America, cultivated all over the world and used on an industrial level, especially for its fine wood and to make honey. It has also been traditionally exploited for its antimalarial properties. However, our knowledge about the bioactivity of its essential oil remains patchy. In this research, we focused on the biological evaluation of the volatile fractions obtained from different parts of the plant which are normally discharged by industry, including leaves, flowers, and fruits. For the purpose, the essential oils were obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS). Then, they were evaluated as radical scavenging, antioxidant, antimicrobial, and antiproliferative agents by using DPPH, ABTS, FRAP, disk diffusion, and MTT methods, respectively. The significant toxicity exhibited on human tumor cells, namely A375 malignant melanoma, HCT116 colon carcinoma, MDA-MB 231 breast adenocarcinoma, and T98G glioblastoma multiforme cell lines, prompted us to study the mechanism of action by acridine orange/ethidium bromide double staining and caspase 3 assays. Our findings shed light on the potential applications of tulip tree derivatives as anticancer drugs.


Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Glioblastoma/tratamiento farmacológico , Liriodendron/química , Aceites Volátiles/farmacología , Aceites de Plantas/farmacología , Antiinfecciosos/farmacología , Antineoplásicos Fitogénicos/química , Antioxidantes/farmacología , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Evaluación Preclínica de Medicamentos , Flores/química , Cromatografía de Gases y Espectrometría de Masas , Glioblastoma/patología , Humanos , Pruebas de Sensibilidad Microbiana , Aceites Volátiles/química , Hojas de la Planta/química , Aceites de Plantas/química , Plantas Medicinales/química
5.
Microbiol Res ; 209: 79-85, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29580624

RESUMEN

Streptococcus mutans, a dental caries causing odontopathogen, produces X-prolyl dipeptidyl peptidase (Sm-XPDAP, encoded by pepX), a serine protease known to have a nutritional role. Considering the potential of proteases as therapeutic targets in pathogens, this study was primarily aimed at investigating the role of Sm-XPDAP in contributing to virulence-related traits. Dipeptidyl peptidase (DPP IV), an XPDAP analogous enzyme found in mammalian tissues,is a well known therapeutic target in Type II diabetes. Based on the hypothesis that gliptins, commonly used as anti-human-DPP IV drugs, may affect bacterial growth upon inhibition of Sm-XPDAP, we have determined their ex vivo antimicrobial and anti-biofilm activity towards S. mutans. All three DPP IV drugs tested reduced biofilm formation as determined by crystal violet staining. To link the observed biofilm inhibition to the human-DPP IV analogue present in S. mutans UA159, a pepX isogenic mutant was generated. In addition to reduced biofilm formation, CLSM studies of the biofilm formed by the pepX isogenic mutant showed these were comparable to those formed in the presence of saxagliptin, suggesting a probable role of this enzyme in biofilm formation by S. mutans UA159. The effects of both pepX deletion and DPP IV drugs on the proteome were studied using LC-MS/MS. Overall, this study highlights the potential of Sm-XPDAP as a novel anti-biofilm target and suggests a template molecule to synthesize lead compounds effective against this enzyme.


Asunto(s)
Biopelículas/crecimiento & desarrollo , Caries Dental/prevención & control , Dipeptidil-Peptidasas y Tripeptidil-Peptidasas/metabolismo , Streptococcus mutans/genética , Streptococcus mutans/patogenicidad , Adamantano/análogos & derivados , Adamantano/metabolismo , Antibacterianos/farmacología , Caries Dental/microbiología , Dipéptidos/metabolismo , Inhibidores de la Dipeptidil-Peptidasa IV/farmacología , Dipeptidil-Peptidasas y Tripeptidil-Peptidasas/genética , Pruebas de Sensibilidad Microbiana , Proteómica , Virulencia/genética
6.
J Med Microbiol ; 66(8): 1196-1201, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28786785

RESUMEN

PURPOSE: The presence of Staphylococcus aureus in poultry and poultry products, including eggs, increases its potential to enter the food chain, resulting in foodborne diseases. In this context, eggshell colonization by staphylococci may represent a risk factor. This study aimed to investigate the contamination of rural eggshell by S. aureus and to characterize the key features of the isolated strains. METHODOLOGY: Antibiotic resistance was assessed by disc diffusion. Resistant isolates were analysed by PCR for the identification of associated genetic determinants of resistance. PCR was also used to screen for the presence of genes coding for toxins, namely, sea, sec, sei, sem, seo and tst. The genetic characterization was extended by means of agr locus typing and spa typing. RESULTS: 34 S. aureus were isolated. Macrolide- and tetracycline-resistant strains were prevalent. All strains were susceptible to oxacillin, cefoxitin and trimethoprim-sulfamethoxazole. PCR screening for genes encoding enterotoxins detected several virulence patterns, which, together with spa-typing and agr-locus typing, allowed cluster analysis and the description of novel clones. CONCLUSION: Continuous monitoring of staphylococci is needed also in rural or natural settings. Increasing the number of samples and expanding the geographical region will be needed to further extend the significance of the study.


Asunto(s)
Cáscara de Huevo/microbiología , Enfermedades de las Aves de Corral/microbiología , Infecciones Estafilocócicas/veterinaria , Staphylococcus aureus/aislamiento & purificación , Animales , Antibacterianos/farmacología , Pollos , Farmacorresistencia Bacteriana , Humanos , Macrólidos/farmacología , Pruebas de Sensibilidad Microbiana , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/clasificación , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/genética , Tetraciclina/farmacología
7.
Food Chem ; 230: 24-29, 2017 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-28407906

RESUMEN

Ziziphus jujuba Mill., jujube, leaf infusions are popular bedtime beverages as they improve sleep by soothing the nerves. With the aim of providing further insights into the polyphenol content of jujube leaf infusion and their antioxidant activities, a 2,2-diphenyl-1-picrylhydrazyl (DPPH)-guided purification of the aqueous extract of Z. jujuba Mill. leaves was conducted. Three major antioxidant polyphenols (i.e. quercitrin, catechin and gallocatechin) of the leaves were identified. In addition, a significant antibiofilm bioactivity against Streptococcus mutans, a causative agent of human dental caries, was detected for the aqueous leaf extract and its bio-guided separation resulted in the identification of the lupane triterpenoid alphitolic acid as the main antibiofilm metabolite. The results herein presented further promote the consumption of jujube leaf infusion as a healthy antioxidant bedtime beverage, and associate it to an unreported anti-caries activity.


Asunto(s)
Antibacterianos/farmacología , Flavonoides/análisis , Hojas de la Planta/química , Streptococcus mutans/efectos de los fármacos , Triterpenos/farmacología , Ziziphus/química , Antioxidantes/análisis , Caries Dental/microbiología , Humanos , Extractos Vegetales/química , Hojas de la Planta/metabolismo , Triterpenos/análisis
8.
Nat Prod Res ; 31(10): 1121-1130, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-27562017

RESUMEN

The genus Thymus includes several species that are used as flavouring, food preservative as well as in cosmetics. Their secondary metabolites have been extensively studied for pharmacological effects. Nonetheless, some species are neglected and deserve to be explored for chemical composition and biological activities. This is the case with Thymus alternans, a Carpathian bush used as a food additive and for the preparation of a traditional herbal medicine. In this work, we have analysed the chemical composition of T. alternans essential oil by GC and GC-MS and evaluated its antimicrobial and antioxidant activity by disc diffusion, DPPH, ABTS and FRAP methods, respectively. Results showed that T. alternans belongs to the nerolidol chemotype, being rich of this sesquiterpene alcohol (15.8%) which might contribute to the antimicrobial (particularly effective on C. albicans growth) and antioxidant (weak inhibition on ABTS radical and reducing power) activities observed.


Asunto(s)
Antiinfecciosos/farmacología , Antioxidantes/farmacología , Aceites Volátiles/farmacología , Thymus (Planta)/química , Antifúngicos/farmacología , Bacterias/efectos de los fármacos , Benzotiazoles , Compuestos de Bifenilo , Candida albicans/efectos de los fármacos , Cromatografía de Gases y Espectrometría de Masas , Italia , Pruebas de Sensibilidad Microbiana , Picratos , Sesquiterpenos/química , Ácidos Sulfónicos
9.
Chem Biodivers ; 14(3)2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27685426

RESUMEN

Thymus munbyanus subsp. coloratus (Lamiaceae) is a small shrub endemic to Algeria and Morocco where is found in lawns, rockeries and mountainous regions. From a phytochemical point of view this taxon has never been characterized. In this work we have analysed the chemical compositions of the essential oils obtained from inflorescences and vegetative parts by GC/MS. A new chemotype, i.e. borneol-chemotype, was characterized for the first time in the species. Furthermore, we assessed the biological activities of essential oils, namely the antioxidant, antimicrobial and cytotoxicity on tumor cells that were evaluated by the DPPH, ABTS, and FRAP, disc diffusion, and MTT methods, respectively. Biological assays highlighted a moderate inhibitory effect on Staphylococcus aureus, Escherichia coli and Candida albicans (inhibition zone diameter in the range 9 - 10 mm), and noteworthy cytotoxicity on A375 human melanoma cells (IC50 of 46.95 µg/ml).


Asunto(s)
Antineoplásicos Fitogénicos/química , Lamiaceae/química , Aceites Volátiles/química , Aceites Volátiles/farmacología , Thymus (Planta)/química , Argelia , Antiinfecciosos/química , Antiinfecciosos/farmacología , Antineoplásicos Fitogénicos/farmacología , Antioxidantes/química , Candida albicans/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Cromatografía de Gases y Espectrometría de Masas , Lamiaceae/metabolismo , Pruebas de Sensibilidad Microbiana , Aceites Volátiles/análisis , Componentes Aéreos de las Plantas/química , Componentes Aéreos de las Plantas/metabolismo , Staphylococcus aureus/efectos de los fármacos , Thymus (Planta)/metabolismo
10.
Food Chem ; 218: 78-88, 2017 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-27719960

RESUMEN

Rosmarinus eriocalyx is an aromatic evergreen bush endemic to Algeria where it is used as a condiment to flavour soups and meat and as a traditional remedy. In the present work we have analyzed for the first time the phenolic composition of polar extracts obtained from stems, leaves and flowers of R. eriocalyx by HPLC, and determined the antioxidant and antimicrobial effects by DPPH, ABTS, FRAP, ORAC and agar disc diffusion methods, respectively. Results showed that ethanolic extracts of leaves and flowers are a rich source of phenolic compounds, mainly rosmarinic acid, carnosic acid and carnosol that are the main responsible for the noteworthy antioxidant activity observed in the assays. This study showed that R. eriocalyx might be a spice to be included in the European food additive list and used as a preservative agent besides R. officinalis.


Asunto(s)
Antioxidantes/aislamiento & purificación , Extractos Vegetales/aislamiento & purificación , Rosmarinus/química , Argelia , Antioxidantes/química , Cromatografía Líquida de Alta Presión/métodos , Cinamatos/química , Cinamatos/aislamiento & purificación , Depsidos/química , Depsidos/aislamiento & purificación , Flores/química , Aditivos Alimentarios/análisis , Aceites Volátiles/química , Aceites Volátiles/aislamiento & purificación , Extractos Vegetales/química , Hojas de la Planta/química , Tallos de la Planta/química , Polifenoles/química , Polifenoles/aislamiento & purificación , Ácido Rosmarínico
11.
Nat Prod Res ; 31(5): 515-522, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27266725

RESUMEN

Schizogyne sericea, well-known as 'salado', is a halophytic shrub widespread on coastal rocks of Tenerife (Canary Islands). This plant is used traditionally as analgesic, astringent, anti-inflammatory and vulnerary agent. In the present work, we have analysed the aqueous and ethanolic extracts of S. sericea for the content of phenolic acids by HPLC-DAD. The dynamic solid-liquid Naviglio® extractor was used to extract the flowering aerial parts. Aqueous extracts showed higher levels of phenolics than ethanolic extracts. S. sericea extracts were rich in chlorogenic and isochlorogenic acids. The Naviglio® extracts obtained were assayed for in vitro biological activities, namely antioxidant, antimicrobial and cytotoxicity on tumour cells by DPPH, ABTS, FRAP, agar disc-diffusion and MTT methods, respectively. Results showed that aqueous extracts, being richer in phenolic acids, are endowed with relevant radical scavenging activity (TEAC values in the range 208-960 µmol TE/g) while ethanolic extracts exhibited noteworthy antiproliferative effects on tumour cells.


Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Antioxidantes/farmacología , Asteraceae/química , Hidroxibenzoatos/análisis , Extractos Vegetales/farmacología , Línea Celular Tumoral , Humanos
12.
Springerplus ; 5(1): 1794, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27795936

RESUMEN

Our study focuses on the antimicrobial susceptibility, genotypic and phenotypic heterogeneity, and serotype classification of the Streptococcus mutans isolated from type II diabetic patients (n = 25; age 42-68). Eighty-two percent of isolates were classified as serotype c. No serotype k was present. Macrorestriction analysis of genomic DNA of the isolates exhibited a clonal diversity that paralleled the phenotypic heterogeneity, which was also assessed in terms of biofilm forming ability. Isolates were susceptible to all the classes of antibiotics. In conclusion a great heterogeneity and no antimicrobial resistance were apparent in the considered S. mutans strains from diabetic patients.

13.
Molecules ; 21(8)2016 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-27529211

RESUMEN

Erigeron floribundus (Asteraceae) is an herbaceous plant widely used in Cameroonian traditional medicine to treat various diseases of microbial and non-microbial origin. In the present study, we evaluated the in vitro biological activities displayed by the essential oil obtained from the aerial parts of E. floribundus, namely the antioxidant, antimicrobial and antiproliferative activities. Moreover, we investigated the inhibitory effects of E. floribundus essential oil on nicotinate mononucleotide adenylyltransferase (NadD), a promising new target for developing novel antibiotics, and Trypanosoma brucei, the protozoan parasite responsible for Human African trypanosomiasis. The essential oil composition was dominated by spathulenol (12.2%), caryophyllene oxide (12.4%) and limonene (8.8%). The E. floribundus oil showed a good activity against Staphylococcus aureus (inhibition zone diameter, IZD of 14 mm, minimum inhibitory concentration, MIC of 512 µg/mL). Interestingly, it inhibited the NadD enzyme from S. aureus (IC50 of 98 µg/mL), with no effects on mammalian orthologue enzymes. In addition, T. brucei proliferation was inhibited with IC50 values of 33.5 µg/mL with the essential oil and 5.6 µg/mL with the active component limonene. The essential oil exhibited strong cytotoxicity on HCT 116 colon carcinoma cells with an IC50 value of 14.89 µg/mL, and remarkable ferric reducing antioxidant power (tocopherol-equivalent antioxidant capacity, TEAC = 411.9 µmol·TE/g).


Asunto(s)
Erigeron/química , Aceites Volátiles/farmacología , Animales , Antiinfecciosos/química , Antiinfecciosos/farmacología , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/farmacología , Antioxidantes/química , Antioxidantes/farmacología , Bacterias/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Humanos , Concentración 50 Inhibidora , Ratones , Pruebas de Sensibilidad Microbiana , Aceites Volátiles/química , Extractos Vegetales/química , Extractos Vegetales/farmacología
14.
Chem Biodivers ; 13(7): 826-36, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27272544

RESUMEN

Schizogyne sericea (Asteraceae) is a halophytic shrub endemic to the Canary Islands and traditionally employed as analgesic, astringent, anti-inflammatory, and vulnerary. A comprehensive phytochemical investigation was conducted on the flowering aerial parts by analyzing both essential oil constituents and polar compounds. The essential oil was dominated by p-cymene, with the noteworthy occurrence of ß-pinene and thymol esters. From the EtOH extract, eight compounds were isolated and structurally elucidated. Essential oil, polar fractions, and isolates (2), (4), and (5) were separately in vitro assayed for antiproliferative activity on human tumor cell lines (A375, MDA-MB 231, and HCT116) by MTT assay, for antioxidant potential by DPPH, ABTS, and FRAP assays, and for antimicrobial activity by the agar disk diffusion method. Results revealed that essential oil and compounds 1 and 2 exert a strong inhibition on tumor cells, and in some cases, higher than that of cisplatin. Fractions containing thymol derivatives (1 and 2) and caffeoylquinic acid derivatives 4 and 5 displayed antioxidant activity comparable to that of Trolox, making S. sericea extract an interesting natural product with potential applications as preservative or in the treatment of diseases in which oxidative stress plays an important role.


Asunto(s)
Antibacterianos/farmacología , Antifúngicos/farmacología , Antineoplásicos Fitogénicos/farmacología , Antioxidantes/farmacología , Asteraceae/química , Asteraceae/metabolismo , Aceites Volátiles/farmacología , Fenoles/farmacología , Metabolismo Secundario , Antibacterianos/análisis , Antibacterianos/metabolismo , Antifúngicos/análisis , Antifúngicos/metabolismo , Antineoplásicos Fitogénicos/análisis , Antineoplásicos Fitogénicos/metabolismo , Antioxidantes/análisis , Antioxidantes/metabolismo , Bacterias/efectos de los fármacos , Bacterias/crecimiento & desarrollo , Candida albicans/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Humanos , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Aceites Volátiles/análisis , Aceites Volátiles/metabolismo , Fenoles/análisis , Fenoles/metabolismo , España , Relación Estructura-Actividad
15.
mBio ; 7(3)2016 05 31.
Artículo en Inglés | MEDLINE | ID: mdl-27247229

RESUMEN

UNLABELLED: For over a century, a fundamental objective in infection biology research has been to understand the molecular processes contributing to the origin and perpetuation of epidemics. Divergent hypotheses have emerged concerning the extent to which environmental events or pathogen evolution dominates in these processes. Remarkably few studies bear on this important issue. Based on population pathogenomic analysis of 1,200 Streptococcus pyogenes type emm89 infection isolates, we report that a series of horizontal gene transfer events produced a new pathogenic genotype with increased ability to cause infection, leading to an epidemic wave of disease on at least two continents. In the aggregate, these and other genetic changes substantially remodeled the transcriptomes of the evolved progeny, causing extensive differential expression of virulence genes and altered pathogen-host interaction, including enhanced immune evasion. Our findings delineate the precise molecular genetic changes that occurred and enhance our understanding of the evolutionary processes that contribute to the emergence and persistence of epidemically successful pathogen clones. The data have significant implications for understanding bacterial epidemics and for translational research efforts to blunt their detrimental effects. IMPORTANCE: The confluence of studies of molecular events underlying pathogen strain emergence, evolutionary genetic processes mediating altered virulence, and epidemics is in its infancy. Although understanding these events is necessary to develop new or improved strategies to protect health, surprisingly few studies have addressed this issue, in particular, at the comprehensive population genomic level. Herein we establish that substantial remodeling of the transcriptome of the human-specific pathogen Streptococcus pyogenes by horizontal gene flow and other evolutionary genetic changes is a central factor in precipitating and perpetuating epidemic disease. The data unambiguously show that the key outcome of these molecular events is evolution of a new, more virulent pathogenic genotype. Our findings provide new understanding of epidemic disease.


Asunto(s)
Proteínas Bacterianas/genética , Epidemias , Interacciones Huésped-Patógeno , Infecciones Estreptocócicas/epidemiología , Infecciones Estreptocócicas/microbiología , Streptococcus pyogenes/genética , Transcriptoma , Epidemias/prevención & control , Evolución Molecular , Transferencia de Gen Horizontal , Genoma Bacteriano , Genotipo , Humanos , Evasión Inmune , Polimorfismo de Nucleótido Simple , Recombinación Genética , Streptococcus pyogenes/inmunología , Streptococcus pyogenes/patogenicidad , Virulencia/genética , Factores de Virulencia/genética
16.
Food Funct ; 7(4): 1892-903, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27040352

RESUMEN

In the present work we conducted a comprehensive chemical analysis of blue honeysuckle (Lonicera caerulea) spontaneously growing in eastern Russia. HPLC-DAD-ESI/MS analysis showed cyanidin-3-glucoside as the major constituent among phenolics, while nutritional analysis revealed fibre, protein, calcium and magnesium as the most important macro- and micronutrients, respectively. Fatty acid composition was dominated by polyunsaturated fatty acids, linoleic acid being the most abundant. Furthermore, we evaluated several in vitro biological activities such as antioxidant, antimicrobial, antiproliferative, wound healing and immunomodulatory effects of blue honeysuckle aqueous and ethanolic extracts that are often incorporated in food and nutraceutical preparations. While the fruit extracts were revealed to be potent radical scavengers with significant inhibition of ABTS radical, thus confirming the literature data, their inhibitory effects against microbial pathogens and tumor cell lines were negligible. The fruit aqueous extract did not show toxicity to human fibroblasts, but 24 h treatment with 150-200 µg per mL of extract slightly enhanced the cell migration when tested by scratched wound assay. Worth mentioning was the inhibitory effect displayed by the blue honeysuckle fruit aqueous extract on human lymphocytes.


Asunto(s)
Lonicera/química , Extractos Vegetales/química , Extractos Vegetales/farmacología , Polifenoles/química , Polifenoles/farmacología , Antiinfecciosos/química , Antiinfecciosos/farmacología , Antioxidantes/química , Antioxidantes/farmacología , Línea Celular , Supervivencia Celular/efectos de los fármacos , Frutas/química , Humanos , Valor Nutritivo , Federación de Rusia
17.
FEMS Microbiol Lett ; 363(9)2016 05.
Artículo en Inglés | MEDLINE | ID: mdl-27010012

RESUMEN

Streptococcus mutans harbours an intracellular, human DPP IV-analogous enzyme Xaa-Pro dipeptidyl-peptidase (EC 3.4.14.11). According to previous reports, an extracellular isozyme in S. gordonii and S. suis has been associated with virulence. Speculating that even an intracellular form may aid in virulence of S. mutans, we have tried to purify, characterize and evaluate enzyme inhibition by specific inhibitors. The native enzyme was partially purified by ion-exchange and gel filtration chromatography. Owing to low yield, the enzyme was overexpressed in Lactococcus lactis and purified by affinity chromatography. The recombinant enzyme (rSm-XPDAP) had a specific activity of 1070 U mg(-1), while the Vmax and Km were 7 µM min(-1) and 89 ± 7 µM (n = 3), respectively. The serine protease inhibitor phenylmethylsulphonyl fluoride and a DPP IV-specific inhibitor diprotin A proved to be active against rSm-XPDAP. As a novel approach, the evaluation of the effect of anti-human DPP IV (AHD) drugs on rSm-XPDAP activity found saxagliptin to be effective to some extent (Ki = 129 ± 16 µM), which may lead to the synthesis and development of a new class of antimicrobial agents.


Asunto(s)
Inhibidores de la Dipeptidil-Peptidasa IV/farmacología , Dipeptidil-Peptidasas y Tripeptidil-Peptidasas/antagonistas & inhibidores , Dipeptidil-Peptidasas y Tripeptidil-Peptidasas/genética , Streptococcus mutans/enzimología , Streptococcus mutans/genética , Adamantano/análogos & derivados , Adamantano/farmacología , Secuencia de Aminoácidos , Cromatografía en Gel , Clonación Molecular , Dipéptidos/farmacología , Dipeptidil Peptidasa 4/metabolismo , Dipeptidil-Peptidasas y Tripeptidil-Peptidasas/química , Dipeptidil-Peptidasas y Tripeptidil-Peptidasas/metabolismo , Humanos , Concentración de Iones de Hidrógeno , Cinética , Lactococcus lactis/genética , Oligopéptidos/farmacología , Proteínas Recombinantes/química , Proteínas Recombinantes/aislamiento & purificación , Proteínas Recombinantes/metabolismo , Alineación de Secuencia , Streptococcus mutans/efectos de los fármacos , Especificidad por Sustrato
18.
Nat Prod Res ; 30(16): 1802-9, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26343516

RESUMEN

The purpose of this study was to investigate the composition of the essential oil obtained from a population of Artemisia caerulescens subsp. densiflora growing in Razzoli, an island in the La Maddalena Archipelago (Sardinia, Italy). A. caerulescens sups. densiflora Viv. (Asteraceae), a wild herb, seldom studied in the Mediterranean, represents one of the many rare endemic species growing in North Sardinia. The essential oil composition was analysed by means of GC/MS analysis, which showed davana ethers as the major volatile components, accounting together for 17.5%, followed by (E)-nerolidol (4.5%), ß-oplopenone (3.3%), cis-sabinene hydrate (5.2%) and terpinen-4-ol (4.7%). The oil was tested for antioxidant activity by means of DPPH test, inhibition of lipid oxidation test and hypochlorous acid test, which showed a quite interesting scavenger capacity. For the first time, we reported the cytotoxic activity of the essential oil of A. caerulescens subsp. densiflora, against three human tumour cell lines (A375, MDA-MB231 and HCT116), with IC50 values in the range 5.20-7.61 µg/mL, which deserved further studies to support its use as chemopreventive agent. Finally, the antimicrobial activity of the essential oil, displayed on a panel of human pathogens, was very low.


Asunto(s)
Artemisia/química , Asteraceae/química , Aceites Volátiles/química , Antiinfecciosos , Antineoplásicos/química , Antineoplásicos/farmacología , Antioxidantes , Línea Celular Tumoral , Ecosistema , Cromatografía de Gases y Espectrometría de Masas , Humanos , Concentración 50 Inhibidora , Italia , Aceites Volátiles/farmacología , Terpenos/química
19.
Fitoterapia ; 100: 95-109, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25464055

RESUMEN

In the present work we carried out a phytochemical and biological investigation on three Hypericum species, i.e. Hypericum reflexum, Hypericum canariense and Hypericum grandifolium, from the Canary Islands where they are traditionally used as diuretic, wound healing, vermifuge, sedative and antidepressive agents. The polar extracts of the top flowering aerial parts, prepared by Soxhlet apparatus using a methanol-acetone (1:1) extracting mixture, were analyzed by HPLC-DAD and HPLC-MS for the content of eight biomarkers such as hypericin, hyperforin, chlorogenic acid, rutin, hyperoside, isoquercitrin, quercitrin and quercetin, whereas the hydrodistilled essential oils were analyzed by GC-FID and GC-MS. The three Hypericum species had different results in both polar and volatile constituents, H. reflexum being the only one endowed with a small amount of naphtodianthrones (hypericin and pseudohypericin), and containing high levels of chlorogenic acid, rutin and volatile mono- and sesquiterpenes. After chemical characterization, all products were in vitro biologically assayed for antiproliferative activity on human tumor cell lines by MTT assay, for antioxidant potential by DPPH, ABTS and FRAP assays, and for antimicrobial activity by the agar disc diffusion and microdilution methods. Results revealed interesting bioactivities and differences between polar extracts and essential oils, with the former being endowed with significant antioxidant activity and the latter with comparable inhibition effects on the tumor cells (A375, MDA-MB 231 and HCT 116) to that of cisplatin.


Asunto(s)
Hypericum/química , Fitoquímicos/farmacología , Extractos Vegetales/farmacología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Humanos , Aceites Volátiles/química , Aceites Volátiles/farmacología , Componentes Aéreos de las Plantas/química , Extractos Vegetales/química , España
20.
Inorg Chem ; 54(2): 434-40, 2015 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-25531979

RESUMEN

Two new silver(I) complexes of formula [Ag(mPTA)4](Tpms)4(BF4) (1) and [Ag(Tpms)(mPTA)](BF4) (2) (mPTA = N-methyl-1,3,5-triaza-7-phosphaadamantane cation, Tpms = tris(pyrazol-1-yl)methanesulfonate anion) have been synthesized and fully characterized by elemental analyses, (1)H and (31)P{(1)H} NMR, ESI-MS, and IR spectroscopic techniques. The single-crystal X-ray diffraction study of 1 discloses a noncoordinated nature of the Tpms species, existing as counterions around the highly charged metal center [Ag(mPTA)](5+), 1 being the first reported coordination compound bearing a κ(0)-Tpms. 1 features high solubility and stability in water (S25 °C ≈ 30 mg·mL(-1)). The two complexes interact with calf thymus DNA via intercalation mode, binding to the BSA with decrease of its tryptophan fluorescence with a static quenching mechanism. The two new silver complexes exhibit significant antibacterial and antifungal activities screened in vitro against the standard strains of Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans.


Asunto(s)
Adamantano/análogos & derivados , Luz , Compuestos Organometálicos/síntesis química , Compuestos Organometálicos/farmacología , Compuestos Organofosforados/química , Plata/química , Agua/química , Adamantano/química , Inhibidores de la Adenosina Desaminasa/síntesis química , Inhibidores de la Adenosina Desaminasa/química , Inhibidores de la Adenosina Desaminasa/metabolismo , Inhibidores de la Adenosina Desaminasa/farmacología , Animales , Antiinfecciosos/síntesis química , Antiinfecciosos/química , Antiinfecciosos/metabolismo , Antiinfecciosos/farmacología , Bacterias/efectos de los fármacos , Candida albicans/efectos de los fármacos , Bovinos , Técnicas de Química Sintética , Estabilidad de Medicamentos , Pruebas de Sensibilidad Microbiana , Modelos Moleculares , Conformación Molecular , Compuestos Organometálicos/química , Compuestos Organometálicos/metabolismo , Albúmina Sérica Bovina/metabolismo , Solubilidad
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