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1.
Molecules ; 26(15)2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-34361717

RESUMO

The development of bio-based nanocomposites is of high scientific and industrial interest, since they offer excellent advantages in creating functional materials. However, dispersion and distribution of the nanomaterials inside the polymer matrix is a key challenge to achieve high-performance functional nanocomposites. In this context, for better dispersion, biobased triethyl citrate (TEC) as a dispersing agent in a liquid-assisted extrusion process was used to prepare the nanocomposites of poly (lactic acid) (PLA) and chitin nanocrystals (ChNCs). The aim was to identify the effect of the TEC content on the dispersion of ChNCs in the PLA matrix and the manufacturing of a functional nanocomposite. The nanocomposite film's optical properties; microstructure; migration of the additive and nanocomposites' thermal, mechanical and rheological properties, all influenced by the ChNC dispersion, were studied. The microscopy study confirmed that the dispersion of the ChNCs was improved with the increasing TEC content, and the best dispersion was found in the nanocomposite prepared with 15 wt% TEC. Additionally, the nanocomposite with the highest TEC content (15 wt%) resembled the mechanical properties of commonly used polymers like polyethylene and polypropylene. The addition of ChNCs in PLA-TEC15 enhanced the melt viscosity, as well as melt strength, of the polymer and demonstrated antibacterial activity.


Assuntos
Antibacterianos/síntese química , Quitina/química , Citratos/química , Nanocompostos/química , Nanopartículas/química , Poliésteres/química , Antibacterianos/farmacologia , Módulo de Elasticidade , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Nanocompostos/ultraestrutura , Nanopartículas/ultraestrutura , Reologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Resistência à Tração , Viscosidade
2.
Molecules ; 26(16)2021 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-34443349

RESUMO

Ulva sp. is known to be a source of bioactive compounds such as ulvans, but to date, their biological activity on skin commensal and/or opportunistic pathogen bacteria has not been reported. In this study, the effects of poly- and oligosaccharide fractions produced by enzyme-assisted extraction and depolymerization were investigated, for the first time in vitro, on cutaneous bacteria: Staphylococcus aureus, Staphylococcus epidermidis, and Cutibacterium acnes. At 1000 µg/mL, poly- and oligosaccharide fractions did not affect the growth of the bacteria regarding their generation time. Polysaccharide Ulva sp. fractions at 1000 µg/mL did not alter the bacterial biofilm formation, while oligosaccharide fractions modified S. epidermidis and C. acnes biofilm structures. None of the fractions at 1000 µg/mL significantly modified the cytotoxic potential of S. epidermidis and S. aureus towards keratinocytes. However, poly- and oligosaccharide fractions at 1000 µg/mL induced a decrease in the inflammatory potential of both acneic and non-acneic C. acnes strains on keratinocytes of up to 39.8%; the strongest and most significant effect occurred when the bacteria were grown in the presence of polysaccharide fractions. Our research shows that poly- and oligosaccharide Ulva sp. fractions present notable biological activities on cutaneous bacteria, especially towards C. acnes acneic and non-acneic strains, which supports their potential use for dermo-cosmetic applications.


Assuntos
Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Microbiota/efeitos dos fármacos , Extratos Vegetais/farmacologia , Pele/microbiologia , Ulva/química , Bactérias/patogenicidade , Relação Dose-Resposta a Droga , Propionibacteriaceae/efeitos dos fármacos , Propionibacteriaceae/crescimento & desenvolvimento , Propionibacteriaceae/patogenicidade , Propionibacteriaceae/fisiologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus aureus/patogenicidade , Staphylococcus aureus/fisiologia , Staphylococcus epidermidis/efeitos dos fármacos , Staphylococcus epidermidis/crescimento & desenvolvimento , Staphylococcus epidermidis/patogenicidade , Staphylococcus epidermidis/fisiologia , Virulência/efeitos dos fármacos
3.
Molecules ; 26(16)2021 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-34443354

RESUMO

If plasma polymer thin films are to be synthesised from sustainable and natural precursors of chemically heterogeneous composition, it is important to understand the extent to which this composition influences the mechanism of polymerisation. To this end, a well-studied monoterpene alcohol, terpinen-4-ol, has been targeted for a comparative study with the naturally occurring mix of terpenes (viz. Melaleuca alternifolia oil) from which it is commonly distilled. Positive ion mode mass spectra of both terpinen-4-ol and M. alternifolia oil showed a decrease in disparities between the type and abundance of cationic species formed in their respective plasma environments as applied plasma power was increased. Supplementary biological assay revealed the antibacterial action of both terpinen-4-ol and M. alternifolia derived coatings with respect to S. aureus bacteria, whilst cytocompatibility was demonstrated by comparable eukaryotic cell adhesion to both coatings. Elucidating the processes occurring within the reactive plasmas can enhance the economics of plasma polymer deposition by permitting use of the minimum power, time and precursor pre-processing required to control the extent of monomer fragmentation and fabricate a film of the desired thickness and functionality.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Produtos Biológicos/química , Gases em Plasma/química , Staphylococcus aureus/efeitos dos fármacos , Terpenos/química , Terpenos/farmacologia , Melaleuca/química
4.
Molecules ; 26(16)2021 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-34443363

RESUMO

The antimicrobial properties of herbs from Papaveraceae have been used in medicine for centuries. Nevertheless, mutual relationships between the individual bioactive substances contained in these plants remain poorly elucidated. In this work, phytochemical composition of extracts from the aerial and underground parts of five Papaveraceae species (Chelidonium majus L., Corydalis cava (L.) Schweigg. and Körte, C. cheilanthifolia Hemsl., C. pumila (Host) Rchb., and Fumaria vaillantii Loisel.) were examined using LC-ESI-MS/MS with a triple quadrupole analyzer. Large differences in the quality and quantity of all analyzed compounds were observed between species of different genera and also within one genus. Two groups of metabolites predominated in the phytochemical profiles. These were isoquinoline alkaloids and, in smaller amounts, non-phenolic carboxylic acids and phenolic compounds. In aerial and underground parts, 22 and 20 compounds were detected, respectively. These included: seven isoquinoline alkaloids: protopine, allocryptopine, coptisine, berberine, chelidonine, sanguinarine, and chelerythrine; five of their derivatives as well as non-alkaloids: malic acid, trans-aconitic acid, quinic acid, salicylic acid, trans-caffeic acid, p-coumaric acid, chlorogenic acid, quercetin, and kaempferol; and vanillin. The aerial parts were much richer in phenolic compounds regardless of the plant species. Characterized extracts were studied for their antimicrobial potential against planktonic and biofilm-producing cells of S. aureus, P. aeruginosa, and C. albicans. The impact of the extracts on cellular metabolic activity and biofilm biomass production was evaluated. Moreover, the antimicrobial activity of the extracts introduced to the polymeric carrier made of bacterial cellulose was assessed. Extracts of C. cheilanthifolia were found to be the most effective against all tested human pathogens. Multiple regression tests indicated a high antimicrobial impact of quercetin in extracts of aerial parts against planktonic cells of S. aureus, P. aeruginosa, and C. albicans, and no direct correlation between the composition of other bioactive substances and the results of antimicrobial activity were found. Conclusively, further investigations are required to identify the relations between recognized and unrecognized compounds within extracts and their biological properties.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Produtos Biológicos/farmacologia , Papaveraceae/química , Extratos Vegetais/farmacologia , Antibacterianos/química , Biofilmes/crescimento & desenvolvimento , Produtos Biológicos/química , Avaliação Pré-Clínica de Medicamentos , Extratos Vegetais/química , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/fisiologia
5.
Molecules ; 26(16)2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34443590

RESUMO

Biocompatible skin wound dressing materials with long-term therapeutic windows and anti-infection properties have attracted great attention all over the world. The cooperation between essential oil and non-toxic or bio-based polymers was a promising strategy. However, the inherent volatility and chemical instability of most ingredients in essential oils make the sustained pharmacological activity of essential oil-based biomaterials a challenge. In this study, a kind of film nanocomposite loaded with patchouli essential oil (PEO-FNC) was fabricated. PEO-loaded mesoporous silica nanoparticles (PEO-MSNs) with drug load higher than 40 wt% were firstly prepared using supercritical CO2 cyclic impregnation (SCCI), and then combined with the film matrix consisting of polyvinyl alcohol and chitosan. The morphology of PEO-MSNs and PEO-FNC was observed by transmission and scanning electron microscope. The mechanical properties, including hygroscopicity, tensile strength and elongation at break (%), were tested. The release behavior of PEO from the film nanocomposite showed that PEO could keep releasing for more than five days. PEO-FNC exhibited good long-term (>48 h) antibacterial effect on Staphylococcus aureus and non-toxicity on mouse fibroblast (L929 cells), making it a promising wound dressing material.


Assuntos
Bandagens/microbiologia , Dióxido de Carbono/química , Nanocompostos/química , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Pogostemon/química , Cicatrização/efeitos dos fármacos , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Camundongos , Staphylococcus aureus/efeitos dos fármacos
6.
ACS Appl Mater Interfaces ; 13(33): 40013-40031, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34375080

RESUMO

Flexible and wearable hydrogel strain sensors have attracted tremendous attention for applications in human motion and physiological signal monitoring. However, it is still a great challenge to develop a hydrogel strain sensor with certain mechanical properties and tensile deformation capabilities, which can be in conformal contact with the target organ and also have self-healing properties, self-adhesive capability, biocompatibility, antibacterial properties, high strain sensitivity, and stable electrical performance. In this paper, an ionic conductive hydrogel (named PBST) is rationally designed by proportionally mixing polyvinyl alcohol (PVA), borax, silk fibroin (SF), and tannic acid (TA). SF can not only be a reinforcement to introduce an energy dissipation mechanism into the dynamically cross-linked hydrogel network to stabilize the non-Newtonian behavior of PVA and borax but it can also act as a cross-linking agent to combine with TA to reduce the dissociation of TA on the hydrogel network, improving the mechanical properties and viscoelasticity of the hydrogel. The combination of SF and TA can improve the self-healing ability of the hydrogel and realize the adjustable viscoelasticity of the hydrogel without sacrificing other properties. The obtained hydrogel has excellent stretchability (strain > 1000%) and shows good conformal contact with human skin. When the hydrogel is damaged by external strain, it can rapidly self-repair (mechanical and electrical properties) without external stimuli. It shows adhesiveness and repeatable adhesiveness to different materials (steel, wood, PTFE, glass, iron, and cotton fabric) and biological tissues (pigskin) and is easy to peel off without residue. The obtained PBST conductive hydrogel also has a wide strain-sensing range (>650%) and reliable stability. The hydrogel adhered to the skin surface can monitor large strain movements such as in finger joints, wrist joints, knee joints, and so on and detect swallowing, smiling, facial bulging and calming, and other micro-deformation behaviors. It can also distinguish physical signals such as light smile, big laugh, fast and slow breathing, and deep and shallow breathing. Therefore, the PBST conductive hydrogel material with multiple synergistic functions has great potential as a flexible wearable strain sensor. The PBST hydrogel has antibacterial properties and good biocompatibility at the same time, which provides a safety guarantee for it as a flexible wearable strain sensor. This work is expected to provide a new way for people to develop ideal wearable strain sensors.


Assuntos
Adesivos/química , Materiais Biocompatíveis/química , Fibroínas/química , Hidrogéis/química , Substâncias Viscoelásticas/química , Animais , Antibacterianos/química , Materiais Biocompatíveis/metabolismo , Boratos/química , Sobrevivência Celular/efeitos dos fármacos , Reagentes para Ligações Cruzadas/química , Condutividade Elétrica , Técnicas Eletroquímicas , Desenho de Equipamento/instrumentação , Desenho de Equipamento/métodos , Fibroblastos/citologia , Humanos , Hidrogéis/metabolismo , Camundongos , Monitorização Fisiológica/instrumentação , Monitorização Fisiológica/métodos , Movimento , Álcool de Polivinil/química , Reologia , Pele , Staphylococcus aureus/efeitos dos fármacos , Propriedades de Superfície , Taninos/química , Dispositivos Eletrônicos Vestíveis , Cicatrização
7.
Int J Mol Sci ; 22(15)2021 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-34360797

RESUMO

A novel series of N-substituted cis- and trans-3-aryl-4-(diethoxyphosphoryl)azetidin-2-ones were synthesized by the Kinugasa reaction of N-methyl- or N-benzyl-(diethyoxyphosphoryl)nitrone and selected aryl alkynes. Stereochemistry of diastereoisomeric adducts was established based on vicinal H3-H4 coupling constants in azetidin-2-one ring. All the obtained azetidin-2-ones were evaluated for the antiviral activity against a broad range of DNA and RNA viruses. Azetidin-2-one trans-11f showed moderate inhibitory activity against human coronavirus (229E) with EC50 = 45 µM. The other isomer cis-11f was active against influenza A virus H1N1 subtype (EC50 = 12 µM by visual CPE score; EC50 = 8.3 µM by TMS score; MCC > 100 µM, CC50 = 39.9 µM). Several azetidin-2-ones 10 and 11 were tested for their cytostatic activity toward nine cancerous cell lines and several of them appeared slightly active for Capan-1, Hap1 and HCT-116 cells values of IC50 in the range 14.5-97.9 µM. Compound trans-11f was identified as adjuvant of oxacillin with significant ability to enhance the efficacy of this antibiotic toward the highly resistant S. aureus strain HEMSA 5. Docking and molecular dynamics simulations showed that enantiomer (3R,4S)-11f can be responsible for the promising activity due to the potency in displacing oxacillin at ß-lactamase, thus protecting the antibiotic from undesirable biotransformation.


Assuntos
Adjuvantes Farmacêuticos/química , Adjuvantes Farmacêuticos/farmacologia , Antivirais/química , Antivirais/farmacologia , Azetidinas/farmacologia , Infecções/tratamento farmacológico , Antibacterianos/química , Antibacterianos/farmacologia , Azetidinas/química , Proteínas de Bactérias/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Coronavirus Humano 229E/efeitos dos fármacos , Citostáticos/química , Citostáticos/farmacologia , Humanos , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Simulação de Dinâmica Molecular , Oxacilina/química , Proteínas de Ligação às Penicilinas/química , Staphylococcus aureus/efeitos dos fármacos , Estereoisomerismo , beta-Lactamases/química
8.
Molecules ; 26(15)2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34361741

RESUMO

Due to their richness of bioactive substances, rose hips are a valuable raw material for obtaining extracts with potential antimicrobial activity. The aim of the study was to determine the antagonistic potential of whole pseudo-fruit and flesh extracts of three Rosa sp. varieties against Staphylococcus spp. bacteria isolated as food contaminants. The biological material in this study consisted of seven strains of bacteria from the genus Staphylococcus. Two strains-Staphylococcus aureus ATCC 25923 and Staphylococcus epidermidis DSMZ 3270-were used as reference strains. The other five strains were food-derived isolates-S. epidermidis A5, S. xylosus M5, S. haemolyticus M6, S. capitis KR6, and S. warneri KR2A. The material was the pseudo-fruits of Rosa canina, Rosa pomifera Karpatia, and Rosa rugosa. The polyphenols were extracted from the fleshy part and the whole pseudo-fruit for all rose varieties. The tested preparations differed significantly in their polyphenol composition. The sum of polyphenols ranged from 28 862 to 35 358 mg/100 g of lyophilisate. The main groups of polyphenols found in the preparations were flavanols and ellagitannins. All of the tested extracts inhibited the growth of staphylococci at a concentration of 500 mg/mL. Rosa rugosa fruit extract showed the strongest antimicrobial properties among the studied extracts. For all the strains, the growth inhibition had a diameter of 20.3-29.0 mm. Moreover, six out of the seven tested strains showed the highest inhibition with the use of this extract. The MIC of rose extracts was in the range of 3.125-500 mg/mL and was strictly dependent on the bacterial species, the species of the rose, and the part of the fruit from which the extract was obtained. Correlations were assessed between the main groups of polyphenols in the extracts and their inhibition of bacterial growth. In the case of pseudo-fruit extracts, the inhibitory effect on bacterial growth positively correlated with the content of ellagitannins, and this effect was observed for almost all the tested strains. The results presented herein follow the current trend of minimising the use of chemical preservatives in food; from this point of view, rose extracts are very promising.


Assuntos
Antibacterianos/química , Flavonoides/química , Taninos Hidrolisáveis/química , Polifenóis/química , Rosa/química , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Flavonoides/isolamento & purificação , Flavonoides/farmacologia , Contaminação de Alimentos/prevenção & controle , Microbiologia de Alimentos/métodos , Frutas/química , Humanos , Taninos Hidrolisáveis/isolamento & purificação , Taninos Hidrolisáveis/farmacologia , Testes de Sensibilidade Microbiana , Extratos Vegetais/química , Polifenóis/isolamento & purificação , Polifenóis/farmacologia , Staphylococcus/efeitos dos fármacos , Staphylococcus/crescimento & desenvolvimento , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus capitis/efeitos dos fármacos , Staphylococcus capitis/crescimento & desenvolvimento , Staphylococcus epidermidis/efeitos dos fármacos , Staphylococcus epidermidis/crescimento & desenvolvimento , Staphylococcus haemolyticus/efeitos dos fármacos , Staphylococcus haemolyticus/crescimento & desenvolvimento
9.
ACS Appl Mater Interfaces ; 13(33): 39806-39818, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34387459

RESUMO

Silver nanomaterials have attracted a great deal of interest due to their broad-spectrum antimicrobial activity. However, it is still challenging to balance the high antibacterial efficiency with low damage to biological cells of silver nanostructures, especially when the diameter decreases to less than 10 nm. Here, we developed a new type of Ag nanohybrid material via a unimolecular micelle template method, which presents amazing antibacterial activities and almost noncytotoxicity. First, water-soluble multiarm star-shaped brushlike copolymer α-CD-g-[(PEO40-g-PAA50)-b-PEO5]18 was precisely synthesized and its micelle behavior in different solvents was revealed. Then, nanocrystal clusters assembled by Ag grains (Ag@Template NCs) were prepared through an in situ redox route using the unimolecular micelle of α-CD-g-[(PEO40-g-PAA50)-b-PEO5]18 as the soft template, AgNO3 as a precursor, and tetrabutylammonium borohydride (TBAB) as the reducing agent. The overall size of the achieved Ag@Template NCs is controlled by the template structure at around 40 nm (Dh in DMF), and the size of the Ag grain can be easily regulated from ∼1 to ∼5 nm by adjusting the feeding ratio of AgNO3/acrylic acid (AA) units in the template from 1:10 to 1:1. Benefitting from the structural design of the template, all Ag@Template NCs prepared here exhibit excellent dispersibility and chemical stability in different aqueous environments (neutral, pH = 5.5, and 0.9% NaCl physiological saline solution), which play a crucial role in the long-term storage and potential application in a complex physiological environment. The antibacterial and cytotoxicity tests indicate that Ag@Template NCs display much better performance than Ag nanoparticles (Ag NPs), which have a comparable overall size of ∼25 nm. The inhibitory capability of Ag@Template NCs to bacteria strongly depends on the grain size. Specifically, the Ag@Template-1 NC assembled by the smallest grains (1.6 ± 0.3 nm) presents the best antibacterial activity. For E. coli (-), the MIC value is as low as 5 µg/mL (0.36 µg/mL of Ag), while for S. aureus (+), the value is around 10 µg/mL (0.72 µg/mL of Ag). The survival rate of L02 cells and lactate dehydrogenase assay together illustrate the low cytotoxicity possessed by the prepared Ag@Template NCs. Therefore, the proposed Ag@Template NC structure successfully resolves the high reactivity, instability, and fast oxidation issues of the ultrasmall Ag nanoparticles, and integrates high antibacterial efficiency and nontoxicity to biological cells into one platform, which implies its broad potential application in biomedicine.


Assuntos
Antibacterianos/efeitos adversos , Antibacterianos/química , Nanopartículas Metálicas/química , Prata/química , Antibacterianos/metabolismo , Boroidretos/química , Sobrevivência Celular/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana , Tamanho da Partícula , Polímeros/química , Compostos de Amônio Quaternário/química , Staphylococcus aureus/efeitos dos fármacos , Propriedades de Superfície , Nanomedicina Teranóstica
10.
Nutrients ; 13(7)2021 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-34371869

RESUMO

Hibiscus sabdariffa L. (H.s.) is a polyphenolic-rich plant commonly consumed either as a beverage or spice. The aim of the present study was to evaluate the in vitro digestibility of H.s. polyphenols using an in vitro model of digestion which simulates the human stomach and small intestine. The bioaccessible polyphenols released in the digested samples were analyzed by liquid chromatography coupled to photodiode array and mass spectrometry detection. H.s. anthocyanins (cyanidin-3-O-sambubioside and delphinidin-3-O-sambubioside) content drastically dropped during the digestion process from 2.91 ± 0.03 µg g-1 and 8.53 ± 0.08 µg g-1 (w/w) CG (Cyanidin-glucoside) in the raw extract, respectively, to 0.12 ± 0.01 µg g-1 0.12 ± 0.01 µg g-1 (w/w) CG at the end of duodenal digestion. Total polyphenols also have shown a decrease from 1192.65 ± 30.37 µg g-1 (w/w) in the raw extract to 282.24 ± 7.21 µg g-1 (w/w) by the end of gastric digestion, in contrast to their increase by the end of duodenal digestion 372.91 ± 3.97 µg g-1 (w/w). On the other hand, the decrease in certain compounds (e.g., caffeoylquinicandcoumaroylquinic acids) was observed during gastric digestion resulting in an increase of quinic acid in the duodenal aliquots, thus suggesting that this compound was derived from the degradation of the more complex hydroxycinnamic acids. H.s. extract also exhibited a bacteriostatic effect against Staphylococcus aureus ATCC 6538 (MIC of 2.5 mg mL-1) and a bactericidal effect against a food isolate of Listeria monocytogenes (MBC of 2.5 mg mL-1). The undigested polyphenols of H.s. in the upper gastrointestinal tract enters the colon, where they are metabolized by the gut microbiota. The present study results showed that resistance of H.s. polyphenols during gastrointestinal digestion might affect their uptake, resulting in a decrease in their digestibility.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Digestão , Hibiscus , Extratos Vegetais/farmacologia , Polifenóis/farmacologia , Antibacterianos/isolamento & purificação , Antibacterianos/metabolismo , Bactérias/crescimento & desenvolvimento , Disponibilidade Biológica , Cromatografia Líquida de Alta Pressão , Suco Gástrico/química , Hibiscus/química , Humanos , Secreções Intestinais/química , Listeria monocytogenes/efeitos dos fármacos , Listeria monocytogenes/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/metabolismo , Polifenóis/isolamento & purificação , Polifenóis/metabolismo , Espectrometria de Massas por Ionização por Electrospray , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Espectrometria de Massas em Tandem
11.
J Med Microbiol ; 70(7)2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34269673

RESUMO

Introduction. Staphylococcus aureus is a major cause of hospital infections worldwide. Awareness towards methicillin-resistant S. aureus (MRSA) infections is high but attention towards borderline oxacillin-resistant S. aureus (BORSA) is limited, possibly due to an underestimated clinical relevance, presumption of low incidence and diagnostic limitations.Gap statement. BORSA surveillance has not been routinely implemented, and thus consensus with regard to a definition and infection control measures is lacking.Aim. Our goals were to investigate the occurrence, molecular characteristics and clinical manifestations of BORSA infections in the hospital setting.Methodology. Following an increased incidence in 2016, BORSA cases in 2014/2016 (in our institution) were more specifically evaluated. Medical records were reviewed to investigate epidemiological links, clinical characteristics and outcomes. Resistance and virulence markers were assessed by whole genome sequencing (WGS). Conventional methods: amplified fragment length polymorphism (AFLP) ; multilocus sequence typing (MLST) and multiple locus variable-number tandem repeat analysis (MLVA) were compared with core genome MLST (cgMLST) and whole-genome single nucleotide polymorphism (wgSNP) analysis to confirm genetic clusters.Results. From 2009 to 2013, BORSA comprised 0.1 % of all clinical S. aureus strains. In 2016, the incidence was six-fold higher in comparison to the baseline. Whole-genome SNP and cgMLST confirmed two BORSA clusters among patients with dermatological conditions. Patients with BORSA presented with skin infections, and one case developed a severe invasive infection with a fatal outcome. Infection control measures successfully prevented further transmission in both clusters. WGS findings showed that BORSA strains carried multiple resistance and virulence genes with increased pathogenic potential.Conclusion. WGS and cgMLST effectively characterized and confirmed BORSA clusters among at-risk patients with clinical manifestations ranging from mild skin infections to life-threatening bacteraemia. Clinical awareness and active monitoring are therefore warranted for the timely implementation of infection control measures to prevent BORSA transmission in high-risk patients.


Assuntos
Antibacterianos/farmacologia , Infecção Hospitalar/microbiologia , Farmacorresistência Bacteriana , Oxacilina/farmacologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/genética , Staphylococcus aureus/isolamento & purificação , Infecção Hospitalar/transmissão , Genoma Bacteriano , Hospitais/estatística & dados numéricos , Humanos , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Polimorfismo de Nucleotídeo Único , Infecções Estafilocócicas/transmissão , Staphylococcus aureus/classificação , Staphylococcus aureus/efeitos dos fármacos , Sequenciamento Completo do Genoma
12.
Molecules ; 26(13)2021 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-34206777

RESUMO

Previous studies have revealed the numerous biological activities of the fruits of Illicium verum; however, the activities of its leaves and twigs have remained undiscovered. The study aimed to investigate the phytochemical components and antibacterial activity of the various extracts from the leaves and twigs of Illicium verum. The herbal extracts were prepared by supercritical CO2 extraction (SFE) and 95% ethanol extraction, followed by partition extraction based on solvent polarity. Analysis of antimicrobial activity was conducted through the usage of nine clinical antibiotic- resistant isolates, including Staphylococcus aureus, Pseudomonas aeruginosa and Acinetobacter baumannii. Among the tested samples, the SFE extracts exhibited broader and stronger antibacterial activities against the test strains, with a range of MIC between 0.1-4.0 mg/mL and MBC between 0.2-4.5 mg/mL. Observations made through scanning electron microscopy revealed potential mechanism of the antimicrobial activities involved disruption of membrane integrity of the test pathogens. Evaluation of the chemical composition by gas chromatography-mass spectrometry indicated the presence of anethole, anisyl aldehyde, anisyl acetone and anisyl alcohol within the SFE extracts, demonstrating significant correlations with the antibacterial activities observed. Therefore, the leaves and twigs of Illicium verum hold great potential in being developed as new natural antibacterial agents.


Assuntos
Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Illicium/química , Extratos Vegetais/análise , Extratos Vegetais/farmacologia , Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/ultraestrutura , Antibacterianos/análise , Anti-Infecciosos/análise , Membrana Celular/efeitos dos fármacos , Membrana Celular/ultraestrutura , Sobrevivência Celular/efeitos dos fármacos , Cromatografia Gasosa , Espectrometria de Massas , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Extratos Vegetais/química , Folhas de Planta/química , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/ultraestrutura , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/ultraestrutura
13.
BMC Infect Dis ; 21(1): 701, 2021 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-34294061

RESUMO

BACKGROUND: Atopic dermatitis (AD) is one of the most frequent chronic and inflammatory skin condition. AD is characterized by damaged epidermal barrier, xerosis and pruritus of eczematous skin lesions which tend to flare. The duration and frequency of exacerbation of AD symptoms markedly affects the quality of patient life. AD results from the interplay between host genetics, immunity, and environmental factors, however the detailed pathogenesis of this disease is still not entirely cleared. Furthermore, disturbances of the skin microbiota and skin functional impairment predispose to secondary skin infections. Staphylococcus aureus colonizes skin and mucous membranes of 20 to 80% of healthy individuals and of 90% of patients with AD in whom this bacterium is accounted as an important AD exacerbating factor. It is also proven, that S. aureus nasal carriage significantly increases the risk for self-transmission and endogenous infection. In the current study the presence of S. aureus either in nasal vestibule and on lesioned skin of 64 patients with AD enrolled in 10-year autovaccination program was determined. The genetic relatedness of 86 S. aureus isolated from patients nose and skin using Pulsed Field Gel Electrophoresis (PFGE) and antimicrobial susceptibility of all strains to methicillin, erythromycin, clindamycin, mupirocin, gentamicin, amikacin, tetracycline, chloramphenicol and cotrimoxazole was also evaluated. RESULTS: In total 23 PFGE genotypes and 24 unique patterns were distinguished. 34 patients were S. aureus nasal carriers. Simultaneous presence of S. aureus in nose and on affected skin was found in 16 carriers colonized by indistinguishable or potentially related S. aureus vs 2 carriers colonized with non-related S. aureus in nasal vestibule and on skin. 4 isolates were methicillin resistant (MRSA) among which 3 showed constitutive MLSB resistance phenotype and remaining one was resistant to tetracycline and chloramphenicol. In 4 isolates inducible MLSB resistance phenotype was found, one of them was additionally resistant to tetracycline. 7 S. aureus were mupirocin resistant among them 3 - isolated from one patient, were resistant simultaneously to tetracyclines and chloramphenicol. 7 strains demonstrated resistance to chloramphenicol and susceptibility to all tested antimicrobial agents. The susceptibility to gentamicin, amikacin and cotrimoxazole among all examined S. aureus was confirmed. CONCLUSION: The obtained results indicated non-clonal structure of S. aureus circulating in AD patients. PFGE results showed the clonal-structure of vast majority of S. aureus isolated from nose and skin from nasal carriers what may prove the autoinfection in these patients. All examined patients the moderate or strong severity of AD was reported. Susceptibility to most antibiotics among isolated strains was also observed.


Assuntos
Antibacterianos/farmacologia , Dermatite Atópica/microbiologia , Cavidade Nasal/microbiologia , Pele/microbiologia , Staphylococcus aureus/genética , Adulto , Dermatite Atópica/terapia , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Polônia , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/isolamento & purificação
14.
Int J Mol Sci ; 22(13)2021 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-34203313

RESUMO

The paper presents a synthesis of poly(l-lactide) with bacteriostatic properties. This polymer was obtained by ring-opening polymerization of the lactide initiated by selected low-toxic zinc complexes, Zn[(acac)(L)H2O], where L represents N-(pyridin-4-ylmethylene) tryptophan or N-(2-pyridin-4-ylethylidene) phenylalanine. These complexes were obtained by reaction of Zn[(acac)2 H2O] and Schiff bases, the products of the condensation of amino acids and 4-pyridinecarboxaldehyde. The composition, structure, and geometry of the synthesized complexes were determined by NMR and FTIR spectroscopy, elemental analysis, and molecular modeling. Both complexes showed the geometry of a distorted trigonal bipyramid. The antibacterial and antifungal activities of both complexes were found to be much stronger than those of the primary Schiff bases. The present study showed a higher efficiency of polymerization when initiated by the obtained zinc complexes than when initiated by the zinc(II) acetylacetonate complex. The synthesized polylactide showed antibacterial properties, especially the product obtained by polymerization initiated by a zinc(II) complex with a ligand based on l-phenylalanine. The polylactide showed a particularly strong antimicrobial effect against Pseudomonas aeruginosa, Staphylococcus aureus, and Aspergillus brasiliensis. At the same time, this polymer does not exhibit fibroblast cytotoxicity.


Assuntos
Poliésteres/química , Polímeros/química , Zinco/química , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Aspergillus/efeitos dos fármacos , Quelantes/química , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos
15.
Expert Opin Drug Metab Toxicol ; 17(9): 1039-1048, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34225556

RESUMO

Introduction: Usage of ceftriaxone-based therapy to treat Methicillin-Susceptible Staphylococcus aureus (MSSA) infections is a controversial issue, from in vitro to clinical studies.Area covered: We conducted a literature review using PubMed of articles with ceftriaxone pharmacokinetics parameters and built a probability of target attainment (PTA) based on PK values from stable conditions (non-critically-ill patients) with goals of fT>55%, fT>75%, and fT>100%. Ceftriaxone's minimal inhibitory concentration from 31 MSSA strains (0.25-64 mg/L) was used to build the cumulative fraction response (CFR). The isolates were clinically relevant from blood, bronchoalveolar lavage, and soft tissue biopsy.Expert opinion: The results from controversies about using ceftriaxone for MSSA infections have been commonly addressed in the literature. However, variables such as (i) pharmacokinetic profile, (ii) pharmacodynamic target, (iii) site of infection, and (iv) MIC distributions may influence divergences. From this pharmacokinetics-pharmacodynamics perspective, ceftriaxone may be a reasonable option for MSSA infections when the MIC50 and MIC90 were 4 mg/L and 8 mg/L. CFR analysis demonstrated that ceftriaxone 1 g q24 h could be used if bacteriostasis is the aim (fT>55%), while 1 g q12h should be used for bactericidal effects (fT>75% or fT>100%). These dosing regimens should be considered in other clinical trials.


Assuntos
Antibacterianos/administração & dosagem , Ceftriaxona/administração & dosagem , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/farmacocinética , Antibacterianos/farmacologia , Ceftriaxona/farmacocinética , Ceftriaxona/farmacologia , Esquema de Medicação , Farmacorresistência Bacteriana , Humanos , Meticilina/farmacologia , Testes de Sensibilidade Microbiana , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/isolamento & purificação
16.
Front Immunol ; 12: 639570, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34194425

RESUMO

Bacteriophages are able to affect the human immune system. Phage-specific antibodies are considered as major factors shaping phage pharmacokinetics and bioavailability. So far, general knowledge of phage antigenicity nevertheless remains extremely limited. Here we present comparative studies of immunogenicity in two therapeutic bacteriophages, A3R and 676Z, active against Staphylococcus aureus, routinely applied in patients at the Phage Therapy Unit, Poland. Comparison of the overall ability of whole phages to induce specific antibodies in a murine model revealed typical kinetics of IgM and IgG induction by these two phages. In further studies we identified the location of four phage proteins in the virions, with the focus on the external capsid head (Mcp) or tail sheath (TmpH) or an unidentified precise location (ORF059 and ORF096), and we confirmed their role as structural proteins of these viruses. Next, we compared the immune response elicited by these proteins after phage administration in mice. Similar to that in T4 phage, Mcp was the major element of the capsid that induced specific antibodies. Studies of protein-specific sera revealed that antibodies specific to ORF096 were able to neutralize antibacterial activity of the phages. In humans (population level), none of the studied proteins plays a particular role in the induction of specific antibodies; thus none potentially affects in a particular way the effectiveness of A3R and 676Z. Also in patients subjected to phage therapy, we did not observe increased specific immune responses to the investigated proteins.


Assuntos
Imunidade/imunologia , Mamíferos/imunologia , Fagos de Staphylococcus/imunologia , Staphylococcus aureus/efeitos dos fármacos , Animais , Antibacterianos/farmacologia , Anticorpos/imunologia , Formação de Anticorpos/imunologia , Capsídeo/imunologia , Proteínas do Capsídeo/imunologia , Humanos , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Cinética , Masculino , Mamíferos/microbiologia , Mamíferos/virologia , Camundongos , Camundongos Endogâmicos C57BL , Terapia por Fagos/métodos , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/imunologia , Infecções Estafilocócicas/virologia , Staphylococcus aureus/imunologia , Staphylococcus aureus/virologia , Vírion/imunologia
17.
Molecules ; 26(14)2021 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-34299454

RESUMO

In this study, a new broth macrodilution volatilization method for the simple and rapid determination of the antibacterial effect of volatile agents simultaneously in the liquid and vapor phase was designed with the aim to assess their therapeutic potential for the development of new inhalation preparations. The antibacterial activity of plant volatiles (ß-thujaplicin, thymohydroquinone, thymoquinone) was evaluated against bacteria associated with respiratory infections (Haemophilus influenzae, Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus pyogenes) and their cytotoxicity was determined using a modified thiazolyl blue tetrazolium bromide assay against normal lung fibroblasts. Thymohydroquinone and thymoquinone possessed the highest antibacterial activity against H. influenzae, with minimum inhibitory concentrations of 4 and 8 µg/mL in the liquid and vapor phases, respectively. Although all compounds exhibited cytotoxic effects on lung cells, therapeutic indices (TIs) suggested their potential use in the treatment of respiratory infections, which was especially evident for thymohydroquinone (TI > 34.13). The results demonstrate the applicability of the broth macrodilution volatilization assay, which combines the principles of broth microdilution volatilization and standard broth macrodilution methods. This assay enables rapid, simple, cost- and labor-effective screening of volatile compounds and overcomes the limitations of assays currently used for screening of antimicrobial activity in the vapor phase.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Óleos Voláteis/farmacologia , Administração por Inalação , Antibacterianos/análise , Bactérias/efeitos dos fármacos , Benzoquinonas/administração & dosagem , Benzoquinonas/farmacologia , Haemophilus influenzae/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Monoterpenos/administração & dosagem , Monoterpenos/farmacologia , Óleos Voláteis/química , Staphylococcus aureus/efeitos dos fármacos , Streptococcus pneumoniae/efeitos dos fármacos , Streptococcus pyogenes/efeitos dos fármacos , Timol/administração & dosagem , Timol/análogos & derivados , Timol/farmacologia , Tropolona/administração & dosagem , Tropolona/análogos & derivados , Tropolona/farmacologia , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/farmacologia , Volatilização
18.
J Enzyme Inhib Med Chem ; 36(1): 1509-1520, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34238110

RESUMO

In the present study, a series of azo derivatives (TR-1 to TR-9) have been synthesised via the diazo-coupling approach between substituted aromatic amines with phenol or naphthol derivatives. The compounds were evaluated for their therapeutic applications against alpha-glucosidase (anti-diabetic) and pathogenic bacterial strains E. coli (gram-negative), S. aureus (gram-positive), S. aureus (gram-positive) drug-resistant strain, P. aeruginosa (gram-negative), P. aeruginosa (gram-negative) drug-resistant strain and P. vulgaris (gram-negative). The IC50 (µg/mL) of TR-1 was found to be most effective (15.70 ± 1.3 µg/mL) compared to the reference drug acarbose (21.59 ± 1.5 µg/mL), hence, it was further selected for the kinetic studies in order to illustrate the mechanism of inhibition. The enzyme inhibitory kinetics and mode of binding for the most active inhibitor (TR-1) was performed which showed that the compound is a non-competitive inhibitor and effectively inhibits the target enzyme by binding to its binuclear active site reversibly.


Assuntos
Antibacterianos/farmacologia , Compostos Azo/farmacologia , Inibidores Enzimáticos/farmacologia , Hipoglicemiantes/farmacologia , Simulação de Acoplamento Molecular , alfa-Glucosidases/metabolismo , Antibacterianos/síntese química , Antibacterianos/química , Compostos Azo/síntese química , Compostos Azo/química , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Escherichia coli/efeitos dos fármacos , Hipoglicemiantes/síntese química , Hipoglicemiantes/química , Cinética , Testes de Sensibilidade Microbiana , Estrutura Molecular , Pseudomonas aeruginosa/efeitos dos fármacos , Saccharomyces cerevisiae/enzimologia , Staphylococcus aureus/efeitos dos fármacos
19.
J Photochem Photobiol B ; 221: 112249, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34237541

RESUMO

Increasing interests in photodynamic treatment (PDT) for food preservation require a holistic method to evaluate and compare different photosensitizer (PS)-light treatments. In this report, the absorbed photons were used as the basis to assess the antimicrobial photodynamic efficacy of two PSs, chlorophyllin sodium magnesium salt (Chl-Mg) and chlorophyllin sodium copper salt (Chl-Cu), under blue and white light against two typical foodborne pathogens, Gram-negative Escherichia coli, and Gram-positive Staphylococcus aureus. The results showed that the phototoxicity of a PS was predominantly decided by the absorbed photons rather than the characteristics of light sources. Photosensitized Chl-Mg exhibited superior antimicrobial activity as compared to that of ChlCu. The applied treatments were found to be more effective against S. aureus than E. coli. Bacterial inactivation kinetics as a function of the number of absorbed photons could be described by Weibull model with R2 from 0.947-0.962, and kinetics constants D in the range of 0.202 × 1017 photons/cm2-2.409 × 1018 photons/cm2. The kinetics models may find promising applications in the design, assessment, and optimization of PDT processes.


Assuntos
Escherichia coli/efeitos dos fármacos , Luz , Fármacos Fotossensibilizantes/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Clorofilídeos/química , Cobre/química , Escherichia coli/efeitos da radiação , Microbiologia de Alimentos , Magnésio/química , Oxigênio Singlete/química , Oxigênio Singlete/metabolismo , Sódio/química , Staphylococcus aureus/efeitos da radiação
20.
Methods Mol Biol ; 2341: 45-54, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34264460

RESUMO

This chapter describes the use of antibiotic kill curves to examine the tolerance of Staphylococcus aureus to any antibiotic of interest. This is done by treating cultures with a super-minimum inhibitory concentration (MIC) of antibiotic and measuring viability over time by colony-forming units (CFUs). Kill curves provide a unique insight into S. aureus antibiotic tolerance and death patterns that may not be clear from other experiments, such as traditional MIC or Kirby-Bauer assays.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Staphylococcus aureus/crescimento & desenvolvimento , Contagem de Colônia Microbiana , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos
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