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1.
Int J Nanomedicine ; 16: 1849-1867, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33707943

RESUMEN

Background: With the development of bacterial resistance, the range of effective antibiotics is increasingly becoming more limited. The effective use of nanoscale antimicrobial peptides (AP) in therapeutic and diagnostic methods is a strategy for new antibiotics. Methods: Combining both AP and cadmium selenide (CdSe) into a composite material may result in a reagent with novel properties, such as enhanced antibacterial activity, fluorescence and favorable stability in aqueous solution. Results: AP-loaded CdSe NPs (AP-CdSe NPs) showed strong antibacterial activity against multidrug-resistant (MDR) Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) in vitro and in vivo. Colony-forming unit (CFU) and minimum inhibitory concentration (MIC) assays showed that AP-CdSe NPs have highly effective antibacterial activity. The quantitative analysis of apoptosis by flow cytometry analysis further confirmed that MDR E. coli and S. aureus treated with AP-CdSe NPs had death rates of 98.76% and 99.13%, respectively. Also, AP-CdSe NPs was found to inhibit bacterial activity in an in vivo bacteremia model in mice infected with S. aureus. In addition, the antibacterial mechanism of AP-CdSe NPs was determined by RNA sequencing analysis. Gene ontology (GO) analysis and Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis revealed the molecular mechanism of the antibacterial effect of AP-CdSe NPs. Importantly, histopathology analysis, and hematological toxicity analysis indicated that AP-CdSe NPs had few side effects. Conclusion: These results demonstrate that AP loaded on CdSe NPs had a higher water solubility, bioavailability and antibacterial effect compared with raw AP. This study reports findings that are helpful for the design and development of antibacterial treatment strategies based on AP.


Asunto(s)
Antibacterianos/farmacología , Compuestos de Cadmio/química , Luminiscencia , Nanopartículas/química , Proteínas Citotóxicas Formadoras de Poros/farmacología , Puntos Cuánticos/química , Compuestos de Selenio/química , Animales , Apoptosis/efectos de los fármacos , Apoptosis/genética , Bacteriemia/microbiología , Recuento de Colonia Microbiana , Modelos Animales de Enfermedad , Endocitosis/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Escherichia coli/genética , Escherichia coli/ultraestructura , Femenino , Perfilación de la Expresión Génica , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Ontología de Genes , Ratones Desnudos , Pruebas de Sensibilidad Microbiana , Microscopía Fluorescente , Nanopartículas/ultraestructura , Proteínas Citotóxicas Formadoras de Poros/efectos adversos , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/ultraestructura
2.
Molecules ; 26(5)2021 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-33652788

RESUMEN

Molybdates are biocidal materials that can be useful in coating surfaces that are susceptible to contamination and the spread of microorganisms. The aim of this work was to investigate the effects of copper doping of hydrated cobalt molybdate, synthesized by the co-precipitation method, on its antibacterial activity and to elucidate the structural and morphological changes caused by the dopant in the material. The synthesized materials were characterized by PXRD, Fourier Transformed Infrared (FTIR), thermogravimetric analysis/differential scanning calorimetry (TG/DSC), and SEM-Energy Dispersive Spectroscopy (SEM-EDS). The antibacterial response of the materials was verified using the Minimum Inhibitory Concentration (MIC) employing the broth microdilution method. The size of the CoMoO4·1.03H2O microparticles gradually increased as the percentage of copper increased, decreasing the energy that is needed to promote the transition from the hydrated to the beta phase and changing the color of material. CoMoO4·1.03H2O obtained better bactericidal performance against the tested strains of Staphylococcus aureus (gram-positive) than Escherichia coli (gram-negative). However, an interesting point was that the use of copper as a doping agent for hydrated cobalt molybdate caused an increase of MIC value in the presence of E. coli and S. aureus strains. The study demonstrates the need for caution in the use of copper as a doping material in biocidal matrices, such as cobalt molybdate.


Asunto(s)
Antiinfecciosos/química , Cobalto/química , Cobre/química , Molibdeno/química , Antiinfecciosos/farmacología , Infecciones Bacterianas/tratamiento farmacológico , Complejos de Coordinación/química , Escherichia coli/efectos de los fármacos , Humanos , Nanopartículas del Metal/química , Pruebas de Sensibilidad Microbiana , Tamaño de la Partícula , Staphylococcus aureus/efectos de los fármacos
3.
Int J Food Microbiol ; 344: 109116, 2021 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-33676332

RESUMEN

Staphylococcus aureus is among the most common zoonotic pathogens originating from animals consumed as food, especially raw chicken meat (RCM). As far as we know, this might be the first report that explores the efficacy of metal oxide nanoparticles (MONPs), such as zinc peroxide nanoparticles (ZnO2-NPs), zinc oxide nanoparticles (ZnO-NPs), and titanium dioxide nanoparticles (TiO2-NPs) against multidrug resistant (MDR) and/or pandrug resistant (PDR) S. aureus strains with a strong biofilm-producing ability isolated from RCM and giblets. The overall prevalence of coagulase-positive staphylococci was 21%, with a contamination level range between 102 and 104 CFU/g. The incidence of virulence genes See (21/36), pvl (16/36), clfA (15/36), sec (12/36), tst (12/36), and sea (11/36) among S. aureus strains were relatively higher those of seb, sed, fnbA, and fnbB. For antimicrobial resistance gene distribution, most strains harbored the blaZ gene (25/36), aacA-aphD gene (24/36), mecA gene (22/36), vanA gene (20/36), and apmA gene (20/36) confirmed the prevalence of MDR among S. aureus of RCM products. However, cfr (11/36), spc (9/36), and aadE (7/36) showed a relatively lower existence. The data of antibiogram resistance profiles was noticeably heterogeneous (25 patterns) with 32 MDR and four PDR S. aureus strains. All tested strains had a very high MAR index value (>0.2) except the P11 pattern (GEN, MXF, PMB), which showed a MAR index of 0.19. Among the strong biofilm-producing ability (BPA), 14 (70%) strains were isolated from wet markets, while only six strong BPA strains were isolated from supermarkets. The mean values of BPA ranged from 2.613 ± 0.04 to 11.013 ± 0.05. Clearly, ZnO2-NPs show significant inhibitory activity against S. aureus strains compared with those produced by the action of ZnO-NPs and TiO2-NPs. The results of anti-inflammatory activity suggest ZnO2-NPs as a lead compound for designing an alternative antimicrobial agent against drug-resistant and strong biofilm-producing S. aureus isolates from retail RCM and giblets.


Asunto(s)
Antibacterianos/farmacología , Contaminación de Alimentos/prevención & control , Staphylococcus aureus/crecimiento & desarrollo , Titanio/farmacología , Óxido de Zinc/farmacología , Animales , Biopelículas/efectos de los fármacos , Biopelículas/crecimiento & desarrollo , Pollos/microbiología , Farmacorresistencia Bacteriana Múltiple/genética , Contaminación de Alimentos/análisis , Microbiología de Alimentos , Carne/microbiología , Nanopartículas del Metal , Pruebas de Sensibilidad Microbiana , Infecciones Estafilocócicas/epidemiología , Infecciones Estafilocócicas/prevención & control , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/aislamiento & purificación , Virulencia/genética
4.
Molecules ; 26(4)2021 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-33669712

RESUMEN

Hydroxyapatite (HA) is the main inorganic mineral that constitutes bone matrix and represents the most used biomaterial for bone regeneration. Over the years, it has been demonstrated that HA exhibits good biocompatibility, osteoconductivity, and osteoinductivity both in vitro and in vivo, and can be prepared by synthetic and natural sources via easy fabrication strategies. However, its low antibacterial property and its fragile nature restricts its usage for bone graft applications. In this study we functionalized a MgHA scaffold with gold nanorods (AuNRs) and evaluated its antibacterial effect against S. aureus and E. coli in both suspension and adhesion and its cytotoxicity over time (1 to 24 days). Results show that the AuNRs nano-functionalization improves the antibacterial activity with 100% bacterial reduction after 24 h. The toxicity study, however, indicates a 4.38-fold cell number decrease at 24 days. Although further optimization on nano-functionalization process are needed for cytotoxicity, these data indicated that Au-NRs nano-functionalization is a very promising method for improving the antibacterial properties of HA.


Asunto(s)
Antiinfecciosos/farmacología , Durapatita/farmacología , Oro/farmacología , Magnesio/farmacología , Nanotubos/química , Muerte Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Humanos , Pruebas de Sensibilidad Microbiana , Nanotubos/ultraestructura , Espectroscopía de Fotoelectrones , Staphylococcus aureus/efectos de los fármacos , Andamios del Tejido/química
5.
Molecules ; 26(4)2021 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-33670315

RESUMEN

Arabian flora is a rich source of bioactive compounds. In this study, we investigated three aromatic plant species with the aim of finding valuable sources of antimicrobial agents against common pathogenic microorganisms. We focused especially on microorganisms, which cause outbreaks of infectious disease during mass gatherings and pilgrimages season in Saudi Arabia. The essential oils of three aromatic plant species were hydrodistilled from flowering aerial parts of Lavandula pubescens Decne. and Pulicaria incisa subsp. candolleana E.Gamal-Eldin, and from leaves, stems, ripe and unripe fruits of Juniperus procera Hochst. Ex Endl. They were subsequently analyzed by gas chromatography-mass spectrometry (GC-MS). The main constituents of L. pubescens were found to be carvacrol (55.7%), methyl carvacrol (13.4%), and ß-bisabolene (9.1%). P. incisa subsp. Candolleana essential oil was rich in linalool (33.0%), chrysanthenone (10.3%), eugenol (8.9%), and cis-chrysanthenol (8.0%); the major components of J. procera essential oil were α-pinene (31.3-62.5%) and δ-3-carene (7.3-30.3%). These essential oils were tested against thirteen American Type Culture Collection (ATCC) strains of Gram-positive and Gram-negative bacteria using the agar diffusion assay. The only effective essential oil was that of L. pubescens and the most sensitive strains were Acinetobacter baumannii, Salmonella typhimurium, Shigella sonnei, Enterococcus faecalis and Staphylococcus epidermidis. Carvacrol, the major constituent of L. pubescens, was tested on these strains and was compared with vancomycin, amikacin, and ciprofloxacin. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) assays of L. pubescens essential oil and carvacrol revealed that Gram-negative strains were more susceptible than the Gram-positive ones.


Asunto(s)
Juniperus/química , Lavandula/química , Aceites Volátiles/química , Aceites Vegetales/química , Pulicaria/química , Antibacterianos/química , Antibacterianos/farmacología , Cimenos/química , Cimenos/farmacología , Enterococcus faecalis/efectos de los fármacos , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Humanos , Pruebas de Sensibilidad Microbiana , Aceites Volátiles/farmacología , Componentes Aéreos de las Plantas/química , Hojas de la Planta/química , Aceites Vegetales/farmacología , Arabia Saudita , Staphylococcus aureus/efectos de los fármacos
6.
Carbohydr Polym ; 260: 117772, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33712130

RESUMEN

Nanoparticle-polymer composites are important functional materials but structural control of their assembly is challenging. Owing to its crystalline internal structure and tunable nanoscale morphology, cellulose is promising polymer scaffold for templating such composite materials. Here, we show bottom-up synthesis of reducing end thiol-modified cellulose chains by iterative bi-enzymatic ß-1,4-glycosylation of 1-thio-ß-d-glucose (10 mM), to a degree of polymerization of ∼8 and in a yield of ∼41% on the donor substrate (α-d-glucose 1-phosphate, 100 mM). Synthetic cellulose oligomers self-assemble into highly ordered crystalline (cellulose allomorph II) material showing long (micrometers) and thin nanosheet-like morphologies, with thickness of 5-7 nm. Silver nanoparticles were attached selectively and well dispersed on the surface of the thiol-modified cellulose, in excellent yield (≥ 95%) and high loading efficiency (∼2.2 g silver/g thiol-cellulose). Examined against Escherichia coli and Staphylococcus aureus, surface-patterned nanoparticles show excellent biocidal activity. Bottom-up approach by chemical design to a functional cellulose nanocomposite is presented. Synthetic thiol-containing nanocellulose can expand the scope of top-down produced cellulose materials.


Asunto(s)
Antibacterianos/química , Celulosa/química , Nanopartículas del Metal/química , Nanocompuestos/química , Compuestos de Sulfhidrilo/química , Antibacterianos/farmacología , Pruebas Antimicrobianas de Difusión por Disco , Escherichia coli/efectos de los fármacos , Nanocompuestos/toxicidad , Plata/química , Staphylococcus aureus/efectos de los fármacos
7.
Carbohydr Polym ; 260: 117777, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33712133

RESUMEN

The combination of alginate, hyaluronic acid and multivalent ions have been reported to form alginate-hyaluronic acid ionic-crosslinking hydrogels for biomedical applications. However, injectable alginate-hyaluronic acid ionic-crosslinking hydrogels with satisfactory shear-thinning property have rarely been reported. In this study, we successfully developed an ionic-crosslinked alginate-hyaluronic acid hydrogel by simple assembly of alginate-hyaluronic acid mixture and Fe3+ complex. This hydrogel could fully recover within seconds after damaged, while displayed shear thinning behavior and good injectability which were contributed by the reversible and dynamic metal-ligand interactions formed via ferric ions and carboxyl groups of the polymers. Moreover, the local degradation of this hydrogel giving the hydrogel sustained ferric ions release property, of which led to potential long-term antibacterial activities against multiple types of bacteria including gram-negative Escherichia coli and gram-positive Staphylococcus aureus, as well as representative oral pathogenic bacteria Streptococcus mutans and Porphyromonas gingivalis.


Asunto(s)
Alginatos/química , Antiinfecciosos/química , Compuestos Férricos/química , Ácido Hialurónico/química , Hidrogeles/química , Animales , Antiinfecciosos/farmacología , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Línea Celular , Supervivencia Celular/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Femenino , Compuestos Férricos/metabolismo , Humanos , Hidrogeles/farmacología , Ratones , Ratones Endogámicos BALB C , Porphyromonas/efectos de los fármacos , Reología , Piel/efectos de los fármacos , Piel/patología , Staphylococcus aureus/efectos de los fármacos , Streptococcus mutans/efectos de los fármacos
8.
Life Sci ; 273: 119306, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33662434

RESUMEN

AIMS: The present study aims to target the quorum sensing (QS) accessory gene regulator A (AgrA) of Staphylococcus aureus to curtail bacterial virulence through drug repurposing approach. MAIN METHODS: In silico screening of chemical ligands that bind specifically to the S. aureus C-LytTR domain of AgrA (AgrAC) was carried out. AgrA inhibition and downregulation of virulence genes linked to QS system of S. aureus were determined. Efficacy, dermal toxicity and drug tolerance induction were tested in Balb/C mice dermonecrosis model. KEY FINDINGS: Bumetanide bound to the conserved amino acid Tyr-229 of AgrA and showed 70% AgrA inhibition at 0.1 µM. Highly significant reduction in the expression of representative virulence genes such as alpha-hemolysin (~5 log2-fold), phenol-soluble modulins (~4 log2-fold) and panton-valentine leukocidin (~3 log2-fold) was noted in vitro. In vivo studies signified bumetanide to be highly effective in controlling the ulcer development and promoted wound healing. Also, the tested substance did not have dermal toxicity and no tolerance induction as well. SIGNIFICANCE: Targeting the QS regulators could be a possible alternative approach to curtail virulence in S. aureus. In addition, if the QS inhibitors are repurposed it could accelerate the drug development process and reduce the cost. The identified drug bumetanide inhibited AgrA and the results were in comparable to that of a known virulence inhibitor, diflunisal. The newly reported results of bumetanide in this study are expected to mark the drug's visibility for antibiotic adjunctive therapy and topical drug formulations for skin infections research.


Asunto(s)
Proteínas Bacterianas/antagonistas & inhibidores , Bumetanida/farmacología , Reposicionamiento de Medicamentos , Inhibidores del Simportador de Cloruro Sódico y Cloruro Potásico/farmacología , Infecciones Estafilocócicas/tratamiento farmacológico , Staphylococcus aureus/efectos de los fármacos , Transactivadores/antagonistas & inhibidores , Virulencia/efectos de los fármacos , Animales , Femenino , Ratones , Ratones Endogámicos BALB C , Percepción de Quorum , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/crecimiento & desarrollo
9.
Molecules ; 26(4)2021 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-33672630

RESUMEN

Despite advances achieved over the last decade, infections caused by multi-drug-resistant bacterial strains are increasingly becoming important societal issues that need to be addressed. New approaches have already been developed in order to overcome this problem. Photodynamic antimicrobial chemotherapy (PACT) could provide an alternative to fight infectious bacteria. Many studies have highlighted the value of cationic photosensitizers in order to improve this approach. This study reports the synthesis and the characterization of cationic porphyrins derived from methylimidazolium and phenylimidazolium porphyrins, along with a comparison of their photophysical properties with the well-known N-methylpyridyl (pyridinium) porphyrin family. PACT tests conducted with the tetracationic porphyrins of these three families showed that these new photosensitizers may offer a good alternative to the classical pyridinium porphyrins, especially against S.aureus and E.coli. In addition, they pave the way to new cationic photosensitizers by the means of derivatization through amide bond formation.


Asunto(s)
Antibacterianos/farmacología , Imidazoles/farmacología , Fotoquimioterapia , Fármacos Fotosensibilizantes/farmacología , Porfirinas/farmacología , Piridinas/farmacología , Antibacterianos/síntesis química , Antibacterianos/química , Relación Dosis-Respuesta a Droga , Escherichia coli/efectos de los fármacos , Imidazoles/síntesis química , Imidazoles/química , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Fármacos Fotosensibilizantes/síntesis química , Fármacos Fotosensibilizantes/química , Porfirinas/síntesis química , Porfirinas/química , Pseudomonas aeruginosa/efectos de los fármacos , Piridinas/síntesis química , Piridinas/química , Staphylococcus aureus/efectos de los fármacos
10.
Molecules ; 26(4)2021 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-33672753

RESUMEN

The cell wall of Mycobacterium tuberculosis (Mtb) has a unique structural organisation, comprising a high lipid content mixed with polysaccharides. This makes cell wall a formidable barrier impermeable to hydrophilic agents. In addition, during host infection, Mtb resides in macrophages within avascular necrotic granulomas and cavities, which shield the bacterium from the action of most antibiotics. To overcome these protective barriers, a new class of anti-TB agents exhibiting lipophilic character have been recommended by various reports in literature. Herein, a series of lipophilic heterocyclic quinolone compounds was synthesised and evaluated in vitro against pMSp12::GFP strain of Mtb, two protozoan parasites (Plasmodium falciparum and Trypanosoma brucei brucei) and against ESKAPE pathogens. The resultant compounds exhibited varied anti-Mtb activity with MIC90 values in the range of 0.24-31 µM. Cross-screening against P. falciparum and T.b. brucei, identified several compounds with antiprotozoal activities in the range of 0.4-20 µM. Compounds were generally inactive against ESKAPE pathogens, with only compounds 8c, 8g and 13 exhibiting moderate to poor activity against S. aureus and A. baumannii.


Asunto(s)
Antibacterianos/farmacología , Antiprotozoarios/farmacología , Quinolonas/farmacología , Acinetobacter baumannii/efectos de los fármacos , Antibacterianos/síntesis química , Antibacterianos/química , Antiprotozoarios/síntesis química , Antiprotozoarios/química , Relación Dosis-Respuesta a Droga , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Pruebas de Sensibilidad Parasitaria , Plasmodium falciparum/efectos de los fármacos , Quinolonas/síntesis química , Quinolonas/química , Staphylococcus aureus/efectos de los fármacos , Trypanosoma brucei brucei/efectos de los fármacos
11.
Carbohydr Polym ; 260: 117803, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33712151

RESUMEN

Biofilm-related infections and contamination of biomaterials are major problems in the clinic. These contaminations are frequently caused by Staphylococcus aureus and are a pressing issue for implantable devices, catheters, contact lenses, prostheses, and wound dressings. Strategies to decrease contamination and biofilm related infections are vital for the success of implantable biomaterials. In this context, hyaluronic acid (HA), a naturally derived carbohydrate polymer, known to be biocompatible, degradable, and immunomodulatory, has shown some antimicrobial activity effects. Due to its poor structural stability, crosslinking strategies, and the incorporation of reinforcing fibres in HA gels is required to produce tailored gels for varying applications. Whilst carbon-based reinforcing materials, such as carbon nanofibers (CNF), present some intrinsic antimicrobial activity related to their high surface area, herein, a crosslinking strategy to enhance the mechanical properties and regulate the rate of degradation of HA is presented. We utilise bis-(ß-isocyanatoethyl) disulphide (BIED) as the crosslinker with the gel reinforced using 0.25 wt% CNF. The effects of CNF and BIED on the structural, mechanical, thermal, and swelling behaviour are examined. These new HA derivatives exhibit excellent mechanical properties and are capable of withstanding physiological stresses in vivo. Antimicrobial activity of the HA derivatives were tested against Staphylococcus aureus and the results reveal antibacterial effect. These carbohydrate based materials have potential application on surfaces within clinical settings where staphylococcal contamination is currently an issue.


Asunto(s)
Antibacterianos/química , Ácido Hialurónico/química , Animales , Antibacterianos/farmacología , Biopelículas/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Reactivos de Enlaces Cruzados/química , Geles/química , Ácido Hialurónico/farmacología , Ratones , Células 3T3 NIH , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/fisiología , Temperatura , Resistencia a la Tracción
12.
Carbohydr Polym ; 260: 117806, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33712152

RESUMEN

Chitin-encapsulated cadmium sulfide quantum dots (CdS@CTN QDs) were successfully synthesized from chitin and Cd(NO3)2 precursor using the colloidal chemistry method, toward the development of biocompatible and biodegradable QDs for biomedical applications. CdS@CTN QDs exhibited the nanocrystalline cubic CdS encapsulated by α-chitin. The average particle size of CdS@CTN QDs was estimated using empirical Henglein model to be 3.9 nm, while their crystallite size was predicted using Scherrer equation to be 4.3 nm, slightly larger compared to 3-mercaptopropionic acid-capped CdS QDs (3.2 and 3.6 nm, respectively). The mechanism of formation was interpreted based on the spectroscopic data and X-ray crystal structures of CdS@CTN QDs fabricated at different pH values and mass ratios of chitin to Cd(NO3)2 precursor. As an important step to explore potential biomolecular and biological applications of CdS@CTN QDs, their antibacterial activities were tested against four different bacterial strains; i.e. Escherichia coli, Bacillus subtillus, Staphylococcus aureus and Pseudomonas aeruginosa.


Asunto(s)
Antibacterianos/química , Materiales Biocompatibles/química , Quitina/química , Puntos Cuánticos/química , Antibacterianos/farmacología , Materiales Biocompatibles/farmacología , Compuestos de Cadmio/química , Escherichia coli/efectos de los fármacos , Tamaño de la Partícula , Pseudomonas aeruginosa/efectos de los fármacos , Staphylococcus aureus/efectos de los fármacos , Sulfuros/química
13.
Carbohydr Polym ; 260: 117835, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33712172

RESUMEN

Bacterial breeding is the main cause of food perishability, which is harmful to human health. Silver nanoparticles (AgNPs) are one of the most widely used antimicrobial agents, but they are easy to release and cause cumulative toxicity. In this work, with corn stalk as green reductant and GO as template, a simple electrostatic self-assembled sandwich-like chitosan (CS) wrapped rGO@AgNPs nanocomposite film (CS/rGO@AgNPs) was synthesized to achieve stabilizing and controlled-release of AgNPs. The results showed that the the CS/rGO@AgNPs film continued releasing AgNPs for up to 14 days, and the final release amount of silver nanoparticles was only about 1.9 %. More importantly, the nanocomposite film showed durable antibacterial effect and good antibacterial activity against E. coli and S. aureus, and they showed no toxicity to cells. Hence, the nanocomposite film has potential application as an effective and safe packaging material to prolong the shelf life of food products.


Asunto(s)
Antibacterianos/química , Quitosano/química , Grafito/química , Nanopartículas del Metal/química , Nanocompuestos/química , Antibacterianos/farmacología , Línea Celular , Supervivencia Celular/efectos de los fármacos , Materiales Biocompatibles Revestidos/química , Materiales Biocompatibles Revestidos/farmacología , Escherichia coli/efectos de los fármacos , Humanos , Nanocompuestos/toxicidad , Plata/química , Solubilidad , Staphylococcus aureus/efectos de los fármacos , Resistencia a la Tracción
14.
Arch Insect Biochem Physiol ; 106(3): e21771, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33644898

RESUMEN

Antimicrobial proteins (AMPs) are small, cationic proteins that exhibit activity against bacteria, viruses, parasites, fungi as well as boost host-specific innate immune responses. Insects produce these AMPs in the fat body and hemocytes, and release them into the hemolymph upon microbial infection. Hemolymph was collected from the bacterially immunized fifth instar larvae of tasar silkworm, Antheraea mylitta, and an AMP was purified by organic solvent extraction followed by size exclusion and reverse-phase high-pressure liquid chromatography. The purity of AMP was confirmed by thin-layer chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. The molecular mass was determined by matrix-assisted laser desorption ionization-time of flight mass spectrometry as 14 kDa, and hence designated as AmAMP14. Peptide mass fingerprinting of trypsin-digested AmAMP14 followed by de novo sequencing of one peptide fragment by tandem mass spectrometry analysis revealed the amino acid sequences as CTSPKQCLPPCK. No homology was found in the database search and indicates it as a novel AMP. The minimum inhibitory concentration of the purified AmAMP14 was determined against Escherichia coli, Staphylococcus aureus, and Candida albicans as 30, 60, and 30 µg/ml, respectively. Electron microscopic examination of the AmAMP14-treated cells revealed membrane damage and release of cytoplasmic contents. All these results suggest the production of a novel 14 kDa AMP in the hemolymph of A. mylitta to provide defense against microbial infection.


Asunto(s)
Péptidos Catiónicos Antimicrobianos , Hemolinfa/metabolismo , Proteínas de Insectos/aislamiento & purificación , Mariposas Nocturnas/metabolismo , Animales , Antibacterianos/química , Antibacterianos/aislamiento & purificación , Antibacterianos/farmacología , Péptidos Catiónicos Antimicrobianos/química , Péptidos Catiónicos Antimicrobianos/aislamiento & purificación , Péptidos Catiónicos Antimicrobianos/farmacología , Candida albicans/efectos de los fármacos , Cromatografía en Gel/métodos , Cromatografía Líquida de Alta Presión/métodos , Escherichia coli/efectos de los fármacos , Proteínas de Insectos/química , Proteínas de Insectos/metabolismo , Proteínas de Insectos/farmacología , Larva/metabolismo , Extracción Líquido-Líquido/métodos , Pruebas de Sensibilidad Microbiana , Staphylococcus aureus/efectos de los fármacos
15.
Int J Mol Sci ; 22(5)2021 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-33673498

RESUMEN

For bioactive milk peptides to be relevant to infant health, they must be released by gastrointestinal proteolysis and resist further proteolysis until they reach their site of activity. The intestinal tract is the likeliest site for most bioactivities, but it is currently unknown whether bioactive milk peptides are present therein. The purpose of the present study was to identify antimicrobial and bifidogenic peptides in the infant intestinal tract. Milk peptides were extracted from infant intestinal samples, and the activities of the bulk peptide extracts were determined by measuring growth of Escherichia coli, Staphylococcus aureus, and Bifidobacterium longum spp. infantis after incubation with serial dilutions. The peptide profiles of active and inactive samples were determined by peptidomics analysis and compared to identify candidate peptides for bioactivity testing. We extracted peptides from 29 intestinal samples collected from 16 infants. Five samples had antimicrobial activity against S. aureus and six samples had bifidogenic activity for B. infantis. We narrowed down a list of 6645 milk peptides to 11 candidate peptides for synthesis, of which 6 fully inhibited E. coli and S. aureus growth at concentrations of 2500 and 3000 µg/mL. This study provides evidence for the potential bioactivity of milk peptides in the infant intestinal tract.


Asunto(s)
Bifidobacterium longum subspecies infantis/efectos de los fármacos , Bifidobacterium longum subspecies infantis/crecimiento & desarrollo , Escherichia coli/efectos de los fármacos , Intestinos/microbiología , Péptidos/farmacología , Staphylococcus aureus/efectos de los fármacos , Antibacterianos/farmacología , Humanos , Lactante , Intestinos/química , Leche Humana/química
16.
Carbohydr Polym ; 259: 117739, 2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-33673999

RESUMEN

To fabricate antibacterial activity and simultaneous strengthened and toughened carboxylated nitrile butadiene rubber (XNBR) composites, starch was oxidized by H2O2 to achieve oxidized starch (OST) with different carboxyl content, meanwhile, ZnO were utilized to promote the in-situ interfacial reaction for improving compatibility of starch and XNBR. The formation of ionic cross-link networks and "Zinc-carboxylate polymers" in the XNBR/OST/ZnO composites were confirmed by FT-IR, XRD, XPS, SEM-EDS and TEM. Interestingly, because of the carboxyl groups of OSTs which provided a low pH surroundings to inhibit the growth of bacteria, XNBR/OST/ZnO composites achieved a significant antibacterial activity. Noteworthy, the sulfur-free XNBR composites achieved 3.04 and 1.99 times increase for tensile strength and elongation at break compared with neat XNBR. The mechanism of simultaneous strengthened and toughened for composites had been proposed. These new sustainable, green and facile fabricated XNBR/OST/ZnO could be utilized as the medical protective appliance to against the bacteria.


Asunto(s)
Butadienos/química , Nitrilos/química , Goma/química , Almidón/química , Antibacterianos/química , Antibacterianos/farmacología , Nanocompuestos/química , Oxidación-Reducción , Pseudomonas fluorescens/efectos de los fármacos , Goma/farmacología , Staphylococcus aureus/efectos de los fármacos , Temperatura , Resistencia a la Tracción , Zea mays/metabolismo , Óxido de Zinc/química
17.
Int J Mol Sci ; 22(4)2021 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-33672995

RESUMEN

Multidrug-resistant (MDR) bacteria constitute a global health issue. Over the past ten years, interest in nanoparticles, particularly metallic ones, has grown as potential antibacterial candidates. However, as there is no consensus about the procedure to characterize the metallic nanoparticles (MNPs; i.e., metallic aggregates) and evaluate their antibacterial activity, it is impossible to conclude about their real effectiveness as a new antibacterial agent. To give part of the answer to this question, 12 nm gold and silver nanoparticles have been prepared by a chemical approach. After their characterization by transmission electronic microscopy (TEM), Dynamic Light Scattering (DLS), and UltraViolet-visible (UV-vis) spectroscopy, their surface accessibility was tested through the catalytic reduction of the 4-nitrophenol, and their stability in bacterial culture medium was studied. Finally, the antibacterial activities of 12 nm gold and silver nanoparticles facing Staphylococcus aureus and Escherichia coli have been evaluated using the broth microdilution method. The results show that gold nanoparticles have a weak antibacterial activity (i.e., slight inhibition of bacterial growth) against the two bacteria tested. In contrast, silver nanoparticles have no activity on S. aureus but demonstrate a high antibacterial activity against Escherichia coli, with a minimum inhibitory concentration of 128 µmol/L. This high antibacterial activity is also maintained against two MDR-E. coli strains.


Asunto(s)
Antibacterianos/toxicidad , Escherichia coli/efectos de los fármacos , Oro/química , Nanopartículas del Metal/toxicidad , Plata/química , Staphylococcus aureus/efectos de los fármacos , Antibacterianos/química , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Dispersión Dinámica de Luz , Escherichia coli/crecimiento & desarrollo , Nanopartículas del Metal/química , Nanopartículas del Metal/ultraestructura , Pruebas de Sensibilidad Microbiana/métodos , Microscopía Electrónica de Transmisión , Espectrofotometría , Staphylococcus aureus/crecimiento & desarrollo
18.
Rev Esp Quimioter ; 34(2): 81-92, 2021 Apr.
Artículo en Español | MEDLINE | ID: mdl-33749214

RESUMEN

From a microbiological point of view, both empirical and targeted antimicrobial treatment in respiratory infection is based on the sensitivity profile of isolated microorganisms and the possible resistance mechanisms that they may present. The latter may vary in different geographic areas according to prescription profiles and vaccination programs. Beta-lactam antibiotics, fluoroquinolones, and macrolides are the most commonly used antimicrobials during the exacerbations of chronic obstructive pulmonary disease and community-acquired pneumonia. In their prescription, different aspects such as intrinsic activity, bactericidal effect or their ability to prevent the development of resistance must be taken into account. The latter is related to the PK/PD parameters, the mutant prevention concentration and the so-called selection window. More recently, the potential ecological impact has grown in importance, not only on the intestinal microbiota, but also on the respiratory one. Maintaining the state of eubiosis requires the use of antimicrobials with a low profile of action on anaerobic bacteria. With their use, the resilience of the bacterial populations belonging to the microbiota, the state of resistance of colonization and the collateral damage related to the emergence of resistance to the antimicrobials in pathogens causing the infections and in the bacterial populations integrating the microbiota.


Asunto(s)
Antibacterianos/farmacología , Farmacorresistencia Bacteriana , Enfermedad Pulmonar Obstructiva Crónica/tratamiento farmacológico , Infecciones del Sistema Respiratorio/tratamiento farmacológico , Administración Oral , Antibacterianos/administración & dosificación , Chlamydophila pneumoniae/efectos de los fármacos , Infecciones Comunitarias Adquiridas/tratamiento farmacológico , Infecciones Comunitarias Adquiridas/microbiología , Progresión de la Enfermedad , Microbioma Gastrointestinal/efectos de los fármacos , Haemophilus influenzae/efectos de los fármacos , Humanos , Pruebas de Sensibilidad Microbiana , Moraxella catarrhalis/efectos de los fármacos , Mycoplasma pneumoniae/efectos de los fármacos , Pseudomonas aeruginosa/efectos de los fármacos , Enfermedad Pulmonar Obstructiva Crónica/microbiología , Infecciones del Sistema Respiratorio/microbiología , Staphylococcus aureus/efectos de los fármacos , Streptococcus pneumoniae/efectos de los fármacos
19.
Int J Mol Sci ; 22(4)2021 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-33669209

RESUMEN

Nisin Z, an amphipathic peptide, with a significant antibacterial activity against Gram-positive bacteria and low toxicity in humans, has been studied for food preservation applications. Thus far, very little research has been done to explore its potential in biomedicine. Here, we report the modification of sodium alginate (SA) and gelatin (GN) blended microfibers, produced via the wet-spinning technique, with Nisin Z, with the purpose of eradicating Staphylococcus aureus-induced infections. Wet-spun SAGN microfibers were successfully produced at a 70/30% v/v of SA (2 wt%)/GN (1 wt%) polymer ratio by extrusion within a calcium chloride (CaCl2) coagulation bath. Modifications to the biodegradable fibers' chemical stability and structure were then introduced via crosslinking with CaCl2 and glutaraldehyde (SAGNCL). Regardless of the chemical modification employed, all microfibers were labelled as homogeneous both in size (≈246.79 µm) and shape (cylindrical and defect-free). SA-free microfibers, with an increased surface area for peptide immobilization, originated from the action of phosphate buffer saline solution on SAGN fibers, were also produced (GNCL). Their durability in physiological conditions (simulated body fluid) was, however, compromised very early in the experiment (day 1 and 3, with and without Nisin Z, respectively). Only the crosslinked SAGNCL fibers remained intact for the 28 day-testing period. Their thermal resilience in comparison with the unmodified and SA-free fibers was also demonstrated. Nisin Z was functionalized onto the unmodified and chemically altered fibers at an average concentration of 178 µg/mL. Nisin Z did not impact on the fiber's morphology nor on their chemical/thermal stability. However, the peptide improved the SA fibers (control) structural integrity, guaranteeing its stability for longer, in physiological conditions. Its main effect was detected on the time-kill kinetics of the bacteria S. aureus. SAGNCL and GNCL loaded with Nisin Z were capable of progressively eliminating the bacteria, reaching an inhibition superior to 99% after 24 h of culture. The peptide-modified SA and SAGN were not as effective, losing their antimicrobial action after 6 h of incubation. Bacteria elimination was consistent with the release kinetics of Nisin Z from the fibers. In general, data revealed the increased potential and durable effect of Nisin Z (significantly superior to its free, unloaded form) against S. aureus-induced infections, while loaded onto prospective biomedical wet-spun scaffolds.


Asunto(s)
Alginatos/química , Antibacterianos/química , Antibacterianos/farmacología , Reactivos de Enlaces Cruzados/química , Gelatina/química , Nisina/análogos & derivados , Staphylococcus aureus/efectos de los fármacos , Materiales Biocompatibles/química , Plásticos Biodegradables/química , Biopolímeros/química , Cloruro de Calcio/química , Sistemas de Liberación de Medicamentos/métodos , Liberación de Fármacos , Glutaral/química , Cinética , Pruebas de Sensibilidad Microbiana , Nisina/química , Nisina/farmacología , Porosidad , Solubilidad , Infecciones Estafilocócicas/tratamiento farmacológico , Infecciones Estafilocócicas/microbiología , Agua/química
20.
ACS Appl Mater Interfaces ; 13(11): 12912-12927, 2021 Mar 24.
Artículo en Inglés | MEDLINE | ID: mdl-33715350

RESUMEN

The current pandemic caused by SARS-CoV-2 has seen a widespread use of personal protective equipment, especially face masks. This has created the need to develop better and reusable protective masks with built-in antimicrobial, self-cleaning, and aerosol filtration properties to prevent the transmission of air-borne pathogens such as the coronaviruses. Herein, molybdenum disulfide (MoS2) nanosheets are used to prepare modified polycotton fabrics having excellent antibacterial activity and photothermal properties. Upon sunlight irradiation, the nanosheet-modified fabrics rapidly increased the surface temperature to ∼77 °C, making them ideal for sunlight-mediated self-disinfection. Complete self-disinfection of the nanosheet-modified fabric was achieved within 3 min of irradiation, making the fabrics favorably reusable upon self-disinfection. The nanosheet-modified fabrics maintained the antibacterial efficiency even after 60 washing cycles. Furthermore, the particle filtration efficiency of three-layered surgical masks was found to be significantly improved through incorporation of the MoS2-modified fabric as an additional layer of protective clothing, without compromising the breathability of the masks. The repurposed surgical masks could filter out around 97% of 200 nm particles and 96% of 100 nm particles, thus making them potentially useful for preventing the spread of coronaviruses (120 nm) by trapping them along with antibacterial protection against other airborne pathogens.


Asunto(s)
Antiinfecciosos/química , Disulfuros/química , Molibdeno/química , Nanoestructuras/química , Equipo de Protección Personal , Reciclaje , Antiinfecciosos/farmacología , /virología , Escherichia coli/efectos de los fármacos , Escherichia coli/metabolismo , Glutatión/química , Humanos , Nanoestructuras/toxicidad , Oxidación-Reducción , Tamaño de la Partícula , Especies Reactivas de Oxígeno/metabolismo , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/metabolismo , Luz Solar , Temperatura
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