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1.
An. pediatr. (2003. Ed. impr.) ; 97(2): 95-102, ago, 2022. tab
Artigo em Inglês, Espanhol | IBECS | ID: ibc-207559

RESUMO

Introducción: Staphylococcus aureus (S. aureus) es un germen frecuente en las infecciones bacterianas infantiles. Últimamente la tasa de S. aureus resistente a meticilina (SAMR) está aumentando.Objetivos: Principal: conocer la tasa de cultivos positivos a SAMR en los servicios de urgencias pediátricos españoles. Secundarios: analizar factores de riesgo de aislamiento de SAMR (procedencia del paciente, antecedentes de hospitalización o cirugía en los 90 días previos, de antibioterapia en los 60 días previos, presencia de comorbilidad, dispositivos invasivos, aislamiento SAMR previo) y la morbilidad de estas infecciones.Metodología: Estudio retrospectivo multicéntrico (1/07/2017-30/06/2018) con revisión de historias de pacientes con aislamiento de S. aureus en muestras de cualquier origen obtenidas en 8 servicios de urgencias pediátricos del Grupo de Trabajo de Enfermedades Infecciosas de la Sociedad Española de Urgencias de Pediatría.Resultados: Durante dicho periodo se aisló S. aureus en 403 pacientes (edad media 75,8±59,2 meses; 54,8% hombres): 28,8% infecciones relacionadas con el hospital y 71,2% con la comunidad. Tasa global de SAMR: 16,6% (IC95%: 13-20,2%); 18,1% en infecciones relacionadas con el hospital y 16,2% en infecciones relacionadas con la comunidad (p>0,05). Las tasas más altas de SAMR se obtuvieron en abscesos cutáneos (29,3%; IC95%: 21,8-36,8%), pacientes no nacidos en España (52%; IC95%: 32-72%) o con una infección previa por SAMR (90%; IC95% 71,4-100%). Ingresaron 167 pacientes (41%), presentaron complicaciones 12 (3%) y secuelas 4 (1%). No hubo fallecimientos. (AU)


Introduction: Staphylococcusaureus (S. aureus) is a common germ present in bacterial infections in children. Lately, the rate of methicillin-resistant S. aureus (MRSA) is increasing.Objectives: The main aim of this study is to know the rate of positive cultures to MRSA in Spanish pediatric emergency departments. The secondary aims are to analyze the risk factors for MRSA isolation (patient origin, history of hospitalization or surgery in the previous 90 days, antibiotherapy in the previous 60 days, presence of comorbidity, invasive devices, prior MRSA isolation) and to analyze the morbidity of these infections.Methodology: Retrospective multicenter study (07/01/2017–06/30/2018) with review of patient histories with isolation of S. aureus in samples of any origin obtained in 8 pediatric emergency departments of the Infectious Diseases Working Group of the Spanish Society of Pediatric Emergencies.Results: During this period, S. aureus was detected in 403 patients (average age 75.8±59.2 months; 54.8% male): 28.8% hospital-related infections and 71.2% community-related infections. Overall, MRSA rate was 16.6% (95% CI: 13-20.2%); 18.1% in hospital-related infections and 16.2% in community-related infections (P>.05). The highest rates of MRSA were obtained in skin abscesses (29.3%, 95% CI: 21.8-36.8%), patients not born in Spain (52%; 95% CI: 32-72%) or patients with a previous MRSA infection (90%; 95% CI: 71.4-100%).167 (41%) patients were admitted, 12 (3%) had complications and 4 (1%) suffered sequels. There were no deaths. (AU)


Assuntos
Humanos , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus aureus/isolamento & purificação , Serviços de Saúde da Criança , Estudos Retrospectivos , Espanha
2.
Mar Drugs ; 20(3)2022 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-35323468

RESUMO

Volatile compounds from the marine cyanolichen Lichina pygmaea, collected from the Moroccan Atlantic coast, were extracted by hydrodistillation and their putative chemical composition was investigated by gas chromatography coupled to mass spectrometry (GC/MS). Based on the obtained results, Lichina pygmaea volatile compounds (LPVCs) were mainly dominated by sesquiterpenes compounds, where γ-himachalene, ß-himachalene, (2E,4E)-2,4 decadienal and α-himachalene were assumed to be the most abundant constituents, with percentage of 37.51%, 11.71%, 8.59% and 7.62%, respectively. LPVCs depicted significant antimicrobial activity against all tested strains (Staphylococcus aureus CCMM B3, Pseudomonas aeruginosa DSM 50090, Escherichia coli ATCC 8739 and Candida albicans CCMM-L4) with minimum inhibitory concentration (MIC) values within the range of 1.69-13.5 mg/mL. Moreover, this LPVC showed interesting scavenging effects on the 2,2-diphenyl-1-picrylhydrazyl radical with an IC50 of 0.21 mg/mL. LPVCs could be an approving resource with moderate antimicrobial potential and interesting antioxidant activity for cosmetics and pharmaceutical applications.


Assuntos
Anti-Infecciosos , Antioxidantes , Ascomicetos/química , Sesquiterpenos , Compostos Orgânicos Voláteis , Anti-Infecciosos/química , Anti-Infecciosos/isolamento & purificação , Anti-Infecciosos/farmacologia , Antioxidantes/química , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Compostos de Bifenilo/química , Candida albicans/efeitos dos fármacos , Candida albicans/crescimento & desenvolvimento , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Picratos/química , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/crescimento & desenvolvimento , Sesquiterpenos/análise , Sesquiterpenos/isolamento & purificação , Sesquiterpenos/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/isolamento & purificação , Compostos Orgânicos Voláteis/farmacologia
3.
Microbiol Spectr ; 10(1): e0231321, 2022 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-35196815

RESUMO

Persisters are transiently nongrowing and antibiotic-tolerant phenotypic variants identified in major human pathogens, including intracellular Staphylococcus aureus. Due to their capacity to regrow once the environmental stress is relieved and to promote resistance, persisters possibly contribute to therapeutic failures. While persistence and its related quiescence have been mostly studied under starvation, little is known within host cell environments. Here, we examined how the level of reactive oxygen species (ROS) in different host cells affects dormancy depth of intracellular S. aureus. Using single-cell approaches, we found that host ROS induce variable dormant states in S. aureus persisters, displaying heterogeneous and increased lag times for resuscitation in liquid medium. Dormant persisters displayed decreased translation and energy metabolism, but remained infectious, exiting from dormancy and resuming growth when reinoculated in low-oxidative-stress cells. In high-oxidative-stress cells, ROS-induced ATP depletion was associated with the formation of visible dark foci similar to those induced by the protein aggregation inducer CCCP (carbonyl cyanide m-chlorophenylhydrazone) and with the recruitment of the DnaK-ClpB chaperone system involved in the clearance of protein aggregates. ATP depletion led to higher fractions of dormant persisters than ROS, due to a counterbalancing effect of ROS-induced translational repression, suggesting a pivotal role of translation in the dormant phenotype. Consistently, protein synthesis inhibition limited dormancy to levels similar to those observed in low-oxidative-stress cells. This study supports the hypothesis that intracellular S. aureus persisters can reach heterogeneous dormancy depths and highlights the link between ROS, ATP depletion, dark focus formation, and subsequent dormancy state. IMPORTANCE By their capacity to survive to antibiotic pressure and to regrow and give rise to a susceptible population once this pressure is relieved, intracellular persisters of S. aureus may contribute to explain therapeutic failures and recurrent infections. Here, we show that the level of dormancy and the subsequent capacity to resuscitate from this resting state are dependent on the level of oxidative stress in the host cells where bacteria survive. This observation nourishes the debate as whether the most appropriate strategy to cope with S. aureus intracellular infections would consist of trying to push persisters to a deep dormancy state from which wakening is improbable or, on the contrary, to prevent ROS-induced dormancy and force bacteria to maintain regular metabolism in order to restore their responsiveness to antibiotics. Importantly also, our data highlight the interest in single-cell analyses with conventional enumeration of CFU to quantify persisters and study host-pathogen interactions.


Assuntos
Estresse Oxidativo , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus aureus/metabolismo , Trifosfato de Adenosina/metabolismo , Antibacterianos/farmacologia , Metabolismo Energético , Humanos , Viabilidade Microbiana , Fenótipo , Espécies Reativas de Oxigênio/metabolismo , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/genética
4.
Int J Mol Sci ; 23(3)2022 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-35163108

RESUMO

The biodiversity of microorganisms is maintained by intricate nets of interactions between competing species. Impaired functionality of human microbiomes correlates with their reduced biodiversity originating from aseptic environmental conditions and antibiotic use. Microbiomes of wild animals are free of these selective pressures. Microbiota provides a protecting shield from invasion by pathogens in the wild, outcompeting their growth in specific ecological niches. We applied ultrahigh-throughput microfluidic technologies for functional profiling of microbiomes of wild animals, including the skin beetle, Siberian lynx, common raccoon dog, and East Siberian brown bear. Single-cell screening of the most efficient killers of the common human pathogen Staphylococcus aureus resulted in repeated isolation of Bacillus pumilus strains. While isolated strains had different phenotypes, all of them displayed a similar set of biosynthetic gene clusters (BGCs) encoding antibiotic amicoumacin, siderophore bacillibactin, and putative analogs of antimicrobials including bacilysin, surfactin, desferrioxamine, and class IId cyclical bacteriocin. Amicoumacin A (Ami) was identified as a major antibacterial metabolite of these strains mediating their antagonistic activity. Genome mining indicates that Ami BGCs with this architecture subdivide into three distinct families, characteristic of the B. pumilus, B. subtilis, and Paenibacillus species. While Ami itself displays mediocre activity against the majority of Gram-negative bacteria, isolated B. pumilus strains efficiently inhibit the growth of both Gram-positive S. aureus and Gram-negative E. coli in coculture. We believe that the expanded antagonistic activity spectrum of Ami-producing B. pumilus can be attributed to the metabolomic profile predetermined by their biosynthetic fingerprint. Ultrahigh-throughput isolation of natural probiotic strains from wild animal microbiomes, as well as their metabolic reprogramming, opens up a new avenue for pathogen control and microbiome remodeling in the food industry, agriculture, and healthcare.


Assuntos
Animais Selvagens/microbiologia , Antibacterianos/administração & dosagem , Bacillus pumilus/química , Escherichia coli/crescimento & desenvolvimento , Microbiota , Probióticos/administração & dosagem , Staphylococcus aureus/crescimento & desenvolvimento , Animais , Antibacterianos/isolamento & purificação , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Escherichia coli/efeitos dos fármacos , Genoma Bacteriano , Metaboloma , Família Multigênica , Probióticos/isolamento & purificação , Staphylococcus aureus/efeitos dos fármacos
5.
Int J Mol Sci ; 23(3)2022 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-35163814

RESUMO

Combining multiple drugs or biologically active substances for wound healing could not only resist the formation of multidrug resistant pathogens, but also achieve better therapeutic effects. Herein, the hydrophobic fluoroquinolone antibiotic ciprofloxacin (CIP) and the hydrophilic broad-spectrum antibiotic tetracycline hydrochloride (TH) were introduced into the coaxial polycaprolactone/gelatin (PCL/GEL) nanofiber mat with CIP loaded into the PCL (core layer) and TH loaded into the GEL (shell layer), developing antibacterial wound dressing with the co-delivering of the two antibiotics (PCL-CIP/GEL-TH). The nanostructure, physical properties, drug release, antibacterial property, and in vitro cytotoxicity were investigated accordingly. The results revealed that the CIP shows a long-lasting release of five days, reaching the releasing rate of 80.71%, while the cumulative drug release of TH reached 83.51% with a rapid release behavior of 12 h. The in vitro antibacterial activity demonstrated that the coaxial nanofiber mesh possesses strong antibacterial activity against E. coli and S. aureus. In addition, the coaxial mats showed superior biocompatibility toward human skin fibroblast cells (hSFCs). This study indicates that the developed PCL-CIP/GEL-TH nanofiber membranes hold enormous potential as wound dressing materials.


Assuntos
Ciprofloxacina/administração & dosagem , Escherichia coli/crescimento & desenvolvimento , Pele/citologia , Staphylococcus aureus/crescimento & desenvolvimento , Tetraciclina/administração & dosagem , Cicatrização , Animais , Bandagens , Linhagem Celular , Ciprofloxacina/química , Ciprofloxacina/farmacologia , Modelos Animais de Doenças , Composição de Medicamentos , Sinergismo Farmacológico , Escherichia coli/efeitos dos fármacos , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Gelatina/química , Humanos , Viabilidade Microbiana , Nanofibras , Poliésteres/química , Pele/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Tetraciclina/química , Tetraciclina/farmacologia
6.
Int J Mol Sci ; 23(3)2022 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-35163819

RESUMO

While blue LED (b-LED) light is increasingly being studied for its cytotoxic activity towards bacteria in therapy of skin-related infections, its effects on eukaryotic cells plasticity are less well characterized. Moreover, since different protocols are often used, comparing the effect of b-LED towards both microorganisms and epithelial surfaces may be difficult. The aim of this study was to analyze, in the same experimental setting, both the bactericidal activity and the effects on human keratinocytes. Exposure to b-LED induced an intense cytocidal activity against Gram-positive (i.e, Staphylococcus aureus) and Gram-negative (i.e., Pseudomonas aeruginosa) bacteria associated with catheter-related infections. Treatment with b-LED of a human keratinocyte cell line induced a transient cell cycle arrest. At the molecular level, exposure to b-LED induced a transient downregulation of Cyclin D1 and an upregulation of p21, but not signs of apoptosis. Interestingly, a transient induction of phosphor-histone γ-H2Ax, which is associated with genotoxic damages, was observed. At the same time, keratinocytes underwent a transient epithelial to mesenchymal transition (EMT)-like phenotype, characterized by E-cadherin downregulation and SNAIL/SLUG induction. As a functional readout of EMT induction, a scratch assay was performed. Surprisingly, b-LED treatment provoked a delay in the scratch closure. In conclusion, we demonstrated that b-LED microbicidal activity is associated with complex responses in keratinocytes that certainly deserve further analysis.


Assuntos
Pontos de Checagem do Ciclo Celular/efeitos da radiação , Queratinócitos/citologia , Luz/efeitos adversos , Pseudomonas aeruginosa/crescimento & desenvolvimento , Staphylococcus aureus/crescimento & desenvolvimento , Antígenos CD/metabolismo , Caderinas/metabolismo , Proliferação de Células , Ciclina D1/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Síndrome de Down , Transição Epitelial-Mesenquimal/efeitos da radiação , Regulação da Expressão Gênica/efeitos dos fármacos , Células HaCaT , Humanos , Queratinócitos/metabolismo , Queratinócitos/efeitos da radiação , Viabilidade Microbiana/efeitos da radiação , Pseudomonas aeruginosa/efeitos da radiação , Fatores de Transcrição da Família Snail/metabolismo , Staphylococcus aureus/efeitos da radiação
7.
Molecules ; 27(4)2022 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-35208951

RESUMO

A 24 kDa leucine-rich protein from ion exchange fractions of Solanum trilobatum, which has anti-bacterial activity against both the Gram-negative Vibrio cholerae and Gram-positive Staphylococcus aureus bacteria has been purified. In this study, mass spectrometry analysis identified the leucine richness and found a luminal binding protein (LBP). Circular dichroism suggests that the protein was predominantly composed of α- helical contents of its secondary structure. Scanning electron microscopy visualized the characteristics and morphological and structural changes in LBP-treated bacterium. Further in vitro studies confirmed that mannose-, trehalose- and raffinose-treated LBP completely inhibited the hemagglutination ability towards rat red blood cells. Altogether, these studies suggest that LBP could bind to sugar moieties which are abundantly distributed on bacterial surface which are essential for maintaining the structural integrity of bacteria. Considering that Solanum triolbatum is a well-known medicinal and edible plant, in order to shed light on its ancient usage in this work, an efficient anti-microbial protein was isolated, characterized and its in vitro functional study against human pathogenic bacteria was evaluated.


Assuntos
Antibacterianos , Folhas de Planta/química , Proteínas de Plantas , Solanum/química , Staphylococcus aureus/crescimento & desenvolvimento , Vibrio cholerae/crescimento & desenvolvimento , Antibacterianos/química , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Proteínas de Plantas/química , Proteínas de Plantas/isolamento & purificação , Proteínas de Plantas/farmacologia
8.
Int J Mol Sci ; 23(3)2022 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-35163197

RESUMO

Problems connected with biofilm-related infections and antibiotic resistance necessitate the investigation and development of novel treatment strategies. Given their unique characteristics, one of the most promising alternatives to conventional antibiotics are bacteriophages. In the in vitro and in vivo larva model study, we demonstrate that phages vB_SauM-A, vB_SauM-C, and vB_SauM-D are effective antibiofilm agents. The exposure of biofilm to phages vB_SauM-A and vB_SauM-D led to 2-3 log reductions in the colony-forming unit number in most of the multidrug-resistant S. aureus strains. It was found that phage application reduced the formed biofilms independently of the used titer. Moreover, the study demonstrated that bacteriophages are more efficient in biofilm biomass removal and reduction in staphylococci count when compared to the antibiotics used. The scanning electron microscopy analysis results are in line with colony forming unit (CFU) counting but not entirely consistent with crystal violet (CV) staining. Additionally, phages vB_SauM-A, vB_SauM-C, and vB_SauM-D can significantly increase the survival rate and extend the survival time of Galleria mellonella larvae.


Assuntos
Antibacterianos/farmacologia , Infecções Estafilocócicas/terapia , Staphylococcus aureus/efeitos dos fármacos , Bacteriólise/efeitos dos fármacos , Bacteriólise/genética , Bacteriófagos/genética , Bacteriófagos/patogenicidade , Biofilmes/efeitos dos fármacos , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Resistência a Múltiplos Medicamentos/genética , Genoma Viral/genética , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Terapia por Fagos/métodos , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/crescimento & desenvolvimento
9.
Molecules ; 27(4)2022 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-35209213

RESUMO

The design of multifunctional microcarriers has attracted significant attention because they combine various functions within a single system. In this study, we developed a set of multilayered hydrogel microcarriers, which were first loaded with chemotherapeutic curcumin (CUR), then, using the layer-by-layer (LbL) technique, coated through a polyelectrolyte shell consisting of chitosan (CHIT) or poly(allylamine hydrochloride) (PAH). As an outer layer with antimicrobial function, newly synthesised alkylene quaternary ammonium salt functionalised polyelectrolytes (A-QAS-PEs) were applied. For this purpose, poly(acrylic acid) (PAA) was decorated with different hydrophobic side chains (n-hexane and n-dodecane side entities) and different degrees of substitution (m) of quaternary ammonium groups (abbreviated as PAA-C(O)O-(CH2)n-N+(CH3)3(m); n = 6, 12; m = 8-14%). The grafting approach of PAA with the alkylene quaternary ammonium salt moiety was performed under mild reaction conditions using Steglich esterification followed by quaternisation. The structure of antimicrobial decorated PAA was confirmed by 1H NMR and FTIR, and the mean diameter of all multifunctional microparticles was characterised by SEM. The viscoelastic properties of the functional layers were studied using quartz crystal microbalance with a dissipation (QCM-D). The release of CUR from the microcarriers was described using a hybrid model, i.e., a combination of first-order kinetics and the Korsmeyer-Peppas model. The antimicrobial activity of functionalised PAA and multilayered CUR-loaded hydrogel microcarriers with quaternary ammonium function was assessed against Staphylococcus aureus and Serratia marcescens by the agar diffusion assay method. Only a limited inhibition zone of PAA was observed, but in the case of both antimicrobial decorated PAA and the corresponding multilayered nanocarriers, the inhibitory activity increase was achieved against both strains of bacteria.


Assuntos
Antibacterianos , Curcumina , Portadores de Fármacos , Hidrogéis , Serratia marcescens/crescimento & desenvolvimento , Staphylococcus aureus/crescimento & desenvolvimento , Antibacterianos/química , Antibacterianos/farmacocinética , Antibacterianos/farmacologia , Curcumina/química , Curcumina/farmacocinética , Curcumina/farmacologia , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Portadores de Fármacos/farmacologia , Hidrogéis/química , Hidrogéis/farmacocinética , Hidrogéis/farmacologia
10.
Carbohydr Polym ; 282: 119112, 2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-35123747

RESUMO

In this study, a biodegradable photodynamic antibacterial film (Car-Cur) was prepared using casting method with κ-Carrageenan (κ-Car) as film-forming substrate and curcumin-ß-cyclodextrin (Cur-ß-CD) complex as photosensitizer. The comprehensive performance of this Car-Cur film was investigated. The obtained results showed that the concentration of Cur-ß-CD was an important factor determining the properties of film including tensile strength (TS) elongation at break (EB), water vapor permeability (WVP), water content (WC) and thermal stability. When the concentration of Cur-ß-CD is 1%, the film demonstrated the maximum TS and EB, increased thermal stability, with desirable WVP and WC. Furthermore, this film also showed good photodynamic antibacterial potential against Staphylococcus aureus and Escherichia coli upon irradiation of blue LED light. Moreover, the film can be degraded in the soil in one week. In conclusion, our results suggested Car-Cur photodynamic film could be developed as biodegradable antimicrobial packaging material for food preservation.


Assuntos
Antibacterianos , Carragenina , Curcumina , Escherichia coli/efeitos dos fármacos , Fármacos Fotossensibilizantes , Staphylococcus aureus/efeitos dos fármacos , beta-Ciclodextrinas , Antibacterianos/administração & dosagem , Antibacterianos/química , Antibacterianos/efeitos da radiação , Carragenina/administração & dosagem , Carragenina/química , Carragenina/efeitos da radiação , Curcumina/administração & dosagem , Curcumina/química , Curcumina/efeitos da radiação , Escherichia coli/crescimento & desenvolvimento , Embalagem de Alimentos , Temperatura Alta , Luz , Fármacos Fotossensibilizantes/administração & dosagem , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/efeitos da radiação , Staphylococcus aureus/crescimento & desenvolvimento , Vapor , Resistência à Tração , beta-Ciclodextrinas/administração & dosagem , beta-Ciclodextrinas/química , beta-Ciclodextrinas/efeitos da radiação
11.
Carbohydr Polym ; 282: 119127, 2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-35123751

RESUMO

Chitosan, cellulose nanocrystals, and halloysite nanotubes in the presence of calcium cations were used to fabricate a three-dimensional nanocomposite scaffold. The FTIR and XRD analyses revealed that formation of the network and incorporation of halloysite nanotubes into it were successful. FESEM images showed that the addition of higher amounts of halloysite nanotubes into the scaffold's matrix leads to more and smaller pores. The addition of halloysite nanotubes enhanced the thermal stability, mechanical characteristics, water uptake, and degradation rate of the nanocomposite scaffold. The nanocomposite scaffold represented good biomineralization, great cell proliferation, and acceptable cell attachment. Furthermore, the capability of the nanocomposite scaffold for curcumin delivery was approved through cell proliferation, cumulative release, and antibacterial studies. Cell proliferation of the nanocomposite with 10 wt% curcumin-loaded halloysite nanotubes reached around 175% after 72 h. Considering the results, the prepared nanocomposite scaffold holds great potential for being used in bone tissue engineering applications.


Assuntos
Antibacterianos/química , Antioxidantes/química , Celulose/química , Quitosana/química , Argila/química , Curcumina/química , Nanopartículas/química , Nanotubos/química , Tecidos Suporte , Animais , Adesão Celular , Proliferação de Células , Escherichia coli/crescimento & desenvolvimento , Camundongos , Células NIH 3T3 , Nanocompostos/química , Staphylococcus aureus/crescimento & desenvolvimento
12.
Carbohydr Polym ; 282: 119130, 2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-35123752

RESUMO

Development of versatile medical dressing with good immediate and long-lasting antibacterial, hygroscopic and moisturizing abilities is of great significance for management of chronic wounds. Cotton gauze (CG) can protect wounds and promote scabbing, but can cause wound dehydration and loss of biologically active substances, thereby greatly delays wound healing. Herein, a bi-functional CG dressing (CPCG) was developed by chemically grafting polyhexamethylene guanidine (PHMG) and physically adsorbing chitosan (CS) onto the CG surface. Due to the powerful microbicidal activity of PHMG, CPCG exhibited excellent immediate and long-lasting antibacterial activity against gram-positive and gram-negative bacteria. Moreover, the abundant hydroxyl and amino groups in CS endowed CPCG with good biocompatibility, moisture absorption, moisturizing and cell scratch healing performances. Importantly, CPCG can be easily fabricated into a bandage to conveniently manage infected full-skin wounds. Together, this study suggests that CPCG is a versatile wound dressing, having enormous application potential for management chronic wounds.


Assuntos
Antibacterianos , Bandagens , Quitosana , Fibra de Algodão , Guanidinas , Animais , Movimento Celular , Células Cultivadas , Eritrócitos , Escherichia coli/crescimento & desenvolvimento , Feminino , Hemólise , Humanos , Camundongos Endogâmicos BALB C , Staphylococcus aureus/crescimento & desenvolvimento , Cicatrização , Infecção dos Ferimentos/prevenção & controle
13.
Carbohydr Polym ; 282: 119131, 2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-35123763

RESUMO

A multifunctional bilayer membrane with electrospinning chitosan (CS) and active ZnO nanoparticles was designed. The outer-layer was constructed with ZnO-encapsulated poly(ε-caprolactone) (PCL) ultrafine fibers in a randomly-orientated structure, which could impart the bilayer membrane with great antibacterial activity. The inner-layer was composed with CS fibers with aligned core-shell structure, which could provide anti-inflammatory and effective cell contact guide function. The structure, morphology and crystallization behavior of the bilayer membrane was investigated by FTIR, TEM, SEM and XRD. Importantly, the bi-layered CS/PCL electrospun membrane loading 1.2 wt% ZnO nanoparticles exhibited an enhanced tensile strength and an obvious inhibitory zone against E. coli and S. aureus, and also presented a non-cytotoxic behavior to fibroblasts. Moreover, the as-prepared bi-layered membrane enabled the maintenance of high bioavailability of ZnO nanoparticles and synchronization with the aligned structural feature of CS fibers, which alleviated inflammation, stimulated cellular migration and re-epithelialization in vivo.


Assuntos
Antibacterianos , Anti-Inflamatórios , Quitosana , Membranas Artificiais , Poliésteres , Óxido de Zinco , Animais , Movimento Celular , Proliferação de Células , Células Cultivadas , Escherichia coli/crescimento & desenvolvimento , Fibroblastos , Humanos , Masculino , Ratos , Staphylococcus aureus/crescimento & desenvolvimento , Cicatrização
14.
Can J Vet Res ; 86(1): 59-64, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34975224

RESUMO

Septic arthritis is considered a medical emergency. Disease following bacterial colonization can lead to significant morbidity and mortality and requires costly treatment. Antimicrobial properties of regenerative therapies, including mesenchymal stromal cells and platelet products, have been researched extensively in human medicine. Although fewer studies have been conducted in veterinary species, they have shown promising results. The purpose of this study was to evaluate bacterial suppression by equine platelet lysate (EPL) and adipose-derived mesenchymal stromal cells (ASCs) in vitro. We hypothesized that both products would significantly inhibit the growth of Staphylococcus aureus and Escherichia coli. Pooled blood from 10 horses was used for production of EPL. Mesenchymal stromal cells were isolated from adipose tissue harvested from the gluteal region of 3 horses. The study evaluated 3 treatment groups: 10 × EPL, 1.6 million ASCs, and a control, using an incomplete unbalanced block design with repeated measurements. Optical density readings and colony-forming units/mL were calculated at 0, 3, 6, 9, 12, 18, and 24 hours. Decreased bacterial growth was seen at multiple time points for the S. aureus-ASC and S. aureus-EPL treatments, supporting our hypothesis. Increased bacterial growth was noticed in the E. coli-EPL group, with no difference in the E. coli-ASC treatment, which opposed our hypothesis. A clear conclusion of antimicrobial effects of EPL and ASCs cannot be made from this in vitro study. Although it appears that ASCs have a significant effect on decreasing the growth of S. aureus, further studies are needed to explore these effects, particularly in Gram-positive bacteria.


L'arthrite septique est considérée comme une urgence médicale. La maladie consécutive à une colonisation bactérienne peut entraîner une morbidité et une mortalité importantes et nécessite un traitement coûteux. Les propriétés antimicrobiennes des thérapies régénératives, y compris les cellules stromales mésenchymateuses et les produits plaquettaires, ont fait l'objet de recherches approfondies en médecine humaine. Bien que moins d'études aient été menées chez les espèces animales, elles ont montré des résultats prometteurs. Le but de cette étude était d'évaluer la suppression bactérienne par le lysat plaquettaire équin (EPL) et les cellules stromales mésenchymateuses adipeuses (ASC) i n vitro. Nous avons émis l'hypothèse que les deux produits inhiberaient de manière significative la croissance de Staphylococcus aureus et d'Escherichia coli. Un pool de sang de 10 chevaux a été utilisé pour la production d'EPL. Des cellules stromales mésenchymateuses ont été isolées à partir de tissu adipeux prélevé dans la région fessière de trois chevaux. L'étude a évalué trois groupes de traitement : 10 × EPL, 1,6 million d'ASC et un témoin, en utilisant un design en blocs non équilibrés incomplets avec des mesures répétées. Les lectures de densité optique et les unités formatrices de colonie/mL ont été calculées à 0, 3, 6, 9, 12, 18 et 24 heures. Une diminution de la croissance bactérienne a été observée à plusieurs moments pour les traitements S. aureus-ASC et S. aureus-EPL, soutenant notre hypothèse. Une croissance bactérienne accrue a été remarquée dans le groupe E. coli-EPL, sans différence dans le traitement E. coli-ASC, ce qui s'opposait à notre hypothèse. Une conclusion claire des effets antimicrobiens de l'EPL et des ASC ne peut pas être tirée de cette étude in vitro. Bien qu'il semble que les ASC aient un effet significatif sur la diminution de la croissance de S. aureus, d'autres études sont nécessaires pour explorer ces effets, en particulier chez les bactéries à Gram positif.(Traduit par Docteur Serge Messier).


Assuntos
Plaquetas , Escherichia coli , Células-Tronco Mesenquimais , Staphylococcus aureus , Tecido Adiposo , Animais , Plaquetas/microbiologia , Escherichia coli/crescimento & desenvolvimento , Cavalos , Células-Tronco Mesenquimais/microbiologia , Staphylococcus aureus/crescimento & desenvolvimento
15.
Microbiol Spectr ; 10(1): e0086021, 2022 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-35019682

RESUMO

Human neutrophil peptide-1 (HNP-1) is a promising antibiotic candidate, but its clinical applications have been hampered by challenges during mass production and an inadequate understanding of its bactericidal mechanisms. In this study, we demonstrated that Escherichia coli expressing full-length preproHNP-1 secretes a soluble form of HNP-1, which can be recovered from the total cell lysate after isopropyl thio-ß-d-galactoside (IPTG) induction and ultrafiltration. Label-free quantitative proteomics and co-immunoprecipitation experiments revealed that HNP-1 induces cell apoptosis in bacteria by causing DNA and membrane damage. Notably, we found that HNP-1 disrupts the DNA damage response pathway by interfering with the binding of RecA to single-stranded DNA (ssDNA). Further experiments demonstrated that HNP-1 encapsulated in liposomes inhibits the growth of methicillin-resistant Staphylococcus aureus (MRSA) and meropenem-resistant Pseudomonas aeruginosa (MRPA). These results indicated that recombinant protein expression may be a simple and cost-effective solution to produce HNP-1 and that RecA inhibition via HNP-1 may serve as an alternative strategy to counteract antibiotic resistance. IMPORTANCE Human neutrophil peptide-1 (HNP-1) is a promising antibiotic candidate, but its clinical application has been hampered by the difficulty of mass production and an inadequate understanding of its bactericidal mechanisms. In this study, we demonstrated that recombinant protein expression combined with ultrafiltration may be a simple and cost-effective solution to HNP-1 production. We further found that HNP-1 induces bacterial apoptosis and prevents its SOS repair pathway from binding to the RecA protein, which may be a new antibacterial mechanism. In addition, we showed that HNP-1 encapsulated in liposomes inhibits the growth of methicillin-resistant Staphylococcus aureus (MRSA) and meropenem-resistant Pseudomonas aeruginosa (MRPA). These results provide new insights into the production and antibacterial mechanism of HNP-1, both of which may promote its clinical application.


Assuntos
Antibacterianos/farmacologia , Escherichia coli/metabolismo , alfa-Defensinas/genética , alfa-Defensinas/farmacologia , Antibacterianos/metabolismo , Farmacorresistência Bacteriana , Escherichia coli/genética , Humanos , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/crescimento & desenvolvimento , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , alfa-Defensinas/metabolismo
16.
Nat Commun ; 13(1): 197, 2022 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-35017467

RESUMO

To dissect the antibiotic role of nanostructures from chemical moieties belligerent to both bacterial and mammalian cells, here we show the antimicrobial activity and cytotoxicity of nanoparticle-pinched polymer brushes (NPPBs) consisting of chemically inert silica nanospheres of systematically varied diameters covalently grafted with hydrophilic polymer brushes that are non-toxic and non-bactericidal. Assembly of the hydrophilic polymers into nanostructured NPPBs doesn't alter their amicability with mammalian cells, but it incurs a transformation of their antimicrobial potential against bacteria, including clinical multidrug-resistant strains, that depends critically on the nanoparticle sizes. The acquired antimicrobial potency intensifies with small nanoparticles but subsides quickly with large ones. We identify a threshold size (dsilica ~ 50 nm) only beneath which NPPBs remodel bacteria-mimicking membrane into 2D columnar phase, the epitome of membrane pore formation. This study illuminates nanoengineering as a viable approach to develop nanoantibiotics that kill bacteria upon contact yet remain nontoxic when engulfed by mammalian cells.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana/efeitos dos fármacos , Nanopartículas/química , Antibacterianos/síntese química , Eritrócitos , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/ultraestrutura , Células HEK293 , Hemólise/efeitos dos fármacos , Humanos , Interações Hidrofóbicas e Hidrofílicas , Testes de Sensibilidade Microbiana , Nanopartículas/ultraestrutura , Especificidade de Órgãos , Tamanho da Partícula , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus aureus/ultraestrutura
17.
Dermatology ; 238(1): 109-120, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-33887725

RESUMO

BACKGROUND: The pathophysiology in atopic dermatitis (AD) is not fully understood, but immune dysfunction, skin barrier defects, and alterations of the skin microbiota are thought to play important roles. AD skin is frequently colonized with Staphylococcus aureus (S. aureus) and microbial diversity on lesional skin (LS) is reduced compared to on healthy skin. Treatment with narrow-band ultraviolet B (nb-UVB) leads to clinical improvement of the eczema and reduced abundance of S. aureus. However, in-depth knowledge of the temporal dynamics of the skin microbiota in AD in response to nb-UVB treatment is lacking and could provide important clues to decipher whether the microbial changes are primary drivers of the disease, or secondary to the inflammatory process. OBJECTIVES: To map the temporal shifts in the microbiota of the skin, nose, and throat in adult AD patients after nb-UVB treatment. METHODS: Skin swabs were taken from lesional AD skin (n = 16) before and after 3 treatments of nb-UVB, and after 6-8 weeks of full-body treatment. We also obtained samples from non-lesional skin (NLS) and from the nose and throat. All samples were characterized by 16S rRNA gene sequencing. RESULTS: We observed shifts towards higher diversity in the microbiota of lesional AD skin after 6-8 weeks of treatment, while the microbiota of NLS and of the nose/throat remained unchanged. After only 3 treatments with nb-UVB, there were no significant changes in the microbiota. CONCLUSION: Nb-UVB induces changes in the skin microbiota towards higher diversity, but the microbiota of the nose and throat are not altered.


Assuntos
Dermatite Atópica/microbiologia , Dermatite Atópica/radioterapia , Microbiota/efeitos da radiação , Pele/microbiologia , Terapia Ultravioleta , Adulto , Idoso , Biodiversidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nariz/microbiologia , Faringe/microbiologia , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus aureus/efeitos da radiação , Resultado do Tratamento , Adulto Jovem
18.
J Thorac Cardiovasc Surg ; 163(3): 841-849.e1, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33478833

RESUMO

INTRODUCTION: High-dose nitric oxide (NO) has been shown effective against a variety of micro-organisms in vitro, including common bacteria found in donor organs. However, clinical obstacles related to its implementation in vivo are the formation of methemoglobin and the accumulation of toxic nitrogen compounds. Ex vivo lung perfusion (EVLP) is a platform that allows for organ maintenance with an acellular perfusion solution, thus overcoming these limitations. The present study explores the safety of continuous high-dose inhaled (iNO) during EVLP for an extended period of 12 hours. METHODS: Lungs procured from Yorkshire pigs were randomized into control (standard ventilation) and treatment (standard ventilation + 200 ppm iNO) groups, then perfused with an acellular solution for 12 hours (n = 4/group). Lung physiology and biological markers were evaluated. RESULTS: After 12 hours of either standard EVLP or EVLP + 200 ppm iNO, we did not notice any significant physiologic difference between the groups: pulmonary oxygenation (P = .586), peak airway pressures (P = .998), and dynamic (P = .997) and static (P = .908) lung compliances. In addition, no significant differences were seen among proinflammatory cytokines measured in perfusate and lung tissue. Importantly, most common toxic compounds were kept at safe levels throughout the treatment course. CONCLUSIONS: High-dose inhaled NO delivered continuously over 12 hours appears to be safe without inducing any significant pulmonary inflammation or deterioration in lung function. These findings support further efficacy studies to explore the use of iNO for the treatment of infections in donor lungs during EVLP.


Assuntos
Anti-Infecciosos/administração & dosagem , Infecções Bacterianas/prevenção & controle , Circulação Extracorpórea , Pulmão/irrigação sanguínea , Pulmão/efeitos dos fármacos , Óxido Nítrico/administração & dosagem , Preservação de Órgãos , Perfusão , Administração por Inalação , Animais , Anti-Infecciosos/toxicidade , Infecções Bacterianas/microbiologia , Burkholderia cepacia/efeitos dos fármacos , Burkholderia cepacia/crescimento & desenvolvimento , Circulação Extracorpórea/efeitos adversos , Estudos de Viabilidade , Pulmão/microbiologia , Pulmão/cirurgia , Masculino , Metemoglobina/metabolismo , Modelos Animais , Óxido Nítrico/toxicidade , Preservação de Órgãos/efeitos adversos , Perfusão/efeitos adversos , Pneumonectomia , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/crescimento & desenvolvimento , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Sus scrofa
19.
Appl Biochem Biotechnol ; 194(1): 464-478, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34611854

RESUMO

Nanoparticle research is fascinating and getting hold of consequences due to the wide variety of applications in the biomedical field. Green synthesis of nanoparticles is a cost-effective and eco-friendly approach. It can be synthesised using fungi, algae, plant, yeast, bacteria, microbial enzymes etc. Our current research study focuses on the green synthesis of silver nanoparticles using seed extract of Cassia tora. The colour change from yellow to red colour confirms the formation of silver nanoparticles. The synthesised silver nanoparticles were characterised by Ultraviolet-Visible spectroscopy, Fourier-transform infrared (FTIR), X-ray diffraction analysis (XRD), Scanning Electron Microscopy (SEM) and antibacterial efficacy against three different strains were analysed. The surface plasmon resonance of synthesised AgNPs using Cassia tora seed extract shows maximum absorption peak at 423 nm in UV-visible spectroscopy. X-ray diffraction displays the crystalline nature of synthesised AgNPs and they exhibited four distinct peaks at 36.69°, 42.92°, 63.27° and 76.46°. The particle size of synthesised AgNPs observed through SEM was found to be 55.80 nm, 58.97 nm, 61.06 nm, 63.26 nm and 64.80 nm. S.aureus exhibited maximum zone of inhibition of 12 mm and 13 mm when treated with 25 and 50 µl of the synthesised nanoparticles. Thus, the green synthesised silver nanoparticle using Cassia tora seed extract proved to possess strong anti-bacterial activity.


Assuntos
Antibacterianos , Cassia/química , Nanopartículas Metálicas/química , Extratos Vegetais/química , Sementes/química , Prata , Staphylococcus aureus/crescimento & desenvolvimento , Antibacterianos/síntese química , Antibacterianos/química , Antibacterianos/farmacologia , Química Verde , Prata/química , Prata/farmacologia
20.
Int J Biol Macromol ; 195: 49-58, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34856218

RESUMO

This study aimed to develop a plasticized starch (PS) based film loaded with chitosan nanoparticles (CNPs, 1, 2, 3, and 4%) as a reinforcing and antibacterial agent. We examined the morphology, biodegradability, mechanical, thermo-mechanical, and barrier properties of the PS/CNPs films. The antimicrobial activity against both Gram-positive (S. aureus) and Gram-negative (E. coli) bacteria was investigated by colony forming unit (CFU) and disc diffusion methods. A dense structure was obtained for all PS/CNPs films and, thus, their complete biodegradation occurred in more days than neat PS. The increase in the CNPs percentage led to improved mechanical behaviour and barrier properties. PS-CNPs composite films revealed inhibition zones against both E. coli and S. aureus, with the 100% reduction in CFU against S. aureus. The current study exhibited that PS-CNPs films were more effective in inhibiting bacteria growth than neat PS film, confirming the composite films potential application as antimicrobial food packaging.


Assuntos
Anti-Infecciosos/farmacologia , Plásticos Biodegradáveis/farmacologia , Quitosana/farmacologia , Amido/química , Anti-Infecciosos/síntese química , Anti-Infecciosos/química , Plásticos Biodegradáveis/síntese química , Plásticos Biodegradáveis/química , Quitosana/síntese química , Quitosana/química , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Embalagem de Alimentos , Nanocompostos , Tamanho da Partícula , Permeabilidade , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento
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