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1.
Food Chem ; 308: 125682, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-31655479

RESUMO

In this work, a multifunctional food packaging composite coating with transparent, biodegradable, antifogging and antibacterial properties was designed and fabricated by quaternary ammonium salt modified chitosan (HACC) and poly (vinyl alcohol) (PVA) via a facile and environment-friendly solution casting method. A simple quaternization modification enabled the coating simultaneously to achieve excellent antifogging and antibacterial functions. The excellent antifogging property of the HACC/PVA composite coating was attributed to the strong water absorbency of quaternary ammonium chitosan and PVA. A nearly 98% transmittance ratio of coated glasses was achieved during antifogging test. In addition, the inhibition rate of the HACC/PVA composite coating kill against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and Botrytis cinerea were up to ~99%. The antibacterial effect was demonstrated by each group of strawberries after storage for 1, 3, 5 days. The multifunctional coating has broad prospects in the application of fruit and vegetable packaging.


Assuntos
Compostos de Amônio/química , Antibacterianos/farmacologia , Quitosana/farmacologia , Embalagem de Alimentos , Quitosana/química , Escherichia coli/efeitos dos fármacos , Compostos de Amônio Quaternário , Staphylococcus aureus/efeitos dos fármacos
2.
J Colloid Interface Sci ; 559: 197-205, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31627143

RESUMO

Mesoporous silica nanoparticle (MSN) demonstrates great potentials as a loading platform for bactericidal agents, but may be limited by its application form of bulk or powder. Herein, we developed MSN surface-enriched composite membranes with remarkable photodynamic antimicrobial activities via a facile electrospinning method. The mixture of zein and polycaprolactone (PCL) was served as the polymeric matrix, while the methylene blue (MB) loaded MSN was modified by trichloro (1H, 1H, 2H, 2H-heptadecafluorodecyl) silane (THFS) and acted as reactive oxygen species (ROS) generator to exert their antimicrobial performances. Owing to its low surface energy, the fluorinated MSN tended to be enriched on the surface of the nanofiber, hence significantly enhancing the ROS generation. Moreover, benefiting from the surface enrichment of the fluorinated nanoparticles, the composite membrane displayed obvious surface hydrophobicity and exhibited discernible bacterial repellency. Subsequently, upon visible light (660 nm) irradiation, the composite membrane demonstrated remarkable photodynamic antibacterial activities against Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli) but without essential detrimental impacts on the mammalian cells. We envision that this self-enriched MSN composite membrane may find broad applications in bacterial infection-resistant areas.


Assuntos
Anti-Infecciosos/química , Azul de Metileno/química , Nanopartículas/química , Fotoquimioterapia/métodos , Dióxido de Silício/química , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Fibroblastos/citologia , Flúor/química , Interações Hidrofóbicas e Hidrofílicas , Luz , Camundongos , Poliésteres/química , Porosidade , Espécies Reativas de Oxigênio/metabolismo , Staphylococcus aureus/efeitos dos fármacos , Propriedades de Superfície , Zeína/química
3.
J Colloid Interface Sci ; 559: 313-323, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31675662

RESUMO

Antibiotic resistance is a common phenomenon observed during treatment with antibacterials. Use of nanozymes, especially those with synergistic enzyme-like activities, as antibacterials could overcome this problem, but their synthesis is limited by their high cost and/or complex production process. Herein, vanadium oxide nanodots (VOxNDs) were prepared via a one-step bottom-up ethanol-thermal method using vanadium trichloride as the precursor. VOxNDs alone possess bienzyme mimics of peroxidase and oxidase. Accordingly, highly efficient antibacterials against drug-resistant bacteria can be obtained through synergistic catalysis; the oxidase-like activity decomposes O2 to generate superoxide anion radical (O2-) and hydroxyl radicals (OH), and the intrinsic peroxidase-like activity can further induce the production of OH from external H2O2. Consequently, H2O2 concentration could decrease up to four magnitude orders with VOxNDs to achieve an antibacterial efficacy similar to that of H2O2 alone. Wound healing in vivo further confirms the high antibacterial efficiency, good biocompatibility, and application potential of the synergistic antibacterial system due to the "nano" structure of VOxNDs. The method of synthesis of nanodot antibacterials described in this paper is inexpensive, and the results of this study reveal the multi-enzymatic synergism of nanozymes.


Assuntos
Antibacterianos/química , Nanopartículas Metálicas/química , Óxidos/química , Compostos de Vanádio/química , Cicatrização/efeitos dos fármacos , Animais , Materiais Biocompatíveis/química , Materiais Biomiméticos/química , Catálise , Sobrevivência Celular/efeitos dos fármacos , Farmacorresistência Bacteriana/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Células HeLa , Células Endoteliais da Veia Umbilical Humana , Humanos , Peróxido de Hidrogênio/química , Radical Hidroxila/química , Peroxidases/metabolismo , Ratos Sprague-Dawley , Staphylococcus aureus/efeitos dos fármacos
4.
J Sci Food Agric ; 100(1): 335-342, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31584691

RESUMO

BACKGROUND: Antibacterial activity of honey is not only crucial characteristic in selection of honey for medical usage but also an important honey quality marker. The aim of the study was to characterise the antibacterial potential of 29 honey samples representing the main types of multi-floral blossom and honeydew honeys produced in Switzerland. Antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa was expressed as a minimum inhibitory and bactericidal concentrations (MIC and MBC). Furthermore, the content of bee-derived glucose oxidase (GOX) and its enzymatic product, H2 O2 , were also evaluated. RESULTS: All honey samples successfully met basic defined criteria (moisture and hydroxymethylfurfural (HMF)) tested in this study. Honeydew honeys were the most effective honey samples and generated the highest levels of H2 O2 . A strong significant correlation was found between the overall antibacterial activity and the level of H2 O2 among all honey samples. Interestingly, the content of GOX in honey samples did not correlate with their antibacterial activity as well as H2 O2 production capacity. A weak antibacterial activity was determined in five floral honeys, most likely due to increased enzymatic activity of pollen-derived catalase. CONCLUSION: This study showed that antibacterial effect of Swiss honey samples is associated mainly with H2 O2 . © 2019 Society of Chemical Industry.


Assuntos
Antibacterianos/análise , Mel/análise , Animais , Antibacterianos/farmacologia , Abelhas , Catalase/análise , Glucose Oxidase/análise , Mel/classificação , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Suíça
5.
Arch Insect Biochem Physiol ; 103(1): e21626, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31562754

RESUMO

Insects can produce various antimicrobial peptides (AMPs) upon immune stimulation. One class of AMPs are characterized by their high proline content in certain fragments. They are generally called proline-rich antimicrobial peptides (PrAMPs). We previously reported the characterization of Spodoptera litura lebocin-1 (SlLeb-1), a PrAMP proprotein. Preliminary studies with synthetic polypeptides showed that among the four deductive active fragments, the C-terminal fragment SlLeb-1 (124-158) showed strong antibacterial activities. Here, we further characterized the antibacterial and antifungal activities of 124-158 and its four subfragments: 124-155, 124-149, 127-158, and 135-158. Only 124-158 and 127-158 could agglutinate bacteria, while 124-158 and four subfragments all could agglutinate Beauveria bassiana spores. Confocal microscopy showed that fluorescent peptides were located on the microbial surface. Fragment 135-158 lost activity completely against Escherichia coli and Staphylococcus aureus, and partially against Bacillus subtilis. Only 124-149 showed low activity against Serratia marcescens. Negative staining, transmission, and scanning electron microscopy of 124-158 treated bacteria showed different morphologies. Flow cytometry analysis of S. aureus showed that 124-158 and four subfragments changed bacterial subpopulations and caused an increase of DNA content. These results indicate that active fragments of SlLeb-1 may have diverse antimicrobial effects against different microbes. This study may provide an insight into the development of novel antimicrobial agents.


Assuntos
Peptídeos Catiônicos Antimicrobianos/farmacologia , Proteínas de Insetos/farmacologia , Spodoptera/química , Animais , Peptídeos Catiônicos Antimicrobianos/química , Bacillus subtilis/efeitos dos fármacos , Beauveria/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Proteínas de Insetos/química , Serratia marcescens/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos
6.
Cell Physiol Biochem ; 53(6): 1015-1028, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31854953

RESUMO

BACKGROUND/AIMS: Pulmonary infections with Pseudomonas aeruginosa (P. aeruginosa) or Staphylococcus aureus (S. aureus) are of utmost clinical relevance in patients with cystic fibrosis, chronic obstructive pulmonary disease, after trauma and burn, upon ventilation or in immuno-compromised patients. Many P. aeruginosa and S. aureus strains are resistant to many known antibiotics and it is very difficult or often impossible to eradicate the pathogens in patient´s lungs. We have recently shown that the sphingoid base sphingosine very efficiently kills many pathogens, including for instance P. aeruginosa, S. aureus or Acinetobacter baumannii, in vitro. In vivo experiments of our group on cystic fibrosis mice indicated that inhalation of sphingosine prevents or eliminates existing acute or chronic pneumonia with P. aeruginosa or S. aureus in these mice. We also demonstrated that sphingosine is safe to use for inhalation up to high doses, at least in mice. To facilitate development of sphingosine to an anti-bactericidal drug that can be used in humans for inhalation, safety data on non-rodents, larger animals are absolutely required. METHODS: Here, we inhaled mini pigs with increasing doses of sphingosine for 10 days and analyzed the uptake of sphingosine into epithelial cells of bronchi as well as into the trachea and lung and the systemic circulation. Moreover, we measured the generation of ceramide and sphingosine 1-phosphate that potentially mediate inflammation, the influx of leukocytes, epithelial cell death and disruption of the epithelial cell barrier. RESULTS: We demonstrate that inhalation of sphingosine results in increased levels of sphingosine in the luminal membrane of bronchi and the trachea, but not in systemic accumulation. Inhaled sphingosine had no side effects up to very high doses. CONCLUSION: In summary, we demonstrate that inhalation of sphingosine results in an increase of sphingosine concentrations in the luminal plasma membrane of tracheal and bronchial epithelial cells. The inhalation has no systemic or local side effects.


Assuntos
Antibacterianos/metabolismo , Esfingosina/metabolismo , Administração por Inalação , Animais , Antibacterianos/farmacologia , Brônquios/metabolismo , Brônquios/patologia , Ceramidas/análise , Humanos , Pulmão/patologia , Lisofosfolipídeos/análise , Espectrometria de Massas , Pseudomonas aeruginosa/efeitos dos fármacos , Esfingosina/análogos & derivados , Esfingosina/análise , Esfingosina/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Suínos , Porco Miniatura , Traqueia/metabolismo , Traqueia/patologia
7.
Pol J Microbiol ; 68(4): 477-491, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31880892

RESUMO

This study explored a potential treatment against methicillin-resistant Staphylococcus aureus (MRSA) infections that combines thioridazine (TZ), an efflux pump inhibitor, and miconazole (MCZ), an autolysis inducer, with the anti-microbial drug cloxacillin (CXN). In vitro, the combination treatment of TZ and MCZ significantly reduced 4096-fold (Σ (FIC) = 0.1 - 1.25) the MIC value of CXN against S. aureus. In vivo, the combination therapy significantly relieved breast redness and swelling in mice infected with either clinical or standard strains of S. aureus. Meanwhile, the number of bacteria isolated from the MRSA135-infected mice decreased significantly (p = 0.0427 < 0.05) after the combination therapy when compared to monotherapy. Moreover, the number of bacteria isolated from the mice infected with a reference S. aureus strain also decreased significantly (p = 0.0191 < 0.05) after the combination therapy when compared to monotherapy. The pathological changes were more significant in the CXN-treated group when compared to mice treated with a combination of three drugs. In addition, we found that combination therapy reduced the release of the bacteria-stimulated cytokines such as IL-6, IFN-γ, and TNF-α. Cytokine assays in serum revealed that CXN alone induced IL-6, IFN-γ, and TNF-α in the mouse groups infected with ATCC 29213 or MRSA135, and the combination of these three drugs significantly reduced IL-6, IFN-γ, and TNF-α concentrations. Also, the levels of TNF-α and IFN-γ in mice treated with a combination of three drugs were significantly lower than in the CXN-treated group. Given the synergistic antibacterial activity of CXN, we concluded that the combination of CXN with TZ, and MCZ could be developed as a novel therapeutic strategy against S. aureus.This study explored a potential treatment against methicillin-resistant Staphylococcus aureus (MRSA) infections that combines thioridazine (TZ), an efflux pump inhibitor, and miconazole (MCZ), an autolysis inducer, with the anti-microbial drug cloxacillin (CXN). In vitro, the combination treatment of TZ and MCZ significantly reduced 4096-fold (Σ (FIC) = 0.1 ­ 1.25) the MIC value of CXN against S. aureus. In vivo, the combination therapy significantly relieved breast redness and swelling in mice infected with either clinical or standard strains of S. aureus. Meanwhile, the number of bacteria isolated from the MRSA135-infected mice decreased significantly (p = 0.0427 < 0.05) after the combination therapy when compared to monotherapy. Moreover, the number of bacteria isolated from the mice infected with a reference S. aureus strain also decreased significantly (p = 0.0191 < 0.05) after the combination therapy when compared to monotherapy. The pathological changes were more significant in the CXN-treated group when compared to mice treated with a combination of three drugs. In addition, we found that combination therapy reduced the release of the bacteria-stimulated cytokines such as IL-6, IFN-γ, and TNF-α. Cytokine assays in serum revealed that CXN alone induced IL-6, IFN-γ, and TNF-α in the mouse groups infected with ATCC 29213 or MRSA135, and the combination of these three drugs significantly reduced IL-6, IFN-γ, and TNF-α concentrations. Also, the levels of TNF-α and IFN-γ in mice treated with a combination of three drugs were significantly lower than in the CXN-treated group. Given the synergistic antibacterial activity of CXN, we concluded that the combination of CXN with TZ, and MCZ could be developed as a novel therapeutic strategy against S. aureus.


Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/antagonistas & inibidores , Farmacorresistência Bacteriana , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/efeitos dos fármacos , beta-Lactamas/farmacologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Bacteriólise/efeitos dos fármacos , Cloxacilina/farmacologia , Quimioterapia Combinada , Humanos , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Miconazol/farmacologia , Testes de Sensibilidade Microbiana , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/citologia , Staphylococcus aureus/genética , Staphylococcus aureus/metabolismo , Tioridazina/farmacologia
8.
Pol J Microbiol ; 68(4): 541-548, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31880897

RESUMO

Analysis of the epidemiology of Staphylococcus aureus (SA) ocular infections and virulence factors of the isolates with a special emphasis on their drug resistance, and the ability of biofilm formation. In a period from 2009 to 2013, 83 isolates of SA were prospectively collected and preserved in a multicenter laboratory-based study carried out in southern Poland. Epidemiological, phenotypic, and genotypic analyses were performed. The resistance and virulence genes were analyzed. Screening for the biofilm formation was provided. Among the materials derived from ocular infections from 456 patients, SA was found in 18.2% (n = 83) of cases (one SA isolate per one patient). Most infections were identified in the age group of over 65 years (OR 8.4 95%CI; 1.03-68.49). The majority of patients (73.4%) were hospitalized. Among the virulence and resistance genes, the most frequently detected were the lukE (72.2%, n = 60) and ermA (15.6%, n = 13) genes. A positive result of the CRA test (the ability of biofilm formation) was found in 66.2% (n = 55) of isolates. Among the strains under study, 6.0% (n = 5) had the methicillin-resistant Staphylococcus aureus phenotype, and 26.5% (n = 22) had the macrolide-lincosamide-streptogramin B phenotype. In 48 (57.8%) isolates the neomycin resistance was revealed. All isolates under study were sensitive to vancomycin. The population most susceptible to ocular SA infections consists of hospitalized patients aged 65 and more. The SA strains under study showed the increased ability to biofilm formation. In the strains tested, high susceptibility to chloramphenicol and fluoroquinolones was demonstrated. However, the high level of drug resistance to neomycin detected in this study among SA isolates and the blood-ocular barrier makes it difficult to treat ocular infections.Analysis of the epidemiology of Staphylococcus aureus (SA) ocular infections and virulence factors of the isolates with a special emphasis on their drug resistance, and the ability of biofilm formation. In a period from 2009 to 2013, 83 isolates of SA were prospectively collected and preserved in a multicenter laboratory-based study carried out in southern Poland. Epidemiological, phenotypic, and genotypic analyses were performed. The resistance and virulence genes were analyzed. Screening for the biofilm formation was provided. Among the materials derived from ocular infections from 456 patients, SA was found in 18.2% (n = 83) of cases (one SA isolate per one patient). Most infections were identified in the age group of over 65 years (OR 8.4 95%CI; 1.03-68.49). The majority of patients (73.4%) were hospitalized. Among the virulence and resistance genes, the most frequently detected were the lukE (72.2%, n = 60) and ermA (15.6%, n = 13) genes. A positive result of the CRA test (the ability of biofilm formation) was found in 66.2% (n = 55) of isolates. Among the strains under study, 6.0% (n = 5) had the methicillin-resistant Staphylococcus aureus phenotype, and 26.5% (n = 22) had the macrolide-lincosamide-streptogramin B phenotype. In 48 (57.8%) isolates the neomycin resistance was revealed. All isolates under study were sensitive to vancomycin. The population most susceptible to ocular SA infections consists of hospitalized patients aged 65 and more. The SA strains under study showed the increased ability to biofilm formation. In the strains tested, high susceptibility to chloramphenicol and fluoroquinolones was demonstrated. However, the high level of drug resistance to neomycin detected in this study among SA isolates and the blood-ocular barrier makes it difficult to treat ocular infections.


Assuntos
Proteínas de Bactérias/genética , Farmacorresistência Bacteriana , Infecções Oculares/microbiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/genética , Fatores de Virulência/genética , Adolescente , Adulto , Idoso , Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , Criança , Infecções Oculares/epidemiologia , Feminino , Humanos , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Polônia/epidemiologia , Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus/classificação , Staphylococcus aureus/metabolismo , Fatores de Virulência/metabolismo , Adulto Jovem
9.
J Photochem Photobiol B ; 201: 111651, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31683166

RESUMO

Designing biomimetic biomaterials influenced by the common complex structure of hard tissues is yet a test these days. The control of bio-mineralization procedure onto biomaterials should be assessed before the use in medical applications. Coming to the bone rejuvenation applications, this work assessed the in vitro antibacterial activity and interacting between osteoblast cells (MG63) on poly (hydroxypropyl methacrylate) (PHPMA) cryogel consolidated with Zn/Ce substituted hydroxyapatite (MHAp) nanocomposite (PHPMA/MHAp). Osteoblast cell multiplication, morphology, and metabolic action were assessed through various conventions. The functional group, texture, mechanical properties, and protein adsorption profiles of the fabricated nanocomposite were analyzed by the FTIR, XRD, SEM, and mechanical examinations, respectively. The bacterial activity of nanocomposites was additionally assessed against E. coli and S. aureus microorganisms, individually. Nanocomposite advanced endo-chondral ossification at the messed up parts of the bone deformity than cryogel did. These results recommend that PHPMA/MHAp nanocomposites joined the good innate properties of each polymer and bioceramic, giving a mechanically powerful, cell-responsive, and permeable stage for hard tissue applications.


Assuntos
Criogéis/química , Durapatita/química , Fraturas do Fêmur/terapia , Nanocompostos/química , Nanopartículas/química , Animais , Regeneração Óssea/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Cério/química , Modelos Animais de Doenças , Escherichia coli/efeitos dos fármacos , Fraturas do Fêmur/patologia , Nanocompostos/uso terapêutico , Nanocompostos/toxicidade , Polímeros/química , Ratos , Staphylococcus aureus/efeitos dos fármacos , Engenharia Tecidual , Zinco/química
10.
Mymensingh Med J ; 28(4): 767-772, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31599239

RESUMO

Evaluation of the in vitro antibacterial activity of the ethanolic extract isolated from Cinnamomum zeylanicum bark against two food borne pathogens, Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. This experimental study was carried out in the department of Pharmacology & Therapeutics in collaboration with the department of Microbiology, Mymensingh Medical College, Mymensingh, Bangladesh from July 2017 to July 2018. The antibacterial activity was tested at different concentrations of extracts of spice by using disc diffusion method. The extracts were prepared by using a solvent ethanol. The test microorganisms were also tested for their activity against a standard antibiotic Amikacin (500mg) by disc diffusion method and the result was compared with that of ethanolic extracts. Cinnamon had inhibitory activity against both Staphylococcus aureus and Escherichia coli. The ethanolic extracts were more effective against Staphylococcus aureus than E. coli. Staphylococcus aureus showed activity from 60% conc. (zone of inhibition 17mm) where E. coli from 80% conc. (ZOI 18mm). Maximum zone of inhibition was 26mm for both the test organisms. This result was also compared to those obtained against a standard antibiotic Amikacin where extract produced wider zone of inhibition of 26mm as compared to Amikacin for both test organisms. The present study showed that ethanolic extract of cinnamon demonstrated stronger antimicrobial effect against food borne pathogens.


Assuntos
Antibacterianos/toxicidade , Cinnamomum zeylanicum , Escherichia coli/efeitos dos fármacos , Extratos Vegetais/toxicidade , Staphylococcus aureus/efeitos dos fármacos , Bangladesh , Etanol , Microbiologia de Alimentos , Humanos
11.
Mymensingh Med J ; 28(4): 779-791, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31599241

RESUMO

Evaluation of the in vitro antibacterial activity of aqueous and ethanolic extracts isolated from Clove (Syzygium aromaticum) buds against three food borne pathogens, gram-positive Staphylococcus aureus and gram-negative Escherichia coli & Pseudomonas aeruginosa. This interventional study was carried out during the period of July 2018 to June 2019 in the Department of Pharmacology and Therapeutics with the collaboration of Department of Microbiology, Mymensingh Medical College, Mymensingh, Bangladesh. The antibacterial activity was tested at different concentrations of both extracts of spice by using disc diffusion & broth dilution method. The extracts were prepared by using solvents aqueous & ethanol. The test microorganisms were also tested for their activity against a standard antibiotic Gentamicin (80mg) by broth dilution method and the result was compared with that of Aqueous and Ethanolic extracts. Aqueous and ethanolic extracts of clove had inhibitory activity against the test bacteria. Among different concentrations of the ACE, 500µg/ml & above concentration showed inhibitory effect against Staphylococcus aureus & Escherichia coli and 700µg/ml & above concentration showed inhibitory effect against Pseudomonas aeruginosa. In case of ECE, 500µg/ml & above concentration showed inhibitory effect against aforesaid bacteria. In disc diffusion method, S. aureus was found to be most susceptible to ACE (30.5mm) & Pseudomonas aeruginosa was found to be most susceptible to ECE (38mm). Minimum inhibitory concentrations (MIC) of ECE were lower than ACE for the test bacteria except Staphylococcus aureus where MICs of ACE & ECE were the same. This result was also compared against a standard antibiotic Gentamicin where the MICs of Gentamicin were lower in comparison to MICs of ACE & ECE. The present study showed that aqueous and ethanolic extracts of Clove demonstrated antibacterial effects against food borne pathogens.


Assuntos
Antibacterianos/toxicidade , Extratos Vegetais/toxicidade , Syzygium , Bangladesh , Escherichia coli/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos
13.
J Photochem Photobiol B ; 200: 111646, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31655457

RESUMO

Antimicrobial Photodynamic Therapy (aPDT) is an alternative to conventional treatments of local infections such as the use of antibiotics, which may lead to the development of resistance. aPDT besides requiring the use of a photosensitiser also needs a light source do be carried out. In the search for efficient and low-cost procedure the use of multispectral polarized light (λ400-2000 nm) emerges as a possibility for the execution of aPDT. The use of a highly effective photosensitizer is also of great importance. 1,9-Dimethyl-Methylene Blue Zinc Chloride Double Salt - DMMB is a potent phenothiazine derivative that presents high photodynamic action due to its high lipophilicity as well as a greater quantum yield of Singlet oxygen and phototoxicity when compared to other Photosensitizers. The aim of this study was to assess, In Vitro, the efficacy of aPDT on Staphylococcus aureus (ATCC 25923) using different concentrations of DMMB associated to a Polarized light source (Bioptron®, 40 mW, ᴓ = 15.8 cm2) using different energy densities. Based on the IC50, 150 and 300 ng/mL of DMMB concentrations were chosen for this study. Twelve experimental groups were used: (Control, PLs, PSs and aPDTs). Serial dilutions (up to 10-8) of the bacterial inoculum were used and the DMMB was added using the two previously determined concentrations. After 5 min of preincubation the dilutions of the inoculum were illuminated by the polarized light source. Subsequently, 100 µL of each dilution, in triplicate, were inoculated into Petri dishes containing TSA medium and incubated in a bacteriological oven at 37 °C for 24-h and quantification of UFCs was done. The results showed significant exponential reduction (p < .0001) of 99.93% (150 ng/mL + LP 10 J/cm2) and 99.97% (300 ng/mL + LP 5 J/cm2) the CFU counts in comparison to non-illuminated control. The results of this study allow to conclude that aPDT carried out with 1,9-Dimethyl-Methylene Blue Zinc Chloride Double Salt-DMMB and a PL souce was efficacious on the reduction (99.97%), in vitro, of the bacterial counts of S. aureus.


Assuntos
Anti-Infecciosos/farmacologia , Cloretos/química , Azul de Metileno/análogos & derivados , Fármacos Fotossensibilizantes/química , Staphylococcus aureus/efeitos dos fármacos , Compostos de Zinco/química , Anti-Infecciosos/química , Luz , Azul de Metileno/química , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia
14.
Fitoterapia ; 138: 104350, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31473333

RESUMO

Three new bibenzyl derivatives (bletstrins A-C, 1-3), including two bibenzyls that have hydroxyl-substituted chiral centers on the aliphatic bibenzyl bridge, along with eighteen known stilbenoids (4-21) were isolated from the tubers of Bletilla striata. The structures of new compounds were elucidated by the use of 1D/2D NMR spectroscopic data. The absolute configurations of bletitrins A and B were determined by optical rotation value. Compounds 13-16 were isolated from the Orchidaceae for the first time. Most of the isolated compounds were evaluated for their antibacterial activities against three gram-positive bacterial strains and one gram-negative bacterial strain. Compounds 4, 10, 12, 14, 15, 16 and 18 showed potent inhibitory activities, with MICs of (6-52 µg/mL) against S. aureus ATCC 6538.


Assuntos
Antibacterianos/farmacologia , Orchidaceae/química , Tubérculos/química , Estilbenos/farmacologia , Antibacterianos/isolamento & purificação , Bibenzilas/isolamento & purificação , Bibenzilas/farmacologia , China , Testes de Sensibilidade Microbiana , Estrutura Molecular , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Estilbenos/isolamento & purificação
15.
J Agric Food Chem ; 67(39): 10863-10870, 2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31507180

RESUMO

Mastitis, inflammation of the mammary gland, occurs in both humans and animals. Staphylococcus aureus is the most common infectious bacterial pathogen associated with mastitis. We investigated the effects of allicin on S. aureus-induced mastitis in mice. Pathological histology revealed that allicin inhibited S. aureus-induced pathological damage and myeloperoxidase activity in mammary tissues. Enzyme-linked immunosorbent assays demonstrated that allicin reduced the production of IL-1ß and TNF-α as well as inhibited the NF-κB and mitogen-activated protein kinase pathway by reducing phosphorylation of p65, IκBα, p38, JNK, and ERK. Western blotting revealed that allicin reduced TLR2 and TLR6 expression in mammary tissues and cells but not in HEK293 cells. The lipid raft content was reduced by allicin, which inhibited signaling downstream of TLR2 and TLR6. Liver X receptor α (LXRα) luciferase reporter assays and LXRα interference experiments showed that allicin improved the LXRα activity and adenosine 5'-triphosphate-binding cassette G and A1 (ABCG and ABCA1) expression, thereby reducing the cholesterol level, lipid raft formation, and downstream TLR2 and TLR6 pathway activity. These results demonstrated that allicin exerted anti-inflammatory effects against S. aureus mastitis by improving the LXRα activity and reducing lipid raft formation.


Assuntos
Mastite/tratamento farmacológico , Microdomínios da Membrana/efeitos dos fármacos , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos , Ácidos Sulfínicos/administração & dosagem , Animais , Feminino , Humanos , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Receptores X do Fígado/genética , Receptores X do Fígado/metabolismo , Mastite/genética , Mastite/metabolismo , Mastite/microbiologia , Microdomínios da Membrana/química , Microdomínios da Membrana/genética , Microdomínios da Membrana/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , NF-kappa B/genética , NF-kappa B/metabolismo , Infecções Estafilocócicas/genética , Infecções Estafilocócicas/metabolismo , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/fisiologia , Receptor 2 Toll-Like/genética , Receptor 2 Toll-Like/metabolismo
16.
J Agric Food Chem ; 67(39): 10880-10890, 2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31508956

RESUMO

A sustainable biomass-based nanocomposite hydrogel was formulated, characterized, and applied for curcumin delivery. Phytosynthesized zinc oxide nanoparticles (ZnO NPs) employing musk melon (Cucumis melo) seed extract was embedded in the hydrogel matrices and cross-linked using Dialdehyde cellulose prepared from sugarcane (Saccharum officinarum) bagasse (SCB). Nanoparticle incorporation enhanced the hydrogel's swelling degree to 4048% at pH 4.0. Also, an improved tensile strength of 14.1 ± 0.32 MPa was exhibited by the nanocomposite hydrogel compared to 9.79 ± 0.76 MPa for the pure chitosan cellulose hydrogel. A curcumin loading efficiency of 89.68% with around 30% increased loading was exhibited for the nanocomposite hydrogel. A Fickian diffusion-controlled curcumin release mechanism with maximum release at pH 7.4 was obtained. The synergistic effect on the antimicrobial activity was exhibited against Staphylococcus aureus and Trichophyton rubrum. The in vitro cytotoxicity studies employing L929 cells and A431 cells demonstrated good biocompatibility and enhanced anticancer activity of the curcumin-loaded green nanocomposite hydrogel compared to pure curcumin.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Curcumina/química , Curcumina/farmacologia , Sistemas de Liberação de Medicamentos/métodos , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Celulose/química , Quitosana/química , Cucumis melo/química , Portadores de Fármacos/química , Hidrogéis/química , Nanocompostos/química , Nanopartículas/química , Sementes/química , Staphylococcus aureus/efeitos dos fármacos , Trichophyton/efeitos dos fármacos , Trichophyton/crescimento & desenvolvimento , Óxido de Zinco/química
17.
BMC Infect Dis ; 19(1): 823, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31533647

RESUMO

BACKGROUND: The purpose of this study was to gather temporal trends on bacteria epidemiology and resistance of intraoperative bone culture from chronic ostemyelitis at an affiliated hospital in South China. METHOD: Records of patients with chronic osteomyelitis from 2003 to 2014 were retrospectively reviewed. The medical data were extracted using a unified protocol. Antimicrobial susceptibility testing was carried out by means of a unified protocol using the Kirby-Bauer method, results were analyzed according to Clinical and Laboratory Standards Institute definitions. RESULT: Four hundred eighteen cases met our inclusion criteria. For pathogen distribution, the top five strains were Staphylococcus aureus (27.9%); Pseudomonas aeruginosa (12.1%); Enterobacter cloacae (9.5%); Acinetobacter baumanii (9.0%) and Escherichia coli (7.8%). Bacterial culture positive rate was decreased significantly among different year-groups. Mutiple bacterial infection rate was 28.1%. One strain of Staphylococcus aureus was resistant to linezolid and vancomycin. Resistance of Pseudomonas aeruginosa stains to Cefazolin, Cefuroxime, Cefotaxime, and Cefoxitin were 100% nearly. Resistance of Acinetobacter baumanii stains against Cefazolin, Cefuroxime were 100%. Ciprofloxacin resistance among Escherichia coli isolates increased from 25 to 44.4%. On the contrary, resistance of Enterobacter cloacae stains to Cefotaxime and Ceftazidime were decreased from 83.3 to 36.4%. CONCLUSIONS: From 2003 to 2014, positive rate of intraoperative bone culture of chronic osteomyelitis was decreased; the proportion of Staphylococcus aureus was decreased gradually, and our results indicate the importance of bacterial surveilance studies about chronic osteomyelitis.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana/efeitos dos fármacos , Osteomielite/diagnóstico , Adolescente , Adulto , Antibacterianos/uso terapêutico , Cefotaxima/farmacologia , Cefotaxima/uso terapêutico , China , Doença Crônica , Escherichia coli/efeitos dos fármacos , Escherichia coli/isolamento & purificação , Feminino , Hospitais , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Osteomielite/tratamento farmacológico , Osteomielite/microbiologia , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/isolamento & purificação , Estudos Retrospectivos , Rifampina/farmacologia , Rifampina/uso terapêutico , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/isolamento & purificação , Adulto Jovem
18.
Int J Nanomedicine ; 14: 5977-5987, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31534332

RESUMO

Background: Nowadays, zirconia ceramic implants are widely used as a kind of hip prosthesis material because of their excellent biocompatibility and long-term wear resistance. However, the hip joint is one of the major joints with complex 3D morphological structure and greatly individual differences, which usually causes great material waste during the process of surgical selection of prosthesis. Methods: In this paper, by combining ceramic 3D printing technology with antibacterial nano-modification, zirconia ceramic implant material was obtained with precise 3D structure and effective antibacterial properties. Among which, two technical problems (fragile and sintering induced irregular shrinkage) of 3D printed ceramics were effectively minimized by optimizing the reaction conditions and selective area inversing compensation. Through in vivo and in vitro experiments, it was confirmed that the as prepared hip prosthesis could precisely matched the corresponding parts, which also exhibited good biocompatibility and impressive antibacterial activities. Results: 1) Two inherent technical problems (fragile and sintering induced irregular shrinkage) of 3D printed ceramics were effectively minimized by optimizing the reaction conditions and selective area inversing compensation. 2) It could be seen that the surface of the ZrO2 material was covered with a layer of ZnO nano-particles. A universal testing machine was used to measure the tensile, bending and compression experiments of ceramic samples. It could be found that the proposed ZnO modification had no significant effect on the mechanical properties of ZrO2 ceramics. 3) According to the plate counting results, ceramics modified with ZnO exhibited significantly higher antibacterial efficiency than pure ZrO2 ceramics, the ZrO2-ZnO ceramics had a significant killing effect 8 hours. 4) The removed implants and the tissue surrounding the implant were subjected to HE staining. For ZrO2-ZnO ceramics, inflammation was slight, while for pure ZrO2 ceramics, the inflammatory response could be seen that the antibacterial rate of the ZrO2-ZnO ceramics was significantly better than that of the pure ZrO2 ceramics group. 5) It could be seen that the cytotoxicity did not increase proportionally with the increase of concentration, all of viability were still above 80%. This suggested that our materials were safe and could be applied as a type of potential biomaterial in the future. 6) Further animal studies demonstrated that the implant was in good position without dislocation. This resulted implied that the proposed method can achieve accurate 3D printing preparation of ceramic joints. In addition, the femurs and surrounding muscles around the implant were then sectioned and HE stained. Results of muscle tissue sections further showed no significant tissue abnormalities, and the growth of new bone tissue was observed in the sections of bone tissue. Conclusion: 1) The ceramic 3D printing technology combined with antibacterial nano-modification can quickly customize the ideal implant material with precise structure, wear-resistant and effective antibacterial properties. 2) Two inherent technical problems (fragile and sintering induced irregular shrinkage) of 3D printed ceramics were effectively minimized by optimizing the reaction conditions and selective area inversing compensation. 3) ZnO nano-materials were modified on the ceramic surface, which could effectively killing pathogenic bacteria.


Assuntos
Antibacterianos/farmacologia , Cerâmica/farmacologia , Articulação do Quadril/fisiologia , Impressão Tridimensional , Zircônio/farmacologia , Animais , Articulação do Quadril/efeitos dos fármacos , Masculino , Teste de Materiais , Testes de Sensibilidade Microbiana , Imagem Óptica , Coelhos , Ratos Sprague-Dawley , Staphylococcus aureus/efeitos dos fármacos
19.
J Agric Food Chem ; 67(41): 11508-11517, 2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31538478

RESUMO

Tiopronin, as a novel thiol-containing nucleophile, was introduced for depolymerizing polymeric proanthocyanidins from grape seed into catechins and three new proanthocyanidin-tiopronin degradation products: (+)-catechin-4ß-S-tiopronin methyl ester (CT), (-)-epicatechin-4ß-S-tiopronin methyl ester (ECT), and (-)-epicatechin gallate-4ß-S-tiopronin methyl ester (ECGT). A Box-Behnken design was employed to optimize degradation conditions based on single-factor experiments to obtain target products. Each of the new degradation compounds was isolated by the high-speed counter-current chromatography combined with semipreparative high performance liquid chromatography in large amounts, and then, their structures were identified by 1H NMR, 13C NMR, 2D-NMR, as well as mass spectrometry analysis. The absolute configurations were further confirmed by comparison between the calculated electronic circular dichroism and experimental spectra. Further evaluation of antibacterial activities of these compounds showed that CT and ECT possessed more inhibiting capacity against Staphylococcus aureus and Escherichia coli than parent compound catechin and epicatechin. However, ECGT has no bacteriostatic capacity against these two bacteria.


Assuntos
Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Catequina/química , Distribuição Contracorrente/métodos , Extrato de Sementes de Uva/isolamento & purificação , Extrato de Sementes de Uva/farmacologia , Proantocianidinas/isolamento & purificação , Proantocianidinas/farmacologia , Tiopronina/química , Antibacterianos/química , Cromatografia Líquida de Alta Pressão , Escherichia coli/efeitos dos fármacos , Extrato de Sementes de Uva/química , Proantocianidinas/química , Sementes/química , Espectrometria de Massas por Ionização por Electrospray , Staphylococcus aureus/efeitos dos fármacos , Vitis/química
20.
Photochem Photobiol Sci ; 18(11): 2707-2716, 2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31556891

RESUMO

In this study, the optimal parameters for the photodynamic inactivation (PDI) of Staphylococcus aureus in bacterial suspensions and in cheese were assessed using a water-soluble curcumin salt as the photosensitizer (PS). The in vitro study aimed at finding the optimal concentration and light dose to promote S. aureus photokilling. Four main groups were proposed: CONTROL (L-C-), LIGHT (L+C-), CUR (L-C+) and PDI (L+C+). A fixed light dose (LED, 450 ± 10 nm, 10 J cm-2) was applied using four different PS concentrations (0.75, 1.0, 1.5 and 3.0 mg mL-1). The dose also varied from 10-100 J cm-2 for a fixed concentration. High inactivation rates were observed for all light doses, with a maximum reduction of 7.58 log10 at 100 J cm-2 (p ≪ 0.05). Saturation of the PDI effect was observed after a 10 minute illumination time, as well as a slight decrease in the S. aureus population for increasing illumination times in the L+C- group. As an application, the concentration showing the best decontamination performance in vitro (0.75 mg mL-1) was applied to decontaminate cheese in loco. PDI in two types of coalho cheese, a rennet-coagulated cheese commonly consumed in Brazil, was investigated. The results showed no significant inactivation in unpasteurized cheese, but a 4.34 log10 reduction for t > 5 min in pasteurized specimens. In conclusion, the present PDI-catalyzed curcumin photosensitizer inactivated S. aureus at statistically significant levels in vitro, in pasteurized cheese, but not in unpasteurized specimens.


Assuntos
Queijo/microbiologia , Curcumina/farmacologia , Contaminação de Alimentos/prevenção & controle , Fármacos Fotossensibilizantes/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Luz
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