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1.
World J Microbiol Biotechnol ; 38(1): 18, 2022 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-34977979

RESUMO

Lantibiotics are a promising class of natural antimicrobial peptides. Lichenicidin is a two-peptide lantibiotic in which two mature peptides act synergistically to exhibit full bioactivity. Considering the two-peptide lantibiotics described so far, only cytolysin has been deeply characterized in terms of toxicity towards eukaryotic cells and it was found to be hemolytic and cytotoxic. This work aimed to improve the production of lichenicidin in vivo and characterize its antibacterial activity and toxicity against human cells. Peptides were purified and minimal inhibitory concentration (MIC) was determined against several strains; a time-kill assay was performed with Staphylococcus aureus. The hemolytic effect of lichenicidin was evaluated on blood samples from healthy donors and its toxicity towards human fibroblasts. The quantity of purified peptides was 1 mg/l Bliα and 0.4 mg/l Bliß. MIC for methicillin-sensitive and resistant S. aureus (MSSA and MRSA) strains were 16-32 µg/ml and 64-128 µg/ml, respectively. At the MIC, lichenicidin took less than 3 h to eliminate MSSA, indicating a strong bactericidal effect. It induces cell lysis at the highest concentration, an effect that might be potentiated by Bliß. Lichenicidin was not cytotoxic to human erythrocytes and fibroblasts. In this work, we evaluated the therapeutic potential of lichenicidin as a possible antimicrobial alternative.


Assuntos
Anti-Infecciosos/farmacologia , Bactérias/efeitos dos fármacos , Infecções Bacterianas/tratamento farmacológico , Bacteriocinas/farmacologia , Fibroblastos/efeitos dos fármacos , Peptídeos/farmacologia , Sequência de Aminoácidos , Anti-Infecciosos/química , Anti-Infecciosos/isolamento & purificação , Bacteriocinas/química , Bacteriocinas/isolamento & purificação , Linhagem Celular , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Hemólise , Humanos , Testes de Sensibilidade Microbiana
2.
Arch Microbiol ; 204(1): 119, 2022 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-34989872

RESUMO

The aim of this study was to investigate antimicrobial and antioxidant activities of different fractions obtained from edible Tunisian Ziziphus Lotus leaves of Tozeur region. Different organic extracts were tested: cyclohexane, dichloromethane, ethyl acetate, n-butanol and water. Bio-guided fractionation revealed that dichloromethane fraction is the most active against S. aureus and Methicillin-resistant S. aureus strains. Moreover, this fraction showed the highest antileishmanial activity with IC50 values of 20.55 ± 0.34 µg/mL and 15.37 ± 0.17 µg/mL against L. major and L. infantum, respectively. The potentialities of antibacterial and leishmanicidal activities found in dichloromethane could be explained by the presence of major flavonoids such as catechin, rutin and luteolin 7-O-glucoside as revealed by HPLC system. The observed moderate antifungal activity, which was only given by butanolic fraction against pathogen fungi, may be attributed to the presence of chlorogenic acid. Furthermore, dichloromethane and butanolic fraction showed a good DPPH (2,2-diphenyl-1-picryl hydrazyl) scavenging activity and Ferric reducing power. These results suggest that Ziziphus lotus leaf fractions might be used as antioxidant and antimicrobialagent.


Assuntos
Anti-Infecciosos , Staphylococcus aureus Resistente à Meticilina , Ziziphus , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia , Testes de Sensibilidade Microbiana , Extratos Vegetais/farmacologia , Folhas de Planta , Staphylococcus aureus
3.
J Colloid Interface Sci ; 608(Pt 1): 749-757, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34634547

RESUMO

Cuprous oxide (Cu2O) and cupric oxide (CuO) are widely available and low cost raw materials. Their applications as precursors for wet chemical synthesis of metallic Cu materials are greatly limited due to their insoluble in water and most organic solvents. In this work, copper superfine particles (Cu SPs) are synthesized using Cu2O and CuO as precursors via a heating process in monoethanoamine (MEA). Due to the strong coordinating character, Cu2O and CuO can be partially dissolved in MEA. The dissolved copper source is reduced by MEA at elevated temperature with the drastically releasing of NH3. As the dissolved copper source is reduced, more oxide will be dissolved and finally leads to the full reduction of Cu2O and CuO to produce the Cu SPs. The advantage of this synthesis method is that MEA acts as both the solvent and the reducing agent. The antimicrobial properties are investigated to find that the obtained Cu SPs depress the growth of Escherichia coli (E. coli) and Staphylococcus aureus (St. aureus) efficiently. More interesting, the composites produced via curing Cu2O and CuO with a small amount of MEA also exhibit excellent antimicrobial activity, indicating the MEA curing method is high-efficiency. The synthesis is low cost, high-efficiency, high atom-economy and up-scale synthesizing easily, which will benefit the wide applications of Cu SPs.


Assuntos
Anti-Infecciosos , Cobre , Anti-Infecciosos/farmacologia , Cobre/farmacologia , Escherichia coli , Etanolamina , Óxidos
4.
Colloids Surf B Biointerfaces ; 209(Pt 1): 112172, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34715596

RESUMO

In this work, biocompatible, antimicrobial, and antiviral nanocomposites were prepared through two steps. In the first step, periodate oxidation of cellulose was performed to get dialdehyde cellulose (DAC). The second step included the reaction of DAC with sulfur-containing amino acids included Cysteine (Cys) and Methionine (Meth) in the presence of graphene oxide (GO). The prepared nanocomposites were characterized via FT-IR, SEM, TEM, and TGA. Antimicrobial and antiviral activities for all designed nanocomposites besides DAC were carried out. Both DAC/GO/Cys and DAC/GO/Meth exhibited a promising antimicrobial activity against Gram-negative (E. coli and P. aeruginosa), Gram-positive (B. subtilis and S. aureus), and unicellular fungi (C. Albicans and C. neoformans), while the DAC/GO/Cys/Meth nanocomposite was the lowest. Moreover, all designed nanocomposites have a strong antiviral activity against Herpes simplex virus 1(HSV-1) at minimum nontoxic concentration. Additionally, Computational procedures and Molecular docking showed the reactivity and stability of the molecules that have biological activity against Gram-positive, Gram-negative, and HSV-1. As well as DAC incorporation with amino acid enhanced their reactivity and their interaction.


Assuntos
Anti-Infecciosos , Grafite , Nanocompostos , Aminoácidos , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Antivirais/farmacologia , Celulose , Escherichia coli , Simulação de Acoplamento Molecular , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus aureus
5.
Arch Oral Biol ; 133: 105304, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34775269

RESUMO

OBJECTIVE: To determine the activity of alpha-mangostin on preformed bacterial-fungal multi-species biofilms in vitro, and to ascertain the impact on metabolic activity, biofilm structure and viability. DESIGN: Inhibitory concentrations (ICs) for alpha-mangostin against planktonic cultures of Candida albicans, Enterococcus faecalis, Lactobacillus rhamnosus, and Streptococcus gordonii were determined using a standard broth microdilution method. Single and multi-species (all species 1:1:1:1) biofilms were grown on polystyrene coverslips in Roswell Park Memorial Institute Medium for 48 h. The biofilms were then exposed to 0.2% (w/v) alpha-mangostin for 24 h. These concentrations were selected based on pilot experiments and the solubility of these compounds. 2% (v/v) chlorhexidine was used as a positive control and Roswell Park Memorial Institute Medium as a negative control. The metabolic activity of the biofilms after exposure was measured using metabolic (XTT) assays. Biofilms were visualised and quantified using fluorescent BacLight™ LIVE/DEAD staining. The biofilms were assessed for cell viability by culture and colony counting (CFU/mL). RESULTS: 8 mg/L of alpha-mangostin was cidal against planktonic bacteria and 1000 mg/L for Candida. Alpha-mangostin was most active against L. rhamonosus biofilms and least active against C. albicans biofilm (metabolism inhibited by 99% and 78%, respectively). Alpha-mangostin exposure reduced the number of viable cells in the biofilms. CONCLUSION: Alpha-mangostin inhibited the metabolic activity of bacterial-fungal biofilms effectively. The anti-biofilm activity of alpha-mangostin was comparable to chlorhexidine and thus has potential as a novel agent for endodontic therapy.


Assuntos
Anti-Infecciosos , Xantonas , Anti-Infecciosos/farmacologia , Biofilmes , Enterococcus faecalis , Xantonas/farmacologia
6.
Food Microbiol ; 102: 103869, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34809926

RESUMO

We investigated the synergistic antimicrobial activity of erythorbyl laurate (EL) and mild heating co-treatment on the Gram-positive Listeria innocua and Gram-negative Escherichia coli O157:H7 bacteria. EL (2 mM) and mild heating (55 °C for 3 min) resulted in 3.1 and 0.5 log colony forming units (CFU)/mL reductions in the number of L. innocua, respectively, compared to a 6.4 log CFU/mL reduction induced by the combined treatment of EL and mild heating in saline. EL (10 mM) and mild heating (55 °C for 3 min) resulted in 1.3 and 0.7 log CFU/mL reductions in the number of E. coli O157:H7, respectively, compared to a 6.2 log CFU/mL reduction with the combined treatment in saline. EL, a membrane-active compound, showed a strong synergistic effect with mild heating, possibly due to enhanced disruption of the bacterial cell membrane. The synergistic antibacterial effect was evaluated using inoculated English peas (Pisum sativum) and this combined treatment (2 mM EL and mild heating against L. innocua and 10 mM EL and mild heating against E. coli O157:H7) resulted in more than 7 log reductions in the numbers of L. innocua and E. coli O157:H7, inoculated on the surface of fresh peas. The treatments did not show significant difference in the color or texture of treated peas compared to the non-treated controls. This is the first report illustrating synergistic activity of EL and mild heating for both the gram positive (L. innocua) and the gram negative (E. coli O157:H7) bacteria on food. Overall, this research will illustrate the development of more effective and rapid antibacterial surface disinfection method for application in the processing of minimally processed foods.


Assuntos
Anti-Infecciosos , Escherichia coli O157 , Manipulação de Alimentos , Lauratos/farmacologia , Listeria , Ervilhas/microbiologia , Anti-Infecciosos/farmacologia , Contagem de Colônia Microbiana , Descontaminação , Microbiologia de Alimentos , Temperatura Alta
7.
Food Microbiol ; 102: 103925, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34809951

RESUMO

Antibacterial activity against Escherichia coli O157:H7 and Staphylococcus aureus of five typical plant-derived compounds [gallic acid (G.A), citral (Cit), thymol (Thy), salicylic acid (S.A), lauric acid (L.A)] were investigated by determining the minimum inhibitory concentration (MIC) and the fractional inhibitory concentration index (FICI). The results showed that only a combination of Thy and G.A (TGA), with a concentration of 0.1 and 1.25 mg/mL, respectively, had a synergistic effect (FICI = 0.5) on both E. coli O157:H7 and S. aureus. The amount of Thy and G.A in mixture were four-fold lower than the MICs of the individuals shown to cause the equivalent antimicrobial activity in trypticase soy broth (TSB). The microbial reduction obtained in TSB with addition of TGA were significantly higher (P < 0.05) than the reduction shown for the broth supplemented with the separated phenolics. TGA caused the changes of morphology and membrane integrity of bacteria. Additionally, the application of TGA on fresh-cut tomatoes are investigated. Fresh-cut tomatoes inoculated with E. coli O157:H7and S. aureus were washed for 2min, 5min, 10min at 4 °C, 25 °C, 40 °C in 0.3% NaOCl, or water containing TGA at various concentrations. Overall, the reduction of TGA achieved against S. aureus is higher than E. coli O157:H7. Same concentrations of combined antimicrobials at a temperature of 40 °C further increased the degree of microbial inactivation, with an additional 0.89-1.51 log CFU/g reduction compared to that at 25 °C. Moreover, 1/2MICThy+1/2MICG.A at 25 °C for 10min or 40 °C for 5min were generally acceptable with sensorial scores higher than 7. Our results showed that TGA could work synergistically on the inactivation of the tested bacteria and may be used as an alternative disinfectant of fresh produce.


Assuntos
Anti-Infecciosos , Escherichia coli O157 , Ácido Gálico , Lycopersicon esculentum , Staphylococcus aureus , Timol , Anti-Infecciosos/farmacologia , Contagem de Colônia Microbiana , Escherichia coli O157/efeitos dos fármacos , Contaminação de Alimentos/prevenção & controle , Microbiologia de Alimentos , Ácido Gálico/farmacologia , Lycopersicon esculentum/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Timol/farmacologia
8.
Food Chem ; 366: 130606, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34311233

RESUMO

A natamycin-based non-migratory antimicrobial packaging for extending shelf-life of yogurt drink (Doogh) was developed. Firstly, the surface of low-density polyethylene film (LDPE) was modified with acrylic acid at different times of UV exposure (0-10 min) to produce carboxylic functional groups. Then, natamycin was applied to the UV-treated films to bind covalently with the pendent functional groups. The maximum grafting efficiency (81.96%) was obtained for the 6 min treated film. Moreover, surface properties of films were evaluated by Attenuated Total Reflectance/Fourier Transfer Infrared Spectroscopy (ATR-FTIR) and scanning electron microscopy (SEM). Antifungal activity of different treatments of natamycin grafted film was evaluated against two common spoilage yeasts of Doogh including Rhodotorula mucilaginosa and Candida parapsilosis. Results showed that 6 min treated film provides maximum anti-yeast activity and can be applied to control fungal growth in Doogh. Natamycin-grafted film postponed the yeast spoilage in Doogh and prolonged its shelf-life to 23 days.


Assuntos
Anti-Infecciosos , Natamicina , Anti-Infecciosos/farmacologia , Embalagem de Alimentos , Rhodotorula , Iogurte
9.
Colloids Surf B Biointerfaces ; 209(Pt 2): 112186, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34740094

RESUMO

Essential oils (EOs) are complex natural mixtures of secondary plant metabolites that function as biocides and therapeutic agents. They are extensively used in bactericidal, virucidal, fungicidal, antiparasitic, insecticidal, pharmaceutical, and cosmetic products. However, certain characteristics, such as the volatility of EOs, hinder their widespread use. To mitigate this limitation, several studies have investigated combinations of EOs with natural materials, including clay minerals. Clay minerals are abundant in nature, biocompatible, and non-toxic to the environment and humans. Clay minerals such as montmorillonite possess available sites where EO molecules can interact. The combination of EOs with clay minerals produces new materials for various applications including antibacterial, antifungal, insecticidal/repellent, and active packaging materials. Therefore, this review focuses on the immobilization of several types of EOs in raw and modified montmorillonites. The applications of the described systems were evaluated and demonstrated the synergism of the properties of the isolated components as a function of different EOs incorporated in the silicate matrix.


Assuntos
Anti-Infecciosos , Repelentes de Insetos , Inseticidas , Óleos Voláteis , Anti-Infecciosos/farmacologia , Bentonita , Humanos , Inseticidas/farmacologia , Óleos Voláteis/farmacologia
10.
Cardiovasc Pathol ; 56: 107382, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34478860

RESUMO

BACKGROUND: Histopathologic differentiation of bacterial endocarditis from yeast-like fungal endocarditis is usually straightforward; however, an underappreciated phenomenon is the effect of antimicrobial therapy on bacterial size, shape and septa (cross-wall) formation resulting in bacterial forms that mimic yeast-like fungi. In this article we illustrate the alterations that occur in antibiotic-treated Staphylococcus aureus endocarditis and compare these changes to histopathologic findings in unaltered S. aureus and Histoplasma endocarditis, respectively. METHODS: Resected valves from three cases of endocarditis were compared based on the type ofinflammatory reaction, organism morphology and culture results. Case 1 was S. aureus endocarditis initially misclassified as Histoplasma due to its atypical morphologic and histopathologic features. The two cases included for comparison were an S. aureus endocarditis with more classic features and an Histoplasma capsulatum endocarditis. Hematoxylin and eosin (H&E), Gram, periodic acid Schiff (PAS), Gomori-Grocott methenamine silver stains (GMS), and culture results were compared in all cases. Molecular and immunohistochemistry tests were used for confirmation of first case. High power oil-immersion was used to visualize organisms' characteristics in all three cases. RESULTS: Case 1 and Case 3 (Histoplasma-infected valves) had fibrinous exudates with scattered macrophages. The microorganisms observed in the first case of methicillin-sensitive S. aureus (MSSA) were ∼ 2-3 µm by GMS stain and had prominent septations. Histoplasma yeast were round to oval, ∼ 3-4 µm in size and demonstrated budding. S. aureus without alterations were round, ∼ 1 µm in size, and lacked prominent septations. Necrotizing purulent inflammation was present in the unaltered case of MSSA. The MSSA case with alterations from antibiotic treatment did not stain well with the Gram stain and organisms were best visualized with the PAS and GMS stains. CONCLUSIONS: Antibiotic therapy for bacterial endocarditis can alter the inflammatory reaction to infection, bacterial size, septa formation, and staining characteristics. Knowledge of these therapy-related effects and use of high-power magnification helps to avoid misclassification as yeast-like fungi.


Assuntos
Endocardite Bacteriana , Endocardite , Fungos , Anti-Infecciosos/farmacologia , Diagnóstico Diferencial , Endocardite/microbiologia , Endocardite/patologia , Endocardite Bacteriana/tratamento farmacológico , Endocardite Bacteriana/patologia , Humanos , Staphylococcus aureus/efeitos dos fármacos
11.
Nanoscale ; 14(2): 239-249, 2022 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-34935015

RESUMO

Infectious diseases caused by viral or bacterial pathogens are one of the most serious threats to humanity. Moreover, they may lead to pandemics, as we have witnessed severely with the coronavirus disease 2019 (COVID-19). Nanotechnology, including technological developments of nano-sized materials, has brought great opportunities to control the spreading of such diseases. In the family of nano-sized materials, two-dimensional (2D) materials with intrinsic physicochemical properties can efficiently favor antimicrobial activity and maintain a safer environment to protect people against pathogens. For this purpose, they can be used alone or combined for the disinfection process of microbes, antiviral or antibacterial surface coatings, air filtering of medical equipment like face masks, or antimicrobial drug delivery systems. At the same time, they are promising candidates to deal with the issues of conventional antimicrobial approaches such as low efficacy and high cost. This review covers the antiviral or antibacterial activities of 2D materials and highlights their current and possible future applications. Considering their intrinsic properties, 2D materials will become part of the leading antimicrobial technologies for combating future pandemics anytime soon.


Assuntos
Anti-Infecciosos , COVID-19 , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Humanos , Pandemias , SARS-CoV-2
12.
Methods Mol Biol ; 2343: 215-228, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34473325

RESUMO

The Bouea macrophylla (B. macrophylla) tree is widely grown throughout South East Asia and has been used as a traditional medicine for the treatment of various illnesses. This chapter presents a protocol for preparation of ethanol extracts of B. macrophylla leaves and evaluation of the potential antimicrobial and anticancer activities in vitro. The extract displayed antibacterial activity against nine out of the ten target microorganisms tested. In addition, the extract was capable of inhibiting the proliferation of HeLa and HCT116 cells, thus demonstrating some anticancer activity.


Assuntos
Anacardiaceae , Anti-Infecciosos , Antineoplásicos , Extratos Vegetais , Anacardiaceae/química , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Antineoplásicos/farmacologia , Etanol , Humanos , Extratos Vegetais/farmacologia , Folhas de Planta
13.
Chemosphere ; 287(Pt 4): 132276, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34601372

RESUMO

Phytoconstituents of plants had enormous therapeutic potential against the wounds on skin. Plants like Tecoma stans, Manilkara zapota and Cassia fistula were some which had the ability to heal the wounds. However, there was limited research in Cassia fistula flowers and its synergism with plants on wound healing and its mechanism. Qualitative analysis was performed to confirm the presence of phytoconstituents like flavonoids, saponins and tannins in solvents:aqueous ethanol and methanol. All three components showed their attributes towards wound healing. Results of antimicrobial activity clearly stated that, methanol extract of the Cassia fistula flowers at increasing concentration, showed the maximum zone of inhibition of 27 mm at 100 µl (antibacterial assay) and 18 mm at 100 µl (anti-fungal assay). They had higher potential against the selective microbes Staphylococcus aureus and Aspergillus niger. The combination of C. fistula flowers and C. fistula leaves; C. fistula flowers and M. zapota leaves showed maximum zone of inhibition of 23 mm and 21 mm for anti-bacterial; 22 mm and 23 mm for antifungal at 100 µl respectively. The C. fistula flowers along with the Manilkara zapota leaves and C. fistula leaves enhanced the antimicrobial nature than the individual plants. The antimicrobial properties present in the plants would engage them in future for developing an improved medicine for wound healing. Thus a polyherbal plant solution containing equal proportions of plants, tested for the antibacterial activity, succeeded by showing its higher inhibition of 25 mm at 100 µl.This concluded that the synergism of plants had higher efficiency in microbial activity than the individual samples hence proving the plants attributes towards the wound healing.


Assuntos
Anti-Infecciosos , Bignoniaceae , Plantas Medicinais , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Testes de Sensibilidade Microbiana , Extratos Vegetais/farmacologia , Folhas de Planta
14.
Methods Mol Biol ; 2383: 335-345, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34766300

RESUMO

In the last decades, the increasing rate of multidrug-resistant bacteria to classical antibiotics has driven research towards identification of other means to fight bacterial infections. In this context, intracellular and/or invasive facultative intracellular bacteria represent a particular problem as common antimicrobials are often not able to reach an effective intracellular concentration. In this regard, cell-penetrating peptides (CPP) can mediate the internalization of previously nonpermeable antimicrobial compounds into the cytoplasm of host cells where they efficiently kill intracellular pathogens. This chapter describes the conjugation of CPPs with antimicrobial agents for the delivery into infected cells. Furthermore, different antimicrobial activity assays will be described including the CPP-mediated delivery of an antimicrobial agent for the treatment of intracellular infections.


Assuntos
Anti-Infecciosos/farmacologia , Infecções Bacterianas , Antibacterianos/farmacologia , Infecções Bacterianas/tratamento farmacológico , Peptídeos Penetradores de Células , Farmacorresistência Bacteriana Múltipla , Humanos
15.
Food Microbiol ; 101: 103876, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34579844

RESUMO

The efficacy of plant-based antimicrobials against Salmonella Newport and Listeria monocytogenes on melon rinds was evaluated. Four cantaloupe and 3 honeydew melon varieties grown in Georgia, Arizona, Texas, North Carolina, Indiana and California were tested. Melon rinds (10 g pieces) were inoculated with 5-6 log CFU/10 g rind of S. Newport or L. monocytogenes. Samples were then immersed in 5 % olive extract or 0.5 % oregano oil antimicrobial solution and gently agitated for 2 min. Samples were stored at 4 °C and surviving populations of both bacteria were enumerated at days 0 and 3. Plant-based antimicrobials reduced S. Newport and L.monocytogenes population on all rind samples, regardless of the melon types, varieties or growing locations. Compared to the control, antimicrobial treatments caused up to 3.6 and 4.0 log reductions in populations of Salmonella and L. monocytogenes, respectively. In most cases, plant-based antimicrobial treatments reduced pathogen populations to below the detection limit (1 log CFU/g) at day 3. In general, oregano oil had better antimicrobial activity than olive extract and the antimicrobial treatments were more effective on Salmonella than on L. monocytogenes. The plant-based antimicrobial treatments exhibited better microbial reductions on honeydews than on cantaloupes. These antimicrobials could potentially be used as sanitizers for decontaminating melons.


Assuntos
Anti-Infecciosos , Cucurbitaceae , Contaminação de Alimentos/prevenção & controle , Listeria monocytogenes , Salmonella enterica , Anti-Infecciosos/farmacologia , Contagem de Colônia Microbiana , Qualidade de Produtos para o Consumidor , Cucurbitaceae/microbiologia , Manipulação de Alimentos , Microbiologia de Alimentos , Listeria monocytogenes/efeitos dos fármacos , Salmonella enterica/efeitos dos fármacos , Estados Unidos
16.
Food Chem ; 368: 130831, 2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-34403999

RESUMO

This research aimed to apply nanotechnology for nanoformulation of Laurus nobilis essential oil (EO) by ultrasonic emulsification method and characterization of nano-form: particle size, viscosity, polydispersity index, thermodynamic stability, and surface tension. The antimicrobial activity of laurel EO nanoemulsion (LEON) and laurel EO was also investigated against a panel of ten food-borne pathogens and fish spoilage bacteria. The GC-MS analysis of EO revealed that 1,8-Cineole was the main volatile compound. According to disc-diffusion results, LEON was more effective against Gram-positive pathogen bacteria of Staphylococcus aureus and Enterococcus faecalis than EO. Laurel oil demonstrated a higher inhibitory effect against fish spoilage bacteria (6.19 to 18.5 mm). The MICs values of LEON and laurel EO ranged from 6.25 to >25 mg/mL and from 1.56 to >25 mg/mL, respectively. Nanoemulsion and oil exhibited the best bactericidal activity against Pseudomonas luteola. Therefore, LEON can be developed as a natural antimicrobial agent in food industry.


Assuntos
Anti-Infecciosos , Óleos Voláteis , Anti-Infecciosos/farmacologia , Bactérias , Testes de Sensibilidade Microbiana , Óleos Voláteis/farmacologia , Pseudomonas , Sesquiterpenos
17.
Food Chem ; 368: 130784, 2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-34411864

RESUMO

Biodegradable and antimicrobial films without antibiotics are of great significance for the application associated with food packaging meanwhile minimizing the negative impact on environments. In this work, cellulose-based films with the surface tailor-constructed with ZnO nanopillars (ZnO NPs@Zn2+/Cel films) were prepared via chemical crosslinking in conjunction with a hydrothermal process for in-situ growth of ZnO NPs. As a packaging material, ZnO NPs@Zn2+/Cel films possess excellent mechanical properties, oxygen and water vapor barrier, food preservation, biodegradability and low Zn2+ migration. Moreover, ZnO NPs@Zn2+/Cel films show remarkable antimicrobial activity, especially for Staphylococcus aureus (gram-positive bacteria) and Escherichia coli (gram-negative bacteria). The antimicrobial mechanism of ZnO NPs@Zn2+/Cel films is studied using the controlled variable method, and results showed that the film without UV pretreatment killed bacterial cells mainly by mechanical rupture, while the film with UV pretreatment killed bacterial cells mainly via the synergistic effect of photocatalytic oxidation and mechanical rupture.


Assuntos
Anti-Infecciosos , Nanocompostos , Óxido de Zinco , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Celulose , Embalagem de Alimentos , Óxido de Zinco/farmacologia
18.
Spectrochim Acta A Mol Biomol Spectrosc ; 264: 120273, 2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-34425316

RESUMO

Amphibians are a natural source of a large number of peptides with a wide range of functional activities. Here, a complex of spectroscopic methods including NMR-, FTIR-, CD-, and UV-spectroscopy was applied to characterize the structure and functional activity of megin-1, a peptide isolated from amphibian skin. The three-dimensional structure of two forms of the peptide was determined using solution NMR spectroscopy. Thermodynamic characteristics of the process of peptide transformation from linear to cyclic form were obtained. Antibacterial and antimycotic properties of the peptide, as well as its protease inhibitory activities, were analyzed.


Assuntos
Anti-Infecciosos , Peptídeos Catiônicos Antimicrobianos , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Espectroscopia de Ressonância Magnética , Proteínas Citotóxicas Formadoras de Poros
19.
J Sci Food Agric ; 102(1): 19-40, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34453323

RESUMO

Eleocharis dulcis, an aquatic plant belonging to Cyperaceae family, is indigenous to Asia, and also occurs in tropical Africa and Australia. The edible corm part of E. dulcis is a commonly consumed aquatic vegetable with a planting area of 44.46 × 103 hm2 in China. This work aims to explore the potential of E. dulcis corm for use as a new food source for sufficient nutrients and health benefits by reviewing its nutrients, phytochemicals, functions, processing and food products. Eleocharis dulcis corm contains starches, dietary fibers, non-starch polysaccharides, proteins, amino acids, phenolics, sterols, puchiin, saponins, minerals and vitamins. Among them, phenolics including flavonoids and quinones could be the major bioconstituents that largely contribute to antioxidant, anti-inflammatory, antibacterial, antitumor, hepatoprotective, neuroprotective and hypolipidemic functions. Peel wastes of E. dulcis corm tend to be enriched in phenolics to a much higher extent than the edible pulp. Fresh-cut E. dulcis corm can be consumed as a ready-to-eat food or processed into juice for beverage production, and anti-browning processing is a key to prolonging shelf life. Present food products of E. dulcis corm are centered on various fruit and vegetable beverages, and suffer from single categories and inadequate development. In brief, underutilized E. dulcis corm possesses great potential for use as a new food source for sufficient nutrients and health benefits. © 2021 Society of Chemical Industry.


Assuntos
Eleocharis/química , Compostos Fitoquímicos/química , Animais , Anti-Infecciosos/química , Anti-Infecciosos/metabolismo , Anti-Infecciosos/farmacologia , Anti-Inflamatórios/química , Anti-Inflamatórios/metabolismo , Anti-Inflamatórios/farmacologia , Antioxidantes/química , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Eleocharis/metabolismo , Manipulação de Alimentos , Humanos , Compostos Fitoquímicos/metabolismo , Compostos Fitoquímicos/farmacologia , Caules de Planta/química , Caules de Planta/metabolismo
20.
Food Chem ; 366: 130608, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34454799

RESUMO

Hydrochar of waste walnut shells (WSH) was synthesized in the eco-friendly subcritical water medium (SWM) and its potential to fight against Klebsiella pneumoniae (K. pneumoniae), Staphylococcus aureus (S. aureus), Candida albicans (C. albicans) and Candida parapsilosis (C. parapsilosis) was investigated. Minimum Inhibitory Concentration (MIC) values of the WSH were 3.01 g/mL, 2.06 g/mL, 1.95 g/mL, and 3.12 g/mL for K. pneumoniae, S. aureus, C. albicans and C. parapsilosis, respectively. Survival of the pathogens was investigated by 3 min surface disinfection test exposure to WSH. While the highest inhibition was seen for C. parapsilosis (96.67%) on paper surface with 0.3 g/mL of bovine serum albumin (BSA), the lowest inhibition was determined for C. albicans (6.44%) on the plastic glass surface with 3 g/mL of BSA. An increase in protein, DNA, and potassium ion (K+) leakage was observed after microorganisms were incubated with WSH. This study provided an experimental basis for the practical application of WSH as a natural sanitizer agent.


Assuntos
Anti-Infecciosos , Juglans , Anti-Infecciosos/farmacologia , Candida albicans , Testes de Sensibilidade Microbiana , Staphylococcus aureus
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