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1.
Nat Commun ; 12(1): 2321, 2021 04 19.
Artículo en Inglés | MEDLINE | ID: mdl-33875652

RESUMEN

Bactericidal antibiotics kill bacteria by perturbing various cellular targets and processes. Disruption of the primary antibiotic-binding partner induces a cascade of molecular events, leading to overproduction of reactive metabolic by-products. It remains unclear, however, how these molecular events contribute to bacterial cell death. Here, we take a single-cell physical biology approach to probe antibiotic function. We show that aminoglycosides and fluoroquinolones induce cytoplasmic condensation through membrane damage and subsequent outflow of cytoplasmic contents as part of their lethality. A quantitative model of membrane damage and cytoplasmic leakage indicates that a small number of nanometer-scale membrane defects in a single bacterium can give rise to the cellular-scale phenotype of cytoplasmic condensation. Furthermore, cytoplasmic condensation is associated with the accumulation of reactive metabolic by-products and lipid peroxidation, and pretreatment of cells with the antioxidant glutathione attenuates cytoplasmic condensation and cell death. Our work expands our understanding of the downstream molecular events that are associated with antibiotic lethality, revealing cytoplasmic condensation as a phenotypic feature of antibiotic-induced bacterial cell death.


Asunto(s)
Antibacterianos/farmacología , Membrana Celular/efectos de los fármacos , Citoplasma/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Aminoglicósidos/farmacología , Permeabilidad de la Membrana Celular/efectos de los fármacos , Citoplasma/metabolismo , Escherichia coli/citología , Escherichia coli/metabolismo , Fluoroquinolonas/farmacología , Pruebas de Sensibilidad Microbiana/métodos , Viabilidad Microbiana/efectos de los fármacos , Microscopía de Fuerza Atómica/métodos , Microscopía Fluorescente/métodos , Análisis de la Célula Individual/métodos
2.
Molecules ; 26(4)2021 Feb 18.
Artículo en Inglés | MEDLINE | ID: mdl-33670455

RESUMEN

Many studies suggest anthocyanins may prevent the development of several diseases. However, anthocyanin bioactivity against cellular stress is not fully understood. This study aimed to evaluate the protective effect of berry anthocyanins on stressed cells using Saccharomyces cerevisiae. The impact of in vitro gastrointestinal digestion on anthocyanin profiles was also assessed. Bilberry and blackcurrant had higher anthocyanin levels than raspberry and strawberry, but digestion reduced the detected anthocyanins by approximately 90%. Yeast cells with and without digested or nondigested anthocyanin extracts were exposed to H2O2 and examined for survival. In the presence of anthocyanins, particularly from digested strawberry, a significant increase in cell survival was observed, suggesting that the type and levels of anthocyanins are important factors, but they also need to undergo gastrointestinal (GI) structural modifications to induce cell defence. Results also showed that cells need to be exposed to anthocyanins before the stress was applied, suggesting induction of a cellular defence system by anthocyanins or their derivatives rather than by a direct antioxidative effect on H2O2. Overall, data showed that exposure of severely stressed yeast cells to digested berry extracts improved cell survival. The findings also showed the importance of considering gastrointestinal digestion when evaluating anthocyanins' biological activity.


Asunto(s)
Frutas/química , Peróxido de Hidrógeno/toxicidad , Viabilidad Microbiana/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Extractos Vegetales/farmacología , Saccharomyces cerevisiae/citología , Antocianinas/análisis , Antocianinas/química , Sustancias Protectoras/farmacología , Saccharomyces cerevisiae/efectos de los fármacos , Saccharomyces cerevisiae/crecimiento & desarrollo
3.
Molecules ; 26(4)2021 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-33672903

RESUMEN

Burkholderia pseudomallei is the causative pathogen of melioidosis and this bacterium is resistant to several antibiotics. Silver nanoparticles (AgNPs) are an interesting agent to develop to solve this bacterial resistance. Here, we characterize and assess the antimelioidosis activity of AgNPs against these pathogenic bacteria. AgNPs were characterized and displayed a maximum absorption band at 420 nm with a spherical shape, being well-monodispersed and having high stability in solution. The average size of AgNPs is 7.99 ± 1.46 nm. The antibacterial efficacy of AgNPs was evaluated by broth microdilution. The bactericidal effect of AgNPs was further assessed by time-kill kinetics assay. Moreover, the effect of AgNPs on the inhibition of the established biofilm was investigated by the crystal violet method. In parallel, a study of the resistance induction development of B. pseudomallei towards AgNPs with efflux pump inhibiting effect was performed. We first found that AgNPs had strong antibacterial activity against both susceptible and ceftazidime-resistant (CAZ-resistant) strains, as well as being efficiently active against B. pseudomallei CAZ-resistant strains with a fast-killing mode via a bactericidal effect within 30 min. These AgNPs did not only kill planktonic bacteria in broth conditions, but also in established biofilm. Our findings first documented that the resistance development was not induced in B. pseudomallei toward AgNPs in the 30th passage. We found that AgNPs still showed an effective efflux pump inhibiting effect against these bacteria after prolonged exposure to AgNPs at sublethal concentrations. Thus, AgNPs have valuable properties for being a potent antimicrobial agent to solve the antibiotic resistance problem in pathogens.


Asunto(s)
Proteínas Bacterianas/antagonistas & inhibidores , Burkholderia pseudomallei/fisiología , Melioidosis/tratamiento farmacológico , Melioidosis/microbiología , Nanopartículas del Metal/uso terapéutico , Plata/uso terapéutico , Taninos/uso terapéutico , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Proteínas Bacterianas/metabolismo , Burkholderia pseudomallei/efectos de los fármacos , Ceftazidima/farmacología , Ceftazidima/uso terapéutico , Farmacorresistencia Bacteriana/efectos de los fármacos , Dispersión Dinámica de Luz , Cinética , Nanopartículas del Metal/ultraestructura , Pruebas de Sensibilidad Microbiana , Viabilidad Microbiana/efectos de los fármacos , Fenotipo , Plata/farmacología , Electricidad Estática , Taninos/farmacología
4.
Molecules ; 26(4)2021 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-33672940

RESUMEN

Pseudomonas is considered as the specific spoilage bacteria in meat and meat products. The purpose of this study was to evaluate the inactivation efficiency and mechanisms of slightly acidic electrolyzed water (SAEW) against Pseudomonas deceptionensis CM2, a strain isolated from spoiling chicken breast. SAEW caused time-dependent inactivation of P. deceptionensis CM2 cells. After exposure to SAEW (pH 5.9, oxidation-reduction potential of 945 mV, and 64 mg/L of available chlorine concentration) for 60 s, the bacterial populations were reduced by 5.14 log reduction from the initial load of 10.2 log10 CFU/mL. Morphological changes in P. deceptionensis CM2 cells were clearly observed through field emission-scanning electron microscopy as a consequence of SAEW treatment. SAEW treatment also resulted in significant increases in the extracellular proteins and nucleic acids, and the fluorescence intensities of propidium iodide and n-phenyl-1-napthylamine in P. deceptionensis CM2 cells, suggesting the disruption of cytoplasmic and outer membrane integrity. These findings show that SAEW is a promising antimicrobial agent.


Asunto(s)
Ácidos/farmacología , Membrana Celular/patología , Electrólisis , Viabilidad Microbiana/efectos de los fármacos , Pseudomonas/efectos de los fármacos , Agua/farmacología , Membrana Celular/efectos de los fármacos , Membrana Celular/ultraestructura , Permeabilidad de la Membrana Celular/efectos de los fármacos , Citoplasma/efectos de los fármacos , Desinfección , Pseudomonas/citología , Pseudomonas/ultraestructura
5.
Int J Mol Sci ; 22(4)2021 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-33672733

RESUMEN

Sigma factor C (SigC) contributes to Mycobacterium tuberculosis virulence in various animal models, but the stress response coordinated by this transcription factor was undefined. The results presented here indicate that SigC prevents copper starvation. Whole genome expression studies demonstrate short-term (4-h) induction of sigC, controlled from a tetracycline-inducible promoter, upregulates ctpB and genes in the nonribosomal peptide synthase (nrp) operon. These genes are expressed at higher levels after 48-h sigC induction, but also elevated are genes encoding copper-responsive regulator RicR and RicR-regulated copper toxicity response operon genes rv0846-rv0850, suggesting prolonged sigC induction results in excessive copper uptake. No growth and global transcriptional differences are observed between a sigC null mutant relative to its parent strain in 7H9 medium. In a copper-deficient medium, however, growth of the sigC deletion strain lags the parent, and 40 genes (including those in the nrp operon) are differentially expressed. Copper supplementation reverses the growth defect and silences most transcriptional differences. Together, these data support SigC as a transcriptional regulator of copper acquisition when the metal is scarce. Attenuation of sigC mutants in severe combined immunodeficient mice is consistent with an inability to overcome innate host defenses that sequester copper ions to deprive invading microbes of this essential micronutrient.


Asunto(s)
Cobre/farmacología , Inmunidad/efectos de los fármacos , Mycobacterium tuberculosis/metabolismo , Factor sigma/metabolismo , Animales , Proteínas Bacterianas/metabolismo , Transporte Biológico/efectos de los fármacos , Sulfato de Cobre/farmacología , Femenino , Perfilación de la Expresión Génica , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Ratones SCID , Viabilidad Microbiana/efectos de los fármacos , Mutación/genética , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/crecimiento & desarrollo , Fenotipo , Transcripción Genética/efectos de los fármacos , Virulencia/efectos de los fármacos , Virulencia/genética
6.
Carbohydr Polym ; 260: 117843, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33712117

RESUMEN

In this study, trehalose (TRE) was added to prepare whey protein concentrate (WPC)/pullulan (PUL)/TRE hydrogel and the hydrogel was used as the wall material to improve the viability of encapsulated L. plantarum during freeze drying and storage. The optimum conditions were 5.0 % TRE concentration and 1:4 (v:v) of the ratio of L. plantarum suspension to the hydrogel. Under these conditions, the survival rates of L. plantarum were 94.36 ± 1.06 % after freeze drying and 97.02 ± 0.30 % after storage for 240 d at 4 °C. Interactions and rheological properties of WPC/PUL/TRE hydrogel were also studied. The results showed TRE reduced storage modulus (G') of the hydrogel and weakened hydrophobic interactions, disulfide and hydrogen bonds between proteins and polysaccharides, which was not conducive to hydrogel formation. In addition, the excellent water-holding capacity of WPC/PUL/TRE hydrogel was found by the drying kinetic experiment.


Asunto(s)
Glucanos/química , Hidrogeles/química , Lactobacillus plantarum/fisiología , Trehalosa/química , Proteína de Suero de Leche/química , Liofilización , Hidrogeles/farmacología , Enlace de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Viabilidad Microbiana/efectos de los fármacos , Reología , Compuestos de Sulfhidrilo/química
7.
Carbohydr Polym ; 261: 117859, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33766348

RESUMEN

Development of an effective purification process in order to provide low cost and high-quality vaccine is the necessity of glycoconjugate vaccine manufacturing industries. In the present study, we have attempted to develop a method for simultaneous purification and depolymerization process for capsular polysaccharides (CPS) derived from Streptococcus pneumoniae serotype 2. Trifluoroacetic acid (TFA) was used to precipitate impurities which were then removed by centrifugation. It was observed that the TFA treatment could simultaneously depolymerize the CPS and purify it. The purified and depolymerized CPS was analyzed for its purity, structural identity and conformity, molecular size, antigenicity to meet desired quality specifications. The obtained results showed that the purification and depolymerization of S. pneumoniae serotype 2 CPS did not affect the antigenicity of CPS.


Asunto(s)
Cápsulas Bacterianas/química , Polimerizacion/efectos de los fármacos , Polisacáridos Bacterianos/aislamiento & purificación , Streptococcus pneumoniae/efectos de los fármacos , Ácido Trifluoroacético/farmacología , Cápsulas Bacterianas/efectos de los fármacos , Vacunas Bacterianas/química , Vacunas Bacterianas/inmunología , Inmunogenicidad Vacunal/efectos de los fármacos , Viabilidad Microbiana/efectos de los fármacos , Infecciones Neumocócicas/prevención & control , Polisacáridos Bacterianos/química , Polisacáridos Bacterianos/inmunología , Polisacáridos Bacterianos/metabolismo , Serogrupo , Streptococcus pneumoniae/química , Streptococcus pneumoniae/citología , Streptococcus pneumoniae/inmunología , Vacunas Atenuadas/química , Vacunas Atenuadas/inmunología
8.
Int J Food Microbiol ; 343: 109090, 2021 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-33631606

RESUMEN

Plasma-activated water (PAW) has good liquidity and uniformity and may be a promising candidate to inactivate Penicillium italicum and maintain the quality attributes of kumquat. In this study, the effect of plasma-activated water (PAW) on the viability of Penicillium italicum on kumquat and quality attributes of PAW-treated kumquats were then systematically investigated to elucidate the correlation between PAW and kumquat quality attributes. The effects of PAW on fruit decay, microbial loads, and firmness of postharvest kumquats during the 6-week storage were also investigated. The results showed that the viability of Penicillium italicum was notably inhibited by PAW on kumquats. Moreover, PAW did not significantly change the surface color of kumquats. No significant reductions in ascorbic acid, total flavonoid, and carotenoids were observed in kumquats after the PAW treatment. Results from nitrate and nitrite residue analyses showed that PAW did not leave serious nitrate and nitrite residues after treatment. The decay analysis results demonstrated that PAW has the potential to control kumquat decay and fungal contamination as well as maintain the firmness of postharvest kumquats throughout 6-week storage. Transmit electron microscope observation confirmed that PAW could cause the surface sculpturing in the skin cell wall of kumquat. The information obtained from this research may provide insight into the utilization of PAW to fight against fungal infection during the storage of citrus fruit.


Asunto(s)
Desinfectantes/farmacología , Penicillium/efectos de los fármacos , Gases em Plasma/farmacología , Rutaceae/microbiología , Agua/farmacología , Pared Celular/efectos de los fármacos , Microbiología de Alimentos , Almacenamiento de Alimentos , Frutas/microbiología , Viabilidad Microbiana/efectos de los fármacos , Agua/química
9.
Nat Med ; 27(4): 700-709, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33619370

RESUMEN

Staphylococcus aureus colonizes patients with atopic dermatitis (AD) and exacerbates disease by promoting inflammation. The present study investigated the safety and mechanisms of action of Staphylococcus hominis A9 (ShA9), a bacterium isolated from healthy human skin, as a topical therapy for AD. ShA9 killed S. aureus on the skin of mice and inhibited expression of a toxin from S. aureus (psmα) that promotes inflammation. A first-in-human, phase 1, double-blinded, randomized 1-week trial of topical ShA9 or vehicle on the forearm skin of 54 adults with S. aureus-positive AD (NCT03151148) met its primary endpoint of safety, and participants receiving ShA9 had fewer adverse events associated with AD. Eczema severity was not significantly different when evaluated in all participants treated with ShA9 but a significant decrease in S. aureus and increased ShA9 DNA were seen and met secondary endpoints. Some S. aureus strains on participants were not directly killed by ShA9, but expression of mRNA for psmα was inhibited in all strains. Improvement in local eczema severity was suggested by post-hoc analysis of participants with S. aureus directly killed by ShA9. These observations demonstrate the safety and potential benefits of bacteriotherapy for AD.


Asunto(s)
Dermatitis Atópica/microbiología , Dermatitis Atópica/terapia , Piel/microbiología , Staphylococcus hominis/fisiología , Administración Tópica , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Proteínas Bacterianas/metabolismo , Bacteriocinas/farmacología , Recuento de Colonia Microbiana , Humanos , Inflamación/complicaciones , Inflamación/patología , Ratones Endogámicos BALB C , Pruebas de Sensibilidad Microbiana , Viabilidad Microbiana/efectos de los fármacos , Persona de Mediana Edad , Péptidos Cíclicos/metabolismo , Reproducibilidad de los Resultados , Piel/efectos de los fármacos , Piel/patología , Infecciones Estafilocócicas/microbiología , Infecciones Estafilocócicas/terapia , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/crecimiento & desarrollo , Staphylococcus aureus/fisiología , Transcripción Genética/efectos de los fármacos , Resultado del Tratamiento , Factores de Virulencia/metabolismo , Adulto Joven
10.
J Vis Exp ; (167)2021 01 22.
Artículo en Inglés | MEDLINE | ID: mdl-33554970

RESUMEN

The effective prescription of antibiotics for the bacterial biofilms present within the lungs of individuals with cystic fibrosis (CF) is limited by a poor correlation between antibiotic susceptibility testing (AST) results using standard diagnostic methods (e.g., broth microdilution, disk diffusion, or Etest) and clinical outcomes after antibiotic treatment. Attempts to improve AST by the use of off-the-shelf biofilm growth platforms show little improvement in results. The limited ability of in vitro biofilm systems to mimic the physicochemical environment of the CF lung and, therefore bacterial physiology and biofilm architecture, also acts as a brake on the discovery of novel therapies for CF infection. Here, we present a protocol to perform AST of CF pathogens grown as mature, in vivo-like biofilms in an ex vivo CF lung model comprised of pig bronchiolar tissue and synthetic CF sputum (ex vivo pig lung, EVPL). Several in vitro assays exist for biofilm susceptibility testing, using either standard laboratory medium or various formulations of synthetic CF sputum in microtiter plates. Both growth medium and biofilm substrate (polystyrene plate vs. bronchiolar tissue) are likely to affect biofilm antibiotic tolerance. We show enhanced tolerance of clinical Pseudomonas aeruginosa and Staphylococcus aureus isolates in the ex vivo model; the effects of antibiotic treatment of biofilms is not correlated with the minimum inhibitory concentration (MIC) in standard microdilution assays or a sensitive/resistant classification in disk diffusion assays. The ex vivo platform could be used for bespoke biofilm AST of patient samples and as an enhanced testing platform for potential antibiofilm agents during pharmaceutical research and development. Improving the prescription or acceleration of antibiofilm drug discovery through the use of more in vivo-like testing platforms could drastically improve health outcomes for individuals with CF, as well as reduce the costs of clinical treatment and discovery research.


Asunto(s)
Antibacterianos/farmacología , Biopelículas/efectos de los fármacos , Fibrosis Quística/microbiología , Pulmón/microbiología , Pseudomonas aeruginosa/fisiología , Staphylococcus aureus/fisiología , Animales , Biopelículas/crecimiento & desarrollo , Colistina/farmacología , Recuento de Colonia Microbiana , Disección , Floxacilina/farmacología , Humanos , Linezolid/farmacología , Pulmón/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Viabilidad Microbiana/efectos de los fármacos , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/aislamiento & purificación , Esputo/microbiología , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/aislamiento & purificación , Porcinos
11.
J Hosp Infect ; 111: 35-39, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33577834

RESUMEN

BACKGROUND: The coronavirus disease 2019 pandemic has resulted in high levels of exposure of medical workers to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Hand decontamination is one of the actions recommended to reduce the risk of infection. AIM: Two disinfectants - BIAKOS antimicrobial skin and wound cleanser (AWC) and AWC2 (Sanara MedTech, Fort Worth, TX, USA) - were tested to determine whether they can inactivate SARS-CoV-2 upon contact or as a coating applied before contact with the virus. METHODS: The ability of AWC and AWC2 to inactivate SARS-CoV-2 was tested in liquid and dried form on plastic surfaces and porcine skin. FINDINGS: AWC and AWC2 were effective in reducing the infectious titre of SARS-CoV-2 in liquid form during application and in dried form 4 h after application. Virus on skin was reduced up to 2 log10-fold and 3.5 log10-fold after treatment with AWC and AWC2, respectively. CONCLUSION: Application of AWC and AWC2 to skin reduces the level of SARS-CoV-2 and the risk of infection.


Asunto(s)
Antivirales/administración & dosificación , Desinfección de las Manos/métodos , Desinfectantes para las Manos/administración & dosificación , Viabilidad Microbiana/efectos de los fármacos , Piel/virología , Administración Tópica , Humanos , Pandemias
12.
Nat Commun ; 12(1): 1224, 2021 02 22.
Artículo en Inglés | MEDLINE | ID: mdl-33619276

RESUMEN

In view of increasing drug resistance, ecofriendly photoelectrical materials are promising alternatives to antibiotics. Here we design an interfacial Schottky junction of Bi2S3/Ti3C2Tx resulting from the contact potential difference between Ti3C2Tx and Bi2S3. The different work functions induce the formation of a local electrophilic/nucleophilic region. The self-driven charge transfer across the interface increases the local electron density on Ti3C2Tx. The formed Schottky barrier inhibits the backflow of electrons and boosts the charge transfer and separation. The photocatalytic activity of Bi2S3/Ti3C2Tx intensively improved the amount of reactive oxygen species under 808 nm near-infrared radiation. They kill 99.86% of Staphylococcus aureus and 99.92% of Escherichia coli with the assistance of hyperthermia within 10 min. We propose the theory of interfacial engineering based on work function and accordingly design the ecofriendly photoresponsive Schottky junction using two kinds of components with different work functions to effectively eradicate bacterial infection.


Asunto(s)
Bismuto/química , Luz , Viabilidad Microbiana/efectos de la radiación , Sulfuros/química , Titanio/química , Animales , Antibacterianos/farmacología , Catálisis/efectos de la radiación , Teoría Funcional de la Densidad , Colorantes Fluorescentes/química , Masculino , Ratones , Viabilidad Microbiana/efectos de los fármacos , Células 3T3 NIH , Nanopartículas/química , Ratas Wistar , Especies Reactivas de Oxígeno/química , Análisis Espectral , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/efectos de la radiación , Electricidad Estática , Temperatura
13.
J Hosp Infect ; 110: 33-36, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33516798

RESUMEN

COVID-19 is a global health threat with a huge number of confirmed cases and deaths all over the world. Human-to-human transmission via respiratory droplets and contact with aerosol-infected surfaces are the major routes of virus spread. Because SARS-CoV-2 can remain in the air and on surfaces from several hours to several days, disinfection of frequently touched surfaces and critical rooms, in addition to observing individual hygiene tips, is required to reduce the virus spreading. Here we report on an investigation into the use of gaseous ozone as a potentially effective sanitizing method against the new coronavirus.


Asunto(s)
/prevención & control , Desinfección/métodos , Viabilidad Microbiana/efectos de los fármacos , Ozono , /efectos de los fármacos , Aerosoles , Humanos
14.
Int J Biol Macromol ; 172: 231-240, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33453253

RESUMEN

Photodynamic inactivation (PDI) is a novel sterilization technology that has proven effective in medicine. This study focused on applying PDI to food packaging, where chitosan (CS) films containing photosensitizing riboflavin (RB) were prepared via solution casting. The CS-RB composite films exhibited good ultraviolet (UV)-barrier properties, and had a visually appealing highly transparent yellow appearance. Scanning electron microscopy (SEM) confirmed even dispersion of RB throughout the CS film. The addition of RB led to improved film characteristics, including the thickness, mechanical properties, solubility, and water barrier properties. The CS-RB5 composite films produced sufficient singlet oxygen under blue LED irradiation for 2 h to inactivate two food-borne pathogens (Listeria monocytogenes and Vibrio parahaemolyticus) and one spoilage bacteria (Shewanella baltica). The CS-RB composite films were assessed as a salmon packaging material, where inhibition of bacterial growth was observed. The film is biodegradable, and has the potential to alleviate the issues associated with the excessive use of petrochemical materials, such as environmental pollution and limited resources. The CS-RB composite films showed potential as a novel environmentally friendly packaging material for shelf-life extension of refrigerated food products.


Asunto(s)
Antibacterianos/química , Quitosano/química , Embalaje de Alimentos/métodos , Tecnología Química Verde , Fármacos Fotosensibilizantes/química , Riboflavina/química , Antibacterianos/farmacología , Antibacterianos/efectos de la radiación , Humanos , Luz , Listeria monocytogenes/efectos de los fármacos , Listeria monocytogenes/crecimiento & desarrollo , Membranas Artificiales , Viabilidad Microbiana/efectos de los fármacos , Fármacos Fotosensibilizantes/farmacología , Fármacos Fotosensibilizantes/efectos de la radiación , Riboflavina/farmacología , Riboflavina/efectos de la radiación , Shewanella/efectos de los fármacos , Shewanella/crecimiento & desarrollo , Oxígeno Singlete/agonistas , Oxígeno Singlete/química , Solubilidad , Vibrio parahaemolyticus/efectos de los fármacos , Vibrio parahaemolyticus/crecimiento & desarrollo , Agua/química
16.
PLoS One ; 16(1): e0244885, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33449947

RESUMEN

Human influenza virus infections occur annually worldwide and are associated with high morbidity and mortality. Hence, development of novel anti-influenza drugs is urgently required. Rice Power® extract developed by the Yushin Brewer Co. Ltd. is a novel aqueous extract of rice obtained via saccharization and fermentation with various microorganisms, such as Aspergillus oryzae, yeast [such as Saccharomyces cerevisiae], and lactic acid bacteria, possessing various biological and pharmacological properties. In our previous experimental screening with thirty types of Rice Power® extracts, we observed that the 30th Rice Power® (Y30) extract promoted the survival of influenza A virus-infected Madin-Darby canine kidney (MDCK) cells. Therefore, to identify compounds for the development of novel anti-influenza drugs, we aimed to investigate whether the Y30 extract exhibits anti-influenza A virus activity. In the present study, we demonstrated that the Y30 extract strongly promoted the survival of influenza A H1N1 Puerto Rico 8/34 (A/PR/8/34), California 7/09, or H3N2 Aichi 2/68 (A/Aichi/2/68) viruses-infected MDCK cells and inhibited A/PR/8/34 or A/Aichi/2/68 viruses infection and growth in the co-treatment and pre-infection experiments. The pre-treatment of Y30 extract on MDCK cells did not induce anti-influenza activity in the cell. The Y30 extract did not significantly affect influenza A virus hemagglutination, and neuraminidase and RNA-dependent RNA polymerase activities. Interestingly, the electron microscopy experiment revealed that the Y30 extract disrupts the integrity of influenza A virus particles by permeabilizing the viral membrane envelope, suggesting that Y30 extract has a direct virucidal effect against influenza A virus. Furthermore, we observed that compared to the ethyl acetate (EtOAc) extract, the water extract of Y30 extract considerably promoted the survival of cells infected with A/PR/8/34 virus. These results indicated that more anti-influenza components were present in the water extract of Y30 extract than in the EtOAc extract. Our results highlight the potential of a rice extract fermented with A. oryzae and S. cerevisiae as an anti-influenza medicine and a drug source for the development of anti-influenza compounds.


Asunto(s)
Aspergillus oryzae/metabolismo , Virus de la Influenza A/efectos de los fármacos , Oryza/química , Oryza/microbiología , Extractos Vegetales/farmacología , Saccharomyces cerevisiae/metabolismo , Agua/química , Acetatos/química , Animales , Antivirales/farmacología , Perros , Fermentación , Virus de la Influenza A/crecimiento & desarrollo , Virus de la Influenza A/fisiología , Células de Riñón Canino Madin Darby , Viabilidad Microbiana/efectos de los fármacos
17.
Artículo en Inglés | MEDLINE | ID: mdl-33470889

RESUMEN

In this study, we investigated the interaction of submicron-sized bioplastics with environmentally and clinically important bacteria under seawater and sediment conditions. To examine the relationship between submicron-sized bioplastics and bacteria in seawater and sediment, we focused on the bacterial activation and their biochemical key events toward the protein, carbohydrate, lipid, and antioxidant response. In addition, culture-dependent biofilm formation on submicron-sized bioplastics and their characterization was performed. The results indicated that selected bacteria increased their viability both in seawater and sediment with the submicron-sized bioplastics in that the bioplastics decreased their mass at the level of 10-23%. However, the activation level and mechanism affected the polymer type, bacteria, and environmental media, and submicron-sized bioplastics promoted biofilm formation with enhancing basophilic characteristics of biofilms.


Asunto(s)
Sedimentos Geológicos/microbiología , Microplásticos/análisis , Polímeros/análisis , Agua de Mar/microbiología , Contaminantes Químicos del Agua/análisis , Bacterias/efectos de los fármacos , Bacterias/metabolismo , Biodegradación Ambiental , Biopelículas/efectos de los fármacos , Biopelículas/crecimiento & desarrollo , Sedimentos Geológicos/química , Viabilidad Microbiana/efectos de los fármacos , Microplásticos/toxicidad , Tamaño de la Partícula , Polímeros/metabolismo , Polímeros/toxicidad , Agua de Mar/química , Microbiología del Agua , Contaminantes Químicos del Agua/toxicidad
18.
Nat Commun ; 12(1): 526, 2021 01 22.
Artículo en Inglés | MEDLINE | ID: mdl-33483514

RESUMEN

Aciduric bacteria that can survive in extremely acidic conditions (pH < 4.0) are challenging to the current antimicrobial approaches, including antibiotics and photodynamic bacteria inactivation (PDI). Here, we communicate a photosensitizer design concept of halogenation of fluorescein for extremely acidic PDI. Upon halogenation, the well-known spirocyclization that controls the absorption of fluorescein shifts to the acidic pH range. Meanwhile, the heavy atom effect of halogens boosts the generation of singlet oxygen. Accordingly, several photosensitizers that could work at even pH < 2.0 were discovered for a broad band of aciduric bacteria families, with half maximal inhibitory concentrations (IC50) lower than 1.1 µM. Since one of the discovered photosensitizers is an FDA-approved food additive (2',4',5',7'-tetraiodofluorescein, TIF), successful bacteria growth inhibition in acidic beverages was demonstrated, with greatly extended shelf life from 2 days to ~15 days. Besides, the in vivo PDI of Candidiasis with TIF under extremely acidic condition was also demonstrated.


Asunto(s)
Antibacterianos/farmacología , Bacterias/efectos de los fármacos , Fluoresceína/farmacología , Luz , Fármacos Fotosensibilizantes/farmacología , Ácidos/química , Animales , Bacterias/clasificación , Bacterias/efectos de la radiación , Femenino , Fluoresceína/química , Halogenación , Humanos , Concentración de Iones de Hidrógeno , Ratones Endogámicos ICR , Viabilidad Microbiana/efectos de los fármacos , Viabilidad Microbiana/efectos de la radiación , Estructura Molecular , Oxígeno Singlete/química , Oxígeno Singlete/metabolismo
19.
Carbohydr Polym ; 254: 117296, 2021 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-33357864

RESUMEN

A fully biobased benzoxazine monomer, V-fa (using vanillin and furfurylamine) was grafted onto chitosan (CS) at different weight ratios (CXVY) using "grafting to" benign Schiff base chemistry. Incorporation of V-fa onto CS increased the tensile strength and improved chemical resistance of the CS-graft-V-fa films. Reversible labile linkages, expansion of CS galleries and leaching out of phenolic species from biobased polymer films led to an improved antibacterial activity against Staphylococcus aureus, which is ∼125 times higher than the bare CS film, V-fa and oligomeric V-fa. The leached out species from films were analyzed extensively by NMR, FTIR, GPC, ABTS and HRMS analysis. Oxidative-stress seems to be responsible for antibacterial activity. Current work illustrates an attractive synthetic approach and the improved antibacterial performance of biobased CS-graft-poly(V-fa) films which may hold as a potential alternative for wound-healing and implant applications in future.


Asunto(s)
Antibacterianos/química , Antioxidantes/química , Benzoxazinas/química , Quitosano/química , Liberación de Fármacos , Staphylococcus aureus/efectos de los fármacos , Benzaldehídos/química , Furanos/química , Interacciones Hidrofóbicas e Hidrofílicas , Viabilidad Microbiana/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal/efectos de los fármacos , Solventes/química , Staphylococcus aureus/metabolismo , Resistencia a la Tracción , Trasplante/métodos , Agua/química , Cicatrización de Heridas/efectos de los fármacos
20.
Food Chem ; 338: 128134, 2021 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-33091996

RESUMEN

Lactic acid bacteria can improve their resistance to adverse environments through the formation of biofilm. This study found that adding different buffer salts in culture medium had a great impact on the freeze-drying survival rate of the Lactobacillus plantarum LIP-1, which could be linked to biofilm formation. Transcriptome data showed that potassium ions in buffer salt increased the expression of the luxS gene in the LuxS/autoinducer-2 (AI-2) quorum sensing system and increase synthesis of the quorum sensing signal AI-2. The AI-2 signal molecules up-regulated the cysE gene, which helps to promote biofilm formation. By adding a biofilm inhibitor, d-galactose, and performing a real-time quantitative polymerase chain reaction experiment, we found that d-galactose could down-regulated the luxS and cysE genes, reduced biofilm formation, and decreased the freeze-drying survival rate. The results of this study showed that promoting biofilm formation using appropriate buffer salts may lead to better freeze-drying survival rates.


Asunto(s)
Biopelículas/crecimiento & desarrollo , Medios de Cultivo/química , Liofilización/métodos , Lactobacillus plantarum/efectos de los fármacos , Lactobacillus plantarum/fisiología , Viabilidad Microbiana/efectos de los fármacos , Sales (Química)/farmacología , Proteínas Bacterianas/metabolismo , Biopelículas/efectos de los fármacos , Tampones (Química) , Liasas de Carbono-Azufre/genética , Relación Dosis-Respuesta a Droga , Homoserina/análogos & derivados , Homoserina/metabolismo , Lactobacillus plantarum/citología , Lactobacillus plantarum/metabolismo , Lactonas/metabolismo , Percepción de Quorum/efectos de los fármacos , Tasa de Supervivencia
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