ABSTRACT
Staphylococcus aureus is a Gram-positive bacterium responsible for a number of diseases and has demonstrated resistance to conventional antibiotics. This study aimed to evaluate the antibacterial activity of eugenol and its derivatives allylbenzene, 4-allylanisole, isoeugenol and 4-allyl-2,6-dimethoxyphenol against the S. aureus NorA efflux pump (EP) in association with norfloxacin and ethidium bromide. The antibacterial activity of the compounds was assessed using the broth microdilution method to determine the minimum inhibitory concentration (MIC). A reduction in the MIC of ethidium bromide (a substrate for several efflux pumps) or norfloxacin was used as a parameter of EP inhibition. Molecular modeling studies were used to predict the 3D structure and analyze the interaction of selected compounds with the binding pocket of the NorA efflux pump. Except for 4-allylanisole and allylbenzene, the compounds presented clinically effective antibacterial activity. When associated with norfloxacin against the SA 1199B strain, 4-allyl-2,6-dimethoxyphenol eugenol and isoeugenol caused significant reduction in the MIC of the antibiotic, demonstrating synergistic effects. Similar effects were observed when 4-allyl-2,6-dimethoxyphenol, allylbenzene and isoeugenol were associated with ethidium bromide. Together, these findings indicate a potential inhibition of the NorA pump by eugenol and its derivatives. This in vitro evidence was corroborated by docking results demonstrating favorable interactions between 4-allyl-2,6-dimetoxypheno and the NorA pump mediated by hydrogen bonds and hydrophobic interactions. In conclusion, eugenol derivatives have the potential to be used in antibacterial drug development in strains carrying the NorA efflux pump.
Subject(s)
Bacterial Proteins/metabolism , Eugenol/analogs & derivatives , Multidrug Resistance-Associated Proteins/metabolism , Staphylococcus aureus/metabolism , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Bacterial Proteins/antagonists & inhibitors , Binding Sites , Ethidium/pharmacology , Eugenol/metabolism , Eugenol/pharmacology , Hydrogen Bonding , Microbial Sensitivity Tests , Molecular Docking Simulation , Multidrug Resistance-Associated Proteins/antagonists & inhibitors , Norfloxacin/pharmacology , Staphylococcus aureus/drug effectsABSTRACT
Beaches are fundamental habitats that regulate the functioning of several coastal processes and key areas contributing to national and local budgets. In this study we provide the first large-scale systematic survey of anthropogenic litter on Brazilian beaches, covering a total of 35 degrees of latitude, recording the litter type, its use and size. Plastic comprised the most abundant litter type, followed by cigarette butts and paper. Small pieces (<5 cm) were dominant among litter size-classes and food-related use was associated to most litter recorded types. Generalized additive models showed that proximity to estuarine run-offs was the main driver to beach litter accumulation, reinforcing river drainages as the primary route of litter coastal pollution. Also, the Clean-Coast Index evidenced there was not a pattern of beach litter pollution among regions, which denotes that actions regarding marine pollution must be taken by all state governances of the country.
Subject(s)
Bathing Beaches , Environmental Monitoring , Waste Products , Brazil , PlasticsABSTRACT
Regulation of wound pH from alkaline to acidic is a simple and powerful approach to reduce wound microbial colonization and infection. Here, we present a nanocomposite material possessing intrinsic acidic surface pH as an innovative antimicrobial wound dressing. This material comprises an agarose matrix nanocomposite containing nanoparticles (NPs) of the cesium salt of phosphotungstic heteropolyacid (Cs2.5H0.5PW12O40). Self-supporting films were prepared by a casting method incorporating 5-20 wt % Cs2.5H0.5PW12O40 NPs into the matrix. Films are flexible with tensile strengths between 28.55 and 32.15 MPa and exhibit broad biocidal activity against neutralophilic pathogens, including Gram-positive bacteria, Gram-negative bacteria, yeast, and filamentous fungi. The nano-antimicrobial Cs2.5H0.5PW12O40 functions as an efficient and self-controlled proton delivery agent that lowers the surface pH of the nanocomposites to the range 7.0 > pH ≥ 3.0. Nanocomposite films containing 20 wt % Cs2.5H0.5PW12O40 NPs presented a surface pH of 3.0 and highest antimicrobial activity. Using quantitative reverse transcription polymerase chain reaction, we demonstrated that the antimicrobial mechanism of the nanocomposites is acid-induced because of the transcriptional induction of glutamate-dependent acid resistance genes in Escherichia coli. Additionally, nanocomposite films do not damage skin according to an in vivo rabbit skin model with no derived edema or erythema. The wound care safety of this material is due to low release of heavy metal heteropolyanions ([PW12O40]3-), no nanoparticle leaching, and proton controlled release resulting in nonirritating acid levels for human skin models.
Subject(s)
Anti-Bacterial Agents/chemistry , Bandages , Infection Control/methods , Nanocomposites/chemistry , Sepharose/chemistry , Animals , Anti-Bacterial Agents/pharmacology , Bacteria/drug effects , Humans , Rabbits , Skin/drug effectsABSTRACT
This study was carried out to test the essential oil from C. ambrosioides leaves and its main constituent, α-Terpinene, in an antibacterial activity assay. As well, it was evaluated ability reduce resistance to norfloxacin and ethidium bromide was compared the Staphylococcus aureus 1199B whith 1199 wild type strain. The MIC of the C. ambrosioides essential oil and α-Terpinene were determined by microdilution method. The MIC of the essential oil and α-Terpinene presented a valueâ¯≥â¯1024⯵g/mL. However, when associated with antibacterials, the essential oil from C. ambrosioides leaves significantly reduced the MIC of antibiotics and ethidium bromide, characterizing an efflux pump inhibition. The C. ambrosioides essential oil, despite having no direct antibacterial activity against the S. aureus 1199B strain, showed a potentiating action when associated with antibacterial agents, this being attributed to an inhibition of efflux pumps.
Subject(s)
Anti-Bacterial Agents/pharmacology , Bacterial Proteins/antagonists & inhibitors , Chenopodium ambrosioides/chemistry , Monoterpenes/pharmacology , Multidrug Resistance-Associated Proteins/antagonists & inhibitors , Oils, Volatile/pharmacology , Cyclohexane Monoterpenes , Drug Resistance, Bacterial/drug effects , Microbial Sensitivity Tests , Norfloxacin/pharmacology , Oils, Volatile/chemistry , Plant Leaves/chemistry , Staphylococcus aureus/drug effects , Staphylococcus aureus/metabolismABSTRACT
RATIONALE: Biomass exposure is an important risk factor for chronic obstructive pulmonary disease (COPD). However, the time-course behavior of FEV1 in subjects exposed to biomass is unknown. OBJECTIVES: We undertook this study to determine the FEV1 rate decline in subjects exposed to biomass. METHODS: Pulmonary function was assessed every year in a Mexican cohort of patients with COPD associated with biomass or tobacco during a 15-year follow-up period. MEASUREMENTS AND MAIN RESULTS: The mean rate of decline was significantly lower for the biomass exposure COPD group (BE-COPD) than for the tobacco smoke COPD group (TS-COPD) (23 vs. 42 ml, respectively; P < 0.01). Of the TS-COPD group, 11% were rapid decliners, whereas only one rapid decliner was found in the BE-COPD group; 69 and 21% of smokers versus 17 and 83% of the BE-COPD group were slow decliners and sustainers, respectively. A higher FEV1 both as % predicted and milliliters was a predictive factor for decline for BE-COPD and TS-COPD, whereas reversibility to bronchodilator was a predictive factor for both groups when adjusted by FEV1% predicted and only for the TS-COPD group when adjusted by milliliters. CONCLUSIONS: In the biomass exposure COPD group the rate of FEV1 decline is slower and shows a more homogeneous rate of decline over time in comparison with smokers. The rapid rate of FEV1 decline is a rare feature of biomass-induced airflow limitation.
Subject(s)
Biomass , Environmental Exposure/adverse effects , Forced Expiratory Volume , Pulmonary Disease, Chronic Obstructive/physiopathology , Smoke/adverse effects , Aged , Cohort Studies , Female , Humans , Male , Smoking/physiopathologyABSTRACT
Introducción: La verificación y seguimiento de la presencia de microrganismos indicadores de la calidaddel agua es imprescindible debido al riesgo que representan para la población que la utiliza para consumo, recreación o deporte. Los reservorios acuíferos de Corrales de San Luis Beltrán, Atlántico, Colombia, son fuente de sustento de las comunidades campesinas aledañas, animales y plantas de la reserva; sin embargo, su calidad microbiológica no ha sido estudiada. Objetivo: Evaluar la calidad sanitaria del agua de reservorios acuíferos de Corrales de San Luis Beltrán. Materiales y métodos: Se realizaron muestreos de aguas superficiales y sedimento de reservorios acuíferos de Corrales de San Luis Beltrán, y se midieron in situ algunos parámetros fisicoquímicos (temperatura, pH, y oxígeno disuelto), y la calidad microbiológica (coliformes totales, coliformes fecales y bacterias reductoras de sulfato). Resultados: Se presentaron concentraciones bajas de oxígeno disuelto (2,71 mg/L), temperatura promedio de 26 °C y pH ligeramente básico (8,1). Los coliformes totales oscilaron entre 1,0x104 y 1,3x107 UFC/100 mL y los fecales entre 0 y 1,3x105 UFC/100 mL. Se encontró una correlación negativa entre el pH y los coliformes totales, y entre el oxígeno disuelto y los coliformes fecales; y una correlación positiva entre los coliformes fecales y la temperatura. Los recuentos de bacterias reductoras de sulfato fueron superiores a 103 UFC/100 g...
Introduction: The verification and monitoring of indicator microorganisms of water quality is essential.A low water quality may represent a risk for human health, because human populations frequently use it for consumption, recreation, or sport. Water reservoirs situated in Corrales de San Luis Beltran, Atlantico, Colombia, are source of sustenance to local peasant communities, animals, and plants around the village. However, the microbiological quality has not been established. Objective: To assess the sanitary water quality from Corrales de San Luis Beltran. Materials and methods: Surface water and sediment were sampled and some physicochemical parameters (temperature, pH, and dissolved oxygen), and the microbiological quality (total coliforms, fecal coliforms, and sulfate-reducing bacteria) were measured in situ. Results: The analysis showed low dissolved oxygen levels (2,71 mg/L), an average temperature of 26 °C and a slightly basic pH (8,1). Total coliform counts ranged from 1,0x104 and 1,3 x 107 CFU/100 mL and fecal coliform between 0 and 1,3 x 105 CFU/100 g. A negative correlation occurred between pH and total coliform as well as between dissolved oxygen and fecal coliforms. In addition, a positive correlation occurred between fecal coliform and temperature. The number of sulfate-reducing bacteria was more than 103 CFU/100 mL...
Subject(s)
Humans , Coliforms , Sulfur-Reducing Bacteria , Water QualityABSTRACT
A apnéia obstrutiva do sono é uma síndrome caracterizada pelo colapso repetitivo das estruturas que formam o espaço aéreo posterior, que impedem e ou reduzem a passagem do ar durante o sono. Consequentemente há uma queda na saturaçäo de oxigênio do sangue e toda uma série de sinais e sintomas correlacionados à doença, inclusive o risco de morte. Os autores relatam caso clínico de paciente retrognata, com má oclusäo de Classe II, com espaço buco-faríngeo inferior a 6mm, que foi diagnosticado na análise polissonográfica como portador da síndrome. O plano de tratamento executado foi o avanço da mandíbula, pela técnica sagital bilateral, com reposicionamento anterior do músculo genioglosso e a suspensäo do osso hióide. A análise polissonográfica foi repetida 1 ano após o tratamento ortodôntico sendo classificada como sucesso
Subject(s)
Humans , Male , Female , Malocclusion, Angle Class II , Retrognathia , Sleep Apnea Syndromes/therapy , OrthodonticsABSTRACT
Uma das inovaçöes mais importantes em cirurgia e traumatologia bucomaxillofacial foi o advento da fixaçäo óssea por meio do uso de placas e parafusos metálicos. Algumas empresas substituíram metais por polímeros reabsorvíveis. Assim, o propósito deste artigo é relatar a experiência do uso dos sistemas Lactosorb e Bioix na fixaçäo óssea em cirurgia ortognática, apresentando alguns comentários e críticas sobre o procedimento
Subject(s)
Humans , Male , Female , Adult , Bone Screws , Bone Plates , Surgery, Oral/trendsABSTRACT
En el presente trabajo se revisaron 244 pacientes en edad pediátrica que ingresaron al hospital San Ignacio con el diagnóstico de Apendicitis Aguda y que fueron intervenidos quirúrgicamente con el mimso diagnóstico en el lapso de tiempo comprendido entre enero de 1976 y junio de 1983, haciéndose principal énfasis en el análisis del tiempo de evolución y presentación de las manifestaciones clínica, paraclínicas y su correlación anatomopatológica, tipo de manejo y pre y postoperatorio al igual que la evolución, complicaciones y costo.