Chemical composition, antioxidant and antimicrobial activities of essential oil from the aerial parts of Chuquiraga arcuataHarling grown in the highlands of Ecuador / Composición química, actividades antioxidantes y antimicrobianas del aceite esencial de las partes aéreas de Chuquiraga arcuataHarling cultivado en las tierras altas del Ecuador

Thechemical composition, antioxidant and antimicrobial activities of the essential oil from aerial parts (leaves and flowers) of Chuquiraga arcuataHarling grown in the Ecuadorian Andes were studied. One hundred and twenty-six compounds were identified in the essential oil. Monoterpene hydrocarbons (45.8%) and oxygenated monoterpenes (44.1%) had the major percentages. The most abundant compounds were camphor (21.6%), myrcene (19.5%), and 1,8-cineole (13.4%). Antioxidant activity was examined using DPPH, ABTS,and FRAP assays. The essential oil had a moderate scavenging effect and reduction of ferric ion capacity through FRAP assay. Antimicrobial activity of the essential oil was observed against four pathogenic bacteria and a fungus. The essential oil exhibited activity against all microorganism strains under test, particularly against Candida albicansand Staphylococcus aureuswith MICs of 2.43-12.10 µg/mL.

Se estudió la composición química, actividades antioxidantes y antimicrobianas del aceite esencial procedente de las partes aérea (hojas y flores) de Chuquiraga arcuataHarling cultivadas en los Andes ecuatorianos. Se identificaron 126 compuestos en el aceite esencial. Los hidrocarburos monoterpénicos (45,8%) y los monoterpenos oxigenados (44,1%) tuvieron el mayor porcentaje. Los compuestos más abundantes fueron alcanfor (21,6%), mirceno (19,5%) y 1,8-cineol (13,4%). La actividadantioxidante se examinó mediante ensayos DPPH, ABTS y FRAP. El aceite esencial tuvo un efecto eliminador moderado y una reducción de la capacidad de iones férricos mediante el ensayo FRAP. Se observó actividad antimicrobiana del aceite esencial contra cuatro bacterias y un hongo patógenos. El aceite esencial mostró actividad contra todas las cepas de microorganismos bajo prueba, particularmente contra Candida albicansy Staphylococcus aureuscon CMI de 2,43-12,10 µg/mL.

A novel nanocomposite based on mycosynthesized bimetallic zinc-copperoxide nanoparticles, nanocellulose and chitosan: Characterization, antimicrobial and photocatalytic activities

BACKGROUND Recently, nanomaterials have received much attention due to their important role in solving medical and environmental problems. In the present study, a novel nanocomposite based on mycosyn thesized bimetallic zinc-copper oxides nanoparticles, nanocellulose, and chitosan was ready through an ecofriendly method. Characterization, antimicrobial and photocatalytic activities were evaluated. RESULTS The result revealed that the prepared nanocomposite exhibited antibacterial activity against Bacillus subtilis, Escherichia coli and Staphylococcus aureus, where MICs were 7.81, 31.25 and 62.5 lg mL 1 . As well, the nanocomposite showed potential antifungal activity against Aspergillus brasiliensis where MIC was 7.81 lg mL 1 , but had minimal antifungal efficacy against Cryptococcus neo formans and Candida albicans where the MIC was 250 lg mL 1 for each other. Furthermore, the nanocom posite had photocatalytic activity. The bimetallic and nanocomposite materials were characterized via physiochemical and topographic analysis. CONCLUSIONS In conclusion, the prepared nanocomposite based on mycosynthesized bimetallic zinc copper oxides nanoparticles nanocellulose and chitosan has antimicrobial and photocatalytic activities which can be applied to various environments

Estudio biodirigido de metabolitos secundarios con actividad antimicrobiana y aislamiento de D-pinitol de semillas de Leucaena esculenta y L. leucocephala / Bio-guided study of secondary metabolites with antimicrobial activity and isolation of D-pinitol from Leucaena esculenta and L. leucocephala seeds

Phytochemical bio-guided studies are used to find compounds with biological activity. Flavonoids from seeds of Leucaena species have antimicrobial activity in strains of medical interest, therefore, fresh seeds were collected from the town of Tlayacapan, Morelos, Mexico. The methanolic extracts were obtained by the maceration technique, targeted fractionation was performed using adsorption and molecular exclusion chromatographic techniques; to observe the antimicrobial activity, agar diffusion techniques were used; spectrometric and spectroscopic techniques were used for the characterization of D-pinitol, resulting from the fractionation of L. leucocephala. Antimicrobial activity was found on strains of Escherichia coli CUSI and Staphylococcus aureus ATCC 29213 of the most polar fractions, identifying the responsible compounds by HPLC: caffeic acid, gallic acid, p-coumaric acid, quercetin, catechin and apigenin, these compounds can inhibit the activation enzymatic, synthesis of nucleic acids and proteins, chelating with different ions, etc.

Los estudios biodirigidos fitoquímicos son empleados para encontrar compuestos con actividad biológica. Los flavonoides de semillas de especies de Leucaena son reportados por tener actividad antimicrobiana sobre cepas de interés médico, por tanto, se colectaron semillas frescas de la localidad de Tlayacapan, Morelos, México. Se obtuvieron los extractos metanólicos mediante la técnica de maceración, el fraccionamiento dirigido se realizó empleando técnicas cromatográficas de adsorción y exclusión molecular; la actividad antimicrobiana se determinó mediante técnicas de difusión en agar; se utilizaron técnicas espectrométricas y espectroscópicas para la caracterización del D-pinitol, resultado del fraccionamiento de L. leucocephala. Se encontró actividad antimicrobiana sobre cepas de Escherichia coli CUSI y Staphylococcus aureus ATCC 29213 de las fracciones más polares, identificando los compuestos responsables vía HPLC: ácido caféico, ácido gálico, ácido p-cumárico quercetina, catequina y apigenina, dichos compuestos pueden inhibir activación enzimática, síntesis de ácidos nucleicos y proteínas, quelarse con diferentes iones, etc.

Antimicrobial activity of limonene: integrative review / Actividad antimicrobiana del limoneno: revisión integrativa

Limonene is the main component of citrus essential oils, and can reach a concentration of up to 96%. Popularly known for its potential therapeutic effects on the body, among these we point out its broad antimicrobial activity against various types of pathogens. Therefore, the purpose of this study was to address the antimicrobial and antifungal properties of limonene compared to microorganisms of interest in dentistry, based on a bibliometric study and literature review. The following databases were analyzed: PubMed, Google Scholar, SciELO and Science Direct, from which ten articles published between 2011-2021 were selected. Most of results indicate a satisfactory antimicrobial potential, besides providing important data and perspectives regarding the indication and clinical use, in addition to innovative therapeutic modalities for diseases that affect the oral cavity, such as tooth decay, periodontal disease and candidosis.

El limoneno es el componente principal de los aceites esenciales cítricos, y puede alcanzar una concentración de hasta el 96%. Popularmente conocido por sus potenciales efectos terapéuticos en el organismo, entre ellos se destacan su amplia actividad antimicrobiana frente a diversos tipos de patógenos. Por lo tanto, el objetivo de este estudio fue abordar las propiedades antimicrobianas y antifúngicas del limoneno en comparación con microorganismos de interés en la odontología, a partir de un estudio bibliométrico y una revisión bibliográfica. Se analizaron las siguientes bases de datos: PubMed, Google Scholar, SciELO y Science Direct, de las cuales se seleccionaron diez artículos publicados entre 2011-2021. La mayoría de los resultados indican un potencial antimicrobiano satisfactorio, además de proporcionar datos y perspectivas importantes con respecto a la indicación y el uso clínico, así como modalidades terapéuticas innovadoras para enfermedades que afectan la cavidad oral, como caries, enfermedad periodontal y candidosis.

Phytochemical profile, in vitro activities, and toxicity of optimized Eugenia uniflora extracts / Perfil fitoquímico, actividades in vitro y toxicidad de extractos optimizados de Eugenia uniflora

In this study, we investigated the influence of mixture design on the chemical profile of Eugenia unifloraleaves, evaluating the antioxidant and antimicrobial activities, the toxic and hemolytic potential, with the focus on the improvement of the polyphenol's extraction for incorporation of the extract in semi-solid forms with antifungal action. The chemical analysis was evaluated by UV-Vis and HPLC. The antimicrobial, antioxidant, and hemolytic activities were monitored. The flavonoid content ranged from 2.63-7.98 %w/w and tannins from 5.42-18.29 %w/w. The extract consisted of gallic acid (0.09-1.29%; w/w), ellagic acid (0.09-0.37%; w/w), and myricitrin (0.18-1.20%; w/w). The most successful solvent system with the highest level of active extract was water: ethanol: propylene glycol. The extracts showed fungicidal properties (3.9 µg/mL), high antioxidant activity (IC50: 9.50 µg/mL), and low toxicity. These solvent mixtures can improve the in vitro bioactivities when compared to pure solvents and this result demonstrates the importance of mixture designs as useful tools for creating high-quality herbal products and elucidate the potential of E. uniflora glycolic extracts as active herbal pharmaceutical ingredients in topical delivery systems.

En este estudio investigamos la influencia del diseño de mezclas en el perfil químico de hojas de Eugenia uniflora, evaluando las actividades antioxidantes y antimicrobianas, el potencial tóxico y hemolítico, con el foco en la mejora de la extracción de polifenoles para la incorporación del extracto en formas semi-sólidas con acción antifúngica. El análisis químico se evaluó mediante UV-Vis y HPLC. Se monitorizaron las actividades antimicrobianas, antioxidantes y hemolíticas. El contenido de flavonoides osciló entre 2,63 y 7,98% p/p and taninos de 5,42-18,29% p/p. El extracto consistió en ácido gálico (0.09-1.29%; p/p), ácido elágico (0.09-0.37%; p/p) y miricitrina (0.18-1.20%; p/p). El sistema de disolventes más exitoso con el nivel más alto de extracto activo fue agua: etanol: propilenglicol. Los extractos mostraron propiedades fungicidas (3.9 µg/mL), alta actividad antioxidante (IC50: 9.50 µg/mL) y baja toxicidad. Estas mezclas de disolventes pueden mejorar las bioactividades in vitro en comparación con los disolventes puros y este resultado demuestra la importancia de los diseños de mezclas como herramientas útiles para crear productos a base de hierbas de alta calidad y dilucidar el potencial de los extractos glicólicos de E. uniflora como ingredientes farmacéuticos a base de hierbas en sistemas de entrega activos.

Chemical composition, antioxidant, antimicrobial activity, toxicity, genetic analysis and popular use of Eugenia luschnathiana (O. Berg) Klotzsch ex B. D. Jacks: a literature review / Composición química, actividad antioxidante, antimicrobiana, toxicidad, análisis genético y uso popular de Eugenia luschnathiana (O. Berg) Klotzsch ex B. D Jack: una revisión de la literatura

This review describes the geographical distribution, botanical data, popular use, chemical composition, pharmacological activities and genetic aspects related to Eugenia luschnathiana, a native Brazilian plant popularly known as "bay pitomba". E. luschnathiana leaves are characterized morphologically by the presence of a petiole, an attenuated base, acuminated apex, elliptical shape, and parallel venation. The major chemical compounds found in E. luschnathiana are sesquiterpenes. Literature reports showed that E. luschnathiana extracts have antioxidant properties and antimicrobial activity against Gram-negative and Gram-positive bacteria. The extractsfrom the leaf, fruit and stem, and a concentrated residual solution of its essential oil, displayed negligible toxicity. Lastly, a cytogenetic analysis indicated that some markers can be used for the study of genetic diversity, population structure, and genetic improvements. The information available on E. luschnathiana supports the hypothesis that this plant may be a source of compounds with promising pharmacological activity.

Esta revisión describe la distribución geográfica, datos botánicos, uso popular, composición química, actividad farmacológica y el análisis genético de Eugenia luschnathiana, una planta originaria del Brasil conocida popularmente como "pitomba da baía". Las hojas de E. luschnathiana se caracterizan por la presencia de pecíolo, base atenuada, ápice acuminado, forma elíptica y venación paralela. Su composición química presenta mayormente sesquiterpenos. Los informes en la literatura muestran que los extractos de E. luschnathiana presentan propiedades antioxidantes y actividad antimicrobiana contra las bacterias Gram-negativas y Gram-positivas. Los extractos de la hoja, fruto y tallo, y una solución residual concentrada del aceite esencial, presentaron baja toxicidad. Por último, un análisis citogenético indicó que algunos marcadores pueden utilizarse para estudios de diversidad genética, estructura poblacional y mejoramiento genético. Las informaciones disponibles acerca de E. luschnathiana proponen la hipótesis de que esta planta puede ser una fuente de compuestos con actividad farmacológica prometedora.

Antimicrobial activity of the essential oils from the leaves and stems of Amomum rubidum Lamxay & N. S. Lý / Actividad antimicrobiana de los aceites esenciales de las hojas y tallos de Amomum rubidum Lamxay & N. S. Lý

This paper described the chemical compositions and antimicrobial activity of the essential oils from the leaves and stem of Amomum rubidumLamxay & N. S. Lý, collected from Bidoup Nui Ba National Park, Lam Dong, Vietnam. The essential oils were obtained by hydrodisitllation method while antimicrobial activity was evaluetd by microdilution broth susceptibility assay. The main constituents of the leaf essential oil were identified as 1,8-cineole (37.7%), δ-3-carene (19.5%) and limonene (16.3%) while δ-3-carene (21.9%), limonene (17.8%) and ß-phellandrene (14.6%) dominated in the stem essentialoil. The leaf and stem essential oils displayed stronger inhibition of Pseudomonas aeruginosa with MIC of 25 µg/mLand 50 µg/mL respectively. The stem essential oil was active against Candida albicans (MIC, 50 µg/mL) while both essential oils inhibited the growth of Fusarium oxysporum (MIC 50 µg/mL). This is the first report on chemical constituents and antimicrobial activity of the essential oils of A. rubidum.

Este artículo describe la composición química y la actividad antimicrobiana de aceites esenciales de las hojas y el tallo de Amomum rubidum Lamxay & N. S. Lý recolectados del Parque Nacional Bidoup Nui Ba, Lam Dong, Vietnam. Los aceites esenciales se obtuvieron mediante el método de hidrodisitilación, mientras que la actividad antimicrobiana se evaluó mediante un ensayo de susceptibilidad de caldo de microdilución. Los principales componentes del aceite esencial de la hoja se identificaron como 1,8-cineol (37,7%), δ-3-careno (19,5%) y limoneno (16,3%), mientras que δ-3-careno (21,9%), limoneno (17,8 %) y ß-felandreno (14,6%) dominaron en el aceite esencial del tallo. Los aceites esenciales de hoja y tallo mostraron una inhibición más fuerte de Pseudomonas aeruginosa con un MIC de 25 µg/mL y 50 µg/mL, respectivamente. El aceite esencial del tallo fue activo contra Candida albicans (MIC, 50 µg/mL) mientras que ambos aceites esenciales inhibieron el crecimiento de Fusarium oxysporum (MIC 50 µg/mL). Este es el primer informe sobre los componentes químicos y la actividad antimicrobiana de los aceites esenciales de A. rubidum.

Evaluación in vitro de la actividad antimicrobiana de un propóleo chileno sobre muestras clínicas de exudados bucofaríngeos y cepas ATCC / In vitro evaluation of the antimicrobial activity of a Chilean propolis on clinical samples of oropharyngeal exudates

Propolis is a substance manufactured by Apis mellifera and has been widely used in folk medicine due to its high concentration of bioactive compounds. The purpose of the following study was to characterize and evaluate in vitro the antimicrobial properties of propolis on clinical samples and ATCC strains. The chemical characterization of propolis presents a concentration of total polyphenols of 247 ± 9 mg EAG g-1 MS, flavones and flavonols 75± 4 mg EQ g-1 MS, flavanonones and flavanonols 118 ± 11 EP g-1 MS. HPLC-DAD identified apigenin, galangin, phenethyl ester of caffeic acid and pinocembrin, in addition to 16 compounds by HPLC MS/MS. Chilean propolis is a natural antimicrobial, showing effectiveness in strains ATCC Staphylococcus aureus, Candida albicans, Trichophyton rubrum and clinical samples of Staphylococcus aureus unlike Escherichia coli. These results demonstrate the antimicrobial effectiveness of the synergy of compounds present in propolis against different human pathogens.

El propóleos es una substancia fabricada por Apis mellifera y ha sido utilizado ampliamente en la medicina popular debido a su alta concentración de compuestos bioactivos. El propósito del siguiente estudio fue caracterizar y evaluar in vitro las propiedades antimicrobianas del propóleos sobre muestras clínicas y cepas ATCC. La caracterización química de propóleos presenta una concentración de polifenoles totales de 247 ± 9 mg EAG g-1 de MS, flavonas y flavonoles 75 ± 4 mg EQ g-1 de MS, flavanononas y flavanonoles 118 ± 11 EP g-1 de MS. Mediante HPLC-DAD se identificó apigenina, galangina, fenetil éster del ácido cafeico y pinocembrina, además de 16 compuestos mediante HPLC MS/MS. El propóleos chileno es un antimicrobiano natural, observándose efectividad en cepas ATCC Staphylococcus aureus, Candida albicans, Trichophyton rubrum y muestras clínicas de Staphylococcus aureus a diferencia de Escherichia coli. Estos resultados demuestran la efectividad antimicrobiana de la sinergia de compuestos presentes en el propóleos ante diferentes patógenos humanos.

In vitro antimicrobial and antimycobacterial activity and HPLC-DAD screening of phenolics from Chenopodium ambrosioides L

Abstract The main objective of this study was to demonstrate the antimicrobial potential of the crude extract and fractions of Chenopodium ambrosioides L., popularly known as Santa-Maria herb, against microorganisms of clinical interest by the microdilution technique, and also to show the chromatographic profile of the phenolic compounds in the species. The Phytochemical screening revealed the presence of cardiotonic, anthraquinone, alkaloids, tannins and flavonoids. The analysis by HPLC-DAD revealed the presence of rutin in the crude extract (12.5 ± 0.20 mg/g), ethyl acetate (16.5 ± 0.37 mg/g) and n-butanol (8.85 ± 0.11 mg/g), whereas quercetin and chrysin were quantified in chloroform fraction (1.95 ± 0.04 and 1.04 ± 0.01 mg/g), respectively. The most promising results were obtained with the ethyl acetate fraction, which inhibited a greater number of microorganisms and presented the lowest values of MIC against Staphylococcus aureus and Enterococcus faecalis (MIC = 0.42 mg/mL), Pseudomonas aeruginosa (MIC = 34.37 mg/mL), Paenibacillus apiarus (MIC = 4.29 mg/mL) and Paenibacillus thiaminolyticus (MIC = 4.29 mg/mL). Considering mycobacterial inhibition, the best results were obtained by chloroform fraction against M. tuberculosis, M. smegmatis, and M. avium (MIC ranging from 156.25 to 625 µg/mL). This study proves, in part, that the popular use of C. ambrosioides L. can be an effective and sustainable alternative for the prevention and treatment of diseases caused by various infectious agents.

Chemical composition, antimicrobial and antioxidant potential of the essential oil of Guarea kunthiana A. Juss / Composição química, potencial antimicrobiano e antioxidante do óleo essencial de Guarea kunthiana A. Juss

Abstract The essential oils are extracted from plant compounds and can present activities antimicrobial and antioxidant properties. The goals of the present study were: (a) to determine the chemical composition of the essential oil of Guarea kunthiana A. Juss using the method of gas chromatography coupled to mass spectrometry (GC-MS); (b) to evaluate the antimicrobial potential of this oil using the broth microdilution method against different microorganisms: five Gram-negative bacteria, four Gram-positive bacteria and a yeast and (c) to determine the antioxidant activity of the oil using the DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical assay. The GC-MS analyses allowed identifying 13 constituents, representing 96.52% of the essencial oil composition. The main compounds identified were α-zingiberene (34.48%), β-sesquiphellandrene (22.90%), and α-curcumene (16.17%). With respect to the antimicrobial activity, the essential oil was effective against all the microorganisms tested, except for the bacteria E. coli and K. pneumoniae, which were resistant to the action of the oil. From a general point of view, Gram-positive bacteria were more susceptible to the action of the essential oil than Gram-negative bacteria. The essential oil exhibited antioxidant potential.

Resumo Os óleos essenciais são compostos extraídos de plantas e podem apresentar propriedades antimicrobianas e antioxidantes. O objetivo deste trabalho foi (a) determinar a composição química do óleo essencial de Guarea kunthiana A. Juss pelo método de cromatografia gasosa acoplada à espectrometria de massas (CG-EM); (b) avaliar o potencial antimicrobiano deste óleo pelo método de microdiluição em caldo frente a diferentes micro-organismos, sendo cinco bactérias Gram-negativas, quatro Gram-positivas uma levedura e (c) por fim, determinar a atividade antioxidante do óleo pelo método de captura do radical livre 2,2-difenil-1-picril hidrazil (DPPH). As análises de CG-EM resultaram na identificação de 13 constituintes, representando 96,52% da composição do óleo essencial. Os principais compostos identificados foram α-Zingibereno (34,48%), β-Sesquifelandreno (22,90%) e α-Curcumeno (16,17%). Em relação à atividade antimicrobiana, o óleo essencial foi efetivo frente a todos os micro-organismos testados exceto para as bactérias E. coli e K. pneumoniae, as quais se apresentaram resistentes à ação do óleo. Em geral, as bactérias Gram-positivas foram mais suscetíveis à ação do óleo essencial em relação às Gram-negativas. O óleo essencial apresentou potencial.

Effectiveness of omega-3 polyunsaturated fatty acids against microbial pathogens / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Microorganisms provide both beneficial and harmful effects to human beings. Beneficial effects come from the symbiotic relationship that exists between humans and microbiota, but then several human illnesses have turned some friendly microbes into opportunistic pathogens, causing several microbial-related diseases. Various efforts have been made to create and utilize antimicrobial agents in the treatment and prevention of these infections, but such efforts have been hampered by the emergence of antimicrobial resistance. Despite extensive studies on drug discovery to alleviate this problem, issues with the toxicity and tolerance of certain compounds and continuous microbial evolution have forced researchers to focus on screening various phytochemical dietary compounds for antimicrobial activity. Linolenic acid and its derivatives (eicosapentaenoic acid and docosahexaenoic acid) are omega-3 fatty acids that have been studied due to their role in human health, being important for the brain, the eye, the cardiovascular system, and general human growth. However, their utilization as antimicrobial agents has not been widely appreciated, perhaps due to a lack of understanding of antimicrobial mechanisms, toxicity, and route of administration. Therefore, this review focuses on the efficacy, mechanism, and toxicity of omega-3 fatty acids as alternative therapeutic agents for treating and preventing diseases associated with pathogenic microorganisms.

Antimicrobial potential of pyroligneous extracts - a systematic review and technological prospecting

Abstract Pyroligneous extract is applied in diverse areas as an antioxidant, an antimicrobial, and an anti-inflammatory agent. The discovery of new cost-effective antimicrobial agents of natural origin remains a challenge for the scientific community. This study aimed to conduct a systematic review and a technological forecasting of the existent evidence regarding the use of pyroligneous extract as a potential antimicrobial agent. Studies were identified through an investigation of various electronic databases: PubMed, SciFinder, Web of Science, Scopus, Scielo, Google scholar, and ProQuest. Patents were searched through INPI, Google patents, Espacenet, Patents online, USPTO, and WIPO. The literature on antimicrobial activity of pyroligneous extract are limited given the short duration of studies and variability in study design, use of pyroligneous preparations, and reports on results. However, evidence suggests the potential of pyroligneous extract as a natural antimicrobial agent. The most studied activity was the role of PE as a food preservative. However, pyroligneous extracts are also effective against pathogenic bacteria in the oral microflora and treatment of candidal infections. Further research is needed using standardized preparations of pyroligneous extracts to determine their long-term effectiveness and ability as antimicrobial agents.

Serum concentrations of acute phase proteins in goats and ewes with naturally acquired Staphylococcus aureus mastitis / Concentração de proteínas de fase aguda em cabras e ovelhas com mastite de ocorrência natural causada por Staphylococcus aureus

Serum protein concentrations, including acute phase proteins (APPs), of goats and ewes with naturally acquired Sthaphylococcus aureus mastitis were determined by means of SDS-PAGE electrophoresis to evaluate the relevance of these APPs as biomarkers of the disease in these species. Fifteen healthy goats and 5 goats with naturally acquired staphylococci mastitis, as well as fifteen healthy ewes and 5 ewes with staphylococci mastitis were submitted to daily blood sampling during 7 days. In goats, an increase of 570%, 125%, 621%, and 279% in serum concentrations of ceruloplasmin, fibrinogen, haptoglobin and α1-acid glycoprotein, respectively, was observed. In sheep the increase in serum concentrations of ceruloplasmin, fibrinogen, haptoglobin and α1-acid glycoprotein was of 337%, 90%, 461%, and 225%, respectively. Our results indicate that these APPs have considerable potencial as early and sensible biomarkers of mastitis caused by S. aureus in goats and sheep.(AU)

O proteinograma, incluindo proteínas de fase aguda (PFAs), de cabras e ovelhas com mastite de origem natural causada por Staphylococcus aureus, foi determinado por meio de eletroforese em gel de poliacrilamida contendo dodecil sulfato de sódio (SDS-PAGE) a fim de avaliar a importância destas PFAs como biomarcadores da enfermidade nestas espécies. Amostras de sangue foram colhidas diariamente de cinco cabras e cinco ovelhas com mastite estafilocócica naturalmente adquirida, bem como de quinze cabras e quinzes ovelhas saudáveis durante 6 dias consecutivos. Nas fêmeas caprinas, foi verificado aumento dos teores séricos de ceruloplasmina (570%), fibrinogênio (125%), haptoglobina (621%), e α1-glicoproteína ácida (279%). Nas fêmeas ovinas as concentrações de ceruloplasmina, fibrinogênio, haptoglobina e α1-glicoproteína ácida elevaram-se em 337%, 90,9%, 461% e 225%, respectivamente. Os resultados permitem inferir que estas PFAs são marcadores sensíveis e precoces de mastite causada por S. aureus em cabras e ovelhas.(AU)

In vitro activity of linezolid in combination with photodynamic inactivation against Staphylococcus aureus biofilms

Background: Biofilm infections are a major challenge in medical practice. Bacteria that live in a biofilm phenotype are more resistant to both antimicrobial therapy and host immune responses compared to their planktonic counterparts. So, there is need for new therapeutic strategies to combat these infections. A promising approach [known as Photodynamic Inactivation [PDI]] to kill bacteria growing as biofilms uses light in combination with a photosensitizer to induce a phototoxic reaction which produces reactive oxygen species that can destroy lipids and proteins causing cell death. PDI does not always guarantee full success, so, combination of PDI with antibiotics may give increased efficiency. This study aimed to determine if PDI was effective in the eradication of Staphylococcus aureus [S. aureus] biofilms in combination with linezolid

Methods: The susceptibility of biofilm cultures of three S. aureus strains to Methylene Blue [MB] and Toluidine Blue O [TBO]-mediated PDI was determined alone and in combination with linezolid

Results: Bactericidal activity [>/=3 log[10] reduction in viable cell count] was not achieved with MB/TBO-PDI or antibiotic treatment alone. When antibiotic treatment was combined with TBO-PDI, a greater reduction in viable count than antibiotic alone was observed for two strains

Conclusion: This study showed that although TBO-PDI did not have good bactericidal activity against S. aureus biofilms; it increased the antimicrobial activity of linezolid against these bacteria

In vitro analysis of a local polymeric device as an alternative for systemic antibiotics in Dentistry

Abstract The development of a biodegradable material with antimicrobial properties for local applications is required in the prevention and treatment of infectious diseases. The objective of this study was to produce blends of poly-L-lactide acid (PLLA) synthetic polymer associated with several antimicrobials, as an alternative in the prevention and treatment of infections, as well as to evaluate its cytotoxicity, release of antimicrobials and inhibit bacteria growth. Blends of PLLA added with 20% Amoxicillin, Metronidazole, Clindamycin or Azithromicyn were used to produce Films (F) or Meshs (M) by casting and electrospinning methods, respectively. Standardized discs of the films and meshs were stored in buffer solutions (pH 5 or 7.4) and aliquots were analyzed by high performance chromatography (HPLC) during 168 hours. Cytotoxicity on human gingival fibroblasts was tested after 24, 48 and 72h by MTT reaction. The antimicrobial capacity was determined against P. gingivalis and S. pyogenes. The specimens were weighed after 3 and 6 months of storage for degradation analysis. SEM was performed to control interfaces and degradation. Antimicrobials presented a continuous and exponential drug release. Analysis showed that both M and F were able to inhibit S. pyogenes and P. gingivalis growth, indicating the release of active antimicrobial agents. The products were not toxic to the fibroblasts. Amoxicillin-film showed more degradation than PLLA at both pHs (p < 0.05), whereas Azithromycin-meshes were more degraded than PLLA at pH 7.4 (p < 0.05). PLLA association with antimicrobials is biocompatible and may represent a potential tool for the local delivery of antimicrobials.

Antimicrobial profile of Arthrobacter kerguelensis VL-RK_09 isolated from Mango orchards

Abstract An actinobacterial strain VL-RK_09 having potential antimicrobial activities was isolated from a mango orchard in Krishna District, Andhra Pradesh (India) and was identified as Arthrobacter kerguelensis. The strain A. kerguelensis VL-RK_09 exhibited a broad spectrum of in vitro antimicrobial activity against bacteria and fungi. Production of bioactive metabolites by the strain was the highest in modified yeast extract malt extract dextrose broth, as compared to other media tested. Lactose (1%) and peptone (0.5%) were found to be the most suitable carbon and nitrogen sources, respectively, for the optimum production of the bioactive metabolites. The maximum production of the bioactive metabolites was detected in the culture medium with an initial pH of 7, in which the strain was incubated for five days at 30 °C under shaking conditions. Screening of secondary metabolites obtained from the culture broth led to the isolation of a compound active against a wide variety of Gram-positive and negative bacteria and fungi. The structure of the first active fraction was elucidated using Fourier transform infrared spectroscopy, electrospray ionization mass spectrometry, 1H and 13C nuclear magnetic resonance spectroscopy. The compound was identified as S,S-dipropyl carbonodithioate. This study is the first report of the occurrence of this compound in the genus Arthrobacter.

Synergistic Anti-bacterial Effects of Phellinus baumii Ethyl Acetate Extracts and beta-Lactam Antimicrobial Agents Against Methicillin-Resistant Staphylococcus aureus

BACKGROUND: The development of new drugs or alternative therapies effective against methicillin-resistant Staphylococcus aureus (MRSA) is of great importance, and various natural anti-MRSA products are good candidates for combination therapies. We evaluated the antibacterial activities of a Phellinus baumii ethyl acetate extract (PBEAE) and its synergistic effects with beta-lactams against MRSA. METHODS: The broth microdilution method was used to determine the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of the PBEAE. The PBEAE synergistic effects were determined by evaluating the MICs of anti-staphylococcal antibiotic mixtures, with or without PBEAE. Anti-MRSA synergistic bactericidal effects of the PBEAE and beta-lactams were assessed by time-killing assay. An ELISA was used to determine the effect of the PBEAE on penicillin binding protein (PBP)2a production. RESULTS: The MICs and MBCs of PBEAE against MRSA were 256-512 and 1,024-2,048 microg/mL, respectively. The PBEAE significantly reduced MICs of all beta-lactams tested, including oxacillin, cefazolin, cefepime, and penicillin. However, the PBEAE had little or no effect on the activity of non-beta-lactams. Time-killing assays showed that the synergistic effects of two beta-lactams (oxacillin and cefazolin) with the PBEAE were bactericidal in nature (Deltalog10 colony forming unit/mL at 24 hr: 2.34-2.87 and 2.10-3.04, respectively). The PBEAE induced a dose-dependent decrease in PBP2a production by MRSA, suggesting that the inhibition of PBP2a production was a major synergistic mechanism between the beta-lactams and the PBEAE. CONCLUSIONS: PBEAE can enhance the efficacy of beta-lactams for combined therapy in patients infected with MRSA.

Synthesis and antimicrobial evaluation of two peptide LyeTx I derivatives modified with the chelating agent HYNIC for radiolabeling with technetium-99m

Current diagnostic methods and imaging techniques are not able to differentiate septic and aseptic inflammation. Thus, reliable methods are sought to provide this distinction and scintigraphic imaging is an interesting option, since it is based on physiological changes. In this context, radiolabeled antimicrobial peptides have been investigated as they accumulate in infectious sites instead of aseptic inflammation. The peptide LyeTx I, from the venom of Lycosa erythrognatha, has potent antimicrobial activity. Therefore, this study aimed to synthesize LyeTx I derivatives with the chelating compound HYNIC, to evaluate their antimicrobial activity and to radiolabel them with 99mTc. Methods Two LyeTx I derivatives, HYNIC-LyeTx I (N-terminal modification) and LyeTx I-K-HYNIC (C-terminal modification), were synthesized by Fmoc strategy and purified by RP-HPLC. The purified products were assessed by RP-HPLC and MALDI-ToF-MS analysis. Microbiological assays were performed against S. aureus (ATCC® 6538) and E. coli (ATCC® 10536) in liquid medium to calculate the MIC. The radiolabeling procedure of LyeTx I-K-HYNIC with 99mTc was performed in the presence of co-ligands (tricine and EDDA) and reducing agent (SnCl2. 2H2O), and standardized taking into account the amount of peptide, reducing agent, pH and heating. Radiochemical purity analysis was performed by thin-layer chromatography on silica gel strips and the radiolabeled compound was assessed by RP-HPLC and radioactivity measurement of the collected fractions. Data were analyzed by ANOVA, followed by Tukey test (p-values 0.05). Results Both LyeTx I derivatives were suitably synthesized and purified, as shown by RP-HPLC and MALDI-ToF-MS analysis. The microbiological test showed that HYNIC-LyeTx I (N-terminal modification) did not inhibit bacterial growth, whereas LyeTx I-K-HYNIC (C-terminal modification) showed a MIC of 5.05 mol.L1 (S. aureus) and 10.10 mol.L1 (E. coli). Thus, only the latter was radiolabeled with 99mTc. The radiochemical purity analysis of LyeTx I-K-HYNIC-99mTc showed that the optimal radiolabeling conditions (10 g of LyeTx I-K-HYNIC; 250 g of SnCl2. 2H2O; pH = 7; heating for 15 min) yielded a radiochemical purity of 87 ± 1 % (n= 3). However, RP-HPLC data suggested 99mTc transchelation from LyeTx I-K-HYNIC to the co-ligands (tricine and EDDA). Conclusions The binding of HYNIC to the N-terminal portion of LyeTx I seems to affect its activity against bacteria. Nevertheless, the radiolabeling of the C-terminal derivative, LyeTx I-K-HYNIC, must be better investigated to optimize the radiolabeled compound, in order to use it as a specific imaging agent to distinguish septic and aseptic inflammation.

Analysis of the reaction of subcutaneous tissues in rats and the antimicrobial activity of calcium hydroxide paste used in association with different substances

The aim of this study was to evaluate the subcutaneous tissue response in rats and the antimicrobial activity of intracanal calcium hydroxide dressings mixed with different substances against E. faecalis. Fifty four rats were divided into three experimental groups according to the vehicle in the calcium hydroxide treatment: 0.4% chlorohexidine in propylene glycol (PG),Casearia sylvestris Sw in PG and calcium hydroxide+PG (control group). The pastes were placed into polyethylene tubes and implanted into the subcutaneous tissue. After 7, 14 and 30 days, the samples were processed and histologically evaluated (hematoxylin and eosin). The tissue surface in contact with the material was analyzed, and the quantitative analysis determined the volume density occupied by the inflammatory infiltrate (giant cells, polymorphonuclear cells and mononuclear cells), fibroblasts, collagen fibers and blood vessels. For the antimicrobial analysis, 20 dentin blocks infected with E. faecalis were treated with calcium hydroxide pastes in different vehicles; 0.4% chlorhexidine in PG, PG, extract fromCasearia sylvestris Sw in PG and a positive control (infection and without medication) for 7 days. The efficiency of the pastes was evaluated by the live/dead technique and confocal microscopy. The results showed that 0.4% chlorhexidine induced a higher inflammatory response than the other groups. The Casearia sylvestris Sw extract showed satisfactory results in relation to the intensity of the inflammatory response. In the microbiological test, there were no statistical differences between the evaluated intracanal dressings and the percentage of bacterial viability was between 33 and 42%. The control group showed an 86% viability. Antimicrobial components such as chlorhexidine or Casearia sylvestris Sw did not improve the antimicrobial activity against E. faecalis in comparison to the calcium hydroxide+PG treatment. In addition, the incorporation of chlorhexidine in the calcium hydroxide paste promoted the highest inflammatory response.