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Background: The Clove (Syzygium aromaticum), a member of the Myrtaceae family, is cultivated in various countries across Asia, Africa, and the West. Eugenol, its primary volatile phenolic compound, imparts characteristic aroma and flavor, as well as possessing bactericidal properties. Objective: This study evaluated the antibacterial activity of clove essential oil (Syzygium aromaticum) against Escherichia coli, Pseudomonas aeruginosa, and Salmonella spp, isolated from food and water. Methods: To achieve this, the essential oil was extracted from the dried floral buds of cloves using the hydrodistillation method, using a Clevenger system. The susceptibility assessment of the strains took place using the disc diffusion method. Results: Escherichia coli and Salmonella, isolated from food, demonstrated sensitivity to the essential oil, with inhibition halos of 16 and 18 mm, respectively. The gram-negative strains Salmonella spp. and Salmonella isolated from sururu (Mytella guyanensis) were also sensitive to the oil, and the pattern with inhibition halos was 15 mm. However, strains of Pseudomonas aeruginosa, isolated from water, did not show activity against the essential oil. Discussion: The essential oil extracted from Syzygium aromaticum, known as clove, demonstrated a high level of antibacterial activity against two of the three tested bacterial strains (Escherichia coli and Salmonella spp), while exhibiting moderately effective activity against Pseudomonas aeruginosa. Conclusions: The microbiological study revealed that clove essential oil exhibited good antibacterial activity against the tested strains, with eugenol being the main compound responsible for this efficacy. [ABSTRACT FROM AUTHOR]

Este estudo teve como objetivo avaliar a atividade antibacteriana in vitro do extrato aquoso de Baccharis dracunculifolia e Tamarindus indica L., dos extratos naturais líquidos da casca da castanha de caju (LCC) e do óleo essencial (OE) de cravo contra cinco espécies de bactérias ruminais Gram-negativas. As culturas foram cultivadas em meio anaeróbio contendo 0,1, 0,2, 0,5 e 1,0 mg mL-1 dos extratos ou óleos. O crescimento foi avaliado monitorando a densidade óptica (DO 600 nm) em intervalos de 0, 8, 12 e 24 horas de incubação a 39° C. O extrato aquoso de baccharis e tamarindo e o extrato natural de LCC inibiram o crescimento de Prevotella albensis, Prevotella bryantii, Treponema saccharophilum e Succinivibrio dextrinosolvens. Para Prevotella ruminicola e Succinivibrio dextrinosolvens, a adição de 1,0 mg mL-1 de OE de folhas de cravo resultou em maior impacto na dinâmica de crescimento, com redução na densidade óptica em todos os intervalos de observações. Os resultados desta pesquisa estabelecem a eficácia dos aditivos naturais extratos aquosos de baccharis e tamarindo, LCC e óleo essencial de cravo, na atividade antimicrobiana in vitro contra as bactérias ruminais Gram-negativas analisadas.

The purpose of the study was to investigate the antibacterial capacity of silver nanoparticles (AgNPs), biosynthesized with extracts of queñua (Polylepis racemosa), in the influent of the wastewater treatment plant (WWTP) of the department of Cusco, Peru. The queñua extracts were prepared by maceration, using distilled water and a 50% hydroethanolic mixture as solvents. The biosynthesis was carried out by mixing 0.1 M AgNO3 with the prepared extracts, then the effect of the biosynthesis pH, temperature, and the percentage of ethanol concentration on the size of the AgNPs was studied. The results revealed that the optimal conditions to obtain hydrodynamic sizes of 58.68 nm and stable after 11 weeks of biosynthesis were when aqueous extract was used with pH of 10 and a temperature of 20 ºC. The antibacterial activity of the AgNPs was evaluated in 500 mL of wastewater with an initial load 33 × 106 NMP/100 mL of total and thermotolerant coliforms, the findings indicated that the doses of AgNPs eradicated almost 100% of these contaminants, suggesting that AgNPs are a potential antibacterial agent. [ABSTRACT FROM AUTHOR]

Introduction: Lichens are complex organisms conformed by a symbiotic association between algae and fungi; they are haven considerable interest owing to their pharmacological properties. Objectives: To determine chemical composition of the fatty acid (FA) and the percentage of usnic acid (UA), and to evaluate the in vitro antibacterial activity of the ethanolic extract obtained from the lichens Usnea sp., Thamnolia vermicularis subsp. solida and Ramalina asperula. Materials and Methods: Organic extracts from the three lichens were obtained using a rotary evaporator, soxhlet extractor and ultrasound equipment. The chemical composition of FA was determined by gas chromatography-flame ionisation detector, and the percentage of UA was quantified by UV-Vis spectroscopy. The in vitro antibacterial activity of the lichen ethanolic extracts was evaluated against E. coli ATCC 25922, Bacillus subtilis ATCC 11774, Staphylococcus aureus ATCC 43300 and S. aureus ATCC 29213 using the diffusion and microdilution methods. The minimum inhibitory concentration (MIC) was determined. Results: In the three tested lichens, the identified FAs were palmitic, stearic, oleic, linoleic, and linolenic acids; and the obtained percentage of UA was between 0.2 and 1.07 %. All the ethanolic extracts obtained from three lichens showed a high activity against B. subtilis (MIC = 0.5 mg/mL), while the ethanolic extracts obtained from T. vermicularis subsp. solida and R. asperula showed moderate activity against S. aureus ATCC 43300 (MIC = 3 and 1 mg/mL) and S. aureus ATCC29213 (MIC = 4 and 1 mg/mL). Conclusions: Our findings found for the three studied lichens confirmed the presence of some FAs and AU. These species provide an acceptable nutritional content and besides they can be considered as potential antibacterial agents. [ABSTRACT FROM AUTHOR]

Introduction: bacterial infections have become a major challenge in healthcare due to the emergence and spread of multidrug-resistant bacteria, which has led to increased interest in the development of new antimicrobial agents. Objective: to investigate the antibacterial potential of cinnamaldehyde against Staphylococcus aureus and Klebsiella pneumoniae as well as to study the interactions of this phytochemical with ATP synthase and FtsZ through molecular docking. Methodology: in the in vitro assays, the microdilution technique was applied in 96-well plates to obtain the minimum inhibitory and bactericidal concentration (MIC and MBC). For the in silico assays, the procedure adopted was that of molecular anchoring with the rigid protein (ATP synthase and FtsZ) and the flexible ligand. Results: it was found a strong antibacterial activity against S. aureus and K. pneumoniae of cinnamaldehyde with MIC = 64 and 32 µg/mL respectively and CBM = 128 and 64 µg/mL respectively, with better spectrum of action against Gram negative bacteria. Furthermore, cinnamaldehyde was able to bind ATP synthase and FtsZ with energies of ΔE = -5.10 kcal/mol and ΔE = -5.20 kcal/mol respectively. Conclusion: Cinnamaldehyde has a bactericidal effect against S. aureus and K. pneumoniae and this effect is predictive because of the interactions of this phytochemical with ATP synthase and FtsZ. [ABSTRACT FROM AUTHOR]

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Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Introduction: Bacteria are unicellular and prokaryotic organisms that can be a cause of disease and one of the main causes of death in many countries. The constant development and increase of resistant bacteria poses a threat to public health, which leads to an urgent need for new compounds with antimicrobial action, in which natural products with great potential for possible antibacterial agents, such as terpenes, stand out. Aim: To carry out a systematic review to evaluate the therapeutic potential of R-(+)-Limonene against pathogenic bacteria. Methodology: The research focused on documents written in English and Portuguese published between 2011 and 2021. Data were collected from the literature available in CAPES electronic journals, using three databases: Embase, Pubmed and Web of Science. The organization of studies and their management until the end of writing was carried out with the help of Mendeley software. Results: Initially 1367 articles were identified, after refinement of the search, culminating in 15 articles elected for the construction of the review, in which R-(+)-Limonene both in its isolated form and associated with another compound showed antibacterial effect against strains bacteria, both gram positive and gram negative. Conclusion: the terpene R-(+)-Limonene can be considered as a promising substance to fight diseases caused by pathogenic bacteria. However, more studies are needed to deepen the mechanism of action, as well as, against more bacterial species isolated from different origins, in order to more effectively understand this biological effect found. [ABSTRACT FROM AUTHOR]

Atualmente, aumentaram as pesquisas com extratos de plantas buscando a ação terapêutica no controle de doenças da cavidade bucal, especialmente a cárie dental. Diversos extratos vegetais já são incorporados nos dentifrícios e enxaguantes bucais. O objetivo deste estudo foi avaliar in vitro a ação antibacteriana dos extratos de Psidium guajava (goiabeira), Phalaenopsis sp. (orquídea), Syzygium aromaticum (cravo-da-Índia) e Cinnamomum verum (canela-do-Ceilão). Os testes foram realizados com a bactéria da cavidade bucal Streptococcus mutans. A atividade antibacteriana dos extratos vegetais foi avaliada por método de disco difusão em ágar e por concentração inibitória mínima (CIM). Os testes mostraram a eficácia dos extratos por meio de zonas de inibição do crescimento bacteriano (de 5 a 20 mm de diâmetro) e CIM de 100 mg. mL-1 extrato da Phalaenopsis sp. e de 50 mg. mL-1 extrato da P. guajava. Estudos complementares serão necessários para avaliar outras ações farmacológicas na finalidade de usar estes extratos vegetais nas diferentes especialidades odontológicas e principalmente no tratamento e profilaxia da cárie dental.

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Propolis has been considered a resinous substance with a complex chemical composition that is collected from several plant species by Apis mellifera bees, and used by man as an alternative to the healing of diseases and to keep a good health. The chemical composition of propolis is related to the biodiversity of the region visited by the bees and also to the season of collection. This research purpose was to optimize the production methodology of propolis' ethanol extract production and to evaluate the effect of seasonality in the chemical composition and biological activities of this product. Propolis' samples were collected from the apiary at the Instituto Federal de Educação, Ciência e Tecnologia do Sul de Minas Gerais - Campus Muzambinho and were used to make ethanol extracts. In the optimization stage, different ethanolic solution concentration, extraction method and drying temperatures were used. For the analysis of the seasonal effect, propolis was collected from the same place in different seasons. The results showed that the 80% ethanolic solution, the extraction temperature of 70&#176:C and drying at 45&#176:C were the ones that stood out the most. Regarding the effect of seasonality on the chemical composition and biological activities of propolis, it is clear that there are differences between the propolis collected in different seasons. [ABSTRACT FROM AUTHOR]

Aim:to carry out a bibliographic review on the antimicrobial potential of carveol. It is an integrative review between the years 2010-2020 in the BVS, PubMed, SciELO, Science-Direct and Web of Science databases. Methodology: of the 2753 articles retrieved from the databases, only 5 were selected to compose the results, the most studied genera being Candida, Staphylococcus and Escherichia. The broth microdilution technique was the most widely used methodology to determine its action. In terms of MIC, for most species, they were excellent. Regarding the Time-kill test, carveol had an excellent performance at a concentration of 4 x MIC, which showed a reduction of CFU by 6 log in 2 hours. No studies have been found in the literature on the use of the Checkboard method. Furthermore, this compound had good antibiofilm activity against Staphylococcus aureus bacteria. Results: the possible mechanism of action of the antimicrobial activity of carveol occurs through the severe damage caused to the cytoplasmic membranes, which will favor cell lysis. Thus, there are few studies in the available scientific collection that address the subject, so it is necessary to carry out more in vitro and in vivo studies to better elucidate its action. [ABSTRACT FROM AUTHOR]

Introduction: biofilm-related infections caused by Staphylococcus aureus, Klebsiella pneumoniae and Pseudomonas aeruginosa are difficult to treat and few effective pharmacological options are currently available for this purpose. In this context, coumarin (2H-1-Benzopyran-2-one) has been reported to have antibacterial and antibiofilm activity, but this potential remains poorly understood. Aim: to investigate the action of coumarin on planktonic and biofilm forms of S. aureus, K. pneumoniae and P. aeruginosa. Results: a minimum inhibitory concentration (MIC) of coumarin ranging from 256 to 1024 µg/mL was observed, with a remarkable ability to inhibit the formation of biofilms and to act on mature biofilms in concentrations close to MIC. Conclusion: coumarin has strong activity against planktonic and biofilm forms on the three species of great relevance in the clinical scenario. These results are interesting to enable a pharmacological alternative for the treatment of these infections. [ABSTRACT FROM AUTHOR]

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Miconia albicans (Sw.) Triana é um arbusto com ramos caulinares esfoliativos; lâmina coriácea, face adaxial glabrescente, verde-escuro, abaxial albo-ferruginosa; flores brancas; fruto tipo baga. É utilizada para infecções urinárias, genitais e para reumatismo. Objetivou-se realizar a descrição morfo-anatômica, triagem fitoquímica, atividade antimicrobiana do extrato bruto e de frações das folhas. O material vegetal foi coletado em Pirenópolis, pulverizado e submetido à triagem fitoquímica. A avaliação da atividade antimicrobiana foi determinada através da Concentração Inibitória Mínima. Verificou-se a presença de cumarinas, triterpenos, taninos, desoxiaçúcares, flavonóides e saponinas no pó das folhas. Foi verificada atividade antimicrobiana do extrato etanólico bruto frente a Listeria innocua, da fração acetato de etila contra Bacillus cereus, Listeria innocua, Listeria monocytogenes e da fração hexano contra Listeria monocytogenes. O presente estudo fornece subsídios para geração de produtos que possam ser utilizados como conservantes e/ ou para o controle do crescimento microbiano em alimentos.

Os venenos de serpentes são reconhecidos como uma fonte promissora de substâncias farmacologicamente ativas e potencialmente úteis para o desenvolvimento de novas drogas antimicrobianas. Esse trabalho teve como objetivo investigar a atividade antimicrobiana do veneno de Crotalus durissus terrificus contra várias bactérias. A determinação da atividade antibacteriana foi realizada pelo método de microdiluição em placas e a ação na estrutura do envelope bacteriano pelo ensaio violeta de cristal. As proteínas do extrato bruto foram separadas por eletroforese e caracterizadas quanto à sua atividade proteolítica. O veneno de C. d. terrificus apresentou ação antimicrobiana frente bactérias gram-positivas e gram-negativas. Os valores de MIC foram definidos para Pseudomonas aeruginosa ATCC 27853 (62.5 μg/ mL), Staphylococcus aureus ATCC 25923 (125 μg/mL) e Micrococcus luteus ATCC 9341 (≤ 500 μg/mL). Para Salmonella enterica serovar typhimurium ATCC 14028 e Corynebacterium glutamicum ATCC 13032, o decréscimo no crescimento bacteriano não foi detectado visualmente, mas foi estatisticamente significante. O teste do cristal violeta demonstrou que o veneno bruto aumentou a permeabilidade das células bacterianas e o perfil de proteína secretada está em consonância com relatos anteriores. Os resultados sugerem que as proteínas com atividade lítica contra bactérias no veneno de C. d. terrificus merecem atenção para uma melhor caracterização, uma vez que podem trazer reforços para o escasso arsenal terapêutico empregado para combater a multirresistência microbiana.Palavras-chave: veneno de cascavel, ação antimicrobiana, envelope celular, atividade proteolítica.

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Bacterial resistance is a growing challenge facing drug design scientists to find new medications or update commonly used antibiotics. The objective of this study was to synthesize, structure and highlight biological features of new species of metal-organic complexes [(MCl2)2L1] {M = Ni, Cu, L1 = N,N'-1,4- Phenylenebis(methanylylidene)bis(ethane-1,2-diamine)} and [(NiCl2)2L2]. The Schiff base ligands were prepared in an excellent yeilds by adding terephthalaldehyde to 1,2-ethane-diamine or 1,4-butane-diamine. Three binuclear Schiff base metal complexes were synthesized in a simple one-pot reaction by reacting the corresponding metal chloride (NiCl2 and CuCl2) salts with the Schiff base ligands {L1 = N,N'-(1,4- phenylenebis(methanylylidene)bis(1,2-diethylamine)) and L2 = N,N'-(1,4- phenylenebis(methanylylidene)bis(butane-1,4-diamine))}. The obtained Schiff base metal complexes were analytically, characterized by a set of spectroscopic techniques such as FT-IR spectroscopy, 1H NMR spectra, and mass spectra. The structures characterization studies suggest that Schiff base ligands behave as N bidentate ligands for nickel and copper metal centers, which are known to act as Lewis acids. The biological activity of the Schiff base of nickel(II) and copper(II) complexes was tested by using the broth dilution method. The complexes showed antibacterial activity against all gram-negative and gram-positive bacteria (Enterobacter cloacae G-, Citrobacter G-, Pseudomonas G-, Klebsiella G-, Staphylococcus G+, and Streptococcus G+) that used in the trials. It is concluded that Schiff base metal complexes are a good candidate for the antibacterial drug because of its good activity against gram-negative and gram-positive strains demonstrated in the present study, as well as in other studies in the literature. [ABSTRACT FROM AUTHOR]

Metals that contain nanomaterials have the potential to be employed in controlling different kinds of infection, however, very limited information is known about their antibacterial properties. This study has been done to investigate the nanosynthesis titanium nanoparticles (TiNPs) using Streptococcus thermophilus and analyzing their biological actions as antibacterial. The bacterial isolates identified using universal primers 16S rRNA; then the 16S rRNA gene nucleotide sequences were aligned with the nucleotide sequences of strains obtained from the GeneBank through the software CLUSTAL X (version 1.82). Titanium nanoparticles were nanosynthesized by adding 0.025M titanium dioxide (TiO2) into cell-free supernatant for Streptococcus thermophilus. TiO2 was used as a precursor for nanobiosynthesis TiNPs. The formation of TiNPs was indicated by the color alteration of the solution from the light brown into dark brown indicates for the production of TiNPs. The Characterization of nanobiosynthesis was accomplished with UV-Visible (absorbance at 377nm), Scanning Electron Microscope, X-ray diffraction, Atomic Force Microscope, Energy-dispersive X-ray spectroscopy was used to distinguish the dimension, form (spherical) by SEM, dispersal (homogenous) and elemental analysis of nanoparticles. Biogenic TiNPs have displayed antibacterial and antibiofilm activity against both multidrugresistant Klebsiella pneumonia and Staphylococcus aureus. As an antibacterial activity, the TiNPs inhibited significantly K.pneumoniae (20 mm) with concentration (500 μg/ml), and S. aureus (16 mm) with the same concentration and increasing the concentration of TiNPs the inhibition zone increased. While as antibiofilm activity of TiNPs using the tube method, the tubes containing bacterial suspension K.pneumoniae and S.aureus with TiNPs, the results demonstrated that the biofilm formation was prevented and removed by the effect of TiNPs. [ABSTRACT FROM AUTHOR]

ABSTRACT: The use of natural products, such as essential oils (EOs), is a potential novel approach to treat fish bacterial infections with a lower risk of developing resistance. There has been a number of studies reporting the activity of EOs as those obtained from the species Achyrocline satureioides, Aniba parviflora, Aniba rosaeodora, Anthemis nobilis, Conobea scoparioides, Cupressus sempervirens, Illicium verum, Lippia origanoides, and Melaleuca alternifolia against bacteria. However, there are few studies investigating the effect of these EOs against fish bacteria. Therefore, the aim of this study was to evaluate the in vitro antibacterial activity of EOs against the following fish bacteria, Aeromonas hydrophila, Citrobacter freundii, and Raoultella ornithinolytica. Additionally, the in vivo antibacterial activity of the EO L. origanoides was evaluated against experimentally induced A. hydrophila infection of silver catfish (Rhamdia quelen). The EO of L. origanoides was chosen as it showed the highest in vitro antibacterial activity, with minimum inhibitory concentrations ranging from 0.2 to 0.8 mg mL-1. This EO also presented a therapeutic success of 58.33%, on a 30 day A. hydrophila infection. Therefore, we suggested that the EO of L. origanoides may be a viable alternative as a treatment for A. hydrophila infection.

Copyright of Implant Dentistry is the property of Lippincott Williams & Wilkins and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The present work describes the qualitativequantitative chemical characterization of essential oils (EO) present in the leaves of Mangifera indica L. which were collected in the states of Mérida (M), Barinas (B), and Portuguese (P), in the Bolivarian Republic of Venezuela, using the technique of hydrodistillation, coupled to the trap of Clevenger. Volumes of 0.1 mL (0.0025%), 1.4 mL (0.035%) and 1.0 mL (0.025%) were obtained, respectively. The essential oils were characterized by the method of gas chromatography coupled to mass spectrometry (GC/MS). 30 compounds in the sample collected in M, 24 in B and 14 in P were identified, being the majority in the M: ß-selinene (22,56%), a-gurjunene (14,66%) and ß-caryophyllene (10 40%); en B: ß-caryophyllene (36,32%), a-humulene (22,71%) and a-gurjunene (21,43%); and in P: ß-caryophyllene (36.07%), a-gurjunene (22.55%) and a-humulene (21.24%). Due to the low yield, the antibacterial activity was determined in the EO of B and P, by the agar diffusion method with disks, by various international reference bacteria (Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 23357, Pseudomonas aureginosa ATCC 27853). Both AE inhibited the development of S. aureus and E. faecalis with a minimum inhibitory concentration of 200 µL/mL and 300 µL/mL, respectively. This is the first comparative study and antibacterial activity of the essential oil obtained from the leaves of M. indica L. in three regions in the Bolivarian Republic of Venezuela. [ABSTRACT FROM AUTHOR]

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The use of natural products, such as essential oils (EOs), is a potential novel approach to treat fish bacterial infections with a lower risk of developing resistance. There has been a number of studies reporting the activity of EOs as those obtained from the species Achyrocline satureioides, Aniba parviflora, Aniba rosaeodora, Anthemis nobilis, Conobea scoparioides, Cupressus sempervirens, Illicium verum, Lippia origanoides, and Melaleuca alternifolia against bacteria. However, there are few studies investigating the effect of these EOs against fish bacteria. Therefore, the aim of this study was to evaluate the in vitro antibacterial activity of EOs against the following fish bacteria, Aeromonas hydrophila, Citrobacter freundii, and Raoultella ornithinolytica. Additionally, the in vivo antibacterial activity of the EO L. origanoides was evaluated against experimentally induced A. hydrophila infection of silver catfish (Rhamdia quelen). The EO of L. origanoides was chosen as it showed the highest in vitro antibacterial activity, with minimum inhibitory concentrations ranging from 0.2 to 0.8 mg mL-1. This EO also presented a therapeutic success of 58.33%, on a 30 day A. hydrophila infection. Therefore, we suggested that the EO of L. origanoides may be a viable alternative as a treatment for A. hydrophila infection. [ABSTRACT FROM AUTHOR]

In the present study, we report the synthesis and characterization of magnetite/silver magnetic nanoparticles (Fe3O4/Ag) and the study of their antibacterial properties against the bacteria Enterobacter aerogenes (Gramnegative) and Enterococcus faecalis (Grampositive). Magnetite magnetic nanoparticles (MNPs) were prepared by a sol-gel method using cetyltrimethylammonium bromide (CTAB), as a surfactant, followed by in-situ chemical reduction of silver ions by glucose, and polyvinylpyrrolidone (PVP), as a dispersive agent, to obtain the antibacterial nanocomposite of Fe3O4/Ag. Morphological and spectroscopic studies of magnetite nanoparticles and nanocomposite were carried out using the Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, Mössbauer spectroscopy (MS), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). Spherical Fe3O4 MNPs showed an average diameter of 10 nm and the average size for nanocomposite was 28 nm. The antibacterial test indicated that the use of the nanocomposite of Fe3O4/Ag at a concentration of 5 mg·mL-1 allowed a total inhibition of the growth of the microorganisms studied from an initial concentration of 108 bacteria mL-1. [ABSTRACT FROM AUTHOR]

Resumo Objetivou-se avaliar a atividade antibacteriana in vitro da própolis marrom, por meio da determinação da Concentração Inibitória Mínima (CIM). O extrato alcoólico de própolis foi obtido de 35 g de própolis bruta macerada em 65 mL de álcool de cereais. As concentrações do extrato de própolis usadas foram: 75mg/mL; 56,4mg/mL; 37,5mg/mL; 18,9mg/mL; 9,3mg/mL; 4,5mg/mL e 2,25mg/mL. Foram utilizados 32 isolados de bactérias Gram-positivas: Rhodococcus equi, Staphylococcus aureus, Staphylococcus hyicus, Staphylococcus spp. e Streptococcus spp., e 32 isolados de bactérias Gram-negativas: Enterobacter agglomerans, Escherichia coli, Klebsiella pneumoniae, Klebsiella sp., Pseudomonas aeruginosa, Pseudomonas spp., Salmonella spp. e Serratia rubidaea, provenientes de processos clínicos infecciosos de animais domésticos, obtidas e armazenadas no Laboratório de Bacteriologia da FAMEZ/UFMS. O extrato de própolis marrom apresentou atividade antimicrobiana com CIM variando de 2,25 a 18,9mg/mL para as bactérias Gram-positivas e 4,5 a 18,9mg/mL para as bactérias Gram-negativas, sendo as bactérias provenientes de bovinos e caninos as mais resistentes. Conclui-se que a própolis marrom tem ação bactericida, em função da espécie da bactéria e da procedência animal.

RESUMO O presente estudo teve como objetivo avaliar a atividade antibacteriana, antioxidante e citotóxica da espécie Opuntia cochenillifera (L.) Mill. Foi realizada a prospecção fitoquímica e espectroscopia de absorção de infravermelho (IV) dos extratos etanólicos brutos e frações dos cladódios grande e pequeno. A atividade antioxidante foi avaliada pelo método da capacidade sequestradora de radicais livres utilizando o radical sintético 2,2-difenil-1-picrilhidrazila (DPPH). A atividade citotóxica foi obtida através do método colorimétrico do Metiltetrazolium (MTT). Já a atividade antibacteriana foi avaliada pelo método de microdiluição em caldo para determinar a concentração inibitória mínima (CIM) frente às estirpes bacterianas Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa e Escherichia coli. A prospecção fitoquímica revelou principalmente a presença de fenóis, esteroides livres, alcaloides, alcanos, além de outras classes químicas. O IV apresentou grupos funcionais como alcanos, carbonilas, grupos de metila, duplas ligações de carbono, grupamentos alquilamina, entre outros. Sobre a citotoxicidade na concentração de 100 μg/mL, os dois extratos brutos, todas as frações do cladódio grande e as frações de clorofórmio e metanol do cladódio pequeno não apresentaram toxicidade. Os extratos brutos e frações do cladódio grande e pequeno, não demonstraram atividade antibacteriana e nem antioxidante. Esses resultados podem fornecer suporte para pesquisas futuras, visando outras atividades biológicas da presente espécie vegetal.

Abstract The study aimed to evaluate the antimicrobial activity, antioxidant, toxicity and phytochemical screening of the Red Propolis Alagoas. Antimicrobial activity was evaluated by disk diffusion method. Determination of antioxidant activity was performed using the DPPH assay (1.1-diphenyl-2-picrylhydrazyl), FTC (ferric thiocyanate) and determination of phenolic compounds by Follin method. Toxicity was performed by the method of Artemia salina and cytotoxicity by MTT method. The phytochemical screening for the detection of allelochemicals was performed. The ethanol extract of propolis of Alagoas showed significant results for antimicrobial activity, and inhibitory activity for Staphylococcus aureus and Candida krusei. The antioxidant activity of the FTC method was 80% to 108.3% hydrogen peroxide kidnapping, the DPPH method showed an EC50 3.97 mg/mL, the content of total phenolic compounds was determined by calibration curve gallic acid, resulting from 0.0005 mg/100 g of gallic acid equivalent. The extract was non-toxic by A. salina method. The propolis extract showed high activity with a higher percentage than 75% inhibition of tumor cells OVCAR-8, SF-295 and HCT116. Chemical constituents were observed as flavonones, xanthones, flavonols, and Chalcones Auronas, Catechins and leucoanthocyanidins. It is concluded that the extract can be tested is considered a potential source of bioactive metabolites.

A espécie Hyptis martiusii Benth é popularmente conhecida como “cidreira do campo”. Possui várias atividades biológicas, dentre elas atividades antifúngica, antiin amatória e inseticida. O objetivo deste trabalho foi investigar a atividade moduladora do óleo essencial das folhas frescas de Hyptis martiusii em associação com diferentes antibióticos frente às bactérias Staphylococcus aureus, Escherichia coli e Pseudomonas aeruginosa, como também a atividade citotóxica da espécie. O estudo utilizou a cim (con- centração inibitória mínima) como forma de avaliação da modulação usando uma inoculação de 100 microlitros de cada estirpe bacteriana. Os ensaios de citotoxicidade foram realizados in vitro utilizando a cultura de linhagem de células do tecido conectivo de camundongo ( broblastos de mamíferos). A pesquisa demonstrou que o Óleo Essencial das folhas de Hyptis martiusii Benth —oehm— apresentou sinergismo apenas em associação com os antibióticos gentamicina e imipenem frente às bactérias Pseudomonas aeruginosa e Escherichia coli. No entanto, apresentou antagonismo em associação com amicacina, gentamicina e imipenem frente às três bactérias estudadas. Em junção com o cipro oxaci- no não apresentou resultados relevantes. Em relação à atividade citotóxica a concentração letal média (LC50) expôs um valor de 263,12 μg/ml. Por m, revelou-se que H. martiusii apresenta atividade citotóxica e baixa atividade sinérgica frente às bactérias avaliadas.

RESUMOA batata-doce (Ipomoea batatas L.) é um vegetal muito cultivado nos países tropicais, usado na alimentação humana e na animal, sendo uma boa fonte de energia, sais minerais e vitaminas. Constitui, ainda, fonte de polifenóis antioxidativos, entre eles, antocianinas e ácidos fenólicos. O objetivo deste estudo foi avaliar a atividade antibacteriana de diferentes extratos de folhas frescas de batata-doce, frente a bactérias de interesse alimentar, e correlacioná-la com os teores de polifenóis totais e de antocianinas. Foram avaliados teores de polifenóis totais e de antocianinas, bem como a atividade antibacteriana de extratos alcoólicos, de infusão e de decocção de folhas de dois acessos de batata-doce, em Porto Alegre, RS, frente a três agentes de interesse em alimentos e alimentação, quais sejam, inóculos padronizados de SalmonellaEnteritidis (ATCC 11076), Staphylococcus aureus(ATCC 25923) e Escherichia coli (ATCC 11229). A avaliação da atividade antibacteriana, expressa em intensidade de atividade de inibição bacteriana (IINIB) e em intensidade de atividade de inativação bacteriana (IINAB), foi baseada em testes de diluição em sistema de tubos múltiplos; as antocianinas foram determinadas por meio de pH diferencial e os polifenóis pelo método de Folin & Ciocalteu. Os extratos alcoólicos inibiram e, ou, inativaram todos os inóculos testados, não obstante o Staphylococcus aureus ter sido significativamente mais resistente. Os extratos obtidos por decocção e infusão, além de apresentarem concentrações muito baixas de antocianinas e menores teores de polifenóis do que os seus correspondentes alcoólicos, não apresentaram atividade antibacteriana. A atividade antibacteriana dos extratos testados foi positivamente correlacionada com os compostos fenólicos e, ou, antocianinas.

Lactic Acid Bacteria (LAB) are indigenous microorganisms occurring in pork sausages. The utilization of selected autochthonous LAB may improve the safety of meat products. This study aims to enumerate and identify LAB in pork sausage and to characterize their safety properties, such as antimicrobial susceptibility and antibacterial activity. A total of 189 sealed packages of pork sausages were collected in seven municipalities (27 samples in each city) of Minas Gerais, Brazil. Microbiological analyses were performed to enumerate LAB. Two pre-selection criteria were applied to 567 isolates of LAB: catalase activity and tolerance to pH 2. A total of 32 strains of UFLA SAU were selected, characterized phenotypically and identified through 16S rDNA region sequencing. The susceptibility to antimicrobial and antibacterial activities of isolates was evaluated. The LAB count ranged from 3.079 to 8.987 log10 CFU/g. Lactobacillus plantarum and Lactobacillus paracasei were identified in the samples. UFLA SAU 11, 20, 34, 86, 131 and 258 showed a profile of susceptibility to four antimicrobials: erythromycin, ampicillin, chloramphenicol and gentamycin. In the antibacterial activity test, with exception of UFLA SAU 1, all other strains showed efficiency in inhibiting Escherichia coli, Salmonella Typhiand Listeria monocytogenes. In the statistical analysis there was interaction among strains of Lactobacillus against the pathogens tested. L. monocytogenes (P=0.05) was more sensitive to Lactobacillus strains and the highest inhibitory activity against this pathogen was achieved by strains UFLA SAU 135, 226, 238 and 258. Thus, UFLA SAU 11, 20, 34, 86, 131, 135, 226, 238 and 258 possess safety characteristics for application in meat products.

American foulbrood (AFB) is a serious worldwide spreading disease in bees caused by Paenibacillus larvae. Plants extracts are known to decrease or inhibit the growth of these bacteria. The purpose of this study was to evaluate the antimicrobial activity of Calendula. officinalis, Cariniana domestica, and Nasturtium officinale extracts against the P. larvae and to evaluate the toxicity of the extracts in bees. In vitro activity against P. larvae of the extracts was evaluated by micro dilution method and the minimal inhibitory concentrations (MICs) were also determined. The concentrations used in the toxicity test were established based on the MIC values and by the spraying application method. The P. larvae was susceptible to the evaluated crude extract of C. officinalis and N. officinale. To C. domestica, only the ethyl acetate (EtAc) fraction and n-butanol (BuOH) fractions had activity against P. larvae. Toxicity analysis in bees showed no toxicity for N. officinale crude extract and for C. domestica BuOH fraction during 15 days of treatment, however, some deaths of bees occurred during the first three days of treatment with C. officinalis and C. domestica EtAc fraction. The results with these species were firstly described and showed that N. officinale crude extract and C. domestica BuOH fraction both presented not toxic effects in the concentration tested by the spraying application method, and can be a useful alternative for treatment or prevention of AFB.

In this work, we used the Minimum Inhibitory Concentration (MIC) technique to evaluate the antibacterial potential of the apitoxin produced by Apis mellifera bees against the causative agents of tooth decay. Apitoxin was assayed in naturaand in the commercially available form. The antibacterial actions of the main components of this apitoxin, phospholipase A2, and melittin were also assessed, alone and in combination. The following bacteria were tested: Streptococcus salivarius, S. sobrinus, S. mutans, S. mitis, S. sanguinis, Lactobacillus casei, and Enterococcus faecalis. The MIC results obtained for the commercially available apitoxin and for the apitoxin in natura were close and lay between 20 and 40µg / mL, which indicated good antibacterial activity. Melittin was the most active component in apitoxin; it displayed very promising MIC values, from 4 to 40µg / mL. Phospholipase A2 presented MIC values higher than 400µg / mL. Association of mellitin with phospholipase A2 yielded MIC values ranging between 6 and 80µg / mL. Considering that tooth decay affects people's health, apitoxin and its component melittin have potential application against oral pathogens.

In vitro and in vivo activity of the Lippia alba essential oil (EO) against Aeromonas sp. was evaluated. In the in vitro assay the minimum inhibitory concentration (MIC) and a minimum bactericidal concentration (MBC) of EO for Aeromonas cells were determined using the microdilution method. Twenty five strains of Aeromonassp. isolated from infected fish obtained from local fish farms were used. MIC and MBC values were 2862 and 5998 µg mL-1 for L. alba EO and 0.5 and 1.2 µg mL-1for gentamicin, respectively. In the in vivo assay silver catfish juveniles (Rhamdia quelen) (7.50 ± 1.85 g and 10.0 ± 1.0 cm) with typical injuries associated to Aeromonas infection were divided into four treatments (in triplicate n=10): untreated fish (negative control), 10 mg L-1 of gentamicin, and 20 or 50 µL L-1 of EO. Fish were maintained in aerated 20 L plastic boxes. After 10 days survival of silver catfish infected with Aermonas sp. and treated with essential oil (50 µL L-1) was greater than 90%.

RESUMO O uso de plantas medicinais no tratamento de doenças é uma estratégia antiga utilizada por praticamente todas as populações do mundo, e, embora novos antibióticos tenham sido desenvolvidos para o controle de micro-organismos infecciosos, às vezes são ineficazes. Diversos extratos de plantas medicinais têm efeitos antimicrobianos, principalmente quando associados à antibióticos de uso clínico, representando alternativa terapêutica para doenças infecciosas. Montrichardia linifera, conhecida popularmente como aninga, é espécie macrófita, aquática emergente de hábito herbáceo, pertencente a família Araceae e ocorre em áreas alagáveis. A utilidade farmacológica desta espécie é diversificada tendo sido relatada como cicatrizante, antirreumático, antidiurético e expectorante. Devido à relevância no campo etnofarmacológico, ampla utilização na medicina popular e escassez de trabalhos relacionados à atividade antibacteriana desta espécie, objetivou-se com este trabalho avaliar a atividade antibacteriana de extratos alcoólicos de folhas de Montrichardia linifera, coletadas na margem do rio Igaraçu, Parnaíba-PI. O extrato foi testado em oito cepas de bactérias: Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae e Pseudomonas aeruginosa. Foram utilizadas as técnicas de verificação da formação de halos de inibição e determinação das concentrações inibitórias e bactericidas mínimas. Os testes antibacterianos evidenciaram como principais resultados que o extrato metanólico seco (EMS), extrato metanólico fresco (EMF), e o extrato etanólico seco (EES), apresentaram ação antibacteriana, enquanto o extrato etanólico fresco (EEF) não apresentou atividade para as bactérias testadas. O EMS foi o mais eficiente, inibindo o crescimento bacteriano na concentração de 200 μg/mL para E. faecalis, 400 μg/mL para S. aureus, 400 μg/mL para S. epidermidis e 2.000 μg/mL para P. aeruginosa. O EMF obteve CIM de 2.000 μg/mL para E. faecalis e EES obteve CIM de 250 μg/mL para E. faecalis. Os resultados demonstraram que M. linifera constitui fonte eficiente de compostos bioativos antibacterianos. Os estudos sobre as propriedades farmacológicas de plantas da família Araceae são escassos, e os resultados deste trabalho são pioneiros em relação a atividade antibacteriana desta espécie.

RESUMO Psidium cattleyanum Sabine, conhecida como “araçá”, é espécie nativa do Bioma Cerrado brasileiro comumente utilizado, segundo levantamento etnobotânico, como planta medicinal para tratar várias doenças tais como: patologias hepáticas, gástricas, lesões teciduais incluindo processos dolorosos. O objetivo deste trabalho foi realizar a triagem fitoquímica com propósito exploratório, investigar a atividade analgésica e antimicrobiana do extrato hidroalcoólico da casca do caule de Psidium cattleyanum Sabine (ECPCS) para apoiar o uso dessa espécie como planta medicinal. Para isso, foram obtidos extratos e frações com solventes orgânicos de polaridade crescente (hexano, diclorometano, acetato de etila e isobutanol) avaliando-se o perfil fitoquímico para determinar as principais classes de metabólitos secundários presentes na espécie. Investigou-se a atividade analgésica pelo teste de contorções abdominais em camundongos induzidas pelo ácido acético (0,6%). A Concentração Inibitória Mínina (CIM) e Concentração Bactericida Mínima (CBM) foram avaliadas através da técnica de microdiluição em caldo contra micro-organismos da microbiota oral. A triagem fitoquímica identificou a presença de taninos, saponinas, flavonoides e terpenos e/ou esteroides. O ECPCS exibiu atividade analgésica periférica nas doses de 200 e 400 mg/kg. O EAC (extrato acetato de casca) o EDC (extrato diclorometânico de casca) desempenharam melhor ação inibitória sobre o crescimento bacteriano de Estafilococos oralis com CIM 100 e 150 respectivamente. O ECPCS desempenhou ação inibitória sobre o crescimento bacteriano. Os resultados dos estudos experimentais comprovaram a presença de compostos secundários tais como, taninos e flavonoides, o que, provavelmente, pode ser associado à atividade analgésica e ao efeito inibitório sobre os micro-organismos testados com o ECPCS, o que justifica o uso medicinal planta.

ABSTRACT The extracts and fractions of leaves and branches of Protium hebetatum D. C. Daly (Burseraceae) were investigated for their antibacterial activity and chemical composition. The methanol extract of branches (EMG) was considered active against the Escherichia coli and the Proteus vulgaris, showing an inhibition zone of 13 mm, and was selected for bioassay-guided phytochemical fractionation. From the technique of broth microdilution, the extract was considered a moderate inhibitor against Staphylococcus aureus, Pseudomonas aeruginosa and Enterococcus faecalis, with a minimum inhibitory concentration (MIC) of 1 mg/mL. The dichloromethane fraction was considered a moderate inhibitor against S. aureus (MIC of 1 mg/mL) and a potent inhibitor against E. faecalis (MIC of 0.5 mg/mL). F1, F2, F5 and F6 from chromatographic column of dichloromethane fraction were considered moderate inhibitors against S. aureus (MIC of 1 mg/mL). Through analysis by a gas chromatography mass spectrometry, eighteen compounds were identified, from which thirteen (isoeugenol, p-vinylguaiacol, metoxyeugenol, coumarin, 5-hydroxy-scopoletin, 4,7-dihydroxy-6-metoxicromam-2-one, 4[(1E]-3-hydroxy-1-propenyl)-2-methoxyphenol, piperonal, scoparon, o-guaiacol, spathulenol, seringol and antiarol) are unprecedented in these species. We also identified the triterpenes α-amyrin and β-amyrin, the steroids stigmasterol and sitosterol and the coumarin scopoletin, which was closely linked to the antibacterial activity of the samples.

ABSTRACT The antibacterial activity of the alkaloid extract from the leaves of Croton bonplandianum Baill. and its main compounds, sparsiflorine and crotsparine, was tested against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa by the resazurin microtitre-plate method. Pure compounds were identified by spectroscopic techniques, mainly 1D and 2D NMR. The alkaloid extract showed activity particularly against the S. aureus and P. aeruginosa. Regarding the pure compounds, the crotsparine was inactive against the microorganisms assayed, whereas the sparsiflorine indicated a moderate activity similar to the alkaloid extract. The Pseudomonas aeruginosa was the most sensitive of the tested microorganisms with MIC of 0.141 mg/mL. The results suggest that the activity of the extract may be credited mainly to the presence of the sparsiflorine. Although the activity of the sparsiflorine does not get close to the antimicrobial drugs in clinical use, it still could be a lead compound for the development of new antibacterial substances.

Microwave-assisted construction of 2-propylquinazolinone1 has been achieved, followed by its subsequent utilities in constructing an attractive series of 2,3-disubstituted functional quinazolinones 2-10. The use of microwave irradiation in performing A/-alkylation for the titled quinazolinone 1 was applied as a simple, efficient and eco-friendly green technique. Furthermore, the in vitro antimicrobial screening of the obtained compounds 3-10 has been investigated against four bacterial strains and two fungal strains. The structure of the synthesized molecules was affirmed using analytical and spectral tools. [ABSTRACT FROM AUTHOR]

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