Antibiofilm effect of some main components of essentials oils on E. coli biofilm

Fundação para a Ciência e Tecnologia (FCT)European Community - fund FEDER, through Program COMPETE, Project PTDC/SAUESA/6460912006 /FCOMP-01-0124-FEDER-00748

Effect of cashew (Anacardium occidentale L.) peduncle bagasse extract on Streptococcus mutans and its biofilm

This study investigated the antimicrobial activity of cashew (Anacardium occidentale L.) peduncle bagasse extract. Cashewpeduncle bagasse extract was prepared, and its minimal inhibitory concentration (MIC) and minimal bactericidal concentration(MBC), and effect on biofilm formation were determined against the strain Streptococcus mutans UA159. The bagasse extractshowed MIC at a concentration of 500 μg/mL and MBC at 1000 μg/mL against S. mutans. At 250 μg/mL, the extract significantlyreduced the biofilm formation of S. mutans, possibly associated with its effect on planktonic cells. The results of this study showedthat cashew peduncle residue has biomedical potential as an antimicrobial agent against an important pathogen responsible forthe formation of biofilm and subsequent dental caries.(Efeito do extrato do bagasso do pedúnculo do caju (Anacardium occidentale L.) sobre Streptococcus mutans e seubiofilme). Este estudo investigou a atividade antimicrobiana do extrato do bagaço do pedúnculo do caju (Anacardium occidentaleL.). O extrato do bagasse do caju foi preparado e sua concentração inibitória mínima (CIM), concentração bactericida mínima(CBM) e seu efeito sobre a formação de biofilme foram determinadas sobre a estirpe Streptococcus mutans AU 159. O extratodo bagaço apresentou CIM a uma concentração de 500 μg/mL e CBM a 1000 μg/mL contra S. mutans. A 250 μg/mL, o extratoreduziu significantemente a formação de biofilme de S. mutans, possivelmente associado ao seu efeito sobre células planctônicas.Os resultados desse estudo mostraram que o resíduo do pedúnculo do caju tem potencial biomédico como agente antimicrobianocontra um importante patógeno responsável pela formação de biofilme e subsequentemente carie dental

Effect of algae and plant lectins on planktonic growth and biofilm formation in clinically relevant bacteria and yeasts

This study aimed to evaluate the abilities of plant and algae lectins to inhibit planktonic growth and biofilm formation in bacteria and yeasts. Initially, ten lectins were tested on Staphylococcus epidermidis, Staphylococcus aureus, Klebsiella oxytoca, Pseudomonas aeruginosa, Candida albicans, and C. tropicalis at concentrations of 31.25 to 250 μg/mL. The lectins from Cratylia floribunda (CFL), Vatairea macrocarpa (VML), Bauhinia bauhinioides (BBL), Bryothamnion seaforthii (BSL), and Hypnea musciformis (HML) showed activities against at least one microorganism. Biofilm formation in the presence of the lectins was also evaluated; after 24 h of incubation with the lectins, the biofilms were analyzed by quantifying the biomass (by crystal violet staining) and by enumerating the viable cells (colony-forming units). The lectins reduced the biofilm biomass and/or the number of viable cells to differing degrees depending on the microorganism tested, demonstrating the different characteristics of the lectins. These findings indicate that the lectins tested in this study may be natural alternative antimicrobial agents; however, further studies are required to better elucidate the functional use of these proteins.This study was supported by the CAPES (Brazil) under the BEX NT 2052/11NT3 Project, by the IBB-CEB and FCT (Portugal), by the European Community Fund FEDER, and by the COMPETE Program under the auspices of the PTDC/SAU-ESA/646091/2006/FCOMP-01-0124-FEDER-007480 Project. Kyria Santiago Nascimento, Alexandre Holanda Sampaio, Benildo Sousa Cavada, and Edson Holanda Teixeira are Senior Fellows of CNPq. Mr. David Martin helped with the English editing of the paper that was also revised by AJE (American Journal Experts)

Prophylactic outcomes of casbane diterpene in Candida albicans and Candida glabrata biofilms

Biofilms are surface associated communities of microorganisms embedded within a self-produced extracellular matrix and adhered on inert and biotic surfaces. These biological consortia are considered the most prevalent growth form of microorganisms. Biofilm formation is a potent virulence factor for a number of Candida species, as it confers significant tolerance to antimicrobial therapy, primarily by limiting the penetration of substances through the biofilm matrix. Casbane Diterpenes (CD) belongs to the class of diterpenoids isolated from few species of plants from Euphorbiaceae family with important anticancer and antibacterial activities. So, the goal of this study was to assess the antibiofilm effect of a Casbane Diterpene isolated from the stalks of Croton nepetaefolius against Candida albicans and Candida glabrata. Biofilms were developed within the 96- well microtiterplates in the presence of the CD. After 24 hours of growth, 100 μL of cells suspensions (1 x 106 cells ml-1 in Nutrient Broth) and 100 μL of solution of CD (500 - 31.5 μg/mL) were pipetted into each well and incubated for 24 h at 37ºC in an orbital shaker at 120 rpm. Biofilms formation was characterized by total biomass, through crystal violet (CV), and number of viable cells, expressed as log CFU per cm2. CD showed to be able to reduce the biofilm formation of C. albicans and C. glabrata. CD reduced C. albicans biomass in 82, 64, 57 and 27 % at the concentrations of 500, 250, 125 and 62.5 μg/mL, respectively. C. glabrata biomass was reduced in 68 and 26 % at 500 and 250 μg/mL. Regarding the number of viable cells embedded in the yeast biofilms, CD at 500 and 250 μg/mL reduced 2 and 1 log of C. albicans biofilm CFUs, and 2.5 and 1 log for C. glabrata, respectively. Regarding the high resistance and recalcitrance of Candida biofilms to the traditional therapies, CD emerges as a good prophylactic alternative to be used alone or in combination with other traditional drugs

Antibacterial and antioxidant activities of Derriobtusone A isolated from Lonchocarpus obtusus

This study evaluated the effect of derriobtusone A, a flavonoid isolated from Lonchocarpus obtusus, on two important pathogenic bacteria, Staphylococcus aureus and Escherichia coli, as well as its antioxidant activity and toxicity. Planktonic growth assays were performed, and the inhibition of biofilm formation was evaluated. In addition, antioxidant activity was assessed by DPPH radical scavenging assay, ferrous ion chelating assay, ferric-reducing antioxidant power assay, and β-carotene bleaching assay. Toxicity was evaluated by the brine shrimp lethality test. Results showed that derriobtusone A completely inhibited the planktonic growth of S. aureus at 250 and 500 μg/mL; however, it did not have the same activity on E. coli. Derriobtusone A reduced the biomass and colony-forming unit (cfu) of S. aureus biofilm at concentrations of 250 and 500 μg/mL. In various concentrations, it reduced the biofilm biomass of E. coli, and, in all concentrations, it weakly reduced the cfu. Derriobtusone A showed highly efficient antioxidant ability in scavenging DPPH radical and inhibiting β-carotene oxidation. The compound showed no lethality to Artemia sp. nauplii. In conclusion, derriobtusone A may be an effective molecule against S. aureus and its biofilm, as well as a potential antioxidant compound with no toxicity.This study was supported by CAPES (Brazil) through the BEX NT 2052/11NT3 Project and by IBB-CEB and FCT (Portugal) and European Community Fund FEDER, through Program COMPETE, in the ambit of Project PTDC/SAU-ESA/646091/2006/FCOMP-01-0124-FEDER-007480. Otilia Deusdenia Loiola Pessoa, Benildo Sousa Cavada, and Edson Holanda Teixeira are Senior Fellows of CNPq. Mr. David Martin helped with the English editing of the paper

A novel vasorelaxant lectin purified from seeds of Clathrotropis nitida: Partial characterization and immobilization in chitosan beads

A novel lectin from seeds of Clathrotropis nitida (CNA) was purified and characterized. CNA is a glycoprotein containing approximately 3.3% carbohydrates in its structure. CNA promoted intense agglutination of rabbit erythrocytes, which was inhibited by galactosides and porcine stomach mucin (PSM). The lectin maintained its hemagglutinating activity after incubation in a wide range of temperatures (30-60 °C) and pH (6.0-7.0), and its binding activity was dependent on divalent cations (Ca+2 and Mg+2). SDS-PAGE showed an electrophoretic profile consisting of a single band of 28 kDa, as confirmed by electrospray ionization mass spectrometry, which indicated an average molecular mass of 27,406 ± 2 Da and the possible presence of isoforms and glycoforms. In addition, CNA exhibited no toxicity to Artemia sp. nauplii and elicited reversible and dose-dependent vasorelaxation in precontracted aortic rings. CNA was successfully immobilized on chitosan beads and was able to capture PSM in solution. This study demonstrated that CNA is a lectin that has potential as a biotechnological tool in glycomics and glycoproteomics applications. © 2015 Elsevier Inc

Activity of the brasiliensis lectinas of ensiformis Canavalia and Canavalia on the growth âin vitroâ of Rhizobium tropici

RizÃbios sÃo bactÃrias gram-negativas que vivem de maneira simbiÃtica nas raÃzes de leguminosas induzindo a formaÃÃo de nÃdulos. Dentro dos nÃdulos, essas bactÃrias, na sua forma endossimbiÃtica, podem fixar o nitrogÃnio atmosfÃrico e fornecÃ-lo para as cÃlulas da planta hospedeira. Diversas condiÃÃes ambientais sÃo fatores limitantes para a fixaÃÃo biolÃgica de nitrogÃnio e o desenvolvimento do vegetal, como estresse hÃdrico, salinidade, pH e temperatura. Rhizobium tropici CIAT899 à uma estirpe de rizÃbio que forma efetiva simbiose com Phaseolus vulgaris, esta estirpe mostra ser tolerante a diversos estresses ambientais, incluindo altas temperaturas, ambientes Ãcidos e de alta salinidade. Lectinas sÃo (glico) proteÃnas de origem nÃo imune que se ligam especificamente e reversÃvelmente a carboidratos, ou ainda a glicoconjugados. Devido essa capacidade de reconhecer especificamente carboidratos, lectinas mostram ser uma importante ferramenta de estudo que favorece a interaÃÃo entre rizÃbio e planta hospedeira. Nesse trabalho buscamos demonstrar a atividade das lectinas isoladas de sementes de Canavalia brasiliensis (ConBr) e Canavalia ensiformis (ConA) sobre o crescimento âin vitroâ de Rhizobium tropici. Os dados mostraram que a lectina ConBr foi capaz de estimular de maneira significante o crescimento âin vitroâ de Rhizobium tropici. O efeito encontrado foi revertido na presenÃa do aÃÃcar inibidor (manose), sugerindo uma efetiva atividade lectinica. No entanto a lectina ConA nÃo demonstrou nenhuma atividade sobre o crescimento do microrganismo. A lectina ConBr associada com FITC, como jà era esperado, demonstrou interaÃÃo com a superfÃcie bacteriana, esses resultados foram muito semelhantes aos obtidos com ConA, apesar dessa lectina nÃo demonstrar qualquer atividade sobre o crescimento microbiano de Rhizobium tropici. A diferenÃa na atividade biolÃgica destas lectinas, apesar da alta similaridade, provavelmente à devido à diferenÃa estrutural nos seus domÃnios de reconhecimento de carboidrato.Rizobia are gram-negative bacteria that lives as symbiotic cells in roots of leguminous inducing the formation of nodules. Inside of these nodules, these bacteria in their endosymbiotic life style, fixate the atmospheric nitrogen and make it available for the cells from the host plant. Different environment conditions are limiting factors for the biological nitrogen fixation and for the plant development, like drought-stressed, salinity, pH and temperature. Rhizobium tropici CIAT899 is a rizobia‟s strain that has effective symbioses with Phaseolus vulgaris, this strain shows tolerance to many different environment stress, such as high temperatures, acid environment and high salinity. Lectins are (glico) proteins from non-immune origin that binds specific and reversible to carbohydrates or to glicoconjugates. Due to their capacity of recognizing specific carbohydrates, lectins shows to be an important tool that helps the interaction between rizobia and the host plant. In this work we tried to demonstrate the activity of the lectin isolated from Canavalia brasiliensis (ConBr) and Canavalia ensiformis seeds on the in vitro growth of Rhizobium tropici. The data demonstrate that the lectin ConBr was capable of stimulating, in a significant way, the in vitro growth of Rhizobium tropici. The effect that was found was reverted in the presence of the inhibitory sugar (mannose), suggesting an effective lectin activity. However the lectin ConA didn‟t show any activity on the growth of the microorganisms. The ConBr-FITC conjugates, as been expected, showed interaction between the bacteria surface, these results were similar with those from ConA, although this lectin doesn‟t show any activity in the microbial growth of Rhizobium tropici. The difference between the biological activities of these similar lectins, probably is due to their structure differences in the carbohydrate binding domain