Evaluation of leguminous lectins activities against bacterial biofilm formation

Biofilms are composed by microbial cells that are irreversibly associated with a surface and enclosed in a matrix of polymeric material. Lectins are sugar binding proteins of non immune origin that agglutinate cells and ⁄ or precipitate glycoconjugate molecules. Due to their capacity to bind and recognize specific carbohydrates, lectins can be a potent tool in biofilm studies. The search for potential phytochemicals as anti-biofilm agents has become an active area of research, and these proteins can bind to the bacteria or prevent the interaction with the surface and consequently decrease biofilm formation. Thus, the present work aims to evaluate in vitro the antibacterial activity of plant lectinsfrom Canavalia genus against a panel of bacteria of medical relevance, and to inspect their capacity to interfere on the initial adhesion events and biofilm formation. The assays were carried out using different concentrations of leguminous lectins, isolated from Canavalia ensiformis (ConA), C. maritima (ConM) and C. boliviana (ConBol). The effect of lectins was tested on Klebsiella oxytoca ATCC13182, Pseudomonas aeruginosa ATCC10145, Staphylococcus epidermidis CECT231 and Staphylococcus aureus. The bacterial planktonic growth in the presence of the lectins was determined trough absorbance measurement at 640 nm. Adhesion and biofilm assays were performed in polystyrene plates, and chalenged with the three lectins. The biomass accumulated was quantified using crystal violet staining. The results showed that ConA emerged as the most promising lectin since it clearly reduced the bacterial plankctonic growth, specially of the Gram+ strains, with MIC values ranging between 30 and 125 μg/mL. ConA also disturbed the initial adhesion events of all bacteria and disturbed the biofilm formation ability of the Staphylococcus species for all the concentrations tested. Concerning Gram- bacteria, its biofilm formation ability was only prejudiced with higher concentrations of the lectin. Therefore, the results seem to highlight that the antimicrobial activity of ConA was more noticeable in the disturbance of bacterial adhesion and biofilm formation than impairing planktonic growth. In conclusion, our results show that lectins, an important class of natural products, possess promising antibiofilm activity, suggesting that they may have therapeutic potential for the pharmacological treatment of biofilm-associated infections.IBB-CEB, FCT (PTDC/SAU-ESA/64609/2006) and CAPE

Lectinas como Biomarcadores de Tumores de Cavidade Oral: uma Revisão de Literatura

Introdução: Com o advento de novas pesquisas abordando o processo neoplásico, um grupo peculiar de proteínas tem sido amplamente estudado, as lectinas. Estas proteínas possuem a capacidade de se ligarem de forma reversível a carboidratos com alta especificidade. Devido às alterações no padrão glicoproteico de superfície celular durante o processo neoplásico, as lectinas se tornam uma ferramenta potencial como biomarcadores de células neoplásicas. Objetivo: Investigar a produção científica da aplicação lectinas como biomarcadores de lesões neoplásicas e potencialmente neoplásicas da cavidade oral e analisar quais grupos de lectinas e lesões orais foram mais extensamente estudados, com o objetivo final de traçar o perfil dessas publicações. Método: Realizou-se uma pesquisa de artigos científicos integrando periódicos indexados na base de dados Science Direct, Pubmed e BVS. Os critérios de inclusão estabelecidos foram: Tempo – de 1981 a 2010; Descritores – “lectin” AND “binding” AND “oral” AND “tumor”; Resumo/abstract – língua inglesa. Foi obtido um total de 108 artigos. As publicações foram avaliadas e classificadas em categorias pré-estabelecidas, como número/tipos de lesões e número/tipos de lectinas analisadas. As variáveis estudadas foram correlacionadas e o teste Qui-quadrado foi aplicado. Resultados: Houve notadamente um crescimento de estudos utilizando lectinas como biomarcadores tumorais ao longo dos anos, em que a lesão mais amplamente estudada foi o carcinoma espinocelular e a lectina mais avaliada foi a Arachis hypogea (PNA). Conclusão: Pode-se concluir que a utilização de lectinas como ferramenta de diagnóstico é de crescente importância para a pesquisa em cancerologia devido à sua aplicabilidade, versatilidade e fidedignidade de resultados

Uso do cariogram® na avaliação do risco de cárie em crianças em um município brasileiro: estudo piloto

Objetivo: Analisar o risco de cárie dentária em crianças de 12 anos de idade por meio da utilização do Cariogram®. Métodos: Estudo descritivo realizado com 31 crianças de 12 anos de idade de uma escola pública de ensino fundamental em um município do Nordeste brasileiro, no ano de 2009. Coletaram-se dados referentes à experiência de cárie e doenças sistêmicas relacionadas; presença de açúcar na dieta e frequência de ingestão; quantidade de placa e contagem de estreptococos do grupo mutans; uso de produtos fluoretados, fluxo salivar e capacidade tampão. Todos estes dados foram inseridos no Cariogram® para que se pudesse obter um perfil de risco de cárie individual e a capacidade de evitar novas lesões. Resultados: Verificou-se que 78% (n=24) das crianças apresentaram riscos individuais de cárie nos níveis intermediário e alto; 45% (n=14) dos participantes apresentaram menos de 50% de chance de evitar novas lesões de cáries. Ainda, que 6,45% (n= 2) das crianças apresentavam possibilidade de evitar novas lesões de cárie menor que 75%, ou seja, configuravam em alto risco de desenvolvimento de cárie; e 12,90% (n= 4) apresentavam uma possibilidade maior que 75%, sendo caracterizado como baixo risco de evitar estas lesões. Houve associações positivas (p<0,05) entre presença de açúcar na dieta e fluxo salivar, em que indivíduos com dieta cariogênica apresentavam fluxo salivar diminuído. Conclusão: Verificou-se um padrão de risco de cárie nos níveis intermediário e alto, com susceptibilidade acima de 10% e possibilidade de evitar novas lesões de cárie inferior a 50%

Uso do cariogram® na avaliação do risco de cárie em crianças em um município brasileiro: estudo piloto

Objective: To analyze the risk of dental caries in 12-year-old children through the use of Cariogram®. Methods: Descriptive study conducted with 31 children, aged 12 years, in apublic elementary school in a city of the Brazilian Northeast, in 2009. Data was collected regarding caries experience and related systemic disease; presence of sugar in the diet and intake frequency; Streptococcus mutans biofilm growth and bacterial counts; use of fluoride products, salivary flow and buffering capacity. All this data was inserted into Cariogram®, in order to obtain a profile of individual caries risk and the ability to prevent new cariouslesions. Results: It was found that 78% (n=24) of the children had individual risk of dental caries in the intermediate and high levels; 45% (n=14) of the participants had less than a 50% chance of avoiding new cavities. Furthermore, 6.45% (n=2) of the children had less than 75% possibility of avoiding new carious lesions, i.e., they featured high risk of caries development, and 12.90% (n=4) had a possibility of more than 75%, being characterized as low risk of developing such injuries. There were positive associations (pObjetivo: Analizar el riesgo de caries dentaria en niños de 12 años de edad con la utilización del Cariogram®. Métodos: Estudio descriptivo realizado con 31 niños de 12 años de edad en uma escuela pública de enseñanza fundamental de un municipio Del Nordeste brasileño en 2009. Se recogió datos sobre la experiência de caries y enfermedades sistémicas relacionadas; presencia de azúcar en la dieta y frecuencia de ingestión; cantidad de placa y recuento de estreptococus del grupo mutans; el uso de productos fluorados, flujo salival y capacidad de tapón. Todos los datos fueron inseridos en el Cariogram® para obtener un perfil de riesgo de caries individual y la capacidad de evitar nuevas lesiones. Resultados: Se verificó que el 78% (n=24) de los niños presentaron riesgos individuales de caries en los niveles intermediario y alto; el 45% (n=14) de los participantes presentaron menos del 50% de oportunidad de evitar nuevas lesiones de caries. Además, el 6,45% (n= 2) de los niños presentaron la posibilidad de evitar nuevas lesiones de caries abajo del 75%, es decir, presentaron riesgo elevado de desarrollo de caries; y el 12,90% (n= 4) presentaron una mayor posibilidad que el 75% caracterizando el bajo riesgo en evitar estas lesiones. Hubieron asociaciones positivas (pObjetivo: Analisar o risco de cárie dentária em crianças de 12 anos de idade por meio da utilização do Cariogram®. Métodos: Estudo descritivo realizado com 31 crianças de 12 anos de idade de uma escola pública de ensino fundamental em um município do Nordeste brasileiro, no ano de 2009. Coletaram-se dados referentes à experiência de cárie e doenças sistêmicas relacionadas; presença de açúcar na dieta e frequência de ingestão; quantidade de placa e contagem de estreptococos do grupo mutans; uso de produtos fluoretados, fluxo salivar e capacidade tampão. Todos estes dados foram inseridos no Cariogram® para que se pudesse obter um perfil de risco de cárie individual e a capacidade de evitar novas lesões. Resultados: Verificou-se que 78% (n=24) das crianças apresentaram riscos individuais de cárie nos níveis intermediário e alto; 45% (n=14) dos participantes apresentaram menos de 50% de chance de evitar novas lesões de cáries. Ainda, que 6,45% (n= 2) das crianças apresentavam possibilidade de evitar novas lesões de cárie menor que 75%, ou seja, configuravam em alto risco de desenvolvimento de cárie; e 12,90% (n= 4) apresentavam uma possibilidade maior que 75%, sendo caracterizado como baixo risco de evitar estas lesões. Houve associações positivas (

Effect of Lectins from Diocleinae Subtribe against Oral Streptococci

Surface colonization is an essential step in biofilm development. The ability of oral pathogens to adhere to tooth surfaces is directly linked with the presence of specific molecules at the bacterial surface that can interact with enamel acquired pellicle ligands. In light of this, the aim of this study was to verify inhibitory and antibiofilm action of lectins from the Diocleinaesubtribe against Streptococcus mutans and Streptococcus oralis. The inhibitory action against planctonic cells was assessed using lectins from Canavaliaensi formis (ConA), Canavalia brasiliensis (ConBr), Canavalia maritima (ConM), Canavalia gladiata (CGL) and Canavalia boliviana (ConBol). ConBol, ConBr and ConM showed inhibitory activity on S. mutans growth. All lectins, except ConA, stimulated significantly the growth of S. oralis. To evaluate the effect on biofilm formation, clarified saliva was added to 96-well, flat-bottomed polystyrene plates, followed by the addition of solutions containing 100 or 200 µg/mL of the selected lectins. ConBol, ConM and ConA inhibited the S. mutans biofilms. No effects were found on S. oralis biofilms. Structure/function analysis were carried out using bioinformatics tools. The aperture and deepness of the CRD (Carbohydrate Recognition Domain) permit us to distinguish the two groups of Canavalia lectins in accordance to their actions against S. mutans and S. oralis. The results found provide a basis for encouraging the use of plant lectins as biotechnological tools in ecological control and prevention of caries disease

In Vitro Antibacterial and Antibiofilm Activity of Lippia alba Essential Oil, Citral, and Carvone against Staphylococcus aureus

In vitro antimicrobial and antibiofilm activities of the Lippia alba essential oil and its major components (citral and carvone) against Staphylococcus aureus were investigated. Essential oils (LA1EO, LA2EO, and LA3EO) were extracted from the aerial parts of three L. alba specimens by hydrodistillation and analyzed by gas chromatography coupled to a mass spectrometer. Minimum Inhibitory Concentrations (MIC) and Minimum Bacterial Concentration (MBC) were determined by the microdilution method. For the antibiofilm assays, the biomass formation in the biofilm was evaluated by the microtiter-plate technique with the crystal violet (CV) assay and the viability of the bacterial cells was analyzed. All oils and their major components presented antibacterial activity, and the lowest MIC and MBC values were 0.5 mg mL−1 when LA1EO and citral were used. Potential inhibition (100%) of S. aureus biofilm formation at the concentration of 0.5 mg mL−1 of all EOs was observed. However, the elimination of biofilm cells was confirmed at concentrations of 1 mg mL−1, 2 mg mL−1, 2 mg mL−1, and 0.5 mg mL−1 for LA1EO, LA2EO, LA3EO, and citral, respectively. The results obtained in the present research point to the promising antibacterial and antibiofilm potential of L. alba EOs against S. aureus, a species of recognized clinical interest

Plectranthus amboinicus essential oil and carvacrol bioactive against planktonic and biofilm of oxacillin- and vancomycin-resistant Staphylococcus aureus

Abstract Background The emergence of multidrug-resistant bacteria is a worldwide concern and in order to find an alternative to this problem, the occurrence of antimicrobial compounds in Plectranthus amboinicus essential oil was investigated. Thus, this study aims to determine susceptibility of Staphylococcus aureus isolated from food to antibiotics, P. amboinicus essential oil (PAEO) and carvacrol. Methods Leaves and stem of P. amboinicus were used for extraction of essential oil (PAEO) by hydrodistillation technique and EO chemical analysis was performed by gas chromatography coupled to a mass spectrometer. S. aureus strains (n = 35) isolated from food and S. aureus ATCC 6538 were used to evaluate the antimicrobial and antibiofilm activity of PAEO and carvacrol. All strains (n = 35) were submitted to antimicrobial susceptibility profile by disk diffusion method. Determination of MIC and MBC was performed by microdilution technique and antibiofilm activity was determined by microtiter-plate technique with crystal violet assay and counting viable cells in Colony Forming Units (CFU). Results Carvacrol (88.17%) was the major component in the PAEO. Antibiotic resistance was detected in 28 S. aureus strains (80%) and 12 strains (34.3%) were oxacillin and vancomycin-resistant (OVRSA). From the 28 resistant strains, 7 (25%) showed resistance plasmid of 12,000 bp. All strains (n = 35) were sensitive to PAEO and carvacrol, with inhibition zones ranging from 16 to 38 mm and 23 to 42 mm, respectively. The lowest MIC (0.25 mg mL−1) and MBC (0.5 mg mL−1) values were observed when carvacrol was used against OVRSA. When a 0.5 mg mL−1 concentration of PAEO and carvacrol was used, no viable cells were found on S. aureus biofilm. Conclusion The antibacterial effect of carvacrol and PAEO proves to be a possible alternative against planktonic forms and staphylococcal biofilm