Strategies to control Staphylococcus epidermidis biofilms

Staphylococcus epidermidis is the staphylococci species most commonly associated with bacteremia and hospital-acquired infections and has recently arisen as the leading cause of infections related to indwelling medical devices such as vascular catheters, prosthetic joints and artificial heart valves. The prevalence of S. epidermidis in hospital-acquired infections is due to its ability to adhere and form biofilms on biomaterial surfaces. This feature is one of the most important virulence factors found in S. epidermidis. In biofilm form, bacteria are protected from antimicrobial agents and the host immune system contributing to the persistence of biofilm infections. In addition, the emergence of S. epidermidis resistance to conventional therapies, based in the use of traditional antibiotics, leads to the failure of the current treatments used in the combat of S. epidermidis infections and is becoming a major concern. These facts are stimulating the continuous search for novel agents able to eradicate S. epidermidis biofilm infections or that can work in synergy with the currently available antimicrobial agents. New strategies have been showing encouraging in vitro results in controlling S. epidermidis biofilms and seem to be promising alternatives to standard antibiotics usually used in the treatment of S. epidermidis related infections

Response of Staphylococcus epidermidis biofilms cells to the effect of farnesol

Objective:Staphylococcus epidermidis is a leading cause of medical-device-related infections, especially in immunocompromised patients. The treatment of these infections is further complicated by the emergence of multiresistant strains. The ability of S. epidermidis to form biofilms on biotic and abiotic surfaces is believed to contribute significantly to the pathogenesis of these infections. Biofilms are notoriously difficult to eradicate and are often resistant to systemic antibiotic therapy. Recently, farnesol has been described as having antimicrobial properties, and therefore a possible action on the prevention of S. epidermidis related infections. In previous studies it was shown that 300 microM farnesol was effective against S. epidermidis planktonic cells but having only a slight effect on biofilm cells. So, the goal of this study was to assess the antimicrobial activity of higher farnesol concentrations (1 and 100 mM) against biofilm cells of S. epidermidis. Methods: Two S. epidermidis strains biofilm-producing (9142 and 1457) were used in this study. Farnesol (0, 1 mM, 100 mM) was added to 24 h biofilm cells. Biofilm formation was assessed through crystal violet (CV) staining that measure total biomass of biofilm and cellular viability through XTT and colony-forming units (CFU/ml). Results: The results didn't show a significant effect of both farnesol concentrations on biofilm biomass and activity. In fact, biofilm cell reduction was less than 2 Log, similarly to most antibiotics (e.g. tetracycline and vancomycin). Conclusion: Although the reduction promoted by farnesol was less than 3 Log as requested for an antibiotic agent, its efficacy is similar to vancomycin. On account of that we are now testing the combined effect of farnesol with agents that disrupt the biofilm matrix

Farnesol in combination with N-acetylcysteine against staphylococcus epidermidis planktonic and biofilm cells

Staphylococcus epidermidis is the most frequent cause of nosocomial sepsis and catheter-related infections, in which biofilm formation is considered to be the main virulence mechanism. In biofilm environment, microbes exhibit enhanced resistance to antimicrobial agents. This fact boosted the search of possible alternatives to antibiotics. Farnesol and N-acetylcysteine (NAC) are non-antibiotic drugs that have demonstrated antibacterial properties. In this study, the effect of farnesol and NAC isolated or in combination (farnesol+NAC) was evaluated. NAC at 10 × MIC caused a total cell death in planktonic cells. On the other hand, S. epidermidis biofilms exhibited 4 log reduction in viable cell number after a 24h treatment with NAC at the former concentration. Our results demonstrated that there was a higher CFU log reduction of S. epidermidis planktonic cells when farnesol was combined with NAC at 1 × MIC relatively to each agent alone. However, these results were not relevant because NAC alone at 10 × MIC was always the condition which gave the best results, having a very high killing effect on planktonic cells and a significant bactericidal effect on biofilm cells. This study demonstrated that no synergy was observed between farnesol and NAC. However, the pronounced antibacterial effect of NAC against S. epidermidis, on both lifestyles, indicates the use of NAC as a potential therapeutic agent in alternative to antibiotics.Fernanda Gomes and Pilar Teixeira fully acknowledge the financial support of Fundacao para a Ciencia e Tecnologia (FCT) through the grants SFRH/BD/32126/2006 and SFRH/BPD/26803/2006, respectively

CUIDADOS DE ENFERMAGEM DIRECIONADOS AO ACONSELHAMENTO GENÉTICO NO PLANEJAMENTO REPRODUTIVO: UMA REVISÃO BIBLIOGRÁFICA

This study aims to analyze the scientific production on the role of nurses in relation to family planning. This is an integrative literature review with search for articles and informed references in the following databases: MEDLINE, LILACS and SciELO. The search covered the years 2012 to 2022 using the descriptors: Nursing; Genetic counseling; Family planning and nursing care. Several articles were evaluated, of which 10 were included in the study because they met the inclusion criteria. Research indicates that the nurse's role in family planning is fundamental for the functionality and comprehensiveness of actions aimed at the individual and the community. Nurses are key actors in management, education, and care. The research made it possible to understand the importance of nurses in relation to family planning and the problems they face, which demonstrates the need for theoretical-scientific mastery during the nursing consultation to understand the real needs of each user.Este estudio tiene como objetivo analizar la producción científica sobre el papel de las enfermeras en relación con la planificación reproductiva. Esta es una revisión integradora de literatura con búsqueda de artículos y referencias informadas en las siguientes bases de datos: MEDLINE, LILACS y SciELO. La búsqueda abarcó los años 2012 a 2022 utilizando los descriptores: Enfermería; Asesoramiento genético; Planificación reproductiva y cuidados de enfermería. Se evaluaron varios artículos, de los cuales 10 fueron incluidos en el estudio por cumplir con los criterios de inclusión. Investigaciones indican que el papel del enfermero en la planificación reproductiva es fundamental para la funcionalidad y la integralidad de las acciones dirigidas al individuo y a la comunidad. Las enfermeras son actores clave en la gestión, la educación y el cuidado. La investigación permitió comprender la importancia de los enfermeros en relación con la planificación reproductiva y los problemas que enfrentan, lo que demuestra la necesidad del dominio teórico-científico durante la consulta de enfermería para comprender las necesidades reales de cada usuario.Este estudo tem como objetivo analisar a produção científica sobre a atuação do enfermeiro em relação ao planejamento reprodutivo. Trata-se de uma revisão integrativa da literatura com busca de artigos e referências informadas nas seguintes bases de dados: MEDLINE, LILACS e SciELO. A busca abrangeu os anos de 2012 a 2022 utilizando os descritores: Enfermagem; Aconselhamento genético; Planejamento reprodutivo e cuidados de enfermagem. Vários artigos foram avaliados, dos quais 10 foram incluídos no estudo por atenderem aos critérios de inclusão. Pesquisas apontam que a atuação do enfermeiro no planejamento reprodutivo é fundamental para a funcionalidade e integralidade das ações voltadas para o indivíduo e para a comunidade. Os enfermeiros são atores-chave na gestão, educação e cuidados. A pesquisa possibilitou compreender a importância do enfermeiro em relação ao planejamento reprodutivo e os problemas que ele enfrenta, o que demonstra a necessidade do domínio teórico-científico durante a consulta de enfermagem para compreender as reais necessidades de cada usuária.Este estudo tem como objetivo analisar a produção científica sobre a atuação do enfermeiro em relação ao planejamento reprodutivo. Trata-se de uma revisão integrativa da literatura com busca de artigos e referências informadas nas seguintes bases de dados: MEDLINE, LILACS e SciELO. A busca abrangeu os anos de 2012 a 2022 utilizando os descritores: Enfermagem; Aconselhamento genético; Planejamento reprodutivo e cuidados de enfermagem. Vários artigos foram avaliados, dos quais 10 foram incluídos no estudo por atenderem aos critérios de inclusão. Pesquisas apontam que a atuação do enfermeiro no planejamento reprodutivo é fundamental para a funcionalidade e integralidade das ações voltadas para o indivíduo e para a comunidade. Os enfermeiros são atores-chave na gestão, educação e cuidados. A pesquisa possibilitou compreender a importância do enfermeiro em relação ao planejamento reprodutivo e os problemas que ele enfrenta, o que demonstra a necessidade do domínio teórico-científico durante a consulta de enfermagem para compreender as reais necessidades de cada usuária

Effect of N-Acetylcysteine alone and in combination with rifampicin on Staphylococcus epidermidis biofilms

Medical device-associated infections caused by pathogens such as Staphylococcus epidermidis might involve biofilm formation and those are particularly challenging. The involvement of antibiotic resistant Staphylococci, exacerbates the problem. Rifampicin cannot be used as a single agent to treat infections because of the rapid selection of resistant mutants. However, combinations of rifampicin with other anti-staphylococcal agents could prevent the emergence of rifampicin resistance during therapy. N-acetylcisteine (NAC) decreases biofilm formation by a variety of bacteria and reduces the production of extracellular polysaccharide matrix. The goal of this study was to assess the antimicrobial activity of NAC in combination with rifampicin against biofilm of S. epidermidis. Two S. epidermidis strains biofilm-producing (9142 and 1457) were used in this study. 1xMIC (4mg/ml) and 10xMIC (40mg/ml) of NAC and 10mg/l of rifampicin, based on preliminary in vitro data, were added to 24h biofilm cells. Biofilm susceptibility to tested antimicrobial agents was assessed through scanning electron microscopy, crystal violet staining (total biofilm biomass) and cellular viability through XTT and colony forming units (CFU). The effect of NAC 1xMIC was similar to that of the control. Rifampicin, NAC 10xMIC alone and NAC-rifampicin combination (independently of NAC concentration used) showed significant bactericidal effect, promoting a 3-4 log10 decrease in biofilm cells. In conclusion, the results didn’t point to any synergistic effect between the two agents. Nevertheless, NAC seems to be a possible alternative to antibiotics in the treatment of infections associated to S. epidermidis biofilm

Staphylococcus epidermidis biofilms control by N-acetylcysteine and rifampicin

Medical device-associated infections caused by Staphylococcus epidermidis usually involve biofilm formation and its eradication is particularly challenging. Although rifampicin has been proving to be one of the most effective antibiotics against S. epidermidis biofilms, its use as a single agent can lead to the acquisition of resistance. Therefore, we assessed the combined effect of rifampicin with N-acetylcysteine (NAC) known by its mucolytic effect, in the control of S. epidermidis biofilms. Biofilms of 2 S. epidermidis strains (9142 and 1457) were treated with 1x minimum inhibitory concentration (4 mg/mL) and 10x minimum inhibitory concentration (40 mg/mL) of NAC and 10 mg/L (peak serum) of rifampicin alone and in combination. NAC at 40 mg/L alone or in combination with rifampicin (10 mg/L) significantly reduced (4 log10) the number of biofilm cells. Considering their different modes of action, the association of NAC with rifampicin constitutes a promising therapeutic strategy in the treatment of infections associated to S. epidermidis biofilms.Bruna Leite acknowledges the financial support of ISAC/Program Erasmus Munds External Cooperation and the IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, Campus of Gualtar

N-acetylcysteine and vancomycin alone and in combination against staphylococci biofilm

Introduction: The ability of staphylococci to produce biofilm is an important virulence mechanism that allows bacteria both to adhere and to live on artificial surfaces and to resist to the host immune factors and antibiotics. Staphylococcal infections have become increasingly difficult to treat due their antibiotic resistance. Therefore, there is a continuous need for new and effective treatment alternatives against staphylococcal infections. The main goal of this study was to test N-acetylcysteine (NAC) and vancomycin alone and in combination against S. epidermidis and S. aureus biofilms. Methods: Biofilms were treated with NAC at minimum inhibitory concentration (MIC) and 10 × MIC concentrations and vancomycin at MIC and peak serum concentrations. Results: The use of NAC 10 × MIC alone showed a significant antibactericidal effect, promoting a 4-5 log10 CFU/ mL reduction in biofilm cells. The combination of NAC 10 × MIC with vancomycin (independently of the concentration used) reduced significantly the number of biofilm cells for all strains evaluated (5-6 log10). Conclusion: N-acetylcysteine associated to vancomycin can be a potential therapeutic strategy in the treatment of infections associated to biofilms of S. epidermidis or S. aureus.(undefined

Estudo de tecnologias para o tratamento de efluentes na indústria de celulose

O presente trabalho apresenta um mapeamento sistemático das principais tecnologias utilizadas para o tratamento dos efluentes gerados pela indústria de celulose. A metodologia utilizada foi baseada na análise de patentes e de artigos publicados. O estudo realizado visa identificar um panorama das tecnologias já dominadas e daquelas emergentes, como uma forma preliminar para contribuir com uma possível previsão da direção que novos investimentos devem ser feitos, motivado pela tendência mundial de minimizar os impactos ambientais a partir de tratamentos que promovam a sustentabilidade, possibilitando maiores benefícios para a economia e a sociedade. Para ilustrar o estudo com um caso real, foi utilizado a empresa Fibria, maior unidade fabril de produção de celulose do mundo, como exemplo típico de uma Indústria de Celulose. De acordo com as análises dos resultados das buscas por artigos científicos e documentos de patentes, observou-se que com relação aos artigos, há uma preferência pelos tratamentos físicos por separação em membranas e pelos tratamentos químicos por oxidação. No entanto, ainda falta inovação tecnológica nessa área, refletindo na diminuição do número de patentes relacionadas ao tratamento desses efluentes na última década

Efeito modulador do óleo essencial do limão Taiti (Citrus latifolia) em células somáticas de Drosophila melanogaster

Introdução: óleos essenciais são muito utilizados para fins terapêuticos e nas últimas décadas esse interesse tem aumentado exponencialmente devido aos avanços nas terapias naturais. Neste contexto, destaca-se o óleo essencial do limão Taiti, um produto com grande potencial terapêutico e farmacológico. Objetivo: este trabalho objetivou avaliar o efeito carcinogênico e anticarcinogênico do limão Taiti (Citrus latifolia), por meio do teste para detecção de clones de tumores epiteliais em células somáticas de Drosophila melanogaster. Metodologia: larvas de terceiro estágio, do cruzamento entre fêmeas virgens wts/TM3, Sb1 com machos mwh/mwh, foram tratadas cronicamente com diferentes concentrações do óleo essencial do limão Taiti (1,5; 3,0; 6,0 µL) isoladamente e associadas à doxorrubicina (DXR), também foram incluídos dois controles, um negativo (Tween 80 1%) e um positivo (DXR 0,4 mM). Resultados: os resultados revelaram que os indivíduos tratados apenas com as concentrações isoladas do óleo essencial do limão Taiti não apresentaram frequências significativas de tumores quando comparadas ao controle negativo (p>0,05). Contudo, as concentrações associadas apresentaram efeito modulador sobre os danos induzidos pela DXR, pois houve redução significativa (p<0,05) na frequência de tumores, quando comparadas ao controle positivo. Conclusão: o presente trabalho, em condição experimental, atesta que o óleo essencial de limão Taiti (Citrus latifolia) não apresenta ação carcinogênica e sim ação anticarcinogênica em Drosophila melanogaste