Colistin surface conditioning impairs Pseudomonas aeruginosa biofilm formationand enhances ciprofloxacin antimicrobial activity

Bacterial biofilms on medical devices (MD) are commonly associated with persistent infections. Biofilm formation is central to pathogenesis due to the ability of the biofilm-entrapped bacteria to evade the host immune responses and the increased antimicrobial resistance phenotype often shown by sessile microorganisms. In order to control the infections related with MD, antimicrobial peptide conditioning of MD surfaces can be an attractive answer. Colistin (COL), an important cationic antimicrobial peptide (AMP) produced by Bacillus polymyxa strains, was used to coat polystyrene (PS) surfaces. This work aims at characterizing the antimicrobial effect of COL surface coating to impair Pseudomonas aeruginosa adhesion and subsequent biofilm formation. The response of P. aeruginosa 24 h biofilms treatment with Ciprofloxacin (CIP) in non-conditoned and COL conditioned surfaces was also assessed P. aeruginosa from collection (ATCC 10145) (PAC) and P. aeruginosa isolated (PAI) from a medical device (endoscope) were used as biofilm producers. PS surfaces were pre-conditioned with 64 mg/L of COL during 30 min. Biofilms were then developed in unconditioned and COL-conditioned surfaces, being after treated with Ciprofloxacin (CIP) at 0.75 mg/L. Biofilms were phenotypically characterized in terms of biomass, respiratory activity and cell number. Results showed that, in general, the MD isolate produces biofilms with more mass and activity but less number of cells than the reference strain, being the action of COL conditioning or CIP treatment similar for both strains. The surface conditioning with COL was very efficient, as it impaired significantly biofilm formation in terms of mass and activity, allowing the adhesion of just 3-log of cells. The CIP treatment of biofilms developed in unconditioned and COL-conditioned surfaces, promoted reduction of biofilm mass, activity and 2-log of number of biofilm cells. Concerning the combined application of COL surface conditioning and biofilm treatment with CIP it was observed an increase in CIP efficacy in biofilm sanitation, especially regarding biofilm-entrapped cell reduction. In fact, the combination of conditioning/treatment promoted an accentuated reduction of the biofilm mass and activity and caused a reduction of 4-log of biofilm-entrapped cells. This study demonstrates the potential use of COL surface conditioning since this surface treatment impairs biofilm formation, probably interfering in the transition from irreversible attached cells to mature biofilms.Moreover, and as consequence of the reduced amount of biofilms attached to COL-conditioned surfaces, adhered cells or thin biofilms become more exposed to the subsequent action of CIP. This study highlights a promising use of COL as MD coating and a synergistic effect between COL surface conditioning and CIP antimicrobial activity. The financial support from IBB-CEB and Fundação para a Ciência e Tecnologia (FCT) and European Community fund FEDER, trough Program COMPETE, in the ambit of the Project PTDC/SAU-SAP/113196/2009 /FCOMP-01-0124-FEDER-016012 and Idalina Machado PhD Grant (SFRH/BD/31065/2006) are gratefully acknowledged

Susceptibility patterns and cross-resistance evaluation of several biofilm-producing P. aeruginosachallenged by antibiotics

P.aeruginosa (PA) is an opportunistic pathogen responsible for high percentage of nosocomial infections. Its virulence and persistence rises when bacteria switch from planktonic to biofilm state and when facing antimicrobial pressures. This study aimed to evaluate the antimicrobial tolerance and regrowth of several biofilmproducing PA after antibiotic treatment, and the occurrence of cross-resistance to other antimicrobials. PAO, ATCC, CGCT and an isolated strain were used to form 1-day old biofilms in the presence of ciprofloxacin (CIP). Biofilm regrowth was evaluated after 48h, 72h and 96h after addition of, respectively, fresh medium, medium with antibiotic and antibiotic-free medium again. The final 4-days old biofilms were then attacked with CIP, gentamicin, rifampicin and benzalkonium chloride. After 24h and 72h of biofilm growth, it was observed a good reduction of the biofilm mass, respiratory activity and CFU/cm2. However, PA biofilm regrowth with similar or even higher cell numbers, comparatively to control, were noticed always the antibiotic-free medium was added. Data allowed speculating that the adhered bacteria that survived to antibiotic therapy may become more resistant to CIP or to other antimicrobials. Luckily, data did not show evidence of cross-resistance to the antimicrobials tested. Biofilms formed in the presence of CIP appeared to be more susceptible to the anti-biofilm action of antimicrobials. Although it has been observed marked biofilm regrowth after good levels of biofilm eradication due to antibiotic treatment, the resulting biofilms challenged by CIP seemed to be less tolerant to the action of other antimicrobials.IBB-CEB and FCT (PTDC/SAU-ESA/64609/2006; SFRH/BD/31065/2006; SFRH/ BD/47613/2008

Studies of decolorization of azo dyes by ascomycete yeasts

Poster apresentado no Micro'2001, Póvoa de Varzim, 2001.Azo dyes are the most widely used colored materials in textile industries and its biodegradability is, therefore, an important issue in the biological treatment of dye-containing wastewater. However, these treatments are not totally effective in removing color of textile dye wastewater since dyes are typically resistant to oxidative degradation. Most biodegradation studies on azo dyes involve bacterial species, and anaerobic or microaerophylic conditions are usually refered to as being favorable to a reduction step producing colorless amines. Our group has succeeded in isolating a number of yeast species, which revealed an interesting potential in the color removal of azo dyes in aerated culture media. Three of these species (UM2, UM41 and UM45), where used in the present work. The tested dyes included several sulphonic and carboxylic monoazo dyes, and several reactive textile dyes. The results which will be described refer to (i) the conditions and time-course of the decolorization process, (ii) the optimization of the decolorization medium, aiming at the reduction in yeast extract concentration, (iii) the identification of dye reduction products formed in the course of the decolorization process and (iv) the effect of those reduction products on yeast specific growth rates.BIOEFTEX Project

An integrated framework for supporting fuzzy decision-making in networked manufacturing environments

In this paper we propose an integrated framework, based on smart objects to support fuzzy decision-making processes applied to manufacturing environments. The processes involved range from factory-production level up to higher decision-making levels, either in the context of traditional single enterprises, up to the one of supply chains and distributed and ubiquitous manufacturing environments. Therefore, the proposed framework promotes contributions for solving different kind of problems, including, among others: networked supply chain management; production planning and control; factory supervision and productivity management; real-time monitoring; data acquisition and processing. The web access via different middleware devices and tools at different process levels, along with the use of integrated algorithms and smart objects, which is possible and will promote an optimized use of knowledge and resources for supporting better decision-making. Moreover, the proposed framework also aims at promoting a wider collaboration process among various groups of stakeholders.This work was supported by FCT “Fundação para a Ciência e a Tecnologia” under the program: PEst20152020.info:eu-repo/semantics/publishedVersio

A simulation platform prototype for evaluating alternative scenarios of members integration in virtual organizations

Companies are facing growing challenges motivated by globalization. A globalized market means that the number of companies with which they will need to compete to maintain or enlarge their market share is increased. Additionally, it also brings greater opportunities to conquer new markets and increase existing market shares, since the geographical, political and economical boundaries are gradually being removed. This paper proposes and illustrates the use of a platform prototype for enabling the evaluation and selection of attractive members for being included as members in a virtual organization. An extended simulation study is described and results obtained presented which show advantage of a used dynamic evaluation and selection model, based on a varying set of criteria.This work has been supported by COMPETE: POCI-01-0145-FEDER-007043 and FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2013.info:eu-repo/semantics/publishedVersio

Integrated platform for real-time control and production and productivity monitoring and analysis

In this paper is proposed the IndustSystems, which is an integrated platform that aims at controlling and monitoring of production and evaluation of productivity in real time, via web access, using hybrid and scheduling algorithms that allow management and optimized use of production resources and perfect synchronization of production flows.This work was supported by FCT “Fundação para a Ciência e a Tecnologia” under the program: PEst20152020.info:eu-repo/semantics/publishedVersio

Multipolar mitosis and aneuploidy after chrysotile treatment: a consequence of abscission failure and cytokinesis regression

Chrysotile, like other types of asbestos, has been associated with mesothelioma, lung cancer and asbestosis. However, the cellular abnormalities induced by these fibers involved in cancer development have not been elucidated yet. Previous works show that chrysotile fibers induce features of cancer cells, such as aneuploidy, multinucleation and multipolar mitosis. In the present study, normal and cancer derived human cell lines were treated with chrysotile and the cellular and molecular mechanisms related to generation of aneuploid cells was elucidated. The first alteration observed was cytokinesis regression, the main cause of multinucleated cells formation and centrosome amplification. The multinucleated cells formed after cytokinesis regression were able to progress through cell cycle and generated aneuploid cells after abnormal mitosis. To understand the process of cytokinesis regression, localization of cytokinetic proteins was investigated. It was observed mislocalization of Anillin, Aurora B, Septin 9 and Alix in the intercellular bridge, and no determination of secondary constriction and abscission sites. Fiber treatment also led to overexpression of genes related to cancer, cytokinesis and cell cycle. The results show that chrysotile fibers induce cellular and molecular alterations in normal and tumor cells that have been related to cancer initiation and progression, and that tetraploidization and aneuploid cell formation are striking events after fiber internalization, which could generate a favorable context to cancer development

Dibucaine in Ionic-Gradient Liposomes: Biophysical, Toxicological, and Activity Characterization

Administration of local anesthetics is one of the most effective pain control techniques for postoperative analgesia. However, anesthetic agents easily diffuse into the injection site, limiting the time of anesthesia. One approach to prolong analgesia is to entrap local anesthetic agents in nanostructured carriers (e.g., liposomes). Here, we report that using an ammonium sulphate gradient was the best strategy to improve the encapsulation (62.6%) of dibucaine (DBC) into liposomes. Light scattering and nanotracking analyses were used to characterize vesicle properties, such as, size, polydispersity, zeta potentials, and number. In vitro kinetic experiments revealed the sustained release of DBC (50% in 7 h) from the liposomes. In addition, in vitro (3T3 cells in culture) and in vivo (zebrafish) toxicity assays revealed that ionic-gradient liposomes were able to reduce DBC cyto/cardiotoxicity and morphological changes in zebrafish larvae. Moreover, the anesthesia time attained after infiltrative administration in mice was longer with encapsulated DBC (27 h) than that with free DBC (11 h), at 320 μM (0.012%), confirming it as a promising long-acting liposome formulation for parenteral drug administration of dibucaine.Fil: Couto, Verônica M.. Universidade Estadual de Campinas; BrasilFil: Prieto, Maria Jimena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB | Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB | Universidad Nacional de la Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB; ArgentinaFil: Igartúa, Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB | Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB | Universidad Nacional de la Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB; ArgentinaFil: Feas, Daniela Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB | Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB | Universidad Nacional de la Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB; ArgentinaFil: Ribeiro, Lígia N.M.. Universidade Estadual de Campinas; BrasilFil: Silva, Camila M.G.. Universidade Estadual de Campinas; BrasilFil: Castro, Simone R.. Universidade Estadual de Campinas; BrasilFil: Guilherme, Viviane A.. Universidade Estadual de Campinas; BrasilFil: Dantzger, Darlene D.. Universidade Estadual de Campinas; BrasilFil: Machado, Daisy. Universidade Estadual de Campinas; BrasilFil: Alonso, Silvia del Valle. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB | Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB | Universidad Nacional de la Plata. Instituto Multidisciplinario de Biología Celular. Grupo Vinculado al IMBICE - Grupo de Biología Estructural y Biotecnología-Universidad Nacional de Quilmes - GBEyB; ArgentinaFil: de Paula, Eneida. Universidade Estadual de Campinas; Brasi

PESQUISA PARTICIPATIVA DE BASE COMUNITÁRIA (PPBC): UMA METODOLOGIA PARA ESTUDOS DE PARTICIPAÇÃO DE ADOLESCENTES

O estudo objetiva apresentar a Pesquisa Participativa de Base Comunitária (PPBC) como metodologia utilizada em estudo de participação com adolescentes. A metodologia adotada aborda questões relacionadas ao estudo e a intervenção em determinado grupo de pessoas, a comunidade a ser estudada, que nesse estudo são os adolescentes. Para tanto, alguns princípios devem ser seguidos para que as vantagens do método sejam evidentes. A pesquisa, nesse estudo relatada, enfatizou a temática participação na promoção da saúde do adolescente em uma perspectiva mais abrangente, sendo desenvolvida com um grupo de adolescentes que vivenciaram momentos educativos/participativos, baseados nos princípios da PPBC. A pesquisa abrangeu seis encontros, cada um foi planejado juntamente com os adolescentes. A avaliação do processo realizou-se mediante a observação e percepções colhidas através de registros escritos e verbais, além das manifestações não verbais. Destacaram-se como pontos positivos na implementação da metodologia a consecução de autonomia e vínculo entre a comunidade estudada e a científica (adolescentes e pesquisadores), e o aprendizado de temas realizados a promoção da saúde do público adolescente. Evidenciou-se que esse tipo de metodologia adequou-se ao estudo com adolescentes, tendo em vista que os passos foram seguidos para o alcance do objeto do estudo