Orientadores: Marta Cristina Teixeira Duarte, Pedro Luiz Rosalen / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-20T12:06:00Z (GMT). No. of bitstreams: 1 Bersan_SaleteMeiryFernandes_M.pdf: 6812876 bytes, checksum: a263025bff707f77c87f25c8c1f590e9 (MD5) Previous issue date: 2012 / Resumo: A cavidade oral é habitada por uma microbiota mista que, sob determinadas circunstâncias, pode superar as defesas do hospedeiro e agir como oportunista, produzindo diversas manifestações clínicas. Observa-se na literatura um interesse por produtos de origem natural como fonte de novas moléculas bioativas para o controle de afecções orais, entre estes produtos destacam-se os óleos essenciais e seus produtos secundários devido às suas propriedades antimicrobianas. A necessidade de gerar e agregar novas informações acerca da atividade antimicrobiana in vitro de óleos essenciais, impulsionou a realização deste trabalho, envolvendo vinte espécies do Banco de Germoplasmas da "Coleção de Plantas Medicinais e Aromáticas - CPMA" do CPQBA/UNICAMP. Nesse contexto, essa pesquisa teve por objetivo identificar a atividade antimicrobiana in vitro de óleos essenciais e frações de diferentes espécies de plantas medicinais e aromáticas contra os patógenos orais Candida albicans, Fusobacterium nucleatum, Porphyromonas gingivalis, Streptococcus sanguis e Streptococcus mitis, organizados nas formas livre e em biofilme. A atividade antimicrobiana dos óleos e frações foi avaliada através da determinação da Concentração Inibitória Mínima (CIM) e Concentração Bactericida e Fungicida Mínima (CBM/CFM), pelo método da microdiluição. Foram identificadas as classes de substâncias químicas presentes nos óleos essenciais e frações de melhor atividade por CG-EM. Além disso, os óleos essenciais e frações selecionadas foram submetidos à avaliação quanto à possível alteração morfológica causada no biofilme, através de análise por microscopias eletrônica de varredura (MEV). A maioria dos óleos essenciais apresentou atividade antimicrobiana moderada a forte sobre os microrganismos orais, com valores de CIM entre 0,007 a 1,00 mg/mL. Melhores atividades sobre células planctônicas foram exibidas pelas espécies Aloysia gratissima, Coriandrum sativum, Cyperus articulatus, Lippia sidoides e Mikania glomerata, cujos óleos foram fracionados e submetidos a estudos de ação sobre a formação de biofilme pelos microrganismos. Coriandrum sativum se destacou por apresentar os mais baixos valores de CIM em relação às células planctônicas de 0,007 a 0,125. As inibições de aderência variaram de 1.00 % para óleo de Mikania glomerata sobre S. mitis a 63,96 % para o óleo bruto de C. articulatus sobre S. sanguis. Através da análise das imagens obtidas por MEV não foi possível observar alterações na morfologia celular dos microrganismos orais. Porém, houve redução e alterações na organização da estrutura dos biofilmes. A análise da composição química do C. sativum mostrou a presença de compostos majoritários derivados de álcoois e aldeídos, enquanto C. articulatus e A. gratissima apresentaram compostos mono e sesquiterpenos. Em conclusão, o óleo essencial de C. articulatus mostrou o maior percentual de inibição sobre os microrganismos estudados, enquanto o óleo de A. gratissima inibiu a aderência do biofilme de S. mitis / Abstract: The oral cavity is inhabited by a mixed microbial flora which, under determined circumstances, can overcome the host's defenses producing some of clinical pathological manifestations. Considerable interest has been found in the literature concerning natural products as sources new bioactive molecules for oral diseases control and the essential oils and their secondary products stand out with these products due to their antimicrobial properties. In order to produce and aggregate new information relating to in vitro antimicrobial activity of essential oils, this work was designed involving twenty species from the Germplasm Bank of the "Medicinal and Aromatic Plant Collection - CPMA" of CPQBA/UNICAMP, Brazil. Thus the objective of the present research was to identify the in vitro antimicrobial activity of essential oils and fractions of the different species of medicinal and aromatic plants against the oral pathogens Candida albicans, Fusobacterium nucleatum, Porphyromonas gingivalis, Streptococcus sanguis and Streptococcus mitis, organized in the free form and in biofilms. The antimicrobial activity of the oils and fractions was evaluated by determining the Minimum Inhibitory Concentration (MIC) and the Minimum Bactericidal and Fungicidal Concentrations (MBC/MFC) using the micro-dilution method. The classes of bioactive chemical substances present in the essential oils and fractions showing the best activity were identified by GC-MS. In addition the selected essential oils and fractions were submitted to an evaluation to detect any possible morphological alterations caused in the biofilm by way of scanning electronic microscopy (SEM). The majority of the essential oils showed moderate to strong antimicrobial activity against the oral microorganisms, with MIC values between 0.007 and 1.00 mg/mL. Better activities against planktonic cells were shown by the species Aloysia gratissima, Coriandrum sativum, Cyperus articulatus, Lippia sidoides and Mikania glomerata, whose oils were fractionated and submitted to studies of their action against biofilms formation by microorganisms. The essential oil of C. sativum stood out, since it inhibited all investigated species with MIC lowest values, varieting from 0.007 to 0.250 mg/mL, and for MBC from 0.015 to 0.500 mg/mL. The inhibition of biofilm formation varied from 1.00% for Mikania glomerata oil against S. mitis to 63.96% for the crude C. articulatus oil against S. sanguis. No alterations in cell morphology of the oral microorganisms could be observed from an analysis of the SEM images, but there were reductions and alterations in the organization of the biofilm structure. An analysis of the chemical composition of C. sativum showed the presence of alcohol and aldehyde derivatives as major compounds, whereas C. articulatus and A. gratissima showed mono and sesquiterpenes. In conclusion, the essential oil of C. articulatus showed the best results percentage inhibition on the microorganisms under study, whereas the A. gratissima oil inhibited of the S. mitis biofilm formation / Mestrado / Farmacologia, Anestesiologia e Terapeutica / Mestre em Odontologia

Orientador: Carlos Raimundo Ferreira Grosso / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-03T19:13:13Z (GMT). No. of bitstreams: 1 Batista_JulianaAlves_M.pdf: 801759 bytes, checksum: ce425cfeb38d557f43487020978dd9ff (MD5) Previous issue date: 2004 / Resumo: O desenvolvimento e a aplicação de filmes ou coberturas biodegradáveis são técnicas praticadas há vários anos que visam promover melhoria na qualidade do produto embalado ou revestido. O objetivo do presente trabalho foi desenvolver e caracterizar filmes a base de pectina e ácidos graxos e da mistura pectina/gelatina, adicionados ou não de ácidos graxos, e verificar sua eficiência como cobertura para bananas e sementes de brócolos. Os filmes foram caracterizados quanto às propriedades de barreira à água e ao oxigênio, solubilidade em água, propriedades mecânicas, opacidade e microscopia eletrônica de varredura (MEV). A adição crescente dos ácidos láurico, palmítico e esteárico e da mistura (blenda) desses ácidos (1:1:1) em todos os filmes elaborados promoveu um aumento da permeabilidade ao vapor de água, verificando-se através da MEV que não houve incorporação desse material lipídico na matriz filmogênica. Filmes compostos de pectina/gelatina apresentaram aumento da permeabilidade ao vapor de água e da opacidade, diminuição da resistência à tração e aumento da elongação, quando a blenda de ácidos graxos foi adicionada. Os filmes compostos com maior proporção de gelatina apresentaram a menor solubilidade em água. Todos os filmes caracterizados quanto à permeabilidade ao oxigênio apresentaram resultados semelhantes. A partir dos filmes obtidos com menor permeabilidade ao vapor de água e alta resistência à tração, as soluções filmogênicas foram elaboradas e aplicadas como cobertura para banana 'Nanica¿ e para sementes de brócolos 'Ramoso¿. Durante o armazenamento das bananas foram realizadas análises de cor, perda de massa e textura a cada dois dias. A contagem e observação de sementes germinadas foi realizada em média a cada três dias e ao final do experimento as plantas foram submetidas a quantificação do teor de matérias fresca e seca. As bananas com aplicação de cobertura apresentaram menor perda de massa e menor índice de dureza em relação ao controle. A aplicação tornou-se inviável devido a perda acentuada da dureza da fruta. No caso das sementes de brócolos, as coberturas filmogênicas não afetaram a emergência das plantas / Abstract: The development and application of edible films and coatings have been studied for a long time in order to improve the quality of a packed or coated product. The objective of this work was the development and characterization of pectin-based edible films with fatty acids and pectin/gelatin blend films with the addition of fatty acids or not and the application as coatings for bananas and broccoli seeds. Water vapor and oxygen permeability, solubility in water, mechanical properties, opacity and surface morfology were measured for the films. The addition of increasing concentrations of lauric, palmitic and stearic acid and their blend (1:1:1 v/v/v) increased water vapor permeability that was verified by the scanning electron microscopy that showed no incorporation of these lipids into the film matrix. Films with gelatin/pectin blend showed higher water vapor permeability, opacity and elongation and lower tensile strength when the fatty acids blend was additioned. Films with higher concentration of gelatin had lower solubility in water. There was no significant difference in oxygen permeability between all the films. Films with lower water vapor permeability and higher tensile strength were used as coatings for the application on 'Nanica¿ bananas and 'Ramoso¿ broccoli seeds. Weight loss, firmness retention and color were analyzed in each 2 days during the storage of bananas. For the seeds, counting and visual observation of the germinated seeds were effected in each 3 days, and the fresh and dried weight of the plants were determined in the end of the experiment. The coated bananas showed lower weight loss and also firmness retention than the control. The coating application is unfeasible due to the high loss of texture. The coated seeds showed no negative effect of the coating to the growing of the plants / Mestrado / Mestre em Alimentos e Nutrição

Please read the abstract in the section 00front of this document / Dissertation (MSc(Microbiology))--University of Pretoria, 2005. / Microbiology and Plant Pathology / unrestricted

The rhodophytes or red seaweeds are an ancient group of organisms that are related to plants. Like terrestrial plants, they use secondary compounds to protect themselves from microbial infection and grazing by herbivores. However, unlike terrestrial plants, they produce mostly halogenated secondary compounds and rarely alkaloids. Osmundaria serrata (Rhodophyta) is found along the eastern South African coast and the Maldive Islands. Its descriptive common name is “red spirals” and the species is adapted to live in habitats with high wave action. Extracts from this seaweed had previously shown to have antimicrobial activity, but ecologically irrelevant microbes were used to test the extracts. In this study, ten bacteria were isolated from the surface of O. serrata and its habitat, and identified. Mostly aerobic and Gram-negative bacteria were isolated (Halomonas and Pseudomonas species) along with facultatively anaerobic forms (Vibrio spp.) and a Gram-positive (Marinococcus sp.). These were used in bioassays to compare the activity of extracts made from O. serrata and other seaweeds that occur in the same habitat. Marine bacteria are the initial colonizers in biofilm formation and subsequent fouling of surfaces in marine environments. The study of these bacteria in relation to their macroalgal hosts may help to control biofouling of surfaces that cause economic losses worldwide. A comparison was made between using agar dilution and microtitre methods for testing the antibacterial activity of an O. serrata extract. The microtitre method was found to be more sensitive than the agar dilution method. Possibly because e some of the bacteria on the petri plates (in the agar dilution method) were not in direct contact with the toxicant in the growth medium, but were in direct contact in the liquid medium of the wells in the microtitre plates. The extract from 0. serrata was the most active of the thirteen species of macroalgae collected from the same habitat and tested for antibacterial activity. Deformities in bacteria were observed in response to the 0. serrata extract. Increased capsule production and blebbing of the outer membranes were observed by transmission electron microscopy (negative staining). Lanosol diethyl ether was isolated from 0. serrata and tested for antibacterial activity. Lanosol is produced mainly by the rhodophytes, but it is also found in other macroalgae and fungi in lower concentrations. The compound inhibited the test bacteria with average MIC's of 0.27 ± 0.07 mg.mr1 (bacteriostatic) and 0.69 ± 0.15 mg.mr1 (bactericidal). Different forms of biofilm were observed by scanning electron microscopy on the thirteen species of macroalgae. These ranged from a very little biofilm covering on the calcified reds to complex communities on the other macroalgae. The treatment with OS04 vapour before fixation in glutaraldehyde preserved the biofilm structure better than no treatment and indicated that lipids are important in maintaining biofilm structure. Since a complex biofilm community was seen on the surface of 0. serrata, it is unlikely that lanosol functions as an antifouling agent. This chemical seems to multifunctional with antimicrobial and feeding deterrent activities. / Thesis (PhD (Botany))--University of Pretoria, 2006. / Plant Science / unrestricted

The full text of this thesis/dissertation is not available online. Please <a href="mailto:upetd@up.ac.za">contact us</a> if you need access. Read the abstract in the section 00front of this document. / Dissertation (MSc (Microbiology))--University of Pretoria, 2006. / Microbiology and Plant Pathology / unrestricted

Little is known about the distribution of bacterial indicators and pathogens in biofilms on different surface types in natural aquatic environments. This study was conducted to examine the distribution of pathogens and indicator bacteria in biofilms in an agricultural watershed. The study particularly focused on whether biofilms can act as sinks for pathogenic organisms and could be monitored to protect public health. To do so, we monitored the presence of faecal contamination indicators (heterotrophic plate counts, faecal coliforms, enterococci, and E. coli) and particular pathogens (E. coli 0157, Campylobacter sp. and Salmonella sp.) in water, sediment, and in biofilms on river and slate rock, wood, sandpaper, and Lexan™ in Elk Creek (British Columbia, Canada) from December 2005 to April 2007. Faecal indicator concentrations and pathogen presence were evaluated using standard culturing and isolation methods. The results showed that both faecal indicators and pathogens were present at the headwaters and that the use of water column grab samples underestimated faecal indicator numbers. Also, water column grab samples during the dry season were not representative of pathogens present in the creek. This indicates that biofilms might be the main reservoir of Salmonella sp. and pathogenic E. coli O157 in the summer when rainfall (which results in flow changes and sloughing) is limited. Campylobacter sp. was not retrieved in the dry season. Campylobacter on sediment, slate rock and wood showed high correlations with nitrates and enterococci, which could be used as faecal contamination surrogates. Numbers of indicator organisms and pathogens in one-month biofilms were compared to those in long-term biofilms (colonized 12 and 24 weeks) and short-term biofilms (colonized one to three weeks). The comparison showed that surface type, colonization period and water quality all affected the concentration of indicator organisms and pathogens present in biofilms. Finally, results showed high levels of phenotypic antibiotic resistance of E. coli and pathogenic E. coli O157 isolated from the watershed (even at the headwaters), particularly to tetracycline, ampicillin and streptomycin. This study highlights the potential biofilms could play in prediction of water quality changes, the improvement of sampling methods, and the study of aquatic environments. / Science, Faculty of / Resources, Environment and Sustainability (IRES), Institute for / Graduate

The Problem: Biofilms are a community of bacteria that cause infections which are resistant to the immune system and antimicrobial treatments, posing a significant threat for patients with implantable and indwelling medical devices. Purpose: The purpose of this research is to effectively treat biofilms utilizing electric currents assisted by antibiotics. Method: Evaluated the impact of direct electric current with or without vancomycin against Staphylococcus epidermidis biofilms. Results: (1) Electric current reduced the S. epidermidis biofilm and (2) increased the effectiveness of vancomycin. (3) Older biofilms had an increased resistance to vancomycin treatments. (4) Higher electric current intensities and (5) longer duration treatments were more effective against biofilms. Conclusion: Electric current increased the effectiveness of vancomycin against S. epidermidis biofilms.

An increase in the number of bacteria resistant to most of the antibiotics or biocides in common use is a problem faced by industries and the community at large. More bacteria are resistant to moderate levels of biocides, with the bacteria in biofilms being the most difficult to control. High levels of biocides are used and this has detrimental effects on the environment, as biocides are toxic to humans, being carcinogenic, corrosive and producing intolerable odours. Electrochemical activation technology provides an alternative way of controlling microorganisms. ECA water was shown in other countries to have antimicrobial properties. Anolyte, the positively charged solution is benign to fumes and corrosion caused by other biocides. Since anolyte is eco-friendly and present no problems to the environment, it provides a good alternative for controlling microorganisms instead of chemical control. The minimum inhibitory concentration (MIC) of anolyte and its antimicrobial properties against different microorganisms in suspension was evaluated. The I: 1 0 and neat anolyte gave a 100% kill of all organisms tested while 1 :20 dilution gave variable killing percentages ranging from 31 % to 100%. Minimum inhibitory concentration was found to be 20% for most Gram positives and 50% for most Gram negatives. Anolyte did have some antimicrobial properties with MIC differing amongst different organisms. Biofilm control using different concentrations of anolyte and sodium hypochlorite was evaluated. Neat and 1: 10 anolyte removed biofilm while 1: 100 did not have effect on biofilm. The 100 and 300 ppm sodium hypochlorite were effective in removing the biofilm while 10, 25 and 50 ppm could not remove it. Hand wash trials and hospital disinfection using anolyte resulted in a decrease in the number of cfu/25cm3 after treatment. Effective disinfection of hands and hospital equipment was achieved. Different surfaces in a milking parlour were treated with anolyte to test its suitability to disinfect a milking parlour. High numbers of microorganisms and spreaders were observed from the plates before the surfaces were cleaned with anolyte. All spreaders were identified as sporeformers. Results were generally better when anolyte was used as a disinfectant, being able to eliminate spreaders as well. Treatment of chicken carcasses with anolyte to evaluate its effect on their shelf life was also tested. The number of colony forming units on chicken carcasses decreased after treatment of the carcasses with anolyte. Anolyte is therefore a naturally safe disinfectant that could be used in most fields including water distribution systems and industries for biofilm control, hospitals for minimising cross infection, food industries for increasing quality and shelf life of food and also in households for washing hands. / Dissertation (MSc (Microbiology))--University of Pretoria, 2006. / Microbiology and Plant Pathology / unrestricted

Biofilms are important in nature and in engineered processes. Because of this, a fundamental understanding of their growth and behaviour is required. This work aimed at monitoring biofilm growth using a biological rotating reactor and the Rotoscope biofilm monitor. Both methods worked on the principle of a rotating circular disc that was semi-submerged in water and the light reflected of the area that was outside of the water. Light reflectance on the disc was taken three times a day and the average recorded as the daily reading. It was noticed that in both systems, growth of biofilms on the discs caused a decrease in the amount of light reflected. A decrease in light reflectance indicated an increase in biofilm thickness. The growth of biofilm was confirmed by scanning electron microscopy analysis. The addition of a biocide caused a slight increase in light reflectance indicating partial biofilm removal. The Rotoscope was very sensitive to changes in biofilm characteristics. Rotoscope met the requirements needed for an on-line, real-time and non-destructive biofilm monitoring system. The aged anolyte was effective in killing both suspended and biofilm bacteria at a concentration of 1:10 irrespective of its age and storage conditions. Exposure of aerobic bacteria to different concentrations of sodium nitrite at different time intervals indicated that sodium nitrite had a limited, or no biocidal effect on these bacteria mostly encountered in biofilms. The ready to use chlorine dioxide was also used as the means of controlling biofilms. MIC for RTU ClO2 was found to be 80ppm, which in certain instances killed all bacteria immediately upon exposure while in other cases an exposure time of 1h was required. It was indicated that at this concentration, biofilms were removed. This was confirmed by scanning electron microscopy analysis. Proteins of suspended bacteria treated with 1:10 and 1:100 anolyte dilutions and the control were extracted and compared using SDS-PAGE. Protein bands of bacteria treated with 1:10 NaCl derived anolyte were fewer and fainter as compared to those from untreated cells. More bands were produced in cells treated with 1:100 NaCl derived anolyte as compared to the untreated cells. Cells treated with the non-halide anolyte, both 1:10 and 1:100 dilutions, produced more bands than in the untreated cells. Anolyte destroyed vital proteins for bacterial survival causing cell death or it caused fragmentation of proteins to small peptides, reducing the number of viable cells. NaNO2 was ineffective as biocide while aged anolyte and RTU liquid ClO2 were effective as biocides. SDS-PAGE indicated that anolyte killed bacteria by affecting their proteins. / Dissertation (MSc)--University of Pretoria, 2008. / Microbiology and Plant Pathology / unrestricted

Orientador: Theo Guenter Kieckbusch / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-04T01:55:31Z (GMT). No. of bitstreams: 1 Zactiti_EricaMarostica_D.pdf: 5513893 bytes, checksum: 1d3ab4df0091663092f98ac6015a9abe (MD5) Previous issue date: 2004 / Resumo: Questões relacionadas à preservação ambiental têm sido intensamente discutidas, não somente devido à escassez de recursos naturais, mas também, em função da legislação que está cada vez mais rigorosa. Visando o desenvolvimento sustentável, a procura por novos materiais e tecnologias capazes de minimizar os danos ao meio ambiente tem aumentado consideravelmente. Filmes biodegradáveis estão inseridos nesse contexto. Eles são produzidos a partir de polímeros naturais, principalmente polissacarídeos e proteínas, com potencial aplicação nas indústrias farmacêutica e alimentícia. Filmes confeccionados a partir de biopolímeros podem ser utilizados como embalagens antimicrobianas para produtos alimentícios se os agentes ativos são incorporados. Alginato de sódio foi utilizado como substância formadora de filme, cloreto de cálcio como agente reticulante e glicerol como plastificante. Um processo de confecção de filmes reticulados realizado em dois estágios foi desenvolvido, sendo possível obter filmes com baixa solubilidade em água. Filmes com diferentes graus de reticulação foram caracterizados em relação a suas propriedades, tais como: solubilidade em água, permeabilidade ao vapor de água, resistência mecânica, grau de intumescimento e temperatura de transição vítrea. Para o desenvolvimento de embalagens ativas, sorbato de potássio foi incorporado ao filme. Medidas de permeabilidade utilizando uma célula de diafragma indicaram que o processo de migração do sorbato foi afetado pela concentração de sorbato na solução e que o aumento do grau de crosslinking da matriz polimérica diminui a taxa de transferência de massa. Experimentos de liberação de sorbato realizados com água (22 °C) como sorvedouro mostraram rápida liberação do material ativo por difusão (95 % da massa total liberada em aproximadamente 4 minutos). Dados de massa de sorbato liberada apresentaram bom ajuste ao modelo difusional derivado da segunda lei de Fick, com os valores de difusividade variando entre 2,32 x10-7 a 3,32 x10-7cm2/s. Estes valores são inferiores aos dados de difusão de sorbato em filmes de proteína, indicando um uso potencial como sistemas de liberação de substâncias antimicóticas / Abstract: The concern and consciousness relative to the environmental preservation is raising global issues, not only due to the shortage of natural resources, but also because of the legislation that is becoming more and more stringent. Seeking the sustainable development, the number of researches on new materials and technologies that are able to minimize the environmental damages have grown considerably. Biodegradable films are inserted in this context. They are produced from natural polymers, mainly polysaccharides and proteins, with potential applications in the pharmaceutical and food industries. Films manufactured with biopolymers can be used as antimicotic packaging for food products if active agents are incorporated. Sodium alginate was used as film matrix, calcium chloride as reticulating (crosslinking) agent and glycerol as plasticizer. A two-stage reticulation film manufacture process was developed and rendered films with low solubility in water. Films with different degree of reticulation were characterized according to properties such as water solubility, water vapor permeability, mechanical resistance, degree of swelling and glass transition temperature. For the development of active packaging, potassium sorbate was incorporated into the film. Permeability measurements using a diaphragm 0011 indicated that the sorbate migration process was affected by the sorbate concentration and that higher crosslinking degree of the polymeric matrix decreases the mass transfer rates. Sorbate release experiments conducted with water at 22°C as a sink showed rapid exhaustion of the active material by diffusion (95 % of total mass delivered in about 4 minutes). The mass of sorbate release data were well fitted to Fick's second law diffusional model, with O values ranging from 2,32 x10-7 to 3,32 x10-7 cm2/s. These values are lower than published data of sorbate diffusion in protein film, foreseeing a potential use of calcium alginate as an antimicotic packaging / Doutorado / Engenharia de Processos / Doutor em Engenharia Química