Traballo fin de grao (UDC.CIE). Bioloxía. Curso 2016/2017 | [Resumen] Los ríos son la fuente de agua dulce más importante para los seres humanos, por lo que es necesario conocer su estado y evitar la contaminación asociada al rápido desarrollo de la población, que conlleva un continuo desgaste del medio natural. Por este motivo, se ha llevado a cabo un estudio sobre la calidad del agua del río Mero a partir de distintos puntos de su curso para conocer cómo las actividades humanas afectan a sus aguas. Para ello se ha realizado un análisis microbiológico de coliformes totales, coliformes fecales, enterococos y Pseudomonas, encontrando un aumento progresivo de coliformes fecales desde el nacimiento del río hasta su desembocadura. También se ha realizado un estudio sobre el desarrollo de la microalga Chlamydomonas moewusii, utilizando el agua muestreada para preparar el medio de cultivo necesario. Tras el análisis, se concluye que, aunque la calidad del agua es buena tanto para el desarrollo de las plantas como de los animales acuáticos asociados al río, el aumento de coliformes fecales en las zonas urbanas así como el aumento del crecimiento de C. moewusii en estos últimos puntos, evidencian una alta descarga de aguas residuales domésticas portadoras de materia orgánica y contaminación fecal, por lo que se hace necesario controlar los vertidos a las aguas naturales para evitar los problemas de salud que podrían provocar las bacterias asociadas a la presencia de contaminación fecal en las aguas. | [Resumo] Os ríos son a fonte de auga doce máis importante para os seres humanos, polo que é necesario coñecer o seu estado e evitar a contaminación asociada ó rápido desenvolvemento da poboación, que supón un continuo desgaste do medio natural. Por este motivo levouse a cabo un estudo sobre a calidade da auga do río Mero a partir de distintos puntos do seu curso para coñecer cómo as actividades humanas afectan as súas augas. Para isto realizouse unha análise microbiolóxica de coliformes totales, coliformes fecais, enterococos e Pseudomonas, encontrando un aumento progresivo de coliformes fecais dende o nacemento do río ata a súa desembocadura. Realizouse tamén un estudo sobre o desenvolvemento da microalga Chlamydomonas moewusii, empregando a auga recollida para preparar o medio de cultivo necesario. Tras a análise, conclúese que, aínda que a calidade da auga é boa tanto para o desenvolvemento das plantas como dos animais acuáticos asociados ó río, o aumento de coliformes fecais nas zonas urbanas así como o aumento do crecemento de C. moewusii nestes últimos puntos, evidencian una alta descarga de augas residuais domésticas portadoras de materia orgánica e contaminación fecal, polo que se fai necesario controlar os vertidos ás augas naturais para evitar os problemas de saúde que poderían provocar as bacterias asociadas á presenza de contaminación fecal nas augas. | [Abstract] Rivers are the most important source of fresh water for humans, so it´s necessary to know their condition and avoid contamination associated with the fast increasment of the population, which entails a continuous wastage of the natural environment. For this reason, a study has been conducted on the water quality of the river Mero from different points of its course to know how human activities affect its waters. Because of this, a microbiological analysis of total coliforms, faecal coliforms, enterococci and Pseudomonas has been carried out, finding a progressive increase of faecal coliforms from the source of the river to its mouth. Another study has been made on the microalgae Chlamydomonas moewusii growth, using the sampled water to prepare the necessary culture medium. After the analysis, it is concluded that, although the water quality is good for the development of the plants and the aquatic animals associated to the river, the increase of faecal coliforms in urban areas as well as the growth of C. moewusii in the last points, evidences a high discharge of domestic wastewaters bearing organic matter and faecal contamination, reason why it is necessary to control the discharges to the natural waters to avoid the health problems that the bacteria associated to the presence of faecal contamination in the waters could provoke.

Water quality monitoring is used to determine the impact of human activities on the environment. We evaluated water quality in the Água Boa stream, located within the municipality of Dourados, State of Mato Grosso do Sul, Brazil, by analyzing physico-chemical, chemical, and microbiological parameters, as well as chlorophyll concentrations. Five sets of water samples were collected between December 2012 and November 2013 from three locations within the stream. The results showed the presence of Escherichia coli and antibiotic-resistant Pseudomonas spp. strains and high concentrations of organic matter (total dissolved solids), inorganic species (Mg, Ca, and Fe), and agrochemical residues (thiamethoxam). The main stream water contaminants are derived from urban, industrial, and agricultural activities within the watershed. Given the presence of contaminants, it is important that such findings are disseminated in order to highlight the risks that contact with this water may pose to human health. To preserve the environment and improve site conditions, people would need to participate by demanding that normative national and international standards be respected and that the situation be supervised by the competent governmental agencies; this would make it possible to reverse or minimize contamination problems within the Água Boa stream.

Mestrado em Engenharia Alimentar - Instituto Superior de Agronomia | Vegetables in their natural state are susceptible to spoilage by microorganisms at a rate that depends on some intrinsic and extrinsic factors. Consumers are increasingly demanding for convenient ready-to-eat vegetables and with fresh like quality, not only because their nutritional reasons but also due to the increasing participation of women in the labor market. Food contamination is a enormous public health problem, but it could be controlled by the use of natural preservatives, such as essential oils, instead of synthetic ones. Essential oils are the odorous, volatile products resulting from the secondary metabolism of herbs, usually produced in special cells or group of cells. The essential oil composition can vary due several factors such as climate, soil composition, plant organ, age, vegetative cycle stage and extraction method. The antimicrobial effect of essential oils is attributed to a small number of terpenoid and fenolic compounds like thymol, carvacrol and eugenol. This compounds act directly on the cytoplasmic membrane, causing changes in its structure and functions. Essential oils have a large antimicrobial spectrum against bacteria, yeasts and molds. However, Gram negative bacteria are less sensitive to the antimicrobial activity of essential oils due to the lipopolysaccharide outer membrane of this group, which restricts diffusion of hydrophobic compounds. Essential oil of oregano (Origanum vulgare) is widely used as a flavoring component in pizzas, lasagnas and sauces, and can be effective against pathogenic bacteria. Sage oil (Salvia lavandulaefolia) is used in food industry, and pharmaceutical receipts. Rosemary (Rosmarinus officinalis) has been used in food as a flavoring, antioxidant, antiseptic and preservative to prevent the attack of fungi and other microorganisms. An emulsion is a colloidal dispersion composed of two immiscible liquids (usually oil in water) where one liquid is dispersed in another in the form of small spherical droplets. To improve the quality of procedures using essential oils, we use solvents, detergents or emulsifiers agents such as Tween 80, in order to facilitate their dispersion on culture medium. The aim of this study was to evaluate the antimicrobial effect of three essential oils, already referred, against one yeast (Yarrowia lipolytica), one Gram negative bacteria (Pseudomonas aeruginosa) and one Gram positive bacteria (Listeria monocytogenes), in order to appreciate their possible application on salads to control the microbial flora. In this work the dilution method in liquid medium was used, and the antimicrobial activity was determined by counting the viable colonies in agar. V Yarrowia lipolytica showed the best results since its minimum bactericidal concentration was 0.235% (v/v) for Origanum vulgare and 6.336% (v/v) for Salvia lavandulaefolia. As the minimum inhibitory concentration of Rosmarinus officinalis was already relatively high (5.625% (v/v)), its minimum bacterium concentration was only tested until 22.5% (v/v). Pseudomonas aeruginosa proved to be the less sensitive microorganism to the antimicrobial effect of essential oils. Its minimum inhibitory concentration was too high to be used in salads and it was only checked for the Origanum vulgare oil, but just to 0.12% (v/v) with no antimicrobial effect shown. Listeria monocytogenes showed good results with Rosmarinus officinalis oil, and its minimum bactericidal concentration was 3.75% (v/v). Values about 0.051% (v/v) for Origanum vulgare showed no antimicrobial effect against this microorganism

Bactérias Gram-negativas não fermentadoras são frequentemente encontradas em águas superficiais, sendo muitas vezes carregadoras de múltipla resistência. O presente trabalho teve como objetivo principal analisar a participação de Pseudomonas sp. e Acinetobacter sp. na manutenção da resistência a antimicrobianos em quatro pontos na laguna de Tramandaí e se a presença deles poderia contribuir para a sua permanência. As amostras de água superficial foram coletadas em quatro pontos de coleta na laguna e submetidas a tratamento com os antimicrobianos: ácido nalidíxico, ceftazidima, imipenem e tetraciclina na concentração de 20mg/L. Em cada ponto de coleta uma das alíquotas não foi suplementada com os mesmos sendo utilizada como controle. Os isolados de Pseudomonas sp. foram identificados por provas bioquímicas e MALDI-TOF MS, enquanto que os isolados de Acinetobacter sp. somente por provas bioquímicas. O perfil de suscetibilidade de ambos foi avaliado pela técnica de disco-difusão e a produção de ESBL pela técnica de disco combinado. Os pontos 3 e 4 foram os que exibiram maior número de isolados resistentes. Os maiores percentuais de resistência estiveram associados às amostras submetidas ao tratamento com antimicrobianos. Em todos os pontos de coleta foram encontrados isolados de P. aeruginosa e Acinetobacter sp. multirresistentes. Ambas amostras (com e sem tratamento) exibiram diferentes padrões de resistência nos diferentes pontos de coleta e tanto isolados de P. aeruginosa como de Acinetobacter sp. exibiram isolados produtores de ESBL. A presença de P. aeruginosa e Acinetobacter sp. multirresistentes na Laguna de Tramandaí atenta para o risco de disseminação de resistência neste ambiente e que o mesmo pode estar atuando como reservatório de resistência. | Non-fermenting Gram-negative bacteria are often found in surface water, and are often carriers of multiple resistance to antimicrobials. The present work had as main objective to analyze the role of Pseudomonas sp. and Acinetobacter sp. in maintaining antimicrobial resistance at four points in the Tramandaí lagoon. The surface water samples were collected at four sampling points in the lagoon and treated with the antimicrobials: nalidixic acid, ceftazidime, imipenem and tetracycline at a concentration of 20mg/L. At each collection point, one of the aliquots was not supplemented with the antimicrobial and were used as the control for the treatment. The isolates of Pseudomonas sp. were identified by biochemical tests and MALDITOF MS, whereas the isolates of Acinetobacter sp. were identified only by biochemical tests. The susceptibility profile of both was evaluated by the disc diffusion method and the ESBL production by the combined disk method. Sampling points 3 and 4 showed the highest number of resistant isolates. The highest percentages of resistance were associated with the samples that were submitted to antimicrobial treatment. In all sampling points, multiresistant P. aeruginosa and Acinetobacter were isolated. Both samples (with and without treatment) showed different resistance patterns within the sampling points. P. aeruginosa and Acinetobacter sp. isolates exhibited ESBL producers. The presence of multiresistant P. aeruginosa and Acinetobacter sp. in the Tramandaí Lagoon attempted to the risk of spreading resistance in the aquatic environment, since it can act as a reservoir of resistance.

RESUMEN Las plantas purificadoras de agua que carecen de un adecuado sistema de control de calidad pueden generar problemas de salud pública. El objetivo de este estudio fue examinar la calidad microbiológica del agua proveniente de pequeñas plantas purificadoras de la ciudad de Puebla, así como, determinar la existencia de bacterias Aeromonas sp y Pseudomonas sp, y caracterizar si presentan un fenotipo patógeno oportunista. Se recolectaron 70 muestras de garrafones de agua de 25 establecimientos. La cuantificación bacteriana se realizó mediante el método de goteo en placa. Se comprobaron los géneros microbianos mediante análisis bioquímico. En las cepas que mostraron discrepancia se utilizó la identificación molecular con base a secuencias parciales del gen 16S rRNA para confirmar su especie y se les evaluaron sus características de patogenicidad: multirresistencia a antibióticos, producción de biopelícula y actividad hemolítica. El 40 % de las plantas purificadoras no cumplieron con la calidad microbiológica del agua para consumo humano. El 41.4 % de los garrafones de agua muestreados incumplió la normativa, presentando coliformes totales 35.7 %, Pseudomonas 30 %, Enterococcus faecalis 8.6 % y bacterias coliformes fecales el 5.7 %. Se obtuvieron 56 aislados, provenientes de los 29 garrafones contaminados; 10 de ellos se caracterizaron molecularmente, resultando 7 aislados relacionados con especies diferentes de P. aeruginosa y 3 con especies de Aeromonas. De los aislados de Pseudomonas, 5 presentaron resistencia a 2 familias de antibióticos y 2 mostraron multirresistencia. El 36 % de los 10 aislados produjeron hemólisis y biopelícula. Dos cepas de Aeromonas mostraron resistencia a Cefalosporina 3a generación pero no produjeron hemólisis. Los 10 aislados analizados fueron clasificados como no patógenos. Es necesario un seguimiento sanitario más estricto para lograr el cumplimiento de las normas nacionales e internacionales relacionadas con el consumo de agua purificada, para evitar dañar la salud de los consumidores.

RESUMEN Las plantas purificadoras de agua que carecen de un adecuado sistema de control de calidad pueden generar problemas de salud pública. El objetivo de este estudio fue examinar la calidad microbiológica del agua proveniente de pequeñas plantas purificadoras de la ciudad de Puebla, así como, determinar la existencia de bacterias Aeromonas sp y Pseudomonas sp, y caracterizar si presentan un fenotipo patógeno oportunista. Se recolectaron 70 muestras de garrafones de agua de 25 establecimientos. La cuantificación bacteriana se realizó mediante el método de goteo en placa. Se comprobaron los géneros microbianos mediante análisis bioquímico. En las cepas que mostraron discrepancia se utilizó la identificación molecular con base a secuencias parciales del gen 16S rRNA para confirmar su especie y se les evaluaron sus características de patogenicidad: multirresistencia a antibióticos, producción de biopelícula y actividad hemolítica. El 40 % de las plantas purificadoras no cumplieron con la calidad microbiológica del agua para consumo humano. El 41.4 % de los garrafones de agua muestreados incumplió la normativa, presentando coliformes totales 35.7 %, Pseudomonas 30 %, Enterococcus faecalis 8.6 % y bacterias coliformes fecales el 5.7 %. Se obtuvieron 56 aislados, provenientes de los 29 garrafones contaminados; 10 de ellos se caracterizaron molecularmente, resultando 7 aislados relacionados con especies diferentes de P. aeruginosa y 3 con especies de Aeromonas. De los aislados de Pseudomonas, 5 presentaron resistencia a 2 familias de antibióticos y 2 mostraron multirresistencia. El 36 % de los 10 aislados produjeron hemólisis y biopelícula. Dos cepas de Aeromonas mostraron resistencia a Cefalosporina 3a generación pero no produjeron hemólisis. Los 10 aislados analizados fueron clasificados como no patógenos. Es necesario un seguimiento sanitario más estricto para lograr el cumplimiento de las normas nacionales e internacionales relacionadas con el consumo de agua purificada, para evitar dañar la salud de los consumidores. | ABSTRACT Water purification establishments that lack an adequate quality control system can cause public health problems. The objective of this study was to examine the microbiological quality of water from small purification establishments in the city of Puebla, as well as to determine the existence of Aeromonas sp and Pseudomonas sp bacteria, and to characterize whether they present an opportunistic pathogenic phenotype. 70 water jug samples were collected from 25 establishments. Bacterial quantification was performed using the drop plate method. Microbial genera were determined by biochemical analysis using the standard methodology. In the strains that showed discrepancy, molecular identification based on partial sequences of the 16S rRNA gene was used to confirm their species, and their pathogenic characteristics were evaluated: multiresistance to antibiotics, biofilm production, and hemolytic activity. The results showed that 40 % of the purification establishments did not comply with the microbiological quality of water for human consumption. Similarly, 41.4 % of the jugs of water sampled failed to comply with the regulations, presenting total coliforms 35.7 %, Pseudomonas 30 %, Enterococcus faecalis 8.6 % and fecal coliform bacteria 5.7 %. Likewise, 56 isolates were obtained from the 29 contaminated jugs, of which 10 were molecularly characterized, resulting in 4 different species for P. aeruginosa and 3 for Aeromonas. Of the 7 Pseudomonas isolates, 5 presented resistance to 2 families of antibiotics and 2 showed multiresistance. In total, 36 % of the 10 isolates produced hemolysis and biofilm. Two Aeromonas strains showed resistance to 3rd generation Cephalosporin but did not produce hemolysis. The 10 isolates analyzed were classified as non-pathogenic. A stricter sanitary monitoring is necessary to achieve compliance with national and international standards related to the consumption of purified water, to avoid harming the health of consumers.

El trabajo está estructurado en dos partes. La primera tiene como objetivo principal determinar la calidad de un parámetro microbiológico del agua de mesa envasada, de marcas comerciales inscriptas y habilitadas para su envasado en la ciudad de Corrientes y posterior expendio, en cuanto a contaminaciones con Pseudomonas earuginosa. Se trata de una investigación científica con carácter empírico. Se realizó a través del método de tubos múltiples y filtración por membrana en el cual se determinó como muestra 6 marcas comerciales que proveen agua embotellada de 20 litros a distintos establecimientos de la ciudad de Corrientes, tomándose de ellas 72 muestras de 350 ml cada una. Se obtuvo como resultado, la presencia de Pseudomonas aeruginosa en solo una de las 72 muestras analizadas, concluyendo que al haberse presentado una muestra positiva a Pseudomonas aeruginosa. A diferencia de lo hallado por otros autores y en diferentes regiones podemos señalar que el agua envasada en la Ciudad de Corrientes cumple con las normas de potabilidad. Para asegurar la calidad del producto resulta indispensable el monitoreo del agua empleada como materia prima, sanitización de equipos y contenedores a fin de obtener un producto que se ajusta a los estándares microbiológicos exigidos por la reglamentación Argentina. En la segunda parte se realiza un análisis metodológico del trabajo realizado en la primera parte. Se describe la estructura e importancia de la construcción de un objeto de investigación, las decisiones tomadas respecto a los procedimientos, el análisis y la publicación de los resultados. Se realiza la descripción teórica y empírica del objeto Pseudomonas earuginosa en un proceso que va del análisis y operacionalización del objeto a la síntesis y vuelta a reconstituir la totalidad.