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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Efeito da aspersão de água sobre a contaminação microbiológica em esteiras transportadoras de cortes de frango / Effect of woater spray on microbiological contamination in conveyor belts of chicken cuts

Soares, Vanessa Mendonça [UNESP] 28 July 2014 (has links) (PDF)
Made available in DSpace on 2015-05-14T16:53:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-07-28Bitstream added on 2015-05-14T16:59:07Z : No. of bitstreams: 1 000829480.pdf: 377403 bytes, checksum: 7e92763aaee8428dce85038b17519dfb (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O presente estudo teve como objetivo avaliar o efeito do uso de aspersão de água como forma de higiene operacional em esteiras sanitárias condutoras de cortes de frango em quatro linhas de processamento. Em cada linha de processamento, foram coletadas amostras de dois tipos de esteiras (modular e lisa) higienizadas com água e não higienizadas, em quatro tempos distintos (T0, T1, T2 e T3). As amostras foram submetidas à contagem de mesófilos, enterobactérias e pesquisa de L. monocytogenes. Culturas de L. monocytogenes foram submetidas à sorotipagem e a PFGE. Foram realizadas dez repetições do experimento em cada linha de processamento. Com base nos resultados foi possível observar que o efeito da utilização da aspersão com água foi dependente de diversos fatores, tais como a linha de processamento, tipo de corte, design do equipamento e o tipo de esteira. A higienização por aspersão não foi o fator primordial para garantir a eliminação de L. monocytogenes, uma vez que o patógeno foi isolado independente da linha de processamento e tipo de esteira, além disso, os pulsotipos encontrados evidenciaram a disseminação do patógeno nas linhas de processamento avaliadas. Deste modo, a decisão de retirar a água do processo de higienização de esteiras condutoras deve ser precedida de um estudo criterioso para garantir que a sua ausência não venha influenciar na inocuidade dos produtos de origem animal / This study aimed to evaluate the effect of the use of water spray on cleaning of conveyor belts in four broiler lines processing in Brazilian slaughterhouses. Surface samples were collected of two types of conveyor belt (modular and smooth) which passed through two processes (with and without water spray), in four times (T0, T1, T2 and T3). The samples were subjected to mesophilic and enterobacteria count, and research of L. monocytogenes. Cultures of L. monocytogenes were serotyped and submitted to PFGE. Ten replicates of the experiment were performed on each processing line. The results demonstrated that the effect of the use of spraying with water was dependent on several factors, such as the processing line, product type, equipment design and the type of conveyor belt. The cleaning spray is not the primary factor in ensuring the elimination of L. monocytogenes, because the pathogen was isolated independent of the type of conveyor belt and processing line, moreover, PFGE demonstrated the dissemination in the processing lines. Thus, the decision to remove the water from the cleaning of conveyor belts must be preceded by a study to ensure that the absence of this procedure does not influence the safety of products of animal origin
2

Efeito da aspersão de água sobre a contaminação microbiológica em esteiras transportadoras de cortes de frango /

Soares, Vanessa Mendonça. January 2014 (has links)
Orientador: José Paes de Almeida Nogueira Pinto / Banca: Luciano dos Santos Bersot / Banca: Luís Augusto Nero / Banca: Maria Teresa Destro / Banca: Vera Lúcia Mores Rall / Resumo: O presente estudo teve como objetivo avaliar o efeito do uso de aspersão de água como forma de higiene operacional em esteiras sanitárias condutoras de cortes de frango em quatro linhas de processamento. Em cada linha de processamento, foram coletadas amostras de dois tipos de esteiras (modular e lisa) higienizadas com água e não higienizadas, em quatro tempos distintos (T0, T1, T2 e T3). As amostras foram submetidas à contagem de mesófilos, enterobactérias e pesquisa de L. monocytogenes. Culturas de L. monocytogenes foram submetidas à sorotipagem e a PFGE. Foram realizadas dez repetições do experimento em cada linha de processamento. Com base nos resultados foi possível observar que o efeito da utilização da aspersão com água foi dependente de diversos fatores, tais como a linha de processamento, tipo de corte, design do equipamento e o tipo de esteira. A higienização por aspersão não foi o fator primordial para garantir a eliminação de L. monocytogenes, uma vez que o patógeno foi isolado independente da linha de processamento e tipo de esteira, além disso, os pulsotipos encontrados evidenciaram a disseminação do patógeno nas linhas de processamento avaliadas. Deste modo, a decisão de retirar a água do processo de higienização de esteiras condutoras deve ser precedida de um estudo criterioso para garantir que a sua ausência não venha influenciar na inocuidade dos produtos de origem animal / Abstract: This study aimed to evaluate the effect of the use of water spray on cleaning of conveyor belts in four broiler lines processing in Brazilian slaughterhouses. Surface samples were collected of two types of conveyor belt (modular and smooth) which passed through two processes (with and without water spray), in four times (T0, T1, T2 and T3). The samples were subjected to mesophilic and enterobacteria count, and research of L. monocytogenes. Cultures of L. monocytogenes were serotyped and submitted to PFGE. Ten replicates of the experiment were performed on each processing line. The results demonstrated that the effect of the use of spraying with water was dependent on several factors, such as the processing line, product type, equipment design and the type of conveyor belt. The cleaning spray is not the primary factor in ensuring the elimination of L. monocytogenes, because the pathogen was isolated independent of the type of conveyor belt and processing line, moreover, PFGE demonstrated the dissemination in the processing lines. Thus, the decision to remove the water from the cleaning of conveyor belts must be preceded by a study to ensure that the absence of this procedure does not influence the safety of products of animal origin / Doutor
3

Modulation of the immune system in the mammalian intestine as an alternate explanation for the action of antimicrobial growth promoters / Estela Costa

Costa, Estela, University of Lethbridge. Faculty of Arts and Science January 2010 (has links)
The novel hypothesis that antimicrobial growth promoters (AGP) function by modulating the mammalian immune system was tested. Sampling methods to characterize the mucosa-associated microbiota of the murine intestine by terminal restriction fragment length polymorphism (T-RFLP) analysis indicated that direct plug extraction was superior to wash methods. Using T-RFLP analysis, non-therapeutic administration of chlortetracycline (CTC) and sulfamethazine to beef cattle did not affect the composition of bacterial communities associated with intestinal mucosa and in digesta, with exception of those associated with mucosa of the proximal jejunum. Similarly, oral administration of non-therapeutic concentrations of CTC did not affect the mucosa-associated microbiota of the murine intestine. Oral administration of nontherapeutic concentrations of CTC prevented weight loss, reduced pathologic changes, modulated transcription levels of inflammatory cytokines in C. rodentium-infected mice, and did not consistently affect the colonic microbiota. These findings support the hypothesis that AGP primarily function by modulating the intestinal immune system. / xiv, 160 leaves ; 29 cm
4

Dispersive liquid-liquid micro-extraction of Chloramphenicol and its congeners residues in water, meat and milk followed by electron spray ionisation liquid chromaotgraphy tandem mass spectrometry detection

Kemokgatla, Ompelege E. 10 1900 (has links)
The use of veterinary drugs continues to be a challenge since some farmers use drugs for medicinal purposes, while others use them as growth promoters without observing the set withdrawal times. In emerging economies, challenges are experienced in residue testing to ensure residue free animal products. It is therefore necessary to develop a simple, environmentally friendly and cost effective extraction method for veterinary drugs residues. A dispersive liquid-liquid micro-extraction method for simultaneous determination of chloramphenicol, florfenicol and thiamphenicol residues in water, bovine muscle and milk was developed optimised and validated. Analysis was performed with liquid chromatography coupled to electron spray ionization tandem mass spectrometry in negative ion multiple reaction monitoring mode. Dispersive liquid-liquid micro-extraction method development involved optimisation of parameters such as type and volume of extraction solvent, type and volume of disperser solvent and pH. The optimum extraction solvent was dichloromethane at a volume of 250 μL while the optimum disperser solvent was acetonitrile (1 mL) Extraction was found to be optimum at pH 7. The developed method was validated according to Commission decision 2002/657/EC. Linearity. Linearity was observed for water, bovine milk and muscle in the ranges of 0.3 μg kg-1 to 0.9 μg kg-1, 25 μg kg-1 to 100 μg kg-1 and 50 μg kg-1 to 200 μg kg-1 for chloramphenicol, thiamphenicol and florfenicol respectively with regression coefficients ranging between 0.9941 and 0.9999. Limit of detections for CAP, FFC & THAP were 0.082, 3.31, and 2.21 μg kg-1 respectively while Limit of quantifications were 0.163, 7.51 and 6.84 μg kg-1 respectively. The recoveries for water, bovine milk and bovine muscle ranged between 87.2% and 102%. In this study the validated dispersive liquid-liquid micro-extraction has been found to perform very well not only in the water matrix but also in the more complex matrices like bovine milk and muscle. / Chemistry / M. Sc. (Chemistry)
5

Monitoramento via PCR de Salmonella spp. no processamento de carne suína

Samulak, Renata Louize 20 February 2013 (has links)
CAPES / A Salmonella spp. é um dos principais micro-organismos patogênicos envolvidos em Doenças Transmitidas por Alimentos (DTA’s), com destaque para surtos envolvendo a ingestão de carne suína. Nesse sentido, o objetivo deste estudo foi avaliar a segurança alimentar na produção de carne suína e embutidos quanto a presença de Salmonella spp. no processo produtivo. As amostras foram coletadas em um frigorífico que abate suínos e fabrica embutidos, localizado na região dos Campos Gerais - PR. Inicialmente, para padronização da PCR foi necessário determinar um protocolo de extração, bem como, ajustes metodológicos para amplificação de DNA. Para esses testes realizados, foi utilizada amostra de Salmonella spp previamente isolada de alimento. O protocolo de extração testado foi lise térmica e para reação de amplificação foram avaliadas três concentrações de DNA e diferentes temperaturas de hibridização para estabelecimento do padrão ideal. O protocolo escolhido mostrou-se bastante eficiente para extração do DNA de Salmonella spp, pois permitiu a obtenção de DNA em quantidade e com qualidade suficiente para amplificação de bandas. Para a amplificação, a melhor condição encontrada foi a concentração de DNA de aproximadamente 40 ng e uma temperatura de hibridização de57 ºC.Com o intuito de validar a análise molecular via PCR, realizouse um estudo comparativo inicial com a microbiologia convencional para comprovação dos resultados obtidos pela análise molecular. Inicialmente foram escolhidos dezessete pontos durante as diferentes etapas do processo produtivo do frigorífico em estudo. Duas carcaças foram acompanhadas durante todo o processo e amostras foram coletadas, contemplando desde a etapa de escaldagem até o embutimento do produto final. A utilização da técnica de PCR mostrou-se vantajosa nos seguintes aspectos: tempo de análise total de aproximadamente 30 horas; maior sensibilidade comparado ao método convencional. Decorrida a validação, foi realizada nova coleta, contemplando etapas desde pré-abate até a obtenção do embutido, perfazendo um total de 62 amostras, com intuito de avaliar contaminação durante a produção de carne suína e embutidos. Como resultado, foi verificado que 60% das amostras estavam contaminadas por Salmonella spp, em diversas etapas do processo produtivo. A partir dessa avaliação, foram selecionados alguns pontos contaminados e elaborado um plano de ações corretivas, a fim de controlar e diminuir os perigos microbiológicos existentes no local. Através de novas análises via PCR foi possível verificar que o plano de ações foi eficiente em 100% das amostras. / The Salmonella spp is major pathogens involved in Food borne Diseases (FBD), especially outbreaks involving the ingestion of meet and this products. The aim of this study was to evaluate the food safety in pork and sausages production for the Salmonella spp. presence in the process. The samples were collected in a refrigerator that slaughter pigs and manufactures sausages, located in the Campos Gerais - PR. Initially, to standardize the PCR was necessary to determine an extraction protocol, as well as methodological adjustments to the PCR reaction. For these tests it was used sample of Salmonella isolated from food. The extraction protocol was tested by heating process and for amplification reaction were evaluated three different concentration of DNA and hybridization temperatures to establish the ideal standard. The chosen protocol proved to be very efficient for the Salmonella ssp DNA extraction because it allowed obtaining DNA in sufficient quality and quantity for amplification bands. For amplification, the best condition was found a concentration of approximately 40 ng DNA and a hybridization temperature of 57 ° C. In order to validate the molecular analysis by PCR, we carried out a comparative study with the initial conventional microbiology for proof of all results obtained by molecular analysis. Seventeen points were chosen during the different stages of production process. Two carcasses were monitored throughout the procedure and samples were collected, comprising the scalding step to the final product inlay. The PCR usage technique proved advantageous in the following aspects: total analysis time of approximately 30 hours; higher sensitivity compared to conventional. After validation, we performed a new collection, covering stages from pre-slaughter until embedded obtaining, making a total of 62 samples, in order to assess contamination during production of pork and sausages. As a result, it was found that 60% of the samples were contaminated with Salmonella spp, in various stages of production. From this evaluation, we selected some points contaminated and developed a corrective action plan in order to control and reduce microbiological hazards on the premises. Through further analysis by PCR was possible to verify that the action plan was effective in 100% of samples.

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