Made available in DSpace on 2014-06-11T19:23:01Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-12-02Bitstream added on 2014-06-13T20:29:37Z : No. of bitstreams: 1 oliveira_dcv_me_botib.pdf: 990055 bytes, checksum: 07196c8f0c321ad972ef51db39060685 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Bactérias do gênero Salmonella estão entre as principais causas de enfermidades transmitidas por alimentos (ETA), sendo que os de origem animal são os maiores responsáveis pela veiculação desse micro-organismo, principalmente frangos que são portadores assintomáticos de alguns sorotipos patogênicos para o homem. A Instrução Normativa n° 70 (2003), do Programa de Redução de Patógenos do Ministério da Agricultura e Abastecimento confere um controle minucioso sobre o processo de abate, garantindo a higiene correta dos alimentos e sua segurança em todos os estágios da produção. Porém, a presença de micro-organismos formadores de biofilmes nas indústrias de alimentos, como a Salmonella, é motivo de preocupação pelas falhas que podem ocorrer no processo de higienização. As propriedades físico-químicas de uma superfície podem exercer influência sobre a adesão dos micro-organismos, os quais aderem mais facilmente às superfícies hidrofóbicas (PVCs) do que às hidrofílicas (vidro ou metais como aço inox). Assim como outras bactérias patogênicas, as salmonelas possuem fímbrias e produzem celulose, que vão influenciar na sua adesão às superfícies e estão entre os principais componentes da matriz em biofilmes. Os genes agf (agregative fímbrias) estão envolvidos na biossíntese de fímbrias, enquanto o segundo componente, a celulose, é produzida pelos genes bcsA, bcsB, bcsZ e bcsC (síntese de celulose bacteriana). A produção de fímbrias, co-regulada pelo regulador tipo LuxR, o agfD, vai regular indiretamente a produção de celulose atuando no gene adrA. A expressão dos dois componentes leva à formação dessa matriz. Sendo assim, o presente trabalho teve por objetivo a pesquisa da presença desses genes nas cepas de Salmonella sp., isoladas de frango e o comportamento dessas cepas quanto à produção... / Bacteria of the genus Salmonella are among the leading causes of foodborne disease (FBD), being, those from animals, the most responsibles for placement this microorganism, especially poultry that are asymptomatic carriers of some serotypes pathogenic to humans. Normative Instruction No. 70 (2003), of the Pathogen Reduction Program of the Ministry of Agriculture and Supply gives rigorous control over the slaughter process, ensuring proper food hygiene and safety in all stages of production. However, the presence of microorganisms forming biofilms in the food, such as Salmonella, is a cause of concern due to the failures that may occur in the process of cleaning. The physicochemical properties of a surface can influence the adhesion of microorganisms, which adhere more readily to hydrophobic surfaces (PVCs) than to hydrophilic (glass or metals such as stainless steel). Like other pathogenic bacteria, Salmonella possess fimbriae and produces cellulose, which will affect their adherence to surfaces and are among the main components of the matrix in biofilms. Genes agf (agregative fimbriae) are involved in the biosynthesis of fimbriae, while the second component, cellulose, is produced by genes bcsA, bcsB, bcsZ and bcsC (bacterial cellulose synthesis). The production of fimbriae, co-regulated by LuxR type regulator, the agfD, will regulate the production of cellulose indirectly acting on the gene adrA. The expression of these two components leads to the formation of this matrix. Therefore, this study aimed to research the presence of these genes in strains of Salmonella isolated from poultry and the behavior of these strains for the production of biofilm at different temperatures (16º, 20º, 28º and 35ºC) and materials (glass, PVC and stainless steel) as well as the analysis of the characteristic morphology expressed at 28°C, optimum temperature for the production of biofilm

Salmonella has been studied and researched for more than a hundred years and yet it remains a problem for human and animal health. The goal of this dissertation was to apply the systems thinking approach to Salmonella contamination and develop a System Dynamics (SD) simulation model for Salmonella contamination in the chill tank of a poultry processing plant. But first the appropriate carcass rinse sampling method that would not impact on the resulting Salmonella contamination status of the broiler carcass was studied. Kappa agreement analysis was used to evaluate three sampling methods. The adjacent rinse method was found to be the best method. In the absence of actual data, literature data was used to develop a literature-based SD simulation model of Salmonella contamination of broiler carcasses in the chill tank. The literature-based SD model is the first application of system dynamics simulation modeling in the poultry-processing field. The model was able to show and simulate the dynamic and non-linear interrelationships between parameters, namely pH, chlorine (Cl) level, water flow and turbidity. Actual data collection was done using a specially designed apparatus that recorded the time, temperature, pH, chlorine, water flow and turbidity in the chill tank as carcass rinse samples were collected. Linear regression analysis was used to identify the statistically significant models for relationships between the parameters in the chill tank. Finally, the data was analyzed using logistic regression to determine the association between the parameters in the chill tank and the occurrence of Salmonellaa in carcasses exiting the chill tank. These results were used to develop a data-based SD model. The data-based model was then validated using the validity tests proposed by various authors for SD simulation models and found to be a valid model. The developed model offers a fresh perspective to the problem of Salmonella contamination- to view it as a system of factors that are interrelated and have a feedback mechanism, rather than the traditional concept of linear causation. The developed model is a powerful cost efficient tool for testing interventions for reducing Salmonella contamination in the poultry processing plant.

Orientador: Vera Lúcia Mores Rall / Banca: Ary Fernandes Junior / Banca: José Paes de Almeida Nogueira Pinto / Resumo: Bactérias do gênero Salmonella estão entre as principais causas de enfermidades transmitidas por alimentos (ETA), sendo que os de origem animal são os maiores responsáveis pela veiculação desse micro-organismo, principalmente frangos que são portadores assintomáticos de alguns sorotipos patogênicos para o homem. A Instrução Normativa n° 70 (2003), do Programa de Redução de Patógenos do Ministério da Agricultura e Abastecimento confere um controle minucioso sobre o processo de abate, garantindo a higiene correta dos alimentos e sua segurança em todos os estágios da produção. Porém, a presença de micro-organismos formadores de biofilmes nas indústrias de alimentos, como a Salmonella, é motivo de preocupação pelas falhas que podem ocorrer no processo de higienização. As propriedades físico-químicas de uma superfície podem exercer influência sobre a adesão dos micro-organismos, os quais aderem mais facilmente às superfícies hidrofóbicas (PVCs) do que às hidrofílicas (vidro ou metais como aço inox). Assim como outras bactérias patogênicas, as salmonelas possuem fímbrias e produzem celulose, que vão influenciar na sua adesão às superfícies e estão entre os principais componentes da matriz em biofilmes. Os genes agf (agregative fímbrias) estão envolvidos na biossíntese de fímbrias, enquanto o segundo componente, a celulose, é produzida pelos genes bcsA, bcsB, bcsZ e bcsC (síntese de celulose bacteriana). A produção de fímbrias, co-regulada pelo regulador tipo LuxR, o agfD, vai regular indiretamente a produção de celulose atuando no gene adrA. A expressão dos dois componentes leva à formação dessa matriz. Sendo assim, o presente trabalho teve por objetivo a pesquisa da presença desses genes nas cepas de Salmonella sp., isoladas de frango e o comportamento dessas cepas quanto à produção... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Bacteria of the genus Salmonella are among the leading causes of foodborne disease (FBD), being, those from animals, the most responsibles for placement this microorganism, especially poultry that are asymptomatic carriers of some serotypes pathogenic to humans. Normative Instruction No. 70 (2003), of the Pathogen Reduction Program of the Ministry of Agriculture and Supply gives rigorous control over the slaughter process, ensuring proper food hygiene and safety in all stages of production. However, the presence of microorganisms forming biofilms in the food, such as Salmonella, is a cause of concern due to the failures that may occur in the process of cleaning. The physicochemical properties of a surface can influence the adhesion of microorganisms, which adhere more readily to hydrophobic surfaces (PVCs) than to hydrophilic (glass or metals such as stainless steel). Like other pathogenic bacteria, Salmonella possess fimbriae and produces cellulose, which will affect their adherence to surfaces and are among the main components of the matrix in biofilms. Genes agf (agregative fimbriae) are involved in the biosynthesis of fimbriae, while the second component, cellulose, is produced by genes bcsA, bcsB, bcsZ and bcsC (bacterial cellulose synthesis). The production of fimbriae, co-regulated by LuxR type regulator, the agfD, will regulate the production of cellulose indirectly acting on the gene adrA. The expression of these two components leads to the formation of this matrix. Therefore, this study aimed to research the presence of these genes in strains of Salmonella isolated from poultry and the behavior of these strains for the production of biofilm at different temperatures (16º, 20º, 28º and 35ºC) and materials (glass, PVC and stainless steel) as well as the analysis of the characteristic morphology expressed at 28°C, optimum temperature for the production of biofilm / Mestre