Investigação da presença e da formação de biofilmes por estafilococos em micro-usina de beneficiamento de leite
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Data
2009-07-14
Autores
Santos, Suzy Sviech dos [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O leite é um alimento altamente nutritivo e excelente substrato para a multiplicação de microrganismos. Os estafilococos estão entre os principais contaminantes do leite, seja em decorrência da mastite ou de falhas de higienização. A contaminação do leite pode favorecer a adesão bacteriana sobre superfícies com a formação de biofilmes, cujos fragmentos podem se desprender e contaminar o produto durante o processo de beneficiamento, o que representa um risco à saúde do consumidor. Tendo isto em foco, objetivou-se o presente estudo, em uma micro-usina do Estado de São Paulo, a fim de investigar a presença e formação de biofilme por Staphylococcus spp, antes e após o processo de higienização. Colheu-se o total de 60 amostras por meio de suabes, antes e após o processo de higienização, das superfícies do tanque de recepção, do tanque de estocagem de leite cru, da tubulação de saída do pasteurizador, do tanque de estocagem de leite pasteurizado, e da tubulação da máquina de envase. Foram colhidas, ainda, amostras de leite no tanque de recepção, no tanque de estocagem de leite cru, na tubulação de saída do pasteurizador e amostras de leite envasado, assim como das embalagens plásticas vedadas e vazias, utilizadas para o envase do leite pasteurizado. Dentre 41 estirpes de Staphylococcus spp isoladas, 16 (39,0%) mostraram-se positivas na prova da coagulase, enquanto que 25 (61,0%) foram negativas. Por meio de análise genotípica, com a técnica de Reação em Cadeia da Polimerase (PCR), pode-se observar que, dentre as 16 estirpes coagulase positivas, quatro (25%) apresentavam o gene icaA e 16 (100%) possuíam o gene icaD. Dentre as 25 estirpes coagulase negativas, 11 (44%) possuíam o gene icaA e 25 (100%) possuíam o gene icaD. Visualizou-se, por meio da microscopia eletrônica de varredura...
Milk is a highly nutritious food and excellent substrate for the multiplication of microorganisms. Staphylococci are one of the major contaminants of milk whether due to mastitis or hygiene failures in cleaning. Milk contamination may encourage bacterial adherence on surfaces with the formation of biofilms, whose fragments can detach and contaminate the product during beneficial processing, which represents a health risk to the consumers. With this in focus as the objective of this present study, to investigate the presence and formation of biofilm of Staphylococcus spp before and after the cleaning process in a micro-dairy plant in São Paulo State. A total of 60 swab samples were collected before and after the cleaning process from the reception tank surfaces, the raw milk storage tank storage, the pasteurizer outlet pipe, the pasteurized milk storage tank, and the filling machine. Further samples were collected of the milk in the receiving tank, the raw milk storage tank, from the pasteurizer outlet pipe, and packaged milk, as well as the empty sealed plastic packaging used for packaging the pasteurized milk. Of the 41 strains of isolated Staphylococcus spp, 16 (39.0%) indicated positive in the coagulase test, while 25 (61.0%) were negative. Through genetic analysis, using the Polymerase Chain Reaction (PCR) technique, it was observed that within the 16 strains of coagulase-positive, four (25%) presented the gene icaA and 16 (100%) had the gene icaD. Of the 25 strains of coagulase-negative, 11 (44%) had the gene icaA and 25 (100%) had the gene icaD. It was seen using a scanning electron microscope the start of bacteria adhesion and the formation of biofilm for all the isolated strains. From the obtained results it was possible to see evidence to the potential risk to the health of the consumer represented... (Complete abstract click electronic access below)
Milk is a highly nutritious food and excellent substrate for the multiplication of microorganisms. Staphylococci are one of the major contaminants of milk whether due to mastitis or hygiene failures in cleaning. Milk contamination may encourage bacterial adherence on surfaces with the formation of biofilms, whose fragments can detach and contaminate the product during beneficial processing, which represents a health risk to the consumers. With this in focus as the objective of this present study, to investigate the presence and formation of biofilm of Staphylococcus spp before and after the cleaning process in a micro-dairy plant in São Paulo State. A total of 60 swab samples were collected before and after the cleaning process from the reception tank surfaces, the raw milk storage tank storage, the pasteurizer outlet pipe, the pasteurized milk storage tank, and the filling machine. Further samples were collected of the milk in the receiving tank, the raw milk storage tank, from the pasteurizer outlet pipe, and packaged milk, as well as the empty sealed plastic packaging used for packaging the pasteurized milk. Of the 41 strains of isolated Staphylococcus spp, 16 (39.0%) indicated positive in the coagulase test, while 25 (61.0%) were negative. Through genetic analysis, using the Polymerase Chain Reaction (PCR) technique, it was observed that within the 16 strains of coagulase-positive, four (25%) presented the gene icaA and 16 (100%) had the gene icaD. Of the 25 strains of coagulase-negative, 11 (44%) had the gene icaA and 25 (100%) had the gene icaD. It was seen using a scanning electron microscope the start of bacteria adhesion and the formation of biofilm for all the isolated strains. From the obtained results it was possible to see evidence to the potential risk to the health of the consumer represented... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Leite - Qualidade, Contaminação, Leite - Usina de beneficiamento, Estafilococos, Biofilmes, Bacterial contamination, Genes icaAD, Milk quality, Milk processing dairy, Staphylococcus spp
Como citar
SANTOS, Suzy Sviech dos. Investigação da presença e da formação de biofilmes por estafilococos em micro-usina de beneficiamento de leite. 2009. xv, 57 f. Dissertação (mestrado) - Universidade Estadual Paulista, Faculdade de Ciências Agrárias e Veterinárias, 2009.