Biofilmes são constituídos de bactérias aderidas a uma superfície e aderidas entre si envolvidas por um polissacarídeo de constituição proteica, lipídica e glicídica que conferem uma barreira física às bactérias dentro deste microambiente. O objetivo deste trabalho foi analisar a eficácia do hipoclorito de sódio (NaOCl) contra estirpes de Staphylococcus aureus isoladas de leite cru de vacas com mastite subclínica e Staphylococcus aureus isolados do ambiente de ordenha (borrachas de ordenhadeiras e mangueiras condutoras de leite). Os resultados revelaram que, na presença de hipoclorito de sódio (150ppm), o número de células aderidas das 12 estirpes de S. aureus analisadas foi significativamente reduzido. Quando as mesmas estirpes foram avaliadas em condições de biofilme, diferentes resultados foram obtidos. Verificou-se que, após um período de contato de cinco minutos com NaOCl (150ppm), quatro estirpes (duas estirpes de leite, uma estirpe das borrachas das ordenhadeiras e uma estirpe de uma mangueira condutora de leite) ainda eram capazes de crescer. Com o aumento do tempo de contato do hipoclorito e as bactérias, cada vez maior, na concentração de 150ppm, não foi detectado o crescimento das estirpes. Em relação à eficácia do NaOCl na formação total da biomassa do biofilme por cada uma das estirpes de S. aureus, observou-se decréscimo da biomassa dos biofilmes quando estas estirpes estavam em contato com o NaOCl na concentração de 150ppm durante um tempo total de 10 minutos. O estudo demonstra a importância de um protocolo de saneamento correto de todas as unidades de processamento de leite, que pode, efetivamente, reduzir a presença de microrganismos de forma significativa, conduzindo a uma diminuição da mastite e da contaminação do leite.

Biofilms constitute a physical barrier, protecting the encased bacteria from detergents and sanitizers. The objective of this work was to analyze the effectiveness of sodium hypochlorite (NaOCl) against strains of Staphylococcus aureus isolated from raw milk of cows with subclinical mastitis and Staphylococcus aureus isolated from the milking environment (blowers and milk conducting tubes). The results revealed that, in the presence of NaOCl (150ppm), the number of adhered cells of the twelve S. aureus strains was significantly reduced. When the same strains were evaluated in biofilm condition, different results were obtained. It was found that, after a contact period of five minutes with NaOCl (150ppm), four strains (two strains from milk , one from the blowers and one from a conductive rubber) were still able to grow. Although with the increasing contact time between the bacteria and the NaOCl (150ppm), no growth was detected for any of the strains. Concerning the efficiency of NaOCl on total biofilm biomass formation by each S. aureus strain, a decrease was observed when these strains were in contact with 150 ppm NaOCl for a total period of 10 minutes. This study highlights the importance of a correct sanitation protocol of all the milk processing units which can indeed significantly reduce the presence of microorganisms, leading to a decrease of cow´s mastitis and milk contamination.

Foi realizado o monitoramento epidemiológico molecular de estirpes de Staphylococcus aureus potencialmente toxigênicas isoladas no processo de produção do queijo Minas frescal em micro-usina do Estado de São Paulo. Para tanto, foram realizadas seis amostragens durante o período de junho de 2008 a julho de 2009, de modo a perfazer um total de 140 amostras. Essas amostras foram colhidas da superfície dos tanques de recepção e estocagem do leite cru, da superfície do tanque de equilíbrio do leite pasteurizado, da rede de abastecimento de água, das tubulações e equipamentos, das mãos do manipulador e de queijos embalados prontos para consumo. As colônias isoladas em Agar Baird-Parker confirmadas como cocos Gram positivos e que mostravam-se positivas às provas de catalase, coagulase e da produção de acetoína, foram submetidas à extração do DNA bacteriano através da utilização do Kit Invitek - Uniscience®. A confirmação molecular da espécie dos isolados e a presença de enterotoxinas SEA, SEB, SEC, SED e da toxina TSST-1 foi realizada a partir da amplificação dos fragmentos de DNA cromossômico específico. Entre as 74 estirpes de estafilococos coagulase positivos isoladas, somente 41 (55.4%) amostras foram confirmadas como sendo Staphylococcus aureus, das quais 25 (61,0%) mostraram-se positivas na pesquisa de toxinas estafilocócicas. A enterotoxina de maior frequência identificada foi a SEA. As estirpes de Staphylococcus aureus toxigênico foram mais isoladas nas mãos do manipulador (16,0%), no leite cru do tanque de recepção (12,0%), no leite pasteurizado para elaboração do queijo (12,0%) e no queijo Minas frescal pronto para consumo (12,0%).

We studied the molecular epidemiology of Staphylococcus aureus strains potentially toxigenic, isolated from the production process of Minas frescal cheese in a small dairy plant in the state of São Paulo. For this, samples were taken during the period from June 2008 to July 2009. Samples were collected from the surface of the receiving and storage tanks of raw milk, the surface of the balance tank of pasteurized milk, the water supply system, the pipes and equipments, the hands of the handler and from the packaged cheese, totaling 140 samples. The colonies isolated on Baird-Parker Agar confirmed as Gram positive and positive for catalase, coagulase and acetoin production, were submitted to extraction of bacterial DNA using the Invitek - Uniscience® kit. Confirmation of the isolated species and enterotoxins SEA, SEB, SEC, SED and TSST-1 toxin was carried out through the amplification of specific fragments of chromosomal DNA. Among the 74 strains of isolated coagulase-positive staphylococci, only 41 (55.4%) strains were confirmed as Staphylococcus aureus, of which 25 (61.0%) were positive to the presence of staphylococcal toxins. The most frequently identified enterotoxin was SEA. The toxigenic strains of Staphylococcus aureus were more frequently isolated from hands of the handler (16.0%), raw milk receiving tank (12.0%), pasteurized milk for cheese making (12.0%) and fresh white cheese ready for consumption (12.0%).

Biofilm formation is considered to be a selective advantage for Staphylococcus aureus mastitis isolates by facilitating bacterial persistence in the udder. It requires attachment to mammary epithelium, proliferation and accumulation of cells in multilayers. The objective of this study was to determine the sensitivity and specificity of three techniques for the detection of S. aureus biofilm-positive strains. Two phenotypic tests, including growth on microtitre plates and Congo red agar, were compared with a PCR technique using 94 S. aureus strains obtained from cows with subclinical mastitis from two farms in the state of São Paulo. These strains were characterised by in vitro slime production on Congo red agar, biofilm formation on microtitre plates and the presence of the icaA and icaD genes. The results revealed that 85% of the isolates tested produced slime on the Congo red agar, 98.9% of the isolates produced biofilms in vitro by adhering to sterile 96-well "U" bottom polystyrene tissue culture plates, and 95.7% of the isolates carried the icaA and icaD genes. The results of the phenotypic tests for biofilm formation were compared with those of the molecular analysis, and the sensitivity and specificity of the Congo red agar test were 88.9% and 100%, respectively, while those of the microtitre plate test were 100% and 25%, respectively. When the phenotypic methods for the detection of biofilm producers, namely growth on microtitre plates and Congo red agar, were compared, the sensitivity and specificity were 86% and 100%, respectively. Therefore, growth on Congo red agar and the microtitre plate test are methods that could be used to determine whether an isolate has the potential for biofilm production.

The epidemiological relationships between isolated Staphylococcus aureus strains in milk samples of dairy cows, reagent to California Mastitis Test, individual and group milk was demonstrated in different sites of the production fluxogram, in 12 milk-producing farms in the Gameleira region, municipality of Sacramento MG Brazil, so that localization and transmission modes may be identified. Two hundred and forty-four strains out of 446 samples collected at several sites were isolated and bio-chemically characterized as coagulase-positive staphylococcus. Specific chromosome DNA fragment of the species Staphylococcus aureus was amplified to 106 strains and 103 underwent (PFGE). Samples' collection sites with the highest isolation frequency of Staphylococcus aureus strains comprised papillary ostia (31.1%), CMT-reagent cow milk (21.7%), mechanical milking machines' insufflators (21,7%), milk in milk pails (6.6%) and the milk in community bulk tanks (5.6%). Genetic heterogeneity existed among the isolated 103 Staphylococcus aureus strains, since 32 different pulse-types were identified. Pulse-type 1 had the highest similarity among the isolated strains within the different sites of the milk-production fluxogram. Highest occurrence of pulsetype 1 isolates of Staphylococcus aureus strains was reported in samples collected from the papillary ostia (10.6%), followed by milk samples from CMT-reagent dairy cows (5.8%) and mechanical milking machine insufflators (3.8%). The above shows the relevance of these sites in the agents' transmission mechanism within the context of the farms investigated.

O presente estudo analisa a representação social dos usuários sobre o SUS e o PSF, apresentando dados obtidos por intermédio de entrevistas semiestruturadas, utilizando o referencial teórico da pesquisa qualitativa. Os resultados mostram uma representação social marcada por uma visão focalizada e assistencialista, apontando para a concentração de recursos públicos em segmentos mais pobres da sociedade e centrada no modelo de atenção biomédico. Destaca-se que o PSF não conseguiu alcançar seus objetivos de proporcionar mudanças na práxis em saúde. Em relação ao controle social, observa-se que apenas 5,9% dos entrevistados conhecem o CMS. Os dados apresentados mostram um grande desconhecimento da população estudada sobre o sistema sanitário e os direitos sociais conquistados, sendo que para muitos o SUS ainda é visto como um "plano de saúde para os pobres". Diante da realidade vivenciada, ressalta-se a necessidade da implementação de estratégias para o alcance de maior empoderamento/libertação da população, visando construir possibilidades efetivas para que seus atores sejam participantes ativos do processo de construção de um projeto comum, realmente fundamentado nos ideais democráticos do SUS, sendo o PSF estrategicamente importante na realização dessas ações.

The present study analyzes the representation of the users of SUS and PSF, presenting data obtained by semi-structured interviews, using the theoretical referential of the qualitative research. The results show a social representation marked by a focused vision and assistance, pointing to the concentration of public resources in poor segments of the society and centered in the biomedical model of attention. It stands out that PSF did not reach their objectives to provide changes in the praxis in health. In relation to the social control, it is observed that only 5.9% of the interviewees know the CMS. The presented data show a great ignorance by the studied population on the sanitary system and conquered social laws, and many people still see SUS as a "health plan for the poor". Due to the lived reality, the need of the implementation of strategies is emphasized for the reach of larger powerment/liberation of the population, seeking to build effective possibilities so that their actors will be active participant of the process of construction of a common project, actually based on the democratic ideals of SUS, being PSF strategically important in the accomplishment of these actions.

O presente estudo analisa a representação social dos usuários sobre o SUS e o PSF, apresentando dados obtidos por intermédio de entrevistas semiestruturadas, utilizando o referencial teórico da pesquisa qualitativa. Os resultados mostram uma representação social marcada por uma visão focalizada e assistencialista, apontando para a concentração de recursos públicos em segmentos mais pobres da sociedade e centrada no modelo de atenção biomédico. Destaca-se que o PSF não conseguiu alcançar seus objetivos de proporcionar mudanças na práxis em saúde. Em relação ao controle social, observa-se que apenas 5,9% dos entrevistados conhecem o CMS. Os dados apresentados mostram um grande desconhecimento da população estudada sobre o sistema sanitário e os direitos sociais conquistados, sendo que para muitos o SUS ainda é visto como um "plano de saúde para os pobres". Diante da realidade vivenciada, ressalta-se a necessidade da implementação de estratégias para o alcance de maior empoderamento/libertação da população, visando construir possibilidades efetivas para que seus atores sejam participantes ativos do processo de construção de um projeto comum, realmente fundamentado nos ideais democráticos do SUS, sendo o PSF estrategicamente importante na realização dessas ações.

The present study analyzes the representation of the users of SUS and PSF, presenting data obtained by semi-structured interviews, using the theoretical referential of the qualitative research. The results show a social representation marked by a focused vision and assistance, pointing to the concentration of public resources in poor segments of the society and centered in the biomedical model of attention. It stands out that PSF did not reach their objectives to provide changes in the praxis in health. In relation to the social control, it is observed that only 5.9% of the interviewees know the CMS. The presented data show a great ignorance by the studied population on the sanitary system and conquered social laws, and many people still see SUS as a "health plan for the poor". Due to the lived reality, the need of the implementation of strategies is emphasized for the reach of larger powerment/liberation of the population, seeking to build effective possibilities so that their actors will be active participant of the process of construction of a common project, actually based on the democratic ideals of SUS, being PSF strategically important in the accomplishment of these actions.