RESUMO Objetivo: A alta prevalência e gravidade da toxoplasmose congênita no Brasil, com muitos indivíduos afetados desenvolvendo baixa visão, reforça a importância da avaliação da sua qualidade de vida. Este estudo tem como objetivo adaptar o Children's Visual Function Questionnaire (CVFQ) para a realidade sociocultural de crianças brasileiras e investigar suas propriedades psicométricas para avaliação da qualidade de vida relacionada à visão nesses indivíduos. Métodos: Estudo epidemiológico transversal aninhado de coorte de 142 crianças pré-escolares acompanhadas prospectivamente em hospital universitário de referência em Belo Horizonte, Brasil. Todas foram submetidos a exame oftalmológico completo, incluindo medida da acuidade visual e oftalmoscopia binocular indireta. Questionários foram aplicados aos pais e cuidadores, para avaliar a percepção da qualidade de vida, bem como o nível sócio-econômico das famílias. Análise estatística multivariada foi realizada para avaliar as propriedades psicométricas da escala de qualidade de vida. Resultados: Adaptações na versão brasileira do Children's Visual Function Questionnaire-7 originaram o Children's Visual Function Questionnaire-7-BR-toxo, um questionário para avaliar a percepção de pais/cuidadores sobre a qualidade de vida relacionada à visão de crianças pré-escolares com toxoplasmose congênita. Pela descrição, estrutura de variabilidade, e interpretação do agrupamento dos itens do questionário adaptado, identificaram-se seis subescalas: saúde geral, capacidade visual, desempenho visual/visão funcional, comportamento social e pessoal, impacto na família e tratamento. Crianças com baixa visão associada a toxoplasmose congênita tiveram escores mais baixos nas seguintes subescalas: acuidade visual (p=0,004), desempenho visual/visão funcional (p=0,008), impacto na família (p=0,001) e saúde geral (p=0,001). Conclusão: As propriedades psicométricas foram adequadas no tocante à validade do construto. O Children's Visual Function Questionnaire-7-BR-toxo foi capaz de registrar o impacto da deficiência visual nas famílias de crianças com toxoplasmose congênita.

ABSTRACT Purpose: The high prevalence and severity of congenital toxoplasmosis in Brazil, with several affected individuals progressing to low vision, emphasize the importance of evaluating their quality of life. In this study, the Children's Visual Function Questionnaire (CVFQ) was adapted to the sociocultural context of Brazilian children, and its psychometric properties were investigated for evaluating the vision-related quality of life of these individuals. Methods: This was a nested cross-sectional epidemiological study that prospectively monitored a cohort of 142 preschool children at a single referral university hospital in Belo Horizonte, Brazil. All children underwent complete ophthalmological examination, including visual acuity testing and binocular indirect ophthalmoscopy. Questionnaires were applied to their parents and caregivers to evaluate quality of life perception, as well as socioeconomic status of their families. Psychometric properties of the quality of life scale were evaluated by multivariate statistical analyses. Results: Adaptation to the Brazilian version of CVFQ-7 resulted in CVFQ-BR-toxo, a questionnaire for evaluating the perception of parents/caregivers about the vision-related quality of life of preschool children with congenital toxoplasmosis. The following six subscales were identified based on description, variability structure, and interpretation/grouping of items: general health, visual acuity, visual performance/functional vision, personal and social behavior, impact on family, and treatment. Children with low vision related to congenital toxoplasmosis had significantly lower scores for the following subscales: visual acuity (p=0.004), visual performance/functional vision (p=0.008), impact on family (p=0.001), and overall health (p=0.001). Conclusion: Psychometric properties were appropriate concerning the validity of the quality of life construct. CVFQ-BR-toxo could demonstrate the impact of vision impairment on families of children with congenital toxoplasmosis.

Resumo Objetivo A maioria dos programas de triagem pré-natal para toxoplasmose utiliza imunoensaios em amostras de soro de gestantes. Poucos estudos avaliam a acurácia dos testes de triagem em amostras de sangue seco, que são de fácil coleta, armazenamento e transporte. Este estudo teve como objetivo determinar o desempenho e avaliar a concordância entre um imunoensaio em sangue seco e um teste de referência em soro de gestantes de um programa de rastreamento pré-natal de base populacional para toxoplasmose no Brasil. Métodos Realizou-se um estudo transversal para comparar os imunoensaios Imunoscreen Toxoplasmose IgM e Imunoscreen Toxoplasmose IgG (Mbiolog Diagnósticos, Ltda., Contagem, Minas Gerais, Brazil) em sangue seco com o padrão de referência ensaio fluorescente ligado a enzimas (enzyme-linked fluorescent assay, ELFA, BioMérieux S.A., Lion, França) no soro de gestantes do Programa de Controle de Toxoplasmose Congênita de Minas Gerais. Resultados O exame em sangue seco foi capaz de discriminar os resultados positivos e negativos das gestantes quando comparado ao teste de referência, com acurácia de 98,2% para imunoglobulina G (IgG), e de 95,8% para imunoglobulina M (IgM). Conclusão O sangue seco apresenta bom desempenho e é uma amostra de fácil coleta, armazenamento e transporte, o que o torna um método promissor para programas de triagem pré-natal de toxoplasmose em países com dimensões continentais, recursos limitados, e alta prevalência de toxoplasmose, como é o caso do Brasil.

Abstract Objective Most prenatal screening programs for toxoplasmosis use immunoassays in serum samples of pregnant women. Few studies assess the accuracy of screening tests in dried blood spots, which are of easy collection, storage, and transportation. The goals of the present study are to determine the performance and evaluate the agreement between an immunoassay of dried blood spots and a reference test in the serum of pregnant women from a population-based prenatal screening program for toxoplasmosis in Brazil. Methods A cross-sectional study was performed to compare the immunoassays Imunoscreen Toxoplasmose IgM and Imunoscreen Toxoplasmose IgG (Mbiolog Diagnósticos, Ltda., Contagem, Minas Gerais, Brazil)in dried blood spots with the enzymelinked fluorescent assay (ELFA, BioMérieux S.A., Lyon, France) reference standard in the serum of pregnant women from Minas Gerais Congenital Toxoplasmosis Control Program. Results The dried blood spot test was able to discriminate positive and negative results of pregnant women when comparedwith the reference test, with an accuracy of 98.2% for immunoglobulin G (IgG), and of 95.8% for immunoglobulin M (IgM). Conclusion Dried blood samples are easy to collect, store, and transport, and they have a good performance,making this a promisingmethod for prenatal toxoplasmosis screening programs in countries with continental dimensions, limited resources, and a high prevalence of toxoplasmosis, as is the case of Brazil.

RESUMO: Biocidas e/ou antibióticos em concentrações sub-inibitórias podem promover o desenvolvimento de resistência adaptativa ou mesmo resistência cruzada nos micro-organismos. Entretanto, estudos destas respostas após o tratamento com a prata são escassos na literatura. Compostos a base de prata, incluindo as nanopartículas de prata (Ag-NPs), podem ser uma alternativa na prevenção e/ou tratamento de mastite bovina. Assim, este trabalho objetivou determinar o efeito de doses sub-inibitórias de Ag-NPs e dos íons Ag+ provenientes do nitrato de prata (AgNO3) sobre isolados de Staphylococcus aureus e de Escherichia coli, provenientes de leite de vacas com mastite. As Ag-NPs foram sintetizadas por redução química utilizando AgNO3 e citrato de sódio e a Concentração Mínima Inibitória (CMI) das Ag-NPs e íons Ag+ nos patógenos da mastite foi determinada. Os isolados foram expostos a concentrações sub-inibitórias de Ag-NPs ou de AgNO3 por 10 dias consecutivos para verificar o desenvolvimento de resistência adaptativa à prata pela mudança no valor da CMI, e de resistência cruzada com antibióticos pela mudança no perfil de sensibilidade em relação ao controle. AgNO3 apresentou-se mais efetivo contra todos os isolados. Não foi verificada alteração no valor da CMI nem do perfil de sensibilidade aos antibióticos, indicando que não houve seleção de resistência adaptativa à prata e de resistência cruzada aos antibióticos pelos micro-organismos estudados. O uso potencial da prata apresentado nos resultados é favorável à continuidade dos estudos objetivando a elaboração de terapias à base de prata para o tratamento da mastite bovina.

ABSTRACT: Biocides and/or antibiotics used in subinhibitory concentrations can promote the development of adaptive resistance or even cross-resistance in microorganisms. However, studies on these responses following silver treatments are scarce in the literature. Silver-based compounds, including silver nanoparticles (Ag-NPs), can be an alternative in the prevention and treatment of bovine mastitis. Thus, this research evaluated the effect of subinhibitory dosages of Ag-NPs and Ag+ ions from silver nitrate (AgNO3) on Staphylococcus aureus and Escherichia coli isolated from milk of cows with mastitis. Ag-NPs were synthesized by chemical reduction using AgNO3 and sodium citrate and the minimum inhibitory concentration (MIC) of Ag-NPs and Ag+ ions on the mastitis pathogens were determined. Isolates were exposed to subinhibitory concentrations of Ag-NPs or AgNO3 for 10 consecutive days to verify the development of adaptive resistance evaluated by changes in the MIC values. The development of cross-resistance with antibiotics was also studied, being verified by comparing the sensitivity profile of treated cells with non-treated cells. AgNO3 was more effective against all isolates. There was no change in the MIC values or in the antibiotic sensitivity profile for both bacteria following consecutive exposure to subinhibitory dosages of Ag-NPs or AgNO3, indicating that silver was not able to select adaptive resistance or cross resistance to the tested antibiotics. The potential of silver presented by these results is favorable to the continuity of studies aiming to elaborate silver-based therapies for the treatment of bovine mastitis.

ABSTRACT The objective of this study was to evaluate the quality of water purification system and identify the bacteria this system, predict bacterial adherence according to the hydrophobicity of these microorganisms and of the polypropylene distribution loop for purified water. The assessment of drinking water that supplies the purification system allowed good-quality physical, chemical, and microbiological specifications. The physicochemical specifications of the distributed purified water were approved, but the heterotrophic bacteria count was higher than allowed (>2 log CFU mL-1).The sanitation of the storage tank with chlorine decreased the number of bacteria adhered to the surface (4.34 cycles log). By sequencing of the 16SrDNA genes, six species of bacteria were identified. The contact angle was determined and polypropylene surface and all bacteria were considered to be hydrophilic, and adhesion was thermodynamically unfavorable. This case study showed the importance of monitoring the water quality in the purified water systems and the importance of sanitization with chemical agents. The count of heterotrophic bacteria on the polypropylene surface was consistent with the predicted thermodynamics results because the number of adhered cells reached approximate values of 5 log CFU cm-2.

The artisanal Minas cheese is produced from raw cow's milk and wooden utensils were employed in its manufacture, which were replaced by other materials at the request of local laws. This substitution caused changes in the traditional characteristics of cheese. Due to the absence of scientific studies indicating the microbial composition of biofilms formed on wooden forms, tables and shelves used in these cheese production, the present work evaluated the counts of Staphylococcus aureus, Escherichia coli, coliforms at 32 °C, yeasts, presumptive mesophilic Lactobacillus spp. and Lactococcus spp. in these biofilms, milk, whey endogenous culture and ripened cheese in two traditional regions: Serro and Serra da Canastra. Also, we checked for the presence of Salmonella sp. and Listeria monocytogenes in the ripened cheeses. The ultra structure of the biofilms was also assessed. Counts above legislation (> 2 log cfu/mL) for the pathogens evaluated were found in milk samples from both regions. Only one shelf and one form from Serro were above limits proposed (5 cfu/cm² for S. aureus and E. coli and 25 cfu/cm² for coliforms) in this study for contaminants evaluated. In Canastra, few utensils presented safe counting of pathogens. There was no Salmonella sp. and Listeria monocytogenes in the cheeses after ripening. Thus, the quality of the cheese is related to improving the microbiological quality of milk, implementation and maintenance of good manufacturing practices, correct cleaning of wooden utensils, and not its replacement.

INTRODUCTION: The aim of this study was to assess the epidemiological characteristics of Trypanosoma cruzi-infected mothers and the live birth conditions of neonates.METHODS:A serological survey with IgG-specific tests was conducted using dried blood samples from newborn infants in the State of Minas Gerais. T. cruzi infection was confirmed in mothers through positive serology in two different tests, and infected mothers were required to have their infants serologically tested after the age of 6 months. The birth conditions of the neonates were obtained from the System of Information on Live Births database.RESULTS:The study included 407 children born to T. cruzi-infected mothers and 407 children born to uninfected mothers. The average age of seropositive mothers was 32 years (CI95% 31.3-32.6), which was greater than the average age of seronegative mothers - 25 years (CI95% 24.8-25.2). The mothers' level of education was higher among uninfected mothers (41% had 8 or more years of education, versus 22% between the infected mothers). Vaginal delivery was more frequent among infected mothers. There was no evidence of inter-group differences with respect to the child's sex, gestational age, birth weight or Appearance, pulse, grimace, activity and respiration (APGAR) scores at 1 and 5 minutes.Conclusions:The level of education and the greater number of previous pregnancies and cases of vaginal delivery reflect the lower socioeconomical conditions of the infected mothers. In the absence of vertical transmission, neonates had similar health status irrespective of the infection status of their mothers.

The adhesion of the solids presents in food can difficult the process of surface cleaning and promotes the bacterial adhesion process and can trigger health problems. In our study, we used UHT whole milk, chocolate based milk and infant formula to evaluate the adhesion of Enterobacter sakazakii on stainless steel coupons, and we determine the work of adhesion by measuring the contact angle as well as measured the interfacial tension of the samples. Inaddition we evaluated the hydrophobicity of stainless steel after pre-conditioning with milk samples mentioned. E. sakazakii was able to adhere to stainless steel in large numbers in the presence of dairy products. The chocolate based milk obtained the lower contact angle with stainless steel surface, higher interfacial tension and consequently higher adhesion work. It was verified a tendency of decreasing the interfacial tension as a function of the increasing of protein content. The pre-conditioning of the stainless steel coupons with milk samples changed the hydrophobic characteristics of the surfaces and became them hydrophilic. Therefore, variations in the composition of the milk products affect parameters important that can influence the procedure of hygiene in surface used in food industry.

The aim of this work was to evaluate the utility of ELISA-based testing of total IgG (IgGt) antibodies and its subclasses (IgG1, IgG2, IgG3 and IgG4) against soluble (STAg) and recombinant (rSAG1 and rMIC3) antigens of Toxoplasma gondii for diagnosing congenital toxoplasmosis. Sera from 217 newborns initially testing positive for specific IgM in filter paper dried blood spots were tested for specific IgM and IgG by ELFA-VIDAS®. Congenital toxoplasmosis was confirmed in 175 and ruled out in 42 infants. The validity of the ELISA tests was determined using the persistence of IgG antibodies (ELFA-VIDAS® kit) at the end of 12 months, which is considered the reference test for the diagnosis of congenital toxoplasmosis. The frequency of positivity with IgGt against STAg, rSAG1 and rMIC3 was found in 97.2%, 96.3% and 80.2%, respectively, of the newborns with confirmed congenital toxoplasmosis. IgG1 reacted with all three antigens, while IgG3 and IgG4 reacted preferentially with rMIC3. Higher mean values of reactivity (sample optical density/cut-off) were found for all subclasses when using rMIC3. All of the antigens showed high sensitivity and low specificity in detecting anti-T. gondii IgGt and IgG1 and low sensitivity and high specificity in detecting IgG3 and IgG4. In conclusion, the combined detection of IgG antibody subclasses against recombinant toxoplasmic antigens may be useful for the early diagnosis of congenital toxoplasmosis.

The interaction between the surface of stainless steel and Bacillus cereus was studied in terms of the characteristics of interfacial interaction determined from the measurement of the contact angle of the surface of B. cereus and stainless steel in the presence or absence of B. cereus adherence. The microtopographies and the roughness of the surface of stainless steel and stainless steel adhered by B. cereus were evaluated with the help of atomic force microscopy and perfilometry. The strain of B. cereus studied was considered hydrophilic, whereas the stainless steel was considered hydrophobic. The adhesion was not thermodynamically favorable (ΔGadhesion > 0) between the stainless steel and the strain of B. cereus studied. Thus, the interaction between them was not favored by the thermodynamic aspect of adhesion. There was no difference (p > 0.05) in the roughness of the surfaces of stainless steel adhered by B. cereus when analyzed by atomic force microscope and perfilometry.

A eficiência dos procedimentos de limpeza e sanitização no controle de Staphylococcus aureus, Salmonella Enteritidis e Pseudomonasfluorescens aderidas em granito e aço inoxidável foi avaliada. Não houve diferença significativa (p > 0,05) na adesão destes microrganismos quando em cultura pura, em aço inoxidável. O número de células aderidas de P. fluorescens e S. Enteritidis foi maior (p < 0,05) que o número de células de S. aureus, em granito. Além disso, a adesão de P. fluorescens foi similar a de S. Enteritidis nesta última superfície. Em cultura mista com P.fluorescens, S. aureus aderiu menos (p < 0,05) em aço inoxidável (1,31 log UFC.cm-2) do que quando em cultura pura (6,10 log UFC.cm-2). Estes resultados sugerem que P. fluorescens inibiu a adesão de S. aureus. Entretanto, esta inibição não foi observada no processo de adesão em granito. Houve diferença significativa entre o número de células aderidas de S. aureus antes e após a pré-lavagem em ambas as superfícies e após o procedimento de limpeza para todos os microrganismos e todas as superfícies. A eficiência dos procedimentos de limpeza e sanitização não diferiram significativamente (p > 0,05) entre as superfícies. Entretanto, observou-se uma diferença (p < 0,05) entre as soluções sanitizantes utilizadas. Hipoclorito de sódio e ácido peracético apresentaram maior ação bactericida (p < 0,05) que o composto de amônia quaternária. Observou-se que S. aureus apresentou menor resistência à ação desses sanitizantes. Os resultados mostram a importância da adequada realização dos procedimentos de limpeza e sanitização para evitar a adesão bacteriana e formação de biofilme.

The effectiveness of cleaning and sanitizing procedures in controlling Staphylococcus aureus, Salmonella Enteritidis, and Pseudomonasfluorescens adhered to granite and stainless steel was evaluated. There was no significant difference (p > 0.05) in the adherence of pure cultures of these microorganisms to stainless steel. The numbers of P. fluorescens and S. Enteritidis adhered to granite were greater (p < 0.05) than the numbers of S. aureus. Additionally, the adherence of P. fluorescens was similar to the adherence of S. Enteritidis on granite surface. In a mixed culture with P. fluorescens, S aureus adhered less (p < 0.05) to stainless steel surfaces (1.31 log CFU.cm-2) than when in a pure culture (6.10 log CFU.cm-2). These results suggest that P. fluorescens inhibited the adherence of S. aureus. However, this inhibition was not observed in the adherence process for granite. There was a significant difference (p < 0.05) between the number of adhered cells before and after pre-washing for S. aureus on stainless steel and granite surfaces, and after washing with detergent for all microorganisms and surfaces. The efficiency of the cleaning plus sanitizing procedures was not significantly different (p > 0.05) between the surfaces. However, a significant difference was observed (p < 0.05) between the sanitizer solutions. Sodium hypochlorite and peracetic acid were more bactericidal (p < 0.05) than a quaternary ammonium compound. With regard to microorganisms, S. aureus was the least resistant to the sanitizers. These results show the importance of good cleaning and sanitization procedures to prevent bacterial adherence and biofilm formation.

The ability of bacteria to attach to surface and develop into a biofilm has been of considerable interest to food industry. Electrostatic, Lifhistz-van der Waals and Lewis acid-base forces are usually considered responsible for the interactions at the interface of the bacterial adhesion. The study of microbial adhesion thermodynamic is important because it represents the reflection of microbial surface and food processing surface physicochemical characteristics. This review examines the most important aspects involved in bacterial attachment to a surface with emphases in thermodynamics of adhesion process.

There is an increasing tendency to add natural antimicrobials of plant origin into food. The objective of this work was to develop a microbial sachet incorporated with allyl isothiocyanate (AIT), a volatile compound of plant origin, and to test its efficiency against growth of yeasts and molds, Staphylococcus sp. and psychrotrophic bacteria on sliced mozzarella cheese. Another objective was to quantify the concentration of AIT in the headspace of cheese packaging. A reduction of 3.6 log cycles was observed in yeasts and molds counts in the mozzarella packed with the antimicrobial sachet over 15-day storage time. The sachet also showed an antibacterial effect on Staphylococcus sp., reducing 2.4 log cycles after 12-day storage. Psychrotrophic bacteria species were the most resistant to the antimicrobial action. The highest concentration of AIT (0.08µg.mL-1) inside the active packaging system was observed at the 6-day of storage at 12 ºC ± 2 ºC. At the end of the storage time, AIT concentration decreased to only 10% of the initial concentration. Active packaging containing antimicrobial sachet has a potential use for sliced mozzarella, with molds and yeasts being the most sensitive to the antimicrobial effects.

A influência da velocidade de circulação do leite na adesão bacteriana de Pseudomonas aeruginosa foi avaliada em teste de uso simulado por meio de um modelo de circuito de processamento de leite. O circuito é composto por uma tubulação de aço inoxidável AISI 304, com 1,9 cm de diâmetro e 5,8 m de comprimento, além de um tanque de 25 L, utilizado como reservatório do produto e das soluções sanitizantes. O reservatório foi acoplado a uma bomba centrífuga de ½ HP, para impulsionar o alimento ou soluções de higienização pelo sistema equipado com cupons de prova em aço inoxidável nas formas cilíndrica, cotovelo 90º e T. As velocidades de circulação foram de 0,5, 1,0 e 1,5 m.s-1, correspondentes a fluxo turbulento com número de Reynolds de 14.000, 28.000 e 42.000, respectivamente. Quando se utilizou velocidade de 0,5 m.s-1, permaneceram aderidas à superfície 10,7% das células. Já nas velocidades e 1,0 e 1,5 m.s-1 as porcentagens de adesão foram de 5,36 e 4,9%, respectivamente, o que demonstra uma menor remoção de células aderidas à medida que o fluxo diminui, permitindo assim que mais células permaneçam aderidas na linha de produção, o que pode favorecer a formação de biofilmes.

The influence of the flow milk circulation in the bacterial adhesion of Pseudomonas aeruginosa was evaluated by simulation tests through a circuit model of milk processing. The circuit is composed of a tubulation of stainless steel AISI 304, with 1.9 cm of diameter, 5.8 m of length and a tank of 25 L used as the reservoir of the product and sanitizer solutions. The reservoir was coupled to a centrifugal bomb of ½ HP to impel the food or sanitizer solutions for the system equipped with 90º and T cylindrical stainless steel specimens. The speed of circulation values were 0.5, 1.0 and 1.5 m.s-1, corresponding to turbulent flow with number of Reynolds 14.000, 28.000 and 42.000, respectively. When flow of 0.5 m.s-1 was used 10.7% the cells remained adhered, however at the speed values of 1.0 and 1.5 m.s-1 the adhesion percentages were 5.36 and 4.9%, respectively. These findings indicate a lower removal rate of adhered cells as flow decreases allowing higher number of bacteria to adhere to the production line, which can favor the biofilm formation.

A adesão de Pseudomonas fluorescens foi avaliada em nove tipos de superfícies de processamento de alimentos por contagem padrão em placas. Superfícies de mármore, granito, aço inoxidável, poli(cloreto de vinila), poliuretano e silicone revestidos com tecido foram avaliadas. O número de células aderidas aumentou com o tempo de contato, alcançando 5,0-6,1 log UFC.cm-2 após 10 horas, o qual pode ser considerado um processo de adesão bem estabelecido. O número de células aderidas duplicou em 29,5 minutos em aço inoxidável e 23,5 minutos em poli(cloreto de vinila) revestido com tecido. Nas outras superfícies, em média, esse valor foi 9,8 minutos p > 0,05) no grau de adesão de células após 2 e 10 horas. As superfícies avaliadas com elevadas porcentagens de similaridade no nível de adesão e contagens de células aderidas foram poliuretano rugoso dupla face, silicone revestido com tecido e granito. As superfícies apresentaram características de microtopografias diferentes quando observadas por microscopia eletrônica de varredura. O experimento mostrou a importância da escolha adequada de materiais para contato com alimentos durante o processamento, os quais irão afetar os procedimentos de limpeza e sanitização.

The adherence of Pseudomonas fluorescens cells to nine food-processing contact surfaces was evaluated using the plate-count method. The surfaces include marble, granite, stainless steel, polyvinyl chloride, polyurethane, and silicone-coated cloth, which have been used only in a few studies concerning bacterial adherence. The number of cells adhered to the surfaces increased with contact time reaching 5.0-6.1 log CDM.cm-2 after 10 hours, which can be considered a well established adherence process. The number of adhered cells doubled in 29.5 minutes and 23.5 minutes on stainless steel and thin polyvinyl chloride-coated cloth, respectively. For the other surfaces, this value was 9.8 minutes on average. Marble, granite, thick polyvinyl-coated cloth, double-faced rugous polyurethane, and silicone-coated cloth were not different (p < 0.05) in their ability to adhere cells (CFU/cm²) after 2 and 10 hours. The surfaces that had higher percentage of similarity in the adhesion level and higher log CFU/cm² of adhered cells were double-faced rugous polyurethane, silicone-coated cloth, and granite. The surfaces showed very different microtopography characteristics when viewed using scanning electron microscopy. This experiment showed the importance of using appropriate materials for food contact during processing, which will affect the cleaning and sanitation procedures.

A adesão de substâncias orgânicas e de microrganismos em cupons de aço inoxidável ASI 304, #4 foi avaliada. A medida de Unidades Relativas de Luz (RLU) foi afetada em menor ou maior nível pelo tipo e concentração das substâncias orgânicas e suas combinações. Entretanto, se as amostras fossem oriundas de superfícies de processamento de alimentos, elas seriam consideradas em boas condições higiênicas pois as medidas de log URL ficaram abaixo de 2,18 log (< 150 URL) com ou sem adição das substâncias orgânicas e independente da concentração estudada, as células vegetativas apresentaram número de log URL para S. carnosus maior (p<0,05) do que para os esporos de B. subtilis. Amostras de superfícies aderidas com caseína, lipídio e sacarose e 2.9x10¹ CDM.cm-2 ou 2.9x10² CDM.ml-1 não apresentaram diferença significativa (p>0.05) na medida de ATP-bioluminescência. Entretanto, superfícies aderidas com 2.9x10³ CDM.cm-2 de esporos de B. subtilis e as substâncias orgânicas mostraram um aumento no log URL comparado com as superfícies contendo somente substâncias orgânicas.

Adhesion of organic substances and microorganisms on stainless steel surface was evaluated. The log RLU measurement was affected at a lower or higher degree, by type or concentration of the organic substances (casein, lipid, sucrose and their combinations) adhered to surface. However, if the samples analyzed were from the food processing surfaces, they would have been considered to be under satisfactory hygienic conditions with log RLU < 2.18 (< 150 RLU). The log RLU measurements of Staphylococcus carnosus-adhered surfaces, combined with or without the organic substances, were higher (p<0.05) than those of the Bacillus subtilis spores-adhered surface, regardless of the concentration. The samples taken from the surfaces adhered with the casein, lipid, sucrose and 2.9x10¹ DMC.cm-2 and 2.9x10² DMC.ml-1 did not have any significant differences (p>0.05) on ATP-bioluminescence measurements. However, the surfaces adhered with 2.9x10³ DMC.cm-2 of B. subtilis spores and organic substances showed an increase in the log RLU measurement compared to surfaces containing only the organic substances.