Abstract Ingesting food contaminated by pathogens and/or their toxins can cause foodborne illness. In this sense, this study investigated the occurrence of enterotoxigenic S. aureus in frozen cheese bread dough and assessed the production and thermosensitivity of SEA in artificially contaminated cheese dough. E. coli counts were determined by MPN. Confirmation of the presence of S. aureus was carried out by biochemical and molecular identification. The detection of the genes sea, seb, sec, and sed was performed using the PCR. The detection of SEA in artificially contaminated cheese dough, before and after baking at 180 ºC for 35 minutes was performed using the RPLA. All samples contaminated with E. coli had NMP < 5.0×102 CFU / g. None of the isolated S. aureus strains expressed the classical enterotoxin genes sea, seb, sec, and sed. However, as there are 23 serologically distinct staphylococcal enterotoxins, we cannot rule out the possibility that strains expressed other enterotoxin-encoding genes. Laboratory tests showed the presence of SEA in cheese bread dough artificially contaminated with SEA-producing S. aureus after 8 h of incubation at 10 or 20 °C. Heat treatment at 180 °C for 35 minutes was not sufficient to inactivate SEA in artificially contaminated cheese bread previously incubated for 24 h at 10 or 20 °C. These results indicate a potential health risk to consumers of cheese bread and underscore the need for ingredient quality control and measures to prevent the multiplication of S. aureus during product manufacture and storage.

Cátions e ânions majoritários são espécies químicas de grande importância nos diversos compartimentos aquáticos, porém, pouco abordados de forma exclusiva na bacia amazônica. Neste sentido, o objetivo deste estudo foi avaliar a dinâmica espacial de Na+, Ca2+, K+, Mg2+, Cl- e SO4 2- em um trecho do rio Solimões-Amazonas, levando-se em consideração a alcalinidade, potencial hidrogeniônico (pH), condutividade elétrica (CE), sólidos totais em suspensão (STS) e carbono orgânico total (COT). As coletas foram realizadas em maio, julho e setembro de 2012 em sete pontos na calha principal do rio Solimões-Amazonas e na foz de alguns dos principais tributários: rios Jutaí, Juruá, Japurá e Purus. Os cátions e ânions foram analisados por cromatografia de íons, STS por gravimetria, pH por potenciometria, alcalinidade por titulação potenciométrica, CE por condutimetria e o COT por oxidação catalítica por combustão. As concentrações médias dos cátions seguiram esta ordem Ca2+>Na+>Mg2+>K+ e dos ânions SO4 2->Cl-. De montante à jusante a tendência foi diminuição nas concentrações de cátions e ânions, das variáveis pH, CE, STS e alcalinidade, além do aumento das concentrações de COT. O presente estudo evidenciou mudanças nas características químicas sofridas pelo rio Solimões em seu curso. O aporte dos tributários pode ser apontado como um dos fatores responsáveis por essas modificações.

Major cations and anions are chemical species with great importance in different water compartments. However, no specific attention has been given to them in the Amazon basin. This study aimed to assess the spatial dynamic of Na+, Ca2+, K+, Mg2+, Cl- and SO4 2- in a specific section of the Solimões-Amazonas river taking into account the alkalinity, hydrogen potential (pH), conductivity electric (EC), total suspended solids (TSS) and total organic carbon (TOC). Samples were collected in May, July and September 2012 in seven points in the Solimões-Amazonas River and in the mouth of some of its main tributaries: rivers Jutaí, Juruá, Japurá and Purus. Cations and anions were analyzed by ion chromatography, TSS by gravimetry, pH by potentiometry, alkalinity by potentiometric titration, EC by conductimetry and TOC by catalytic oxidation combustion. The average cation concentrations followed this order: Ca2+ > Na+ > Mg2+ > K+ and anion SO4 2- > Cl. From the upstream of the river towards its downstream section there was a tendency for a decrease in cations and anions accumulation, pH, EC, TSS and alkalinity. On the other hand, there was an increase in TOC. The present study showed changes in chemical characteristics of Solimões River along its course. It was observed the contribution of the tributary rivers as one of the responsible factors for these changes.

A multiplicacão de Staphylococcus aureus e a produção de enterotoxinas estafilocócicas dependem de fatores intrínsecos e da temperatura de armazenamento dos alimentos. O objetivo deste trabalho foi discutir o padrão estafilococos coagulase positiva (ECP) para massas alimentícias, estabelecido pela RDC n.º 12 de 2001 da ANVISA, baseando-se nos resultados de atividade de água (a w), potencial hidrogeniônico (pH) e contagem de ECP. Cinquenta amostras de 25 tipos de massas de treze marcas diferentes foram analisadas. A contagem de ECP de todas as amostras foi menor que 10 Unidades Formadoras de Colônia por grama (UFC/g), inferior a 5,0 × 10³ UFC/g, estabelecido como limite máximo pela legislação. As médias de a w das massas secas com e sem recheio variaram entre 0,70 e 0,61, respectivamente, o que impossibilita a multiplicação de ECP e produção de toxina. Por outro lado, a média de a w das massas frescas foi de 0,96, o que propicia o desenvolvimento desse padrão microbiológico. Os resultados obtidos neste trabalho indicam que a a w poderia ser utilizada como parâmetro para determinar em quais tipos de massas o padrão ECP deveria ser pesquisado, ou seja, para massas alimentícias cruas que possibilitassem a multiplicação de Staphylococcus spp. (a w > 0,86).

The growth of Staphylococcus aureus and the production of staphylococcal enterotoxins depend on intrinsic food factors and the food storage temperature. The aim of this study was to discuss the coagulase-positive staphylococcal count limit (CPS) for pasta, established by RDC no 12, 2001, ANVISA, based on the results of water activity (a w), hydrogenionic potential (pH) and the CPS count. Fifty samples of 25 types of pasta from 13 different brands were analyzed. The CPS count of all the samples analyzed was less than 10 Colony-Forming Units per gram (CFU/g), below the limit of 5.0 × 10³ CFU/g, established by Brazilian Legislation. The average a w for dry pasta with and without stuffing varied between 0.70 and 0.61, which prevents the development of CPS and toxin production. On the other hand, the average a w for fresh pasta was 0.96, which allows for the growth of CPS. The results of this study indicate that a w may be used as a parameter to determine in which kind of pasta the CPS count should be done, ie for pasta that allow for the development of Staphylococcus spp. (a w > 0.86).

The aim of this study was to verify the efficiency of the BAX® system for the detection of Salmonella spp. in raw chicken meat. The conventional culture method (IN 62, MAP) was used as a reference method. A total of 8,813 chicken carcass samples were analyzed. In the first part of the study, 1,200 samples were analyzed using the BAX® System and the conventional culture method. In the second part, 7,613 samples were analyzed by the BAX® system, and the conventional method was used only for samples that tested positive for Salmonella spp. by the BAX® system. The sensitivity, specificity, relative accuracy, positive predictive value, and negative predictive value obtained in the first part of this study were 100%, 92.3%, 96.4%, 53.3% and 100%, respectively. The BAX® system showed no false-negative results and reduced the time to obtain presumptive positive results. It is a suitable method for use in laboratories that perform a large number of food samples analyses daily. However, the conventional method is still required to confirm the presence of Salmonella spp. in samples that test positive using the BAX® system.

Mutations into codons Aspartate-87 (62%) and Serine-83 (38%) in QRDR of gyrA were identified in 105 Salmonella strains resistant to nalidixic acid (94 epidemic and 11 of poultry origin). The results show a high incidence of mutations associated to quinolone resistance but suggest association with others mechanisms of resistance.

Campylobacter jejuni is the most common thermophilic Campylobacter associated with human enteritis in many countries. Broilers and their by-products are the main sources for human enteritis. Refrigeration and freezing are used to control bacterial growth in foods. The effect of these interventions on survival of Campylobacter jejuni is yet not quite understood. This study evaluated the effect of storage temperature on the survival of C. jejuni in chicken meat stored for seven days at 4ºC and for 28 days at -20ºC. The influence of selective enrichment on recovery of Campylobacter was also evaluated. Thirty fresh chicken meat samples were analyzed and 93.3% was contaminated with termotolerant Campylobacter spp. with average count of 3.08 Log10 CFU/g on direct plating. After refrigeration, 53.3% of the analyzed samples tested positive for Campylobacter and the average count was 1.19 Log10 CFU/g. After storage at -20ºC, 36.6% of the samples were positive with a verage count of 0.75 Log10 CFU/g. C. jejuni was detected after enrichment, respectively, in 50% of the fresh, 36.7% of the refrigerated and 33.3% of the frozen meat samples analyzed. No difference was detected for the recovery of C. jejuni from fresh, refrigerated or frozen samples after selective enrichment, showing that this microorganism can survive under the tested storage conditions.

ELISA competitivo indireto (ic-ELISA) baseado em anticorpos monoclonais foi desenvolvido para a detecção de ocratoxina A (OTA) em café verde, torrado e instantâneo. Os reagentes imunológicos necessários à reação consistiram de OTA-BSA (4,76 mg/mL), anti-OTA.7 MAb (diluído 2x10³) e anti IgG-HRP (diluído 10³), apresentando limite de detecção de 3,73 ng OTA/g. Os coeficientes de correlação (r) entre o imunoensaio e cromatografia líquida de alta eficiência (CLAE) foram de 0,98 (café verde), 0,98 (torrado) e 0,86 (instantâneo). Ic-ELISA detectou valores superestimados de OTA em relação a CLAE, com valor ELISA/CLAE variando de 0,66 - 1,46 (café verde), 0,96 - 1,11 (torrado) e 0,93 - 1,82 (instantâneo). As recuperações médias de OTA adicionada em café (5 - 70 ng/g) foram de 81,53 % (café verde), 46,73 % (torrado) e 64,35 % (instantâneo) por ELISA, em relação a 80,54 %, 45,91 % e 55,15 % por CLAE, respectivamente. A interferência de matriz no imunoensaio foi minimizada pela diluição das amostras previamente à análise por ELISA. O ic-ELISA desenvolvido pode ser considerado uma técnica alternativa simples, sensível e específica para análise de OTA, contribuindo para a qualidade e segurança de produtos de café.

An indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) for ochratoxin A (OTA) detection in green, roasted and instant coffees was developed using anti-OTA monoclonal antibody. Immunological reagents prepared were OTA-BSA (4.76 mg/mL), anti-OTA.7 MAb (2x10³-fold dilution) and HRP-anti IgG (10³-fold dilution). The detection limit was 3.73 ng OTA/g and correlation coefficients (r) between this immunoassay and high performance liquid chromatography were 0.98 for green coffee, 0.98 for roasted and 0.86 for instant. OTA levels detected by ic-ELISA were higher than by HPLC, with ELISA/HPLC ratio of 0.66 - 1.46 (green coffee), 0.96 - 1.11 (roasted) and 0.93 - 1.82 (instant). ELISA recoveries for OTA added to coffee (5 - 70 ng/g) were 81.53 % for green coffee, 46.73 % for roasted and 64.35 % for instant, while recoveries by HPLC were 80.54 %, 45.91 % and 55.15 %, respectively. Matrices interferences were minimized by samples dilution before carrying out the ELISA assay. The results indicate that MAb-based ic-ELISA could be a simple, sensitive and specific screening tool for OTA detection, contributing to quality and safety of coffee products.

Salmonelose é a infecção bacteriana de origem alimentar mais freqüente no Paraná, Brasil, e os surtos estão associados, principalmente, ao consumo de ovos, carne de aves e derivados. Os objetivos deste trabalho foram identificar os sorovares de Salmonella isolados de carcaças de frango e caracterizá-los molecularmente por REP e ERIC-PCR, assim como identificar os fagotipos de Salmonella Enteriditis. Dos 25 isolados de Salmonella spp. analisados, 18 foram identificados como Enteriditis, 4 como Braenderup, 2 como Worthington e 1 como infantis. Dos 18 isolados de Enteriditis, 14 foram PT4, 2 PT4a, 1 PT7 e 1 RDNC, por se tratar de colônia rugosa. REP-PCR forneceu padrão eletroforético distinto de 10 a 13 bandas distribuídas entre 120 e 2072 pb para cada sorovar diferente testado. A ERIC-PCR mostrou um padrão de 4 a 5 bandas entre 180 e 1000 pb e foi menos discriminativa quando comparada à REP-PCR. Os resultados encontrados confirmaram que a fagotipagem é uma ferramenta útil e discriminativa para o sorovar Enteriditis. Apesar do pequeno número de sorovares testados, os resultados sugerem que a REP-PCR parece ser um método atrativo a ser utilizado no futuro para a discriminação preliminar de sorovares de Salmonella.

Salmonellosis is the most prevalent bacterial food-borne disease in the State of Paraná, Brazil, and the outbreaks are often associated with consumption of poultry products. The aim of this study was to serotype Salmonella strains isolated from chicken carcasses and characterize them molecularly using REP and ERIC-PCR. The phage types of Salmonella Enteriditis were also identified. Of the 25 Salmonella strains analysed, 18 were identified as Enteriditis, 4 as Braenderup, 2 as Worthington and 1 as infantis. Of the 18 Enteriditis isolates, 14 were PT4, 2 PT4a, 1 PT7 and 1 "reacted, but did not conform" - RDNC. Distinct REP-PCR profiles with 10 to 13 fragments distributed between 120 and 2072 pb were easily obtained for each serovar tested. ERIC-PCR showed patterns of 4 to 5 fragments between 180 and 1000 pb and less discriminatory power than REP-PCR. The results confirmed that phage typing is a useful tool to differentiate into sorovar Enteriditis. Although it is recognized that only a limited number of strains was tested in this study, the results suggest that REP-PCR could be an attractive choice to be used in the future as a preliminary method of Salmonella sorovar discrimination.

O método convencional de detecção de Salmonella spp., além de trabalhoso, consome longo tempo, necessitando-se normalmente de 4 a 5 dias para a confirmação da presença dessa bactéria no alimento. Portanto, o emprego de métodos rápidos e simples é importante para o diagnóstico laboratorial de toxinfecção alimentar e para o controle de qualidade. O objetivo principal deste trabalho foi a padronização de ensaio imunoenzimático-ELISA para detecção de Salmonella Enteritidis em alimentos. O ensaio utilizou anticorpos policlonais para flagelina produzidos em coelho. O anti-soro apresentou pouca reação cruzada com os sorotipos de Salmonella e as diferentes espécies de enterobactérias testadas. A sensibilidade do ensaio foi de 10(4) células/mL, quando testado em cultivo puro. O conjugado peroxidase manteve-se estável durante dois meses a 4ºC e o seu uso deve ser exclusivamente durante este tempo. O ensaio padronizado apresentou simplicidade e rapidez, com sensibilidade de 1 célula/25g de maionese de batata e cenoura, após enriquecimento em água peptonada tamponada durante 24 horas a 37°C, sem necessidade de enriquecimento seletivo.

Traditional cultural methods for the detection of Salmonella in foods is a labour-intensive and time-consuming, taking 4 to 5 days for the final results to be known. Therefore, simplified and rapid methods are required for both diagnosis of foodborne diseases and microbiological food quality control. The aim of this study was to develop an enzyme-linked immunosorbent assay (ELISA) for the detection of Salmonella Enteritidis in foods. The assay used a polyclonal detector antibody to flagelin raised in rabbit. The anti-sera obtained showed slight cross-reactions to others Salmonella serotypes and Enterobacteriaceae species tested. The method sensitivity was of 10(4) cells/mL of pure culture. The horseradish peroxidase conjugate was stable up to two months at 4ºC and for this reason it should be used only during this period. The method also showed sensitivity of 1 cell per 25g of potato and carrot salad containing home-made mayonnaise by using only a cultural stage in buffered peptone water incubated for 24 hours at 37°C. In conclusion, the method showed to be practical and reliable to detect Salmonella Enteritidis in foods.

Trata-se de um estudo etnográfico desenvolvido no contexto do Projeto Cansanção - PROCAN - realizado no período de 1987 a 1990. Analisa-se um conjunto de informações sobre os padrões culturais que cercam o ato alimentar dos grupos sociais que habitam Cansanção, região do semi-árido baiano. Foram investigados modelos de alimentação, a partir de depoimentos das mulheres trabalhadoras rurais, observando-se as estratégias de sobrevivência alimentar, enquanto ações concretas com vistas a assegurar a reprodução da unidade familiar. O medo da proximidade da doença e da morte são referências fundamentais como modos de conceber a vida e de definições de hábitos alimentares, apoiadas pela compreensão particular de seus próprios mundos. Os hábitos que cercam o ato alimentar em Cansanção indicam uma relação entre a sobrevivência do corpo e a reprodução da unidade familiar, permeados pelo cotidiano da seca. A atividade central, o trabalho da roça, subordinado às condições precárias de vida permite a produção e reprodução de formas de conceber a vida, e em particular, define os vários conceitos e classificações sobre as necessidades de alimentar o corpo. Em algumas áreas do município de Cansanção, observa-se um modo de conceber o alimento a partir de uma razão subordinada a valores do comércio, mas o fenômeno da seca constitui ainda o determinante da cultura alimentar da população e de suas ações concretas para solucionar a carência alimentar no grupo familiar.

This study was developed within the context of the project Cansanção - PROCAN- developed by the Federal University of Bahia, Brazil. The study analyzed information concerning cultural patterns which surround the eating habits of the social groups which live in the semi-arid region of Bahia. It is an ethnographic study carried out over the period of 1987 to 1990. The subject of the investigation was the cultural aspect of eating habits of female rural workers, observing the strategies of eating survival as concrete actions to ensure the reproduction of the family unit. The fear of imminent illness and death proves to be fundamental references as ways of conceiving life and of defining food habits, supported by their own understanding of their worlds. The food habits in Cansanção reveal a relationship between the body survival and the reproduction of the family unit, permeated by the daily life in a drought-stricken region. The main activity, the work in the fields, subordinated to precarious living conditions, allows the production and reproduction of ways of interpreting life and, in particular, defines various concepts and classifications about the need to provide sustenance to the body. In some areas of Cansanção food is considered linked to its commercial value; however, the phenomenon of drought still remains the determining factor in the food culture of the population and in its concrete actions to solve the lack of food within the family group.

O objetivo principal deste trabalho foi propor um esquema de imunização para a produção de anticorpos para a enterotoxina estafilocócica A (EEA). O método de referência preconizado por Robbins e Bergdoll foi modificado visando a redução do número de doses e da quantidade de toxina administrada por animal. O melhor esquema de imunização empregou doses de 5, 6, 20, 50, 100 e 200<FONT FACE="Symbol">m</font>g de EEA administradas a intervalos de 0, 8, 24, 59, 62 e 67 dias, respectivamente. Esse esquema empregou um total de 381 <FONT FACE="Symbol">m</font>g, equivalente à redução de 107 <FONT FACE="Symbol">m</font>g de EEA, em relação ao método de referência. O título médio do anti-soro utilizando a técnica de Optimum Sensitivity Plate - OSP foi de 1:60 e de ELISA 1:100.000. A ausência de reações cruzadas com outras enterotoxinas estafilocócicas, observada nas técnicas de OSP e ELISA, indicou alta especificidade do anticorpo para EEA, com a vantagem da redução da quantidade de toxina purificada necessária para a imunização.

An immunization scheme for production of antiserum to staphylococcal enterotoxin A (SEA) is proposed. The reference method of Robbins and Bergdoll was modified to reduce the number of doses and the amount of toxin used per animal. The best immunization scheme used injections in days 0, 8, 24, 59, 62 and 67. The amount of toxin at each injection was 5, 6, 20, 50, 100 and 200<FONT FACE="Symbol">m</font>g, respectively. The total amount of toxin was 381<FONT FACE="Symbol">m</font>g, which corresponded to a reduction of 107<FONT FACE="Symbol">m</font>g in the amount of toxin for each animal when compared to the reference method. The average antiserum titer using the Optimum Sensitivity Plate - OSP was 1:60 and using ELISA the titer was 1:100.000. The lack of cross-reactivity with other staphylococcal enterotoxins indicated high specificity of the antibody to SEA. The proposed immunization scheme was adequate to produce specific SEA antisera, with high titers and the aditional advantage of reducing the amount of purified SEA required for immunization.