• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 44
  • 14
  • 8
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 73
  • 73
  • 35
  • 14
  • 13
  • 12
  • 12
  • 12
  • 12
  • 11
  • 10
  • 10
  • 10
  • 9
  • 9
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Tratamentos de aquecimento, inativação térmica e virulência do Trypanosoma cruzi (Chagas, 1909) de vetores e reservatório em polpa in natura de açaí (Euterpe oleraceae Martius) na doença de Chagas aguda de transmissão alimentar no Estado do Pará, Brasil / Heat treatment, thermal inactivation and virulence of Trypanosoma cruzi (Chagas, 1909) from vectors and reservoir in in natura açai pulp (Euterpe oleraceae Martius) about foodborne acute Chagas' disease at Pará State, Brazil

Labello Barbosa, Rodrigo, 1983- 26 August 2018 (has links)
Orientadores: Luiz Augusto Corrêa Passos, Ana Maria Aparecida Guaraldo / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-26T12:27:38Z (GMT). No. of bitstreams: 1 LabelloBarbosa_Rodrigo_D.pdf: 3872986 bytes, checksum: eed1c71b567c33f273e37132ebefabcc (MD5) Previous issue date: 2014 / Resumo: Na amazônia brasileira, microepidemias de doença de Chagas aguda (DCA) humana são notificadas por meio de caracterização clínica e epidemiológica após associação ao consumo de polpa in natura de açaí contaminada com Trypanosoma cruzi. Dada a sua relevância econômica, cultural e considerando que a refrigeração e o congelamento não são métodos eficientes à prevenção da DCA de transmissão alimentar, os objetivos desse estudo foram determinar um binômio "temperatura x tempo" mínimo necessário à inativação ou morte do T. cruzi em polpa de açaí e avaliar a possibilidade experimental da transmissão dessa parasitose, proveniente de vetores e reservatório de diferentes localizações do Estado do Pará, por contaminação acidental no alimento. Na primeira etapa, 105 tripomastigotas da cepa Y de T. cruzi foram misturadas à polpa in natura de açaí e submetidas a tratamentos térmicos entre 37ºC e 49ºC em um banho ultratermostático de alta precisão, por até uma hora, sob homogeneização constante. Na segunda etapa, 105 tripomastigotas de T. cruzi (TcI) de diferentes fontes e localizações do Pará, comparando-se à cepa Y de T. cruzi (TcII), foram misturadas, à temperatura ambiente, à polpa in natura de açaí. Em ambas etapas, quando necessário, as misturas contaminadas foram submetidas à tamisação forçada. O inóculo (controle negativo, controle positivo ou grupo teste), de até 200?L, foi administrado via intraperitoneal, gavagem ou oral em hospedeiros isogênicos imunodeficientes C.B-17-Prkdcscid/Pas Unib ou B6.129S7Rag1-/-tmMom/J Unib, sob antibioticoterapia prévia (1,75mg/dia). A parasitemia foi realizada de acordo com o método de Brener e a mortalidade foi registrada. T. cruzi preservou sua virulência em polpa de açaí à 43±0,1ºC durante 20 minutos, causou DCA e morte em até 24 dias após as infecções experimentais, via intraperitoneal. T. cruzi de R. pictipes da Mata do Val-De-Cans, de Belém, apresentou DCA, com início de parasitemia e morte, respectivamente, nos dias 32,0±3,0 e 40,0±3,0. T. cruzi de R. pictipes do Rio Ajuaí, de Abaetetuba, apresentou DCA, com início de parasitemia e morte, respectivamente, nos dias 35,0±1,0 e 49,0±1,0. T. cruzi de P. opossum da Ilha do Combu, de Belém, apresentou DCA, com início de parasitemia e morte, respectivamente, nos dias 45,0±2,0 e 51,0±1,0, via oral. Não houve diferença significativa para a DCA de vetores de diferentes localizações, contudo, houve diferença significativa para a DCA entre T. cruzi de vetores e reservatório, bem como em relação à cepa Y de T. cruzi (teste de Duncan, 99% de confiança). Portanto, a cocção da polpa in natura de açaí acima de 44ºC poderá prevenir a DCA de transmissão alimentar. T. cruzi obtidos de diferentes fontes e localizações do Pará, após o contato com a polpa in natura de açaí, à temperatura ambiente, foram capazes de preservar sua virulência in vivo, causar DCA e morte em até 52 dias após as infecções experimentais. Uma educação básica de qualidade facilitará que boas práticas de higiene ocorram durante toda a cadeia produtiva do açaí e evitará a ocorrência de DCA de transmissão alimentar na região Norte do país nas próximas décadas / Abstract: In the Brazilian Amazon, outbreaks of acute Chagas¿ disease (ACD) in humans are reported by clinical and epidemiological characterization after association with the ingestion of in natura fruit¿s açai of pulp contaminated with T. cruzi. Due the economic and cultural relevance and considering that the cooling and freezing are not efficient to prevent the ACD foodborne, the aims of this study were determine a minimum binomial "temperature x time" and necessary to inactivation or death of T. cruzi in fruit¿s açai of pulp and evaluate the possibility of experimental transmission of this parasitosis, from vectors and reservoir at different locations at Pará State, in an accidental contamination in food. In the first stage, 105 trypomastigotes of T. cruzi Y strain were mixed with in natura fruit¿s açai of pulp and heat-treated between 37ºC and 49ºC in a high-precision water bath, by up to an hour, under constant homogenization. In the second stage, 105 trypomastigotes of T. cruzi (TcI) from different sources and locations at Pará, comparing with T. cruzi Y strain (TcII), were mixed with in natura fruit¿s açai of pulp, at room temperature. In both stages, when necessary, contaminated mixtures were subjected to forced sieving process. The inoculum (negative control, positive control or test group), up to 200 ?L, was administered intraperitoneal, gavage or oral in inbred immunodeficient hosts CB-17-Prkdcscid/Pas Unib or B6.129S7Rag1-/-tmMom/J Unib, under previous antibiotic therapy (1,75 mg/day). Parasitemia was scored as recommended by Brener and mortality registered. T. cruzi retained its virulence in fruit¿s açai of pulp at 43±0,1ºC for 20 minutes, caused ACD and death in mice up to 24 days after experimental infections, intraperitoneally. T. cruzi from Rhodnius pictipes, Val-de-Cans¿ forest, Belém, presented ACD and death, respectively, on days 32,0±3,0 and 40,0±3,0. T. cruzi from R. pictipes, Ajuaí River, Abaetetuba, presented ACD and death, respectively, on days 35,0±1,0 and 49,0±1,0. T. cruzi from Philander opossum, Combu¿s Island, Belém, presented ACD and death, respectively, on days 45,0±2,0 and 51,0±1,0, orally. There was not significant difference for the ACD from vectors of different locations, however, there was significant difference for the ACD between T. cruzi from vectors and reservoir, as well as for the T. cruzi Y strain (Duncan test, ? 0,01). Therefore, cooking in natura fruit¿s açai of pulp above 44ºC can prevent ACD foodborne. T. cruzi from different sources and locations at Pará, after contact with in natura fruit¿s açai of pulp, at room temperature, can retain its virulence in vivo, cause ACD and death in up to 52 days after experimental infections. A quality basic education will facilitate good hygiene practices occur throughout the productive chain of açai and will prevent ACD foodborne in the northern region of Brazil in next decades / Doutorado / Parasitologia / Doutor em Parasitologia
52

The influence of thermal and nonthermal food preservation methodologies on the liberation and ultrastructure of bacterial endotoxins

Olivier, Dedré January 2010 (has links)
Thesis (D. Tech. (Biomed. Tech.)) -- Central University of Technology free State, 2010 / Consumer demands for fresh, microbiologically safe foods with high organoleptical and nutritional quality has led to the development of novel food preservation technologies as alternatives or enhancements to traditional preservation techniques. An example of these novel preservation technologies is high hydrostatic pressure (HHP) processing. It involves the applications of static pressure of 50 to 1 000 mega Pascals (MPa) to solid or packaged liquid foods, with varying holding times. The combination of factors to enhance preservation is increasingly being used in industry, e.g. the use of different temperatures and additives (hurdles) can enhance the preservative effect of HHP. In this study the influence of HHP on organism viability and growth response was assessed. The organisms evaluated included Escherichia coli O111, Listeria monocytogenes (UAFSBCC) and Staphylococcus aureus (ATCC 25923), in peptone water, which was subjected to HHP of 200 MPa for 15 minutes at 8 and 50 ºC respectively. Subsequent to the mentioned pressurisation, sub-culturing was performed and growth responses were evaluated at 0, 6, 18, 24, 30, 42 and 48 hours. Bacterial survival and growth response was measured by means of intact cell count, colony forming units and optical density. From the results it was eminent that bacterial cells were only sublethally injured and were able to repair within 48 hours of enriched sub-culturing. E. coli O111 proved to be most sensitive to HHP with Staphylococcus aureus (ATCC 25923) most resistant. This study also proved that bacterial concentration and inactivation rate are inversely proportionate to each other. Subsequent to growth and cell repair assessments, E. coli O111 was selected as a model to evaluate the effect of sublethal HHP on the liberation and toxicity of bacterial endotoxins (free and cell wall bound). It is also known that different extraction procedures extract different lipopolysaccharides (LPS) fractions and therefore LPS was extracted from the test broth by a combination method of Folch, Lees & Sloane-Stanley, and Venter and Ivanov. The extraction yielded a biphasic system, LPS with reduced lipid content in the upper phase (aqueous) and LPS with increased lipid content in the lower phase (organic). Following extraction the Limulus amebocyte lysate (LAL) test was performed to quantify the concentration (assumed) of LPS in the aqueous and organic phases. Free LPS was detected within six hours in the supernatant in the high and low bacterial loads, moreover the toxicity response of post HHP cell damage was more pronounced at 50 ºC (hurdle) than that observed for the treatments at 8 ºC (hurdle) and more so in the organic phases. The latter implied that HHP not only resulted in quantity LPS variation but also in structural change. However membrane repair was apparently complete after 48 hours, as differences in toxicity were no longer evident. Furthermore, the use of a porcine IL-6 ELISA assay was evaluated as an alternative for the customary LAL as a biomarker for pyrogenic substances in matrixes. Porcine whole blood was challenged for IL-6 production by LPS in the samples from the organic and aqueous systems. A porcine IL-6 enzyme-linked immunosorbent assay was used to assess IL-6 expression in whole blood after being challenged with LPS. From the results it emanated that HHP caused in a change in LPS structure which resulted in a decreased IL-6 expression in whole blood, indicating that structural adaptation of the cell membrane in response to HHP influenced the ability of LPS to stimulate macrophages and monocytes. Therefore, further research and development would be required to evaluate the influence of post HHP LPS on human IL-6 expression. When comparing the porcine IL-6 with the LAL no correlation in toxicity could be established in any of the treatment parameters. Finally it can be concluded that HHP had an influence in the structural morphology of LPS. These structural changes could result in LPS being more toxic, it could also have an effect on the accuracy of immunological assessments, the ability to form biofilm, and susceptibility to phages.
53

Isolation and antimicrobial susceptibility characterisation of listeria SPP. in selected food premises in Central South Africa

Snyman, Marina J. January 2011 (has links)
Thesis (M. Tech. Environmental health) -- Central University of technology, Free State, 2011 / Microbial pathogens play an important role in the food industry where they could cause disease and subsequently significant economic losses. Limited information is available on the situation with regard to Listeria in food products in South Africa. However, much research is being done in the rest of the world on Listeria indicating serious problems as a result of resistance development against various antimicrobial agents, including the organic acids. It is hypothesised that the situation with regard to resistance development may be more serious than generally admitted. Isolation of 200 different food samples was done by using a slightly modified EN ISO 11290-1/A1:2004 standard method. Identification of presumptive positive colonies was confirmed as Listeria by API (Analytical profile index) Listeria. API positive cultures were subjected to 16S rDNA sequencing to compare and confirm identification. Isolates and standard strains were screened for resistance to food preservatives such as organic acids and antibiotics used in the current treatment regime for Listeria infections. The organisms evaluated included isolated strains namely Listeria monocytogenes, Listeria welshimeri, Listeria innocua and their corresponding ATCC (American type culture colletion) strains. An agar dilution method as described by the Clinical and Laboratory Standard Institute (CLSI) was used to determine the minimum inhibitory concentrations (MICs) of 11 antibiotics and 13 organic acids and salts for all the isolates. Overall antibiotic susceptibility patterns of all the isolates indicated high level susceptibility to all the antibiotics tested. Susceptibility to all the organic acids was notably reduced at pH 7 in all the isolates and control strains. Eight highly susceptible strains were selected for induction and represented each of the species isolated. These isolates were exposed to increasing concentrations of three antibiotics and three organic acids. MICs were again determined for all the induced strains for five antibiotics and three organic acids. Proteins extracted from the induced strains were separated on discontinuous SDS-PAGE slab gels to generate total protein profiles. Notable variations were observed in MICs, although induction with antibiotics as well as organic acids did not result in general resistance development. However, evidence was provided that continuous exposure to antimicrobial agents may cause Listeria spp. to develop resistance to different antimicrobial agents. Further research and in depth studies on mechanisms involved in the development of resistance to food preservatives would, therefore, be required. Finally, it is concluded that Listeria monocytogenes may be a possible threat in the Central South African food industry, which deserves more attention. The situation may actually pose a problem that is overseen, because only a small percentage of people that get sick from food, would seek medical advice.
54

Influence of extrinsic stresses on growth and endotoxin profiles of escherichia coli and pseudomonas aeruginosa

Smith, Elvina Melinda January 2011 (has links)
Thesis (M. Tech. Environmental health) -- Central University of technology, Free State, 2011 / The threat to the world food supply and the concern for public health as a result of food-borne diseases has been established as a constant global problem. The safety of food, in particular, is of significance to consumers and producers alike. Regarding the diseases related to food-borne pathogens, the disease syndromes affecting the entire human body has become inestimable. The focus of the study was to establish the effect of sanitisers, detergents and household storage temperatures on the growth profiles and toxicity of typical food related organisms. The endotoxin, LPS of these Gram-negative organisms in communal growth as compared to pure culture was the focus of the investigation. Pure and communal samples were grown in the presence of the extrinsic stresses including storage temperature. The change in toxicity was measured using the Limulus amoebocyte lysate test and the possible change in the immune response was determined using the porcine-IL-6 test. The first obvious finding was that the overall sensitivity of organisms was similar for the same sanitiser and the same detergent. The sensitivity of the community varied slightly but in principle followed the same pattern as the individual organisms. The LD50 for all growth samples were as follows: 32 X 104 PPM for sanitiser 1 and sanitiser 2, and 16X 104 PPM for detergent 1 and detergent 2. Growth in community was found not to be the arithmetic sum of the individual growth patterns. The detergents had a marked effect on the growth of all samples throughout the growth cycle. The sub-optimum household storage temperatures inhibited the growth throughout the cycle but growth did not cease entirely. This finding may have revealed that the acceptable refrigeration temperatures still allows for pathogen growth and thus for biofilm formation. Furthermore, the response of the community to the extrinsic stresses appears to be entirely different to the pure culture and therefore needs further exploration to address the problem. Regarding the quantification by LAL, it was found that the enumeration of the food-borne pathogens isolated from households might not be indicative of acclimatisation obtained over short periods of time and the causal stress turning these organisms into more or less toxic pathogens. The sanitisers and detergents induced competition in colonial fashion and the growth varied between feast and famine. The extrinsic stresses had a more observable effect on the older biofilm as this was shown by a decrease in toxicity. The toxicity as quantified by porcine-IL-6 yielded a mixture of stimulation levels for the cytokine. The toxicity change indicated by the test showed a variation between lowering and noticeable elevation for pure cultures. A marked elevation in toxicity was detected in community at storage temperature 4°C. The study would suggest that porcine IL-6 is not an accurate biomarker for pyrogenicity since its sensitivity is questionable and its inability to indicate toxicity if there is a possible change in the LPS structure. It should be said that further elucidation is needed to support this finding. Having said all that, it is no surprise that the validation for the two tests favours the LAL procedure. The large room for pre-test stimulation in pigs’ blood also tends to cast a shadow on the IL-6 findings. The findings of the study contribute to the body of knowledge covering the effects and quantitative analysis of toxins in food. This should add to safety assurance by sensitizing the industry regarding the most suitable analytical methodologies to apply.
55

Incidence of Listeria monocytogenes in milk from producers in the Maseru area

Moshoeshoe, Senate Louisa January 1900 (has links)
Thesis (M. Tech. (Biomedical Technology)) -- Central University of technology, Free State, 2013 / The objective of this study was to determine the prevalence of Listeria monocytogenes and also to assess the general hygiene of fresh milk in the Maseru area, Lesotho. A total of 200 milk samples (40 pasteurised and 160 raw milk samples) were used for the research. Raw milk samples were collected from the local farmers at the Dairy reception as they bring it for selling. Pasteurised milk samples were bought from different milk selling points in the Maseru area. The total aerobic plate count, total coliform count and total E. coli count for 160 raw milk samples and 40 pasteurised samples were performed to determine the quality of milk. Milk was enriched in selective broths to increase detection sensitivity and was directly plated on selective agars for direct bacterial enumeration. About 54.4% of the of the raw milk samples had total aerobic plate counts greater that 200 000 cfu/ml while 55.6% (89/160) of the raw samples had high counts of greater than 20 cfu/ml for total coliforms, and 21.9% (35/160) of the samples had higher than expected total E. coli counts. High total coliform count was detected in 17.5% (7/40) of the pasteurised milk samples and about 67.5% (27/40) of these samples exceeded the limit for total aerobic plate counts. The counts exceeded the milk standards for pasteurised milk. Phosphatase activity was detected in seven pasteurised milk samples, whereas 33 tested negative for phosphatase activity. Some pasteurised milk samples tested positive for coliform counts which exceeded the maximum limits according to national standards for pasteurised milk. However, most of the pasteurised samples (82.5%) had acceptable counts of less than 20 cfu/ml. API and PCR were used for confirmation and amplification of the isolated Listeria strains. The prevalence of Listeria was found to be (3.75%). Listeria species were found in 6 out of 200 samples tested (160 raw milk samples and 40 pasteurised milk), and were only detected in the raw milk samples. Five species belonged to Listeria monocytogenes and one was Listeria innocua. None of the Listeria was detected in the pasteurised milk samples. Serotyping was done through multiplex PCR with D1, D2, FlaA and GLT primers to determine the serovar groups of L. monocytogenes. All six isolates revealed 214 bp gene which identifies the serotypes in Lineages I or III. The genetic fingerprinting of the isolated Listeria was also determined. Enterobacterial Repetitive Intergenic Consensus (ERIC) sequence-based PCR was used to generate DNA fingerprints with ERIC specific primers. On the basis of ERIC-PCR fingerprints, three different DNA patterns could be discriminated among the analysed isolates. Three L. monocytogenes isolates showed similar DNA banding patterns, while two isolates both had different profiles. A questionnaire was used to determine consumption of raw (unpasteurised) milk or pasteurised milk and its products and it was completed by 300 households from the community. Although there was no indicated prevalence of raw (unpasteurised) milk consumption from the community, participants indicated symptoms alleged to consumption of pasteurised milk and/or milk products. According to community perception some of the dairy products consumed were allegedly implicated in food poisoning illnesses experienced. Participants indicated more symptoms with both fresh and sour milk consumption than in cheese and yogurt consumption.
56

Estudo da relação estrutural e atividade antimicrobiana da Leucocina C-TA33a de Leuconostoc mesenteroides TA33a /

Santos, Leonardo Alves dos January 2019 (has links)
Orientador: Saulo Santesso Garrido / Resumo: Os peptídeos antimicrobianos (PAMs) são uma alternativa interessante como bioconservantes de alimentos devido a sua eficiência e, principalmente, à baixa toxicidade quando comparados aos conservantes químicos tradicionais. As bacteriocinas, uma classe de PAMs, têm atividade antimicrobiana em espécies responsáveis pela degradação de alimentos e, portanto, atualmente são exploradas como bioconservadores. A Leucocina C-TA33a (LeuC), um tipo de bacteriocina produzida pela cepa bacteriana Leuconostoc mesenteroides TA33a, é conhecida por ter um amplo espectro antimicrobiano. Estudos de alinhamento da estrutura primária de diferentes bacteriocinas revelaram que LeuC conserva em sua estrutura regiões homólogas também compartilhadas por outras bacteriocinas, como Sacacina P, Bavaricina A e Enterocina A, possivelmente revelando uma importante relação entre essas sequências de aminoácidos e suas atividades antimicrobianas. Este estudo tem como objetivo sintetizar diferentes peptídeos baseados na estrutura primária da Leucocina CTA33a, a fim de identificar as principais regiões responsáveis pela atividade antimicrobiana. Os peptídeos LeuC-Nt, LeuC-0Cys, LeuC-Ala9, LeuC-Ala14 e LeuC-Cys9,14 foram sintetizados por metodologia de fase sólida, purificados e analisados por HPLC e caracterizados por ESI-MS. Ensaios em meio líquido foram realizados para a determinação do percentual de inibição de crescimento microbianos dos peptídeos sobre espécies patogênicas. Os micro-organismos testados fora... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Antimicrobial peptides (PAMs) are an interesting alternative, because biopreservatives present high efficiency and low toxicity when compared to classic preservatives. Bacteriocins, a class of PAMs, have antimicrobial activity in species responsible for food degradation and are currently being exploited as biopreservatives. The Leucocin C-TA33a (LeuC), a type of bacteriocin, is produced by the Leuconostoc mesenteroides TA33a strain and is known for a broad antimicrobial spectrum. Studies of alignment of the primary structure of different bacteriocins revealed that LeuC retains in its structure homologous regions also shared by other bacteriocins, such as Sacacin P, Bavaricin A and Enterocin A, possibly revealing an important relationship between these amino acid sequences and their antimicrobial activities. This study aims to synthesize different peptides based on the primary structure of Leucocin C-TA33a, with the objective of identifying the main regions responsible for antimicrobial activity. The peptides LeuC-Nt, LeuC-0Cys, LeuC-Ala9, LeuC-Ala14 and LeuC-Cys9,14 were synthesized by solid phase methodology, purified by HPLC and characterized by ESI-MS. Liquid assays were performed to determine the percentage of inhibition of microorganisms of the peptides on pathogenic species. The microorganisms tested were Salmonella serotype Typhimurium, Staphylococcus aureus, Escherichia coli and Listeria monocytogenes. Studies were also conducted through circular dichroism, molecular ... (Complete abstract click electronic access below) / Mestre
57

Avaliação de indicadores e identificação de estratégias de sucesso de segurança dos alimentos adotadas após à fusão de duas grandes empresas de serviço de alimentação

Magalhães, Cris Rocha Pinto January 2017 (has links)
Na atualidade é cada vez mais comum o consumo de refeições fora de casa. No Brasil, além da opção dos restaurantes comerciais, em escolas, universidades e mesmo em hospitais, é muito comum a presença de serviços de alimentação dentro das empresas onde os funcionários realizam as refeições, durante o seu turno de trabalho. Em paralelo, a incidência de surtos de Doenças Transmitidas por Alimentos (DTA) ainda é uma realidade no Brasil e no mundo. Esses fatos têm intensificado a necessidade de implementação dos sistemas de gestão da segurança dos alimentos (SGSA) e seus controles no ramo de serviços de alimentação. Em meio a esse contexto, o presente estudo avaliou as estratégias de gestão da segurança dos alimentos adotadas após a fusão de duas grandes empresas do ramo de restaurantes industriais no Brasil, cada uma com mais de 30 anos desde a fundação, cuja união deu origem a uma empresa de aproximadamente 39 mil colaboradores e uma receita combinada de R$ 2 bilhões, servindo em média 1,8 milhões de refeições diariamente. Para isso, nesse estudo foram analisados crítica e estatisticamente os indicadores de gestão de segurança dos alimentos (taxa de ocorrências alimentares, auditorias internas e capacitações) dos 1 440 restaurantes distribuídos no Brasil, considerando um total de 4 488 dados ao longo de seis anos (2010 a 2015), contemplando o período anterior e posterior à fusão, e implantação do novo sistema de gestão. A análise qualitativa das práticas de gestão de segurança dos alimentos adotadas foi realizada através da Análise SWOT (strengths, weaknesses, opportunities, threats), que possibilitou identificar a base da escolha da nova estratégia de gestão de segurança dos alimentos adotada após a fusão. A análise estatística dos indicadores possibilitou identificar as oportunidades de melhoria, assim como as estratégias de sucesso na implantação do SGSA. Os resultados demonstraram uma correlação linear entre a conformidade dos itens críticos (IC) e técnica operacional (TO) da auditoria interna, com o menor número de ocorrências alimentares em unidades que apresentaram 100% de conformidade em IC. Ainda, restaurantes com um histórico de auditorias internas apresentaram melhores resultados, principalmente quando foram avaliados a cada quatro meses. Também foi observado que as unidades com líderes treinados apresentaram melhores resultados em auditoria interna para IC proporcionalmente à sua maior frequência de participação. Além disso, essas unidades também reportaram mais suspeitas de ocorrências alimentares do que as unidades cujos líderes não haviam recebido treinamento. Da mesma forma, as unidades com equipes operacionais treinadas no mínimo anualmente apresentaram melhores resultados de auditoria interna do que as não treinadas, sendo identificado que a frequência quadrimestral de treinamentos resultou nos melhores resultados de TO e IC. Esses resultados foram avaliados e discutidos, utilizando outros trabalhos de referência bibliográfica no tema, permitindo assim, a elaboração de uma proposta de modelo de SGSA para Serviços de Alimentação. / Currently, eating out is becoming increasingly usual. In Brazil, in addition to the option of commercial restaurants, schools, universities and even hospitals, it is very common the presence of food services within companies where employees eat meals during their work shift. On the other hand, the incidence of outbreaks of Foodborne Diseases (FD) is still a reality in Brazil and in the world. These facts have intensified the need to implement food safety management systems (FSMS) and their controls in the food services sector. Considering this context, the present study evaluated the food safety management strategies adopted after the merger of two large industrial restaurant companies in Brazil, each with more than 30 years since their foundation, whose union gave rise to a company of approximately 39 thousand employees and a combined revenue of R$ 2 billion, serving on average 1.8 million meals daily. Therefore, in this study, the indicators of food safety management (food event rate, internal audits and training) of the 1 440 restaurants distributed in Brazil were analyzed critically and statistically, considering a total data of 4 488 over six years (2010 to 2015), before and after the merger, and implementation of a new management system. The qualitative analysis of food safety management practices was carried out through the SWOT (strengths, weaknesses, opportunities, threats) analysis, which enabled to identify the basis for choosing the new food safety management strategy adopted after the merger. Statistical analysis of the indicators allowed the identification of opportunities for improvement, as well as successful strategies in the implementation of the FSMS. The results showed a linear correlation between the compliance of critical items (CI) and operational technique (OT) of the internal audit, with the lowest number of food occurrences in units that presented 100% compliance with CI. Moreover, restaurants with a history of internal audits performed better, especially when they were evaluated every four months. It was also observed that the units with trained leaders presented better results in internal audit for CI in proportion to their higher frequency of participation. In addition, these units also reported more suspicion of food occurrences than units whose leaders had not received training. Likewise, the units with operational teams trained at least annually presented better internal audit results than the non-trained ones, and the quarterly frequency of training resulted in the best results of OT and CI. These results were evaluated and discussed, through other academic articles in the theme, allowing the elaboration of a proposal of the FSMS model for Food Services.
58

Boas práticas de manipulação de alimentos em cozinhas domiciliares: práticas de trabalhadores domésticos / Food safety practices in household kitchens: practices of domestic workers

Oliveira, Allys Vilela de 07 July 2013 (has links)
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2014-10-09T13:17:45Z No. of bitstreams: 2 Dissertação - Allys Vilela de Oliveira - 2013.pdf: 7595804 bytes, checksum: 80235a511700ad25a0223ccfef5a63bf (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2014-10-09T13:21:53Z (GMT) No. of bitstreams: 2 Dissertação - Allys Vilela de Oliveira - 2013.pdf: 7595804 bytes, checksum: 80235a511700ad25a0223ccfef5a63bf (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-10-09T13:22:22Z (GMT). No. of bitstreams: 2 Dissertação - Allys Vilela de Oliveira - 2013.pdf: 7595804 bytes, checksum: 80235a511700ad25a0223ccfef5a63bf (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2013-07-07 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The Foodborne Diseases stand out as a public health problem, and the residences are among the main sites of occurrence. In many residences the household employee holds the position of food handler, being directly responsible for the health of the food served at the table. The aim of this study was to analyze the practices of food handling and responses to a questionnaire on these practices by domestic workers in their professional environment. Therefore, it was observed hygiene techniques applied for 35 domestic workers during the preparation of a meal, and then were asked about their habits when handling food at work. The instruments used to collect data were a checklist of practice of food safety and a questionnaire about the topic. We calculated descriptive indicators of the sample mean, median and standard deviation. The association between the questionnaire responses and attitudes during observation were calculated by Kappa coefficient and chi-square test (α = .05). The mean observation time of the preparation of the meal in each residence was 46 minutes, while the questionnaire required an average of 15 minutes for each subject answers it. The observation of food handling these individuals showed that 64% of their attitudes were adequate, while in their responses to the questionnaire reported having the habit of performing 70% of procedures. It was found that personal hygiene was the area with lower fitness (40%), while the responses to the questionnaire indicated environmental hygiene as with larger mismatches (56%). The cleaning of hands was prominent among the inadequate procedures during the observation, approximately 85% of the sample committed the fault. Another point that stands out is the use of dish cloth, a practice common in kitchens for 80% of subjects. There was a positive association between education and care practices as observed with the expiration date of food products and defrost foods properly. Already the questionnaire responses were associated with schooling in five items concerning appropriate attire in meal preparation, cleaning and proper storage of food. Statistical analyzes showed that hygiene practices applied in the preparation of the meals were not associated with the answers provided. We conclude that the handling of food for domestic workers exposes diners to contamination by Foodborne Diseases, and that there is a difference between the application of food safety practices in food preparation and answers regarding their practices. / As Doenças Transmitidas por Alimentos se destacam como problema de saúde pública, e as residências estão entre os principais locais de ocorrência. Em muitos domicílios o empregado doméstico ocupa o cargo de manipulador de alimentos, sendo o responsável direto pela sanidade dos alimentos servidos à mesa. O objetivo deste trabalho foi analisar as práticas de manipulação de alimentos e as respostas a um questionário sobre estas práticas por trabalhadores domésticos em seu ambiente profissional. Para tanto, observou-se as técnicas de higiene aplicadas por 35 empregados domésticos durante o preparo de uma refeição, em seguida foram questionados quanto a seus hábitos ao manipular alimentos no trabalho. Os instrumentos utilizados na coleta de dados foram uma lista de verificação de Boas Práticas de Manipulação de Alimentos e um questionário sobre hábitos de higiene ao manipular alimentos. Foram calculados os indicadores descritivos da amostra: média, mediana e desvio padrão. A associação entre respostas ao questionário e atitudes durante a observação foram calculadas por coeficiente Kappa e teste qui-quadrado de Pearson (α=0,05). O tempo médio de observação do preparo da refeição em cada residência foi de 46 minutos, enquanto a aplicação do questionário exigiu em média 15 minutos para cada sujeito responde-lo. A observação da manipulação de alimentos destes indivíduos demonstrou que 64% das suas atitudes foram adequadas, enquanto em suas respostas ao questionário informaram ter o hábito de realizar 70% dos procedimentos adequados. Foi possível constatar que a higiene pessoal foi a área com menor adequação (40%), enquanto as respostas ao questionário indicaram a higiene ambiental como a com maiores inadequações (56%). A higienização de mãos foi destaque entre os procedimentos inadequados durante a observação, aproximadamente 85% da amostra cometeu a falha. Outro ponto que chama atenção é o uso de pano de prato, prática comum nas cozinhas para 80% dos sujeitos. Verificou-se uma associação positiva entre escolaridade e as práticas observadas quanto ao cuidado com a data de validade de produtos alimentícios e ao descongelamento adequado dos alimentos. Já as respostas ao questionário estiveram associadas com a escolaridade em cinco itens relativos a vestimentas adequadas no preparo de refeições, armazenamento e higienização adequados dos alimentos. As análises estatísticas comprovaram que as práticas de higiene aplicadas no preparo das refeições não estavam associadas às respostas fornecidas. Conclui-se que a manipulação dos alimentos por empregados domésticos expõe os comensais à contaminação por Doenças Transmitidas por Alimentos, e que há uma divergência entre a aplicação dos procedimentos de higiene no preparo de alimentos e as respostas quanto as suas práticas.
59

Survival of Listeria monocytogenes, Salmonella spp., and Staphylococcus aureus in raw yellowfin tuna during refrigerated and frozen storage

Mou, Jing 06 March 2013 (has links)
The consumption of seafood in the United States has increased rapidly in recent years due to high quality protein and health benefits of seafood. Seafood can be a carrier for bacteria normally distributed in the marine environment and, in some cases, can be contaminated by human pathogens. Therefore, there is a potential health risk if seafood is consumed raw or undercooked. However, information regarding prevalence of foodborne pathogens in retail seafood products and the ability of pathogens to survive in the products during refrigerated and frozen storage is limited. The objective of this study was to generate such information for a better understanding of distribution of foodborne pathogens in seafood products and provide data which might be used for risk assessment of foodborne infection associated with seafood consumption. A total of 45 seafood products were collected from local retail stores and analyzed for aerobic plate counts (APC) and psychrotrophic bacterial counts (PBC) as well as presence of foodborne pathogens, including Escherichia coli O157:H7, Salmonella, Listeria monocytogenes, Staphylococcus aureus, Vibrio parahaemolyticus, and Vibrio vulnificus according to procedures described in the U.S. Food and Drug and Administration Bacteriological Analytical Manual (BAM). Presumptive isolates for each foodborne pathogen were further characterized by biochemical reactions using commercial identification kits and confirmed with polymerase chain reaction (PCR) assay. The samples had bacterial populations ranging from 1.90 to 6.11 CFU/g for APC and from 2.00 to 6.78 CFU/g for PBC. According to the microbiological criteria of International Commission on Microbiological Specifications for Foods (ICMSF), all 45 samples were considered acceptable quality (APC < 10⁷ CFU/g, E. coli < 3 MPN/g) with most samples (93.3%) being good quality (APC < 5 × 10⁵ CFU/g, E. coli < 3 MPN/g). No E. coli O157:H7, Salmonella, S. aureus, V. parahaemolyticus, and V. vulnificus was detected in any samples. Two previously frozen shrimp products (4.4%) were confirmed to carry L. monocytogenes. Studies of growth and survival of L. monocytogenes (3 strains), S. aureus (2 strains), and Salmonella (2 serovars) in raw yellowfin tuna meat stored at 5 - 7 °C for 14 days revealed that L. monocytogenes had the ability to multiply in the tuna meat during refrigerated storage while populations of S. aureus and Salmonella were reduced by 1 to 2 log CFU/g after 14 days at 5 - 7 °C. Studies of holding raw yellowfin tuna meat contaminated with L. monocytogenes, S. aureus, and Salmonella at -18 ± 2 °C for 12 weeks observed that all three pathogens, except Salmonella Newport, in tuna samples survived the frozen storage with less than 2- log of reductions in the populations over 12 weeks of storage. No viable cell of Salmonella Newport was detected in samples after 42 days storage at -18 °C. Raw seafood can be a carrier of foodborne pathogens, particularly L. monocytogenes, and many foodborne pathogens can survive in frozen products for several months. Consumption of raw or undercooked seafood products may lead to human infection if the products are contaminated with pathogens. Therefore, sanitation standard operating procedure (SSOP), good manufacturing practice (GMP) and hazards analysis and critical control points (HACCPs) programs shall all be implemented in the seafood industry to prevent seafood products from being contaminated with foodborne pathogens during handling and processing. Moreover, proper storage of raw seafood products and avoiding cross-contamination during handling at the retail levels also helps to minimize risk of human infection associated with ready-to-eat products. / Graduation date: 2013
60

Bacteriological and epidemiological studies of campylobacter spp. in Swedish broilers /

Hansson, Ingrid, January 2007 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2007. / Härtill 6 uppsatser.

Page generated in 0.0697 seconds