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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
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Avaliação de indicadores e identificação de estratégias de sucesso de segurança dos alimentos adotadas após à fusão de duas grandes empresas de serviço de alimentaçãoMagalhães, 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.
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Influência da forma infectante do Toxoplasma gondii na doença aguda humana: revisão sistemática de surtos epidêmicos / Influence of infective form of Toxoplasma gondii in human acute illness: systematic review of outbreaksEkman, Claudio Cesar Jaguaribe 21 November 2012 (has links)
A toxoplasmose é uma zoonose de distribuição mundial, altamente prevalente na população humana e animal. A doença é geralmente benigna e autolimitada, mas pode ocasionar déficits visuais graves em cerca de 2 a 3% dos indivíduos acometidos, e ainda, assumir formas graves e letais em pacientes imunossuprimidos e em fetos de gestantes com infecção aguda. As principais formas de transmissão da doença são o consumo de água e alimentos crus contaminados com oocistos e a ingestão de carne crua ou mal cozida contendo cistos teciduais do Toxoplasma gondii. Na literatura há relatos de vários surtos epidêmicos de toxoplasmose humana, porém a análise descritiva destes surtos é pontual e restrita, com informações isoladas em relação período de incubação e gravidade dos sintomas que poderiam estar relacionados à forma infectante do agente. No presente trabalho analisamos a influência da forma infectante do T. gondii no quadro da doença aguda humana, através de revisão sistemática das principais bases de dados bibliográficos na área de Saúde Pública (Cochrane, Embase, Food Sciences & Tech Abstracts, Lilacs, PubMed, Scopus e Web of Science), além de publicações em boletins epidemiológicos (Boletim Epidemiológico Paulista, Boletim Eletrônico Epidemiológico SVS) e anais de congressos nacionais e internacionais de áreas correlatas. As pesquisas nas bases de dados bibliográficos foram realizadas utilizando idiomas em português e inglês para os termos: surtos de toxoplasmose humana (human toxoplasmosis outbreak). Os critérios de inclusão dos estudos levaram em consideração artigos e resumos que relatassem surtos epidêmicos de toxoplasmose humana com descrição da forma infectante do agente e quadro clínico da doença. Na busca eletrônica inicial, foram obtidos 431 artigos referentes a surtos mundiais e nacionais de toxoplasmose humana, provenientes de diferentes formas de transmissão da doença, porém foram elegíveis para o trabalho somente 33 artigos, incluindo um surto ocorrido recentemente na região de Araraquara, Estado de São Paulo, cuja investigação epidemiológica foi conduzida por nossa equipe. A análise da revisão sistemática sugere que o número de casos confirmados nos surtos é maior quando a transmissão ocorre por oocistos, sendo o solo e a água associados a esta forma de transmissão. Quanto aos achados clínicos, a infecção por cistos parece induzir um período de incubação menor do que o observado para oocistos. Não houve relação da forma infectante com o sexo predominante e faixa etária nas populações amostrais. Os surtos foram descritos mais frequentemente nas Américas que em outros continentes. Estes dados sugerem que a forma infectante do T.gondii interfere no quadro da toxoplasmose aguda. / Toxoplasmosis is a zoonosis of worldwide distribution, highly prevalent in the human and animal population. The disease is usually benign and self-limiting but can cause severe visual deficits in about 2 to 3% of affected individuals, and also take serious and lethal in immunosuppressed patients and in fetuses of pregnant women with acute infection. The most important modes of transmission are consumption of water and uncooked food contaminated with oocysts and the ingestion of raw or undercooked meat containing tissue cysts of Toxoplasma gondii. In literature there are reports of several human toxoplasmosis outbreaks, but the descriptive analysis of these outbreaks is punctual and restricted, with isolated information regarding the incubation period and severity of symptoms that could be related to the infective form of the agent. In this study we analyze the influence of infective form of T. gondii in the context of acute human disease, through a systematic review of the major bibliographic databases in the area of Public Health (Cochrane, Embase, Food Sciences & Tech Abstracts, Lilacs, PubMed, Scopus e Web of Science), as well as publications in epidemiological bulletins (Boletim Epidemiológico Paulista, Boletim Eletrônico Epidemiológico SVS) and annals of national and international conferences in related areas. This research on bibliographic databases was performed using English and Portuguese languages for the terms: human toxoplasmosis outbreak (surtos de toxoplasmose humana). The inclusion criteria of the studies took into consideration articles and abstracts that reported outbreaks of human toxoplasmosis with description of the infective form of the agent and the clinical disease. In the initial electronic search, 431 articles were obtained regarding global and national outbreaks of human toxoplasmosis from different main forms of disease transmission, but were eligible to work only 33 articles, including a recent outbreak in the region of Araraquara State of São Paulo, which epidemiological investigation was conducted by our team. The analysis of systematic review suggests that the number of confirmed cases in outbreaks is greater when the transmission occurs by oocysts, and the soil and water are associated with this form of transmission. Regarding clinical findings, cysts infection seems to induce an incubation period less than that observed for oocysts. No relationship between the infective form with the predominant sex and age group in the sample populations. Outbreaks were reported more frequently in the Americas than in other continents. These data suggest that the infective form of T. gondii interferes in the context of acute toxoplasmosis.
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Boas práticas de manipulação de alimentos em cozinhas domiciliares: práticas de trabalhadores domésticos / Food safety practices in household kitchens: practices of domestic workersOliveira, Allys Vilela de 07 July 2013 (has links)
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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.
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Perfil de susceptibilidade antimicrobiana e genes de virulência em cepas de Salmonella spp. isoladas de alimentos associados ou não à toxinfecções alimentares / Antimicrobial resistance profile and virulence genes in Salmonella spp. strains isolated from foods associated and non-associated to foodborne disease outbreaksRuth Estela Gravato Rowlands 12 June 2008 (has links)
Salmonella é o agente etiológico mais comumente envolvido em casos e surtos de doenças diarréicas de origem alimentar no Brasil e outros países. A preocupação com este patógeno é, ainda, maior quando se verifica o surgimento e disseminação de cepas multi-resistentes e potencialmente mais patogênicas. O presente estudo teve como objetivo caracterizar 237 cepas Salmonella spp. distribuídas entre 50 sorovares diferentes, isoladas de alimentos associados e não associados à toxinfecções alimentares, quanto ao perfil de susceptibilidade antimicrobiana e presença dos genes de virulência spvC, invA, sefA e pefA. O gene invA foi detectado em todas as cepas de Salmonella. Com relação aos demais genes estudados, spvC e pefA foram encontrados em 48,1% e 44,3% das cepas, respectivamente. O gene sefA foi detectado em 31,6% das cepas, estando presente somente entre as cepas de S. Enteritidis. Ainda com relação à presença dos genes de virulência, as cepas de S. Enteritidis foram classificadas em três perfis, com predominância (90,7%) do perfil constituído pelos quatro genes de virulência. Quanto ao perfil de susceptibilidade antimicrobiana, 46,8% do total de cepas avaliadas foram sensíveis a todos os agentes antimicrobianos, 51,9% resistentes à pelo menos uma droga e 1,3% das cepas apresentaram apenas resistência intermediária. Multi-resistência foi observada em 10,5% das cepas. As maiores taxas de resistência foram observadas para estreptomicina (35,9%), ácido nalídixico (16,9%), tetraciclina (5,9%) e gentamicina (4,6%). Não foram detectadas cepas resistentes à cefoxitina, cefalotina, cefotaxima, amicacina, ciprofloxaxina e imipenem. Os resultados do presente estudo mostram a ampla distribuição dos genes de virulência e ocorrência de resistência antimicrobiana tanto nas cepas associadas a surtos como naquelas não envolvidas em toxinfecções alimentares, sendo os produtos de origem avícola fontes importantes de Salmonella com estas características. / Salmonella is the most common causative agent of cases and outbreaks of foodborne diarrhoeal diseases in Brazil and other countries. The concern with this pathogen is even greater considering the emergence and spread of multi-resistant and potentially more pathogenic strains. In this study, the antimicrobial susceptibility profile and the presence of virulence genes spvC, invA, sefA and pefA were examined in 237 Salmonella strains belonging to 50 serovars, isolated from foods associated and nonassociated to foodborne disease outbreaks. The gene invA was detected in all Salmonella strains. The genes spvC and pefA were found in 48.1% and 44.3% of strains, respectively. The sefA gene was found in 31.6% of strains and detected only in S. Enteritidis strains. According to the presence of virulence genes, S. Enteritidis strains were grouped in into three profiles, being the one consisting of four virulence genes the most common profile (90.7%). Among strains, 46.8% were sensitive to all antibiotics, 51.9% resistant to at least one drug and 1.3% of the strains presented intermediate resistance. Multi-resistance was seen in 10.5% of the strains. The highest rates of resistance were observed for streptomycin (35.9%), nalidixic acid (16.9%), tetracycline (5.9%) and gentamicin (4.6%). No resistance was observed to cefoxitin, cephalothin, cefotaxime, amikacin, ciprofloxaxina and imipenem. The results of this study show the wide distribution of virulence genes and occurrence of antimicrobial resistance in strains both associated and non-associated to foodborne disease outbreaks, being poultry products the major sources of Salmonella with these characteristics.
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Perfil de susceptibilidade antimicrobiana e genes de virulência em cepas de Salmonella spp. isoladas de alimentos associados ou não à toxinfecções alimentares / Antimicrobial resistance profile and virulence genes in Salmonella spp. strains isolated from foods associated and non-associated to foodborne disease outbreaksRowlands, Ruth Estela Gravato 12 June 2008 (has links)
Salmonella é o agente etiológico mais comumente envolvido em casos e surtos de doenças diarréicas de origem alimentar no Brasil e outros países. A preocupação com este patógeno é, ainda, maior quando se verifica o surgimento e disseminação de cepas multi-resistentes e potencialmente mais patogênicas. O presente estudo teve como objetivo caracterizar 237 cepas Salmonella spp. distribuídas entre 50 sorovares diferentes, isoladas de alimentos associados e não associados à toxinfecções alimentares, quanto ao perfil de susceptibilidade antimicrobiana e presença dos genes de virulência spvC, invA, sefA e pefA. O gene invA foi detectado em todas as cepas de Salmonella. Com relação aos demais genes estudados, spvC e pefA foram encontrados em 48,1% e 44,3% das cepas, respectivamente. O gene sefA foi detectado em 31,6% das cepas, estando presente somente entre as cepas de S. Enteritidis. Ainda com relação à presença dos genes de virulência, as cepas de S. Enteritidis foram classificadas em três perfis, com predominância (90,7%) do perfil constituído pelos quatro genes de virulência. Quanto ao perfil de susceptibilidade antimicrobiana, 46,8% do total de cepas avaliadas foram sensíveis a todos os agentes antimicrobianos, 51,9% resistentes à pelo menos uma droga e 1,3% das cepas apresentaram apenas resistência intermediária. Multi-resistência foi observada em 10,5% das cepas. As maiores taxas de resistência foram observadas para estreptomicina (35,9%), ácido nalídixico (16,9%), tetraciclina (5,9%) e gentamicina (4,6%). Não foram detectadas cepas resistentes à cefoxitina, cefalotina, cefotaxima, amicacina, ciprofloxaxina e imipenem. Os resultados do presente estudo mostram a ampla distribuição dos genes de virulência e ocorrência de resistência antimicrobiana tanto nas cepas associadas a surtos como naquelas não envolvidas em toxinfecções alimentares, sendo os produtos de origem avícola fontes importantes de Salmonella com estas características. / Salmonella is the most common causative agent of cases and outbreaks of foodborne diarrhoeal diseases in Brazil and other countries. The concern with this pathogen is even greater considering the emergence and spread of multi-resistant and potentially more pathogenic strains. In this study, the antimicrobial susceptibility profile and the presence of virulence genes spvC, invA, sefA and pefA were examined in 237 Salmonella strains belonging to 50 serovars, isolated from foods associated and nonassociated to foodborne disease outbreaks. The gene invA was detected in all Salmonella strains. The genes spvC and pefA were found in 48.1% and 44.3% of strains, respectively. The sefA gene was found in 31.6% of strains and detected only in S. Enteritidis strains. According to the presence of virulence genes, S. Enteritidis strains were grouped in into three profiles, being the one consisting of four virulence genes the most common profile (90.7%). Among strains, 46.8% were sensitive to all antibiotics, 51.9% resistant to at least one drug and 1.3% of the strains presented intermediate resistance. Multi-resistance was seen in 10.5% of the strains. The highest rates of resistance were observed for streptomycin (35.9%), nalidixic acid (16.9%), tetracycline (5.9%) and gentamicin (4.6%). No resistance was observed to cefoxitin, cephalothin, cefotaxime, amikacin, ciprofloxaxina and imipenem. The results of this study show the wide distribution of virulence genes and occurrence of antimicrobial resistance in strains both associated and non-associated to foodborne disease outbreaks, being poultry products the major sources of Salmonella with these characteristics.
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Risk Factors and Food-Borne Illness: An Analysis of Restaurant Violations in GeorgiaHarris, Jovan 01 January 2015 (has links)
Restaurant managers complete certification in food safety in order to ensure that food is handled and prepared in a manner that decreases risk factors associated with food-borne illness. However, the literature has been inconclusive concerning the connection between manager certification and the incidence of critical food-safety violations. The purpose of this quantitative study was to examine the relationship between the presence or absence of a certified food safety manager (CFSM) and the number of risk factors cited on food inspection reports and the food safety score. In addition, this study was designed to determine whether operation type (i.e., chain vs. independently owned) has an impact on the number of risk factors and food safety score. This study was an analysis of 2013 data from 1,547 restaurants in North, Central, and South Georgia health districts using a 2-tailed independent-sample t test. Restaurants with a CFSM had significantly more risk factors cited on food safety inspections and lower food safety scores than restaurants without a CFSM. There was also a significant difference among chain and independent restaurants. Chain restaurants had fewer risk factors cited on restaurant inspections and had higher food safety scores. In the epidemiological triangle model, breaking the chain of transmission disrupts the link among agent, host, and environment. Thus, CFSMs have the responsibility to implement food safety training programs to break the chain of transmission by identifying and correcting unsafe food practices among food workers. This study has the potential to assist managers in understanding the importance of food safety and implementing food safety training programs that decrease risk factors associated with food-borne illness. Further research is needed to explore the effectiveness of manager certification in reducing critical violations.
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A multi-criteria approach to the evaluation of food safety interventions.Dunn, Alexander Hiram January 2015 (has links)
New Zealand faces a range of food safety hazards. Microbial hazards alone were estimated to cause over 2,000 years of lost healthy life in 2011 (Cressey, 2012) and $62m in medical costs and lost productivity in 2009 (Gadiel & Abelson, 2010).
Chemical hazards are thought to be well managed through existing controls (Vannoort & Thomson, 2009) whereas microbial hazards are considered harder to control, primarily due to their ability to reproduce along the food production chain. Microbial hazards are thought to cause the majority of acute foodborne gastroenteritis.
This research reviewed food safety literature and official documentation, and conducted 55 interviews, mostly with food safety experts from different stakeholder groups, to examine the food safety decision-making environment in New Zealand. This research explores the concept of the ‘stakeholder’ in the context of food safety decision-making and proposes an inclusive ‘stakeholder’ definition as any group which is able to affect, or be affected by, the decision-making process. Utilising this definition, and guided by interviews, New Zealand stakeholders in food safety decision-making were identified and classified as follows:
•Regulators
•Public health authorities
•Food safety scientists/academics
•Consumers
•Māori
•Food Businesses (further classified as):
o Farmers
o Processors
o Food retailers
o Exporters
Interviews with stakeholders from these groups highlighted twelve criteria as being relevant to multiple groups during food safety intervention evaluation:
•Effectiveness
•Financial cost
•Market Access
•Consumer Perceptions
•Ease of Implementation
•Quality or Suitability
•Quality of Science
•Equity of Costs
•Equity of Benefits
•Workplace Safety
•Cultural Impact
•Animal Welfare
There are a number of different ways to measure or assess performance on these criteria. Some are able to be quantitatively measured, while others may require the use of value judgements. This thesis used the Disability-Adjusted Life Year (DALY) metric for quantifying effectiveness during the testing of different MCDA models.
This thesis reviews the MCDA process and the food safety specific MCDA literature. There are different ways of conducting MCDA. In particular, there are a large number of models available for the aggregation phase; the process of converting model inputs, in the form of criteria scores and weights, into model recommendations. This thesis has described and reviewed the main classes of model.
The literature review and interview process guided the construction and testing of three classes of MCDA model; the Weighted Sum, Analytic Hierarchy Process (AHP) and PROMETHEE models. These models were selected due to their having different characteristics and degrees of complexity, as well as their popularity in the food safety and Health Technology Assessment (HTA) literature. Models were tested on the problem of selecting the most appropriate intervention to address the historic Campylobacter in poultry problem in New Zealand during the mid-2000s. Experimentation was conducted on these models to explore how different configurations utilise data and produce model outputs. This experimentation included:
•Varying the format of input data
•Exploring the effects of including/excluding criteria
•Methods for sensitivity analysis
•Exploring how data inputs and outputs can be elicited and presented using visual tools
• Creating and using hybrid MCDA models
The results of this testing are a key output of this thesis and provide insight into how such models might be used in food safety decision-making. The conclusions reached throughout this research phase can be classified into one of two broad groups:
•Those relating to MCDA as a holistic process/methodology for decision-making
•Those relating to the specific models and mathematical procedures for generating numerical inputs and outputs
This thesis demonstrates that food-safety decision-making is a true multi-criteria, multi-stakeholder problem. The different stakeholders in food-safety decision-making do not always agree on the value and importance of the attributes used to evaluate competing intervention schemes. MCDA is well suited to cope with such complexity as it provides a structured methodology for the systematic and explicit identification, recording and aggregation of qualitative and quantitative information, gathered from a number of different sources, with the output able to serve as a basis for decision-making.
The MCDA models studied in this thesis range from models that are simple and quick to construct and use, to more time consuming models with sophisticated algorithms. The type of model used for MCDA, the way these models are configured and the way inputs are generated or elicited can have a significant impact on the results of an analysis. This thesis has identified a number of key methodological considerations for those looking to employ one of the many available MCDA models. These considerations include:
•Whether a model can accommodate the type and format of input data
•The desired degree of compensation between criteria (i.e. full, partial or no compensation)
•Whether the goal of an analysis is the identification of a ‘best’ option(s), or the facilitation of discussion, and communication of data
•The degree of transparency required from a model and whether an easily understood audit trail is desired/required
•The desired output of a model (e.g. complete or partial ranking).
This thesis has also identified a number of practical considerations when selecting which model to use in food safety decision-making. These include:
•The amount of time and energy required of stakeholders in the generation of data inputs (elicitation burden)
•The degree of training required for participants
•How data inputs are to be elicited and aggregated in different group decision-making environments
•The availability of MCDA software for assisting an analysis
Considering the above points will assist users in selecting a suitable MCDA model that meets their requirements and constraints.
This thesis provides original and practical knowledge to assist groups or individuals looking to employ MCDA in the context of food-safety intervention decision-making. This research could also serve as a guide for those looking to evaluate a different selection of MCDA models.
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Epidemiological investigations of surveillance strategies of zoonotic Salmonella : a dissertation presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy at Massey UniversityBenschop, Jacqueline January 2009 (has links)
This thesis is concerned with the application of recently developed epidemiological and statistical tools to inform the optimisation of a national surveillance strategy of considerable importance to human health. The results of a series of epidemiological investigations of surveillance strategies for zoonotic Salmonella are presented. Salmonella are one of the most common and serious zoonotic foodborne pathogenic bacteria globally. These studies were motivated by the increasing focus on the cost-effectiveness of surveillance while maintaining consumer confidence in food supply. Although data from the Danish Salmonella surveillance and control programme has been used in these investigations, the techniques may be readily applied to other surveillance data of similar quality. The first study describes the spatial epidemiological features of Danish Salmonella surveillance and control programme data from 1995 to 2004, using a novel method of spatially adaptive smoothing. The conditional probability of a farm being a case was consistently high in the the south-west of Sonderjylland on the Jutland peninsula, identifying this area for further investigation and targeted surveillance. The identification of clustering of case farms led into the next study, which closely examines one year of data, 2003, for patterns of spatial dependency. K-function analyses provided evidence for aggregation of Salmonella case farms over that of all farms at distances of up to six kilometres. Visual semivariogram analyses of random farm-level effects from a Bayesian logistic regression model (adjusted for herd size) of Salmonella seropositivity, revealed spatial dependency between pairs of farms up to a distance of four kilometres apart. The strength of the spatial dependency was positively associated with slaughter pig farm density. We describe how this might inform the surveillance programme by potentially targeting herds within a four kilometre radius of those with high levels of Salmonella infection. In the third study, farm location details, routinely recorded surveillance information, and industry survey data from 1995 were combined to build a logistic seroprevalence model. This identified wet-feeding and specific pathogen free herd health status as protective factors for Salmonella seropositivity, while purchasing feed was a risk factor. Once adjusting for these covariates, we identified pockets of unexplained risk for Salmonella seropositivity and found spatial dependency at distances of up to six km (95% CI: 2–35 km) between farms. A generalised linear spatial model was fitted to the Jutland data allowing formal estimation of the range of spatial correlation and a measure of the uncertainty about it. There was a large within-farm component to the variance, suggesting that gathering more farm level information would be advantageous if this approach was to be used to target surveillance strategy. The fourth study again considers data from the whole study period, 1995 to 2004. A detailed temporal analysis of the data revealed there was no consistent seasonal pattern and correspondingly no benefit in targeting sampling to particular times of the year. Spatiotemporal analyses suggested a local epidemic of increased seroprevalence occured in west Jutland in late 2000. Lorelogram analyses showed a defined period of statistically significant temporal dependency, suggesting that there is little value in sampling more frequently than every 10 weeks on the average farm. The final study uses findings from the preceding chapters to develop a zero-inflated binomial model which predicts which farms are most at risk of Salmonella, and then preferentially samples these high-risk farms. This type of modelling allows assessment of similarities and differences between factors that affect herd infection status (introduction) and those that affect the seroprevalence in infected herds (persistence and spread). The model suggested that many of the herds where Salmonella was not detected were infected but at a low prevalence. Using cost and sensitivity, we compared the results with those under the standard sampling scheme based on herd size, and the recently introduced risk-based approach. Model based results were less sensitive, but showed significant cost savings. Further model refinements, sampling schemes, and the methods to evaluate their performance are important areas for future work, and should continue to occur in direct consultation with Danish authorities.
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Epidemiological investigations of surveillance strategies of zoonotic Salmonella : a dissertation presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy at Massey UniversityBenschop, Jacqueline January 2009 (has links)
This thesis is concerned with the application of recently developed epidemiological and statistical tools to inform the optimisation of a national surveillance strategy of considerable importance to human health. The results of a series of epidemiological investigations of surveillance strategies for zoonotic Salmonella are presented. Salmonella are one of the most common and serious zoonotic foodborne pathogenic bacteria globally. These studies were motivated by the increasing focus on the cost-effectiveness of surveillance while maintaining consumer confidence in food supply. Although data from the Danish Salmonella surveillance and control programme has been used in these investigations, the techniques may be readily applied to other surveillance data of similar quality. The first study describes the spatial epidemiological features of Danish Salmonella surveillance and control programme data from 1995 to 2004, using a novel method of spatially adaptive smoothing. The conditional probability of a farm being a case was consistently high in the the south-west of Sonderjylland on the Jutland peninsula, identifying this area for further investigation and targeted surveillance. The identification of clustering of case farms led into the next study, which closely examines one year of data, 2003, for patterns of spatial dependency. K-function analyses provided evidence for aggregation of Salmonella case farms over that of all farms at distances of up to six kilometres. Visual semivariogram analyses of random farm-level effects from a Bayesian logistic regression model (adjusted for herd size) of Salmonella seropositivity, revealed spatial dependency between pairs of farms up to a distance of four kilometres apart. The strength of the spatial dependency was positively associated with slaughter pig farm density. We describe how this might inform the surveillance programme by potentially targeting herds within a four kilometre radius of those with high levels of Salmonella infection. In the third study, farm location details, routinely recorded surveillance information, and industry survey data from 1995 were combined to build a logistic seroprevalence model. This identified wet-feeding and specific pathogen free herd health status as protective factors for Salmonella seropositivity, while purchasing feed was a risk factor. Once adjusting for these covariates, we identified pockets of unexplained risk for Salmonella seropositivity and found spatial dependency at distances of up to six km (95% CI: 2–35 km) between farms. A generalised linear spatial model was fitted to the Jutland data allowing formal estimation of the range of spatial correlation and a measure of the uncertainty about it. There was a large within-farm component to the variance, suggesting that gathering more farm level information would be advantageous if this approach was to be used to target surveillance strategy. The fourth study again considers data from the whole study period, 1995 to 2004. A detailed temporal analysis of the data revealed there was no consistent seasonal pattern and correspondingly no benefit in targeting sampling to particular times of the year. Spatiotemporal analyses suggested a local epidemic of increased seroprevalence occured in west Jutland in late 2000. Lorelogram analyses showed a defined period of statistically significant temporal dependency, suggesting that there is little value in sampling more frequently than every 10 weeks on the average farm. The final study uses findings from the preceding chapters to develop a zero-inflated binomial model which predicts which farms are most at risk of Salmonella, and then preferentially samples these high-risk farms. This type of modelling allows assessment of similarities and differences between factors that affect herd infection status (introduction) and those that affect the seroprevalence in infected herds (persistence and spread). The model suggested that many of the herds where Salmonella was not detected were infected but at a low prevalence. Using cost and sensitivity, we compared the results with those under the standard sampling scheme based on herd size, and the recently introduced risk-based approach. Model based results were less sensitive, but showed significant cost savings. Further model refinements, sampling schemes, and the methods to evaluate their performance are important areas for future work, and should continue to occur in direct consultation with Danish authorities.
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