ABSTRACT
Cronobacter sakazakii is a potentially pathogenic bacterium that is resistant to osmotic stress and low aw, and capable of persisting in a desiccated state in powdered infant milks. It is widespread in the environment and present in various products. Despite the low incidence of cases, its high mortality rates of 40 to 80 % amongst neonates make it a microorganism of public health interest. This current study performed a comparative assessment between current reduction methods applied for C. sakazakii in various food matrices, indicating tendencies and relevant parameters for process optimization. A systematic review and meta-analysis were conducted, qualitatively identifying the main methods of inactivation and control, and quantitatively evaluating the effect of treatment factors on the reduction response. Hierarchical clustering dendrograms led to conclusions on the efficiency of each treatment. Review of recent research trend identified a focus on the potential use of alternative treatments, with most studies related to non-thermal methods and dairy products. Using random-effects meta-analysis, a summary effect-size of 4-log was estimated; however, thermal methods and treatments on dairy matrices displayed wider dispersions - of τ2 = 8.1, compared with τ2 = 4.5 for vegetal matrices and τ2 = 4.0 for biofilms. Meta-analytical models indicated that factors such as chemical concentration, energy applied, and treatment time had a more significant impact on reduction than the increase in temperature. Non-thermal treatments, synergically associated with heat, and treatments on dairy matrices were found to be the most efficient.
Subject(s)
Cronobacter sakazakii , Food Microbiology , Cronobacter sakazakii/growth & development , Food Contamination/prevention & control , Food Contamination/analysis , Humans , Dairy Products/microbiology , Food Handling/methods , Biofilms/growth & development , AnimalsABSTRACT
In this study, different dairy products such as ice cream, yoghurt, white pickled cheese, and fermented acidophilus milk were manufactured by using either Lactobacillus acidophilus DSM 20,079 or Lactobacillus acidophilus NCFM. The counts of L. acidophilus in the samples on days 1, 15, and 30 of the storage were determined. Additionally, the samples contained L. acidophilus were passed through a dynamic gastrointestinal model designed in laboratory conditions to compare the protective effect of different dairy products on viability of L. acidophilus against stress factors of the gastrointestinal model. The counts of L. acidophilus NCFM and L. acidophilus DSM 20,079 in the samples decreased by between 0.04 and 0.37 log units and by between 0.11 and 0.27 log units, respectively, within 30 days of storage. During the passage through the gastrointestinal model, the highest percentage reduction in the counts of L. acidophilus was determined in yoghurt followed by fermented acidophilus milk, white pickled cheese, and ice cream, respectively. The reduction in the counts of L. acidophilus in the samples during the passage through the model increased with extension of storage time. The results of this study showed that the reduction in the counts L. acidophilus in the samples during the passage through the model was influenced significantly by the matrix of the dairy product and storage period.
Subject(s)
Dairy Products/microbiology , Gastrointestinal Tract/microbiology , Lactobacillus acidophilus , Probiotics , Animals , Cheese/microbiology , Lactobacillus acidophilus/physiology , Milk/microbiology , Models, Biological , Time Factors , Yogurt/microbiologyABSTRACT
In an age of flexible conditions about mandatory milk pasteurisation, this opinion-based research reflection supports the view that the knowledge and the awareness of milk-borne infections are key requirements to decrease the risks associated with raw milk. Providing an analysis of the current potential risks related to consumption of raw milk and raw milk products, we discuss the main reasons to continue to be vigilant about milk-borne pathogens and the current scenario in relation to the formal and clandestine sale of raw milk. Finally, we select some highly effective strategies to reduce the risks associated with raw milk in food services. Regardless of whether a country regulation allows or prohibits the trade of raw milk and its products, this is not the time to be negligent.
Subject(s)
Health Knowledge, Attitudes, Practice , Milk/microbiology , Pasteurization , Animals , Brucella , Consumer Behavior , Dairy Products/microbiology , Dairying , Enterotoxins , Food Microbiology , Food Safety , Food Services , Foodborne Diseases/microbiology , Humans , Risk FactorsABSTRACT
Alternative methods for improving traditional food processing have increased in the last decades. Additionally, the development of novel dairy products is gaining importance due to an increased consumer demand for palatable, healthy, and minimally processed products. Ultrasonic processing or sonication is a promising alternative technology in the food industry as it has potential to improve the technological and functional properties of milk and dairy products. This review presents a detailed summary of the latest research on the impact of high-intensity ultrasound techniques in dairy processing. It explores the ways in which ultrasound has been employed to enhance milk properties and processes of interest to the dairy industry, such as homogenization, emulsification, yogurt and fermented beverages production, and food safety. Special emphasis has been given to ultrasonic effects on milk components; fermentation and spoilage by microorganisms; and the technological, functional, and sensory properties of dairy foods. Several current and potential applications of ultrasound as a processing technique in milk applications are also discussed in this review.
Subject(s)
Dairy Products , Food Microbiology , Sonication , Taste , Dairy Products/microbiology , Dairy Products/standards , Fermentation , HumansABSTRACT
The influence of two autochthonous lactobacilli strains with probiotic potential (Lactobacillus mucosae CNPC007 and Lactobacillus plantarum CNPC020) in comparison to a commercially available probiotic strain (Lactobacillus rhamnosus LR32) in non-fermented dairy desserts added with ingredients (syrup and hydroethanolic extract) derived from jabuticaba (Myrciaria cauliflora) peels was investigated. L. mucosae showed the best survivability and stability of the studied lactobacilli after processing and during storage, respectively, and also remarkably influenced the texture and sensory features of desserts in comparison to the other strains; L. plantarum achieved viability comparable with the commercial probiotic, above 6 log cfu/g up to the 21st day of the products refrigerated storage. The hydroethanolic extract and syrup from the jabuticaba peel contributed to the phenolic content of the dairy desserts (around 30 mg GAE/100 g) that showed to be able to scavenge DPPH radicals (around 300 g dessert/g DPPH). The different lactobacilli strains did not significantly influence the antioxidant capacity parameters of the desserts (p > 0.05), although the desserts' color was not stable during storage and tended to reduce the acceptability scores of the three trials. Non-fermented dairy desserts with jabuticaba peel ingredients showed to be good sources of phenolic compounds with an antioxidant capacity, offering suitable conditions for the viability maintenance of the autochthonous lactobacilli cultures.
Subject(s)
Antioxidants , Dairy Products/microbiology , Lactobacillaceae , Myrtaceae/chemistry , Plant Extracts , Probiotics , Fruit/chemistryABSTRACT
Coalho cheese is a typical Northeastern Brazilian food whose production and consumption has expanded considerably to other regions of the country. Despite its cultural and socioeconomic relevance, coalho cheese still has a negative reputation due to problems in its physicochemical and microbiological quality standards, especially when it is produced artisanally. For this reason, many researchers have been looking for alternatives to improve the quality and the notoriety of this product, such as the application of probiotic strains to inhibit pathogens. However, in addition to the research related to the desired probiotic properties and the safety of strains for food application, it is important to know the possible changes in the food matrix caused by this intervention. In this context, the aim of this study was to evaluate the effect of the incorporation of probiotic strains of Enterococcus faecium on the physicochemical and sensory characteristics of coalho cheese. The cheeses were made with pasteurized cow milk and probiotic strains of E. faecium were added during production. Cheeses were also made without adding the strains, and considered as control cheeses. The final products were evaluated for moisture, pH, titratable acidity, total carbohydrates, proteins, lipids, ash, color, organic acid profile, and sensory attributes.
O queijo coalho é um queijo típico do Nordeste do Brasil, cuja produção e consumo se expandiram consideravelmente para outras regiões do país. Apesar de sua relevância cultural e socioeconômica, o queijo coalho apresenta uma reputação negativa, devido a problemas em seus padrões de qualidade físicoquímicos e microbiológicos, principalmente quando é produzido artesanalmente. Por esse motivo, muitos pesquisadores têm buscado alternativas para melhoria da qualidade e notabilidade desse produto, como a aplicação de cepas probióticas que inibem patógenos. No entanto, além da investigação relacionada às propriedades probióticas desejadas e de segurança das cepas para aplicação em alimentos, é importante conhecer as possíveis alterações na matriz alimentícia em virtude dessa adição. Nesse contexto, o objetivo deste estudo foi avaliar o efeito da incorporação de cepas probióticas de Enterococcus faecium nas características físico-químicas e sensoriais de queijo coalho. Os queijos foram elaborados com leite de vaca pasteurizado e adicionados de cepas probióticas de E. faecium durante a produção. Também foram elaborados queijos sem adição das cepas, considerados queijos controle. Os produtos finais foram avaliados quanto a umidade, pH, acidez titulável, carboidratos totais, proteínas, lipídios, cinzas, cor, perfil de ácidos orgânicos e atributos sensoriais. Além disso, procedeu-se a contagem de bactérias ácido lácticas viáveis. Os queijos coalho adicionados de E. faecium apresentaram maior acidez titulável e menor pH. Além disso, houve uma redução no teor de carboidratos, atribuída à degradação da lactose. O. perfil de ácidos orgânicos também variou, destacando-se pelo aumento da concentração de ácido láctico em um fator de 3,5 e pela ausência de ácido cítrico, como possível resultado do metabolismo de E. faecium na produção de compostos aromáticos
Subject(s)
Enterococcus faecium/chemistry , Chemical Phenomena , Dairy Products/analysis , Dairy Products/microbiology , Probiotics/analysis , Probiotics/chemistry , Cheese/analysisABSTRACT
Coalho cheese is a typical Northeastern Brazilian food whose production and consumption has expanded considerably to other regions of the country. Despite its cultural and socioeconomic relevance, coalho cheese still has a negative reputation due to problems in its physicochemical and microbiological quality standards, especially when it is produced artisanally. For this reason, many researchers have been looking for alternatives to improve the quality and the notoriety of this product, such as the application of probiotic strains to inhibit pathogens. However, in addition to the research related to the desired probiotic properties and the safety of strains for food application, it is important to know the possible changes in the food matrix caused by this intervention. In this context, the aim of this study was to evaluate the effect of the incorporation of probiotic strains of Enterococcus faecium on the physicochemical and sensory characteristics of coalho cheese. The cheeses were made with pasteurized cow milk and probiotic strains of E. faecium were added during production. Cheeses were also made without adding the strains, and considered as control cheeses. The final products were evaluated for moisture, pH, titratable acidity, total carbohydrates, proteins, lipids, ash, color, organic acid profile, and sensory attributes.(AU)
O queijo coalho é um queijo típico do Nordeste do Brasil, cuja produção e consumo se expandiram consideravelmente para outras regiões do país. Apesar de sua relevância cultural e socioeconômica, o queijo coalho apresenta uma reputação negativa, devido a problemas em seus padrões de qualidade físicoquímicos e microbiológicos, principalmente quando é produzido artesanalmente. Por esse motivo, muitos pesquisadores têm buscado alternativas para melhoria da qualidade e notabilidade desse produto, como a aplicação de cepas probióticas que inibem patógenos. No entanto, além da investigação relacionada às propriedades probióticas desejadas e de segurança das cepas para aplicação em alimentos, é importante conhecer as possíveis alterações na matriz alimentícia em virtude dessa adição. Nesse contexto, o objetivo deste estudo foi avaliar o efeito da incorporação de cepas probióticas de Enterococcus faecium nas características físico-químicas e sensoriais de queijo coalho. Os queijos foram elaborados com leite de vaca pasteurizado e adicionados de cepas probióticas de E. faecium durante a produção. Também foram elaborados queijos sem adição das cepas, considerados queijos controle. Os produtos finais foram avaliados quanto a umidade, pH, acidez titulável, carboidratos totais, proteínas, lipídios, cinzas, cor, perfil de ácidos orgânicos e atributos sensoriais. Além disso, procedeu-se a contagem de bactérias ácido lácticas viáveis. Os queijos coalho adicionados de E. faecium apresentaram maior acidez titulável e menor pH. Além disso, houve uma redução no teor de carboidratos, atribuída à degradação da lactose. O. perfil de ácidos orgânicos também variou, destacando-se pelo aumento da concentração de ácido láctico em um fator de 3,5 e pela ausência de ácido cítrico, como possível resultado do metabolismo de E. faecium na produção de compostos aromáticos(AU)
Subject(s)
Probiotics/analysis , Probiotics/chemistry , Enterococcus faecium/chemistry , Chemical Phenomena , Cheese/analysis , Dairy Products/analysis , Dairy Products/microbiologyABSTRACT
O objetivo deste estudo foi caracterizar o perfil do consumidor de produtos lácteos de origens bubalina e bovina nos municípios de Soure e Salvaterra (Ilha do Marajó-PA) quanto ao perfil sociodemográfico, ao nível de conhecimento sobre qualidade higiênico-sanitária e sobre fraudes nesses produtos. Para coleta dos dados, foram aplicados questionários a voluntários escolhidos ao acaso. Os dados foram analisados de forma descritiva e, posteriormente, submetidos à análise de correspondência múltipla (ACM). A coleta de dados resultou em 403 entrevistas. Os resultados demonstraram que os consumidores de produtos de origem bubalina eram, em sua maioria, do sexo masculino, com idade acima de 40 anos, que consomem principalmente de produtores rurais, enquanto que os consumidores de produtos bovinos eram mulheres com idades entre 21 e 30 anos, sendo os alimentos procedentes de estabelecimentos comerciais como supermercados e padarias.(AU)
The aim of this study was to characterize the profile of consumers of dairy products of buffalo and cow origins in the municipalities of Soure and Salvaterra (Ilha do Marajó-PA), regarding the sociodemographic profile, the level of knowledge about hygiene and fraud in these products. For data collection, questionnaires were applied to volunteers chosen at random. The data were analyzed descriptively and subsequently submitted to multiple correspondence analysis (MCA). The data collection resulted in 403 interviews. The results showed that the consumers of products of buffalo origin were mostly male, aged over 40 years, who consume mainly from rural producers, while the consumers of bovine products were women aged between 21 and 30 years, with food coming from commercial establishments such as supermarkets and bakeries.(AU)
El objetivo de este estudio fue caracterizar el perfil de los consumidores de productos lácteos de origen bufalino y bovino en los municipios de Soure y Salvaterra (Ilha do Marajó-PA), con respecto al perfil sociodemográfico, el nivel de conocimiento sobre la calidad higiénico-sanitaria y la existência de actos fraudulentos en estos productos. Para la recopilación de datos, se aplicaron cuestionarios a los voluntarios, elegidos al azar. Los datos fueron analizados descriptivamente y posteriormente sometidos a análisis de correspondencia múltiples (ACM). La recopilación de datos resultó en un total de 403 entrevistas. Los resultados mostraron que el consumidores de productos de origen búfalo eran en su mayoría hombres, mayores de 40 años, que consumían principalmente de productores rurales, mientras que los consumidores de productos bovinos estaban representados mayormente mujeres de 21 a 30 años, que consumían en establecimientos comerciales como supermercados y panaderías.(AU)
Subject(s)
Humans , Consumer Behavior , Dairy Products/microbiology , Socioeconomic Factors , Demographic Indicators , Food Safety , Sex Factors , Cattle , Buffaloes , BrazilABSTRACT
In Brazil, the buffalo milk market has been growing. However, identity and quality standards have not been established for this raw material, nor have proper distinctions between buffalo milk and bovine milk been defined. Currently, the State of Rio Grande do Sul (RS) has only three producers that supply raw material for officially marketed derivatives. The aim of this study was to determine the identity and quality standards of raw buffalo milk in this region. Samples were obtained biweekly from three farm cooling tanks between June 2017 and August 2018, to reach a total of 69 samples. The averages for the results of the physicochemical parameters fat, protein, lactose, total solids, SNF (solids-not-fat), calcium, density, FP, acidity and SCC were 5.5 g/100 g, 4.06 g/100 g, 5.07 g/100 g, 15.5 g/100 g, 9.96 g/100 g, 0.161 g/100 g, 1.034 g/ml, -0.527°C, 16°D and 95 × 103 cells/ml, respectively. With reference to the microbiological parameters, the mean of the Standard Plate Count (SPC) and thermotolerant coliforms were 9,0 × 104 CFU/ml and 1.6 × 102 MPN/ml, respectively. Regarding coagulase-positive staphylococci, 36 samples tested positive (52% of total). Neither Salmonella spp. nor Listeria monocytogenes, nor antibiotic or antiparasitic residues were detected in any sample. In conclusion, the buffalo milk used as raw material for dairy products in southern Brazil demonstrated satisfactory physicochemical and microbiological characteristics, in accordance with recent scientific literature.
Subject(s)
Buffaloes/physiology , Dairy Products/microbiology , Food Microbiology , Milk/chemistry , Milk/microbiology , Animals , Anti-Bacterial Agents/chemistry , Antiparasitic Agents/chemistry , Bacteria/isolation & purification , Brazil , Drug Residues/chemistryABSTRACT
For this research communication, 90 samples of a Brazilian dairy were combined into four groups (raw material, final product, food-contact and non-food contact surfaces) and analyzed by metataxonomics based on 16S rRNA gene sequencing. The results showed high alpha-diversity indexes for final product and non-food contact surfaces but, overall, beta-diversity indexes were low. The samples were separated in two main clusters, and the core microbiota was composed by Macrococcus, Alkaliphilus, Vagococcus, Lactobacillus, Marinilactibacillus, Streptococcus, Lysinibacillus, Staphylococcus, Clostridium, Halomonas, Lactococcus, Enterococcus, Bacillus and Psychrobacter. These results highlight that rare taxa occur in dairies, and this may aid the development of strategies for food protection.
Subject(s)
Bacteria/classification , Dairy Products/microbiology , Food Microbiology , Milk/microbiology , Animals , Bacteria/genetics , Brazil , CattleABSTRACT
Antimicrobial resistance is a worldwide public health threat. Farm animals are important sources of bacteria containing antimicrobial resistance genes (ARGs). Although the use of antimicrobials in aquaculture and livestock has been reduced in several countries, these compounds are still routinely applied in animal production, and contribute to ARGs emergence and spread among bacteria. ARGs are transmitted to humans mainly through the consumption of products of animal origin (PAO). Bacteria can present intrinsic resistance, and once antimicrobials are administered, this resistance may be selected and multiply. The exchange of genetic material is another mechanism used by bacteria to acquire resistance. Some of the main ARGs found in bacteria present in PAO are the bla, mcr-1, cfr and tet genes, which are directly associated to antibiotic resistance in the human clinic.
Subject(s)
Animals, Domestic/microbiology , Anti-Bacterial Agents/adverse effects , Bacteria/genetics , Drug Resistance, Bacterial/genetics , Food Microbiology , Agriculture , Animals , Bacteria/drug effects , Bacteria/metabolism , Dairy Products/microbiology , Drug Resistance, Bacterial/drug effects , Eggs/microbiology , Humans , Meat/microbiologyABSTRACT
Probiotic dairy beverages prepared from buffalo and cow milks with different levels of whey (0, 25, and 50%) were evaluated for kinetic fermentation parameters, protein and fat contents, post-acidification profile, viability of Streptococcus thermophilus, Lactobacillus bulgaricus, and Lactobacillus acidophilus during 21 d of refrigerated storage, and resistance to in vitro gastrointestinal conditions. Progressive acidification that occurred during storage of all dairy products was reduced in the presence of whey. Lactic acid bacteria showed viable cell counts at the end of shelf life, with the highest values (7.33 to 8.83 log cfu/mL) detected in buffalo dairy products. Compared with fermented cow milk products, those made with buffalo milk showed better bacterial viability during in vitro simulated gastrointestinal digestion, which suggests a beneficial protective effect on human microbiome.
Subject(s)
Buffaloes , Dairy Products/microbiology , Gastrointestinal Tract/metabolism , Microbial Viability , Milk , Probiotics , Animals , Beverages , Cattle , Cultured Milk Products/microbiology , Female , Fermentation , Food Storage , Humans , Lactobacillus acidophilus/metabolism , Microbiota , Milk/metabolism , Probiotics/analysis , Streptococcus thermophilus/metabolism , Whey Proteins/analysisABSTRACT
O objetivo deste estudo foi caracterizar o perfil do consumidor de produtos lácteos de origens bubalina e bovina nos municípios de Soure e Salvaterra (Ilha do Marajó-PA) quanto ao perfil sociodemográfico, ao nível de conhecimento sobre qualidade higiênico-sanitária e sobre fraudes nesses produtos. Para coleta dos dados, foram aplicados questionários a voluntários escolhidos ao acaso. Os dados foram analisados de forma descritiva e, posteriormente, submetidos à análise de correspondência múltipla (ACM). A coleta de dados resultou em 403 entrevistas. Os resultados demonstraram que os consumidores de produtos de origem bubalina eram, em sua maioria, do sexo masculino, com idade acima de 40 anos, que consomem principalmente de produtores rurais, enquanto que os consumidores de produtos bovinos eram mulheres com idades entre 21 e 30 anos, sendo os alimentos procedentes de estabelecimentos comerciais como supermercados e padarias.
The aim of this study was to characterize the profile of consumers of dairy products of buffalo and cow origins in the municipalities of Soure and Salvaterra (Ilha do Marajó-PA), regarding the sociodemographic profile, the level of knowledge about hygiene and fraud in these products. For data collection, questionnaires were applied to volunteers chosen at random. The data were analyzed descriptively and subsequently submitted to multiple correspondence analysis (MCA). The data collection resulted in 403 interviews. The results showed that the consumers of products of buffalo origin were mostly male, aged over 40 years, who consume mainly from rural producers, while the consumers of bovine products were women aged between 21 and 30 years, with food coming from commercial establishments such as supermarkets and bakeries.
El objetivo de este estudio fue caracterizar el perfil de los consumidores de productos lácteos de origen bufalino y bovino en los municipios de Soure y Salvaterra (Ilha do Marajó-PA), con respecto al perfil sociodemográfico, el nivel de conocimiento sobre la calidad higiénico-sanitaria y la existência de actos fraudulentos en estos productos. Para la recopilación de datos, se aplicaron cuestionarios a los voluntarios, elegidos al azar. Los datos fueron analizados descriptivamente y posteriormente sometidos a análisis de correspondencia múltiples (ACM). La recopilación de datos resultó en un total de 403 entrevistas. Los resultados mostraron que el consumidores de productos de origen búfalo eran en su mayoría hombres, mayores de 40 años, que consumían principalmente de productores rurales, mientras que los consumidores de productos bovinos estaban representados mayormente mujeres de 21 a 30 años, que consumían en establecimientos comerciales como supermercados y panaderías.
Subject(s)
Humans , Consumer Behavior , Sex Factors , Socioeconomic Factors , Demographic Indicators , Food Safety , Dairy Products/microbiology , Cattle , Brazil , BuffaloesABSTRACT
Dulce de leche is the product obtained by concentrating milk and adding sucrose. This sweet can be contaminated by improper practices during the manufacturing process, or in the consumers home. If manipulation is not performed in a hygienic manner the dulce de leche can be a vehicle of pathogenic bacteria, like some strains of Escherichia coli, to man. The aim of this paper was evaluate the survival capacity and the fate of Escherichia coli Enteroinvasive, Enteropathogenic and Enterohemorrhagic in pasty dulce de leche. Aliquots of this sweet were experimentally contaminated with these pathogenic microorganisms at 102 bacterial cells per gram, and later analyzed to evaluate microorganism count after storage for 0, 1, 2, 3, 5, 10, 20 and 30 days. EIEC could be recovered up to 20 days post inoculation in one of the reps, count EIEC on the third day reached 1,500 MPN per g. The strains of EPEC and EHEC, did not show growth, as EIEC, therefore, seem to be more sensitive to the adversities of the medium. The survival of pathogens for long periods in this food highlights the need for strict care in the manufacture and handling of dulce de leche.
O doce de leite é um alimento obtido por concentração do leite adicionado de sacarose. Este alimento pode ser contaminado por práticas inadequadas durante o processamento. Caso a manipulação não seja realizada de maneira higiênica o alimento pode ser veículo de bactérias patogênicas, como algumas cepas de Escherichia coli, para o homem. O objetivo desse trabalho foi avaliar a capacidade de sobrevivência e o comportamento de EIEC, EPEC e EHEC em doce de leite pastoso. Alíquotas deste doce foram experimentalmente contaminadas com esse micro-organismo patogênico na concentração 102 células por grama e posteriormente analisados para avaliar a contagem bacteriana após 0, 1, 2, 3, 5, 10, 20 e 30 dias de estocagem. EIEC pôde ser recuperada até 20 dias após a inoculação em duas das três repetições. Em uma das repetições, a contagem de EIEC no terceiro dia atingiu 1.500 NMP por g. As cepas de EPEC e EHEC, não apresentaram crescimento, como EIEC, portanto, parecerem ser mais sensíveis às adversidades do meio. A sobrevivência desses patógenos durante dias neste alimento evidencia a necessidade de rigorosos cuidados na fabricação e manuseio do doce de leite pastoso.
Subject(s)
Colimetry/analysis , Escherichia coli , Dairy Products/analysis , Dairy Products/microbiology , Food SupplyABSTRACT
Dulce de leche is the product obtained by concentrating milk and adding sucrose. This sweet can be contaminated by improper practices during the manufacturing process, or in the consumers home. If manipulation is not performed in a hygienic manner the dulce de leche can be a vehicle of pathogenic bacteria, like some strains of Escherichia coli, to man. The aim of this paper was evaluate the survival capacity and the fate of Escherichia coli Enteroinvasive, Enteropathogenic and Enterohemorrhagic in pasty dulce de leche. Aliquots of this sweet were experimentally contaminated with these pathogenic microorganisms at 102 bacterial cells per gram, and later analyzed to evaluate microorganism count after storage for 0, 1, 2, 3, 5, 10, 20 and 30 days. EIEC could be recovered up to 20 days post inoculation in one of the reps, count EIEC on the third day reached 1,500 MPN per g. The strains of EPEC and EHEC, did not show growth, as EIEC, therefore, seem to be more sensitive to the adversities of the medium. The survival of pathogens for long periods in this food highlights the need for strict care in the manufacture and handling of dulce de leche.(AU)
O doce de leite é um alimento obtido por concentração do leite adicionado de sacarose. Este alimento pode ser contaminado por práticas inadequadas durante o processamento. Caso a manipulação não seja realizada de maneira higiênica o alimento pode ser veículo de bactérias patogênicas, como algumas cepas de Escherichia coli, para o homem. O objetivo desse trabalho foi avaliar a capacidade de sobrevivência e o comportamento de EIEC, EPEC e EHEC em doce de leite pastoso. Alíquotas deste doce foram experimentalmente contaminadas com esse micro-organismo patogênico na concentração 102 células por grama e posteriormente analisados para avaliar a contagem bacteriana após 0, 1, 2, 3, 5, 10, 20 e 30 dias de estocagem. EIEC pôde ser recuperada até 20 dias após a inoculação em duas das três repetições. Em uma das repetições, a contagem de EIEC no terceiro dia atingiu 1.500 NMP por g. As cepas de EPEC e EHEC, não apresentaram crescimento, como EIEC, portanto, parecerem ser mais sensíveis às adversidades do meio. A sobrevivência desses patógenos durante dias neste alimento evidencia a necessidade de rigorosos cuidados na fabricação e manuseio do doce de leite pastoso.(AU)
Subject(s)
Colimetry/analysis , Escherichia coli , Dairy Products/analysis , Dairy Products/microbiology , Food SupplyABSTRACT
Abstract The fidelity of the genomes is defended by mechanism known as Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) systems. Three Type II CRISPR systems (CRISPR1- cas, CRISPR2 and CRISPR3-cas) have been identified in enterococci isolates from clinical and environmental samples. The aim of this study was to observe the distribution of CRISPR1-cas, CRISPR2 and CRISPR3-cas in non-clinical strains of Enterococcus faecalis and Enterococcus faecium isolates from food and fecal samples, including wild marine animals. The presence of CRISPRs was evaluated by PCR in 120 enterococci strains, 67 E. faecalis and 53 E. faecium. It is the first report of the presence of the CRISPRs system in E. faecalis and E. faecium strains isolated from wild marine animal fecal samples. The results showed that in non-clinical strains, the CRISPRs were more frequently detected in E. faecalis than in E. faecium. And the frequencies of CRISPR1-cas and CRISPR2 were higher (60%) in E. faecalis strains isolated from animal feces, compared to food samples. Both strains showed low frequencies of CRISPR3-cas (8.95% and 1.88%). In conclusion, the differences in the habitats of enterococcal species may be related with the results observe in distribution of CRISPRs systems.
Resumo A fidelidade dos genomas é defendida por mecanismos conhecidos como sistemas de repetições palindrômicas curtas agrupadas e regularmente interespaçadas (CRISPRs). Três tipos de sistemas CRISPR II (CRISPR1-cas, CRISPR2 e CRISPR3-cas) têm sido identificados em cepas de enterococos isolados de amostras clínicas e ambientais. O objetivo deste estudo foi observar a distribuição dos CRISPR1-cas, CRISPR2 e CRISPR3-cas em cepas não-clínicas de Enterococcus faecalis e Enterococcus faecium isoladas de amostras alimentícias e fecais, incluindo animais marinhos selvagens. A presenca dos CRISPRs foi determinada por PCR em 120 cepas de enterococos, sendo 67 E. faecalis e 53 E. faecium. É o primeiro relato da presença do sistema CRISPRs nas estirpes E. faecalis e E. faecium isoladas de amostras fecais de animais marinhos selvagens. Os resultados mostraram que em cepas não-clínicas, os CRISPRs foram mais frequentemente detectados em E. faecalis do que em E. faecium. E as frequências de CRISPR1-cas e CRISPR2 foram maiores (60%) em cepas de E. faecalis isoladas de fezes de animais, quando comparadas à amostras de alimentos. Ambas as cepas apresentaram baixas freqüências de CRISPR3-cas (8,95% e 1,88%). Em conclusão, as diferenças nos habitats das espécies de enterococos podem estar relacionadas com os resultados observados na distribuição dos sistemas CRISPRs.
Subject(s)
Animals , Enterococcus faecium/genetics , Enterococcus faecalis/genetics , Feces/microbiology , Clustered Regularly Interspaced Short Palindromic Repeats , Food Microbiology , Turtles/microbiology , Vegetables/microbiology , Chickens/microbiology , Dairy Products/microbiology , Milk/microbiology , Spheniscidae/microbiology , Fur Seals/microbiology , Meat/microbiologyABSTRACT
Os diferentes grupos de E. coli podem estar presentes no leite e seus derivados, que podem resultar em infecções em humanos. Este estudo objetivou isolar E. coli de diferentes pontos da obtenção do leite e da elaboração de queijos tipo Minas frescal, detectar os patótipos EAEC, EIEC, ETEC, EPEC, STEC, ExPEC e caracterizar os isolados pela pesquisa de genes de virulência . Para tanto, foram realizadas coletas em cinco pequenas propriedades rurais produtoras deste tipo de queijo no nordeste do estado de São Paulo. Foram coletadas amostras de suabes de fezes bovinas, de mãos de ordenhador, balde, leite, soro, água, superfície de elaboração de queijos, mãos de manipulador do queijo, peneiras, bandejas, fôrmas e escumadeiras. Foram obtidos 73 isolados de E. coli potencialmente patogênicos, sendo que nas amostras de leite e queijo foram encontrados isolados como STEC e ExPEC. Assim, a presença de cepas de E. coli potencialmente patogênicas na obtenção do leite e na produção do queijo constitui risco para a saúde pública.(AU)
Subject(s)
Dairy Products/analysis , Dairy Products/microbiology , Cheese/analysis , Cheese/microbiology , Milk/microbiology , Escherichia coli/isolation & purification , Escherichia coli/pathogenicity , Food Microbiology , Food HandlingABSTRACT
Objetivou-se pesquisar presença e realizar contagem de Staphylococcus coagulase positiva e de coliformes totais e termotolerantes em amostras de queijos coalho artesanais, produzidos com leite cru e comercializados no agreste paraibano. Foram examinadas 10 peças de queijo, recolhidos aleatoriamente em diferentes pontos de comercialização. As 10 amostras examinadas apresentaram Staphylococcus spp. tendo como média 1,11x105UFC/g, todas amostras apresentaram Staphylococcus coagulase positiva. E m relação aos Coliformes termotolerantes, as 10 amostras avaliadas foram positivas acima de 10x10³ NMP/g, quando o número máximo permitido na legislação é de 5x10² NMP/g, portanto, os queijos analisados podem oferecer riscos à saúde da população, decorrente da veiculação de microrganismos patogênicos.(AU)
Subject(s)
Dairy Products/analysis , Dairy Products/microbiology , Cheese/analysis , Cheese/microbiology , Staphylococcus/isolation & purification , Food Microbiology , Food HygieneABSTRACT
Na região de Salinas, assim como no estado de Minas Gerais inteiro, a fabricação e comercialização de queijo artesanal é um hábito cultural. A venda de queijo em feira comercial ou em residências é uma prática tradicional que oferece sustento para muitos produtores da cidade mineira. O presente estudo aborda a qualidade de queijo cozido produzido por produtores da região de Salinas-MG. Foram coletadas amostras de queijos já prontos para consumo, de 10 produtores escolhidos aleatoriamente no Mercado Municipal da cidade. As amostras foram analisadas no laboratório de microbiologia do Instituto Federal do Norte de Minas Gerais (IFNMG) - Campus Salinas. Nas análises realizadas foi possível notar uma alta contagem de mesófilos e psicrotróficos, e baixa contagem de coliformes totais e termotolerantes, com três amostras fora dos padrões legais. Sugere -se ações de capacitação e regulamentação pelo poder público para melhorar a qualidade final do produto.(AU)
Subject(s)
Dairy Products/analysis , Dairy Products/microbiology , Cheese/analysis , Cheese/microbiology , Microbiological Techniques , Food HygieneABSTRACT
A qualidade da matéria prima é um dos maiores entraves ao desenvolvimento e consolidação da indústria de laticínios no Brasil pois , grande parte do leite produzido pelo país é oriunda de produtores rurais com baixa capacitação técnica e limitação financeira para os investimentos necessários. Diante do risco, é fundamental que as normativas estabelecidas sejam seguidas para garantir segurança ao consumidor final. Para tanto objetivou-se avaliar a qualidade microbiológica de quatro marcas distintas de leite pasteurizado tipo C, comercializado em Itabuna Bahia. Do material coletado foram feitas analises para a contagem de unidades formadoras de colônia por mililitro, coloração de Gram, e teste de coagulase e catalase. Os resultados mostraram presença de Staphylococcus spp. e enterobactérias nas marcas de leite pasteurizado selecionadas.(AU)