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1.
Trop Anim Health Prod ; 54(4): 220, 2022 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-35764898

RESUMO

Smallholder farmers dominate the Kenyan dairy sector producing 95% of the total milk. However, several concerns have been raised on the quality and safety of the milk they produce. This study assessed the hygienic practices and microbial safety of milk supplied by smallholder farmers to processors in Bomet, Nyeri, and Nakuru counties in Kenya. Interviews and direct observations were carried out to assess hygiene and handling practices by farmers and a total of 92 milk samples were collected along four collection channels: direct suppliers, traders, cooperatives with coolers, and cooperatives without coolers. Microbial analysis was done following standard procedures and data analysed using GenStat and SPSS. This study revealed that farmers did not employ good hygienic practices in their routine dairy management. They used plastic containers for milking and milk storage (34.2%); they did not clean sheds (47.9%) and did not set aside cows that suffered from mastitis factors (83.6%), resulting in poor microbial quality of raw milk along the collection channels. The highest mean total viable counts (8.72 log10 cfu/ml) were recorded in Nakuru while Nyeri had the highest mean E. coli counts (4.97 log10 cfu/ml) and Bomet recorded the highest mean counts of 5.13 and 5.78 log10 cfu/ml for Staphylococcus aureus and Listeria monocytogenes respectively. Based on all above-mentioned parameters, the microbial load in most samples from all three counties exceeded the set Kenyan standards. Farmer training, improving road infrastructure, use of instant coolers at cooperatives, and quality-based payment systems are recommended as measures to curb microbial growth.


Assuntos
Indústria de Laticínios , Fazendeiros , Microbiologia de Alimentos , Higiene , Leite , Animais , Bovinos , Contagem de Colônia Microbiana/veterinária , Indústria de Laticínios/métodos , Indústria de Laticínios/normas , Fazendeiros/estatística & dados numéricos , Feminino , Manipulação de Alimentos/normas , Microbiologia de Alimentos/normas , Humanos , Higiene/normas , Quênia , Leite/microbiologia , Leite/normas
2.
BMC Microbiol ; 22(1): 34, 2022 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-35078415

RESUMO

BACKGROUND: As the increased consumption of ready-to-eat meat alternatives is a fairly recent trend, little is known about the composition and dynamics of the microbiota present on such products. Such information is nonetheless valuable in view of spoilage and food safety prevention. Even though refrigeration and modified-atmosphere-packaging (MAP) can extend the shelf-life period, microbial spoilage can still occur in these products. In the present study, the microbiota of a vegetarian alternative to poultry-based charcuterie was investigated during storage, contrasting the use of a culture-dependent method to a culture-independent metagenetic method. RESULTS: The former revealed that lactic acid bacteria (LAB) were the most abundant microbial group, specifically at the end of the shelf-life period, whereby Latilactobacillus sakei was the most abundant species. Metabarcoding analysis, in contrast, revealed that DNA of Xanthomonas was most prominently present, which likely was an artifact due to the presence of xanthan gum as an ingredient, followed by Streptococcus and Weissella. CONCLUSIONS: Taken together, these results indicated that Lb. sakei was likely the most prominent specific spoilage organisms (SSO) and, additionally, that the use of metagenetic analysis needs to be interpreted with care in this specific type of product. In order to improve the performance of metagenetics in food samples with a high DNA matrix but a low bacterial DNA load, selective depletion techniques for matrix DNA could be explored.


Assuntos
Bactérias/crescimento & desenvolvimento , Código de Barras de DNA Taxonômico/métodos , Código de Barras de DNA Taxonômico/normas , Microbiologia de Alimentos/métodos , Armazenamento de Alimentos/normas , Produtos da Carne/microbiologia , Vegetarianos , Atmosfera , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Contagem de Colônia Microbiana , Código de Barras de DNA Taxonômico/estatística & dados numéricos , Microbiologia de Alimentos/normas , Embalagem de Alimentos/métodos , Embalagem de Alimentos/normas , Armazenamento de Alimentos/métodos , Armazenamento de Alimentos/estatística & dados numéricos , Produtos da Carne/classificação , RNA Ribossômico 16S/genética , Refrigeração
3.
BMC Microbiol ; 21(1): 207, 2021 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-34238245

RESUMO

BACKGROUND: Microbial contamination of edible low moisture food poses a significant public health risk for human. In this study, the microbial quality of sweet dehulled sesame seed croquettes, salted dehulled sesame seed and the raw sesame seed, sold under ambient conditions were examined. The samples were collected in the cities of Burkina Faso. The first type is sweet dehulled sesame seed croquettes (n1 = 25); the second type is salted dehulled sesame seed (n2 = 25) and the third type is raw sesame seed (n3 = 25). Assessment of the microbial quality was based on the total aerobic mesophilic bacteria, the thermotolerant coliforms, the yeasts and moulds, the E. coli, and the Salmonella spp. using ISO methods. RESULTS: The results showed the presence of microorganisms varying from <1.0 to 1.72 × 105 CFU g- 1 for thermotolerant coliforms, from <1.0 to 6,12 × 106 CFU g- 1 for the total mesophilic aerobic flora and from <1.0 to 8.10 × 105 CFU g- 1 for yeasts and moulds. The higher contaminations rates were mostly observed in raw sesame seed samples. No E coli or Salmonella pathogens were detected. Based on international standards of dehydrated food, 50.67% of the ready to eat sesame are satisficing while 17.33% are acceptable and 32% are not satisficing. CONCLUSION: Attention should be emphasized on the processing practices, especially in crowded places where RTE sesames seeds are mostly sold. The high numbers of all microbial groups in these sesame seed samples suggested that the production of RTE sesame seed should be improved by better hygiene. This study highlights also that RTE sesame seed might harbor a wide range of microorganisms when processes are weak of hygiene.


Assuntos
Fenômenos Fisiológicos Bacterianos , Microbiologia de Alimentos/normas , Alimentos em Conserva/microbiologia , Fungos/fisiologia , Sesamum/microbiologia , Burkina Faso
5.
Foodborne Pathog Dis ; 18(5): 331-336, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33600236

RESUMO

In this study, we aimed to investigate the standard method used for quantification of norovirus in oysters in Japan for the provisional adaptation of the method as an alternative to ISO 15216-1:2017, to conduct a Japan baseline survey of norovirus in oysters. For this purpose, the method provided by the Japan Committee for Standardization of Virus Detection in Food was subjected to an interlaboratory study to determine the performance characteristics of the standard method used in Japan. As a result, the theoretical limit of quantification for norovirus GI and GII in oysters by the standard method used in Japan was expected to be 1.92 and 1.85 log10 copies/g, respectively. The repeatability standard deviations (Sr) were 0.26 and 0.30 log10 copies/g for GI and GII, respectively, and the reproducibility standard deviations (SR) were 0.47 and 0.44 log10 copies/g for GI and GII, respectively. Through the interlaboratory study, we specified several critical points to obtain scientifically reliable results by using the standard method used in Japan. Especially, necessity for application of using process control virus was the most crucial point that needed to be improved. In addition, there are many participating laboratories that could not handle dilution of standard and quantify or detect the viruses in the test samples. To ensure scientifically reliable test result, capacity building of laboratories and implementation of proficiency testing should be considered for future tasks in combination with an application of process control materials in the method. On the assumption that the problems revealed in this study will be solved, the standard method used in Japan would be suitable for use in Japan baseline survey of norovirus in oysters, which will contribute to the international action against norovirus in oysters, led by the EU.


Assuntos
Microbiologia de Alimentos/métodos , Norovirus/genética , Técnicas de Amplificação de Ácido Nucleico/métodos , Ostreidae/virologia , RNA Viral/isolamento & purificação , Animais , Microbiologia de Alimentos/normas , Japão , Técnicas de Amplificação de Ácido Nucleico/normas , Reprodutibilidade dos Testes , Inquéritos e Questionários
6.
Meat Sci ; 172: 108315, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32977291

RESUMO

A model describing Listeria innocua evolution according to process parameters of 51 Italian salami processes and HPP in 31 companies was developed. A total of 51 challenge tests were performed. During processing a L. innocua reduction of 0.34-4.32 Log10 CFU/g was observed and HPP further reduced the count of 0.48-3.47 Log10 CFU/g; an overall reduction of 1.04-5.68 is reached. PH after acidification/drying process, aw after seasoning, duration of the seasoning and caliber resulted associated (p < 0.05) with L. innocua decrease. HPP efficacy was associated (p < 0.05) with aw and pH of the product: higher the pH and aw after the acidification/drying and seasoning phases, higher resulted the L. innocua reduction after HPP. No significant association was observed between L.innocua and salt, nitrate and starter content and other characteristics of process. The model meets companies and Authorities needs and represents a useful tool to predict L. monocytogenes lethality, giving recommendations to food business operators interested in exportation to the U.S.


Assuntos
Manipulação de Alimentos/métodos , Listeria/fisiologia , Produtos da Carne/microbiologia , Animais , Contagem de Colônia Microbiana , Dessecação , Fermentação , Microbiologia de Alimentos/normas , Concentração de Íons de Hidrogênio , Itália , Produtos da Carne/normas , Suínos , Estados Unidos
7.
Int J Food Microbiol ; 336: 108916, 2021 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-33091756

RESUMO

Predictive modelling is used in microbiological risk assessment to quantify the growth and inactivation of microorganisms through the use of mathematical models. Campylobacter jejuni is one of the main foodborne pathogens and broiler meat is considered as the most important source of human campylobacteriosis. The purpose of this study was to assess the effects of heating and chilling during the poultry slaughter process on inactivation kinetics of Campylobacter jejuni during chilled storage in order to predict its contamination level prior to preparation and consumption in the consumer's home, and then to assess the compliance to a Performance Objective (PO). Three strains of C. jejuni were submitted to consecutive heat (54 °C for 3 min) and cold (3 °C for 2 h) stresses, mimicking the two main slaughtering steps, i.e. scalding and chilling, by inoculating chicken fillets with three different concentrations (4, 6 and 8 log10 CFU/g). Fillets were then stored at 6 °C during 17 days under the modified atmosphere currently used by food processors (70% O2/30% CO2). For all strains, bacterial log reduction was the lowest when inoculated at 8 log10 CFU/g. One strain showed an enhanced resistance during cold storage after application of stressing steps, suggesting an impact of the cell history on further bacterial resistance. Taking strain variability into account, after six days of storage, predictions showed compliance of ready-to-be-cooked chicken meat with a hypothetical PO of 2.55 log10 CFU/g, value set before the meat enters the consumer's home by the ICMSF (International Commission on Microbiological Specifications for Foods). This study opens the path to assess the compliance to a PO of Campylobacter jejuni in poultry meat and more generally provides inputs to refine microbiological risk assessment by taking into account the cell history and more particularly the impact of stressful steps on the subsequent inactivation at consumer's home.


Assuntos
Campylobacter jejuni/fisiologia , Microbiologia de Alimentos/normas , Carne/microbiologia , Modelos Teóricos , Aves Domésticas/microbiologia , Animais , Galinhas/microbiologia , França
8.
Int J Food Microbiol ; 337: 108955, 2021 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-33186831

RESUMO

Probabilistic topic modelling is frequently used in machine learning and statistical analysis for extracting latent information from complex datasets. Despite being closely associated with natural language processing and text mining, these methods possess several properties that make them particularly attractive in metabolomics applications where the applicability of traditional multivariate statistics tends to be limited. The aim of the study was thus to introduce probabilistic topic modelling - more specifically, Latent Dirichlet Allocation (LDA) - in a novel experimental context: volatilome-based (sea) food spoilage characterization. This was realized as a case study, focusing on modelling the spoilage of Atlantic salmon (Salmo salar) at 4 °C under different gaseous atmospheres (% CO2/O2/N2): 0/0/100 (A), air (B), 60/0/40 (C) or 60/40/0 (D). First, an exploratory analysis was performed to optimize the model tunings and to consequently model salmon spoilage under 100% N2 (A). Based on the obtained results, a systematic spoilage characterization protocol was established and used for identifying potential volatile spoilage indicators under all tested storage conditions. In conclusion, LDA could be used for extracting sets of underlying VOC profiles and identifying those signifying salmon spoilage, giving rise to an extensive discussion regarding the key points associated with model tuning and/or spoilage analysis. The identified compounds were well in accordance with a previously established approach based on partial least squares regression analysis (PLS). Overall, the outcomes of the study not only reflect the promising potential of LDA in spoilage characterization, but also provide several new insights into the development of data-driven methods for food quality analysis.


Assuntos
Microbiologia de Alimentos/métodos , Modelos Estatísticos , Salmo salar/microbiologia , Alimentos Marinhos/microbiologia , Animais , Microbiologia de Alimentos/normas , Qualidade dos Alimentos , Armazenamento de Alimentos , Gases/análise , Metabolômica , Compostos Orgânicos Voláteis/análise
9.
Poult Sci ; 100(1): 263-272, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33357690

RESUMO

The aim of the research was to estimate the effect of selected lactic acid bacterial strains on the technological quality and microbiological stability of mechanically separated poultry meat (MSPM) cured with a reduced amount of sodium nitrite. The 5 different treatments of MSPM batters were prepared: C150 - control cured with sodium nitrite at 150 mg/kg, C50 - control cured with sodium nitrite at 50 mg/kg, PL1 - cured with sodium nitrite at 50 mg/kg and inoculated Lactobacillus plantarum SCH1 at about 107 cfu/g, PL2 - cured with sodium nitrite at 50 mg/kg and inoculated Lactobacillus brevis KL5 at about 107 cfu/g, and PL3 - cured sodium nitrite at 50 mg/kg and inoculated L. plantarum S21 at about 107 cfu/g. The MSPM batters were tested at 1, 4 and 7 d of being in refrigerated storage. The scope of the research was as follows - physicochemical determinations: pH and redox, nitrates and nitrites as well as nitrosyl pigments levels, color estimation with a Comission Internationale de l'Eclairage Lab system and microbiological determinations: the total viable counts, the mesophilic lactic acid bacteria counts, Escherichia coli and Enterobacteriaceae counts. The inhibitory effect of L. plantarum SCH1 isolated from the ecological raw fermented meat product on E. coli in cured MSPM batters during refrigerated storage was proved (P < 0.05). The use of lactic acid bacterial strains in cured batters that were prepared and based on mechanically separated poultry meat did not have a negative effect on their technological quality. The positive effect of L. brevis KL5 on the level of nitrosyl pigments in the cured MSPM batters was observed (P < 0.05). The conducted research suggested the possibility of using the selected bacterial strains of the Lactobacillus genus to improve the microbiological quality of MSPM cured with a reduced amount of sodium nitrite.


Assuntos
Antibiose , Fenômenos Fisiológicos Bacterianos , Microbiologia de Alimentos , Lactobacillales , Produtos da Carne , Nitrito de Sódio , Animais , Bactérias/efeitos dos fármacos , Carga Bacteriana , Enterobacteriaceae/efeitos dos fármacos , Enterobacteriaceae/fisiologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/fisiologia , Microbiologia de Alimentos/normas , Ácido Láctico , Lactobacillales/fisiologia , Produtos da Carne/análise , Produtos da Carne/microbiologia , Produtos da Carne/normas , Aves Domésticas , Nitrito de Sódio/farmacologia
10.
Molecules ; 25(23)2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-33271777

RESUMO

This study was performed in order to assess technological characteristics, proximate composition, fatty acids profile, and microbiological safety of sous-vide processed salmon in comparison with steaming and roasting. The cooking loss was lower in the sous-vide method (6.3-9.1%) than in conventional methods (11.6-16.2%). The preparation of salmon using sous-vide was more time- and energy-consuming than steaming. The dry matter content of the salmon fillets was higher in conventionally processed samples than sous-vide due to the evaporation of water, and it was connected with total protein (r = 0.85) and lipid content (r = 0.73). Analysis of the fatty acids profile only revealed significant differences in six fatty acids. All of the heat treatment methods ensured microbiological safety with regard to coagulase-positive Staphylococcus, E. coli, Listeria monocytogenes, and Salmonella spp. However, in sous-vide (57 °C, 20 min) and steamed samples after storage Enterobacteriaceae bacteria (<104) was detected. Summing up, high parameters of sous-vide salmon cooking, when considering both technological parameters, nutritional value, and microbiological status should be recommended.


Assuntos
Bactérias/crescimento & desenvolvimento , Culinária/normas , Microbiologia de Alimentos/normas , Valor Nutritivo , Salmo salar/microbiologia , Alimentos Marinhos/análise , Animais , Culinária/métodos , Alimentos Marinhos/microbiologia
11.
Compr Rev Food Sci Food Saf ; 19(2): 703-732, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-33325184

RESUMO

Ready-to-eat foods (RTEs) are foods consumed without any further processing. They are widely consumed as choice meals especially by school-aged children and the fast-paced working class in most low- and middle-income countries (LMICs), where they contribute substantially to the dietary intake. Depending on the type of processing and packaging material, RTEs could be industrially or traditionally processed. Typically, RTE vendors are of low literacy level, as such, they lack knowledge about good hygiene and food handling practices. In addition, RTEs are often vended in outdoor environments such that they are exposed to several contaminants of microbial origin. Depending on the quantity and type of food contaminant, consumption of contaminated RTEs may result in foodborne diseases and several other adverse health effects in humans. This could constitute major hurdles to growth and development in LMICs. Therefore, this review focuses on providing comprehensive and recent occurrence and impact data on the frequently encountered contaminants of microbial origin published in LMICs within the last decade (2009 to 2018). We have also suggested viable food safety solutions for preventing and controlling the food contamination and promoting consumer health.


Assuntos
Fast Foods/microbiologia , Microbiologia de Alimentos/métodos , Países em Desenvolvimento , Contaminação de Alimentos/análise , Manipulação de Alimentos/métodos , Microbiologia de Alimentos/normas , Inocuidade dos Alimentos/métodos , Doenças Transmitidas por Alimentos/microbiologia , Humanos
12.
J Dairy Sci ; 103(11): 9758-9773, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33076187

RESUMO

Dairy production plays an important role in the lives of many people in Rwanda and Nepal. The aim of the Feed the Future Innovation Lab for Livestock Systems (LSIL; Gainesville, FL) is to introduce new location-appropriate technologies and to improve management practices, skills, knowledge, capacity, and access to inputs across livestock value chains in developing countries such as Rwanda and Nepal. To assist LSIL, our first aim was to describe gaps in the management of cows and in milk processing that constrain milk quality and quantity in Rwanda and Nepal. Our second aim was to describe training-of-trainers workshops in both countries as an initial response to the findings from the first objective. We conducted literature reviews and did rapid needs assessments in both countries. The literature reviews revealed similar aspects of the challenges of smallholder crop-livestock mixed farming systems in both countries. Many farms are struggling with feed quality, reproduction, and health of dairy cows. Milk production per cow and quality is often low. Fresh milk is collected by milk collection and cooling centers. Hygiene and milk processing capability and shelf life of products can be improved. Local rapid needs assessments were conducted in 2016 (Rwanda) and 2017 (Nepal) through visits to farms, milk collection and chilling centers, and processing plants, and through discussions with local dairy officials. The assessments supplemented and completed our understanding of stakeholders' needs in management and processing of milk. Limiting factors to improving the productivity, quality, and safety of milk in Rwanda and Nepal were a combination of sometimes limited knowledge in areas such as feeding, mastitis control, and hygiene, and a lack of access to resources such as quality feeds, transportation, and cooling that hindered implementation of existing knowledge. Training-of-trainers workshops in milk processing and hygiene were developed and given in Rwanda and Nepal based on the rapid needs assessments, and these were well received. We concluded that Rwanda and Nepal both have smallholder dairy farms that often face similar challenges such as lack of quality feeds, needs for basic dairy management education, low cattle productivity, and undesirable milk quality. Training-of-trainers programs to address these basic issues may be successful. Continued improvements in the dairy value chain depend on available resources for education.


Assuntos
Indústria de Laticínios/normas , Microbiologia de Alimentos/normas , Leite/microbiologia , Animais , Bovinos , Feminino , Nepal , Ruanda
14.
Food Microbiol ; 91: 103535, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32539946

RESUMO

Farmed insects can offer an environmentally sustainable aquafeed or livestock feed ingredient. The value of black soldier fly (Hermetia illucens) (BSF) larvae could be improved by enrichment in omega-3 through the dietary inclusion of seaweed. However, the industry practice of drying seaweed at low temperatures to retain nutritional properties may benefit the survival of human pathogenic bacteria, particularly if the seaweed has been harvested from contaminated water. Here we have demonstrated that E. coli and E. coli O157:H7 died-off in seaweed dried at 50 °C, although both were detected in the dried powder following 72 h storage. V. parahaemolyticus fell below the level of detection in stored seaweed after drying at ≥ 50 °C, but L. monocytogenes remained detectable, and continued to grow in seaweed dried at ≤60 °C. Therefore, drying seaweed at low temperatures risks pathogen carry-over into insects destined for animal feed. BSF larvae reared on an artificially contaminated seaweed-supplemented diet also became contaminated by all four bacteria present in the supplement. Water quality at seaweed harvesting sites, seaweed desiccation, and insect rearing practices, represent critical points where development of regulatory standards could achieve targeted control of pathogenic hazards.


Assuntos
Ração Animal/microbiologia , Bactérias/isolamento & purificação , Dípteros/microbiologia , Alga Marinha/microbiologia , Ração Animal/normas , Animais , Bactérias/classificação , Bactérias/patogenicidade , Suplementos Nutricionais/microbiologia , Suplementos Nutricionais/normas , Dípteros/crescimento & desenvolvimento , Manipulação de Alimentos/métodos , Microbiologia de Alimentos/normas , Inocuidade dos Alimentos , Humanos , Larva/crescimento & desenvolvimento , Larva/microbiologia , Temperatura
15.
Food Microbiol ; 91: 103532, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32539959

RESUMO

Poland is one of the largest food producers in Europe, and the West Pomeranian region of Poland is a large producer of RTE food. Thus, the objective of this study was to determine the prevalence of Listeria sp. and L. monocytogenes (LM) in RTE foods manufactured by 13 selected Polish food producers whose processing plants are located in this region. In total, 650 samples of RTE foods, and 263 ingredients of salads and desserts were analyzed. Almost 18% of the RTE foods failed to meet the zero tolerance limit for Listeria, which means they should not be allowed for retail. LM was isolated from 13.5% of the samples, with counts of 10-100 CFU/g noted in half of them. Products with meat and dairy ingredients, and fish products, sandwiches, sprouts and sushi, were at the highest statistically significant risk of LM contamination. Four serogroups were identified among the LM isolated from RTE foods, of which the 4b-4d-4e serogroup was predominating. The samples most heavily contaminated with LM contained even 2 serogroups. Results were subjected to the cluster analysis and principal component analysis to determine correlations between food groups, food ingredients, producers, contamination level, and serogroups of LM.


Assuntos
Contaminação de Alimentos/análise , Microbiologia de Alimentos/estatística & dados numéricos , Listeria/isolamento & purificação , Contagem de Colônia Microbiana , Qualidade de Produtos para o Consumidor , Manipulação de Alimentos/estatística & dados numéricos , Microbiologia de Alimentos/normas , Listeria/classificação , Listeria/genética , Listeria monocytogenes/isolamento & purificação , Polônia/epidemiologia , Prevalência , Sorogrupo
16.
PLoS One ; 15(6): e0233853, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32502212

RESUMO

Rapid detection of bacterial pathogens is a critical unmet need for both food and environmental samples such as irrigation water. As a part of the Food safety Modernization Act (FSMA), The Produce Safety rule has established several requirements for testing for the presence of generic Escherichia coli in water, but the current method available for testing (EPA M1603) demands specified multiple colony verification and highly trained personnel to perform these tests. The purpose of the study was to assess a phage induced bacterial lysis using quantitative image analysis to achieve rapid detection of E. coli at low concentrations within 8 hours. This study aimed to develop a simple yet highly sensitive and specific approach to detect target bacteria in complex matrices. In the study, E. coli cells were first enriched in tryptic soy broth (TSB), followed by T7 phage induced lysis, concentration, staining and fluorescent imaging. Image analysis was conducted including image pre-processing, image segmentation and quantitatively analysis of cellular morphological features (area, eccentricity and full width at half maximum). Challenge experiments using realistic matrices, including simulated fresh produce wash water, coconut water and spinach wash water, demonstrated the method can be applied for use in situations that occur in food processing facilities. The results indicated E. coli cells that are lysed by T7 phages demonstrated significantly (P < 0.05) higher extracellular DNA release, altered cellular shape (from rod to circular) and diffused fluorescent signal intensity. Using this biosensing strategy, a sensitivity to detect Escherichia coli at 10 CFU/ml within 8 hours was achieved, both in laboratory medium and in complex matrices. The proposed phage based biosensing strategy enables rapid detection of bacteria and is applicable to analysis of food systems. Furthermore, the steps involved in this assay can be automated to enable detection of target bacteria in food facilities without extensive resources.


Assuntos
Bacteriófago T7 , Técnicas Biossensoriais/métodos , DNA Ambiental/isolamento & purificação , Escherichia coli/isolamento & purificação , Processamento de Imagem Assistida por Computador , DNA Bacteriano/isolamento & purificação , Escherichia coli/genética , Escherichia coli/virologia , Microbiologia de Alimentos/normas , Inocuidade dos Alimentos , Microbiologia da Água/normas
17.
An Real Acad Farm ; 86(2): 117-124, abr.-jun. 2020. graf, ilus, tab
Artigo em Espanhol | IBECS | ID: ibc-193547

RESUMO

Uno de los quesos frescos tradicionales típicos del Ecuador es el queso de hoja, un queso de pasta hilada, que se elabora de manera artesanal envuelto en hoja de achira (Canna indica), mientras en la industria es empacado al vacío en bolsas de polietileno. En el presente estudio se comparó la calidad microbiológica de estos quesos, evaluando los indicadores de la calidad higiénico-sanitaria, además se cuantificaron y caracterizaron fenotípicamente bacterias ácido lácticas (BAL). Las muestras se recolectaron en queseras artesanales y plantas industriales de la ciudad de Latacunga. Se determinaron recuentos de aerobios mesófilos aplicando la Norma Técnica Ecuatoriana NTE INEN 1529 5, coliformes totales, Escherichia coli y Staphylococcus aureus se analizaron utilizando placas Petrifilm (AOAC 991.14 - AOAC 2003.07). El recuento de bacterias ácido lácticas empleó el método PRT-712.02-047. Los resultados de los indicadores de la calidad higiénico-sanitaria: coliformes, E. coli y S. aureus examinados en los quesos de hoja artesanales y de elaboración industrial, en todos los casos superaron los límites de aceptabilidad establecidos por la normativa ecuatoriana, sugiriendo deficiente calidad higiénica de los procesos o incorrecta manipulación de la leche empleada como materia prima. Los recuentos de Lactobacillus y Lactococcus en los quesos industriales presentaron una reducción estadísticamente significativa comparados con los recuentos de estos microorganismos en los quesos artesanales, esto corresponde a una diferencia en porcentaje de 18,15 % y 14,27 % respectivamente. Se aisló un total de 32 cepas de bacterias de ácido láctico, estas mostraron características fenotípicas similares, pero tuvieron una respuesta diferente a la tolerancia a niveles de pH (4.4; 9.4) y NaCl (6.5 %). Es importante complementar la evaluación microbiológica con un análisis sensorial para evaluar el efecto de las BAL sobre las características organolépticas de los quesos de hoja de procedencia artesanal e industrial


One of the traditional fresh cheeses in Ecuador is the artisanal leafcheese, a kind of stretched-curd cheese. The artisanal product is wrapped in achira leaves (Canna indica), while the industrial leafcheese is packed at vacuum in high density polyethylene bags. In this study the microbiological quality of both products was compared. The hygienic-sanitary microbial indicators and lactic acid bacteria (LAB) were quantified. The LAB isolated were characterized phenotypically. The samples were obtained from artisanal cheese-making and industrial located in Latacunga city province Cotopaxi. The total aerobic mesophilic count was made based on national regulations (NTE INEN 1529 5); total coliforms, Escherichia coli and Staphylococcus aureus was evaluated using petrifilm methods (AOAC 991.14 - AOAC 2003.07) and to LAB was used PRT-712.02-047. The results show high quantities of total coliforms, E. coli and S. aureus in both products, these data exceed the limits of acceptability established in Ecuadorian regulations, this evidence poor hygienic quality of the processes or incorrect controls of milk as raw material. The lactic acid bacteria count showed statistically significant differences, the industrial cheeses had a reduction of 18,15% of Lactobacillus and 14,27% of Lactococcus compared with artisanal cheeses. A total of 32 strains of lactic acid bacteria were isolated, these showed similar phenotypic characteristics, but these had a different response at the level of pH (4,4;9,4) and NaCl (6,5%). The sensory evaluation will be an important complement in this type of study


Assuntos
Queijo/microbiologia , Microbiologia de Alimentos/normas , Coliformes , Escherichia coli/isolamento & purificação , Staphylococcus aureus/isolamento & purificação , Carga Bacteriana , Equador , Queijo/normas , Escherichia coli/genética , Staphylococcus aureus/genética , Fenótipo
18.
Epidemiol Infect ; 148: e135, 2020 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-32406346

RESUMO

The aim of this study was to review microbiology results from testing >2500 raw drinking milk and dairy products made with unpasteurised milk examined in England between 2013 and 2019. Samples were collected as part of incidents of contamination, investigation of infections or as part of routine monitoring and were tested using standard methods for a range of both pathogens and hygiene indicators. Results from testing samples of raw cow's milk or cheese made from unpasteurised milk for routine monitoring purposes were overall of better microbiological quality than those collected during incident or investigations of infections. Results from routine monitoring were satisfactory for 62% of milks, 82% of cream, 100% of ice-cream, 51% of butter, 63% of kefir and 79% of cheeses, with 5% of all samples being considered potentially hazardous. Analysis of data from cheese demonstrated a significant association between increasing levels of indicator Escherichia coli with elevated levels of coagulase positive staphylococci and decreased probability of isolation of Shiga toxin-producing E. coli. These data highlight the public health risk associated with these products and provide further justification for controls applied to raw drinking milk and dairy products made with unpasteurised milk.


Assuntos
Bactérias/isolamento & purificação , Laticínios/microbiologia , Laticínios/normas , Microbiologia de Alimentos/normas , Animais , Bovinos , Inglaterra , Pasteurização
19.
Vopr Pitan ; 89(2): 64-76, 2020.
Artigo em Russo | MEDLINE | ID: mdl-32459906

RESUMO

In order to increase the efficiency of food production, micro-organisms are used whose genetic material has been modified by directed mutagenesis or by transgenesis. Such products belong to a new type of products, the mandatory condition for the use of which is to confirm its safety when used in food. The aim of the article - justification of the need to improve the system for assessing the safety of foods obtained by microbial synthesis. Material and methods. The analysis and generalization of current scientific researches published in the databases Scopus, Web of Science, PubMed, RSCI, as well as national and international regulatory and legislative documents have been carried out. Results and discussion. The analysis of scientific data, legislative and regulatory documents of international legislation, the European Union, as well as other economically developed countries, has shown that a mandatory element of assessing the possibility of safe use of food produced by microbial synthesis is the study of the sequence of transgenic insert nucleotides in the producer strain in order to analyze the presence of pathogenicity determinants, antibiotic resistance, and the ability to produce toxic metabolites. The data obtained in vitro on the absence of risks of using both producer strains and the enzyme preparations and other ingredients synthesized by them in the food industry should be confirmed in experiments in vivo. Currently, the need to comply with these requirements, as well as the main criteria for assessing the risks of such food, are mainly provided by legislation and regulations of the Russian Federation. At the same time, the system of sanitary and hygienic assessment of the safety of producer strains and food ingredients produced by them needs to be updated.


Assuntos
Manipulação de Alimentos , Microbiologia de Alimentos , Inocuidade dos Alimentos , Legislação sobre Alimentos , União Europeia , Manipulação de Alimentos/legislação & jurisprudência , Manipulação de Alimentos/normas , Microbiologia de Alimentos/legislação & jurisprudência , Microbiologia de Alimentos/normas , Humanos , Medição de Risco , Federação Russa
20.
Int J Food Microbiol ; 322: 108564, 2020 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-32163798

RESUMO

Campylobacter is one of the most important causative agents of foodborne illnesses worldwide. The poultry reservoir is the main source of Campylobacter. Within the broiler production chain, campylobacters can only multiply in the chicken's intestinal tract. Intervention at farm level to reduce Campylobacter is thus preferred, but despite extensive study, no highly effective solutions have been found to combat Campylobacter at farm level. Slaughterhouses are experiencing great pressure to deliver carcasses with low Campylobacter contamination even when they receive and slaughter Campylobacter colonized flocks. Since 2018, a process hygiene criterion (EU 2017/1495) with the critical limit of <1000 cfu/g neck skin has been implemented in EU Member States based on the calculation done at the time of the study that human campylobacteriosis cases could be halved if all carcasses would comply with a criterion of <1000 cfu/g neck skin. This review covers Campylobacter contamination of broiler carcasses from transport through the different slaughter steps. Possible intervention methods during slaughter are discussed with a focus on the European situation, where chemicals are not allowed to disinfect carcasses.


Assuntos
Matadouros/normas , Campylobacter/isolamento & purificação , Manipulação de Alimentos/normas , Microbiologia de Alimentos/normas , Aves Domésticas/microbiologia , Animais , Galinhas , Europa (Continente)/epidemiologia , Contaminação de Alimentos/análise , Contaminação de Alimentos/prevenção & controle , Manipulação de Alimentos/métodos , Microbiologia de Alimentos/métodos , Higiene/normas
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