Search results for "LISTERIA MONOCYTOGENES"
showing 10 items of 142 documents
Growth potential of Listeria monocytogenes strains in mixed ready-to-eat salads
2009
In this study, a microbiological challenge test in three artificially contaminated retail mixed mayonnaise-based ready-to-eat salads stored at refrigerator temperatures (3°C and 7°C) for 48h was carried out. Shrimp-tomato salad, smoked ham salad and garlic cheese salad were separately contaminated by a suspension of particular Listeria monocytogenes strains. The number of L. monocytogenes, Enterobacteriaceae, staphylococci and total plate count (CFU/g) was determined. Listeria monocytogenes growth potential in the salads was calculated and evaluated. A significant increase in total plate count and L. monocytogenes count throughout storage of all three investigated salads was found. Enteroba…
Antilisterial peptides from Spanish dry-cured hams: Purification and identification.
2016
The typical Spanish dry-cured ham has a particular sensory quality that makes it a distinctive food, highly appreciated for consumers worldwide. Its particular physicochemical properties, such as high salt content and reduced water activity contribute to their shelf-stability. However, post-processing actions carried out for the commercialization of these products such as slicing may increase the risk of development of pathogenic microorganisms as Listeria monocytogenes. During ripening, muscle proteins are hydrolyzed by muscle peptidases releasing peptides and free amino acids. Some of these peptides have been described to exert biological activities such as antioxidant and ACE-inhibition.…
Survival of Listeria monocytogenes in Soil Requires AgrA-Mediated Regulation
2015
ABSTRACT In a recent paper, we demonstrated that inactivation of the Agr system affects the patterns of survival of Listeria monocytogenes (A.-L. Vivant, D. Garmyn, L. Gal, and P. Piveteau, Front Cell Infect Microbiol 4:160, http://dx.doi.org/10.3389/fcimb.2014.00160 ). In this study, we investigated whether the Agr-mediated response is triggered during adaptation in soil, and we compared survival patterns in a set of 10 soils. The fate of the parental strain L. monocytogenes L9 (a rifampin-resistant mutant of L. monocytogenes EGD-e) and that of a Δ agrA deletion mutant were compared in a collection of 10 soil microcosms. The Δ agrA mutant displayed significantly reduced survival in these b…
Survey of microbial quality of plant-based foods served in restaurants
2013
This study was carried out to evaluate the microbiological quality of plant-based foods obtained from foodservice establishments. The samples included cereals, legumes, fruits and vegetables. According to the European Commission Regulation (No. 2073/2005 and No. 1441/2007) and Spanish microbiological criteria (No. 3484/2000), vegetables were the plant-based dishes where more samples exceed the adopted limits of mesophilic aerobic counts and Enterobacteriaceae. Furthermore, Staphylococcus aureus and Escherichia coli were also found in several vegetable dishes. E. coli and Salmonella spp. were detected in 6.6% and 0.7% of lettuce samples, respectively. However, all the samples were negative f…
Antibacterial effects of enniatins J1 and J3 on pathogenic and lactic acid bacteria
2011
Abstract Enniatins (ENs) are N -methylated cyclohexadepsipeptides, secondary metabolites produced by various species of the genus Fusarium . They are known to act as antifungal, antiyeast and antibacterial and to possess antiinsecticidal and phytotoxic properties. In this study we evaluated for the first time the antibiotic effect of pure fractions of EN J 1 and J 3 on several pathogenic strains and lactic acid bacteria. The ENs J 1 and J 3 were purified from the fermentation extract of Fusarium solani growth on solid medium of wheat kamut, using the technique of the low pressure liquid chromatography (LPLC) followed by a semipreparative liquid chromatography (LC). The purity and the struct…
Assessment of Salmonella and Listeria monocytogenes level in ready-to-cook poultry meat: Effect of various high pressure treatments and potassium lac…
2014
International audience; The objective of this study was to develop a probabilistic model in order to determine the contamination level of Salmonella and Listeria monocytogenes in ready-to-cook poultry meat, after a high pressure (HP) treatment. The model included four steps: i) Reception of raw meat materials, mincing and mixing meat, ii) Partitioning and packaging into 200-g modified atmosphere packs, iii) High pressure treatment of the meat, and iv) Storage in chilled conditions until the end of the shelf-life. The model excluded the cooking step and consumption at consumer's home as cooking practices and heating times are highly variable. The initial contamination level of Salmonella and…
Quantification of Salmonella spp., Listeria monocytogenes and Escherichia coli O157:H7 in non-spiked food products and evaluation of real-time PCR as…
2011
Abstract Escherichia coli O157:H7, Listeria monocytogenes and Salmonella spp. are foodborne pathogens frequently associated with foods such as poultry, ready-to-eat products, fruits and vegetables. PCR-based procedures are rapid, sensitive and accurate; in particular, real-time PCR (qPCR), which besides being an automated high-throughput technique, allows quantification of foodborne pathogens. In the present work, qPCR-based methods were applied for the quantitative detection of E. coli O157:H7, Salmonella spp. and L. monocytogenes in a total of 306 non-spiked food samples in a study carried out in two laboratories simultaneously. qPCR allowed the detection of the three pathogens in around …
Microbial contamination of milk and dairy products from restaurants in Spain
2009
This study was carried out to evaluate the microbiological quality of milk and some dairy products, including 95 lots of warm milk, 95 lots of milk conserved at room temperature, and 75 lots of dairy products collected from restaurants in Spain. According to the European microbiological criteria (92/46/EEC, 93/43/EEC, and Commission Regulation No. 2073/2005), 31% and 35% of the total examined lots exceed the adopted limits of mesophilic aerobic counts and Enterobacteriaceae, respectively. This may be due to incorrect handling of milk and dairy products and inadequate cleaning and sanitization of milk container. Further, 2% of all the lots examined were positive for the presence of Escherich…
Effect of introduction of HACCP on the microbiological quality of some restaurant meals
2002
The microbial quality of Spanish potato omelette and pork loin before and after implementation of the HACCP system in University restaurants was used as indicator of food safety in this work. The prevalence of aerobic plate counts and incidences of Staphylococcus aureus, Escherichia coli, E. coli O157:H7, Listeria monocytogenes, Salmonella spp. and Clostridium perfringens were analysed. Results of implementation of the HACCP system show a lower incidence of studied microorganisms. On the other hand, a documented training in personal hygiene, good manufacturing practices (GMPs), cleaning and sanitation procedures and personal safety in addition to the rearrangement in the infrastructure of t…
Inhibition of foodborne pathogen bacteria by essential oils extracted from citrus fruits cultivated in Sicily
2012
Abstract The antagonistic activity of the essential oils (EOs) extracted by hydrodistillation from the fruit peel of several citrus genotypes (pummelo, grapefruit, orange, kumquat, mandarin and lemon) was evaluated against foodborne pathogen bacteria (43 strains of Listeria monocytogenes , 35 strains of Staphylococcus aureus and 14 strains of Salmonella enterica ). Five commercial EOs were used for comparison. Most of the EOs were more effective against the Gram-positive bacteria rather than Salmonella . EOs of lemon genotypes 14 and 15 showed the best results in terms of number of strains inhibited and width of the inhibition zone. The most susceptible strain of each species ( L. monocytog…