Search results for "MONOCYTOGENE"

Impact of relative air humidity fluctuations on the survival of Listeria monocytogenes : application to improve hygiene in food processing environment

2016

Environmental hydration fluctuations influence microorganism viability and activity. The air relative humidity (RH) is a potentially effective parameter to control the development and the persistence of pathogenic microorganisms. However, efficiency of this parameter remains not well characterized compared to others environmental factors such as pH or temperature. Drying is the final step of cleaning and disinfection processes used in the food industry. However, if this process is empirically used, it could also be used to improve the decontamination of surfaces in premises and reduce the persistence of microorganisms. Despite cleaning and disinfection, Listeria monocytogenes is commonly fo…

Ozona potenciālā izmantošana nerūsējošā tērauda virsmu dezinfekcijai gaļas pārstrādes uzņēmumos- dezinficējošo īpašību novērtējums laboratorijas apst…

2015

Bakalaura darbs tika izstrādās Pārtikas drošības, dzīvnieku veselības un vides zinātniskajā institūtā „BIOR”, Pārtikas un vides izmeklējumu laboratorijas Mikrobioloģijas nodaļā. Gaļas produktu un izstrādājumu ražošanas uzņēmumā “Grāvendāle” tika ņemti 15 virsmu nomazgājumu paraugi no dažādām ražošanas ceha virsmām, kas saskaras gan ar gatavo produkciju, gan ar izejvielām. Katrā paraugā tika noteikta Listeria, Enterobacteriacea, ZNGB, pienskābo baktēriju un Staphylococcus aureus klātbūtne. Tikai S.aureus klātbūtne netika noteikta nevienā paraugā. Pēc klātbūtnes noteikšanas tika identificēta katra mikroorganisma suga, attiecīgi tās bija- Listeria monocytogenes, Enterobacter cloacae, Klebisell…

L'influence de désinfectants sur L. monocytogenes en biofilm - Mise en évidence de Listeria spp. dans des aliments au Cambodge

2010

The impact of growth history and flagellation on the adhesion of variousListeria monocytogenesstrains to polystyrene

2009

International audience; The contribution of growth history and flagella to adhesion of Listeria monocytogenes was analysed. An in-frame deletion on the flagellin encoding gene (flaA) was performed in L. monocytogenes EGD-e to compare its adhesion ability with the parental strain, after cultivation at various pH values and temperatures. The pH, as well as the temperature, affected the adhesion of L. monocytogenes EGD-e. In addition, the adhesion of L. monocytogenes EGD-e was reduced in energy-depressed cells. Conversely, the physicochemical bacterial surface characteristics affected by growth history did not influence the adhesion. Adhesion variations observed among environmental and clinica…

Incidence and survival of human pathogens in French soils, impact of land use, pedoclimatic and biologic soil factors

2013

Soil contamination by bacterial pathogens can occur through manure, sewage sludge spreading or irrigation using waste water treatment plants effluents. Agricultural soils may act as reservoirs for these pathogens, play a significant role in their dissemination, leading to the potential contamination of food and water resources. Health risk associated with the occurrence of pathogens in environmental matrices has to be thoroughly evaluated. In this context, the objectives of this work were: i) to determine the prevalence of two pathogenic bacterial species (Listeria monocytogenes and Enterococcus faecalis) in a large collection of French soils originated from a systematic soil survey of the …

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…