Combination of High-Pressure Treatment at 500 MPa and Biopreservation with a Strain for Lowering the Bacterial Growth during Storage of Diced Cooked Ham with Reduced Nitrite Salt.

We investigated the combined effects of biopreservation and high-pressure treatment on bacterial communities of diced cooked ham prepared with diminished nitrite salt. First, bacterial communities of four commercial brands of diced cooked ham from local supermarkets were characterized and stored frozen. Second, sterile diced cooked ham, prepared with reduced levels of nitrite, was inoculated with two different microbiota collected from the aforementioned commercial samples together with a nisin-producing protective strain able to recover from a 500 MPa high-pressure treatment.

Quantification of Campylobacter jejuni gene expression after successive stresses mimicking poultry slaughtering steps.

Broiler meat is considered as the most important source of the foodborne pathogen Campylobacter jejuni. Exposure to stress conditions encountered during the slaughtering process may induce bacterial adaptation mechanisms, and enhance or decrease pathogen resistance to subsequent stress. This adaptation may result from changes in bacterial gene expression.

Comparison of Stomaching versus Rinsing for Recovering Bacterial Communities from Rainbow Trout (Oncorhynchus mykiss) Fillets.

Abstract: The use of high-throughput methods allows a better characterization of food-related bacterial communities. However, such methods require large amounts of high-quality bacterial DNA, which may be a challenge when dealing with a complex matrix that has a low concentration of bacteria, such as fresh fish fillets. Therefore, the choice of method used to recover bacteria from a food matrix in a cost-effective way is critical, yet little information is available on the performance of commonly used methods.

Influence of cell history on the subsequent inactivation of Campylobacter jejuni during cold storage under modified atmosphere.

Worldwide, Campylobacter infections are the main cause of human bacterial enteritis and broiler meat is considered as the most important source of human campylobacteriosis. Some mitigation strategies have been focused on reduction of Campylobacter at the slaughtering steps. This study aimed to determine the influence of consecutive stresses inspired by slaughtering steps on the subsequent inactivation of Campylobacter jejuni during cold storage under different modified atmospheres.

Genotypic and phenotypic characterization of the food spoilage bacterium Brochothrix thermosphacta.

Microbial food spoilage is responsible for significant economic losses. Brochothrix thermosphacta is one of the major bacteria involved in the spoilage of meat and seafood. Its growth and metabolic activities during food storage result in the production of metabolites associated with off-odors.

Selection procedure of bioprotective cultures for their combined use with High Pressure Processing to control spore-forming bacteria in cooked ham.

High Pressure Processing (HPP) and biopreservation can contribute to food safety by inactivation of bacterial contaminants. However these treatments are inefficient against bacterial endospores. Moreover, HPP can induce spore germination.

Two-dimensional fluorescence difference gel electrophoresis analysis of Listeria monocytogenes submitted to a redox shock.

The influence of redox alteration on the growth and proteomic pattern of Listeria monocytogenes was investigated. A redox shock was induced in cultures by addition of 3mM ferricyanide (FeCN) and 6mM dithiothreitol (DTT) to increase or to decrease respectively the redox potential naturally occurring at the beginning of growth. In both conditions, the reducing and oxidizing redox shock had a strong influence, decreasing the maximum growth rate by half compared to a control culture.

Antimicrobial activities of isothiocyanates against Campylobacter jejuni isolates.

Food-borne human infection with Campylobacter jejuni is a medical concern in both industrialized and developing countries. Efficient eradication of C. jejuni reservoirs within live animals and processed foods is limited by the development of antimicrobial resistances and by practical problems related to the use of conventional antibiotics in food processes.

Identification of lactobacilli residing in chicken ceca with antagonism against Campylobacter.

Bacteriocins produced by Lactobacillus salivarius have been recently recognized as a natural means to control Campylobacter and Salmonella in live poultry. This finding is of relevance since Campylobacter jejuni and Campylobacter coli are the predominant species isolated from poultry that are associated with human campylobacteriosis. In the present work, lactic acid bacteria (LAB) isolated from the cecum of twenty Tunisian chickens were identified and those isolates with antagonism against Campylobacter were further characterized.

Vagococcus penaei sp. nov., isolated from spoilage microbiota of cooked shrimp (Penaeus vannamei).

A polyphasic taxonomic study, using phenotypic, phylogenetic and genotypic characterization, was performed on five Gram-stain-positive, catalase-negative, coccus-shaped Vagococcus-like bacteria isolated from the spoilage microbiota of cooked shrimp. Comparative 16S rRNA gene sequence analysis indicated that the isolates belonged to the genus Vagococcus. The five isolates shared 100% 16S rRNA gene sequence similarity, and representative strain CD276(T) formed a branch that was distinct from the type strains of the six recognized species of the genus Vagococcus (Vagococcus fluvialis CCUG 32704(T), V.