0000000000133993
AUTHOR
Michel Hébraud
Biofilm formation of listeria monocytogenes strains under food processing environments and pan-genome-wide association study
International audience; Concerns about food contamination by Listeria monocytogenes are on the rise with increasing consumption of ready-to-eat foods. Biofilm production of L. monocytogenes is presumed to be one of the ways that confer its increased resistance and persistence in the food chain. In this study, a collection of isolates from foods and food processing environments (FPEs) representing persistent, prevalent, and rarely detected genotypes was evaluated for biofilm forming capacities including adhesion and sessile biomass production under diverse environmental conditions. The quantity of sessile biomass varied according to growth conditions, lineage, serotype as well as genotype bu…
Transcriptomic and proteomic responses of Microbacterium sp. C448 exposed to sulfamethazine antibiotic
International audience; The Microbacterium sp. C448 was isolated from a soil regularly exposed to sulfamethazine(SMZ), for its ability to partly mineralise this antibiotic and other related sulfonamides.The aim of our study was to explore its metabolic adaptation towards exposure to SMZenvironmental (10 mg/L) and medicinal (250 mg/L) concentrations. Its transcriptomic andproteomic responses were analysed by focusing on the degradation regulon (sad genes) andresistance genes (folP and sul1).The transcriptomic and proteomic results were essentially congruent whatever theconcentrations tested. In culture conditions, exposure to the highest concentration of SMZ led tothe highest sad expression …
Optimization of saliva sample preparation and analysis for identification of protein biomarkers
National audience
The cold shock response of the psychrotrophic bacterium Pseudomonas fragi involves four low-molecular-mass nucleic acid-binding proteins
The psychrotrophic bacterium Pseudomonas fragi was subjected to cold shocks from 30 or 20 to 5 degrees C. The downshifts were followed by a lag phase before growth resumed at a characteristic 5 degrees C growth rate. The analysis of protein patterns by two-dimentional gel electrophoresis revealed overexpression of 25 or 17 proteins and underexpression of 12 proteins following the 30- or 20-to-5 degrees C shift, respectively. The two downshifts shared similar variations of synthesis of 20 proteins. The kinetic analysis distinguished the induced proteins into cold shock proteins (Csps), which were rapidly but transiently overexpressed, and cold acclimation proteins (Caps), which were more or …
The main cold shock protein of Listeria monocytogenes belongs to the family of ferritin-like proteins
The transfer of the food-borne pathogen Listeria monocytogenes from 30 to 5 degrees C was characterized by the sharp induction of a low molecular mass protein. This major cold shock protein has an isoelectric point at pH 5.1 and a molecular mass of about 18 kDa, as observed on two-dimensional gel electrophoresis (2-DE) pattern. Its N-terminal sequence, obtained from the 2-DE spot, shared a complete sequence identity with a Listeria innocua non-heme iron-binding ferritin. The purification of these ferritin-like proteins (Flp) revealed a native molecular mass of about 100-110 kDa which indicates a polypeptide composed of six 18 kDa-subunits. Northern analysis indicated the presence of a 0.8-k…