Use of the collections of pathogenic bacteria from the Microbial Resource Centre CIRM-BP to evaluate the antibacterial potential of candidate molecules

International audienceThe International Centre for Microbial Resource dedicated to pathogenic bacteria (CIRM-BP) is located within the French National Institute for Agricultural Research (INRA) centre of Val de Loire. The activity of the CIRMBP is dedicated to the conservation and the distribution of strains of bacterial pathogens isolated from animals or from human as well as the distribution of their genomic DNAs. The CIRM-BP is ISO 9001 certified since 2008. Its collection comprises around 2500 strains belonging to 57 genera and 167 species of bacteria of risk groups 2 and 3. The CIRM-BP offers services related to strain identification, characterization and preservation. The CIRM-BP also develops scientific partnerships for studying biodiversity. Beside these activities, the CIRM-BP takes advantage of its collections of pathogenic strains to study the antibacterial potential of different molecules proposed by its collaborative partners. In that aim, a panel of pathogenic bacterial strains is first constituted considering the intended target for the candidate molecules (for example pathogenic bacteria specific of the production systems of farm animal). This leads to the choice of the bacterial species to be tested and of the strains, in function of their origin and context of isolation

Genome sequences of 17 Pasteurella multocida strains involved in cases of rabbit Pasteurellosis

International audienceThis article reports draft genome sequences of 17 Pasteurella multocida strains isolated from naturally infected rabbits. The total lengths of the assembled contigs ranged between 2.21 and 2.48 Mb, and the total number of genes detected on the contigs ranged between 2,088 and 2,416

Glutamate Dehydrogenase Activity Can Be Transmitted Naturally to Lactococcus lactis Strains To Stimulate Amino Acid Conversion to Aroma Compounds

Amino acid conversion to aroma compounds by Lactococcus lactis is limited by the low production of α-ketoglutarate that is necessary for the first step of conversion. Recently, glutamate dehydrogenase (GDH) activity that catalyzes the reversible glutamate deamination to α-ketoglutarate was detected in L. lactis strains isolated from a vegetal source, and the gene responsible for the activity in L. lactis NCDO1867 was identified and characterized. The gene is located on a 70-kb plasmid also encoding cadmium resistance. In this study, gdh gene inactivation and overexpression confirmed the direct impact of GDH activity of L. lactis on amino acid catabolism in a reaction medium at pH 5.5, the pH of cheese. By using cadmium resistance as a selectable marker, the plasmid carrying gdh was naturally transmitted to another L. lactis strain by a mating procedure. The transfer conferred to the host strain GDH activity and the ability to catabolize amino acids in the presence of glutamate in the reaction medium. However, the plasmid appeared unstable in a strain also containing the protease lactose plasmid pLP712, indicating an incompatibility between these two plasmids