Fecal sample from mouse number 40 treated with streptomycin for 28 days and colonized with an E. coli _lsrKluxS strain for 26 days 
Study the impact of the quorum sensing signal AI2 on the microbiota composition. Mice treated with streptomycin were given by oral gavage 3 different strains of E.coli with different capabilities to produce or uptake AI2. Fecal samples were analyzed 28 days after streptomycin treatment started.