Isolation and Characterization of Bile Salts-Sensitive Mutants of Enterococcus faecalis

• DOI: 10.1007/s00284-002-3714-3
• Publication Date: 2002-11-06T14:02:50Z
• Authors: Yoann Le Breton; Alain Mazé; Axel Hartke; Sylviane Lemarinier; Yanick Auffray; Alain Rincé
• Keywords: 0301 basic medicine; 0303 health sciences; [SDV]Life Sciences [q-bio]; [SDV.BBM]Life Sciences [q-bio]/Biochemistry; [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology; [SDV.BBM.BM] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology; Molecular Biology/Molecular biology; Culture Media; [SDV] Life Sciences [q-bio]; Bile Acids and Salts; Mutagenesis, Insertional; 03 medical and health sciences; Bacterial Proteins; [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry; Mutation; [SDV.BBM] Life Sciences [q-bio]/Biochemistry, Molecular Biology; Enterococcus faecalis; Microscopy, Electron, Scanning; [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology; Molecular Biology

A library of insertional mutants of Enterococcus faecalis was constructed; it allowed the isolation and the characterization of 10 mutants affected in resistance to bile salts. Insertion loci of two mutants corresponded to genes of unknown function, while the amino acid sequences deduced from the other loci were homologous to proteins related to DNA repair, oxidative response, transcriptional regulation, dGTP hydrolysis, membrane composition, or cell wall synthesis. Further characterization of one mutant revealed that the insertion within the E. faecalis sagA gene led to a decrease of the resistance towards numerous independent physicochemical stresses, to modifications of the cell wall integrity, and to perturbations of cell division with septation anomalies.