title: CarO, an Acinetobacter baumannii outer membrane protein involved in carbapenem resistance, is essential for L-ornithine uptake.
abstract: We previously associated the emergence of carbapenem resistance in Acinetobacter baumannii with the loss of an outer membrane (OM) protein designated CarO. CarO was found essential for L-ornithine uptake: CarO-deficient strains were specifically impaired to grow only on L-ornithine, and failed to incorporate L-[(14)C] ornithine from the medium. L-arginine, and histidine and lysine to a lower extent, could effectively compete for L-[(14)C] ornithine uptake. L-ornithine also reduced A. baumannii sensitivity to imipenem, suggesting that both compounds compete for uptake. The overall results indicate that CarO participates in the selective uptake of L-ornithine, carbapenems, and other basic amino acids in A. baumannii.
authors.affiliation: Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET), Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, 2000, Rosario, Argentina.
authors.forename: María A
authors.initials: MA
authors.lastname: Mussi
authors.forename: Verónica M
authors.initials: VM
authors.lastname: Relling
authors.forename: Adriana S
authors.initials: AS
authors.lastname: Limansky
authors.forename: Alejandro M
authors.initials: AM
authors.lastname: Viale
mesh_terms: D040981:Acinetobacter baumannii / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D000900:Anti-Bacterial Agents / Q000378:metabolism / Q000494:pharmacology*; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport; D015780:Carbapenems / Q000378:metabolism / Q000494:pharmacology*; D002478:Cells, Cultured; D024881:Drug Resistance, Bacterial; D015378:Imipenem / Q000494:pharmacology; D009952:Ornithine / Q000378:metabolism*; D013696:Temperature; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D001425:Bacterial Outer Membrane Proteins; D015780:Carbapenems; D015378:Imipenem; D009952:Ornithine