CarO, an Acinetobacter baumannii outer membrane protein involved in carbapenem resistance, is essential for L-ornithine uptake

MUSSI, A.; RELLING, V.; LIMANSKY A; VIALE, A.

FEBS LETTERS

Elsevier

Año: 2007 vol. 581 p. 5573 - 5578

0014-5793

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-[14C] ornithine from the medium. L-arginine, and histidine and lysine to a lower extent, could effectively compete for L-[14C] 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.