Mussi María A, Relling Verónica M, Limansky Adriana S, Viale Alejandro M
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.
FEBS Lett. 2007 Dec 11;581(29):5573-8. doi: 10.1016/j.febslet.2007.10.063. Epub 2007 Nov 13.
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.
我们之前将鲍曼不动杆菌中碳青霉烯耐药性的出现与一种名为CarO的外膜（OM）蛋白的缺失联系起来。发现CarO对L-鸟氨酸摄取至关重要：CarO缺陷菌株仅在L-鸟氨酸上生长时受到特异性损害，并且无法从培养基中摄取L-[（14）C]鸟氨酸。L-精氨酸以及程度较低的组氨酸和赖氨酸可有效竞争L-[（14）C]鸟氨酸的摄取。L-鸟氨酸还降低了鲍曼不动杆菌对亚胺培南的敏感性，这表明这两种化合物竞争摄取。总体结果表明，CarO参与鲍曼不动杆菌中L-鸟氨酸、碳青霉烯类药物和其他碱性氨基酸的选择性摄取。
