Clinic Unit of Infectious Diseases, Microbiology and Preventive Medicine, Institute of Biomedicine of Seville, University Hospital Virgen del Rocío/CSIC/University of Seville, Spain.
J Infect Dis. 2013 Nov 15;208(10):1561-70. doi: 10.1093/infdis/jit386. Epub 2013 Aug 1.
Outer membrane protein 33 (Omp33) is an outer membrane porin of Acinetobacter baumannii associated with carbapenem resistance. However, the role of Omp33 in the fitness and virulence of A. baumannii remains unknown. In the present study, we investigated the role of Omp33 in fitness and virulence of A. baumannii by using an isogenic knockout strain deficient in the omp33 gene (JPAB02), derived from the ATCC 17978 wild-type (wt). Both in vitro and in vivo defect in the growth rate was found in the JPAB02 strain in competition with the ATCC 17978 wt, highlighting the effect of Omp33 on the metabolic fitness. A significant reduction was observed both in adherence and invasion of human lung epithelial cells and in cytotoxicity of these cells and macrophages with JPAB02. In a murine peritoneal sepsis model, the JPAB02 strain exhibited lower lethal dose 0 (LD0), LD50, and LD100, and dissemination in mice, with reduced bacterial concentration in spleen and lungs. From these data, we concluded that Omp33 plays an important role for fitness and virulence of A. baumannii.
外膜蛋白 33（Omp33）是与碳青霉烯类耐药相关的鲍曼不动杆菌的外膜孔蛋白。然而，Omp33 在鲍曼不动杆菌的适应性和毒力中的作用尚不清楚。在本研究中，我们通过使用源自 ATCC 17978 野生型（wt）的同源敲除菌株 JPAB02（omp33 基因缺陷）来研究 Omp33 在鲍曼不动杆菌适应性和毒力中的作用。在与 ATCC 17978 wt 的竞争中，JPAB02 菌株在体外和体内的生长速度都存在缺陷，这突出了 Omp33 对代谢适应性的影响。与 JPAB02 相比，人肺上皮细胞的黏附和侵袭以及这些细胞和巨噬细胞的细胞毒性均显著降低。在小鼠腹腔脓毒症模型中，JPAB02 菌株的致死剂量 0（LD0）、LD50 和 LD100 均较低，在小鼠中的播散性也较低，脾和肺中的细菌浓度降低。从这些数据可以得出结论，Omp33 对鲍曼不动杆菌的适应性和毒力起着重要作用。
