Tibo Luiz Henrique Soares, Bertol Jéssica Wildgrube, Bernedo-Navarro Robert Alvin, Yano Tomomasa
Department of Genetics, Evolution and Bioagents, Universidade Estadual de Campinas, Campinas, SP, Brazil.
Department of Genetics, Evolution and Bioagents, Universidade Estadual de Campinas, Campinas, SP, Brazil.
Braz J Infect Dis. 2016 May-Jun;20(3):298-302. doi: 10.1016/j.bjid.2016.01.003. Epub 2016 Mar 7.
Culture supernatant of sepsis-associated Escherichia coli (SEPEC) isolated from patients with sepsis caused loss of intercellular junctions and elongation of human umbilical vein endothelial cells (HUVEC). The cytotoxic factor was purified from culture supernatant of SEPEC 15 (serogroup O153) by liquid chromatography process. PAGE (polyacrylamide gel electrophoresis) showed that the purified SEPEC cytotoxic factor had a molecular mass of ∼150kDa and consisted of at least two subunits. At the concentration of 1 CD50 (40μg/mL) did facilitate transcytosis through the HUVEC cells monolayer of SEPEC 15 as much as E. coli K12 within 30min without affecting cell viability. These results suggest that this cytotoxic factor, named as SPF (SEPEC's permeabilizing factor), may be an important SEPEC virulence factor that facilitates bacterial access to the bloodstream.
从脓毒症患者中分离出的脓毒症相关大肠杆菌（SEPEC）的培养上清液导致人脐静脉内皮细胞（HUVEC）的细胞间连接丧失和细胞伸长。通过液相色谱法从SEPEC 15（血清群O153）的培养上清液中纯化细胞毒性因子。聚丙烯酰胺凝胶电泳（PAGE）显示，纯化的SEPEC细胞毒性因子分子量约为150kDa，由至少两个亚基组成。在1个半数细胞毒性剂量（CD50，40μg/mL）的浓度下，确实能够在30分钟内促进SEPEC 15与大肠杆菌K12一样多地通过HUVEC细胞单层进行转胞吞作用，且不影响细胞活力。这些结果表明，这种名为SPF（SEPEC的通透因子）的细胞毒性因子可能是促进细菌进入血流的重要SEPEC毒力因子。
