Health of Animals Laboratory, Agriculture Canada, 110 Stone Road West, Guelph, Ontario N1G 3W4, and Department of Veterinary Microbiology and Immunology, Ontario Veterinary College, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
Appl Environ Microbiol. 1993 Jun;59(6):1981-3. doi: 10.1128/aem.59.6.1981-1983.1993.
A neutral red assay involving Vero cells was used to quantitate the cytotoxic activity of verotoxins (VT) produced by Escherichia coli and to investigate changes in titer caused by altering the composition of the cell culture medium. Three variations on medium 199 were investigated: one involved supplementing the medium with 5% fetal bovine serum (FBS), a second was the use of serum-free (SF) medium that contained 5% bovine serum albumin and 5 mug of fibronectin per ml, and the third involved the use of 4% Ultroser G, a commercial serum replacement. The level of cytotoxicity varied markedly with the type of VT and with the medium that was used. For VT1, there was no difference in cytotoxicity between medium with 5% FBS and SF medium, but cytotoxicity was reduced more than 100-fold in medium containing Ultroser G compared with cytotoxicity in the other media. For VT2, VT2v, and VTe, there was a slight reduction in cytotoxicity in medium containing 4% Ultroser G and a more marked reduction in SF medium compared with cytotoxicity in medium containing 5% FBS.
采用包含 Vero 细胞的中性红分析来定量测定大肠杆菌产生的志贺样毒素（VT）的细胞毒性活性，并研究改变细胞培养基成分引起的效价变化。研究了三种 199 号培养基的变化：一种是在培养基中添加 5%胎牛血清（FBS），另一种是使用无血清（SF）培养基，该培养基含有 5%牛血清白蛋白和 5μg/ml 纤维连接蛋白，第三种是使用 4%Ultroser G，一种商业血清替代物。细胞毒性水平因 VT 的类型和使用的培养基而有很大差异。对于 VT1，含有 5%FBS 的培养基和 SF 培养基之间的细胞毒性没有差异，但与其他培养基相比，含有 Ultroser G 的培养基中的细胞毒性降低了 100 多倍。对于 VT2、VT2v 和 VTe，含有 4%Ultroser G 的培养基中的细胞毒性略有降低，而 SF 培养基中的细胞毒性比含有 5%FBS 的培养基中的细胞毒性降低更为明显。
