Abstract:
The cytotoxicity of cell-free culture filtrates of 31 isolates of Vibrio cholerae O1 and O139, 5 reference strains
and 26 clinical isolates, was tested on Madin Darby Bovine Kidney (MDBK) cells and Vero cells. The 3-[4,5-
dimethylthiazol-2-y]-2, 5-diphenyltetrazolium bromide (MTT) test was used to detect the effect of the filtrates
on the proliferation and viability of cultured cell populations. The filtrates were prepared from serial ten-fold
dilutions of inoculated AKI and APW broth media with and without the addition of polymyxin B. The APW
culture filtrates of both V. cholerae O1 and O139 with and without added polymyxin B showed greater toxicity
to MDBK cells as compared to AKI filtrates. The cytotoxicity of AKI-grown V. cholerae O139 to MDBK cells
was greater than that of V. cholerae O1 grown in the same medium. The cytotoxicity of APW filtrates on Vero
cells was low and only noted when polymyxin was added to the medium.
