Purpose: This study aimed to investigate the effect of compound CCG-203592 on human kidney (HK-2) and intestinal carcinoma (Caco-2) cells based on the influence of the compound on the expression of major virulence genes in E. coli O157:H7 strains.
Methods: According to our previous study, virulence gene expression in these strains was significantly decreased after a 6.5-h exposure to CCG-203592. HK-2 and Caco-2 cells were exposed to different concentrations of cell-free extracts or live cells following treatment of the cells with CCG-203592 or DMSO for 6.5 h. After a 3-day incubation, mammalian cell viability was measured by the MTT assay.
Results: Compared with the control, the relative viability of HK-2 cells exposed to the cell-free extract of strain C7927 pre-treated with CCG-203592 or DMSO, at all tested concentrations, was significantly decreased by 80% (P ≤ 0.03). The viability of HK-2 cells incubated with strain G5101, pre-treated with undiluted and 2× diluted CCG-203592 or DMSO, decreased by 40% (P ≤ 0.1). For the cell–free extract treatment, approximately 40% (P ≤ 0.1) of the HK-2 cell viability remained. No significant difference in HK-2 cell viability was seen for either bacterium treated with CCG-203592 and DMSO. No significant cytotoxicity was detected on Caco-2 cells at all concentrations for both strains.
Significance: It is possible that higher concentrations of CCG-203592 are needed to show effectiveness on the expression of the virulence genes. More studies are currently being conducted to further understand and investigate the effectiveness of the compound on E .coli O157:H7 virulence.