Figure 6.

Bacterial drug resistance to cationic biocides. The minimum inhibitory concentrations (MICs) of chlorhexidine (CHX), cetylpyridinium chloride (CPC) and 12-methacryloyloxydodecyl-pyridinium bromide (MDPB) are plotted for (A) Enterococcus faecalis and (B) Streptococcus mutans. MIC determinations were repeatedly performed from passages of 0 to 10 (P0 to P10). MDPB and CPC caused no resistance for E. faecalis and S. mutans. However, repeated exposure of E. faecalis to CHX induced drug resistance. (Adapted from Kitagawa et al. 2016, with permission.)