AGAR WELL DIFFUSION ASSAY TESTING OF BACTERIAL SUSCEPTIBILITY TO VARIOUS ANTIMICROBIALS IN CONCENTRATIONS NONTOXIC FOR HUMAN-CELLS IN CULTURE

Previously, we showed that microbial susceptibility to antimicrobials in concentrations non-toxic for human cells in culture could be tested using the wet disc topical antimicrobial assay. In this report, wet d isc assay and agar well diffusion assay results were compared testing the susceptibility of Ps. aeruginosa isolates from burn patients to co ncentrations of Polymyxin B non-toxic for cultured cells. Both assays were performed on the same agar plates. No differences in results were observed. Further agar well diffusion assay testing showed that susce ptibility/resistance could be demonstrated when testing several antimi crobials in concentrations non-toxic for cultured cells against a vari ety of bacteria isolated from burn patients. Therefore, the more famil iar agar well diffusion as well as the wet disc assay can be used to t est microbial susceptibility to these concentrations of antimicrobials .