at each of these time periods , serum bacteriostatic and bactericidal assays were performed against selected pathogens ( escherichia coli , serratia marcescens , enterobacter species ) with similar susceptibilities to ctx and ctz , but with varying sensitivity to des-ctx , and against one organism ( bacteroides fragilis ) toward which ctx and des-ctx exhibited synergistic activity .
C0450254
pathogens
C0029235
organism