INVITRO POSTANTIBIOTIC EFFECTS FOLLOWING MULTIPLE EXPOSURES OF CEFOTAXIME, CIPROFLOXACIN, AND GENTAMICIN AGAINST ESCHERICHIA-COLI IN POOLED HUMAN CEREBROSPINAL-FLUID AND MUELLER-HINTON BROTH

Multiple exposures with cefotaxime in either Mueller-Hinton broth or cerebrospinal fluid had no effect on killing or the duration of postantibiotic effect (PAE) in Escherichia coli strains tested. However, upon multiple exposures in Mueller-Hinton broth, ciprofloxacin and gentamicin PAEs significantly decreased with a concomitant reduction in bacterial killing. A reduction in bacterial killing following multiple ciprofloxacin and gentamicin exposures was also seen with cerebrospinal fluid; however, the PAE was maintained.