[Post-antibiotic effect of imipenem, amikacin and ciprofloxacin against various strains of Serratia marcescens].

The authors compared the post-antibiotic effect (PAE) of imipenem, amikacin, ciprofloxacin, and latamoxef against Serratia marcescens ATCC 13880 (type strain) and against 12 clinical strains belonging to Grimont's most frequent biotypes: A2a, A3a, A3b, A4a, A4b, A5, A6a, A8a, A8b, A8c, TT, TCT. PAE was determined by measuring bacterial growth kinetics after one hour exposure to concentration of 2 x MIC of 10(6) CFUs in Mueller-Hinton broth. Drug removal was by 10-3 dilution of the exposed culture. A PAE was consistently present with imipenem (range 0.8-2.9 hrs), amikacin (range 1.0-4.9 hrs), ciprofloxacin (range 1.4-2.8 hrs). The duration of PAE did not correlate with MIC or Grimont's biotypes.