Table I Growth response of Klebsiella pneumoniae to antibiotic treatment
TreatmentaClassMechanism Bacteri-TargetMIC (μg/ml)Lag (Ct, hr)Doubling time (min)Minitial (A260)Mdecay (A260)Growth decline (hr)
Untreated3.7121.400.861.3212
Ampicillin*PenicillincidalCell wall>1283.3721.790.871.2912
Cefazolin*CephalosporincidalCell wall44.2030.610.771.3914.2
MeropenemCarbapenemcidalCell wall115.1669.250.851.2511.1
Colistin*PolymyxincidalCell wall46.6525.650.851.3210.4
StreptomycinAminoglycosidecidal30S ribosome47.3431.840.991.136.5
DoxycyclineTetracyclineostatic30S ribosome16.3526.082.401.0014.8
Chloramphenicol*Amphenicolostatic50S ribosome1612.5879.240.931.148.5
  • aGrowth properties determined at the antibiotic MIC50.

  • *MIC indicates resistance (ampicillin) and reduced susceptibility (cefazolin, colistin, chloramphenicol).