Kill kinetics of the cephalosporin antibiotics cephalexin and cefuroxime against bacteria of veterinary importance.

Kill kinetic studies for two cephalosporin antibiotics, cephalexin and cefuroxime were carried out against veterinary strains of Escherichia coli, Pasteurella multocida, Streptococcus suis, Erysipelothrix rhusiopathiae and a laboratory culture of Staphylococcus aureus. In more than 90 per cent of cases a kill of more than 99 per cent was achieved within four hours of antibiotic treatment at concentrations of 2 or 4 micrograms/ml. Although cefuroxime was effective at lower concentrations than cephalexin the rates of kill of the two antibiotics were comparable. The results are discussed in relation to in vivo dosage regimens.