Bactericidal activity of tigemonam, alone and in combination with gentamicin

The in vitro bactericidal activity of tigemonam, alone and in combination with gentamicin, was evaluated against various strains of Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Salmonella enteritidis, Enterobacter cloacae, Proteus mirabilis, and Proteus vulgaris. Minimum inhibitory and bactericidal concentrations were determined on three consecutive days with an inoculum of 10(5) colony-forming units (CFU)/mL or a culture in the logarithmic growth phase. The results found tigemonam to be rapidly bactericidal against most Enterobacteriaceae isolated. In addition, the killing curves indicated a synergism between tigemonam and subinhibitory concentrations of gentamicin.