Inoculum effect and bactericidal activity of cefditoren and other antibiotics against Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis.

The inoculum effect on minimum inhibitory and minimum bactericidal concentrations of cefditoren, benzylpenicillin, ampicillin, cefotaxime, ceftriaxone, and meropenem against six clinical isolates each of Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis was studied using inocula of approximately 10(4) to 10(5) and 10(7) to 10(8) cfu/ml. Vancomycin was also studied against Streptococcus pneumoniae. The inoculum effect was observed only with benzylpenicillin and ampicillin against five of six strains of Haemophilus influenzae. All antibiotics tested were bactericidal.