Antibacterial activity of cefamandole in vitro.

Cefamandole, a new cephalosporin derivative, was found to have a broad spectrum of antimicrobial activity against a cross-section of both gram-positive and gram-negative bacteria isolated clinically. Gram-positive cocci, except for Streptococcus faecalis, were extremely susceptible to cefamandole; penicillin G-resistant Staphylococcus aureus also was highly susceptible. Minimal bactericidal concentrations for gram-positive cocci approximated the minimal inhibitory concentrations. Strains of Haemophilus influenzae were very susceptible to the drug. Most strains of Escherichia coli, Klebsiella species, and Proteus species were inhibited by low concentrations of cefamandole, Salmonella typhi, including ampicillin- and chloramphenicol-resistant strains, was inhibited by low concentrations of cefamandole. Susceptible bacteria became increasingly resistant as the inoculum size was increased. Strains of Pseudomonas were resistant to cefamandole.