In vitro activity of cefixime, a new oral cephalosporin.

The in vitro activities of cefixime and seven comparative oral antimicrobials were studied. MIC90S of cefixime were 0.015-1 micrograms/ml for Haemophilus influenzae, Branhamella catarrhalis, Escherichia coli, Klebsiella, Citrobacter diversus, Proteus, Providencia, Aeromonas hydrophila and Streptococcus. MIC90S for other Enterobacteriaceae were greater than or equal to 2 micrograms/ml; 44% of those strains were inhibited by less than or equal 1 microgram/ml. Staphylococcus, Psuedomonas aeruginosa and Enterococcus faecalis were resistant to cefixime.