Activity of cefotaxime and metronidazole against bacteroides and Escherichia coli alone and in mixed culture.

The activity of cefotaxime and metronidazole against one strain of Escherichia coli and three of Bacteroides has been studied. A fixed cefotaxime concentration (8 mg/l) did not kill E. coli in presence of Bacteroides due to degradation of the drug by the anaerobe. However, the presence of metronidazole in the same system killed Bacteroides strains very effectively and prevented the degradation of cefotaxime which killed E. coli.