Therapy of infections caused by mixed cultures ofEscherichia coli andStreptococcus faecalis

The antibacterial efficacy of ampicillin, mezlocillin, piperacillin, and cefotaxime against antagonistic mixed infections ofEscherichia coli andStreptococcus faecalis was studied by adopting an acute as well as a chronic animal model. Data obtained by both models revealed that ampicillin and, especially, mezlocillin were equally effective againstE. coli andS. faecalis whereas piperacillin and cefotaxime selected the enterococci from the mixed infections while eliminatingE. coli from the infected foci.