Enterococcal superinfection in patients treated with ciprofloxacin

Abstract
Two patients developed setious enterococcal superinfection following therapy with intravenous ciprofloxacin. The strains causing bacteraemia were susceptible to low concentrations of ciprofloxacin when tested at a standard inoculum. However, at an inoculum of 1 × 107 cfu/ml they were resistant to high concentrations of ciprofloxacin. Our data suggest that ciprofloxacin should not be used to treat patients with serious enterococcal infection and that patients treated with ciprofloxacin should be monitored carefully for the development of enterococcal superinfection.