Antibiotic resistance in Escherichia coli isolated from blood and cerebrospinal fluid: a 6-year study of isolates from patients in England and Wales.

A study of the incidence of resistance to antimicrobial drugs in Escherichia coli from blood and CSF made in England and Wales in the 6-year period 1991 1996 has demonstrated a significant increase in the incidence of strains resistant to ampicillin and ciprofloxacin, two antibiotics used for first-line therapy of invasive disease. In particular, there has been a dramatic change in the occurrence of isolates with low level or high level resistance to ciprofloxacin; over 90% of isolates in the high level group were also resistant to at least four other antimicrobials. Physicians in England and Wales should be aware that there is now an increasing possibility of treatment failures when ciprofloxacin is used for the treatment of invasive E. coli infections.