Ciprofloxacin-resistant Escherichia coli emerging in a rehabilitation medical center

A retrospective review of laboratory records from 1988 to 1996 has shown an increased rate of ciprofloxacin-resistant (cip r) Escherichia coli in our rehabilitation center. Resistance increased from 0.6% in 1989 to 5.9% in 1996. Of 7870 E. coli strains isolated during this period, 257 cip r- E. coli were recovered from 257 patients. The majority (96%) of these resistant strains were isolated from the urine samples. One hundred and twenty strains of cip r- E. coli were also resistant to four other fluoroquinolones. MICs ranging from 64 to 512 μg/mL were observed in 75% of the strains and ≥1028 μg/mL in 6.4% of the strains. Resistance to ciprofloxacin was due to possible mutations in topoisomerase gyrA.