Emergence of fluoroquinolone resistance among multiply resistant strains of Streptococcus pneumoniae in Hong Kong

The MICs of 17 antimicrobial agents for 181 Streptococcus pneumoniae strain s were determined by the E-test. Overall, 69.1% were penicillin resistant ( MIC > 0.06 mu g/ml). Resistance to ciprofloxacin (MIC > 2 mu g/ml), levoflo xacin (MIC > 2 mu g/ml), or trovafloxacin (MIC > 1 mu g/ml) was found in 12 .1, 5.5, or 2.2% of the strains, respectively. These high rates of resistan ce raise concerns for the future.