R: resistant, S: susceptible, I: intermediate resistance, and NS: increased MIC. For levofloxacin (LVX), MIC of ≥8 mg/L: resistant, 4 mg/L: intermediate resistant, and ≤2 mg/L: susceptible. For norfloxacin (NOR), MIC of ≥4 mg/L: resistant; ≤1 mg/L: susceptible. For ciprofloxacin (CIP), MIC of >2 mg/L: resistant; ≤0.125: susceptible. Values which were in the range of 0.125 to 2 were considered as having reduced susceptibility (NS).