大肠杆菌为临床感染中最常见的病原菌之一。由于氟喹诺酮类药物的不合理使用，导致大肠杆菌耐药菌株的大量出现，其耐药性亦不断发生变迁，给患者治疗带来极大困难。我们测定了大肠杆菌44102等5株细菌对环丙沙星、氧氟沙星和诺氟沙星的耐药突变频率。用亚MIC（最低抑菌浓度）连 Escherichia coli is one of the most common pathogens in clinical infection. Due to the unreasonable use of fluoroquinolones, which led to the emergence of a large number of drug-resistant strains of E. coli, the drug resistance has also been constantly changing, posing great difficulties for the treatment of patients. We measured the frequency of drug-resistant mutations in ciprofloxacin, ofloxacin, and norfloxacin in 5 strains of bacteria such as E. coli 44102. With sub MIC (minimum inhibitory concentration) even