环丙沙星及亚胺培南体内、外诱导交叉耐药铜绿假单胞菌

Cross resistance of Pseudomonas aeruginosa induced by ciprofloxacin and imipenem in vitro and in vivo

目的：研究环丙沙星及亚胺培南体内、外诱导铜绿假单胞菌交叉耐药的耐药诱导性。方法：以铜绿假单胞菌临床分离敏感株ＰＡ５，利用含药琼脂平板法（ＭＨ 琼脂）及小鼠铜绿假单胞菌腹膜炎动物模型，研究两药体内、外诱导交叉耐药情况。结果：体外环丙沙星及亚胺培南在１×ＭＩＣ、２×ＭＩＣ浓度可诱导耐药菌产生，交叉耐药率９．２％及２０．８％。体内环丙沙星诱导产生交叉耐药率为３．８％。结论：铜绿假单胞菌交叉耐药菌均可经环丙沙星或亚胺培南在体内、外诱导选择产生。体外环丙沙星与亚胺培南诱导选择耐药突变频率及交叉耐药率无明显差异，体内交叉耐药菌的产生与药物剂量相关。

Objective: To investigate ciprofloxacin and im ipenem in vitro and in vivo inducibility on Pseudomonas aeruginosa cross resistan ce.Methods：The cross resistance mutant strains in vitro and in vivo were selec ted with clinically isolated sensitive strain of P.aeruginosa PA5 by passage on MH agar containing different concentrations of ciprofloxacin or imipenem and experimental murine peritonitis.Results： The cross resistance rate of P.ae ruginosa selected by 1 or 2×MIC ciprofloxacin and imipenem were 9.2% and 20.8%. The 4 strains of cross resistance mutants were obtained when ciprofloxacin therapeutic dosage were 10～25mg/kg.The 2 strains of cross resistance mutants were ob tained when imipenem therapeutic dosage were 5～10mg/kg.Conclusion： T he cross resistance mutants for ciprofloxacin and imipenem could be induced and selec ted in vitro and in vivo with both agents.There is no difference in resistance mutation frequency and cross resistance rate between ciprofloxacin and imipenem in vitro.The in vivo cross resistance is related with dosage.