碳青霉烯类抗菌药物对大肠埃希菌、肺炎克雷伯菌、铜绿假单胞菌、鲍曼不动杆菌的防突变浓度研究

目的:探索碳青霉烯类抗菌药物对临床分离的100株大肠埃希菌、肺炎克雷伯菌β-内酰胺酶表型和铜绿假单胞菌、鲍曼不动杆菌的防突变浓度(MPC)。方法:采用琼脂稀释法测定碳青霉烯类(亚胺培南、美洛培南、厄他培南和多利培南)对临床分离的革兰阴性耐药菌株的最低抑菌浓度(MIC)及MPC并计算MPC/MIC比值。采用WHONET 5.6及SPASS 13.0进行分析。结果:肠杆菌科细菌和鲍曼不动杆菌的MPC/MIC比值为2~4,铜绿假单胞菌为4-≥16。β-内酰胺酶阳性的肺炎克雷伯菌、大肠埃希菌MPC/MIC比值高于β-内酰胺酶阴性菌株(4至 > 16 μg·mL^-1)。结论:基于MPC的碳青霉烯类抗菌药物可以通过MPC/MIC比值调整给药剂量,降低耐药菌株的总体数量和感染负荷,抑制耐药菌突变体的选择性富集扩增。

Mutant preventing concentrations of carbapenem antibiotics against Escherichia coli,Klebsiella pneumoniae,Pseudomonas aeruginosa,Acinetobacter Bauman

OBJECTIVE To explore mutant preventing concentrations (MPC) of carbapenem antibiotics against clinical isolates of 100 strains of Escherichia coli, Klebsiella pneumoniae ESBLs phenotype, Pseudomonas aeruginosa and Acinetobacter Bauman.METHODS Minimal inhibitory concentration (MIC) and MPC of carbapenems (imipenem, meropenem and ertapenem, doripenem) were determined using agar dilution method for gram negative strains of clinical isolates to calculate the ratio of MPC/MIC. WHONET 5.6 and SPASS 13.0 were used for analysis.RESULTS Real ratios of MPC/MIC were 2-4 for Enterobacteriaceae coli and Acinetobacter Bauman, and 4-≥16 for Pseudomonas aeruginosa. Beta lactamase positive Klebsiella pneumoniae and Escherichia coli had higher MPC/MIC ratios than those for beta lactamase negative strains (4 to >16 g·mL^-1). CONCLUSION Carbapenem antibiotics based on MPC can adjust dose according to MPC/MIC ratios, reduce total quantity and burden of infection resistant strains, inhibit selective enrichment and amplification of mutant resistant bacteria.