碳青霉烯类抗生素体外抗菌活性及其耐药机制研究

In vitro activity of carbapenems and their resistance mechanism

目的:研究碳青霉烯类抗生素对临床分离菌的体外抗菌活性,分析其耐药机制。方法:采用平皿二倍稀释法测定4种碳青霉烯类抗生素对352株临床菌株的MIC值,应用PCR方法鉴定铜绿假单胞菌、鲍曼不动杆菌的耐药基因。结果:4种药物对除铜绿假单胞菌和鲍曼不动杆菌外的其他菌种非常敏感。从两种耐药菌中分别鉴定出VIM-2和OXA-23基因。结论:碳青霉烯类抗生素对大部分临床分离菌株的抗菌活性较好。OXA-23基因为鲍曼不动杆菌耐药的主要机制之一。

Objective： To determine the sensitivity and resistance in clinical strains to carbapenems,and investigate their carbapenemase genotypes.Methods： Totally 352 clinically isolated strains were collected from hospitals in Beijing,2007-2009.Their MIC to meropenem,imipenem/cilastatin,panipenem and faropenem were detected by the agar dilution method.The highly resistant strains,Pseudomonas aeruginosa and Acinetobacter baumannii,were chosen for PCR screening to find the carbapenemase genes.Results： Meropenem,imipenem/cilastatin,panipenem and faropenem were effective to most of the clinical isolates except Pseudomonas aeruginosa and Acinetobacter baumannii.The resistant Pseudomonas aeruginosa and Acinetobacter baumannii strains were identified carrying VIM-2 and OXA-23 genes,respectively.Conclusion： Carbapenems are effective against most clinical isolates.OXA-23 is one of the major causes in Acinetobacter baumannii resistance to carbapenems.