摘要
目的研究鲍氏不动杆菌对亚胺培南的耐药机制。方法检测62株鲍氏不动杆菌的耐药性,对其中对20株耐亚胺培南鲍氏不动杆菌进行耐药机制研究;检测ESBLs、AmpC酶、VIM、IMP、OXA-23和OXA-24产生及外膜蛋白表达情况,利血平协同抑制试验检测膜外排机制。结果鲍氏不动杆菌对亚胺培南耐药率为41%;对20株耐亚胺培南菌株中,ESBLs和AmpC酶阳性率分别50%和100%,VIMI、MP、OXA-24均阴性,OXA-23阳性率为95%;部分菌株存在22×103、29×103、33×103的外膜蛋白缺失;利血平不能降低亚胺培南对鲍氏不动杆菌的MIC值。结论产OXA-23型β-内酰胺酶是本院鲍氏不动杆菌对亚胺培南耐药的重要原因,产AmpC酶合并外膜蛋白缺失与耐亚胺培南鲍氏不动杆菌有密切关系。
OBJECTIVE To investigate the resistant mechanism of imipenem in Acinetobacter baumannii. METHODS Antimicrobial susceptibility was tested by agar dilution method, resistant mechanism was studied by 20 strains of imipenem-resistant A. baumannii. ESBLs, AmpC, VIM, IMP, OXA-23, OXA-24 and outermembrane protein were detected. Reserpine synergistic inhibition test was used to study the active efflux mechanism. RESULTS Among 62 A. baumannii strains, resistance to imipenem accounted for 41.0%; of the 20 imipenem-resistance strains, there were ESBLs positive in 50 %, AmpC in 100 % ; VIM, IMP, and OXA-24 were all negative; 95 % strains produced OXA-23; some resistant strains lacked the outermembrane protein with relative molecular mass about 22×10^3 , 29×10^3 and 33 ×10^3. The MICs of imipenem against A. baumannii couldn＇t be decreased by reserpine. CONCLUSIONS OXA-23 production is the important mechanism of imipenem resistance, AmpC production and lack in outermembrane protein are responsible for imipenem resigtance in A. baumannii.
出处
《中华医院感染学杂志》
CAS
CSCD
北大核心
2007年第4期375-378,共4页
Chinese Journal of Nosocomiology
基金
浙江省教育厅资助项目(SJY20041052)
关键词
鲍氏不动杆菌
亚胺培南
耐药性
机制
Acinetobacter baurnannii
Imipenem
Drug resistances Mechanism
