鲍氏不动杆菌耐药性及对亚胺培南耐药机制的研究  

Resistant Characteristic and Mechanisms of Imipenem Resistance in Acinetobacter baumannii

作　　者：冯红军[1] 王晶晶[2] 王邦松[2] 张永虎[2] 朱小娜[2] 

机构地区：[1]平顶山市第一人民医院消化内科,河南平顶山467000 [2]温州医学院附属第一医院感染科,浙江温州325000

出　　处：《中华医院感染学杂志》2009年第6期608-610,共3页Chinese Journal of Nosocomiology

摘　　要：目的了解多药耐药鲍氏不动杆菌耐药谱,研究鲍氏不动杆菌对亚胺培南的耐药性及耐药机制。方法用VITEK60型全自动药敏分析系统鉴定药敏系统及纸片扩散法进行药敏试验;酶三维试验检测ESBLs和AmpC酶;PCR扩增和测序分析检测碳青酶烯酶VIMI、MP、OXA-23和OXA-24;SDS-PAGE方法研究外膜蛋白表达情况;利血平协同抑制试验检测膜外排机制。结果156株多药耐药菌中有120株来自痰液(76.9%),其次是各种创面分泌物16株;病区分布则以ICU为主51株;头孢哌酮/舒巴坦耐药率最低,其次是亚胺培南,20株亚胺培南耐药菌中,ESBLs和AmpC酶阳性株分别为10株(50.0%)和20株(100.0%),PCR扩增VIM、IMP和OXA-24均阴性;OXA-23基因扩增显示19株(95%)阳性,PCR产物并经序列分析证实为OXA-23;与敏感株相比,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ICU是多药耐药鲍氏不动杆菌最主要的感染科室,碳青酶烯类抗菌药物的长期广泛应用使鲍氏不动杆菌的耐药率不断升高;产OXA-23型β-内酰胺酶是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鲍氏不动杆菌对亚胺培南耐药有密切关系。OBJECTIVE To investigate the resistance of Acinetobacter baumannii （ABA）, and the mechanism of imipenem resistance in A. baumannii. METHODS All specimens were identified by VITEK-60 and the drug resistance was detected by Kirby-Bauer test. Three dimensional test was used to detect ESBLs and AmpC. PCR and DNA sequencing were performed to determine VIM, IMP, OXA-23 and OXA-24 β-lactamases. Outer membrane protein was analyzed by SDS-PAGE, Reserpine synergistic inhibition test was used to study the active efflux mechanism. RESULTS Totally 120 strains were isolated from sputum （76. 9%） , and 16 strains from secretion （10.3%）. ICU was the main infected department （51 strains, 32.7%）. The resistance to sulperazone was the lowest （20.5 %）, and to imipenem accounted for 38.5 %, Of the 20 imipenem resistant strains, 10 strains were ESBLs positive （50%）, and 20 strains were AmpC positive （100%）. VIM, IMP and OXA-24 β-1actamases were not detected out, 19 strains （95%） produced OXA-23. Compared to the imipenem-sensitive strains, the resistant strains lacked the outer membrane protein of 22 × 10^3 , 29 × 10^3 and 33 × 10^3. The MICs of A. baumannii to imipenem were not decreased by reserpine which demonstrated that excretive mechanism was negative. CONCLUSIONS ICU is the main infected department for ABA. The resistance rate is increasing for longer-term usage of carbopenem; OXA-23 production is the important resistance mechanism in ABA, AmpC production and outer membrane protein lacking show close relation to the drug-resistance in A. baumannii.

关 键 词：鲍氏不动杆菌 亚胺培南 耐药机制 

分 类 号：R378[医药卫生—病原生物学]