革兰阴性杆菌去阻遏持续高产AmpC酶检测及耐药性分析

Study on detection of hight-level AmpC enzyme and analysis of drug resistance in gram-negtive bacteria

目的:了解近期临床分离的30株革兰氏阴性杆菌去阻遏持续高产AmpC酶情况及对15种抗菌药物的耐药性,并对三种AmpC酶检测方法进行比较,为临床提供常规检测和用药的参考。方法:用头孢西丁药敏法、表型筛选法和三维实验法分别检测AmpC酶,用纸片扩散法进行体外药敏实验。结果:头孢西丁药敏法、表型筛选法和三维实验法的AmpC酶检出率分别为56.7%、13.3%、10.0%,头孢西丁药敏实验与三维实验相比,存在较高假阳性率82.4%,表型筛选法与三维实验符合率达96.7%;17株耐头孢西丁菌株的药敏实验显示出严重的多重耐药,对青霉素类及加β-内酰胺酶抑制剂克拉维酸的复合药物、氨基糖苷类均呈高比例耐药,对加β-内酰胺酶抑制剂舒巴坦和他唑巴坦的头孢菌素类较为敏感,而对亚安培南和头孢肶肟的敏感率达100%。结论:表型筛选法操作简单省时,且准确率高,适合临床推广使用;治疗产AmpC酶菌感染以亚安培南和第四代头孢菌素头孢肶肟较优。

Objective： To investigate the status of resistance of 30 clinical Isolats to 15 kinds of antibiotics and expression of high-level AmpC enzyme. To compare three methods of detection of AmpC enzyme. To help clinical detection and drug use. Methods：K-B tests were performed to detect the susceptibility of antimicrobial agents. AmpC enzyme was detected by cefoxitin test, phenotype sceening method, three-dimensional test. Results：The detective rate of AmpC enzyme of cefoxitin test, phenotype sceening method, three-dimensional test is 56. 7%, 13.3%, 10.0%. Campared with three-dimensional, cefoxitin test have high false positive rate of 82. 4%, phenotype sceening method and three-dimensional test have high coincidence of 96.7%, Susceptibility test of antimicrobial agents showed multidrug resistant of 17 isolats that resistant to cefoxitin, including penicillins, compound medicine with clavulanic acid and aminoglycosides, the sensitive rate to compound medicine with sulbactam and tazobactam was high, the sensitive rate to impenam and cefepime was up to 100%. Conclusion：Phenotype sceening method was easy to handling and save time, so fit to used in hospital; The therapy of infection caused by AmpC enzyme positive strains had better chose impenam and cefepime.