临床常见革兰氏阴性菌产超广谱β-内酰胺酶的耐药性分析及意义

Resistant analysis and clinical significance of frequent Gram-negative bacilli producing Extended-Spectrum β-Lactamases

目的 :分析临床常见革兰氏阴性菌产超广谱 β 内酰胺酶 (ExtendedSpectrum β lactamase ,ESBLs)的产生及对 11种抗菌药物的耐药情况 ,并对临床针对性治疗产ESBLs耐药菌感染提出了建议。方法 :采用VITEKESBL检测试验及双纸片协同试验 ,对从临床感染标本中分离出的 2 81株革兰氏阴性菌作ESBLs的检测 ,比较亚胺培南等 11种抗菌药物对产ESBLs耐药菌体外抗菌作用。结果 :产ESBLs耐药菌占全部分离菌的2 3.1% ,其中大肠埃希氏菌占 49.2 % ,肺炎克雷伯氏菌占 2 3.1% ,阴沟肠杆菌占 15 .4% ,铜绿假单胞菌占7.7%。在耐三代头孢菌素阴性菌中 ,各类细菌中产ESBLs所占的比例分别是 ,大肠埃希氏菌为 5 7.1% ,肺炎克雷伯氏菌为 43.5 % ,阴沟肠杆菌为 2 1.3% ,铜绿假单胞菌为 14 .3% ,弗氏柠檬酸杆菌及乙酸钙不动杆菌各有 1株。在产ESBLs菌中 ,有 4株肺炎克雷伯氏菌及 12株大肠埃希氏菌均同时对头孢噻肟和头孢他啶敏感。亚胺培南除对产ESBLs铜绿假单胞菌抗菌作用明显降低外 ,对其它产ESBLs耐药菌均表现出最强的抗菌作用 ;头孢西丁对产ESBLs肺炎克雷伯氏菌及大肠埃希氏菌有较好的抗菌作用 ,其它产ESBLs耐药菌对头孢西丁全部耐药 ;氨基糖苷类及氟喹诺酮类抗菌药物对产ESBLs肺炎克雷伯氏菌呈现出较好的抗菌作用 。

Objective: To analyze the resistance of the clinical common gram negative bacilli producing ESBLs to 11 kinds of antimicrobial agents and suggest the appropriate use of antibiotics. Method: 281 isolates of gram negative bacilli from clinical infectious specimens were screened for the strain producing ESBLs by the VITEK ESBL detection test and double disk synergy tests. In vitro antibacterical activity of 11 kinds of antibiotics against the strain producing ESBLs were compared. Result: Incidence rate of ESBLs was 23.1%, and incidence rate of ESBLs in E.coli, K.pneumoniae, E.cloacae and P.aenuginosa was 49.2%, 23.1%, 15.4% and 7.7% respectively. In resistance of gram negative bacilli to the third generation cepphalosporin, incidence rate of ESBLs in E.coli, K.pneumoniae, E.cloacae and P.aenuginosa was 57 1%, 43 5%, 21 3% and 14 3% respectively. There was one ESBL producing strain in C.freundii and A.calcoacticus respectively. In ESBL producing strains, there were 4 strains of K.pneumoniae and 12 strains of E.cloi which were susceptible to cefotaxime and cetazidime simulataneously. Imipenem has the potent antibacterial activity to resistant strains producing ESBLs except P.areuginosa . Cefoxitin has higher antibacterial activity to K.pneumoniae and E.coli producing ESBLs. However, other strains producing ESBLs were all resistant to cefoxitin. Aminoglycosides and fluoroquinolone showed better activity to K. pneumoniae producing ESBls, but other resistant srains producing ESBLs showed obviously cross resistance to the two kinds of antibacterial agents. Conclusion: Due to gram negative producing ESBLs,infections should not be neglected. Imipenem should be the first choice to treat this kind of infections.