超广谱β-内酰胺酶的检测及耐药性分析

目的 :了解产超广谱 β-内酰胺酶 (ESBL)肺炎克雷白杆菌、大肠埃希氏杆菌、阴沟肠杆菌的发生率、耐药性及耐药特点 ,指导用药。方法 :应用双纸片协同试验法对从临床感染标本中分离出的 2 1 5株革兰氏阴性菌作 ESBL的检测 ,比较亚胺培南等 1 4种抗生素对产 ESBL耐药菌体外抗菌作用。结果 :产 ESBL耐药菌占全部分离菌的 3 4.4% ,其中 ,大肠埃希氏杆菌占 47.3 % ,肺炎克雷白杆菌占 2 8.4% ,阴沟肠杆菌占 2 4.3 %。各类细菌中产 ESBL所占的比例分别是 ,大肠埃希氏杆菌为 3 1 .8% (3 5 /1 1 0 ) ,肺炎克雷白杆菌为 3 9.6% (2 1 /5 3 ) ,阴沟肠杆菌为 3 4.6% (1 8/5 2 )。在产 ESBL菌中 ,有 3株大肠埃希氏杆菌及 2株肺炎克雷白杆菌均同时对头孢噻肟和头孢他啶敏感。亚胺培南对产 ESBL耐药菌均表现出最强的抗菌作用 ;头孢西丁对产 ESBL肺炎克雷白杆菌及大肠埃希氏杆菌呈现出较好的抗菌作用。产 ESBL耐药阴沟肠杆菌对头孢西丁全部耐药 ;氨基糖苷类、氟喹诺酮类及磺胺类药物对产 ESBL肺炎克雷白杆菌、大肠埃希氏杆菌、阴沟肠杆菌有较高的交叉耐药性。结论 :对产 ESBL耐药菌感染不容忽视 ,对此类感染的治疗亚胺培南可作为首选。

DETECTION OF EXTENDED-SPECTRUM β-LACTAMASES AND RESISTANT ANALYSIS

Objective: To determine the prevalence of strains producing ESBL among Klebsiella pneumoniae, Escherichia coli and Enterobacter cloacae, and investigate the antibiotic resistance of these strains. Methods: 215 isolates of gram-negative bacilli from clinical infectious specimens were determined for the strains producing ESBL by double-disk synergy tests and antibiotic susceptibility test by Kirby-Bauer test. In vitro antibacterical activity of 14 kinds of antibiotics against those strains producing ESBL were compared. Results: Incidence rate of ESBL was 34.4%totally,and incidence rate of ESBL in E.coli, K.pneumoniae and E.cloacae was 47.3%,28.4%,24.3% respectively.Incidence rate of ESBL in E.coli, K.pneumoniae and E.cloacae was 31.8%,39.6%,34.6% respectively in every bacilli.In ESBL-producing strains, there was 2 strains of K.pneumoniae and 3 strains of E.coli which were susceptible to cefotaxime and ceftazidime simultaneously.Imipenem has the potent antibacterial activity to resistant strain producing ESBL .Cefoxitin has higher antibacterial activity to K.pneumoniae and E.coli producing ESBL,E.cloacae producing ESBL were all resistant to cefoxitin. All ESBL-producing strains had higher cross resistance rate to aminoglycosides, fluoroquinolones, sulfonamides.Conclusion: Due to gram-negative producing ESBL,infections should not be neglected.Imipenem should be the first choice to treat this kind of infections.