肠杆菌科细菌产β-内酰胺酶的研究

Preliminary Study of Enterobacteriaceae Producing β-Lactamases

目的 研究肠杆菌科细菌产 β-内酰胺酶、超广谱 β-内酰胺酶 (ESBL s)与对头孢他啶 (CAZ)的耐药表型的关系。方法 Nitrocefin纸片检测 β-内酰胺酶的活性 ,双纸片协同试验 (DDST)筛查 ESBL s阳性菌株。结果 2 15株细菌产 β-内酰胺酶的阳性率分别为克雷伯菌属 73%、大肠埃希菌属 81%、肠杆菌属 83% ;对 CAZ的耐药率分别为 5 .3%、3.2 %、10 .9% ;其中对 CAZ的 MIC≥ 2 μg/ ml的比率分别为 2 4.0 %、2 4.5 %、5 8.7% ,DDST测 ES-BL s阳性有 16株 ,仅 2株对 CAZ耐药 ,14株 CAZ的 MIC处于 2～ 16 μg/ m l,大肠埃希菌阳性率最高 ,达 10 .6 %。结论 许多产 ESBL s菌株对 CAZ的 MIC呈敏感或中度敏感 ,大肠埃希菌尤为突出。

OBJECTIVE In order to study the relationship between Enterobacteriaceae producing β lactamases(ESBLs) and sensitivity to ceftazidime.METHODS β Lactamase activity was indicatcd by Nitrocefin disc. ESBL positive strains were detected by double disk tests.RESULTS Among 215 isolates studied, 73% of Klebsiella spp., 81%of Escherichia coli and 83% of Enterobacter spp.produced β lactamases, respectively.With them 5.3%,3.2%,10.9% isolates were resistant to ceftazidime(CAZ), respectively.Sixteen ESBL producing strains were detected by double disk tests, only 2 of them were resistant to CAZ, others were CAZ sensitive or CAZ intermediate strains(MIC of 2 to 16μg/ml).Escherichia coli was the most common ESBLs producing specics(10.6%).CONCLUSIONS Many isolates producing ESBLs were sensitive or intermediate to CAZ E.coli.