双抑制剂扩散协同法检测AmpC酶和超广谱β-内酰胺酶

Double Inhibitors Diffuse Synergy Test of AmpC Enzyme and Extended-spectrum-β-Lactamases

目的探讨双抑制剂扩散协同法(double inhibitors diffuse synergr test,DIDST)检测AmpC酶和超广谱β-内酰胺酶(ESBLs)的临床应用价值。方法氯唑西林作为AmpC酶的抑制剂,而克拉维酸作为ESBLs的抑制剂,采用DIDST同时检测56株革兰阴性杆菌的AmpC酶和ESBLs,并以改良酶提取物三维试验和纸片扩散法确证试验分别作为AmpC酶和ESBLs的确证试验。结果DIDST检出单产AmpC酶菌株16株(28.6%),单产ESBLs菌株20株(35.7%),同时产AmpC酶和ESBLs菌株5株(8.9%)与改良酶提取物三维试验检测AmpC酶符合率为100%,而与纸片扩散法确证试验检测ESBLs的符合率均为96.4%。结论DIDST可同时检测AmpC酶和ESBLs,方法准确、简便,适用于临床微生物实验室。

Objective To consider the reliability of the double inhibitors diffuse synergy test （DIDST） to detect AmpC enzyme and extended-spectrum-β-lactamases （ESBLs）. Methods The cloxacillin were regarded as the inhibitors of AmpC enzyme,and the calvulanic were regarded as the inhibitors of ESBLs. Use DIDST to detect AmpC enzyme and ESBLs in 56 strains of gram negative bacilli at the same time. The modified three-dimensional extract test and phenotypic confirmatory test were used for the confirming of AmpC enzyme and ESBLs respectively. Results 16 strains（28.6%）were AmpC positive,20 strains（35.7%）were ESBLs positive,and 5 strains （8.9%）AmpC＋ESBLs positive were found using DIDST. The result of DIDST was similar to that of other two kinds of test. Conclusion DIDST is an accurate and handy method can detect AmpC enzyme and ESBLs at the same time. It is suitable for clinical microbiology laboratory.