克拉维酸和舒巴坦两种酶抑制剂检测超广谱β-内酰胺酶的比较

Comparison of two enzyme inhibitors Clavulanic acid and Sulbactam for extended spectrum β-lactamase detection

为了比较克拉维酸和舒巴坦两种酶抑制剂检测超广谱 β 内酰胺酶 (ESBL)的差异。采用纸片扩散法检测了 30 7株 4种革兰阴性杆菌。两种酶抑制剂对大肠埃希菌检测结果一致 ;肺炎克雷伯菌两种酶抑制剂共同检出 8株 ,各单独检出 2株 ;铜绿假单胞菌共同检出 6株 ,克拉维酸单独检出 1株 ,舒巴坦单独检出 7株 ;鲍曼不动杆菌共同检出 7株 ,舒巴坦单独检出 17株 ,克拉维酸单独未检出。底物的轮廓 (substrateprofile)对酶的检测有较大的影响 ,尽管两种酶抑制剂检测大肠埃希菌无差异 ,而肺炎克雷伯菌可能存在Bush模式以外的超广谱 β 内酰胺酶 ,铜绿假单胞菌和鲍曼不动杆菌耐药机理尚需进一步研究 ,以目前的方法检测ESBL不合适。

To compare difference between two enzyme inhibitors Clavulanic acid(CA) and Sulbactam(SB)for detecting extended spectrum β lactamase(ESBL).307 strains of Grams negative bacteria of 4 species were examined by disk diffusion method.For E.coli,the results of ESBL detected with two kinds of enzyme inhibitors were same;for K.pneumoniae,8 strains were positive with both CA and SB while 2 positive with CA and 2 positive with SB each;for P.Aeruginosa ,6 positive with CA and SB,1 positive only with CA and 7 positive only with SB;for A.baumanii,7 were positive with CA and SB,17 positive with SB and no positive with CA alone.Substrate profile could influence detection of enzyme.Although there is no difference between CA and SB for detecting ESBL of E.Coli, there may be other patterns ESBL in addition to Bush model in K.pneumoniae. For P.aeruginosa and A.baumanii,mechanisms of resistance to β lactam antibiotics requires farther research,the commonly used methods of detecting ESBL are not suitable.