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

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.