Author(s): Shi Yao-guo, Wu Pei-jun, Wang Fu, Liu Yu-kun and Dai Zi-ying
Pages: 263-267
Year: 1985 Issue:  5
Journal: Chinese Journal of Antibiotics
Keyword:  质粒介导; 染色体介导; 噻肟单酰胺菌素; 新药筛选; 内酰胺类抗生素; 产酶菌; 羟羧氧酰胺菌素; 肉汤培养基; 二代头孢; 为高;
Abstract: The stability of 17 cephalosporins to 11 β-lactamases were studied in our laboratory. Activities of 11 β-lactamases were determined spectrophotometrically, nitrocefin used as the substrate. The hydrolysis rates of 17 cephalosporins by 11 β-lactamases were determined by ultraviolet spectrophotometry and given as values relative to that of cephaloridine, taken as 100. Results of experiment revealed that activity of 2 chromsome-mediated β-lactamases D-31 and K-1 was relatively high, being 22.00u/ml and 145.00u/ml respectively; while that of 9 plasmid-mediated β-lactamases was usually low,in the range of 0.41-17.40 u/ml.Among the first genarat-ion cephalosporins, cephradine was resistant to most β-lactamases,and the stability to different β-lactamases of others was very much variable. With exception of cefamandole and cefaperazone, all cephalosporins of the second and the third genaration were very stable to most β-lactamases.The stability of cephalosporin antibiotics to the different types of β-lactamase may be used as one of the index of screening new drugs.