Study on of β-lactamases Stability of Cefpirome,a New Fourth Generation Cephalosporin

Objective The enzymatic stability of cefpirome to β-lactamase extracts taken from 8 both plasmid and chromosome-mediated β-lactamases producing strains was studied, and compared with the other four cephalosporins. Methods The stability of several β-lactams to crude β-lactamases were determined and compared by means of an ultraviolet spectrophotometer, after the extraction of crude enzymes from the tested bacteria. Results The relative hydrolysis rates of cefpirome were less than 5% of all the β-lactamases determined above, cefpirome was more stable to TEM-3、SHV-4 and chromosome-mediated β-lactamases than the third generation cephalosporin cefotaxime and other cephalosporins. Conclusions Cefpirome is highly stable to β-lacamases.