The Isolated and Purified β-lactamase from Local Isolate of Staphylococcus aureus

β-lactamase was isolated from local isolate of Staph. aureus, which elicited its resistance to penicillin–G, and rapid β-lactamase production. β-lactamase has been purified by using gelfiltration chromatography in sephadex G–100 column. The molecular weight of purified βlactamase was estimated by SDS-poly acryl amide gel electrophoresis and shown one band protein with molecular weight of 30 kDa. Antiserum was prepared for purified β-lactamase in rabbits, the measurements of antibodies titer were done by using passive haemagglutination test and it equaled to 40960, which indicated the immunogenicity of purified β-lactamase. The neutralization of β-lactamase activity by antiserum was performed in vitro, so Staph. aureus isolates regained their sensitivity to penicillin–G.