Inhibition of Aerobacter cephalosporin beta-lactamase by penicillins.
Cephalosporinase (beta-lactamase) was obtained from cell washings of Aerobacter (Enterobacter) cloacae as a highly active preparation. An alkalimetric method was used to determine the enzyme activity and to estimate its inhibition by 6-amino-penicillanic acid derivatives. Their order of decreasing inhibitory effect was as follows: cloxacillin, oxacillin, methicillin, ampicillin, and penicillin G. We found that 2 to 3 ng of cloxacillin per ml was sufficient to decrease the enzyme activity by 50% in the presence of 400 mug of cephalosporin C per ml. Cloxacillin exerted a potentiating effect on the inhibition of the E. cloacae organisms by cephalosporin C.
D000667:Ampicillin / Q000494:pharmacology; D002511:Cephalosporins / Q000378:metabolism / Q000494:pharmacology; D003023:Cloxacillin / Q000494:pharmacology; D004754:Enterobacter / Q000201:enzymology*; D008712:Methicillin / Q000494:pharmacology; D010068:Oxacillin / Q000494:pharmacology; D010400:Penicillin G / Q000494:pharmacology; D010406:Penicillins / Q000494:pharmacology*; D065093:beta-Lactamase Inhibitors
D002511:Cephalosporins; D010406:Penicillins; D065093:beta-Lactamase Inhibitors; D000667:Ampicillin; D003023:Cloxacillin; D010400:Penicillin G; D008712:Methicillin; D010068:Oxacillin