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Inhibition of Aerobacter Cephalosporin β-Lactamase by Penicillins

1969; American Society for Microbiology; Volume: 98; Issue: 2 Linguagem: Inglês

10.1128/jb.98.2.394-397.1969

1098-5530

Peter Fleming, M. Goldner, D.G. Glass,

Bacterial biofilms and quorum sensing

Cephalosporinase (β-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 μg of cephalosporin C per ml. Cloxacillin exerted a potentiating effect on the inhibition of the E. cloacae organisms by cephalosporin C.