An Immunological Study of the Constitutive and the Penicillin-induced Penicillinases of Bacillus cereus, Based on Specific Enzyme Neutralization by Antibody

Abstract

SUMMARY: Exocellular penicillinases from strains 569 and 5/B of Bacillus cereus gave almost identical activity-neutralization curves when titrated with antisera prepared against the enzyme from either strain; but were easily distinguishable by differences in their neutralization reaction with an anti-569 penicillinase serum previously partially absorbed with either the 5/B or the 569 enzyme. By contrast, no differences in neutralization reaction were detected between basal and induced penicillinase from strain 569 and the constitutive penicillinase from strain 569/H (a mutant derived from strain 569), when treated with samples of the anti-569 penicillinase serum, previously partially absorbed with each penicillinase preparation separately. Strain 569 was not found to produce any substance in significant quantities capable of combining with anti-penicillinase neutralizing antibodies other than penicillinase itself.