Bacteroides penicillinase

Penicillin resistance and penicillinase production in clinical isolates of Bacteroides melaninogenicus.

The minimum inhibitory concentrations (MIC) of penicillin and six other antimicrobials were determined for 50 clinical isolates of Bacteroides melaninogenicus. Agar dilution susceptibilities were performed using supplemented brucella blood agar and the proposed National Committee for Clinical Laboratory Standards standard method for anaerobes; results with the two methods were comparable. A pen...

New Assay for Penicillinase and Some Results on Penicillinase Induction.

Imsande, John (Western Reserve University, Cleveland, Ohio). New assay for penicillinase and some results on penicillinase induction. J. Bacteriol. 89:1322-1327. 1965.-A rapid, sensitive, and reliable assay of penicillinase activity is described. Studies conducted on the induction of penicillinase, with use of the new assay, show that actinomycin D inhibits growth and the induced synthesis of p...

Studies on Penicillinase

On alkaline hydrolysis, penicillins are converted into penicilloic acids (1). Penicillinase appears to bring about the same transformation, in which a carboxyl group of pK 4.7 is generated (2). Foster (3) allowed penicillinase to act on penicillin in bicarbonate buffer in the Warburg respirometer and observed the evolution of COZ. Since such a reaction can be followed simply and with considerab...

Immunological specificity of Staphylococal penicillinase

Regulation of penicillinase synthesis: a mutation in Staphylococcus aureus unlinked to the penicillinase plasmid that reduced penicillinase inducibility.

A mutant of Staphylococcus aureus strain 655 was isolated that is restricted in penicillinase induction. Wild-type plasmids that bear penicillinase determinants could not be fully induced in this mutant, 655par-1; hence, the responsible mutation is not located on the plasmid. Mutant plasmid PI(258)penI443, which produces penicillinase constitutively in wild-type cells, was fully constitutive fo...