Inhibition of cell-wall-mucopeptide formation in Escherichia coli by benzylpenicillin and 6-[d(−)-α-aminophenylacetamido]penicillanic acid (ampicillin)

Abstract

Benzylpenicillin inhibits cell-wall-mucopeptide synthesis as measured by the incorporation of [14C] glucose into bound [alpha][epsilon]-diaminopimelic acid. A new penicillin 6[D([long dash])-[alpha]-aminophenyl-acetamido] penicillanic acid (ampicillin) also has the same effect, (50 [degree]/o inhibition being found at 4 Mg/ml). About 40 Mg of benzylpeni-cillin/ml is needed to produce a comparable inhibition. It is concluded that penicillin has the same action in Gram-negative and Gram-positive bacteria.