Abstract
The antibacterial activities of twelve 5, 6-cis carbapenem antibiotics, including four semisynthetic derivatives of C-19393 H2 and S2, against 15 microorganisms were examined, and their structure-activity relations are discussed in relation to minimum inhibitory concentrations against Staphylococcus aureus and Escherichia coli as a Gram-positive and a Gram-negative standard strain, respectively. The contribution of chromosomal β-lactamase (amp C), permeability barrier, and penicillin-binding protein (PBP) 1B to the resistance of E. coli to these carbapenem antibiotics was examined using mutants lacking each of these cellular components.
