title: Antimicrobial and beta-lactamase inhibitory activities of carpetimycins A and B, new carbapenem antibiotics.
abstract: Carpetimycins A and B showed widely broad spectra and potent activity against gram-positive and gram-negative bacteria, including various species of anaerobic bacteria. The antimicrobial activity of carpetimycin A was 8 to 64 times greater than that of carpetimycin B and 4 to 128 times greater than that of cefoxitin. The inhibitory concentration of carpetimycin A required to inhibit more than 90% of clinical isolates was 0.39 micrograms/ml for Escherichia coli and klebsiella and 1.56 microgram/ml for Proteus and Staphylococcus aureus. At a concentration of 3.13 micrograms/ml, carpetimycin A inhibited almost all clinical isolates of Enterobacter and Citrobacter, which showed resistance to many clinically used beta-lactam antibiotics. Carpetimycins A and B furthermore were shown to have potent inhibitory activities against several kinds of beta-lactamases produced by beta-lactam-resistant strains; they inhibited not only penicillinase-type beta-lactamases but also cephalosporinase-type beta-lactamases, which were insensitive to clavulanic acid. In combination with beta-lactam antibiotics such as ampicillin, carbenicillin, and cefazolin, carpetimycins A and B showed synergistic activities against beta-lactam-resistant bacteria.
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D006736:Horses / Q000097:blood; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008826:Microbial Sensitivity Tests; D013845:Thienamycins; D065093:beta-Lactamase Inhibitors; D047090:beta-Lactams / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D013845:Thienamycins; D065093:beta-Lactamase Inhibitors; D047090:beta-Lactams; C030883:carpetimycin A; C030884:carpetimycin B