title: PS-6 and PS-7, new beta-lactam antibiotics. In vitro and in vivo evaluation.
abstract: Biological properties of two new beta-lactam antibiotics, PS-6 and PS-7, containing the carbapenem nucleus were studied. The in vitro activities of PS-6 and PS-7 were tested against clinical isolates of Gram-positive and Gram-negative bacteria in comparison with those of cefazolin, ampicillin and PS-5. In general, the antibacterial spectra of PS-6 and PS-7 were similar to that of PS-5. PS-7 was slightly less active than PS-5 and ABPC against Staphylococcus aureus. Clinical isolates of Gram-negative bacteria were found to be 2- to 8-fold more resistant to PS-6 than to PS-5, while PS-7 was 2-fold more active than PS-5 against Enterobacter, Klebsiella, Proteus, Serratia and Escherichia coli. The therapeutic effect of PS-6 seemed slightly less than that of PS-5 in an experimental infection with Staph. aureus Smith in mice.
mesh_terms: D000667:Ampicillin / Q000494:pharmacology; D000818:Animals; D000900:Anti-Bacterial Agents / Q000097:blood / Q000494:pharmacology* / Q000627:therapeutic use; D001419:Bacteria / Q000187:drug effects; D002437:Cefazolin / Q000494:pharmacology; D008297:Male; D051379:Mice; D008826:Microbial Sensitivity Tests; D013203:Staphylococcal Infections / Q000188:drug therapy; D013845:Thienamycins; D047090:beta-Lactams / Q000097:blood / Q000494:pharmacology / Q000627:therapeutic use
chemical_list: D000900:Anti-Bacterial Agents; D013845:Thienamycins; D047090:beta-Lactams; C027836:antibiotic PS 7; C027835:antibiotic PS 6; D000667:Ampicillin; D002437:Cefazolin