Antimicrobial activity and β-lactamase stability of SK&F 88070 compared with other agents

Abstract The in vitro activity and β-lactamase stability of SK&F 88070 (7-[[2-amino-4-thiazo-lyl)(methoxyimino)acetyl]amino]-3-[[[1-(2-sulfaminoethyl)-1H-tetrazol-5-yl]thio]methyl]-3-cephem-4-carboxylic acid) a new parenteral cephalosporin was investigated against 780 types of bacteria. SK&F 88070 inhibited 90% of Escherichiacoli, Klebsiellapneumoniae, Proteusmirabilis, Salmonella species, Shigella species, Morganellamorganii, and Citrobacterdiversus at ≤0.5 μ g/ml. Its activity against these species was similar to cefotaxime and moxalactam and superior to cefoperazone and piperacillin. It was less active than cefoperazone against Pseudomonasaeruginosa and less active than cefotaxime or cefoperazone against Staphylococcusaureus. SK&F 88070 inhibited hemolytic streptococci and Streptococcuspneumoniae at ≤0.12 μ g/ml. Enterobacter species, Citrobacterfreundii, and Serratia, which were resistant to cefotaxime and moxalactam were resistant to SK&F 88070. It was not hydrolyzed by plasmid β-lactamases, but was hydrolyzed by the Proteusvulgaris type 1c enzyme. SK&F 88070 inhibited Richmond-Sykes type 1a β-lactamases.