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

The in vitro activity and beta-lactamase stability of SK&F 88070 (7-[[2-amino-4-thiazolyl)(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 Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Salmonella species, Shigella species, Morganella morganii, and Citrobacter diversus at less than or equal to 0.5 micrograms/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 Pseudomonas aeruginosa and less active than cefotaxime or cefoperazone against Staphylococcus aureus. SK&F 88070 inhibited hemolytic streptococci and Streptococcus pneumoniae at less than or equal to 0.12 micrograms/ml. Enterobacter species, Citrobacter freundii, and Serratia, which were resistant to cefotaxime and moxalactam were resistant to SK&F 88070. It was not hydrolyzed by plasmid beta-lactamases, but was hydrolyzed by the Proteus vulgaris type 1c enzyme. SK&F 88070 inhibited Richmond-Sykes type 1a beta-lactamases.