Nafcillin and oxacillin: comparative antistaphylococcal activity in mice.

The therapeutic properties of nafcillin, oxacillin and erythromycin were determined in mice infected with a strain (Evans) of Staphylococcus aureus shown to be tolerant to the bactericidal action of penicillinase-resistant derivatives of penicillin. The therapeutic activity of these agents was also correlated with the extent of colonization of kidneys by resistant clones of S. aureus Evans.

Amide Penicillin Wy-12,556: therapeutic activity in animals subjected to repeated bacterial infection.

Amide penicillin Wy-12,556 and DBED penicillin were studied for their antibacterial effect in CD-1 mice repeatedly infected with Streptococcus pyogenes C203 and/or Staphylococcus aureus Smith. Animals infected with S. aureus Smith failed to show a difference between the therapeutic activity of DBED penicillin and Wy-12,556.

Synthesis and antibacterial evaluation of 1,2,3,4-tetrahydro-4-oxo-1,8-naphthyridine-3-carboxylic acid esters, carbonitriles, and carboxamides.

A series of 1,2,3,4-tetrahydro-4-oxo-1,8-naphthyridine-3-carboxylic acid esters, carbonitriles, and carboxamides (2a-k) was synthesized and initially evaluated (dose range 50-400 mg/kg) in mice infected with Escherichia coli. Only two derivatives, the ethyl and butyl esters of 1-ethyl-1,2-dihydro-4-hydroxy-7-methyl-1,8-naphthyridine-3-carboxylic acid, protected the animals against E. coli and several other gram-negative bacterial pathogenic infections.