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Cefoperazone, a new semisynthetic cephalosporin, has a broad spectrum of antibacterial activity. It is as active as cefazolin and cefamandole against grampositive bacteria and is more active than cefazolin and cefamandole against such gram-negative bacilli as Escherichia coli, Klebsiella pneumoniae, Proteus species, Pseudomonas aeruginosa, Citrobacter freundii, Enterobacter cloacae, and Serratia marcescens. The superiority of cefoperazone over cefazolin and cefamandole with respect to activity against P. aeruginosa by more than 200-fold was especially remarkable. As with other,8-lactam antibiotics, there was only a small spread between the minimum inhibitory concentrations and the minimum bactericidal concentrations of cefoperazone and a significant decrease in activity with an increase in inoculum size. Activity was not altered significantly by the addition of human serum to the test medium. Cefoperazone is relatively stable to hydrolysis to ,8-lactamases produced by gram-negative bacteria. Relative rates of hydrolysis of cefoperazone by cephalosporinases are 7.0 to 0.01, with reference to cephaloridine hydrolysis (base, 100). Cefoperazone is also more stable than penicillin G and cephaloridine to various types of penicillinases.Cefoperazone (T-1551) (CPZ), the sodium salt of 7[D(-)-a-(4-ethyl-2,3-dioxo-1-piperadine-carboxamide) -a -(4 -hydroxyphenyl)acetamido] -3 -[(1-methyl-lH-tetra zol-5-yl)thiomethyl]-3-cephem-4-carboxylate (Fig. 1), has a broader spectrum of activity than related cephalosporins, including cefamandole (CMD) and cefazolin (CEZ) and is significantly active against Pseudomonas aeruginosa, Serratia marcescens, and Enterobacter cloacae. The current report summarizes our observations on the in vitro antibacterial activity of this new cephalosporin and its stability to 8i-lactamases.

No abstract

The mutations in the quinolone-resistance determining regions (QRDR) of the gyrA, gyrB and grlA genes and in the norA gene from five clinical isolates of methicillin resistant Staphylococcus aureus (MRSA) were examined by DNA sequencing. The mutation from Ser84 to Leu in GyrA was associated with relatively high-level resistance to quinolones, whereas the mutation from Glu88 to Gly or Lys in GyrA was associated with low-level resistance to quinolones. Mutations of the grlA gene were observed at codon 80 (Ser80) or 84 (Glu84), independent of the mutations of gyrA. No mutations were observed in either the gyrB or norA genes.

The purified cephalosporinase from Proteus vulgaris hydrolyzed a variety of cephalosporins, including cefuroxime, at a high level; its activity was inhibited by clavulanic acid.