ANTIBACTERIAL ACTIVITY OF AC-1370

Abstract

AC-1370, a new semisynthetic cephalosporin, has a broad spectrum of antibacterial activity against gram-positive and gram-negative bacteria, especially Pseudomonas aeruginosa. It was active than cefazolin against gram-negative bacteria, such as Proteus species, Enterobacter cloacae, Serratia marcescens, Citrobacter freundii, Haemophilus influenzae and Neisseria gonorrhoeae, however, not so active as cefoperazone. Against P. aeruginosa, it was slightly less active than cefsulodin and cefoperazone, but more active than latamoxef. As with other beta-lactam antibiotics, there was only a small difference between the minimal inhibitory concentrations and the minimal bactericidal concentrations of AC-1370. It was relatively stable to the hydrolysis of beta-lactamases, especially against cephalosporinases. AC-1370 showed the unique antibacterial property that its activity was more potent in vivo than expected from in vitro and this was particularly true in P. aeruginosa infection tests; the therapeutic activity of AC-1370 was approximately two to six times more potent than that of cefoperazone, whereas its in vitro activity was lower than that of cefoperazone.