Cefotaxime (HR 756) a new cephalosporin with exceptional broad-spectrum activity in vitro

HR 756 is a semisyntbetic cephalosporin which is structurally similar to cefuroxime. We have tested it in parallel with cefuroxime, cefoxitin and cephalothin against 431 clinically isolated bacterial strains. Against Staphylococcus aureus and group A and B streptococci, there was little to choose between the four compounds. HR 756 was extremely active, however, against Gram-negative bacteria. It was 50 to 100 times more active than any of the other three compounds against all cephalcsporin-sensitive strains, and 100 to 1000 times more active than cefuroxime and cefoxitin against cephalosporin-resistant species. In addition, HR 756 was four times as active as carbcnicillin against Pseudomonas aeruginosa strains. From these properties it seems that HR 756 represents a major advance in cephalosporin antibiotics, and it appears possible that it would be clinically effective in very much smaller doses than have hitherto been used for this group of drugs.