| abstract |
A novel cephalosporin derivative of the formula: <IMAGE> [wherein X is hydrogen, hydroxyl, acyloxy, alkoxy, carbamoyloxy, quaternary ammonium or a group of the formula -SR1 (where R1 is a nitrogen-containing heterocyclic group)] or a pharmaceutically acceptable salt or ester thereof is found to have potent antibiotic activity against various bacteria, particularly against gram-negative bacteria such as Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, Proteus mirabilis, Proteus morganii, Proteus rettgeri and Citrobacter freundii. |