5-Thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid, 7-[[(2S)-(2-amino-4-thiazolyl)(formylamino)acetyl]amino]-8-oxo-3-[(1,2,3-thiadiazol-5-ylthio)methyl]-, (6R,7R)- (9CI)

Cgp 31523A is a new aminothiazolyl cephalosporin. CGP 31523A inhibited E. coli, K. pneumoniae, P. mirabilis, C. diversus, K. oxytoca, P. stuartii, Salmonella and Shigella at less than or equal to 0.25 micrograms/ml. It was equal or 2-fold more active than cefotaxime and ceftazidime, and 4-fold more active than imipenem against these organisms.