Cefsulodin, formerly named as SCE-129, is a cephalosporin with a spectrum of antibacterial activity against Staphylococcus aureus, Pseudomonas aeruginosa, and most other gram-positive cocci [1]. Cefsulodin shows little activity against other species of Acinetobacter spp., Pseudomonas, or members of the Enterobacteriaceae [1]. Cefsulodin is a β-lactam antibiotic that involved in lysing actively-growing E. coli by specifically binding to the intermembrane proteins, penicillin-binding proteins 1a and b, whose transglycosylase and transpeptidase activities are involved in cell elongation and septation [2].

Cefsulodin was active against P. aeruginos. Cefsulodin was active against penicillinase-producing strains of S. aureus. The MICs of cefsulodin for Pseudomonas aeruginosa and its mutants Pseudomonas aeruginosa PAO4089 were 0·78 and 12· mg/l [3]. Cefsulodin was active in minimum inhibitory concentrations (MICs) of 0.5 to 64 μg/ml. Cefsulodin was active against P. diminuta, P. maltophilia, P. paucimobilis, and P. pseudoalcaligenes with MICs of 1-32 μg/ml. Cefsulodin was not hydrolyzed by the β-lactamase induced in P. aeruginosa by growth in the presence of benzylpenicillin and was a poor substrate for β-lactamases from Enterobacter cloacae and Proteus morganii [4].

References:
[1] Barry A L, Jones R N, Thornsberry C.  Cefsulodin: antibacterial activity and tentative interpretive zone standards for the disk susceptibility test[J]. Antimicrobial agents and chemotherapy, 1981, 20(4): 525-529.
[2] Jacoby G H, Young K D.  Cell cycle-independent lysis of Escherichia coli by cefsulodin, an inhibitor of penicillin-binding proteins 1a and 1b[J]. Journal of bacteriology, 1991, 173(1): 1-5.
[3] Bryan L E, Kwan S, Godfrey A J.  Resistance of Pseudomonas aeruginosa mutants with altered control of chromosomal beta-lactamase to piperacillin, ceftazidime, and cefsulodin[J]. Antimicrobial agents and chemotherapy, 1984, 25(3): 382-384.
[4] King A, Shannon K, Phillips I.  In vitro antibacterial activity and susceptibility of cefsulodin, an antipseudomonal cephalosporin, to beta-lactamases[J]. Antimicrobial agents and chemotherapy, 1980, 17(2): 165-169.