What is Colistin sulfate ? Fosfomycin Calcium has broad antibacterial activity against both Gram-positive and Gram-negative pathogens,with very useful activity against E. faecails, E. coil, and various Gram-negative like Cirtobacter and Proteus. Given activity in a low pH milieu, and predominant excretion in activity from into the urine, fosfomycin was found to use for the prophylaxis and treatment of urinary tract infectious caused by these uropathogens Colistin Sulfate CAS 1264-72-8 is used to treat intestinal infections caused by Gram negative bacilli (E. coli, etc.), and is also effective against Pseudomonas aeruginosa infections (sepsis, urinary tract infections, burns or trauma, wound infections). Colistin Sulfate is an antibiotic of basic polypetides composed. Colistin Sulfate has strong antibiotic effect against intestinal diseases caused by gram-negative bacilli. Colistin Sulfate is used as feed additive.