Colistin sulphate is an:
## Antibiotic
1. *Polymyxin antibiotic*: Effective against certain Gram-negative bacteria.
2. *Veterinary use*: Commonly used in animal husbandry to treat bacterial infections.
## Applications
1. Animal feed additives (though usage has declined due to antibiotic resistance concerns)
2. Veterinary medicine (treatment of bacterial infections)
