Used primarily as an antibiotic to treat infections caused by Gram-negative bacteria, especially multidrug-resistant strains. Commonly applied in topical formulations for skin, eye, and ear infections. Also used in combination with other antibiotics to enhance effectiveness against severe infections like pneumonia or urinary tract infections. Frequently included in selective culture media to isolate specific pathogens by inhibiting unwanted bacterial growth. Used in research settings to study bacterial cell membrane disruption due to its ability to target lipopolysaccharides in the outer membrane of Gram-negative bacteria.