polymyksineja

Polymyksineja is a group of basic polypeptides that act as antibiotics. They are primarily produced by the bacterium Paenibacillus polymyxa. The polymyxin family includes compounds like polymyxin B and polymyxin E (colistin). These antibiotics function by disrupting the cell membrane of susceptible bacteria, particularly Gram-negative bacteria. They interact with the lipopolysaccharide (LPS) component of the Gram-negative outer membrane, leading to increased permeability and cell death.

Polymyxins are generally considered a last-resort antibiotic due to their potential for nephrotoxicity and neurotoxicity. Their use has been limited for many years, but with the rise of multidrug-resistant Gram-negative infections, polymyxins, particularly colistin, have seen a resurgence in clinical use. They are often administered intravenously or topically. In some regions, polymyxin B is used in ophthalmic preparations and in topical antibiotic combinations. The development of resistance to polymyxins is a growing concern, often mediated by modifications to the bacterial LPS structure. Research continues to explore new polymyxin derivatives and strategies to overcome resistance mechanisms.