Polymyxin B

Description

• General description: Polymyxin B (PMB) is a cyclic cationic lipopeptide antibiotic originally produced by soil bacterium Bacillus polymyxa. Polymyxin B binds specifically to gram negative bacteria by interacting with the anionic lipopolysaccharide (LPS, or endotoxin). Polymyxin B interferes with the outer membrane normal function causing leakage and enhanced uptake of the antibiotic.Polymyxin B has several applications:It is used to neutralize LPS contamination in vitro and in vivo. Its neutralizing effect is dose-dependent. In vitro experiments showed that PMB inhibits a septic shock by endotoxin inactivation. Cell cultures can be treated with PMB (100U/mL) to avoid early contaminations. PMB is considered a broad spectrum antibiotic and is used to treat infections caused by bacteria resistant to a combination of Penicillin and Streptomycin. PMB is also used as negative and positive control in minimum microbicidal concentration (MIC) assay. Working concentration:The suggested concentration of PMB in cell culture mediums is 100U/mL. Therefore, it is recommended to dilute PMB ready made solution 1:1000.