Polymyxin B use does not ensure endotoxin-free solution

Polymyxin B use does not ensure endotoxin-free solution.

Polymyxin B is often added to in vitro samples to 'ensure' that endotoxin activity is removed. We present data, from the standard rabbit pyrogen test and the Limulus amebocyte lysate assay, that polymyxin B bound to a gel support will bind some, but not all, endotoxin. These data, in conjunction with previously published data by Morrison and Curry (1979), indicate that those studies that have r...

Inactivation of endotoxin by polymyxin B.

The limulus gelation assay was utilized to investigate endotoxin inactivation by a number of antibiotics in vitro. Endotoxin activity was sharply reduced by polymyxin B and sodium colistimethate. The effect of the polymyxin was not significantly inhibited by 0.001 M calcium or 90% serum. Crude endotoxins from a variety of aerobic gram-negative bacteria, including several not previously studied,...

Prevention by polymyxin B of endotoxin lethality in mice.

Certain of the cyclic cationic polypeptide antibiotics, polymyxin B, colistin, and tyrocidine, prevent the lethal effect of endotoxin for chick embryos when admixed with the toxin prior to intravenous injection. In this system, 25 ,ug of polymyxin B sulfate prevented the toxicity of 0.217 ,ug (241 LD50) of Escherichia coli endotoxin; an antibiotic-endotoxin weight ratio of 115:1. (D. Rifkind an...

PMX-622 (polymyxin B-dextran 70) does not alter in vitro activities of 11 antimicrobial agents.

Because of its capacity to neutralize the lethality of gram-negative bacterial endotoxic lipopolysaccharides, PMX-622 (polymyxin B bound to dextran 70) is being developed for possible adjunctive therapy of gram-negative sepsis. In this study, it was determined that the in vitro antimicrobial activity of PMX-622 was minimal and that it does not interfere with the in vitro antimicrobial activity ...

Genetic discrimination: why Bragdon does not ensure protection.