[In vitro release of lipopolysaccharide in Escherichia coli by addition of antiseptic and disinfectant products].

Release of lipopolysaccharide (LPS) by E. coli following addition of antiseptics and disinfectants was investigated using the Limulus test. The five following compounds were studied: glutaraldehyde (cidex 2%), chlorhexidine 0.05%, povidone iodine 5%, aqueous formol 37%, and cetavlon 20%. These compounds were used in concentrations 2 to 4 times greater than the previously determined minimal inhibitory concentrations. LPS concentration falls sharply following addition of glutaraldehyde (cidex) to a suspension of E. coli (approximately 10(6)/ml). Released LPS is completely inhibited by formol and cetavlon. In contrast, high levels of LPS persist in the presence of chlorhexidine and povidone iodine. These results illustrate the need for thoroughly and generously washing all non-autoclavable equipment exposed to these chemical agents.