Endotoxic activities of lipopolysaccharides of microorganisms isolated from an infected root canal in Macaca cynomolgus

Abstract

– Lipopolysaccharides (LPS) prepared from a strain of Bacteroides oralis, a strain of Fusobacterium necrophorum, and a strain of F. nucleatum, all isolated from an infected root canal in monkey (Macaca cynomolgus), were examined for endotoxic activities using primary skin reactions in rabbits and induction of leukocyte chemotaxis in rats. LPS of B. oralis showed considerably lower ability to cause skin inflammation than LPS of the fusobacteria. However, the leukotactic effect of the LPS preparations as determined by the wound chamber method in rats was approximately of the same proportion. In both tests the reactions were compared with those of commercial LPS of Salmonella typhi. This study shows that endotoxic LPS can be isolated from oral Gram‐negative bacteria, which have infected the root canal. Therefore LPS. may play a role in the development and maintenance of chronic inflammation of the periapical tissues.

Dentin Enhances the Antibacterial Effect of Mineral Trioxide Aggregate and Bioaggregate

“…Root-end filling provides apical sealing to prevent penetration of bacteria, if present, and diffusion of bacterial by-products such as lipopolysaccharide (2) from the root canal to the periapical tissues. Therefore, the key characteristics of a root-end filling material are quality of the seal, biocompatibility, and antimicrobial effect (3).…”

Biological effects of a root conditioning agent for dentin surface modificationin vitro

“…A polysaccharide moiety is a potent antigen that can elicit antibody formation even in submicrogram concentrations [35]. Anaerobic Gram-negative bacteria have been frequently isolated from root canals of endodontically treated teeth; consequently, their endotoxins may affect the periapical tissues and exert a role in the pathogenesis of inflammatory lesions of pulpal origin [36]. The experimental gel used in this study was effective for antimicrobial activity and removal of LPS.…”

Dental Pulp Response to Bacterial Cell Wall Material

“…LPS were prepared by the phenol/water extraction method and purified by the use of DNAse and RNAse treatment and ultra-centrifugation, as described by Dahlen and Hofstad (1977). CW from L. casei was prepared by expressing (Edebo, 1960) and centrifugation, as described previously (Dahlen et al, 1982).…”