Endodontic retreatment patients with clinical symptoms have strong biofilm formation ability and high expression of virulence factors of E. faecalis

Abstract

Enterococcus faecalis has a high detection rate in root canals with failed endodontic treatment. The previous studies had shown the relationship between biofilm formation and expression of virulence factors in digestive disease. In this study, we want to find out the relationship between biofilm formation and expression of virulence factors, like enterococcus surface protein (esp), collagen-binding protein (ace), haemolysin activator(cylA), of E.faecalis recovered from root canals undergoing orthograde retreatment. Fifty clinical patients were recruited. All of them complained at least one of the following symptoms: spontaneous pain, pain of occlusion (apical shadow), sensitive to percussion, parulis and fistula. Most isolates successfully formed biofilms. After 24h of cultivation, the expression of ace, cylA, esp in the biofilm-positive groups were higher than that of biofilm- negative groups (P< 0.05). The expressions of esp and ace were higher than that of cylA in patients with pain of occlusion (P< 0.05). The results indicated patients with six clinical symptoms we studied had higher expression level of virulence factors than those without these symptoms. © 2012 The Hard Tissue Biology Network Association Printed in Japan, All rights reserved.