Fusobacterium Nucleatum Adheres To And Invades Epithelial Cells

Bacteria are etiologic agents of periodontal diseasesAdhesion and invasion are important aspects of bacterial virulence factors. Adhesion is the initial step for colonization.And invasion allows the bacteria not only to evade the host immune defence but also to spread into deeper tissues. We investigated the abilities of F. nucleatum to adhere to and invade epithelial cell.In vitro model,we used KB cells in place of human gingival epithelial cells(HGEC). P. gingivalis and two kinds of F.nucleatum were examined for their ability to adhere to and invade epithelial cells.Bacteria were added into KB cells.(l)For ail bacteria adhesion and invasion assays, the incubation was continued for 2hours.(2)For two-kind F. nucleatum, adhesion and invasion assays were carried out when the incubation was continued forl/2hr, 1hr, 2hr, 3hr, 4hr.The invasion level was determined by using the antibiotic protection assay. All experiments were performed in duplicated and repeated three times.We used one—way AVONA analysis to study the bacterial abilities to adhere to and invade epithelial cells. (1) P. gingivalis ATCC33277 wasincluded as a positive control. Two-kind Enucleatum could adhere to and invade KB cells.Comparable to P. gingivalis ATCC 33277,the adhesion and invasion levels of Enucleatum WCD05 ~1 (clinical isolate) were higher ,and those of Enucleatum ATCC 10953 were lower. (2)With the increasing incubation time, the adhesion and invasion levels of both Enucleatum were raised. Moreover, the interlized Enucleatum were still alive in KB cells at lest duing the early hours after invasion.(3) Between different strains,the abilities of Enucleatum to adhere to and invade epithelial cells have significant differences.When the adhesion and invasion levels reached maximum, those of Enucleatum WCD05-1 were about 3.7 times and 3.3 times as those of Enucleatum ATCC 10953 correspondingly.These results indicate that E nucleatum can adhere to and invade epithelial cells. Between different strains,the abilities of Enucleatum to adhere to and invade epithelial cells have significant differences.Those of Enucleatum clinical isolate (Enucleatum WCD05-1 ) are greater than those of the type stxa.in(EnucleatumATCC 10953).