Implantation of bacteria from human pulpal necrosis and translocation fromroot canals in gnotobiotic mice

The aim of this study was to determine whether microorganisms recovered fro m infected human root canals were able to survive and translocate to a loca l lymph node when experimentally inoculated into the root canal system of g erm-free mice. The microorganisms isolated from two patients with pulpal ne crosis were inoculated in two groups of experimental animals; group I (Geme lla morbillorum) and group II (Bifidobacterium adolescentis, Fusobacterium nucleatum, and Clostridium butyricum). G. morbillorum showed the highest fr equency of colonization and translocation to the draining lymph node. In gr oup II only F. nucleatum and C. butyricum colonized and translocated when i noculated in tri-association. When the bacteria from group II were inoculat ed in monoinfection all three species colonized the root canal of germ-free mice and translocated to the draining lymph node, but with different frequ encies. We conclude that selective mechanisms occur in which some bacterial species are fit to survive, multiply, and translocate in the germ-free mou se model.