“…Furthermore, immunohistochemical techniques have shown that P. gingivalis is localized beneath T. denticola in human subgingival plaque, while in deeper subgingival plaque their coexistence has been observed (Kigure et al, 1995). These various observations have been reproduced in dual-species biofilm experiments, which show that P. gingivalis acts as an initial colonizer of the substratum, with subsequent incorporation of T. denticola (Yamada et al, 2005). Interactions between these bacteria have been suggested to be mediated by P. gingivalis fimbriae recognizing dentilisin (Hashimoto et al, 2003) or by gingipains (Ito et al, 2010), and to involve the major surface protein (Msp) of T. denticola (Vesey & Kuramitsu, 2004;Rosen et al, 2008).…”