Adherence to and penetration through endothelial cells by oral treponemes

Oral spirochetes were so-incubated with monolayers of endothelial cells see ded into multiwell plates or onto haters mounted in plastic chambers. Attac hment was assessed using an enzyme-linked immunosorbent assay and scanning electron microscopy. Invasiveness was determined by monitoring media beneat h filters within chambers for spirochetes using darkfield microscopy. Trans mission electron microscopy was used to estimate intercellular and intracel lular passage of spirochetes through monolayers. All tested treponemes atta ched to monolayers in a dose- and time- dependent manner, except Treponema phagedenis. A few treponemes were observed within host cell cytoplasm. Unid entified spirochetes obtained from dental plaque were also invasive. Result s indicate that oral spirochetes possess virulence-associated characteristi cs shared with pathogenic spirochetes. Further studies should examine the p ossibility that invasive spirochetes could disseminate from within affected gingiva.