Giardia lamblia attachment to biological and inert substrates.

Analysis of the attachment basis of Giardia lamblia 1/Portland strain trophozoites to confluent MDCK (Madin Darby Canine Kidney) cell monolayers and type I collagen films, demonstrated, by the use of light and electron microscopy, that the ventral disk as well as the ventrolateral border are the structures involved in the substrate adhesion. Furthermore, we noticed that trophozoite attachment is more effective to collagen than to the apical surface of the epithelium. We described, for the first time, a rounded shape structure evaginated from the naked area that seems to be the ventral disk contact site between the trophozoite and the substrate. This structure has also been observed when the trophozoite is attached to coverslip glass or among trophozoites in close contact.