Trichomonas tenax: ultrastructure of giant forms.

Trichomonas tenax is a parasitic flagellate of the human mouth. The morphology and the ultrastructure of the protozoan are identical to those of other trichomonads. Giant forms suddenly appeared in a strain maintained in culture for two years. The structure and the ultrastructure of these abnormal forms were studied at the light and electron microscope level. Several nuclei, groups of flagella, undulating membranes and Golgi complexes were observed. The significance of these forms is still unknown.

Immunohistochemical localization of fibronectin-like protein on the cell surface of the oral flagelatte Trichomonas tenax.

A protein immunologically related to fibronectin was demonstrated on the oral flagellate Trichomonas tenax. Two strains of T. tenax were used, the first freshly taken from ulcerative gingivitis and the second maintained in culture for 2 years. Initial investigations were made by established immunofluorescence staining procedures. Cells of the protozoa gave a positive fluorescence with anti-fibronectin anti-serum, while the controls were negative. Subsequently, indirect immunostaining procedures for electron microscopy were performed using the peroxidase procedure. Peroxidase deposits were detected on the outer layer of the cell membrane. Particularly intense labelling was localized in the contact areas between bacteria and protozoa, and sometimes within the marginal lamina of the undulating membrane. This fibronectin-like protein could potentially play an important role in the adhesion of Trichomonas tenax to gingival cells, connective tissue and in the phagocytosis of bacteria. The attachment of protozoa to gingival substrates could be the first step in the breakdown of periodontal tissues.

[Supplemental data to the ultrastructural study of Trichomonas tenax. Intra-cellular distribution of acid phosphatase]. / Données complémentaires ä l'étude ultrastructurale de Trichomonas tenax. Localisation intra-cellulaire de la phosphatase acide.

In scanning electron microscopy, the flagella come out from the cellular body following different configurations: either separately or in groups. The undulating membrane lasted up to 2/3 of the cell body: at its end the recurrent flagella seems to penetrate again into the cell. The costa starts from the cinetosome of the recurrent flagella: the two parabasal filaments start from two different cinetosomes and follow the costa for a small distance. The nucleus is surrounded by a membrane which is not always visible. The axostyle has a cylindrical shape in the posterior two thirds of the cell. Bacteria at different stages of phagocytosis have been observed. The acid phosphatase is localized in the saccules and vesicles of the Golgi apparatus, in the lysosomes and phagolysosomes and in the terminal lamina of the undulating membrane.

[Study of an oral protozoan Trichomonas tenax using scanning and transmission electron microscopy]. / Etude du protozoaire buccal Trichomonas tenax en microscopie électronique à balayage et en transmission.

The study with scanning and transmission electron microscopy of Trichomonas tenax gave morphological information on this protozoon. The oval-shaped cell body showed at the anterior pole four free flagella and a trailing flagellum which had an undulating membrane. The axostyle which consisted of microtubules and produced the cellular rigidity emerged at the posterior pole. An ovoid nucleus and a well-developed Golgi apparatus were located at the anterior pole. At the latter, a pelta consisting of horizontal microtubulus surrounding the kinetoplats from which started the flagella was also found. No mitochondria were observed: they were replaced by chromatin granules or hydrogenosomes. Numerous vacuoles and developing vesicles were found in the cytoplasm. Phagocytized bacteria were in an advanced stage of lysis. Others seemed intact showing even division phases.