Trichomonas tenax

Of the three parasites in the genus Trichomonas, T. tenax is the smallest, measuring only 5-14 µm long and 6-9 µm wide; specimens can be identified by their long axostyles and tails, 4 anterior flagella, and by the recurrent flagellum that raises an undulating membrane which is two thirds the length of the body. This undulating membrane may appear like small legs. It may occasionally appear larger, allowing it to be confused with Trichomonas vaginalis due to similar morphology. In such cases, the presence of an oral or vaginal parasite should be confirmed, due to the ease with which the parasite can be transmitted through direct contact of mucous membranes.

In infected hosts, the parasite can typically be found among dental calculus, as well as within the tonsillar crypts, which will often become purulent during the course of infection. T. tenax may also be involved in the degradation of periodontal tissue through the secretion of substances such as alkaline phosphatases and the fibronectin cathepsine.[9] T. tenax is classified as a parasite due to the manner in which it causes damage to host tissues; its behavior when in contact with target cells is similar to the closely related and likewise parasitic T. vaginalis.[10] It has no cysts and is transmitted directly from its vegetative form.

Owing to the morphological similarity between T. tenax and other trichomonad spp., examination of a greater number of organisms is necessary to establish a reliable diagnosis than is easily obtained from the patient's mouth. Chen et al. (1997) studied the efficacy of different culture media and conditions on T. tenax reproduction in vitro. T. tenax reproduced better in LES medium, pH value between 5.80 and 7.00 with cultivation temperature of 35 °C than other media with pH 5.40 and cultivation temperature of 37 °C.[11] Normal, healthy human saliva is slightly alkaline at pH 7.40. Whitening products have a mean pH of 8.22 with a range (5.09-11.13). Whitening toothpastes have a mean pH of 6.83 with a range (4.22-8.35). Mouthwashes also vary greatly in pH from pH 4.40 to 6.80. Mouth rinsing after an acidic challenge increased salivary pH. The tested mouthwashes raised pH higher than water. Mouthwashes with a neutralizing effect can potentially reduce tooth erosion from acid exposure.[12] Essentially the human mouth is an optimum habitat for this organism and any pH level alteration needed to stunt the reproductive rate significantly would require a duration of time that would cause greater damage to the tooth enamel than to T. tenax. Regular oral hygiene and dental visits to remove dental plaque is currently the best solution to deal with this protozoan.

Dimasuay, Kris Genelyn B.; Rivera, Windell L.; Fontanilla, Dr. Ian Kendrich C. (April 2014). "First report of Trichomonas tenax infections in the Philippines". Parasitology International. 63 (2): 400–402. doi:10.1016/j.parint.2013.12.015. PMID 24406842.