title: Ultrastructural changes in Tritrichomonas foetus after treatments with AlPcS4 and photodynamic therapy.
abstract: The Tritrichomonas foetus is an amitochondrial parasitic protist which causes bovine trichomoniasis, a major sexually transmitted disease in cattle. No effective drugs for this disease have been approved to this date. Photodynamic therapy (PDT) is an experimental treatment that shows great potential for treating bacteria, fungi, yeasts, and viruses. However, the cytotoxic effect of PDT on protozoan has been poorly studied. In this study, PDT with aluminum phthalocyanine tetrasulfonated (AlPcS4) photosensitizer was efficient in killing T. foetus. The mode of cell death in T. foetus after PDT was investigated by transmission electron microscopy. Morphological changes, such as membrane projections, nucleus fragmentation with peripheral masses of heterochromatin, endoplasmic reticulum proliferation, intense cytoplasmic vacuolization, fragmented axostyle-pelta complex, and internalized flagella could be observed. This is the first report to demonstrate cell death in T. foetus after PDT, and thus will open up new lines of investigation to develop new treatments for bovine trichomoniasis.
authors.affiliation: Laboratório de Biologia Celular e Tecidual, Instituto de Pesquisa e Desenvolvimento, Universidade do Vale do Paraíba, Av. Shishima Hifumi 2911, 12244-000 São José dos Campos, SP, Brasil. nsoares@univap.br
authors.forename: Newton Soares
authors.initials: NS
authors.lastname: da Silva
authors.forename: Claudia de Mello
authors.initials: Cde M
authors.lastname: Ribeiro
authors.forename: Aline Helena Araujo
authors.initials: AH
authors.lastname: Machado
authors.forename: Cristina
authors.initials: C
authors.lastname: Pacheco-Soares
mesh_terms: D000818:Animals; D007211:Indoles / Q000494:pharmacology*; D007834:Lasers; D009942:Organometallic Compounds / Q000494:pharmacology*; D010778:Photochemotherapy / Q000379:methods*; D011838:Radiation-Sensitizing Agents / Q000494:pharmacology*; D016835:Tritrichomonas foetus / Q000187:drug effects* / Q000528:radiation effects* / Q000648:ultrastructure
chemical_list: D007211:Indoles; D009942:Organometallic Compounds; D011838:Radiation-Sensitizing Agents; C048577:aluminum tetrasulfophthalocyanine