Cysteine proteases and acid phosphatases contribute to Tetrahymena spp. pathogenicity in guppies, Poecilia reticulata Academic Article uri icon


  • Systemic tetrahymenosis caused by the protozoan parasite Tetrahymena spp. is a serious problem in guppy (Poecilia reticulata) farms worldwide. There is no therapeutic solution for the systemic form of this disease. Guppies severely infected with Tetrahymena spp. were imported by a commercial ornamental fish farm and brought to our laboratory. Tetrahymena sp.(Tet-NI) was isolated and in vitro cultured. Isolates maintained in culture for different time periods (as reflected by different numbers of passages in culture) were analyzed—Tet-NI 1, 4, 5 and 6, with Tet-NI 1 being cultured for the longest period (about 15 months, 54 passages) and Tet-NI 6 for the shortest (2.5 months, 10 passages). Controlled internal infection was successfully achieved by IP injection with most isolates, except for Tet-NI 1 which produced no infection. The isolate Tet-NI 6 induced the highest infection rates in …

publication date

  • January 1, 2009