Effects of three benzimidazoles on growth, general morphology and ultrastructure ofTritrichomonas foetus

Abstract

Tritrichomonas foetus is a venereal pathogen of cattle, which causes infertility, early embryonic death or abortion. In order to evaluate the potential trichomonicidal activity of benzimidazoles, the effects of thiabendazole, mebendazole and albendazole were analyzed on the multiplication, general morphology and ultrastructure of T. foetus. It was found that mebendazole presented the highest IC(50%) (2.3 microM), when compared with albendazole (IC(50%)=9.4 microM) and thiabendazole (IC(50%)=142.6 microM), and that such effects were irreversible. Concerning microscopic analysis, thiabendazole- and mebendazole-treated cells presented increased volume, internalization of the flagella, disruption or multiplication of the nucleus, multiple organelles and cytoplasmic vacuolization. Albendazole-treated cells exhibited slight alterations, because the parasite became slightly rounded, its flagella were not internalized but the cytoplasm was vacuolated. Mebendazole was indeed highly effective as an in vitro trichomonicidal agent, and this might open up new possibilities for the use of mebendazole in the therapy of bovine trichomoniasis.

Partial sequence of the beta-tubulin of Histomonas meleagridis and the activity of benzimidazoles against H. meleagridis in vitro

“…However, a susceptibility could not be shown in the in vitro test, even though the concentrations tested were by far higher than the concentrations found effective in T. vaginalis and T. foetus by and Carvalho and Gadelha (2007). However, our results are in full agreement with the findings of Hu and McDougald (2004) and Callait et al (2002), so the different results for T. vaginalis and T. foetus on one side and for H. meleagridis on the other side will require further investigation.…”

“…In agreement with their beta-tubulin sequences, T. vaginalis ) and T. foetus (Carvalho and Gadelha 2007) were shown to be susceptible to benzimidazoles in vitro. Table 1 shows the concentrations inhibiting growth to 50% of control levels (IC 50 ) in vitro of four benzimidazoles that are licensed for use in food-producing animals and of nocodazole, which was found to be the most potent benzimidazole tested.…”

“…PCR was done using Ready-To-Go™ PCR beads (GE Healthcare) according to the manufacturer's instructions. Briefly, a reaction sample contained 1.5 U Taq polymerase, 10 mM Tris-HCl pH 9.0, 50 mM KCl, 1.5 mM MgCl2, 200 μM of each deoxynucleoside triphosphate, stabilizers, 20 pmol of each Table 1 Inhibitory concentration 50 (IC 50 ) of benzimidazoles for T. vaginalis and T. foetus in vitro according to and Carvalho and Gadelha (2007) n. t. not tested primer, 1 μl DNA, and nuclease-free water up to 25 μl. After initial denaturation for 1 min at 95°C, amplification was conducted for 36 cycles and consisted of 1-min denaturation at 95°C, 1-min annealing at 55°C, and 1-min extension at 72°C.…”

Lycorine induces cell death in the amitochondriate parasite, Trichomonas vaginalis, via an alternative non-apoptotic death pathway

“…5B-F). These vacuoles varied in morphology and size and presented internal membranous structures, as previously observed in mebendazole-treated parasites (Carvalho and Gadelha, 2007). The hydrogenosomes were found to be randomly distributed within parasite cells after lycorine (1) treatment, and exhibited altered size and shape.…”

Intestinal Tritrichomonas foetus infection in cats in Switzerland detected by in vitro cultivation and PCR

“…Compared to the T. foetus reference strain 30924, the cat isolate did not show the typical elongated, slightly pear-shaped form but was rounded and full-bodied. Such changes in morphology have been described by various authors as signs of stress caused by variations in temperature or other physical influences or as effects of treatment with various drugs (Granger et al 2000;da Silva et al 2007;Carvalho and Gadelha 2007).…”