الفهرس 
Aim of workOnly 14 pages are availabe for public view
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Abstract
Toxoplasmosis, caused by Toxoplasma gondii, is the most prevalent parasitic zoonotic disease infecting almost all warm-blooded animals, including humans, and about 2 billion people in the world (Mose et al., 2019). Infections are obtained by ingestion of undercooked or raw meat containing viable tissue cysts, or by ingesting food or water contaminated with T. gondii oocysts (Dubey, 2008). Vertical transmission is also possible across the placenta (Robert-Gangneux et al., 2012).
There are limited effective therapeutic options for toxoplasmosis with no optimal effective treatment for chronic toxoplasmosis due to poor penetration into the brain and potential side effects which necessitate the discovery of effective and safe therapeutics (El-Kady et al., 2022).
One of the main characteristics of probiotics is their ability to stimulate and modulate the immune response. It can stimulate local and systemic immunity, in addition to the activation of macrophages at sites distant from the intestine. Activated macrophages limit the replication of intracellular protozoa, such as Toxoplasma gondii, through the production of nitric oxide (Salas-Lais et al., 2020).
In the present study, we aimed to evaluate and compare the prophylactic and therapeutic effects of probiotics on toxoplasmosisinfected mice. The evaluation was done by parasitological, histopathological, serological and immunohistochemical studies.
The current study was performed on 70 Swiss albino mice, 6-8 weeks old, weighing 20-25 grams. Mice were obtained from Theodore Bilharz Research Institute (TBRI), Giza, Egypt and kept under standard housing conditions in the animal house of TBRI, with controlled temperature and humidity conditions (25 °C; 70%). The mice were divided into seven groups as follows:- Negative control group (GI): non-infected, non-treated. Positive control group (GII): infected non-treated. Probiotic prophylactic infected group (GIII): Mice received probiotics as prophylaxis, then were infected by T. gondii cysts. Probiotic-treated infected group (GIV): Mice were infected and then treated with probiotics. Spiramycin treated infected group (GV): Mice were infected and then treated with spiramycin. Probiotic-treated group (G VI): probiotic-treated non-infected group. Spiramycin treated group (GVII): spiramycin treated non-infected group.
In this study, T. gondii cysts were counted in the brain tissues of the infected mice that were sacrificed at day 60 post-infection. The degree of inflammation, hemorrhage and edema in the brain, heart and eye tissues were evaluated. Also, CD3 and Caspase3 expression in these tissues were evaluated. Blood samples were taken for estimation of serum level of IL10 and IFN-γ in sera of all mice by ELISA.
Results of this study demonstrated that probiotics could reduce the brain cyst count of mice chronically infected with T. gondii and that the administration of probiotics as prophylaxis was more effective than administration as a treatment after infection. The lowest number of cyst counts in brain tissue was in the spiramyin-treated infected group with a reduction percentage 70.35%. Followed by the probiotic prophylactic infected group with a reduction percentage 59.3%. Then probiotic treated infected group with a reduction percentage 47.5%.
In this study, the value of IFN-γ was decreased with treatment while the value of IL10 was increased with treatment as probiotics suppressed the inflammatory reactions by increasing the IL-10 (anti-inflammatory factor) and decreasing the activities of IFN-γ (proinflammatory factor). The highest reduction of IFN-γ was in GV (8.97 ± 0.44), followed by GIII (12.78 ± 1.06), then GIV (18.69 ± 0.89). On the other side, the highest value of IL10 was in GV (137.84 ± 1.76), followed by GIII (97.53 ± 3.5), then GIV (79.12 ± 1.8).