Effect of Lactobacillus Casei on Hematological and Histopathological Factors in Rats Infected with Salmonella typhimurium

Introduction: Salmonella typhimurium is one of the most important causes of gastrointestinal diseases in humans and animals. Probiotics inhibit pathogens, such as Salmonella Typhimurium by producing antimicrobial compounds. Therefore, this study assessed the protective effect of Lactobacillus casei on hematological factors in rats infected with Salmonella typhimurium with the possibility of salmonellosis treatment.    Materials & Methods: Totally, 32 male rats (150±20 g) were purchased and randomly divided into four groups, namely injection control group (A), infected with Salmonella typhimurium (1.5×108 CFU/ml) (B), treated with Lactobacillus casei (C), and infected with Salmonella typhimurium and treated with Lactobacillus casei (D). After the treatment, the blood sample was taken in order to evaluate blood parameters. In addition, a part of the liver tissue was separated and stained with hematoxylin-eosin. The other part was homogenized and cultured based on pour plate method. Subsequently, the number of pathogen colonies was counted in tissues.   Findings: According to the results, the number of lymphocytes, monocytes, and basophiles had increased significantly in group B than those in the control group. Histopathological changes and cell death were evident in the livers of the group B. However; the liver tissues of other groups had normal appearance. In addition, the growth of Salmonella Typhimurium bacteria was significantly lower in group D, compared to group B.   Discussion & Conclusions: The results showed that Lactobacillus casei could overcome Salmonella Typhimurium without any adverse effects on hematological and histopathological factors and it could prevent the development of disease to some extent.