Histological and Physiological Evaluation of Salmonella Spp. Pathogenicity Experimentally Dosed in Male Albino Mice
Authors: Rasheed Dr. Khulood Naji , Ibrahim Yahya Waheeb , Atiyea Dr. Qanat Mahmood 
Published: August 2024

The research aimed to isolate and diagnose the serological strains of Salmonella spp. that cause typhoid fever, as well as those that cause intestinal inflammations, and to study their histological pathogenesis after experimentally dosed in immunosuppressed male albino mice. The research included 180 blood and stool samples from people with typhoid fever, and 20 samples from people with diarrhea, as well as 30 samples representing the control group. The bacteriological results showed that 26 patients were diagnosed with S. typhi out of 180 patients with typhoid fever, representing 14.4%, and 5 patients were diagnosed with S. typhimurium out of 20 patients with diarrhea, representing 25%. The results of the study showed an increase in the levels of liver enzymes, as the average concentration of the ALT enzyme for the category of patients infected with typhoid, with a recent and confirmed infection with S. typhi, reached 11.283 international units/liter, and the average concentration of the AST enzyme for the same category reached 20.1 international units/liter, compared to the control group. 48 male laboratory mice were used and distributed into 4 groups of 12 mice per group. The first group was the control group that was dosed with physiological solution in an volume of 0.2 ml. The second group was dosed with a suspension of S. typhi bacteria in a volume of 0.2 ml and a concentration of 1×108 colonies/ml. The third group was dosed for a week with the immunosuppressant cyclosporine before and after the experimental infection with a suspension of S. typhi bacteria in a volume of 0.2 ml and a concentration of 1×108 colony/ml. The fourth group was dosed with a suspension of S. typhimurium bacteria in a volume of 0.2 ml and a concentration of 1×107 colony/ml. The mice were dissected one week, two weeks and three weeks after the experimental infection, at a rate of 3 mice per week from each group. The blood was collected and the liver was removed from each mouse. The results showed a slight increase in the ALT enzyme average concentration for the group of mice treated with the immunosuppressant cyclosporine and dosed with S. typhi, reaching 18.57 IU/L, while the group of mice dosed with S. typhimurium was within the limits of the control group and reached 12.24 IU/L. The AST enzyme concentration rate in the control group was 15.136 IU/L, and for the group of mice treated with the immunosuppressant cyclosporine and dosed with S. typhi, it reached 24.74 IU/L, while the concentration for the group of mice dosed with S. typhimurium reached 21.76 IU/L. As for the histological study, the results of the microscopic examination showed the occurrence of many histological lesions in the liver, represented by severe degeneration and acute necrosis, with hypertrophy and sometimes hyperplasia in the hepatocytes, and the loss of chromatin in the nuclei of a number of them, with thickening of the nuclear envelope and sometimes thickening of the nuclei, as well as vacuolation of the cytoplasm in other hepatocytes, with an increase in the number and size of Kupffer cells in the blood sinusoids, which varied in their appearance between narrowed, dilated and congested with blood. It was found that these pathological lesions were more severe in the group of mice treated with the immunosuppressant cyclosporine and dosed with S. typhi.