Some immunological responses in rats injected with prepared bacterin toxoid of local methicillin resistant Staphylococcus aureus

This study was aimed to prepare bacterin toxoid from local isolate of methicillin resistant Staphylococcus aureus (MRSA) isolated from bovine mastitis in Basrah province. Isolated MRSA was detected and confirmed using polymerase chain reaction. Then inactivated bacterin toxoid was prepared. A total of 45 male albino rats were used in 3 mainly groups to assess the bacterin toxoid. For immunological response, the concentrations of IL-4, CD4+, and CD8+ T-cells were estimated using enzyme linked immunosorbent assay. The results showed increase in the concentrations of IL-4, CD4+ and CD8+ T-cells in vaccinated group comparing with non-vaccinated control group. Increasing concentrations of IL-4 enhance humoral immune response by stimulation of Th2 that effect directly on B-cells differentiating them to plasma cells responsible for production of specific antibodies against MRSA. Increased CD4+T-cells also enhance humoral immune response as a result of interaction between them and antigen-presenting cells which presented major histocompatibility complex (MHC) type II on their surface, while increased CD8+T-cells enhance cellular immune response as a result of interaction between them and somatic effected cells presented MHC type I on their surface leading to differentiation them to Cytotoxic T lymphocytes (CTLs) responsible for the killing of effected cells. It was concluded that locally prepared bacterin toxoid proved their efficacy to stimulate both humoral and cell mediated immunity in rats as an experimental animal model.