Immunological effects of Citrobacter freundii cell free culture in rabbit

Abstract

Citrobacter freundii is usually considered a commensal species of the human gut, although some isolates have acquired specific virulence traits that enable them to cause diarrhea.C. freundii cell free culture (CFC) antigen was used in this study . Three rabbits of 2-3months age(Newzalent , Orcyctylagus cunninculus)were immunized by CFC in addition to complete Freunds adjuvant .After one month immunization period some of systemic immune response parameter (cellular and humoral)were studies and compared with control animal. The results of test animals showed that CFC antigen lead to stimulate systemic cellular immune response which determined by using E-rosette test , (nitroblue tetrazolium) reduction test (NBT) , leucocyte migration inhibitory factors (LIF) test. The results were appeared that higher number of E-rosette (0.45±0.02) compared with control animals (0.28± 0.01), also there was increasing in the percentage of neutrophils phagocytic activity (0.59±0.03 ) compared with control animals(0.48±0.02). The LIF in test animals was significantly produced in contrast to the control animals which not produce these factors. The humoral immune response was studied. The results of hemagglutination test was appeared higher titer of test animals (128 ±0 )compared with control group titer (1) and this true for immunoglobulin, complement and total protein concentrations. The concentration of IgM (424.1±9.2)mg/dl , IgG concentration was (2365.3±34.2) mg/dl and IgA concentration (494.4±0) mg/dl. The concentration of C3 was (241.0±5.4) mg/dl , C4 concentration was (55.4±2.4) mg/dl and total protein concentration (9.5±0.34) mg/dl. All these results for test animals were higher significant at (P<0.05) compared with control animals. We conclude that CFC antigen of C. freundii stimulate humoral immune response in rabbits