Cytopathological changes associated with the experimental inoculation of Brucella Abortus in laboratory animal (cavia porcellus)

Abstract

Background: Brucellosis is a zoonotic disease caused by Brucella Abortus which is a gram negative facultative intracellular pathogen, affecting both humans and animals. Transmission of bacteria has usually been through occupational hazards as well as through oral route where it lodges in the mucosa, beneath the sub mucosa these bacteria are ingested by phagocytes. It has been observed that the disease induces hepatomegaly and measurable splenomegaly related to accelerated lymphohistiocytic cells inside the spleen with predominant increases in the share of splenic macrophages, but it may also produce other degenerative and necrotic changes in other vital organs and lymph nodes. The intracellular life of Brucella limits touch to the host innate and adaptive immune responses, protects the organism from the effects of some antibiotics, and drives the only features of pathology in infected hosts which is normally separated into three wonderful levels; the incubation, acute and the extension phase. Methods and materials: The study comprised of 3 male, 3 female and 3 control animals. Among these, the male and female animals were inoculated with doses of inoculum 1 × 108 CFU, 3 × 107 CFU and 1 × 107 CFU respectively. The reason of different doses was meant to check out extent of pathological lesions in the target laboratory animal. The bacterial strain isolate was obtained from the spleens of inoculated mice cultured in broth C (BBLTM, USA). Results: Grossly, lymph nodes and mesenteric network were severely hyperemic and congested while, heart, liver, spleen, kidneys, lungs and heart were also congested, enlarged with pale mucous fluid present all over the dorsal surface. Intestines were swollen while strauss reaction and orchitis and anemic uterus were observed in male and female animals respectively. Microscopically, sloughing of germinal epithelium of seminiferous tubules, and infiltration of inflammatory cells were observed in epidydimus. Emphysematous alveoli and thickened alveolar walls in lungs, increased bowman's space in kidneys, fragmentation in heart muscle fibers, lymphohistiocytic cells in spleen and vacuolation changes were observed in these cells. Conclusion: The bacterium also induces specific gross and microscopic changes in all body organs apart from liver and spleen which were considered as the main predilection site of the bacteria.