Comparative experimental study of Brucella melitensis and its lipopolysaccharide in mouse model infected via subcutaneous route of exposure. (March 2018)

• Record Type: Journal Article
• Authors: Osman, Abdinasir Yusuf; Saharee, Abdul Aziz; Jesse, Faez Firdaus; Kadir, Arifah Abdul
• Is Part Of: Microbial pathogenesis. Volume 116(2018)
• Page Start: 318
• Page End: 327
• Publication Date: 2018-03
• Subjects: Brucella melitensis -- Lipopolysaccharide -- Mouse model -- Subcutaneous route of infection -- Clinicopathological changes -- Histopathology -- Cytokine -- Antibody -- Hormone -- PCR; Pathogenic microorganisms -- Periodicals; Pathology, Molecular -- Periodicals; Communicable Diseases -- microbiology -- Periodicals; Communicable Diseases -- parasitology -- Periodicals; Micro-organismes pathogènes -- Périodiques; Pathologie moléculaire -- Périodiques; Electronic journals; 616.9041
• DOI: 10.1016/j.micpath.2018.01.007
• Languages: English
• ISSNs: 0882-4010

Abstract

Abstract: Brucella melitensis is a major zoonotic pathogen in which lipopolysaccharide (LPS) is believed to play a major role in the diseases pathogenesis. To study the immunopathophysiological aspects, we established a mouse model experimentally infected with whole cell of B. melitensis and its lipopolysaccharide via subcutaneous route of exposure. Eighty four mice, BALB/c, both sexes with equal gender distribution and 6-8 weeks-old were randomly assigned into 3 groups. Group 1 (n = 36) were subcutaneoulsy inoculated with 0.4 mL 10 9 of B. melitensis while group 2 (n = 36) were subcutaneously challenged with 0.4 mL 10 9 of LPS. Group 3 (n = 12) was challenged subcuatneously with phosphate buffered saline and served as a control group. Animals were observed for clinical signs, haematological and histopathological analysis for a period of 24 days post-inoculation. Our results revealed that B. melitensis infected group demonstrated significant clinical signs and histopathological evidence than LPS infected group. However, both infected groups showed elevated levels of interleukins (IL-1β & IL6), antibody levels (IgM & IgG) as early as 3 days post-infection with predominance in LPS infected group. For hormone analysis, low levels of progesterone, estradiol and testosterone were observed in both B. melitensis and LPS challenged groups throughout the study period. Moreover, in B. melitensis infected groups, the organism was re-isolated from the organs and tissues of gastrointestinal, respiratory and reproductive systems; thereby confirming the possible transmission of the disease dynamics. Moreover, LPS stimulated significantly the innate and acquired immune system without significant systemic dysfunction suggesting the potentiality of the protective properties of this component as an alternative vaccine for brucellosis infection. This report is the first detailed investigation comparing the infection progression and host responses in relation to the immunopathophysiological aspects in mouse model after subcutaneous inoculation with B. melitensis and its lipopolysaccharide. Highlights: Subcutaneous exposures of mouse model to lipopolysaccharide extracted from B. melitensis elicited high antibody and cytokine immune response. LPS stimulated significantly the innate and acquired immune system without significant systemic dysfunction suggesting potentiality of the protective properties of this component as an alternative vaccine for brucellosis infection. A validated experimental data of biological meaningful is further required to support the proposition that LPS may play a direct role in the sustainable control of B. melitensis infections.