CLINICAL AND REPRODUCTIVE PATHOLOGICAL CHANGES ASSOCIATED WITH <i>BRUCELLA MELITENSIS</i> AND ITS LIPOPOLYSACCHARIDES IN FEMALE MICE VIA ORAL INOCULATION

Abstract

Brucella melitensis (B. melitensis) are Gram-negative, aerobic, facultative intracellular bacteria that cause brucellosis that usually leads to abortion in sheep and goats. Three groups of equal number of 24 healthy female mice were used as animal models. They were orally inoculated with 0.4 mL of phosphate Buffered Saline (PBSControl group), 0.4 mL of 10 9 cfu of B. melitensis and 0.4 mL of Lipopolysaccharides (LPS) extracted from 10 9 cfu of B. melitensis (both as treatment groups). Clinical signs exhibited by the mice were observed for 10 days, after which the survived mice were euthanized by cervical dislocation. Following that, post mortem was conducted and histopathological study of the reproductive organs was carried out. B. melitensis group showed mild clinical signs compared to LPS group which showed normal behaviours except for mild ruffled fur, 14 and 34 h post-inoculation, respectively. The control group (PBS) showed normal behaviours. Histopathology results revealed that both B. melitensis and LPS groups showed mild to moderate infiltration of inflammatory cells in the reproductive organs, along with normal to mild findings of necrosis. Mild to moderate haemorrhage were found in the mice of B. melitensis group, while LPS group showed normal to mild haemorrhage and moderate to severe congestion of the ovary. The study proved that mice infected orally with B. melitensis developed mild clinical signs whereas mice orally inoculated by its LPS showed normal behavior except for the mild ruffled fur. Moreover, both groups of mice inoculated with B. melitensis immunogens developed pathological changes in the reproductive organs. The LPS of B. melitensis could be a potential candidate for the development of vaccines.

Gonado-hypophyseal lesions and reproductive hormonal changes in Brucella melitensis-infected mice and its lipopolysaccharides (LPSs)

“…The pathological changes observed in the ovaries of Brucella-infected mice were in agreement with that previously reported by Abdullah et al (2013a). In a related study, Abdullah et al (2013bAbdullah et al ( , 2014 observed more severe degenerative and inflammatory changes in male and female reproductive organs of mice following intraperitoneal inoculation of B. melitensis and its lipopolysaccharide.…”

“…The pellet obtained after the extraction was washed with 1 ml 70 % ethanol and dried. Seventy microliters of 10-mM Tris-HCl buffer at pH 8.0 was added to the pallet and allowed to dissolve by boiling for 2 min (Abdullah et al 2013a(Abdullah et al , b, 2014.…”

“…In a related study, Abdullah et al (2013a) reported that male and female mice orally inoculated with B. melitensis and its LPS showed mild clinical response and developed pathological changes in the reproductive organs. However, those inoculated through the intraperitoneal route showed more severe lesions (Abdullah et al 2013b.…”

Histopathology and Immunohistochemistry Assessments of Acute Experimental Infection by &lt;i&gt;Brucella melitensis&lt;/i&gt; in Bucks

“…In goats, brucellosis causes serious economic impact to goat farmers from abortions and stillbirths [2]. Infections by B. melitensis occur through mucous membrane of the nasopharynx as well as through ingestion of contaminated feed [3].…”