CLINICAL AND REPRODUCTIVE PATHOLOGICAL CHANGES ASSOCIATED WITH &lt;i&gt;BRUCELLA MELITENSIS&lt;/i&gt; AND ITS LIPOPOLYSACCHARIDES IN FEMALE MICE VIA ORAL INOCULATION

Abdullah Abdullah

doi:10.3844/ajavsp.2013.104.111

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 (PBS-Control group), 0.4 mL of 109 cfu of B. melitensis and 0.4 mL of Lipopolysaccharides (LPS) extracted from 109cfu 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.

Highlights

Brucellosis is one of the most important infectious diseases caused by Brucella sp. that affects humans as well as domestic and wild animals, with reproductive disorders as the main problem in domestic animals (Megid et al, 2010; Silva et al, 2011)
Mice orally inoculated with Brucella melitensis showed mild clinical signs compared to that of control and LPS group, except for mild ruffled fur of mice in LPS group
This study revealed that mice in group 2 which were orally inoculated with B. melitensis showed mild clinical signs compared to mice that were inoculated with the bacterial LPS, which only showed mild ruffled fur

Summary

Introduction

Brucellosis is one of the most important infectious diseases caused by Brucella sp. that affects humans as well as domestic and wild animals, with reproductive disorders as the main problem in domestic animals (Megid et al, 2010; Silva et al, 2011). That affects humans as well as domestic and wild animals, with reproductive disorders as the main problem in domestic animals (Megid et al, 2010; Silva et al, 2011). The validly published species of Brucella are B. melitensis, B. Faez Firdaus Jesse Abdullah et al / American Journal of Animal and Veterinary Sciences 8 (3): 104-111, 2013 abortus, B. suis, B. ovis, B. canis and B. neotome (Lopes et al, 2010); with Brucella melitensis and Brucella ovis as the main causes of brucellosis in sheep and goats (Megid et al, 2010). Brucella melitensis are Gram-negative, aerobic, partially acid fast and facultative intracellular coccobacilli or short rods bacteria that cause brucellosis in sheep and goats and the most common species that infect humans (Yohannes et al, 2013). There will be a general decrease in herd fertility, an increase in lamb or kid mortality with a low weaning percentage, a decrease on milk production and an increased culling of males due to chronic lesion on reproductive organs (Megid et al, 2010)

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