CLINICAL AND REPRODUCTIVE PATHOLOGICAL CHANGES ASSOCIATED WITH BRUCELLA MELITENSIS AND ITS LIPOPOLYSACCHARIDES IN FEMALE MICE VIA ORAL INOCULATION (original) (raw)
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American Journal of Animal and Veterinary Sciences, 2013
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 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.
Brucella melitensis (B. melitensis) is gram negative, aerobic bacteria that cause Brucellosis in humans' sheep and goats. Brucellosis causes abortion in wild and domestic animals resulting in enormous financial losses. Therefore, the purpose of this study was to evaluate the clinico-pathological changes associated with Brucella melitensis infection and its bacterial Lipopolysaccharides (LPS) in male mice. Three groups of 24 Balb/c male mice consisting of 8 mice in each group were used as an animal model for the study. The control group were inoculated intraperitoneally with 1 mL of Phosphate Buffered Solution (PBS) pH 7 while, the treatment groups were inoculated intraperitoneally with 1 mL×10 9 of B. melitensis colony and 1 mL×10 9 of Lipopolysaccharides (LPS) extracted from B. melitensis respectively. Mice that showed severe clinical signs and those that survived were euthanized by cervical dislocation method after 5 days of post infection subsequently, post mortem was conducted and histopathological studies were carried out. B. melitensis group showed severe clinical signs between 6 to 17 h of post inoculation compared to the PBS and LPS groups. The LPS group became lethargic 2 h post inoculation but, they become active after 5 h post inoculation, while the control group (PBS) exhibited normal responses. Histopathology results showed severe tissue alterations in the reproductive organs of the B. melitensis group compared to LPS group. In conclusion, the atrophy of the spermatocytes in the testes and degenerative necrosis of the pseudo stratified epithelium of the vas deferens in the B. melitensis group were severe while, LPS group showed moderate atrophy of the spermatocyte of the testes and severe degenerative necrosis of the pseudo stratified epithelium of the vas deferens.
Immunogenic properties of Brucella melitensis cell-wall fractions in BALB/c mice
Journal of Medical Microbiology, 1995
The immunogenicity of several Brucella melitensis cell-wall (CW) fractions was tested in BALB/c mice. These CW fractions were smooth lipopolysaccharide (S-LPS) fraction from smooth (S) B. melitensis strain 16M, sodium dodecyl sulphate-insoluble (SDS-I) CW fraction from B. melitensis strain 16M (S) undigested or digested with pepsin, and SDS-I CW fraction from rough (R) B. melitensis strain H38. The B. melitensis SDS-I CW fraction contained two major outer-membrane proteins (OMPs) of 25-27 kDa and 31-34 kDa, peptidoglycan (PG) and a small quantity (1.5 %) of LPS. One month after immunisation, mice were challenged with virulent B. melitensis strain H38 (S) and Brucella spleen counts were recorded on days 28 and 49 after challenge. Before challenge, as measured by ELISA, the highest antibody responses to S-LPS were observed in mice immunised with SDS-I CW fraction from B. melitensis strain 16M (S), whether digested with pepsin or undigested. All immunised mice, except those immunised with the SDS-I CW fraction from the R strain, showed higher IgGl than IgG2a antibody responses to S-LPS (IgGl : IgG2a ratio 3.64-7.71). Antibody responses to the 25-27-kDa OMP were very low, with the highest responses in the mice immunised with the SDS-I CW fraction from the R strain. These results indicated that, in BALB/c mice, these CW fractions probably induced Th2-dependent more than Thldependent antibody responses. The highest protection levels were produced by immunisation with the pepsin-digested SDS-I CW fraction from B. melitensis strain 16M (S) and by passive transfer of an anti-S-LPS monoclonal antibody (MAb 2E11; M epitope specificity). S-LPS fraction from B. melitensis strain 16M (S) or SDS-I CW fraction from B. melitensis strain H38 (R) did not induce significant protection. The absence of protection by S-LPS fraction could be explained by the low antibody titres induced by it. On day 49, protection conferred by pepsindigested SDS-I CW fraction from B. melitensis strain 16M (S) was significantly higher (p < 0.05) than by the untreated SDS-I CW fraction from the corresponding strain. Furthermore, the level of protection in mice immunised with the SDS-I CW fraction from the R strain and which were also passively immunised, 1 day before challenge, with the S-LPS specific MAb was lower than in mice treated with the anti-S-LPS MAb alone. These results indicate that immunity induced by the S strain B. melitensis SDS-I CW fraction is probably mainly S-LPS dependent and that even one or more protein components of this fraction may play an antagonistic role to immunity conferred by S-LPS.
Immune response strategies of Brucella melitensis and their antigens in rats
Iraqi Journal of Veterinary Sciences
Brucella melitensis is an intracellular bacterium and is the main brucella species that cause abortion and placenta retention in sheep and goats. It has many mechanisms to evade the immune response. The current study aimed to investigate Brucella melitensis strategies for producing immune responses in rats after challenging the bacterium. For this purpose, live and killed Brucella melitensis REV1 strain was given to rats subcutaneously, and immunological markers like TLR2, TLR4, IFN-γ, and anti-brucella antibodies were determined. The results showed that the level of immunological markers like TLR2 and TLR4 did not significantly increase in rat groups inoculated with live Brucella melitensis, while it increased in the rats' groups vaccinated with the sonicated Brucella melitensis; also, the results showed an increase in the level of IFN-γ and antibrucella antibody titers in all animal groups. The study concluded that the inoculation with killed bacteria and REV1 could protect the animals against challenging doses, as seen when the groups were inoculated with challenge dose of the bacterium.
Transboundary and Emerging Diseases, 2021
This study describes the pathological changes, antibody response, isolation and distribution patterns following exposure of non-pregnant goats to live Brucella melitensis. Eighteen healthy adult female goats were divided into two equal groups. Group 1 was infected via conjunctival sac with 109 cfu/ml of B. melitensis, while Group 2 was similarly exposed to sterile PBS. Serum and swabs from the eyes and vagina were collected at 5-day intervals. On days 15, 30 and 75 post-infection, 3 goats from each group were killed before the conjunctiva, ovary, oviduct, uterine horn, uterine body and vagina, the submandibular, prescapular and supramammary lymph nodes, the mammary gland, liver, spleen, urinary bladder and synovial membranes were collected for bacterial isolation and pathological study. Exposure of non-pregnant goats to B. melitensis did not produce clinical signs and gross lesions but produced mild necrosis and inflammation in the lymph nodes, the organs of reproductive tract, the mammary gland and urinary bladder. In general, microscopic lesions were most severe in the D75 goats, followed by D30 and D15 goats. Brucella melitensis was most frequent and significantly (p < .05) isolated from the D30 (64.4 ± 25.2%) and least from D15 goats (39.3 ± 26.0%) goats. The organs that were most frequently isolated were the uterus, followed by the mammary gland, supramammary lymph node and urinary bladder. Earliest isolation from the ocular swabs was on day 5, while the vaginal swabs were on day 20 post-infection. The antibody response showed first significant (p < .05) increase on day 15 and reached peak on day 45 post-infection, corresponding with the first detection of sero-converter goats by the RBPT at 15 days and by the CFT at 40 days post-infection. In conclusion, infected non-pregnant goats shed B. melitensis through the vagina by day 20. The sero-positive goats were detectable by RBPT after 15 days but by CFT after 40 days. Since both serological tests detected positive goats at different time period of infection, paired-serum samplings might reduce this discrepancy.
Veterinary Microbiology, 1991
A study was conducted to determine whether the protection induced in mice by a primary inoculation of lipopolysaccharide from Brucella abortus would be enhanced by a second inoculation given at different time intervals. Protection was challenged by exposure of the mice to a virulent culture of B. abortus strain 2308. Reduced mean viable count and/or splenic weights were the criteria of protection. There was no significant difference (P> 0.05) in the protective responses among mice given a single inoculation. Vaccinated mice were significantly (P<0.05) better protected than were nonvaccinated mice. Mice given vaccinal inoculations simultaneous with challenge exposure were less protected (P < 0.001) than were mice vaccinated prior to challenge, but were better protected (P < 0.010) than were nonvaccinated mice.
Infection and Immunity, 2002
ABSTRACTIntranasal immunization of mice with purifiedBrucella melitensislipopolysaccharide (LPS) as a noncovalent complex withNeisseria meningitidisgroup B outer membrane protein (GBOMP) elicited a high-titer anti-LPS systemic antibody response and a significant mucosal antibody response. The anti-LPS immunoglobulin G (IgG) antibody was predominantly of the IgG1 subtype, although there was some response of the IgG2a, IgG2b, and IgG3 subtypes. The antibody titer remained high for 16 weeks postimmunization. Immunized mice and sham-immunized control mice were challenged intranasally with 104CFU of virulentB. melitensisstrain 16 M 4 weeks after the second dose of vaccine. The numbers of bacteria in lungs, livers, and spleens at 3 days, 9 days, and 8 weeks postchallenge were determined. Bacteria were found in lungs of all mice on day 3, but there was no disseminated infection of liver or spleen. By day 9, 40% of the mice had infected spleens and livers. At 8 weeks postchallenge, spleens ...
Iraqi Journal of Veterinary Medicine, 2015
The aim of this study was to evaluate the cellular immune responses of salt-Extractable Brucella abortus S19 antigens with immunoadjuvant soluble βeta-glucan in BALB/C mice later challenged with B. abortus virulent strain. The 0.72mg/ml of SEBA was used according to the results obtained from experiment to determine the macrophages Nitric oxide production and delayed type hypersensitivity test. One hundred BALB/C mice were divided into four groups. G1 were injected i.p with 0.2 ml of saline, G2 were vaccinated S.C with 0.1ml (108 CFU/mouse) of B. abortus S19, G3 were vaccinated i.p. with 0.2 ml of salt-Extractable Brucella abortus S19 antigens and G4 were vaccinated i.p. with 0.2 ml of salt-Extractable Brucella abortus S19 antigens and 0.2ml βeta glucan. At 27 days after immunization the delayed type hypersensitivity test was conducted with the significant (P<0.05) an increase in the foot pad thickness of the G4 as compared to G3, G2 and G1. At day 30 of immunization all rema...