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Mass vaccination, which is one of the main control policies, provides herd immunity against infectious diseases. This could contribute to the control of the disease and eventually its eradication. The purpose of this study was to investigate the safety and humoral immune response of Brucella melitensis Rev.1 vaccine before the start of mass vaccination. A total of 741 sheep and goats were vaccinated conjunctivally. No adverse effect was observed after the vaccination of the animals. No abortion was seen in pregnant animals. Vaccine strain was isolated from some milk samples taken from only lactating vaccinated goats. Excretion of the vaccine strain was not intense and long-termed. Post-vaccination immune response was evaluated by serological tests, namely, Rose Bengal Plate Test, Serum Agglutination Test and Complement Fixation Test. One month after vaccination, the immune response was high, and the decrease of antibody titers was the highest four to six months after vaccination by inversely correlated with the age of the vaccinated animals. In conclusion, we observed that Brucella melitensis Rev.1 vaccine, used conjunctivally, was safe enough for the animals, and vaccinated animals had high vaccineinduced immune response. [ABSTRACT FROM AUTHOR]

Brucella melitensis infection remains a serious health threat to humans and livestock in poorer countries in the Middle East. Vaccination with the isolated crude protein protects against B. melitensis infection. In this study, the efficacy of protective and immunogenicity of a crude protein extract of B. melitensis is administered and evaluated in rats. The immunogenicity of crude protein in the animal blood was assessed by SDS-PAGE and Western blot. The results show that certain proteins were found to be more immunogenic; their molecular weights were (21, 23, 24, 25, 28,31, 34.45, 54.66,83 and 157 kDa). ELISA kits were used to measure the concentrations of IL-4 and IFN-in serum. In contrast to IFN-γ, this study found that the group receiving extracted protein had considerably higher serum levels of IL-4 compared to the control healthy and REV1 group. [ABSTRACT FROM AUTHOR]

Brucellosis is a highly contagious zoonotic disease with significant economic consequences. In the last 50 years, no brucellosis outbreak has been documented in Sierra Leone. In March 2021, Koinadugu District reported suspected cases of brucellosis in cattle. The study was aimed to confirm the diagnosis of disease, determine the magnitude of the outbreak, identify the sources of infection, and institute control measures. Brucellosis suspected case was any animal in the Koinadugu District with abortions, retention of placenta, stillbirth, the birth of weak offspring, or swelling of testicles, from February 21 to March 21, 2021. A confirmed case was any suspected case and laboratory positive for brucellosis. We interviewed livestock officials and animal owners, and reviewed clinical records to collect animals' clinical characteristics, travel history, and immunization status. Blood samples from animals with suspected brucellosis were collected for laboratory confirmation by Rose Bengal Test (RBT). We conducted active case searches at veterinary clinics and in the affected communities to identify additional cases and assessed the animal flock's environmental condition. Four Hundred (400) animals with suspected brucellosis had been reported, of which 150 were confirmed positive by RBT. All confirmed cases were female, where 135 (90%) between 1 and 2 years, and 15 (10%) were Heifers (12-14 months). Of the 150 confirmed cases, 100 (66%) were pregnant, among them, 25 (25%) were aborted. Almost half of the cases presented with vaginal discharge, retained placenta, and uterine infection. Three out of 50 cattle imported from Guinea died before being tested for brucellosis and no animals were vaccinated against brucellosis. No additional animal or human cases were reported. We observed that fetuses, aborted materials, and sick animal carcasses were left in open places for days before being disposed. Brucellosis outbreak was confirmed in Koinadugu District. Lack of vaccination might be responsible for the high infection rate. The source of the outbreak could be the introduction of infected animals from other farms. We distributed personal protective equipment and educated farmers about the safe disposing of aborted fetuses and placentas. We recommended enforcing the existing animal import regulations and also engaging in a nationwide vaccination campaign. [ABSTRACT FROM AUTHOR]

Copyright of Revista Cientifica de la Facultade de Veterinaria is the property of Universidad del Zulia, Facultad de Ciencias Veterinarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: The inadequate awareness of livestock breeders on brucellosis transmission, as well as their improper knowledge about preventing brucellosis is considered as one of the important barriers to animal vaccination against brucellosis. The present study aimed to design and validate a brucellosis prevention questionnaire focused on animal vaccination. The valid questionnaire was used to design, implement, and evaluate an interventional training program.Method: A brucellosis prevention questionnaire (BPQ) was developed in the exploratory psychometric study. In addition, face-to-face interviews were conducted to formulate its initial items, the results of which were merged with those obtained from literature review. Further, the face, content, and construct validity of the questionnaire were assessed by co-operating livestock breeders, veterinarians, and health educationists. The impact score (IS), and content validity ratio (CVR) and index (CVI) of the items were calculated, and the construct validity of the questionnaire was evaluated through factor analysis. Furthermore, the reliability of the results related to the questionnaire was measured by using Cronbach's alpha, intra-class correlation coefficient (ICC), and composite reliability, as well as the standard error of measurement (SEM).Results: The questionnaire was finalized with 53 items and its validity was confirmed by CVI (0.90), CVR (0.74), and IS (4.30). Additionally, the items were loaded into three constructs of awareness, attitude, and practice. Further, the predictive power of awareness, attitude, and practice was determined as 43.43, 15.81, and 15.78%, respectively. Furthermore, the fitness of the proposed model among the constructs was confirmed by the root mean square error of approximation (RMSEA) < 0.08, as well as normed chi-square (× 2/ df) < 5.0, comparative fit index (CFI) ≥ 0.90, and Tucker- Lewis index (TLI) ≥ 0.9.Conclusion: The brucellosis prevention questionnaire represented acceptable psychometric properties. The factors influencing the preventive behavior of livestock breeders can be identified by applying the questionnaire, and co-operating veterinarians and educational planners. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Surgery & Medicine (JOSAM) is the property of Journal of Surgery & Medicine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Residual virulence is a major drawback in current Brucella vaccines. Live vaccines induce abortions in pregnant animals. Hence, a novel anti- Brucella vaccine was developed utilizing rough Salmonella delivering four Brucella antigens. Safety implications during pregnancy, humoral immune responses, and protective efficacy against wild type Brucella was investigated in guinea pig model. The vaccine did not induce abortions or severe complications in pregnant guinea pigs when administered 4 × 108 CFU via intraperitoneal route. Systemic IgG determination against antigen components reveals induction of immunity via the Salmonella delivery. Protection efficacy against abortions was 33.3% (2/6) when midterm sow challenged with virulent Brucella 544 strain while none was protected in control group. Lower Brucella recovery in spleen and liver and reduced histopathological burden were also noticed. Although abortion induced by Brucella challenge was not completely prevented, the vaccine candidate may perform better with optimization of vaccination such as inoculation dose optimization. [ABSTRACT FROM AUTHOR]

Highlights • A NDV VLP based Brucella vaccine candidate was developed. • The Brucella antigen BCSP31 was linked to VLPs through a GPI modifying strategy. • The cVLPs proved its sufficient DCs activating ability in vivo and in vitro. • The cVLPs conferred full protection against the virulent B. melitensis strain 16 M. Abstract Brucellosis is a widespread zoonosis that poses a substantial threat to human and animal public health due to the absence of a sufficiently safe and efficient vaccine. Virus-like particles (VLPs) have been developed as novel vaccine candidates and suitable carrier platforms for the delivery of exogenous proteins. Herein, we constructed chimeric virus-like particles (cVLPs) assembled by a Newcastle disease virus (NDV) M protein and glycosylphosphatidylinositol-anchored Brucella BCSP31 protein (GPI-BCSP31). cVLPs-GPI-BCSP31 were highly efficient in murine dendritic cell (DC) activation, both in vitro and in vivo. Moreover, they elicited strong specific humoural immune responses detected through ELISA assay with inactivated Brucella and recombinant BCSP31 protein and by elevated cellular immune responses indicated by intracellular IFN-γ and IL-4 levels in CD3+CD4+ T and CD3+CD8+ T cells. Importantly, cVLPs-GPI-BCSP31 conferred protection against virulent Brucella melitensis strain 16 M challenge, comparable to the efficacy of Brucella vaccine strain M5. In summary, this study provides a new strategy for the development of a safe and effective vaccine candidate against virulent Brucella and further extends the application of NDV VLP-based vaccine platforms. [ABSTRACT FROM AUTHOR]

Brucellosis is a worldwide zoonosis causing important economic loss and a public health problem. Small ruminants are the preferred hosts of Brucella melitensis and thus the main source of human infections. Effective control of sheep and goat brucellosis has been achieved in several countries through vaccination with the live‐attenuated B. melitensis Rev1 vaccine. However, Rev1 induces a long‐lasting serological response that hinders the differentiation between infected and vaccinated animals. A Rev1::gfp strain expressing constitutively the Green Fluorescent Protein (GFP) was built by stable insertion of a mini‐Tn7‐gfp in the glmS‐recG non‐codifying chromosomal region. An associated indirect ELISA‐GFP was developed to identify anti‐GFP antibodies in vaccinated animals. The resulting Rev1::gfp kept the biological properties of the Rev1 reference strain, including residual virulence and efficacy in mice, and was readily distinguished from Rev1 and other Brucella field strains by direct visualization under ultraviolet illumination, fluorescence microscopy and a multiplex PCR‐GFP. The Rev1::gfp strain did not elicit anti‐GFP antibodies itself in lambs but when applied in combination with recombinant GFP induced an intense and long‐lasting (>9 months) anti‐GFP serological response readily detectable by the ELISA‐GFP. Overall, our results confirm that Rev1 GFP‐tagging can be a suitable alternative for identifying vaccinated sheep in infected contexts. [ABSTRACT FROM AUTHOR]

Brucellosis is considered as an endemic disease in yaks (Bos grunniens) in China, but few economic analyses describing the cost of the disease and potential benefits of control have been reported. The aim of the study was to estimate the economic cost of brucellosis in yaks and the economic value of three control strategies: (a) vaccination; (b) test‐and‐slaughter; and (c) a combination of vaccination and test‐and‐slaughter programs in Damxung and Maizhokunggar counties and Pali township of Yadong county in Tibet. Using data from a cross‐sectional seroprevalence survey conducted in 2015, combined with financial data, the predicted costs and benefits of the different control strategies were simulated over a 6‐year period. The annual estimated cost of brucellosis in yaks within the study area was US$ 521,043 (95% CI: US$ 334,441; US$ 759,862), with an annual average cost per yak estimated at US$ 1.42 (95% CI: US$ 0.91, US$ 2.07). The benefit‐cost analysis predicted that vaccination was the most effective control method with a benefit‐cost ratio (BCR) of 3.19 (95% CI: 2.17, 4.66) and a net present value (NPV) of US$ 313,355 (95% CI: US$ 157,679, US$ 541,062) over a 6‐year period. A sensitivity analysis found the NPV was most sensitive to the loss from a female yak aborting in the vaccination control program. In contrast, the price of yaks that were slaughtered had the largest influence on the NPV for both the test‐and‐slaughter control program and the combination control program. These estimates provide valuable information and establish a foundation for formulating and implementing cost‐effective measures for controlling the disease in yaks on the Tibetan plateau, and more broadly in China. [ABSTRACT FROM AUTHOR]

An anti-Brucella vaccine candidate comprised of purified Brucella lipopolysaccharide (LPS) and a cocktail of four Salmonella Typhimurium (ST)-Brucella vectors was reported previously. Each vector constitutively expressed highly conserved Brucella antigens (rB), viz., lumazine synthase (BLS), proline racemase subunit A, outer membrane protein-19 (Omp19), and Cu-Zn superoxide dismutase (SOD). The present study determined a relative level of protection conferred by each single strain. Upon virulent challenge, the challenge strain was recovered most abundantly in non-immunized control mice, with the ST-Omp19-, ST-BLS-, LPS-, and ST-SOD-immunized mice showing much less burden. Indirect enzyme-linked immunosorbent assay-based assay also confirmed the induction of antigen-specific immunoglobulin G for each antigen delivered. In a route-wise comparison of the combined vaccine candidate, intraperitoneal (IP), intramuscular (IM), and subcutaneous immunizations revealed an indication of highly efficient routes of protection. Splenocytes of mice immunized via IM and IP routes showed significant relative expression of IL-17 upon antigenic pulsing. Taken together, each of the Brucella antigens delivered by ST successfully induced an antigen-specific immune response, and it was also evident that an individual antigen strain can confer a considerable degree of protection. More effective protection was observed when the candidate was inoculated via IP and IM routes. [ABSTRACT FROM AUTHOR]

Brucella abortus strain 19 (S19), Brucella melitensis Rev 1 (Rev1), and B. abortus strain RB51 (RB51) are the three licensed animal brucellosis vaccines, and they have been most commonly and successfully used in prevent brucellosis in animals. However, many adverse events (AEs) have been associated with these three vaccines after their administering to animals or being accidentally exposed to humans. In this study, 27 peerreviewed publications containing animal and human AE reports associated with these three brucellosis vaccines were manually annotated from the PubMed database. Our meta-analysis identified 20 animal AEs and 46 human AEs associated with the three vaccines. Based on the Ontology of Adverse Events (OAE) hierarchical classification, these animal AEs were enriched in the immune and reproductive systems that might eventually result in the occurrence of abortion or infertility. The human AEs were concentrated in the behavioral and neurological conditions, and these AEs showed flu-like symptoms that are consistent with human brucellosis. Furthermore, an analysis of variance (ANOVA) statistics analysis with linear model fits was used to determine the major variables that might affect the occurrence of abortion AE in animals. The ANOVA results indicated that three variables (P-value < 0.05) are significantly associated with the occurrence of abortion AE: animal species, vaccination dose, and vaccination route. The other two variables (i.e., vaccine type and animal age at vaccination) did not significantly (P-value > 0.05) associated with the occurrence of abortion AE. Overall, this study represents the first ontology-based meta-analysis of adverse events associated with animal vaccines. The results of such a study led to the better understanding of brucellosis vaccine AEs, facilitating rational design of more secure and effective vaccines. [ABSTRACT FROM AUTHOR]

An anti- Brucella vaccine candidate comprising rough Salmonella vector delivering Brucella antigens was developed. This system provides a platform for live Brucella -free vaccine development as it can mimic active-intracellular infection of Brucella organism. Exploiting this phenomenon thus provides significant protection at a single dose and also re-assured the safety. To date, no human anti- Brucella vaccines are available, owing to the lack of safe and effective formulation. This study investigated the safety of the vaccine formulation in mice model and in vitro human cell cultures. The experiment was designed to determine the LD50 of the vaccine formulation. The vaccine formulation did not induce any mortality even when mice were administered at 8 × 10 9 CFU per oral or per subcutaneous (SC), which was 100-times more than the actual vaccine dose intended for mice model. In contrast, wild-type (WT) Salmonella positive control strain induced 100% mortality at 8 × 10 7 CFU per mice via oral or SC routes. Interaction of the vaccine with phagocytic (THP-1 derived macrophage) and non-phagocytic (Caco-2) human cell lines as well as human PBMC was investigated. In in vitro experiments, inflammatory and pyretic cytokines TNF-α, and IL-1β inductions were significantly lower in vaccine group as compared to WT group. Further, apoptosis, nitric oxide synthase and cytotoxicity inductions were comparable and not exacerbated, given that the strain is based on a rough bacterial vector that may have endotoxic lipid-A more readily exposed. These findings corroborated that the vaccine formulation is highly safe in mice model and is relatively mild in the induction of inflammatory cytokines and cellular changes in human cell lines. [ABSTRACT FROM AUTHOR]

Brucella poses a great threat to animal and human health, and vaccination is a good way of controlling the bacterium. In this study, the immune response and protection ability of a recombinant adenovirus Ad-LL/BP containing L7/L12 and BCSP31 proteins of Brucella abortus (B. abortus) were evaluated in BALB/c mice model. Firstly, Adenovirus vector Ad-CMV and the recombinant adenovirus Ad-LL/BP were amplified in HEK 293AD cells. The TCID50 values of Ad-LL/BP and Ad-CMV were 10-8.68/0.1 mL and 10-8.35/0.1 mL, respectively. Mice were inoculated with 100 TCID50/mouse of Ad-LL/BP or Ad-CMV. Vaccination of mice with Ad-LL/BP vaccine was able to elicit higher IgG, IgG1 and IgG2a antibody levels when compared with Ad-CMV and PBS control animals (P<0.05). Splenocytes from Ad-LL/BP-immunized mice significantly proliferated and released Th1 type cytokine IL-12 in comparison with Ad-CMV or PBS-inoculated groups (P<0.05). CD3+ and CD4+ T cell subset in splenocytes from the mice immunized with Ad-LL/BP vaccine were significantly higher compared with those from the mice vaccinated with Ad-CMV or PBS (P<0.05), but CD8+ T cells had no change in the three groups (P>0.05). Ad-LL/BP vaccine was able to reduce significantly the numbers of B. abortus in the spleens from the immunized mice. These results indicated that the recombinant Ad-LL/BP vaccine induced mainly cell-mediated immunity and partly humoral immunity, and provided moderately protection against B. abortus infection. Therefore, the vaccine could be further developed into a live-vector vaccine against B. abortus. [ABSTRACT FROM AUTHOR]

Brucellosis is one the serious infectious diseases caused deleterious health and economic losses. Vaccination with subunit vaccines is the efficient alternative way than live attenuated vaccines against infectious diseases. Herein a new chimeric OMP25-BLS antigen emulsified in Chitosan Nanoparticles was designed and its immune responses were compared with control groups. Also, the role of heat shock protein 60 kDa in combination with OMP25-BLS antigen was assessed. Structural and antigenic features of chimeric antigen were predicted using bioinformatics tools. Moreover, the humoral and cellular immune responses were measured by ELISA in seven different groups. Observations showed rOMP25-BLS structure was highly stable and antigenic. Cytokines analysis showed rOMP25 and rOMP25-BLS + rHSP60 induced higher titer of INF-γ than rHSP60 and rOMP25-BLS. There was no statistically significant difference between positive control group and rOMP25-BLS + rHSP60 in inducing TNF-α ( p  < .05). Additionally, the highest titer of IL-4 was dedicated to rOMP25 among other immunized treatments, while there were no significant differences between positive control group and other immunized groups with recombinant proteins ( p < .05). In addition, rOMP25-BLS and rHSP60 induced higher titer of total antibody compared to other groups. Also, rHSP60 could improve IgG2a to IgG1 ratio when it used in combination with chimeric antigen. Moreover, the lymphocyte proliferation index was higher in chimeric rOMP25-BLS + HSP60 antigen. In conclusion, while rOMP25-BLS chimeric antigen unable to induce efficient cellular response than individual injection of rOMP25, its injection in combination with rHSP60 could improve cellular immunity. [ABSTRACT FROM AUTHOR]

Recombinant engineering of immunologically active chimeric protein consisting of Omp19 and P39 domains of B . abortus (rOP), was purified under denaturing conditions upon expression in E . coli BL21 (DE3) and refolded to dynamic form. The immuno-protective efficacy of rOP was evaluated by challenging the BALB/c mice intraperitoneally (I.P) with the infective species of Brucella in the absence or presence of adjuvants, such as Aluminum hydroxide gel (Al), or Freund’s Complete Adjuvant (FCA)/Incomplete Freund’s Adjuvant (IFA). Surprisingly, after second boosting, mice received rOP per se were found to be immunogenic in terms of IgG response with the dominant expression of IgG2a and significant IFN-γ by splenic T cells, suggesting that rOP is a strong inducer of anti- Brucella immunity. The resulted anti-rOP antibodies recognized native Omp19 and P39 among species of Brucella with distinct double bands and single band against chimera in immunoblotting. An enhanced and comparable antibody response with varied IgG isotype combinations were noticed in the mice primed and boosted with rOP in adjuvants. However, rOP + FCA/IFA formulation was found to be the most effective in lymphocyte recall assays at inducing significant ( P < 0.001 ) proliferation index (P.I.) as well as increased Th1-coupled cytokines (IFN-γ, IL-2 and IL-12p70) than rOP + Al in response to rOP re-stimulation. Furthermore, in vitro defensive assay revealed that compared to anti-rOP antisera, the polyclonal anti-sera from rOP + adjuvants exhibited enhanced protection of RAW264.7 cells against virulent challenge by B . melitensis 16M and B . abortus 544. In addition, compared to sham group, enumeration of Brucella CFU after challenge with the above species showed a significant ( P < 0.01 ) reduction of bacteria (log CFU) in the macrophage cell lines and organs of vaccinated mice. On the whole, a relatively higher and faster reduction was noticed in the mice vaccinated with similar amount of purified antigen in Freund’s adjuvant. Ability of inducing Th1 directed immune protection in the absence of adjuvant support, postulated rOP as a plausible entrant for developing a chimeric based subunit vaccine against Brucella . [ABSTRACT FROM AUTHOR]

Brucella melitensis is an intracellular pathogen resides in the professional and non-professional phagocytes of the host, causing zoonotic disease brucellosis. The stealthy nature of the Brucella makes it's highly pathogenic, and it is hard to eliminate the bacteria completely from the infected host. Hitherto, no licensed vaccines are available for human brucellosis. In this study, we identified potential antigens for vaccine development from non-classically secreted proteins through reverse vaccinology approach. Based on the systemic screening of non-classically secreted proteins of B. melitensis 16M, we identified nine proteins as potential vaccine candidates. Among these, Omp31 and Omp22 are known immunogens, and its role in the virulence of Brucella is known . Roles of other proteins in the pathogenesis are yet to be studied. From the nine proteins, we identified six novel antigenic epitopes that can elicit both B-cell and T-cell immune responses. Among the nine proteins, the epitopes were predicted from Omp31 immunogenic protein precursor, Omp22 protein precursor, extracellular serine protease, hypothetical membrane-associated protein, iron-regulated outer membrane protein FrpB. Further, we designed a multitope vaccine using Omp31 immunogenic protein precursor, Omp22 protein precursor, extra cellular serine protease, iron-regulated outer membrane protein FrpB, hypothetical membrane-associated protein, and LPS-assembly protein LptD and polysaccharide export protein identified in the previous study. Epitopes were joined using amino acid linkers such as EAAAK and GPGPG. Cholera toxin subunit B, the nontoxic part of cholera toxin, was used as an adjuvant and it was linked to the N-terminal of the multitope vaccine candidate. The designed vaccine candidate was modeled, validated and the physicochemical properties were analyzed. Results revealed that the vaccine candidate is soluble, stable, non-allergenic, antigenic and 87% of residues of the designed vaccine candidate is located in the favored region. In conclusion, the computational analysis showed that the newly designed multitope protein could be used to develop a promising vaccine for human brucellosis. [ABSTRACT FROM AUTHOR]

Brucella species are important etiological agents of zoonotic diseases. Attenuated Salmonella strains expressing Brucella abortus BCSP31, Omp3b and superoxide dismutase proteins were tested as vaccine candidates in this study. In order to determine the optimal dose for intraperitoneal (IP) inoculation required to obtain effective protection against brucellosis, mice were immunized with various doses of a mixture of the three vaccine strains. Fifty BALB/c mice were divided into five equal groups (groups A-E). Group A mice were intraperitoneally inoculated with 100 µL of sterile phosphate-buffered saline. Group B, C, D and E mice were intraperitoneally immunized with approximately 1.2 × 105 colony-forming units (CFU) mL-1 of Salmonella containing pMMP65 in 100 µL and with 1.2 × 104 CFU mL-1, 1.2 × 105 CFU mL-1 and 1.2 × 106 CFU mL-1 of the mixture of the three strains in 100 µL, respectively. Serum IgG, tumor necrosis factor alpha and interferon gamma concentrations were significantly higher in group E than in groups A-D. Following challenge with B. abortus 544, the challenge strain was not detected in the spleen of any mouse from group E. Thus, IP immunization with 1.2 × 106 CFU mL-1 of the mixture of the three vaccine strains induced immune responses and provided effective protection against brucellosis in mice. [ABSTRACT FROM AUTHOR]

Background: In Argentina, vaccination with Brucella abortus Strain 19 vaccine is mandatory. The objective of the study was to develop and test a method for evaluating, in an innovative way, some farmers' and veterinarians' management practices in relation to brucellosis and to assess the vaccination campaign and coverage. The work took place in Brandsen and Navarro districts. Four questionnaires were designed (for officials from Local Sanitary Entities, vaccinators, vet practitioners and farmers). Responses were coded as "ideal" (0) and "not ideal" (1). To assess the relative weight of each question ("item"), experts ranked the items according to their impact on management practices and vaccination. A weighted score was then calculated. A higher weighted score was assigned to the worse practices. Farmers obtaining a global weighted score above the third quartile were classified as "inappropriately managed farms", to be compared per type of production system and district. To assess the immunization coverage, female calves were sampled 30 to 50 days post vaccination; they were expected to react positively to serological diagnostic tests (DT+). Results: There were significantly more inappropriately managed farms and higher global scores among beef farmers and in Brandsen. Eighty three percent (83%) of female calves were DT+, significantly under the ideal immunization coverage (95%). Only 48% of farms were considered well vaccinated. DT+ results were positively associated with the Brandsen district (OR = 25.94 [4.60-1146.21] and with the farms having more than 200 cow heads ((OR = 78.34 [4.09- 1500.00]). On the contrary, DT+ were less associated with vaccinators being veterinary practitioners (OR = 0.07 [0.006-0. 78]). Farmers are well advised by their veterinary practitioners but they should improve some management practices. Conclusions: The vaccination campaign is globally well implemented, but the immunization coverage and some vaccinators' practices should be improved. This study leads to a better understanding of the most common used management and control practices regarding brucellosis, which affect its epidemiology. Any vaccination campaign should be periodically assessed to highlight possible fails. The described methodology can be extrapolated to other countries and different contexts. [ABSTRACT FROM AUTHOR]

Brucella is Gram-negative intracellular bacterial pathogen that infects humans and animals and contributes to great economic losses in developing countries. Presently, live attenuated Brucella vaccines ( Brucella melitensis M5-90) are the most effective means of brucellosis control and prevention in animals. However, these vaccines have several drawbacks, such as an inability to distinguish between a natural infection and immunization and an association with abortions in pregnant animals. Therefore, this study constructed a Brucella M5-90Δbp26 mutant and evaluated its virulence. The survival of the M5-90Δbp26 mutant was attenuated in human placenta trophoblastic 8 cells (HPT-8 cells) and in BALB/c mice, with a high immunoprotectivity noted in mice. Furthermore, safety tests showed that the M5-90Δbp26 mutant was less virulent than the M5-90 vaccine strain. Additionally, an indirect enzyme-linked immunosorbent assay (ELISA) screening was shown to detect the presence of Brucella protein 26 (BP26) with high sensitivity, with M5-90Δbp26 inoculation accompanied with a lack of BP26 expression, and was further confirmed by western blotting. Together, the M5-90Δbp26 mutant and the indirect ELISA can be employed to distinguish vaccinated livestock from infected animals. [ABSTRACT FROM AUTHOR]

Brucellosis is known as one of important zoonosis. Studying the histological and biochemical effects of the disease could help to increase our knowledge about it. The aim of the present study was to evaluate changes of plasma parameters after intraperitoneal injection of two species of Brucella ( Brucella melitensis and Brucella abortus ) and two vaccines (Rev-1, RB-51) in the rat. Forty male rats were divided into five groups (n = 8 in each group). Two groups received suspensions of Brucella abortus and Brucella melitensis and two other groups were injected intraperitoneally with two mentioned vaccines and the last group received only distilled water. The results showed a significant increase in sphingosine 1-phosphate, Malondialdehyde, hepcidin, homocysteine, cardiac troponin I and copper levels and a considerable decrease in the levels of iron and zinc (P ≤ 0.01) in infected groups compared to the control animals. In vaccinated groups, hepcidin was increased but other parameters were not changed in comparison to the control group. It can be concluded that increase of homocysteine and cardiac troponin I in brucellosis could be a warning for cardiac adverse effects. Besides, increase of sphingosine 1-phosphate probably indicates its stimulant and modulatory effects in anti- Brucellosis biochemical pathways of the host. [ABSTRACT FROM AUTHOR]

The search for ideal brucellosis vaccines remains active today. Currently, no licensed human or canine anti-brucellosis vaccines are available. In bovines, the most successful vaccine (S19) is only used in calves, as adult vaccination results in orchitis in male, prolonged infection, and possible abortion complications in pregnant female cattle. Another widely deployed vaccine (RB51) has a low protective efficacy. An ideal vaccine should exhibit a safe profile as well as enhance protective efficacy. However, currently available vaccines exhibit one or more major drawbacks. Smooth live attenuated vaccines suffer shortcomings such as residual virulence and serodiagnostic interference. Inactivated vaccines, in general, confer relatively low levels of protection. Recent developments to improve brucellosis vaccines include generation of knockout mutants by targeting genes involved in metabolism, virulence, and the lipopolysaccharide synthesis pathway, as well as generation of DNA vaccines, mucosal vaccines, and live vectored vaccines, have all produced varying degrees of success. Herein, we briefly review the bacteriology, pathogenesis, immunological implications, candidate vaccines, vaccinations, and models related to Brucella. [ABSTRACT FROM AUTHOR]

Current investigations have demonstrated that a multi-epitope peptide vaccine targeting multiple antigens could be considered as an ideal approach for prevention and treatment of brucellosis. According to the latest findings, the most effective immunogenic antigens of brucella to induce immune responses are included Omp31, BP26, BLS, DnaK and L7–L12. Therefore, in the present study, an in silico approach was used to design a novel multi-epitope vaccine to elicit a desirable immune response against brucellosis. First, five novel T-cell epitopes were selected from Omp31, BP26, BLS, DnaK and L7–L12 proteins using different servers. In addition, helper epitopes selected from Tetanus toxin fragment C (TTFrC) were applied to induce CD4 + helper T lymphocytes (HTLs) responses. Selected epitopes were fused together by GPGPG linkers to facilitate the immune processing and epitope presentation. Moreover, cholera toxin B (CTB) was linked to N terminal of vaccine construct as an adjuvant by using EAAAK linker. A multi-epitope vaccine was designed based on predicted epitopes which was 377 amino acid residues in length. Then, the physico-chemical properties, secondary and tertiary structures, stability, intrinsic protein disorder, solubility and allergenicity of this multi-epitope vaccine were assessed using immunoinformatics tools and servers. Based on obtained results, a soluble, and non-allergic protein with 40.59 kDa molecular weight was constructed. Expasy ProtParam classified this chimeric protein as a stable protein and also 89.8% residues of constructed vaccine were located in favored regions of the Ramachandran plot. Furthermore, this multi-epitope peptide vaccine was able to strongly induce T cell and B-cell mediated immune responses. In conclusion, immunoinformatics analysis indicated that this multi-epitope peptide vaccine can be effectively expressed and potentially be used for prophylactic or therapeutic usages against brucellosis. [ABSTRACT FROM AUTHOR]

Aim: Brucellosis is a major bacterial zoonosis of global importance affecting a range of animal species and man worldwide. It has economic, public health, and bio-risk importance. Control and prevention of animal brucellosis mainly depend on accurate diagnostic tools and implementation of effective and safe animal vaccination program. There are three types of animal Brucella live vaccines - Brucella melitensis Rev-1 vaccine, Brucella abortus S19, and B. abortus RB51. Evaluation of these vaccines depends mainly on enumeration of Brucella viable count. At present, used colony count method is time consuming, costly and requires especial skills. Hence, the aim of this study is to use and standardize real-time polymerase chain reaction (RT-PCR) as an alternative, quantitative, sensitive, and rapid method to detect the colony count of Brucella in live Brucella vaccine. Materials and Methods: Four batches of different live Brucella vaccines were evaluated using of conventional bacterial count and RT-quantitative PCR (RT-qPCR) using BSCP31 gene specific primers and probe. Standard curve was generated from DNA template extracted from 10-fold serial dilution of living B. abortus RB51 vaccine to evaluate the sensitivity of RT-qPCR. Results: Results revealed that three batches of living Brucella vaccines were acceptable for Brucella colony count when traditional bacterial enumeration method was used. Results of RT-qPCR were identical to that of conventional bacterial count. Conclusions: Results concluded that RT-qPCR was relatively sensitive compared to traditional bacterial colony count of these vaccines. [ABSTRACT FROM AUTHOR]

Intracellular pathogen Salmonella exhibits natural infection broadly analogous to Brucella , this phenomenon makes Salmonella a pragmatic choice for an anti- Brucella vaccine delivery platform. In this study we developed and formulated a combination of four attenuated Salmonella Typhimurium live vector strains delivering heterologous Brucella antigens (rBs), namely lumazine synthase, proline racemase subunit A, lipoprotein outer membrane protein-19, and Cu-Zn superoxide dismutase. With an aim to develop a cross-protecting vaccine, Brucella pan-species conserved rBs were selected. The present study compared the efficacy of smooth and rough variants of Salmonella delivery vector and also evaluated the inclusion of purified Brucella lipopolysaccharide (LPS) in the formulation. Immunization of SPF-BALB/c mice with the vaccine combinations significantly (P ≤ 0.05) reduced splenic wild-type Brucella abortus 544 colonization as compared to non-immunized mice as well as Salmonella only immunized mice. Increased induction of Brucella specific-IgG, sIgA production, and antigen-specific splenocyte proliferative responses were observed in the mice immunized with the formulations as compared to naïve or vector only immunized mice. Modulatory effects of rB and LPS on production of interleukin (IL)-4, IL-12, and interferon-γ were detected in splenocytes of mice immunized with the formulation. Rough Salmonella variant in combination with LPS could further enhance the efficacy of the delivery when applied intraperitoneally. Taken together, it is compelling that Brucella LPS-augmented Salmonella vector delivering immunogenic Brucella proteins may be more suitable than the current non-ideal live Brucella abortus vaccine. The vaccine system also provides a basis for the development of cross-protecting vaccine capable of preventing multispecies brucellosis. [ABSTRACT FROM AUTHOR]

The purpose of the present study was to evaluate the immunogenicity and protective efficacy of the truncated form of outer membrane protein 2b (TOmp2b) from Brucella abortus in BALB/c mice. Three immunization regimens Protein/Protein, DNA/DNA and DNA/Protein were used. Immunization of mice with all vaccine strategies elicited a strong specific IgG responses (IgG2a titers over IgG1) and provided T helper1 (Th1) oriented immune responses. Furthermore, Protein/Protein (Pro/Pro-) and DNA/Pro- vaccinated groups conferred protection levels against B. abortus challenge not significantly different from those induced by B. abortus RB51 vaccine stain. In conclusion, TOmp2b is potential to stimulate specific immune responses and to confer cross protection against B. melitensis and B. abortus infection. Therefore, TOmp2b could be introduced as a new subunit vaccine candidate against Brucella infection. [ABSTRACT FROM AUTHOR]

There is a requirement to develop an novel vaccine to distinguish between vaccinated and infected animals after vaccination. Two mutants of Brucella melitensis M5-90Δbp261 and M5-90Δbp262, knockout of the fragments amino acids 55-152 and 22-185 respectively, were primarily generated. Then the two mutants were inoculated 7 weeks old BALB/c mice with 3.0 × 106 CFU/0.2 mL parent or mutant strains, Serum samples were evaluated by Rose Bengal plate tests, serum agglutination tests, colloidal gold immunochromatographic strips (ICS) coated with VirB5 or BP26 and indirect enzyme-linked immunosorbent assays. Spleen tissue samples were used to determine B. melitensis abundance at 10, 20, 30, and 40 days post-immunization (dpi). The serological results showed that the parent and mutant strains elicited a weak immunological reaction at 10-30 dpi. Fewer colony forming units (CFUs) were recovered from spleens in mutant strains group than the parent strain group during 20-40 post-immunization (dpi). The ICS were able to distinguish between the sera from mice immunized with either a parent or mutant strain of B. melitensis. These results indicate that the two mutants strain of B. melitensis have potentially perspectives in distinguishing infected animals from vaccination combined with ICS in this study. [ABSTRACT FROM AUTHOR]

Brucellosis, caused by Brucella spp., is an important zoonosis worldwide. Vaccination is an effective strategy for protection against Brucella infection in livestock in developing countries and in wildlife in developed countries. However, current vaccine strains including S19 and RB51 are pathogenic to humans and pregnant animals, limiting their use. In this study, we constructed the Brucella abortus (B. abortus) S2308 mutant strain Δ22915, in which the putative lytic transglycosylase gene BAB_RS22915 was deleted. The biological properties of mutant strain Δ22915 were characterized and protection of mice against virulent S2308 challenge was evaluated. The mutant strain Δ22915 showed reduced survival within RAW264.7 cells and survival in vivo in mice. In addition, the mutant strain Δ22915 failed to escape fusion with lysosomes within host cells, and caused no observable pathological damage. RNA-seq analysis indicated that four genes associated with amino acid/nucleotide transport and metabolism were significantly upregulated in mutant strain Δ22915. Furthermore, inoculation of Δ22915 at 105 colony forming units induced effective host immune responses and long-term protection of BALB/c mice. Therefore, mutant strain Δ22915 could be used as a novel vaccine candidate in the future to protect animals against B. abortus infection. [ABSTRACT FROM AUTHOR]

In the present study, immunogenicity and protective efficacy of the Brucella outer membrane protein 2b (Omp2b) was evaluated in BALB/c mice using Protein/Protein, DNA/DNA and DNA/Protein vaccine strategies. Immunization of mice with three vaccine regimens elicited a strong specific IgG response (higher IgG2a titers over IgG1 titers) and provided Th1-oriented immune response. Vaccination of BALB/c mice with the DNA/Pro regimen induced higher levels of IFN-γ/IL-2 and conferred more protection levels against B. melitenisis and B. abortus challenge than did the protein or DNA alone. In conclusion, Omp2b is able to stimulate specific immune responses and to confer cross protection against B. melitensis and B. abortus infection. Therefore, it could be introduced as a new potential candidate for the development of a subunit vaccine against Brucella infection. [ABSTRACT FROM AUTHOR]

In 2011, a human brucellosis case with severe clinical symptoms was reported at the University Clinic for Infectious Diseases in Prishtina, Kosovo. A trace-back investigation was conducted to find the source of human infection. A total of 49 blood samples and 15 corresponding milk samples from sheep and goats raised on the patient's farm were taken for serological and molecular analysis. Serology using RBT and CFT revealed 11 positive animals. Twelve milk samples were PCR positive. A Brucella strain isolated from a goat's milk sample was classified as Brucella melitensis biovar 3, indicating the first ever isolation and report in Kosovo. The use of the Bruce-ladder PCR provided differentiation between the field strain and the vaccine strain. Hence, the accidental transmission of the vaccine strain Rev 1 that was previously used for the vaccination of the farm animals could be excluded. The findings of this study show that brucellosis is still a public health threat in Kosovo despite control measures. [ABSTRACT FROM AUTHOR]

Brucellosis is a livestock disease responsible for fetal loss due to abortions. Worldwide, this disease has profound economic and social impact by reducing the ability of livestock producers to provide an adequate supply of disease-free meat and dairy products. In addition to its presence in domesticated animals, brucellosis is harbored in a number of wildlife species creating new disease reservoirs, which adds to the difficulty of eradicating this disease. Broad and consistent use of the available vaccines would contribute in reducing the incidence of brucellosis. Unfortunately, this practice is not common. In addition, the current brucellosis vaccines cannot provide sterilizing immunity, and in certain circumstances, vaccinated livestock are not protected against co-mingling Brucella -infected wildlife. Given that these vaccines are inadequate for conferring complete protection for some vaccinated livestock, alternatives are being sought, and these include genetic modifications of current vaccines or their reformulations. Alternatively, many groups have sought to develop new vaccines. Subunit vaccines, delivered as a combination of soluble vaccine plus adjuvant or the heterologous expression of Brucella epitopes by different vaccine vectors are currently being tested. New live attenuated Brucella vaccines are also being developed and tested in their natural hosts. Yet, what is rarely considered is the route of vaccination which could improve vaccine efficacy. Since Brucella infections are mostly transmitted mucosally, mucosal delivery of a vaccine has the potential of eliciting a more robust protective immune response for improved efficacy. Hence, this review will examine these questions and provide the status of new vaccines for livestock brucellosis. [ABSTRACT FROM AUTHOR]

Background/Objectives: In spite of all the research effort for developing new vaccines against brucellosis, it remains unclear whether these new vaccine technologies will in fact become widely used. The goal of this study was to perform a meta-analysis to identify parameters that influence vaccine efficacy as well as a descriptive analysis on how the field of Brucella vaccinology is advancing concerning type of vaccine, improvement of protection on animal models over time, and factors that may affect protection in the mouse model. Methods: A total of 117 publications that met the criteria were selected for inclusion in this study, with a total of 782 individual experiments analyzed. Results: Attenuated (n = 221), inactivated (n = 66) and mutant (n = 102) vaccines provided median protection index above 2, whereas subunit (n = 287), DNA (n = 68), and vectored (n = 38) vaccines provided protection indexes lower than 2. When all categories of experimental vaccines are analyzed together, the trend line clearly demonstrates that there was no improvement of the protection indexes over the past 30 years, with a low negative and non significant linear coefficient. A meta-regression model was developed including all vaccine categories (attenuated, DNA, inactivated, mutant, subunit, and vectored) considering the protection index as a dependent variable and the other parameters (mouse strain, route of vaccination, number of vaccinations, use of adjuvant, challenge Brucella species) as independent variables. Some of these variables influenced the expected protection index of experimental vaccines against Brucella spp. in the mouse model. Conclusion: In spite of the large number of publication over the past 30 years, our results indicate that there is not clear trend to improve the protective potential of these experimental vaccines. [ABSTRACT FROM AUTHOR]

Control of ovine brucellosis with subcellular vaccines can solve some drawbacks associated with the use of Brucella melitensis Rev.1. Previous studies have demonstrated that the polymeric antigen BLSOmp31 administered by parenteral route was immunogenic and conferred significant protection against B. ovis in rams. Immunization with BLSOmp31 by conjunctival route could be efficient for the induction of mucosal and systemic immune responses. In this work, we evaluated the conjunctival immunization using a thermoresponsive and mucoadhesive in situ gel composed of Poloxamer 407 (P407) and chitosan (Ch) as vaccine delivery system for BLSOmp31 in rams. Serum samples, saliva, lacrimal, preputial and nasal secretions were analyzed to measure specific IgG and IgA antibodies. Cellular immune response was evaluated in vivo and in vitro. Immunization with BLSOmp31-P407-Ch induced high IgG antibody levels in serum and preputial secretions which remained at similar levels until the end of the experiment. Levels of IgG in saliva, lacrimal and nasal secretions were also higher compared to unvaccinated control group but decreased more rapidly. IgA antibodies were only detected in nasal and preputial secretions. BLSOmp31-P407-Ch stimulated a significant cellular immune response in vivo and in vitro . The induction of systemic and local immune responses indicates a promising potential of P407-Ch for the delivery of BLSOmp31 by conjunctival route. [ABSTRACT FROM AUTHOR]

Brucellosis is a well-known domestic animal infectious disease, which is caused by Brucella bacterium. The outer membrane protein 25 kDa (Omp25) gene plays an important role in simulating of TNF-α, IFN-α, macrophage, and cytokines cells. In the current study molecular cloning and expression analysis of Omp25 gene for designing a subunit vaccine against Brucella was investigated. Amplifying the full length of candidate gene was performed using specific primers. Sub-cloning of this gene conducted using pTZ57R/T vector in TOP10F'strain of Escherichia coli(E.coli) as the host. Also, pET32(a)+ vector used for expression in BL21 (DE3) strain of E.coli. Omp25 gene with 642 bp size was amplified and cloned successfully. The expression results were confirmed by sequencing and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analyses which showed 42 kDa protein band correctly. Also, phylogenic analysis showed this gene has a near genetic relation with other Brucella strains. According to our results we can propose this gene as a candidate useful for stimulation of cell-mediated and humoral immunity system in future study. [ABSTRACT FROM AUTHOR]

The Brucella abortus general stress response (GSR) system regulates activity of the alternative sigma factor, σ E1 , which controls transcription of approximately 100 genes and is required for persistence in a BALB/c mouse chronic infection model. We evaluated the host response to infection by a B. abortus strain lacking σ E1 (Δ rpoE1 ), and identified pathological and immunological features that distinguish Δ rpoE1 -infected mice from wild-type (WT), and that correspond with clearance of Δ rpoE1 from the host. Δ rpoE1 infection was indistinguishable from WT in terms of splenic bacterial burden, inflammation and histopathology up to 6 weeks post-infection. However, Brucella -specific serum IgG levels in Δ rpoE1 -infected mice were 5 times higher than WT by 4 weeks post-infection, and remained significantly higher throughout the course of a 12-week infection. Total IgG and Brucella -specific IgG levels peaked strongly in Δ rpoE1 -infected mice at 6 weeks, which correlated with reduced splenomegaly and bacterial burden relative to WT-infected mice. Given the difference in immune response to infection with wild-type and Δ rpoE1 , we tested whether Δ rpoE1 confers protective immunity to wild-type challenge. Mice immunized with Δ rpoE1 completely resisted WT infection and had significantly higher serum titers of Brucella -specific IgG, IgG2a and IFN-γ after WT challenge relative to age-matched naïve mice. We conclude that immunization of BALB/c mice with the B. abortus GSR pathway mutant, Δ rpoE1 , elicits an adaptive immune response that confers significant protective immunity against WT infection. [ABSTRACT FROM AUTHOR]

Shiga toxin producing Escherichia coli (STEC) are bacterial pathogens involved in food-borne diseases. Shiga toxin (Stx) is the main virulence factor of STEC and is responsible for systemic complications including Hemolytic Uremic Syndrome (HUS). It has been previously demonstrated that Shiga toxin type 2 (Stx2) induces pregnancy loss in rats in early stage of pregnancy. The main purpose of this study was to determine if an active immunization prevents Stx2 mediated pregnancy loss and confers passive protective immunity to the offspring. For that purpose Sprague Dawley female rats were immunized with the chimera based on the enzyme lumazine synthase from Brucella spp . (BLS) and the B subunit of Shiga toxin 2 (Stx2B) named BLS-Stx2B. After immunization females were mated with males. At day 8 of gestation, dams were challenged intraperitoneally with a sublethal and abortifacient dose of Stx2. The immunization induced high anti-Stx2B-specific antibody titers in sera and most important, prevented pregnancy loss. Pups born and breastfeed by immunized dams had high anti-Stx2B-specific antibody titers in sera. Cross-fostering experiments indicated that passive protective immunity against Stx2 was transmitted through lactation. These results indicate that immunization of adult female rats with BLS-Stx2B prevents Stx2-induced pregnancy loss and confers anti Stx2 protective immunity to the offspring. [ABSTRACT FROM AUTHOR]

Brucellosis is considered to be the most widespread zoonosis throughout the world. It has a serious implication on human health as well as on the economic development in a developing country like Bangladesh. The objective of the present study was to determine the seroprevalence and to delineate the risk factors for Brucella seropositivity in small ruminants in Mymensingh district of Bangladesh. In the present study, serum samples were collected from a total of 2456 small ruminants (1710 goat and 746 sheep) from 13 upazilla of Mymensingh district. The data related to age, sex and location were also collected using a questionnaire. Serum samples were screened using Rose Bengal Test (RBT) and Enzyme Linked Immunosorbent Assay (ELISA). Seroprevalence of brucellosis was 9.53% in goats and 9.92% in sheep on RBT test. In goat, the highest Brucella antibody was observed in Mymensingh sadar upazilla (13%) followed by Dhobaura upazilla (12.9%). On the other hand, highest ovine Brucella antibody observed in Haluaghat upazilla (13.04%) followed by Mymensingh sadar (12.5%). The prevalence was more in adults (55.2% in goats and 57% in sheep) than young (8.6% in goat and 8.1% in sheep) and more in female goats (41.1%) and sheep (39.2%) than male goats (14.1%) and sheep (18%). ELISA test showed 33.70% (31 out of 92 RBT positive samples) positive reaction of total RBT positive reactors. The result of this study can be useful to initiate and establish a program for controlling and prevention through test and slaughter, culling of infected animal from flock and vaccination. [ABSTRACT FROM AUTHOR]

Live, attenuated Brucella vaccines are considered effective but can induce abortions in pregnant animals and are potentially infectious to humans. There is a strong need to improve the immunoprotective effects and safety of vaccines against Brucella . Currently, subunit vaccines have been demonstrated to be safe and efficacious alternatives in both humans and animals. In this study, we employed bioinformatics tools to predict B and T cell epitopes to aid development of a novel recombinant multi-epitope antigen for brucellosis vaccination. To evaluate the protective capacity of the recombinant antigen, the antigen’s efficacy was studied in a mouse model of brucellosis. Our results indicated that BALB/c mice immunized with this recombinant multi-epitope antigen showed mixed Th1-Th2 immune responses with high levels of specific IgG and exhibited high degrees of IFN-γ and IL-6 and significantly higher CD3, CD4, and CD8 frequencies compared to the control group. The recombinant antigen and vaccine strain M5-90 also provided protection against Brucella melitensis 16 M infection. Using bioinformatics tools to develop candidate vaccines is a promising strategy for the development of Brucella vaccines. [ABSTRACT FROM AUTHOR]

Brucellosis is one of the most common and widely spread zoonotic diseases in the world. Control of the disease in humans is dependent upon limiting the infection in animals through surveillance and vaccination. Given the dramatic economic and political changes that have taken place in the former Soviet Union, which have limited control, evaluating the status of human brucellosis in former Soviet states is crucial. We assessed annual spatial and temporal trends in the epidemiology of human brucellosis in Azerbaijan, 1983-2009, in conjunction with data from a livestock surveillance and control programme (2002-2009). To analyse trends, we used a combination of segmented regression and spatial analysis. From 1983 to 2009, a total of 11 233 cases of human brucellosis were reported. Up to the mid-1990s, the incidence of human brucellosis showed a pattern of re-emergence, increasing by 25% annually, on average. Following Soviet governance, the incidence rates peaked, increasing by 1.8% annually, on average, and subsequently decreasing by 5% annually, on average, during the period 2002-2009. Despite recent national declines in human incidence, we identified geographic changes in the case distribution characterized by a geographic expansion and an increasing incidence among districts clustered in the south-east, compared to a decrease of elsewhere in the country. Males were consistently, disproportionately afflicted (71%) and incidence was highest in the 15 to 19 age group (18.1 cases/100 000). During the period 2002-2009, >10 million small ruminants were vaccinated with Rev1. Our findings highlight the improving prospects for human brucellosis control following livestock vaccination; however, the disease appears to be re-emerging in south-eastern Azerbaijan. Sustained one health measures are needed to address changing patterns of brucellosis in Azerbaijan and elsewhere in the former Soviet Union. [ABSTRACT FROM AUTHOR]

Live, attenuated Salmonella Typhimurium vaccine candidate expressing BCSP31, Omp3b, and SOD proteins of Brucella abortus was constructed. Thirty BALB/c mice were divided equally into three groups, Group A, were intraperitoneally (IP) inoculated with 100 µl of approximately 1.2 x 106 colony-forming units (CFUs)/ml of the Salmonella containing vector only in 100 µl as a control. And groups B and C mice were orally and IP immunized with approximately 1.2 x 109 CFU/ml of the mixture of three delivery strains in 10 µl and IP immunized with approximately 1.2 x 106 CFU/ml of the mixture in 100 µl, respectively. The serum IgG, TNF-α and IFN-γ concentrations in groups B (except Omp3b) and C were significantly higher than those in group A. Following challenge with B. abortus strain 544; challenge strain was detected <10³ CFU from the spleen of all mice of group C. These results suggest that IP immunization with the mixture of the vaccine candidate can induce immune responses, and can effectively protect mice against brucellosis. [ABSTRACT FROM AUTHOR]

Brucellosis is one of the most widespread zoonosis in the world affecting many domestic and wild animals including bovines, goats, pigs and dogs. Each species of the Brucella genus has a particular tropism toward different mammals being the most relevant for human health Brucella abortus , Brucella melitensis and Brucella suis that infect bovines, goats/camelids and swine respectively. Although for B. abortus and B. melitensis there are vaccines available, there is no efficient vaccine to protect swine from B. suis infection so far. We describe here the construction of a novel vaccine strain that confers excellent protection against B. suis in a mouse model of infection. This strain is a clean deletion of the phosphoglucomutase ( pgm ) gene that codes for a protein that catalyzes the conversion of glucose-6-P to glucose-1-P, which is used as a precursor for the biosynthesis of many polysaccharides. The Delta- pgm strain lacks a complete lipopolysaccharide, is unable to synthesize cyclic beta glucans and is sensitive to several detergents and Polymyxin B. We show that this strain replicates in cultured cells, is completely avirulent in the mouse model of infection but protects against a challenge of the virulent strain inducing the production of pro-inflammatory cytokines. This novel strain could be an excellent candidate for the control of swine brucellosis, a disease of emerging concern in many parts of the world. [ABSTRACT FROM AUTHOR]

Brucellosis is a wide spread zoonotic disease that causes abortion and infertility in mammals and leads to debilitating, febrile illness in humans. Brucella abortus , Brucella melitensis and Brucella suis are the major pathogenic species to humans. Vaccination with live attenuated B. suis strain 2 (S2) vaccine is an essential and critical component in the control of brucellosis in China. The S2 vaccine is very effective in preventing brucellosis in goats, sheep, cattle and swine. However, there are still debates outside of China whether the S2 vaccine is able to provide protection against heterologous virulent Brucella species. We investigated the residual virulence, immunogenicity and protective efficacy of the S2 vaccine in BALB/c mice by determining bacteria persistence in spleen, serum antibody response, cellular immune response and protection against a heterologous virulent challenge. The S2 vaccine was of low virulence as there were no bacteria recovered in spleen four weeks post vaccination. The vaccinated mice developed Brucella -specific IgG in 2–3 weeks, and a burst production of IFN-γ at one week as well as a two-fold increase in TNF-α production. The S2 vaccine protected mice from a virulent challenge by B. melitensis M28, B. abortus 2308 and B. suis S1330, and the S2 vaccinated mice did not develop any clinical signs or tissue damage. Our study demonstrated that the S2 vaccine is of low virulence, stimulates good humoral and cellular immunity and protects animals against infection by heterologous, virulent Brucella species. [ABSTRACT FROM AUTHOR]

Purpose: At present, there is no vaccine available for the prevention of human brucellosis. Brucella outer membrane protein 2b (Omp2b) is a 36 kD porin existed in common Brucella pathogens and it is considered as priority antigen for designing a new subunit vaccine. Materials and Methods: In the current study, we aimed to predict and analyze the secondary and tertiary structures of the Brucella abortus Omp2b protein, and to predict T-cell and B-cell epitopes with the help of bioinformatics tools. Subsequently, cloning and expression of the short form of Omp2b (SOmp2b) was performed using pET28a expression vector and Escherichia coli BL21 host, respectively. The recombinant SOmp2b (rSOmp2b) was purified with Ni-NTA column. Results: The recombinant protein was successfully expressed in E. coli host and purified under denaturation conditions. The yield of the purified rSOmp2b was estimated by Bradford method and found to be 220 μg/mL of the culture. Conclusion: Our results indicate that Omp2b protein has a potential to induce both B-cell- and T-cell-mediated immune responses and it can be evaluated as a new subunit vaccine candidate against brucellosis. [ABSTRACT FROM AUTHOR]

Brucellae are Gram-negative intracellular bacteria that cause an important zoonotic disease called brucellosis. The animal vaccines are available but have disadvantage of causing abortions in a proportion of pregnant animals. The animal vaccines are also pathogenic to humans. Recent trend in vaccine design has shifted to epitope-based vaccines that are safe and specific. In this study, efforts were made to identify MHC-I- and MHC-II-restricted T cell epitopes of Brucella abortus and evaluate their vaccine potential in mice. The peptides were designed using online available immunoinformatics tools, and five MHC-I- and one MHC-II-restricted T cell peptides were selected on the basis of their ability to produce interferon gamma (IFN-γ) in in vivo studies. The selected peptides were co-administered with poly dl-lactide-co-glycolide (PLG) microparticles and evaluated for immunogenicity and protection in BALB/c mice. Mice immunized with peptides either entrapped in PLG microparticles (EPLG-Pep) or adsorbed on PLG particles (APLG-Pep) showed significantly higher splenocyte proliferation and IFN-γ generation to all selected peptides than the mice immunized with corresponding irrelevant peptides formulated PLG microparticles or phosphate-buffered saline (PBS). A significant protection compared to PBS control was also observed in EPLG-Pep and APLG-Pep groups. A plasmid DNA vaccine construct (pVaxPep) for peptides encoding DNA sequences was generated and injected to mice by in vivo electroporation. Significant protection was observed (1.66 protection units) when compared with PBS and empty vector control group animals. Overall, the MHC-I and MHC-II peptides identified in this study are immunogenic and protective in mouse model and support the feasibility of peptide-based vaccine for brucellosis. [ABSTRACT FROM AUTHOR]

Brucella abortus S19 and RB51 strains have been successfully used to control bovine brucellosis worldwide; however, currently, most of our understanding of the protective immune response induced by vaccination comes from studies in mice. The aim of this study was to characterize and compare the immune responses induced in cattle prime-immunized with B. abortus S19 or RB51 and revaccinated with RB51. Female calves, aged 4 to 8 months, were vaccinated with either vaccine S19 (0.6–1.2 x 1011 CFU) or RB51 (1.3 x 1010 CFU) on day 0, and revaccinated with RB51 (1.3 x 1010 CFU) on day 365 of the experiment. Characterization of the immune response was performed using serum and peripheral blood mononuclear cells. Blood samples were collected on days 0, 28, 210, 365, 393 and 575 post-immunization. Results showed that S19 and RB51 vaccination induced an immune response characterized by proliferation of CD4+ and CD8+ T-cells; IFN-ɣ and IL-17A production by CD4+ T-cells; cytotoxic CD8+ T-cells; IL-6 secretion; CD4+ and CD8+ memory cells; antibodies of IgG1 class; and expression of the phenotypes of activation in T-cells. However, the immune response stimulated by S19 compared to RB51 showed higher persistency of IFN-ɣ and CD4+ memory cells, induction of CD21+ memory cells and higher secretion of IL-6. After RB51 revaccination, the immune response was chiefly characterized by increase in IFN-ɣ expression, proliferation of antigen-specific CD4+ and CD8+ T-cells, cytotoxic CD8+ T-cells and decrease of IL-6 production in both groups. Nevertheless, a different polarization of the immune response, CD4+- or CD8+-dominant, was observed after the booster with RB51 for S19 and RB51 prime-vaccinated animals, respectively. Our results indicate that after prime vaccination both vaccine strains induce a strong and complex Th1 immune response, although after RB51 revaccination the differences between immune profiles induced by prime-vaccination become accentuated. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate protection induced by the vaccine candidate B. ovis ΔabcBA against experimental challenge with wild type B. ovis in rams. Rams were subcutaneously immunized with B. ovis ΔabcBA encapsulated with sterile alginate or with the non encapsulated vaccine strain. Serum, urine, and semen samples were collected during two months after immunization. The rams were then challenged with wild type B. ovis (ATCC25840), and the results were compared to non immunized and experimentally challenged rams. Immunization, particularly with encapsulated B. ovis ΔabcBA, prevented infection, secretion of wild type B. ovis in the semen and urine, shedding of neutrophils in the semen, and the development of clinical changes, gross and microscopic lesions induced by the wild type B. ovis reference strain. Collectively, our data indicates that the B. ovis ΔabcBA strain is an exceptionally good vaccine strain for preventing brucellosis caused by B. ovis infection in rams. [ABSTRACT FROM AUTHOR]

Brucella abortus live vaccines have been used successfully to control bovine brucellosis worldwide for decades. However, due to some limitations of these live vaccines, efforts are being made for the development of new safer and more effective vaccines that could also be used in other susceptible species. In this context, understanding the protective immune responses triggered by B. abortus is critical for the development of new vaccines. Such understandings will enhance our knowledge of the host/pathogen interactions and enable to develop methods to evaluate potential vaccines and innovative treatments for animals or humans. At present, almost all the knowledge regarding B. abortus specific immunological responses comes from studies in mice. Active participation of macrophages, dendritic cells, IFN-γ producing CD4 + T-cells and cytotoxic CD8 + T-cells are vital to overcome the infection. In this review, we discuss the characteristics of the immune responses triggered by vaccination versus infection by B. abortus , in different hosts. [ABSTRACT FROM AUTHOR]

Trás-os-Montes e Alto Douro, in the northeastern region of Portugal, previously exhibited the highest brucellosis prevalence in the entire small ruminant population of Portugal. Consequently, a vaccination program of the whole population with Brucella melitensis Rev-1 was carried out from 2001 to 2004, and further compulsory Rev-1 vaccination of 3- to 6-month-old lambs and kids was carried out between 2005 and 2007. The prevalence of brucellosis decreased by 71.42% in 2004, with a 2-fold decrease occurring from 2005 to 2007. The reduction of brucellosis prevalence was statistically significant (P < 0.001) according to flock size. By species, brucellosis prevalence decreased 14.5-fold in sheep and 5.5-fold in goats in 2004. Regarding flock constitution, it decreased by 77% for pure flocks and 73% in mixed flocks in 2004. Regarding the animals involved in production, brucellosis prevalence decreased during the 7-year period. It was concluded that Rev-1 vaccination of the whole population was effective in decreasing brucellosis prevalence. These results contribute to the scarce information available regarding the effect of Rev-1 vaccination on different characteristics of flocks. They may be used to improve the efficiency of brucellosis eradication programs within livestock management. [ABSTRACT FROM AUTHOR]